1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
4	* Written by Alex Tomas <alex@clusterfs.com>
5	*/
6
7
8	/*
9	* mballoc.c contains the multiblocks allocation routines
10	*/
11
12	#include "ext4_jbd2.h"
13	#include "mballoc.h"
14	#include <linux/log2.h>
15	#include <linux/module.h>
16	#include <linux/slab.h>
17	#include <linux/nospec.h>
18	#include <linux/backing-dev.h>
19	#include <linux/freezer.h>
20	#include <trace/events/ext4.h>
21	#include <kunit/static_stub.h>
22
23	/*
24	* MUSTDO:
25	* - test ext4_ext_search_left() and ext4_ext_search_right()
26	* - search for metadata in few groups
27	*
28	* TODO v4:
29	* - normalization should take into account whether file is still open
30	* - discard preallocations if no free space left (policy?)
31	* - don't normalize tails
32	* - quota
33	* - reservation for superuser
34	*
35	* TODO v3:
36	* - bitmap read-ahead (proposed by Oleg Drokin aka green)
37	* - track min/max extents in each group for better group selection
38	* - mb_mark_used() may allocate chunk right after splitting buddy
39	* - tree of groups sorted by number of free blocks
40	* - error handling
41	*/
42
43	/*
44	* The allocation request involve request for multiple number of blocks
45	* near to the goal(block) value specified.
46	*
47	* During initialization phase of the allocator we decide to use the
48	* group preallocation or inode preallocation depending on the size of
49	* the file. The size of the file could be the resulting file size we
50	* would have after allocation, or the current file size, which ever
51	* is larger. If the size is less than sbi->s_mb_stream_request we
52	* select to use the group preallocation. The default value of
53	* s_mb_stream_request is 16 blocks. This can also be tuned via
54	* /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in
55	* terms of number of blocks.
56	*
57	* The main motivation for having small file use group preallocation is to
58	* ensure that we have small files closer together on the disk.
59	*
60	* First stage the allocator looks at the inode prealloc list,
61	* ext4_inode_info->i_prealloc_list, which contains list of prealloc
62	* spaces for this particular inode. The inode prealloc space is
63	* represented as:
64	*
65	* pa_lstart -> the logical start block for this prealloc space
66	* pa_pstart -> the physical start block for this prealloc space
67	* pa_len -> length for this prealloc space (in clusters)
68	* pa_free -> free space available in this prealloc space (in clusters)
69	*
70	* The inode preallocation space is used looking at the _logical_ start
71	* block. If only the logical file block falls within the range of prealloc
72	* space we will consume the particular prealloc space. This makes sure that
73	* we have contiguous physical blocks representing the file blocks
74	*
75	* The important thing to be noted in case of inode prealloc space is that
76	* we don't modify the values associated to inode prealloc space except
77	* pa_free.
78	*
79	* If we are not able to find blocks in the inode prealloc space and if we
80	* have the group allocation flag set then we look at the locality group
81	* prealloc space. These are per CPU prealloc list represented as
82	*
83	* ext4_sb_info.s_locality_groups[smp_processor_id()]
84	*
85	* The reason for having a per cpu locality group is to reduce the contention
86	* between CPUs. It is possible to get scheduled at this point.
87	*
88	* The locality group prealloc space is used looking at whether we have
89	* enough free space (pa_free) within the prealloc space.
90	*
91	* If we can't allocate blocks via inode prealloc or/and locality group
92	* prealloc then we look at the buddy cache. The buddy cache is represented
93	* by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
94	* mapped to the buddy and bitmap information regarding different
95	* groups. The buddy information is attached to buddy cache inode so that
96	* we can access them through the page cache. The information regarding
97	* each group is loaded via ext4_mb_load_buddy. The information involve
98	* block bitmap and buddy information. The information are stored in the
99	* inode as:
100	*
101	* { page }
102	* [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
103	*
104	*
105	* one block each for bitmap and buddy information. So for each group we
106	* take up 2 blocks. A page can contain blocks_per_page (PAGE_SIZE /
107	* blocksize) blocks. So it can have information regarding groups_per_page
108	* which is blocks_per_page/2
109	*
110	* The buddy cache inode is not stored on disk. The inode is thrown
111	* away when the filesystem is unmounted.
112	*
113	* We look for count number of blocks in the buddy cache. If we were able
114	* to locate that many free blocks we return with additional information
115	* regarding rest of the contiguous physical block available
116	*
117	* Before allocating blocks via buddy cache we normalize the request
118	* blocks. This ensure we ask for more blocks that we needed. The extra
119	* blocks that we get after allocation is added to the respective prealloc
120	* list. In case of inode preallocation we follow a list of heuristics
121	* based on file size. This can be found in ext4_mb_normalize_request. If
122	* we are doing a group prealloc we try to normalize the request to
123	* sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is
124	* dependent on the cluster size; for non-bigalloc file systems, it is
125	* 512 blocks. This can be tuned via
126	* /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in
127	* terms of number of blocks. If we have mounted the file system with -O
128	* stripe=<value> option the group prealloc request is normalized to the
129	* smallest multiple of the stripe value (sbi->s_stripe) which is
130	* greater than the default mb_group_prealloc.
131	*
132	* If "mb_optimize_scan" mount option is set, we maintain in memory group info
133	* structures in two data structures:
134	*
135	* 1) Array of largest free order lists (sbi->s_mb_largest_free_orders)
136	*
137	* Locking: sbi->s_mb_largest_free_orders_locks(array of rw locks)
138	*
139	* This is an array of lists where the index in the array represents the
140	* largest free order in the buddy bitmap of the participating group infos of
141	* that list. So, there are exactly MB_NUM_ORDERS(sb) (which means total
142	* number of buddy bitmap orders possible) number of lists. Group-infos are
143	* placed in appropriate lists.
144	*
145	* 2) Average fragment size lists (sbi->s_mb_avg_fragment_size)
146	*
147	* Locking: sbi->s_mb_avg_fragment_size_locks(array of rw locks)
148	*
149	* This is an array of lists where in the i-th list there are groups with
150	* average fragment size >= 2^i and < 2^(i+1). The average fragment size
151	* is computed as ext4_group_info->bb_free / ext4_group_info->bb_fragments.
152	* Note that we don't bother with a special list for completely empty groups
153	* so we only have MB_NUM_ORDERS(sb) lists.
154	*
155	* When "mb_optimize_scan" mount option is set, mballoc consults the above data
156	* structures to decide the order in which groups are to be traversed for
157	* fulfilling an allocation request.
158	*
159	* At CR_POWER2_ALIGNED , we look for groups which have the largest_free_order
160	* >= the order of the request. We directly look at the largest free order list
161	* in the data structure (1) above where largest_free_order = order of the
162	* request. If that list is empty, we look at remaining list in the increasing
163	* order of largest_free_order. This allows us to perform CR_POWER2_ALIGNED
164	* lookup in O(1) time.
165	*
166	* At CR_GOAL_LEN_FAST, we only consider groups where
167	* average fragment size > request size. So, we lookup a group which has average
168	* fragment size just above or equal to request size using our average fragment
169	* size group lists (data structure 2) in O(1) time.
170	*
171	* At CR_BEST_AVAIL_LEN, we aim to optimize allocations which can't be satisfied
172	* in CR_GOAL_LEN_FAST. The fact that we couldn't find a group in
173	* CR_GOAL_LEN_FAST suggests that there is no BG that has avg
174	* fragment size > goal length. So before falling to the slower
175	* CR_GOAL_LEN_SLOW, in CR_BEST_AVAIL_LEN we proactively trim goal length and
176	* then use the same fragment lists as CR_GOAL_LEN_FAST to find a BG with a big
177	* enough average fragment size. This increases the chances of finding a
178	* suitable block group in O(1) time and results in faster allocation at the
179	* cost of reduced size of allocation.
180	*
181	* If "mb_optimize_scan" mount option is not set, mballoc traverses groups in
182	* linear order which requires O(N) search time for each CR_POWER2_ALIGNED and
183	* CR_GOAL_LEN_FAST phase.
184	*
185	* The regular allocator (using the buddy cache) supports a few tunables.
186	*
187	* /sys/fs/ext4/<partition>/mb_min_to_scan
188	* /sys/fs/ext4/<partition>/mb_max_to_scan
189	* /sys/fs/ext4/<partition>/mb_order2_req
190	* /sys/fs/ext4/<partition>/mb_max_linear_groups
191	*
192	* The regular allocator uses buddy scan only if the request len is power of
193	* 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
194	* value of s_mb_order2_reqs can be tuned via
195	* /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to
196	* stripe size (sbi->s_stripe), we try to search for contiguous block in
197	* stripe size. This should result in better allocation on RAID setups. If
198	* not, we search in the specific group using bitmap for best extents. The
199	* tunable min_to_scan and max_to_scan control the behaviour here.
200	* min_to_scan indicate how long the mballoc __must__ look for a best
201	* extent and max_to_scan indicates how long the mballoc __can__ look for a
202	* best extent in the found extents. Searching for the blocks starts with
203	* the group specified as the goal value in allocation context via
204	* ac_g_ex. Each group is first checked based on the criteria whether it
205	* can be used for allocation. ext4_mb_good_group explains how the groups are
206	* checked.
207	*
208	* When "mb_optimize_scan" is turned on, as mentioned above, the groups may not
209	* get traversed linearly. That may result in subsequent allocations being not
210	* close to each other. And so, the underlying device may get filled up in a
211	* non-linear fashion. While that may not matter on non-rotational devices, for
212	* rotational devices that may result in higher seek times. "mb_max_linear_groups"
213	* tells mballoc how many groups mballoc should search linearly before
214	* performing consulting above data structures for more efficient lookups. For
215	* non rotational devices, this value defaults to 0 and for rotational devices
216	* this is set to MB_DEFAULT_LINEAR_LIMIT.
217	*
218	* Both the prealloc space are getting populated as above. So for the first
219	* request we will hit the buddy cache which will result in this prealloc
220	* space getting filled. The prealloc space is then later used for the
221	* subsequent request.
222	*/
223
224	/*
225	* mballoc operates on the following data:
226	* - on-disk bitmap
227	* - in-core buddy (actually includes buddy and bitmap)
228	* - preallocation descriptors (PAs)
229	*
230	* there are two types of preallocations:
231	* - inode
232	* assiged to specific inode and can be used for this inode only.
233	* it describes part of inode's space preallocated to specific
234	* physical blocks. any block from that preallocated can be used
235	* independent. the descriptor just tracks number of blocks left
236	* unused. so, before taking some block from descriptor, one must
237	* make sure corresponded logical block isn't allocated yet. this
238	* also means that freeing any block within descriptor's range
239	* must discard all preallocated blocks.
240	* - locality group
241	* assigned to specific locality group which does not translate to
242	* permanent set of inodes: inode can join and leave group. space
243	* from this type of preallocation can be used for any inode. thus
244	* it's consumed from the beginning to the end.
245	*
246	* relation between them can be expressed as:
247	* in-core buddy = on-disk bitmap + preallocation descriptors
248	*
249	* this mean blocks mballoc considers used are:
250	* - allocated blocks (persistent)
251	* - preallocated blocks (non-persistent)
252	*
253	* consistency in mballoc world means that at any time a block is either
254	* free or used in ALL structures. notice: "any time" should not be read
255	* literally -- time is discrete and delimited by locks.
256	*
257	* to keep it simple, we don't use block numbers, instead we count number of
258	* blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
259	*
260	* all operations can be expressed as:
261	* - init buddy: buddy = on-disk + PAs
262	* - new PA: buddy += N; PA = N
263	* - use inode PA: on-disk += N; PA -= N
264	* - discard inode PA buddy -= on-disk - PA; PA = 0
265	* - use locality group PA on-disk += N; PA -= N
266	* - discard locality group PA buddy -= PA; PA = 0
267	* note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
268	* is used in real operation because we can't know actual used
269	* bits from PA, only from on-disk bitmap
270	*
271	* if we follow this strict logic, then all operations above should be atomic.
272	* given some of them can block, we'd have to use something like semaphores
273	* killing performance on high-end SMP hardware. let's try to relax it using
274	* the following knowledge:
275	* 1) if buddy is referenced, it's already initialized
276	* 2) while block is used in buddy and the buddy is referenced,
277	* nobody can re-allocate that block
278	* 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
279	* bit set and PA claims same block, it's OK. IOW, one can set bit in
280	* on-disk bitmap if buddy has same bit set or/and PA covers corresponded
281	* block
282	*
283	* so, now we're building a concurrency table:
284	* - init buddy vs.
285	* - new PA
286	* blocks for PA are allocated in the buddy, buddy must be referenced
287	* until PA is linked to allocation group to avoid concurrent buddy init
288	* - use inode PA
289	* we need to make sure that either on-disk bitmap or PA has uptodate data
290	* given (3) we care that PA-=N operation doesn't interfere with init
291	* - discard inode PA
292	* the simplest way would be to have buddy initialized by the discard
293	* - use locality group PA
294	* again PA-=N must be serialized with init
295	* - discard locality group PA
296	* the simplest way would be to have buddy initialized by the discard
297	* - new PA vs.
298	* - use inode PA
299	* i_data_sem serializes them
300	* - discard inode PA
301	* discard process must wait until PA isn't used by another process
302	* - use locality group PA
303	* some mutex should serialize them
304	* - discard locality group PA
305	* discard process must wait until PA isn't used by another process
306	* - use inode PA
307	* - use inode PA
308	* i_data_sem or another mutex should serializes them
309	* - discard inode PA
310	* discard process must wait until PA isn't used by another process
311	* - use locality group PA
312	* nothing wrong here -- they're different PAs covering different blocks
313	* - discard locality group PA
314	* discard process must wait until PA isn't used by another process
315	*
316	* now we're ready to make few consequences:
317	* - PA is referenced and while it is no discard is possible
318	* - PA is referenced until block isn't marked in on-disk bitmap
319	* - PA changes only after on-disk bitmap
320	* - discard must not compete with init. either init is done before
321	* any discard or they're serialized somehow
322	* - buddy init as sum of on-disk bitmap and PAs is done atomically
323	*
324	* a special case when we've used PA to emptiness. no need to modify buddy
325	* in this case, but we should care about concurrent init
326	*
327	*/
328
329	/*
330	* Logic in few words:
331	*
332	* - allocation:
333	* load group
334	* find blocks
335	* mark bits in on-disk bitmap
336	* release group
337	*
338	* - use preallocation:
339	* find proper PA (per-inode or group)
340	* load group
341	* mark bits in on-disk bitmap
342	* release group
343	* release PA
344	*
345	* - free:
346	* load group
347	* mark bits in on-disk bitmap
348	* release group
349	*
350	* - discard preallocations in group:
351	* mark PAs deleted
352	* move them onto local list
353	* load on-disk bitmap
354	* load group
355	* remove PA from object (inode or locality group)
356	* mark free blocks in-core
357	*
358	* - discard inode's preallocations:
359	*/
360
361	/*
362	* Locking rules
363	*
364	* Locks:
365	* - bitlock on a group (group)
366	* - object (inode/locality) (object)
367	* - per-pa lock (pa)
368	* - cr_power2_aligned lists lock (cr_power2_aligned)
369	* - cr_goal_len_fast lists lock (cr_goal_len_fast)
370	*
371	* Paths:
372	* - new pa
373	* object
374	* group
375	*
376	* - find and use pa:
377	* pa
378	*
379	* - release consumed pa:
380	* pa
381	* group
382	* object
383	*
384	* - generate in-core bitmap:
385	* group
386	* pa
387	*
388	* - discard all for given object (inode, locality group):
389	* object
390	* pa
391	* group
392	*
393	* - discard all for given group:
394	* group
395	* pa
396	* group
397	* object
398	*
399	* - allocation path (ext4_mb_regular_allocator)
400	* group
401	* cr_power2_aligned/cr_goal_len_fast
402	*/
403	static struct kmem_cache *ext4_pspace_cachep;
404	static struct kmem_cache *ext4_ac_cachep;
405	static struct kmem_cache *ext4_free_data_cachep;
406
407	/* We create slab caches for groupinfo data structures based on the
408	* superblock block size. There will be one per mounted filesystem for
409	* each unique s_blocksize_bits */
410	#define NR_GRPINFO_CACHES 8
411	static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES];
412
413	static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
414	"ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k",
415	"ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k",
416	"ext4_groupinfo_64k", "ext4_groupinfo_128k"
417	};
418
419	static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
420	ext4_group_t group);
421	static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac);
422
423	static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
424	ext4_group_t group, enum criteria cr);
425
426	static int ext4_try_to_trim_range(struct super_block *sb,
427	struct ext4_buddy *e4b, ext4_grpblk_t start,
428	ext4_grpblk_t max, ext4_grpblk_t minblocks);
429
430	/*
431	* The algorithm using this percpu seq counter goes below:
432	* 1. We sample the percpu discard_pa_seq counter before trying for block
433	* allocation in ext4_mb_new_blocks().
434	* 2. We increment this percpu discard_pa_seq counter when we either allocate
435	* or free these blocks i.e. while marking those blocks as used/free in
436	* mb_mark_used()/mb_free_blocks().
437	* 3. We also increment this percpu seq counter when we successfully identify
438	* that the bb_prealloc_list is not empty and hence proceed for discarding
439	* of those PAs inside ext4_mb_discard_group_preallocations().
440	*
441	* Now to make sure that the regular fast path of block allocation is not
442	* affected, as a small optimization we only sample the percpu seq counter
443	* on that cpu. Only when the block allocation fails and when freed blocks
444	* found were 0, that is when we sample percpu seq counter for all cpus using
445	* below function ext4_get_discard_pa_seq_sum(). This happens after making
446	* sure that all the PAs on grp->bb_prealloc_list got freed or if it's empty.
447	*/
448	static DEFINE_PER_CPU(u64, discard_pa_seq);
449	static inline u64 ext4_get_discard_pa_seq_sum(void)
450	{
451	int __cpu;
452	u64 __seq = 0;
453
454	for_each_possible_cpu(__cpu)
455	__seq += per_cpu(discard_pa_seq, __cpu);
456	return __seq;
457	}
458
459	static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
460	{
461	#if BITS_PER_LONG == 64
462	*bit += ((unsigned long) addr & 7UL) << 3;
463	addr = (void *) ((unsigned long) addr & ~7UL);
464	#elif BITS_PER_LONG == 32
465	*bit += ((unsigned long) addr & 3UL) << 3;
466	addr = (void *) ((unsigned long) addr & ~3UL);
467	#else
468	#error "how many bits you are?!"
469	#endif
470	return addr;
471	}
472
473	static inline int mb_test_bit(int bit, void *addr)
474	{
475	/*
476	* ext4_test_bit on architecture like powerpc
477	* needs unsigned long aligned address
478	*/
479	addr = mb_correct_addr_and_bit(bit: &bit, addr);
480	return ext4_test_bit(nr: bit, addr);
481	}
482
483	static inline void mb_set_bit(int bit, void *addr)
484	{
485	addr = mb_correct_addr_and_bit(bit: &bit, addr);
486	ext4_set_bit(nr: bit, addr);
487	}
488
489	static inline void mb_clear_bit(int bit, void *addr)
490	{
491	addr = mb_correct_addr_and_bit(bit: &bit, addr);
492	ext4_clear_bit(nr: bit, addr);
493	}
494
495	static inline int mb_test_and_clear_bit(int bit, void *addr)
496	{
497	addr = mb_correct_addr_and_bit(bit: &bit, addr);
498	return ext4_test_and_clear_bit(nr: bit, addr);
499	}
500
501	static inline int mb_find_next_zero_bit(void *addr, int max, int start)
502	{
503	int fix = 0, ret, tmpmax;
504	addr = mb_correct_addr_and_bit(bit: &fix, addr);
505	tmpmax = max + fix;
506	start += fix;
507
508	ret = ext4_find_next_zero_bit(addr, size: tmpmax, offset: start) - fix;
509	if (ret > max)
510	return max;
511	return ret;
512	}
513
514	static inline int mb_find_next_bit(void *addr, int max, int start)
515	{
516	int fix = 0, ret, tmpmax;
517	addr = mb_correct_addr_and_bit(bit: &fix, addr);
518	tmpmax = max + fix;
519	start += fix;
520
521	ret = ext4_find_next_bit(addr, size: tmpmax, offset: start) - fix;
522	if (ret > max)
523	return max;
524	return ret;
525	}
526
527	static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
528	{
529	char *bb;
530
531	BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
532	BUG_ON(max == NULL);
533
534	if (order > e4b->bd_blkbits + 1) {
535	*max = 0;
536	return NULL;
537	}
538
539	/* at order 0 we see each particular block */
540	if (order == 0) {
541	*max = 1 << (e4b->bd_blkbits + 3);
542	return e4b->bd_bitmap;
543	}
544
545	bb = e4b->bd_buddy + EXT4_SB(sb: e4b->bd_sb)->s_mb_offsets[order];
546	*max = EXT4_SB(sb: e4b->bd_sb)->s_mb_maxs[order];
547
548	return bb;
549	}
550
551	#ifdef DOUBLE_CHECK
552	static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
553	int first, int count)
554	{
555	int i;
556	struct super_block *sb = e4b->bd_sb;
557
558	if (unlikely(e4b->bd_info->bb_bitmap == NULL))
559	return;
560	assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
561	for (i = 0; i < count; i++) {
562	if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
563	ext4_fsblk_t blocknr;
564
565	blocknr = ext4_group_first_block_no(sb, e4b->bd_group);
566	blocknr += EXT4_C2B(EXT4_SB(sb), first + i);
567	ext4_mark_group_bitmap_corrupted(sb, e4b->bd_group,
568	EXT4_GROUP_INFO_BBITMAP_CORRUPT);
569	ext4_grp_locked_error(sb, e4b->bd_group,
570	inode ? inode->i_ino : 0,
571	blocknr,
572	"freeing block already freed "
573	"(bit %u)",
574	first + i);
575	}
576	mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
577	}
578	}
579
580	static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
581	{
582	int i;
583
584	if (unlikely(e4b->bd_info->bb_bitmap == NULL))
585	return;
586	assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
587	for (i = 0; i < count; i++) {
588	BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
589	mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
590	}
591	}
592
593	static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
594	{
595	if (unlikely(e4b->bd_info->bb_bitmap == NULL))
596	return;
597	if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
598	unsigned char *b1, *b2;
599	int i;
600	b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
601	b2 = (unsigned char *) bitmap;
602	for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
603	if (b1[i] != b2[i]) {
604	ext4_msg(e4b->bd_sb, KERN_ERR,
605	"corruption in group %u "
606	"at byte %u(%u): %x in copy != %x "
607	"on disk/prealloc",
608	e4b->bd_group, i, i * 8, b1[i], b2[i]);
609	BUG();
610	}
611	}
612	}
613	}
614
615	static void mb_group_bb_bitmap_alloc(struct super_block *sb,
616	struct ext4_group_info *grp, ext4_group_t group)
617	{
618	struct buffer_head *bh;
619
620	grp->bb_bitmap = kmalloc(sb->s_blocksize, GFP_NOFS);
621	if (!grp->bb_bitmap)
622	return;
623
624	bh = ext4_read_block_bitmap(sb, group);
625	if (IS_ERR_OR_NULL(bh)) {
626	kfree(grp->bb_bitmap);
627	grp->bb_bitmap = NULL;
628	return;
629	}
630
631	memcpy(grp->bb_bitmap, bh->b_data, sb->s_blocksize);
632	put_bh(bh);
633	}
634
635	static void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
636	{
637	kfree(grp->bb_bitmap);
638	}
639
640	#else
641	static inline void mb_free_blocks_double(struct inode *inode,
642	struct ext4_buddy *e4b, int first, int count)
643	{
644	return;
645	}
646	static inline void mb_mark_used_double(struct ext4_buddy *e4b,
647	int first, int count)
648	{
649	return;
650	}
651	static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
652	{
653	return;
654	}
655
656	static inline void mb_group_bb_bitmap_alloc(struct super_block *sb,
657	struct ext4_group_info *grp, ext4_group_t group)
658	{
659	return;
660	}
661
662	static inline void mb_group_bb_bitmap_free(struct ext4_group_info *grp)
663	{
664	return;
665	}
666	#endif
667
668	#ifdef AGGRESSIVE_CHECK
669
670	#define MB_CHECK_ASSERT(assert) \
671	do { \
672	if (!(assert)) { \
673	printk(KERN_EMERG \
674	"Assertion failure in %s() at %s:%d: \"%s\"\n", \
675	function, file, line, # assert); \
676	BUG(); \
677	} \
678	} while (0)
679
680	static void __mb_check_buddy(struct ext4_buddy *e4b, char *file,
681	const char *function, int line)
682	{
683	struct super_block *sb = e4b->bd_sb;
684	int order = e4b->bd_blkbits + 1;
685	int max;
686	int max2;
687	int i;
688	int j;
689	int k;
690	int count;
691	struct ext4_group_info *grp;
692	int fragments = 0;
693	int fstart;
694	struct list_head *cur;
695	void *buddy;
696	void *buddy2;
697
698	if (e4b->bd_info->bb_check_counter++ % 10)
699	return;
700
701	while (order > 1) {
702	buddy = mb_find_buddy(e4b, order, &max);
703	MB_CHECK_ASSERT(buddy);
704	buddy2 = mb_find_buddy(e4b, order - 1, &max2);
705	MB_CHECK_ASSERT(buddy2);
706	MB_CHECK_ASSERT(buddy != buddy2);
707	MB_CHECK_ASSERT(max * 2 == max2);
708
709	count = 0;
710	for (i = 0; i < max; i++) {
711
712	if (mb_test_bit(i, buddy)) {
713	/* only single bit in buddy2 may be 0 */
714	if (!mb_test_bit(i << 1, buddy2)) {
715	MB_CHECK_ASSERT(
716	mb_test_bit((i<<1)+1, buddy2));
717	}
718	continue;
719	}
720
721	/* both bits in buddy2 must be 1 */
722	MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
723	MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
724
725	for (j = 0; j < (1 << order); j++) {
726	k = (i * (1 << order)) + j;
727	MB_CHECK_ASSERT(
728	!mb_test_bit(k, e4b->bd_bitmap));
729	}
730	count++;
731	}
732	MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
733	order--;
734	}
735
736	fstart = -1;
737	buddy = mb_find_buddy(e4b, 0, &max);
738	for (i = 0; i < max; i++) {
739	if (!mb_test_bit(i, buddy)) {
740	MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
741	if (fstart == -1) {
742	fragments++;
743	fstart = i;
744	}
745	continue;
746	}
747	fstart = -1;
748	/* check used bits only */
749	for (j = 0; j < e4b->bd_blkbits + 1; j++) {
750	buddy2 = mb_find_buddy(e4b, j, &max2);
751	k = i >> j;
752	MB_CHECK_ASSERT(k < max2);
753	MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
754	}
755	}
756	MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
757	MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
758
759	grp = ext4_get_group_info(sb, e4b->bd_group);
760	if (!grp)
761	return;
762	list_for_each(cur, &grp->bb_prealloc_list) {
763	ext4_group_t groupnr;
764	struct ext4_prealloc_space *pa;
765	pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
766	ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
767	MB_CHECK_ASSERT(groupnr == e4b->bd_group);
768	for (i = 0; i < pa->pa_len; i++)
769	MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
770	}
771	}
772	#undef MB_CHECK_ASSERT
773	#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
774	__FILE__, __func__, __LINE__)
775	#else
776	#define mb_check_buddy(e4b)
777	#endif
778
779	/*
780	* Divide blocks started from @first with length @len into
781	* smaller chunks with power of 2 blocks.
782	* Clear the bits in bitmap which the blocks of the chunk(s) covered,
783	* then increase bb_counters[] for corresponded chunk size.
784	*/
785	static void ext4_mb_mark_free_simple(struct super_block *sb,
786	void *buddy, ext4_grpblk_t first, ext4_grpblk_t len,
787	struct ext4_group_info *grp)
788	{
789	struct ext4_sb_info *sbi = EXT4_SB(sb);
790	ext4_grpblk_t min;
791	ext4_grpblk_t max;
792	ext4_grpblk_t chunk;
793	unsigned int border;
794
795	BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb));
796
797	border = 2 << sb->s_blocksize_bits;
798
799	while (len > 0) {
800	/* find how many blocks can be covered since this position */
801	max = ffs(first | border) - 1;
802
803	/* find how many blocks of power 2 we need to mark */
804	min = fls(x: len) - 1;
805
806	if (max < min)
807	min = max;
808	chunk = 1 << min;
809
810	/* mark multiblock chunks only */
811	grp->bb_counters[min]++;
812	if (min > 0)
813	mb_clear_bit(bit: first >> min,
814	addr: buddy + sbi->s_mb_offsets[min]);
815
816	len -= chunk;
817	first += chunk;
818	}
819	}
820
821	static int mb_avg_fragment_size_order(struct super_block *sb, ext4_grpblk_t len)
822	{
823	int order;
824
825	/*
826	* We don't bother with a special lists groups with only 1 block free
827	* extents and for completely empty groups.
828	*/
829	order = fls(x: len) - 2;
830	if (order < 0)
831	return 0;
832	if (order == MB_NUM_ORDERS(sb))
833	order--;
834	if (WARN_ON_ONCE(order > MB_NUM_ORDERS(sb)))
835	order = MB_NUM_ORDERS(sb) - 1;
836	return order;
837	}
838
839	/* Move group to appropriate avg_fragment_size list */
840	static void
841	mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp)
842	{
843	struct ext4_sb_info *sbi = EXT4_SB(sb);
844	int new_order;
845
846	if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_fragments == 0)
847	return;
848
849	new_order = mb_avg_fragment_size_order(sb,
850	len: grp->bb_free / grp->bb_fragments);
851	if (new_order == grp->bb_avg_fragment_size_order)
852	return;
853
854	if (grp->bb_avg_fragment_size_order != -1) {
855	write_lock(&sbi->s_mb_avg_fragment_size_locks[
856	grp->bb_avg_fragment_size_order]);
857	list_del(entry: &grp->bb_avg_fragment_size_node);
858	write_unlock(&sbi->s_mb_avg_fragment_size_locks[
859	grp->bb_avg_fragment_size_order]);
860	}
861	grp->bb_avg_fragment_size_order = new_order;
862	write_lock(&sbi->s_mb_avg_fragment_size_locks[
863	grp->bb_avg_fragment_size_order]);
864	list_add_tail(new: &grp->bb_avg_fragment_size_node,
865	head: &sbi->s_mb_avg_fragment_size[grp->bb_avg_fragment_size_order]);
866	write_unlock(&sbi->s_mb_avg_fragment_size_locks[
867	grp->bb_avg_fragment_size_order]);
868	}
869
870	/*
871	* Choose next group by traversing largest_free_order lists. Updates *new_cr if
872	* cr level needs an update.
873	*/
874	static void ext4_mb_choose_next_group_p2_aligned(struct ext4_allocation_context *ac,
875	enum criteria *new_cr, ext4_group_t *group)
876	{
877	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
878	struct ext4_group_info *iter;
879	int i;
880
881	if (ac->ac_status == AC_STATUS_FOUND)
882	return;
883
884	if (unlikely(sbi->s_mb_stats && ac->ac_flags & EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED))
885	atomic_inc(v: &sbi->s_bal_p2_aligned_bad_suggestions);
886
887	for (i = ac->ac_2order; i < MB_NUM_ORDERS(ac->ac_sb); i++) {
888	if (list_empty(head: &sbi->s_mb_largest_free_orders[i]))
889	continue;
890	read_lock(&sbi->s_mb_largest_free_orders_locks[i]);
891	if (list_empty(head: &sbi->s_mb_largest_free_orders[i])) {
892	read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
893	continue;
894	}
895	list_for_each_entry(iter, &sbi->s_mb_largest_free_orders[i],
896	bb_largest_free_order_node) {
897	if (sbi->s_mb_stats)
898	atomic64_inc(v: &sbi->s_bal_cX_groups_considered[CR_POWER2_ALIGNED]);
899	if (likely(ext4_mb_good_group(ac, iter->bb_group, CR_POWER2_ALIGNED))) {
900	*group = iter->bb_group;
901	ac->ac_flags |= EXT4_MB_CR_POWER2_ALIGNED_OPTIMIZED;
902	read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
903	return;
904	}
905	}
906	read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
907	}
908
909	/* Increment cr and search again if no group is found */
910	*new_cr = CR_GOAL_LEN_FAST;
911	}
912
913	/*
914	* Find a suitable group of given order from the average fragments list.
915	*/
916	static struct ext4_group_info *
917	ext4_mb_find_good_group_avg_frag_lists(struct ext4_allocation_context *ac, int order)
918	{
919	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
920	struct list_head *frag_list = &sbi->s_mb_avg_fragment_size[order];
921	rwlock_t *frag_list_lock = &sbi->s_mb_avg_fragment_size_locks[order];
922	struct ext4_group_info *grp = NULL, *iter;
923	enum criteria cr = ac->ac_criteria;
924
925	if (list_empty(head: frag_list))
926	return NULL;
927	read_lock(frag_list_lock);
928	if (list_empty(head: frag_list)) {
929	read_unlock(frag_list_lock);
930	return NULL;
931	}
932	list_for_each_entry(iter, frag_list, bb_avg_fragment_size_node) {
933	if (sbi->s_mb_stats)
934	atomic64_inc(v: &sbi->s_bal_cX_groups_considered[cr]);
935	if (likely(ext4_mb_good_group(ac, iter->bb_group, cr))) {
936	grp = iter;
937	break;
938	}
939	}
940	read_unlock(frag_list_lock);
941	return grp;
942	}
943
944	/*
945	* Choose next group by traversing average fragment size list of suitable
946	* order. Updates *new_cr if cr level needs an update.
947	*/
948	static void ext4_mb_choose_next_group_goal_fast(struct ext4_allocation_context *ac,
949	enum criteria *new_cr, ext4_group_t *group)
950	{
951	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
952	struct ext4_group_info *grp = NULL;
953	int i;
954
955	if (unlikely(ac->ac_flags & EXT4_MB_CR_GOAL_LEN_FAST_OPTIMIZED)) {
956	if (sbi->s_mb_stats)
957	atomic_inc(v: &sbi->s_bal_goal_fast_bad_suggestions);
958	}
959
960	for (i = mb_avg_fragment_size_order(sb: ac->ac_sb, len: ac->ac_g_ex.fe_len);
961	i < MB_NUM_ORDERS(ac->ac_sb); i++) {
962	grp = ext4_mb_find_good_group_avg_frag_lists(ac, order: i);
963	if (grp) {
964	*group = grp->bb_group;
965	ac->ac_flags |= EXT4_MB_CR_GOAL_LEN_FAST_OPTIMIZED;
966	return;
967	}
968	}
969
970	/*
971	* CR_BEST_AVAIL_LEN works based on the concept that we have
972	* a larger normalized goal len request which can be trimmed to
973	* a smaller goal len such that it can still satisfy original
974	* request len. However, allocation request for non-regular
975	* files never gets normalized.
976	* See function ext4_mb_normalize_request() (EXT4_MB_HINT_DATA).
977	*/
978	if (ac->ac_flags & EXT4_MB_HINT_DATA)
979	*new_cr = CR_BEST_AVAIL_LEN;
980	else
981	*new_cr = CR_GOAL_LEN_SLOW;
982	}
983
984	/*
985	* We couldn't find a group in CR_GOAL_LEN_FAST so try to find the highest free fragment
986	* order we have and proactively trim the goal request length to that order to
987	* find a suitable group faster.
988	*
989	* This optimizes allocation speed at the cost of slightly reduced
990	* preallocations. However, we make sure that we don't trim the request too
991	* much and fall to CR_GOAL_LEN_SLOW in that case.
992	*/
993	static void ext4_mb_choose_next_group_best_avail(struct ext4_allocation_context *ac,
994	enum criteria *new_cr, ext4_group_t *group)
995	{
996	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
997	struct ext4_group_info *grp = NULL;
998	int i, order, min_order;
999	unsigned long num_stripe_clusters = 0;
1000
1001	if (unlikely(ac->ac_flags & EXT4_MB_CR_BEST_AVAIL_LEN_OPTIMIZED)) {
1002	if (sbi->s_mb_stats)
1003	atomic_inc(v: &sbi->s_bal_best_avail_bad_suggestions);
1004	}
1005
1006	/*
1007	* mb_avg_fragment_size_order() returns order in a way that makes
1008	* retrieving back the length using (1 << order) inaccurate. Hence, use
1009	* fls() instead since we need to know the actual length while modifying
1010	* goal length.
1011	*/
1012	order = fls(x: ac->ac_g_ex.fe_len) - 1;
1013	if (WARN_ON_ONCE(order - 1 > MB_NUM_ORDERS(ac->ac_sb)))
1014	order = MB_NUM_ORDERS(ac->ac_sb);
1015	min_order = order - sbi->s_mb_best_avail_max_trim_order;
1016	if (min_order < 0)
1017	min_order = 0;
1018
1019	if (sbi->s_stripe > 0) {
1020	/*
1021	* We are assuming that stripe size is always a multiple of
1022	* cluster ratio otherwise __ext4_fill_super exists early.
1023	*/
1024	num_stripe_clusters = EXT4_NUM_B2C(sbi, sbi->s_stripe);
1025	if (1 << min_order < num_stripe_clusters)
1026	/*
1027	* We consider 1 order less because later we round
1028	* up the goal len to num_stripe_clusters
1029	*/
1030	min_order = fls(x: num_stripe_clusters) - 1;
1031	}
1032
1033	if (1 << min_order < ac->ac_o_ex.fe_len)
1034	min_order = fls(x: ac->ac_o_ex.fe_len);
1035
1036	for (i = order; i >= min_order; i--) {
1037	int frag_order;
1038	/*
1039	* Scale down goal len to make sure we find something
1040	* in the free fragments list. Basically, reduce
1041	* preallocations.
1042	*/
1043	ac->ac_g_ex.fe_len = 1 << i;
1044
1045	if (num_stripe_clusters > 0) {
1046	/*
1047	* Try to round up the adjusted goal length to
1048	* stripe size (in cluster units) multiple for
1049	* efficiency.
1050	*/
1051	ac->ac_g_ex.fe_len = roundup(ac->ac_g_ex.fe_len,
1052	num_stripe_clusters);
1053	}
1054
1055	frag_order = mb_avg_fragment_size_order(sb: ac->ac_sb,
1056	len: ac->ac_g_ex.fe_len);
1057
1058	grp = ext4_mb_find_good_group_avg_frag_lists(ac, order: frag_order);
1059	if (grp) {
1060	*group = grp->bb_group;
1061	ac->ac_flags |= EXT4_MB_CR_BEST_AVAIL_LEN_OPTIMIZED;
1062	return;
1063	}
1064	}
1065
1066	/* Reset goal length to original goal length before falling into CR_GOAL_LEN_SLOW */
1067	ac->ac_g_ex.fe_len = ac->ac_orig_goal_len;
1068	*new_cr = CR_GOAL_LEN_SLOW;
1069	}
1070
1071	static inline int should_optimize_scan(struct ext4_allocation_context *ac)
1072	{
1073	if (unlikely(!test_opt2(ac->ac_sb, MB_OPTIMIZE_SCAN)))
1074	return 0;
1075	if (ac->ac_criteria >= CR_GOAL_LEN_SLOW)
1076	return 0;
1077	if (!ext4_test_inode_flag(inode: ac->ac_inode, bit: EXT4_INODE_EXTENTS))
1078	return 0;
1079	return 1;
1080	}
1081
1082	/*
1083	* Return next linear group for allocation.
1084	*/
1085	static ext4_group_t
1086	next_linear_group(ext4_group_t group, ext4_group_t ngroups)
1087	{
1088	/*
1089	* Artificially restricted ngroups for non-extent
1090	* files makes group > ngroups possible on first loop.
1091	*/
1092	return group + 1 >= ngroups ? 0 : group + 1;
1093	}
1094
1095	/*
1096	* ext4_mb_choose_next_group: choose next group for allocation.
1097	*
1098	* @ac Allocation Context
1099	* @new_cr This is an output parameter. If the there is no good group
1100	* available at current CR level, this field is updated to indicate
1101	* the new cr level that should be used.
1102	* @group This is an input / output parameter. As an input it indicates the
1103	* next group that the allocator intends to use for allocation. As
1104	* output, this field indicates the next group that should be used as
1105	* determined by the optimization functions.
1106	* @ngroups Total number of groups
1107	*/
1108	static void ext4_mb_choose_next_group(struct ext4_allocation_context *ac,
1109	enum criteria *new_cr, ext4_group_t *group, ext4_group_t ngroups)
1110	{
1111	*new_cr = ac->ac_criteria;
1112
1113	if (!should_optimize_scan(ac)) {
1114	*group = next_linear_group(group: *group, ngroups);
1115	return;
1116	}
1117
1118	/*
1119	* Optimized scanning can return non adjacent groups which can cause
1120	* seek overhead for rotational disks. So try few linear groups before
1121	* trying optimized scan.
1122	*/
1123	if (ac->ac_groups_linear_remaining) {
1124	*group = next_linear_group(group: *group, ngroups);
1125	ac->ac_groups_linear_remaining--;
1126	return;
1127	}
1128
1129	if (*new_cr == CR_POWER2_ALIGNED) {
1130	ext4_mb_choose_next_group_p2_aligned(ac, new_cr, group);
1131	} else if (*new_cr == CR_GOAL_LEN_FAST) {
1132	ext4_mb_choose_next_group_goal_fast(ac, new_cr, group);
1133	} else if (*new_cr == CR_BEST_AVAIL_LEN) {
1134	ext4_mb_choose_next_group_best_avail(ac, new_cr, group);
1135	} else {
1136	/*
1137	* TODO: For CR_GOAL_LEN_SLOW, we can arrange groups in an
1138	* rb tree sorted by bb_free. But until that happens, we should
1139	* never come here.
1140	*/
1141	WARN_ON(1);
1142	}
1143	}
1144
1145	/*
1146	* Cache the order of the largest free extent we have available in this block
1147	* group.
1148	*/
1149	static void
1150	mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
1151	{
1152	struct ext4_sb_info *sbi = EXT4_SB(sb);
1153	int i;
1154
1155	for (i = MB_NUM_ORDERS(sb) - 1; i >= 0; i--)
1156	if (grp->bb_counters[i] > 0)
1157	break;
1158	/* No need to move between order lists? */
1159	if (!test_opt2(sb, MB_OPTIMIZE_SCAN) ||
1160	i == grp->bb_largest_free_order) {
1161	grp->bb_largest_free_order = i;
1162	return;
1163	}
1164
1165	if (grp->bb_largest_free_order >= 0) {
1166	write_lock(&sbi->s_mb_largest_free_orders_locks[
1167	grp->bb_largest_free_order]);
1168	list_del_init(entry: &grp->bb_largest_free_order_node);
1169	write_unlock(&sbi->s_mb_largest_free_orders_locks[
1170	grp->bb_largest_free_order]);
1171	}
1172	grp->bb_largest_free_order = i;
1173	if (grp->bb_largest_free_order >= 0 && grp->bb_free) {
1174	write_lock(&sbi->s_mb_largest_free_orders_locks[
1175	grp->bb_largest_free_order]);
1176	list_add_tail(new: &grp->bb_largest_free_order_node,
1177	head: &sbi->s_mb_largest_free_orders[grp->bb_largest_free_order]);
1178	write_unlock(&sbi->s_mb_largest_free_orders_locks[
1179	grp->bb_largest_free_order]);
1180	}
1181	}
1182
1183	static noinline_for_stack
1184	void ext4_mb_generate_buddy(struct super_block *sb,
1185	void *buddy, void *bitmap, ext4_group_t group,
1186	struct ext4_group_info *grp)
1187	{
1188	struct ext4_sb_info *sbi = EXT4_SB(sb);
1189	ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
1190	ext4_grpblk_t i = 0;
1191	ext4_grpblk_t first;
1192	ext4_grpblk_t len;
1193	unsigned free = 0;
1194	unsigned fragments = 0;
1195	unsigned long long period = get_cycles();
1196
1197	/* initialize buddy from bitmap which is aggregation
1198	* of on-disk bitmap and preallocations */
1199	i = mb_find_next_zero_bit(addr: bitmap, max, start: 0);
1200	grp->bb_first_free = i;
1201	while (i < max) {
1202	fragments++;
1203	first = i;
1204	i = mb_find_next_bit(addr: bitmap, max, start: i);
1205	len = i - first;
1206	free += len;
1207	if (len > 1)
1208	ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
1209	else
1210	grp->bb_counters[0]++;
1211	if (i < max)
1212	i = mb_find_next_zero_bit(addr: bitmap, max, start: i);
1213	}
1214	grp->bb_fragments = fragments;
1215
1216	if (free != grp->bb_free) {
1217	ext4_grp_locked_error(sb, group, 0, 0,
1218	"block bitmap and bg descriptor "
1219	"inconsistent: %u vs %u free clusters",
1220	free, grp->bb_free);
1221	/*
1222	* If we intend to continue, we consider group descriptor
1223	* corrupt and update bb_free using bitmap value
1224	*/
1225	grp->bb_free = free;
1226	ext4_mark_group_bitmap_corrupted(sb, block_group: group,
1227	EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1228	}
1229	mb_set_largest_free_order(sb, grp);
1230	mb_update_avg_fragment_size(sb, grp);
1231
1232	clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, addr: &(grp->bb_state));
1233
1234	period = get_cycles() - period;
1235	atomic_inc(v: &sbi->s_mb_buddies_generated);
1236	atomic64_add(i: period, v: &sbi->s_mb_generation_time);
1237	}
1238
1239	static void mb_regenerate_buddy(struct ext4_buddy *e4b)
1240	{
1241	int count;
1242	int order = 1;
1243	void *buddy;
1244
1245	while ((buddy = mb_find_buddy(e4b, order: order++, max: &count)))
1246	mb_set_bits(bm: buddy, cur: 0, len: count);
1247
1248	e4b->bd_info->bb_fragments = 0;
1249	memset(e4b->bd_info->bb_counters, 0,
1250	sizeof(*e4b->bd_info->bb_counters) *
1251	(e4b->bd_sb->s_blocksize_bits + 2));
1252
1253	ext4_mb_generate_buddy(sb: e4b->bd_sb, buddy: e4b->bd_buddy,
1254	bitmap: e4b->bd_bitmap, group: e4b->bd_group, grp: e4b->bd_info);
1255	}
1256
1257	/* The buddy information is attached the buddy cache inode
1258	* for convenience. The information regarding each group
1259	* is loaded via ext4_mb_load_buddy. The information involve
1260	* block bitmap and buddy information. The information are
1261	* stored in the inode as
1262	*
1263	* { page }
1264	* [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]...
1265	*
1266	*
1267	* one block each for bitmap and buddy information.
1268	* So for each group we take up 2 blocks. A page can
1269	* contain blocks_per_page (PAGE_SIZE / blocksize) blocks.
1270	* So it can have information regarding groups_per_page which
1271	* is blocks_per_page/2
1272	*
1273	* Locking note: This routine takes the block group lock of all groups
1274	* for this page; do not hold this lock when calling this routine!
1275	*/
1276
1277	static int ext4_mb_init_cache(struct folio *folio, char *incore, gfp_t gfp)
1278	{
1279	ext4_group_t ngroups;
1280	unsigned int blocksize;
1281	int blocks_per_page;
1282	int groups_per_page;
1283	int err = 0;
1284	int i;
1285	ext4_group_t first_group, group;
1286	int first_block;
1287	struct super_block *sb;
1288	struct buffer_head *bhs;
1289	struct buffer_head **bh = NULL;
1290	struct inode *inode;
1291	char *data;
1292	char *bitmap;
1293	struct ext4_group_info *grinfo;
1294
1295	inode = folio->mapping->host;
1296	sb = inode->i_sb;
1297	ngroups = ext4_get_groups_count(sb);
1298	blocksize = i_blocksize(node: inode);
1299	blocks_per_page = PAGE_SIZE / blocksize;
1300
1301	mb_debug(sb, "init folio %lu\n", folio->index);
1302
1303	groups_per_page = blocks_per_page >> 1;
1304	if (groups_per_page == 0)
1305	groups_per_page = 1;
1306
1307	/* allocate buffer_heads to read bitmaps */
1308	if (groups_per_page > 1) {
1309	i = sizeof(struct buffer_head *) * groups_per_page;
1310	bh = kzalloc(i, gfp);
1311	if (bh == NULL)
1312	return -ENOMEM;
1313	} else
1314	bh = &bhs;
1315
1316	first_group = folio->index * blocks_per_page / 2;
1317
1318	/* read all groups the folio covers into the cache */
1319	for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
1320	if (group >= ngroups)
1321	break;
1322
1323	grinfo = ext4_get_group_info(sb, group);
1324	if (!grinfo)
1325	continue;
1326	/*
1327	* If page is uptodate then we came here after online resize
1328	* which added some new uninitialized group info structs, so
1329	* we must skip all initialized uptodate buddies on the folio,
1330	* which may be currently in use by an allocating task.
1331	*/
1332	if (folio_test_uptodate(folio) &&
1333	!EXT4_MB_GRP_NEED_INIT(grinfo)) {
1334	bh[i] = NULL;
1335	continue;
1336	}
1337	bh[i] = ext4_read_block_bitmap_nowait(sb, block_group: group, ignore_locked: false);
1338	if (IS_ERR(ptr: bh[i])) {
1339	err = PTR_ERR(ptr: bh[i]);
1340	bh[i] = NULL;
1341	goto out;
1342	}
1343	mb_debug(sb, "read bitmap for group %u\n", group);
1344	}
1345
1346	/* wait for I/O completion */
1347	for (i = 0, group = first_group; i < groups_per_page; i++, group++) {
1348	int err2;
1349
1350	if (!bh[i])
1351	continue;
1352	err2 = ext4_wait_block_bitmap(sb, block_group: group, bh: bh[i]);
1353	if (!err)
1354	err = err2;
1355	}
1356
1357	first_block = folio->index * blocks_per_page;
1358	for (i = 0; i < blocks_per_page; i++) {
1359	group = (first_block + i) >> 1;
1360	if (group >= ngroups)
1361	break;
1362
1363	if (!bh[group - first_group])
1364	/* skip initialized uptodate buddy */
1365	continue;
1366
1367	if (!buffer_verified(bh: bh[group - first_group]))
1368	/* Skip faulty bitmaps */
1369	continue;
1370	err = 0;
1371
1372	/*
1373	* data carry information regarding this
1374	* particular group in the format specified
1375	* above
1376	*
1377	*/
1378	data = folio_address(folio) + (i * blocksize);
1379	bitmap = bh[group - first_group]->b_data;
1380
1381	/*
1382	* We place the buddy block and bitmap block
1383	* close together
1384	*/
1385	grinfo = ext4_get_group_info(sb, group);
1386	if (!grinfo) {
1387	err = -EFSCORRUPTED;
1388	goto out;
1389	}
1390	if ((first_block + i) & 1) {
1391	/* this is block of buddy */
1392	BUG_ON(incore == NULL);
1393	mb_debug(sb, "put buddy for group %u in folio %lu/%x\n",
1394	group, folio->index, i * blocksize);
1395	trace_ext4_mb_buddy_bitmap_load(sb, group);
1396	grinfo->bb_fragments = 0;
1397	memset(grinfo->bb_counters, 0,
1398	sizeof(*grinfo->bb_counters) *
1399	(MB_NUM_ORDERS(sb)));
1400	/*
1401	* incore got set to the group block bitmap below
1402	*/
1403	ext4_lock_group(sb, group);
1404	/* init the buddy */
1405	memset(data, 0xff, blocksize);
1406	ext4_mb_generate_buddy(sb, buddy: data, bitmap: incore, group, grp: grinfo);
1407	ext4_unlock_group(sb, group);
1408	incore = NULL;
1409	} else {
1410	/* this is block of bitmap */
1411	BUG_ON(incore != NULL);
1412	mb_debug(sb, "put bitmap for group %u in folio %lu/%x\n",
1413	group, folio->index, i * blocksize);
1414	trace_ext4_mb_bitmap_load(sb, group);
1415
1416	/* see comments in ext4_mb_put_pa() */
1417	ext4_lock_group(sb, group);
1418	memcpy(data, bitmap, blocksize);
1419
1420	/* mark all preallocated blks used in in-core bitmap */
1421	ext4_mb_generate_from_pa(sb, bitmap: data, group);
1422	WARN_ON_ONCE(!RB_EMPTY_ROOT(&grinfo->bb_free_root));
1423	ext4_unlock_group(sb, group);
1424
1425	/* set incore so that the buddy information can be
1426	* generated using this
1427	*/
1428	incore = data;
1429	}
1430	}
1431	folio_mark_uptodate(folio);
1432
1433	out:
1434	if (bh) {
1435	for (i = 0; i < groups_per_page; i++)
1436	brelse(bh: bh[i]);
1437	if (bh != &bhs)
1438	kfree(objp: bh);
1439	}
1440	return err;
1441	}
1442
1443	/*
1444	* Lock the buddy and bitmap pages. This make sure other parallel init_group
1445	* on the same buddy page doesn't happen whild holding the buddy page lock.
1446	* Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap
1447	* are on the same page e4b->bd_buddy_folio is NULL and return value is 0.
1448	*/
1449	static int ext4_mb_get_buddy_page_lock(struct super_block *sb,
1450	ext4_group_t group, struct ext4_buddy *e4b, gfp_t gfp)
1451	{
1452	struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
1453	int block, pnum, poff;
1454	int blocks_per_page;
1455	struct folio *folio;
1456
1457	e4b->bd_buddy_folio = NULL;
1458	e4b->bd_bitmap_folio = NULL;
1459
1460	blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1461	/*
1462	* the buddy cache inode stores the block bitmap
1463	* and buddy information in consecutive blocks.
1464	* So for each group we need two blocks.
1465	*/
1466	block = group * 2;
1467	pnum = block / blocks_per_page;
1468	poff = block % blocks_per_page;
1469	folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum,
1470	FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp);
1471	if (IS_ERR(ptr: folio))
1472	return PTR_ERR(ptr: folio);
1473	BUG_ON(folio->mapping != inode->i_mapping);
1474	e4b->bd_bitmap_folio = folio;
1475	e4b->bd_bitmap = folio_address(folio) + (poff * sb->s_blocksize);
1476
1477	if (blocks_per_page >= 2) {
1478	/* buddy and bitmap are on the same page */
1479	return 0;
1480	}
1481
1482	/* blocks_per_page == 1, hence we need another page for the buddy */
1483	folio = __filemap_get_folio(mapping: inode->i_mapping, index: block + 1,
1484	FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp);
1485	if (IS_ERR(ptr: folio))
1486	return PTR_ERR(ptr: folio);
1487	BUG_ON(folio->mapping != inode->i_mapping);
1488	e4b->bd_buddy_folio = folio;
1489	return 0;
1490	}
1491
1492	static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b)
1493	{
1494	if (e4b->bd_bitmap_folio) {
1495	folio_unlock(folio: e4b->bd_bitmap_folio);
1496	folio_put(folio: e4b->bd_bitmap_folio);
1497	}
1498	if (e4b->bd_buddy_folio) {
1499	folio_unlock(folio: e4b->bd_buddy_folio);
1500	folio_put(folio: e4b->bd_buddy_folio);
1501	}
1502	}
1503
1504	/*
1505	* Locking note: This routine calls ext4_mb_init_cache(), which takes the
1506	* block group lock of all groups for this page; do not hold the BG lock when
1507	* calling this routine!
1508	*/
1509	static noinline_for_stack
1510	int ext4_mb_init_group(struct super_block *sb, ext4_group_t group, gfp_t gfp)
1511	{
1512
1513	struct ext4_group_info *this_grp;
1514	struct ext4_buddy e4b;
1515	struct folio *folio;
1516	int ret = 0;
1517
1518	might_sleep();
1519	mb_debug(sb, "init group %u\n", group);
1520	this_grp = ext4_get_group_info(sb, group);
1521	if (!this_grp)
1522	return -EFSCORRUPTED;
1523
1524	/*
1525	* This ensures that we don't reinit the buddy cache
1526	* page which map to the group from which we are already
1527	* allocating. If we are looking at the buddy cache we would
1528	* have taken a reference using ext4_mb_load_buddy and that
1529	* would have pinned buddy page to page cache.
1530	* The call to ext4_mb_get_buddy_page_lock will mark the
1531	* page accessed.
1532	*/
1533	ret = ext4_mb_get_buddy_page_lock(sb, group, e4b: &e4b, gfp);
1534	if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) {
1535	/*
1536	* somebody initialized the group
1537	* return without doing anything
1538	*/
1539	goto err;
1540	}
1541
1542	folio = e4b.bd_bitmap_folio;
1543	ret = ext4_mb_init_cache(folio, NULL, gfp);
1544	if (ret)
1545	goto err;
1546	if (!folio_test_uptodate(folio)) {
1547	ret = -EIO;
1548	goto err;
1549	}
1550
1551	if (e4b.bd_buddy_folio == NULL) {
1552	/*
1553	* If both the bitmap and buddy are in
1554	* the same page we don't need to force
1555	* init the buddy
1556	*/
1557	ret = 0;
1558	goto err;
1559	}
1560	/* init buddy cache */
1561	folio = e4b.bd_buddy_folio;
1562	ret = ext4_mb_init_cache(folio, incore: e4b.bd_bitmap, gfp);
1563	if (ret)
1564	goto err;
1565	if (!folio_test_uptodate(folio)) {
1566	ret = -EIO;
1567	goto err;
1568	}
1569	err:
1570	ext4_mb_put_buddy_page_lock(e4b: &e4b);
1571	return ret;
1572	}
1573
1574	/*
1575	* Locking note: This routine calls ext4_mb_init_cache(), which takes the
1576	* block group lock of all groups for this page; do not hold the BG lock when
1577	* calling this routine!
1578	*/
1579	static noinline_for_stack int
1580	ext4_mb_load_buddy_gfp(struct super_block *sb, ext4_group_t group,
1581	struct ext4_buddy *e4b, gfp_t gfp)
1582	{
1583	int blocks_per_page;
1584	int block;
1585	int pnum;
1586	int poff;
1587	struct folio *folio;
1588	int ret;
1589	struct ext4_group_info *grp;
1590	struct ext4_sb_info *sbi = EXT4_SB(sb);
1591	struct inode *inode = sbi->s_buddy_cache;
1592
1593	might_sleep();
1594	mb_debug(sb, "load group %u\n", group);
1595
1596	blocks_per_page = PAGE_SIZE / sb->s_blocksize;
1597	grp = ext4_get_group_info(sb, group);
1598	if (!grp)
1599	return -EFSCORRUPTED;
1600
1601	e4b->bd_blkbits = sb->s_blocksize_bits;
1602	e4b->bd_info = grp;
1603	e4b->bd_sb = sb;
1604	e4b->bd_group = group;
1605	e4b->bd_buddy_folio = NULL;
1606	e4b->bd_bitmap_folio = NULL;
1607
1608	if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
1609	/*
1610	* we need full data about the group
1611	* to make a good selection
1612	*/
1613	ret = ext4_mb_init_group(sb, group, gfp);
1614	if (ret)
1615	return ret;
1616	}
1617
1618	/*
1619	* the buddy cache inode stores the block bitmap
1620	* and buddy information in consecutive blocks.
1621	* So for each group we need two blocks.
1622	*/
1623	block = group * 2;
1624	pnum = block / blocks_per_page;
1625	poff = block % blocks_per_page;
1626
1627	/* Avoid locking the folio in the fast path ... */
1628	folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum, FGP_ACCESSED, gfp: 0);
1629	if (IS_ERR(ptr: folio) || !folio_test_uptodate(folio)) {
1630	if (!IS_ERR(ptr: folio))
1631	/*
1632	* drop the folio reference and try
1633	* to get the folio with lock. If we
1634	* are not uptodate that implies
1635	* somebody just created the folio but
1636	* is yet to initialize it. So
1637	* wait for it to initialize.
1638	*/
1639	folio_put(folio);
1640	folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum,
1641	FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp);
1642	if (!IS_ERR(ptr: folio)) {
1643	if (WARN_RATELIMIT(folio->mapping != inode->i_mapping,
1644	"ext4: bitmap's mapping != inode->i_mapping\n")) {
1645	/* should never happen */
1646	folio_unlock(folio);
1647	ret = -EINVAL;
1648	goto err;
1649	}
1650	if (!folio_test_uptodate(folio)) {
1651	ret = ext4_mb_init_cache(folio, NULL, gfp);
1652	if (ret) {
1653	folio_unlock(folio);
1654	goto err;
1655	}
1656	mb_cmp_bitmaps(e4b, bitmap: folio_address(folio) +
1657	(poff * sb->s_blocksize));
1658	}
1659	folio_unlock(folio);
1660	}
1661	}
1662	if (IS_ERR(ptr: folio)) {
1663	ret = PTR_ERR(ptr: folio);
1664	goto err;
1665	}
1666	if (!folio_test_uptodate(folio)) {
1667	ret = -EIO;
1668	goto err;
1669	}
1670
1671	/* Folios marked accessed already */
1672	e4b->bd_bitmap_folio = folio;
1673	e4b->bd_bitmap = folio_address(folio) + (poff * sb->s_blocksize);
1674
1675	block++;
1676	pnum = block / blocks_per_page;
1677	poff = block % blocks_per_page;
1678
1679	folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum, FGP_ACCESSED, gfp: 0);
1680	if (IS_ERR(ptr: folio) || !folio_test_uptodate(folio)) {
1681	if (!IS_ERR(ptr: folio))
1682	folio_put(folio);
1683	folio = __filemap_get_folio(mapping: inode->i_mapping, index: pnum,
1684	FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp);
1685	if (!IS_ERR(ptr: folio)) {
1686	if (WARN_RATELIMIT(folio->mapping != inode->i_mapping,
1687	"ext4: buddy bitmap's mapping != inode->i_mapping\n")) {
1688	/* should never happen */
1689	folio_unlock(folio);
1690	ret = -EINVAL;
1691	goto err;
1692	}
1693	if (!folio_test_uptodate(folio)) {
1694	ret = ext4_mb_init_cache(folio, incore: e4b->bd_bitmap,
1695	gfp);
1696	if (ret) {
1697	folio_unlock(folio);
1698	goto err;
1699	}
1700	}
1701	folio_unlock(folio);
1702	}
1703	}
1704	if (IS_ERR(ptr: folio)) {
1705	ret = PTR_ERR(ptr: folio);
1706	goto err;
1707	}
1708	if (!folio_test_uptodate(folio)) {
1709	ret = -EIO;
1710	goto err;
1711	}
1712
1713	/* Folios marked accessed already */
1714	e4b->bd_buddy_folio = folio;
1715	e4b->bd_buddy = folio_address(folio) + (poff * sb->s_blocksize);
1716
1717	return 0;
1718
1719	err:
1720	if (!IS_ERR_OR_NULL(ptr: folio))
1721	folio_put(folio);
1722	if (e4b->bd_bitmap_folio)
1723	folio_put(folio: e4b->bd_bitmap_folio);
1724
1725	e4b->bd_buddy = NULL;
1726	e4b->bd_bitmap = NULL;
1727	return ret;
1728	}
1729
1730	static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1731	struct ext4_buddy *e4b)
1732	{
1733	return ext4_mb_load_buddy_gfp(sb, group, e4b, GFP_NOFS);
1734	}
1735
1736	static void ext4_mb_unload_buddy(struct ext4_buddy *e4b)
1737	{
1738	if (e4b->bd_bitmap_folio)
1739	folio_put(folio: e4b->bd_bitmap_folio);
1740	if (e4b->bd_buddy_folio)
1741	folio_put(folio: e4b->bd_buddy_folio);
1742	}
1743
1744
1745	static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1746	{
1747	int order = 1, max;
1748	void *bb;
1749
1750	BUG_ON(e4b->bd_bitmap == e4b->bd_buddy);
1751	BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1752
1753	while (order <= e4b->bd_blkbits + 1) {
1754	bb = mb_find_buddy(e4b, order, max: &max);
1755	if (!mb_test_bit(bit: block >> order, addr: bb)) {
1756	/* this block is part of buddy of order 'order' */
1757	return order;
1758	}
1759	order++;
1760	}
1761	return 0;
1762	}
1763
1764	static void mb_clear_bits(void *bm, int cur, int len)
1765	{
1766	__u32 *addr;
1767
1768	len = cur + len;
1769	while (cur < len) {
1770	if ((cur & 31) == 0 && (len - cur) >= 32) {
1771	/* fast path: clear whole word at once */
1772	addr = bm + (cur >> 3);
1773	*addr = 0;
1774	cur += 32;
1775	continue;
1776	}
1777	mb_clear_bit(bit: cur, addr: bm);
1778	cur++;
1779	}
1780	}
1781
1782	/* clear bits in given range
1783	* will return first found zero bit if any, -1 otherwise
1784	*/
1785	static int mb_test_and_clear_bits(void *bm, int cur, int len)
1786	{
1787	__u32 *addr;
1788	int zero_bit = -1;
1789
1790	len = cur + len;
1791	while (cur < len) {
1792	if ((cur & 31) == 0 && (len - cur) >= 32) {
1793	/* fast path: clear whole word at once */
1794	addr = bm + (cur >> 3);
1795	if (*addr != (__u32)(-1) && zero_bit == -1)
1796	zero_bit = cur + mb_find_next_zero_bit(addr, max: 32, start: 0);
1797	*addr = 0;
1798	cur += 32;
1799	continue;
1800	}
1801	if (!mb_test_and_clear_bit(bit: cur, addr: bm) && zero_bit == -1)
1802	zero_bit = cur;
1803	cur++;
1804	}
1805
1806	return zero_bit;
1807	}
1808
1809	void mb_set_bits(void *bm, int cur, int len)
1810	{
1811	__u32 *addr;
1812
1813	len = cur + len;
1814	while (cur < len) {
1815	if ((cur & 31) == 0 && (len - cur) >= 32) {
1816	/* fast path: set whole word at once */
1817	addr = bm + (cur >> 3);
1818	*addr = 0xffffffff;
1819	cur += 32;
1820	continue;
1821	}
1822	mb_set_bit(bit: cur, addr: bm);
1823	cur++;
1824	}
1825	}
1826
1827	static inline int mb_buddy_adjust_border(int* bit, void* bitmap, int side)
1828	{
1829	if (mb_test_bit(bit: *bit + side, addr: bitmap)) {
1830	mb_clear_bit(bit: *bit, addr: bitmap);
1831	(*bit) -= side;
1832	return 1;
1833	}
1834	else {
1835	(*bit) += side;
1836	mb_set_bit(bit: *bit, addr: bitmap);
1837	return -1;
1838	}
1839	}
1840
1841	static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first, int last)
1842	{
1843	int max;
1844	int order = 1;
1845	void *buddy = mb_find_buddy(e4b, order, max: &max);
1846
1847	while (buddy) {
1848	void *buddy2;
1849
1850	/* Bits in range [first; last] are known to be set since
1851	* corresponding blocks were allocated. Bits in range
1852	* (first; last) will stay set because they form buddies on
1853	* upper layer. We just deal with borders if they don't
1854	* align with upper layer and then go up.
1855	* Releasing entire group is all about clearing
1856	* single bit of highest order buddy.
1857	*/
1858
1859	/* Example:
1860	* ---------------------------------
1861	* | 1 | 1 | 1 | 1 |
1862	* ---------------------------------
1863	* | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
1864	* ---------------------------------
1865	* 0 1 2 3 4 5 6 7
1866	* \_____________________/
1867	*
1868	* Neither [1] nor [6] is aligned to above layer.
1869	* Left neighbour [0] is free, so mark it busy,
1870	* decrease bb_counters and extend range to
1871	* [0; 6]
1872	* Right neighbour [7] is busy. It can't be coaleasced with [6], so
1873	* mark [6] free, increase bb_counters and shrink range to
1874	* [0; 5].
1875	* Then shift range to [0; 2], go up and do the same.
1876	*/
1877
1878
1879	if (first & 1)
1880	e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(bit: &first, bitmap: buddy, side: -1);
1881	if (!(last & 1))
1882	e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(bit: &last, bitmap: buddy, side: 1);
1883	if (first > last)
1884	break;
1885	order++;
1886
1887	buddy2 = mb_find_buddy(e4b, order, max: &max);
1888	if (!buddy2) {
1889	mb_clear_bits(bm: buddy, cur: first, len: last - first + 1);
1890	e4b->bd_info->bb_counters[order - 1] += last - first + 1;
1891	break;
1892	}
1893	first >>= 1;
1894	last >>= 1;
1895	buddy = buddy2;
1896	}
1897	}
1898
1899	static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1900	int first, int count)
1901	{
1902	int left_is_free = 0;
1903	int right_is_free = 0;
1904	int block;
1905	int last = first + count - 1;
1906	struct super_block *sb = e4b->bd_sb;
1907
1908	if (WARN_ON(count == 0))
1909	return;
1910	BUG_ON(last >= (sb->s_blocksize << 3));
1911	assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group));
1912	/* Don't bother if the block group is corrupt. */
1913	if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
1914	return;
1915
1916	mb_check_buddy(e4b);
1917	mb_free_blocks_double(inode, e4b, first, count);
1918
1919	/* access memory sequentially: check left neighbour,
1920	* clear range and then check right neighbour
1921	*/
1922	if (first != 0)
1923	left_is_free = !mb_test_bit(bit: first - 1, addr: e4b->bd_bitmap);
1924	block = mb_test_and_clear_bits(bm: e4b->bd_bitmap, cur: first, len: count);
1925	if (last + 1 < EXT4_SB(sb)->s_mb_maxs[0])
1926	right_is_free = !mb_test_bit(bit: last + 1, addr: e4b->bd_bitmap);
1927
1928	if (unlikely(block != -1)) {
1929	struct ext4_sb_info *sbi = EXT4_SB(sb);
1930	ext4_fsblk_t blocknr;
1931
1932	/*
1933	* Fastcommit replay can free already freed blocks which
1934	* corrupts allocation info. Regenerate it.
1935	*/
1936	if (sbi->s_mount_state & EXT4_FC_REPLAY) {
1937	mb_regenerate_buddy(e4b);
1938	goto check;
1939	}
1940
1941	blocknr = ext4_group_first_block_no(sb, group_no: e4b->bd_group);
1942	blocknr += EXT4_C2B(sbi, block);
1943	ext4_mark_group_bitmap_corrupted(sb, block_group: e4b->bd_group,
1944	EXT4_GROUP_INFO_BBITMAP_CORRUPT);
1945	ext4_grp_locked_error(sb, e4b->bd_group,
1946	inode ? inode->i_ino : 0, blocknr,
1947	"freeing already freed block (bit %u); block bitmap corrupt.",
1948	block);
1949	return;
1950	}
1951
1952	this_cpu_inc(discard_pa_seq);
1953	e4b->bd_info->bb_free += count;
1954	if (first < e4b->bd_info->bb_first_free)
1955	e4b->bd_info->bb_first_free = first;
1956
1957	/* let's maintain fragments counter */
1958	if (left_is_free && right_is_free)
1959	e4b->bd_info->bb_fragments--;
1960	else if (!left_is_free && !right_is_free)
1961	e4b->bd_info->bb_fragments++;
1962
1963	/* buddy[0] == bd_bitmap is a special case, so handle
1964	* it right away and let mb_buddy_mark_free stay free of
1965	* zero order checks.
1966	* Check if neighbours are to be coaleasced,
1967	* adjust bitmap bb_counters and borders appropriately.
1968	*/
1969	if (first & 1) {
1970	first += !left_is_free;
1971	e4b->bd_info->bb_counters[0] += left_is_free ? -1 : 1;
1972	}
1973	if (!(last & 1)) {
1974	last -= !right_is_free;
1975	e4b->bd_info->bb_counters[0] += right_is_free ? -1 : 1;
1976	}
1977
1978	if (first <= last)
1979	mb_buddy_mark_free(e4b, first: first >> 1, last: last >> 1);
1980
1981	mb_set_largest_free_order(sb, grp: e4b->bd_info);
1982	mb_update_avg_fragment_size(sb, grp: e4b->bd_info);
1983	check:
1984	mb_check_buddy(e4b);
1985	}
1986
1987	static int mb_find_extent(struct ext4_buddy *e4b, int block,
1988	int needed, struct ext4_free_extent *ex)
1989	{
1990	int max, order, next;
1991	void *buddy;
1992
1993	assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
1994	BUG_ON(ex == NULL);
1995
1996	buddy = mb_find_buddy(e4b, order: 0, max: &max);
1997	BUG_ON(buddy == NULL);
1998	BUG_ON(block >= max);
1999	if (mb_test_bit(bit: block, addr: buddy)) {
2000	ex->fe_len = 0;
2001	ex->fe_start = 0;
2002	ex->fe_group = 0;
2003	return 0;
2004	}
2005
2006	/* find actual order */
2007	order = mb_find_order_for_block(e4b, block);
2008
2009	ex->fe_len = (1 << order) - (block & ((1 << order) - 1));
2010	ex->fe_start = block;
2011	ex->fe_group = e4b->bd_group;
2012
2013	block = block >> order;
2014
2015	while (needed > ex->fe_len &&
2016	mb_find_buddy(e4b, order, max: &max)) {
2017
2018	if (block + 1 >= max)
2019	break;
2020
2021	next = (block + 1) * (1 << order);
2022	if (mb_test_bit(bit: next, addr: e4b->bd_bitmap))
2023	break;
2024
2025	order = mb_find_order_for_block(e4b, block: next);
2026
2027	block = next >> order;
2028	ex->fe_len += 1 << order;
2029	}
2030
2031	if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) {
2032	/* Should never happen! (but apparently sometimes does?!?) */
2033	WARN_ON(1);
2034	ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0,
2035	"corruption or bug in mb_find_extent "
2036	"block=%d, order=%d needed=%d ex=%u/%d/%d@%u",
2037	block, order, needed, ex->fe_group, ex->fe_start,
2038	ex->fe_len, ex->fe_logical);
2039	ex->fe_len = 0;
2040	ex->fe_start = 0;
2041	ex->fe_group = 0;
2042	}
2043	return ex->fe_len;
2044	}
2045
2046	static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
2047	{
2048	int ord;
2049	int mlen = 0;
2050	int max = 0;
2051	int start = ex->fe_start;
2052	int len = ex->fe_len;
2053	unsigned ret = 0;
2054	int len0 = len;
2055	void *buddy;
2056	int ord_start, ord_end;
2057
2058	BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
2059	BUG_ON(e4b->bd_group != ex->fe_group);
2060	assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group));
2061	mb_check_buddy(e4b);
2062	mb_mark_used_double(e4b, first: start, count: len);
2063
2064	this_cpu_inc(discard_pa_seq);
2065	e4b->bd_info->bb_free -= len;
2066	if (e4b->bd_info->bb_first_free == start)
2067	e4b->bd_info->bb_first_free += len;
2068
2069	/* let's maintain fragments counter */
2070	if (start != 0)
2071	mlen = !mb_test_bit(bit: start - 1, addr: e4b->bd_bitmap);
2072	if (start + len < EXT4_SB(sb: e4b->bd_sb)->s_mb_maxs[0])
2073	max = !mb_test_bit(bit: start + len, addr: e4b->bd_bitmap);
2074	if (mlen && max)
2075	e4b->bd_info->bb_fragments++;
2076	else if (!mlen && !max)
2077	e4b->bd_info->bb_fragments--;
2078
2079	/* let's maintain buddy itself */
2080	while (len) {
2081	ord = mb_find_order_for_block(e4b, block: start);
2082
2083	if (((start >> ord) << ord) == start && len >= (1 << ord)) {
2084	/* the whole chunk may be allocated at once! */
2085	mlen = 1 << ord;
2086	buddy = mb_find_buddy(e4b, order: ord, max: &max);
2087	BUG_ON((start >> ord) >= max);
2088	mb_set_bit(bit: start >> ord, addr: buddy);
2089	e4b->bd_info->bb_counters[ord]--;
2090	start += mlen;
2091	len -= mlen;
2092	BUG_ON(len < 0);
2093	continue;
2094	}
2095
2096	/* store for history */
2097	if (ret == 0)
2098	ret = len | (ord << 16);
2099
2100	BUG_ON(ord <= 0);
2101	buddy = mb_find_buddy(e4b, order: ord, max: &max);
2102	mb_set_bit(bit: start >> ord, addr: buddy);
2103	e4b->bd_info->bb_counters[ord]--;
2104
2105	ord_start = (start >> ord) << ord;
2106	ord_end = ord_start + (1 << ord);
2107	/* first chunk */
2108	if (start > ord_start)
2109	ext4_mb_mark_free_simple(sb: e4b->bd_sb, buddy: e4b->bd_buddy,
2110	first: ord_start, len: start - ord_start,
2111	grp: e4b->bd_info);
2112
2113	/* last chunk */
2114	if (start + len < ord_end) {
2115	ext4_mb_mark_free_simple(sb: e4b->bd_sb, buddy: e4b->bd_buddy,
2116	first: start + len,
2117	len: ord_end - (start + len),
2118	grp: e4b->bd_info);
2119	break;
2120	}
2121	len = start + len - ord_end;
2122	start = ord_end;
2123	}
2124	mb_set_largest_free_order(sb: e4b->bd_sb, grp: e4b->bd_info);
2125
2126	mb_update_avg_fragment_size(sb: e4b->bd_sb, grp: e4b->bd_info);
2127	mb_set_bits(bm: e4b->bd_bitmap, cur: ex->fe_start, len: len0);
2128	mb_check_buddy(e4b);
2129
2130	return ret;
2131	}
2132
2133	/*
2134	* Must be called under group lock!
2135	*/
2136	static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
2137	struct ext4_buddy *e4b)
2138	{
2139	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
2140	int ret;
2141
2142	BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
2143	BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2144
2145	ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
2146	ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
2147	ret = mb_mark_used(e4b, ex: &ac->ac_b_ex);
2148
2149	/* preallocation can change ac_b_ex, thus we store actually
2150	* allocated blocks for history */
2151	ac->ac_f_ex = ac->ac_b_ex;
2152
2153	ac->ac_status = AC_STATUS_FOUND;
2154	ac->ac_tail = ret & 0xffff;
2155	ac->ac_buddy = ret >> 16;
2156
2157	/*
2158	* take the page reference. We want the page to be pinned
2159	* so that we don't get a ext4_mb_init_cache_call for this
2160	* group until we update the bitmap. That would mean we
2161	* double allocate blocks. The reference is dropped
2162	* in ext4_mb_release_context
2163	*/
2164	ac->ac_bitmap_folio = e4b->bd_bitmap_folio;
2165	folio_get(folio: ac->ac_bitmap_folio);
2166	ac->ac_buddy_folio = e4b->bd_buddy_folio;
2167	folio_get(folio: ac->ac_buddy_folio);
2168	/* store last allocated for subsequent stream allocation */
2169	if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2170	spin_lock(lock: &sbi->s_md_lock);
2171	sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
2172	sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
2173	spin_unlock(lock: &sbi->s_md_lock);
2174	}
2175	/*
2176	* As we've just preallocated more space than
2177	* user requested originally, we store allocated
2178	* space in a special descriptor.
2179	*/
2180	if (ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
2181	ext4_mb_new_preallocation(ac);
2182
2183	}
2184
2185	static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
2186	struct ext4_buddy *e4b,
2187	int finish_group)
2188	{
2189	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
2190	struct ext4_free_extent *bex = &ac->ac_b_ex;
2191	struct ext4_free_extent *gex = &ac->ac_g_ex;
2192
2193	if (ac->ac_status == AC_STATUS_FOUND)
2194	return;
2195	/*
2196	* We don't want to scan for a whole year
2197	*/
2198	if (ac->ac_found > sbi->s_mb_max_to_scan &&
2199	!(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2200	ac->ac_status = AC_STATUS_BREAK;
2201	return;
2202	}
2203
2204	/*
2205	* Haven't found good chunk so far, let's continue
2206	*/
2207	if (bex->fe_len < gex->fe_len)
2208	return;
2209
2210	if (finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
2211	ext4_mb_use_best_found(ac, e4b);
2212	}
2213
2214	/*
2215	* The routine checks whether found extent is good enough. If it is,
2216	* then the extent gets marked used and flag is set to the context
2217	* to stop scanning. Otherwise, the extent is compared with the
2218	* previous found extent and if new one is better, then it's stored
2219	* in the context. Later, the best found extent will be used, if
2220	* mballoc can't find good enough extent.
2221	*
2222	* The algorithm used is roughly as follows:
2223	*
2224	* * If free extent found is exactly as big as goal, then
2225	* stop the scan and use it immediately
2226	*
2227	* * If free extent found is smaller than goal, then keep retrying
2228	* upto a max of sbi->s_mb_max_to_scan times (default 200). After
2229	* that stop scanning and use whatever we have.
2230	*
2231	* * If free extent found is bigger than goal, then keep retrying
2232	* upto a max of sbi->s_mb_min_to_scan times (default 10) before
2233	* stopping the scan and using the extent.
2234	*
2235	*
2236	* FIXME: real allocation policy is to be designed yet!
2237	*/
2238	static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
2239	struct ext4_free_extent *ex,
2240	struct ext4_buddy *e4b)
2241	{
2242	struct ext4_free_extent *bex = &ac->ac_b_ex;
2243	struct ext4_free_extent *gex = &ac->ac_g_ex;
2244
2245	BUG_ON(ex->fe_len <= 0);
2246	BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
2247	BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb));
2248	BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
2249
2250	ac->ac_found++;
2251	ac->ac_cX_found[ac->ac_criteria]++;
2252
2253	/*
2254	* The special case - take what you catch first
2255	*/
2256	if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2257	*bex = *ex;
2258	ext4_mb_use_best_found(ac, e4b);
2259	return;
2260	}
2261
2262	/*
2263	* Let's check whether the chuck is good enough
2264	*/
2265	if (ex->fe_len == gex->fe_len) {
2266	*bex = *ex;
2267	ext4_mb_use_best_found(ac, e4b);
2268	return;
2269	}
2270
2271	/*
2272	* If this is first found extent, just store it in the context
2273	*/
2274	if (bex->fe_len == 0) {
2275	*bex = *ex;
2276	return;
2277	}
2278
2279	/*
2280	* If new found extent is better, store it in the context
2281	*/
2282	if (bex->fe_len < gex->fe_len) {
2283	/* if the request isn't satisfied, any found extent
2284	* larger than previous best one is better */
2285	if (ex->fe_len > bex->fe_len)
2286	*bex = *ex;
2287	} else if (ex->fe_len > gex->fe_len) {
2288	/* if the request is satisfied, then we try to find
2289	* an extent that still satisfy the request, but is
2290	* smaller than previous one */
2291	if (ex->fe_len < bex->fe_len)
2292	*bex = *ex;
2293	}
2294
2295	ext4_mb_check_limits(ac, e4b, finish_group: 0);
2296	}
2297
2298	static noinline_for_stack
2299	void ext4_mb_try_best_found(struct ext4_allocation_context *ac,
2300	struct ext4_buddy *e4b)
2301	{
2302	struct ext4_free_extent ex = ac->ac_b_ex;
2303	ext4_group_t group = ex.fe_group;
2304	int max;
2305	int err;
2306
2307	BUG_ON(ex.fe_len <= 0);
2308	err = ext4_mb_load_buddy(sb: ac->ac_sb, group, e4b);
2309	if (err)
2310	return;
2311
2312	ext4_lock_group(sb: ac->ac_sb, group);
2313	if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
2314	goto out;
2315
2316	max = mb_find_extent(e4b, block: ex.fe_start, needed: ex.fe_len, ex: &ex);
2317
2318	if (max > 0) {
2319	ac->ac_b_ex = ex;
2320	ext4_mb_use_best_found(ac, e4b);
2321	}
2322
2323	out:
2324	ext4_unlock_group(sb: ac->ac_sb, group);
2325	ext4_mb_unload_buddy(e4b);
2326	}
2327
2328	static noinline_for_stack
2329	int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
2330	struct ext4_buddy *e4b)
2331	{
2332	ext4_group_t group = ac->ac_g_ex.fe_group;
2333	int max;
2334	int err;
2335	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
2336	struct ext4_group_info *grp = ext4_get_group_info(sb: ac->ac_sb, group);
2337	struct ext4_free_extent ex;
2338
2339	if (!grp)
2340	return -EFSCORRUPTED;
2341	if (!(ac->ac_flags & (EXT4_MB_HINT_TRY_GOAL | EXT4_MB_HINT_GOAL_ONLY)))
2342	return 0;
2343	if (grp->bb_free == 0)
2344	return 0;
2345
2346	err = ext4_mb_load_buddy(sb: ac->ac_sb, group, e4b);
2347	if (err)
2348	return err;
2349
2350	ext4_lock_group(sb: ac->ac_sb, group);
2351	if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
2352	goto out;
2353
2354	max = mb_find_extent(e4b, block: ac->ac_g_ex.fe_start,
2355	needed: ac->ac_g_ex.fe_len, ex: &ex);
2356	ex.fe_logical = 0xDEADFA11; /* debug value */
2357
2358	if (max >= ac->ac_g_ex.fe_len &&
2359	ac->ac_g_ex.fe_len == EXT4_NUM_B2C(sbi, sbi->s_stripe)) {
2360	ext4_fsblk_t start;
2361
2362	start = ext4_grp_offs_to_block(sb: ac->ac_sb, fex: &ex);
2363	/* use do_div to get remainder (would be 64-bit modulo) */
2364	if (do_div(start, sbi->s_stripe) == 0) {
2365	ac->ac_found++;
2366	ac->ac_b_ex = ex;
2367	ext4_mb_use_best_found(ac, e4b);
2368	}
2369	} else if (max >= ac->ac_g_ex.fe_len) {
2370	BUG_ON(ex.fe_len <= 0);
2371	BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
2372	BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
2373	ac->ac_found++;
2374	ac->ac_b_ex = ex;
2375	ext4_mb_use_best_found(ac, e4b);
2376	} else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
2377	/* Sometimes, caller may want to merge even small
2378	* number of blocks to an existing extent */
2379	BUG_ON(ex.fe_len <= 0);
2380	BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
2381	BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
2382	ac->ac_found++;
2383	ac->ac_b_ex = ex;
2384	ext4_mb_use_best_found(ac, e4b);
2385	}
2386	out:
2387	ext4_unlock_group(sb: ac->ac_sb, group);
2388	ext4_mb_unload_buddy(e4b);
2389
2390	return 0;
2391	}
2392
2393	/*
2394	* The routine scans buddy structures (not bitmap!) from given order
2395	* to max order and tries to find big enough chunk to satisfy the req
2396	*/
2397	static noinline_for_stack
2398	void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
2399	struct ext4_buddy *e4b)
2400	{
2401	struct super_block *sb = ac->ac_sb;
2402	struct ext4_group_info *grp = e4b->bd_info;
2403	void *buddy;
2404	int i;
2405	int k;
2406	int max;
2407
2408	BUG_ON(ac->ac_2order <= 0);
2409	for (i = ac->ac_2order; i < MB_NUM_ORDERS(sb); i++) {
2410	if (grp->bb_counters[i] == 0)
2411	continue;
2412
2413	buddy = mb_find_buddy(e4b, order: i, max: &max);
2414	if (WARN_RATELIMIT(buddy == NULL,
2415	"ext4: mb_simple_scan_group: mb_find_buddy failed, (%d)\n", i))
2416	continue;
2417
2418	k = mb_find_next_zero_bit(addr: buddy, max, start: 0);
2419	if (k >= max) {
2420	ext4_mark_group_bitmap_corrupted(sb: ac->ac_sb,
2421	block_group: e4b->bd_group,
2422	EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2423	ext4_grp_locked_error(ac->ac_sb, e4b->bd_group, 0, 0,
2424	"%d free clusters of order %d. But found 0",
2425	grp->bb_counters[i], i);
2426	break;
2427	}
2428	ac->ac_found++;
2429	ac->ac_cX_found[ac->ac_criteria]++;
2430
2431	ac->ac_b_ex.fe_len = 1 << i;
2432	ac->ac_b_ex.fe_start = k << i;
2433	ac->ac_b_ex.fe_group = e4b->bd_group;
2434
2435	ext4_mb_use_best_found(ac, e4b);
2436
2437	BUG_ON(ac->ac_f_ex.fe_len != ac->ac_g_ex.fe_len);
2438
2439	if (EXT4_SB(sb)->s_mb_stats)
2440	atomic_inc(v: &EXT4_SB(sb)->s_bal_2orders);
2441
2442	break;
2443	}
2444	}
2445
2446	/*
2447	* The routine scans the group and measures all found extents.
2448	* In order to optimize scanning, caller must pass number of
2449	* free blocks in the group, so the routine can know upper limit.
2450	*/
2451	static noinline_for_stack
2452	void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
2453	struct ext4_buddy *e4b)
2454	{
2455	struct super_block *sb = ac->ac_sb;
2456	void *bitmap = e4b->bd_bitmap;
2457	struct ext4_free_extent ex;
2458	int i, j, freelen;
2459	int free;
2460
2461	free = e4b->bd_info->bb_free;
2462	if (WARN_ON(free <= 0))
2463	return;
2464
2465	i = e4b->bd_info->bb_first_free;
2466
2467	while (free && ac->ac_status == AC_STATUS_CONTINUE) {
2468	i = mb_find_next_zero_bit(addr: bitmap,
2469	EXT4_CLUSTERS_PER_GROUP(sb), start: i);
2470	if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) {
2471	/*
2472	* IF we have corrupt bitmap, we won't find any
2473	* free blocks even though group info says we
2474	* have free blocks
2475	*/
2476	ext4_mark_group_bitmap_corrupted(sb, block_group: e4b->bd_group,
2477	EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2478	ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2479	"%d free clusters as per "
2480	"group info. But bitmap says 0",
2481	free);
2482	break;
2483	}
2484
2485	if (!ext4_mb_cr_expensive(cr: ac->ac_criteria)) {
2486	/*
2487	* In CR_GOAL_LEN_FAST and CR_BEST_AVAIL_LEN, we are
2488	* sure that this group will have a large enough
2489	* continuous free extent, so skip over the smaller free
2490	* extents
2491	*/
2492	j = mb_find_next_bit(addr: bitmap,
2493	EXT4_CLUSTERS_PER_GROUP(sb), start: i);
2494	freelen = j - i;
2495
2496	if (freelen < ac->ac_g_ex.fe_len) {
2497	i = j;
2498	free -= freelen;
2499	continue;
2500	}
2501	}
2502
2503	mb_find_extent(e4b, block: i, needed: ac->ac_g_ex.fe_len, ex: &ex);
2504	if (WARN_ON(ex.fe_len <= 0))
2505	break;
2506	if (free < ex.fe_len) {
2507	ext4_mark_group_bitmap_corrupted(sb, block_group: e4b->bd_group,
2508	EXT4_GROUP_INFO_BBITMAP_CORRUPT);
2509	ext4_grp_locked_error(sb, e4b->bd_group, 0, 0,
2510	"%d free clusters as per "
2511	"group info. But got %d blocks",
2512	free, ex.fe_len);
2513	/*
2514	* The number of free blocks differs. This mostly
2515	* indicate that the bitmap is corrupt. So exit
2516	* without claiming the space.
2517	*/
2518	break;
2519	}
2520	ex.fe_logical = 0xDEADC0DE; /* debug value */
2521	ext4_mb_measure_extent(ac, ex: &ex, e4b);
2522
2523	i += ex.fe_len;
2524	free -= ex.fe_len;
2525	}
2526
2527	ext4_mb_check_limits(ac, e4b, finish_group: 1);
2528	}
2529
2530	/*
2531	* This is a special case for storages like raid5
2532	* we try to find stripe-aligned chunks for stripe-size-multiple requests
2533	*/
2534	static noinline_for_stack
2535	void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
2536	struct ext4_buddy *e4b)
2537	{
2538	struct super_block *sb = ac->ac_sb;
2539	struct ext4_sb_info *sbi = EXT4_SB(sb);
2540	void *bitmap = e4b->bd_bitmap;
2541	struct ext4_free_extent ex;
2542	ext4_fsblk_t first_group_block;
2543	ext4_fsblk_t a;
2544	ext4_grpblk_t i, stripe;
2545	int max;
2546
2547	BUG_ON(sbi->s_stripe == 0);
2548
2549	/* find first stripe-aligned block in group */
2550	first_group_block = ext4_group_first_block_no(sb, group_no: e4b->bd_group);
2551
2552	a = first_group_block + sbi->s_stripe - 1;
2553	do_div(a, sbi->s_stripe);
2554	i = (a * sbi->s_stripe) - first_group_block;
2555
2556	stripe = EXT4_NUM_B2C(sbi, sbi->s_stripe);
2557	i = EXT4_B2C(sbi, i);
2558	while (i < EXT4_CLUSTERS_PER_GROUP(sb)) {
2559	if (!mb_test_bit(bit: i, addr: bitmap)) {
2560	max = mb_find_extent(e4b, block: i, needed: stripe, ex: &ex);
2561	if (max >= stripe) {
2562	ac->ac_found++;
2563	ac->ac_cX_found[ac->ac_criteria]++;
2564	ex.fe_logical = 0xDEADF00D; /* debug value */
2565	ac->ac_b_ex = ex;
2566	ext4_mb_use_best_found(ac, e4b);
2567	break;
2568	}
2569	}
2570	i += stripe;
2571	}
2572	}
2573
2574	/*
2575	* This is also called BEFORE we load the buddy bitmap.
2576	* Returns either 1 or 0 indicating that the group is either suitable
2577	* for the allocation or not.
2578	*/
2579	static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
2580	ext4_group_t group, enum criteria cr)
2581	{
2582	ext4_grpblk_t free, fragments;
2583	int flex_size = ext4_flex_bg_size(sbi: EXT4_SB(sb: ac->ac_sb));
2584	struct ext4_group_info *grp = ext4_get_group_info(sb: ac->ac_sb, group);
2585
2586	BUG_ON(cr < CR_POWER2_ALIGNED || cr >= EXT4_MB_NUM_CRS);
2587
2588	if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2589	return false;
2590
2591	free = grp->bb_free;
2592	if (free == 0)
2593	return false;
2594
2595	fragments = grp->bb_fragments;
2596	if (fragments == 0)
2597	return false;
2598
2599	switch (cr) {
2600	case CR_POWER2_ALIGNED:
2601	BUG_ON(ac->ac_2order == 0);
2602
2603	/* Avoid using the first bg of a flexgroup for data files */
2604	if ((ac->ac_flags & EXT4_MB_HINT_DATA) &&
2605	(flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) &&
2606	((group % flex_size) == 0))
2607	return false;
2608
2609	if (free < ac->ac_g_ex.fe_len)
2610	return false;
2611
2612	if (ac->ac_2order >= MB_NUM_ORDERS(ac->ac_sb))
2613	return true;
2614
2615	if (grp->bb_largest_free_order < ac->ac_2order)
2616	return false;
2617
2618	return true;
2619	case CR_GOAL_LEN_FAST:
2620	case CR_BEST_AVAIL_LEN:
2621	if ((free / fragments) >= ac->ac_g_ex.fe_len)
2622	return true;
2623	break;
2624	case CR_GOAL_LEN_SLOW:
2625	if (free >= ac->ac_g_ex.fe_len)
2626	return true;
2627	break;
2628	case CR_ANY_FREE:
2629	return true;
2630	default:
2631	BUG();
2632	}
2633
2634	return false;
2635	}
2636
2637	/*
2638	* This could return negative error code if something goes wrong
2639	* during ext4_mb_init_group(). This should not be called with
2640	* ext4_lock_group() held.
2641	*
2642	* Note: because we are conditionally operating with the group lock in
2643	* the EXT4_MB_STRICT_CHECK case, we need to fake out sparse in this
2644	* function using __acquire and __release. This means we need to be
2645	* super careful before messing with the error path handling via "goto
2646	* out"!
2647	*/
2648	static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac,
2649	ext4_group_t group, enum criteria cr)
2650	{
2651	struct ext4_group_info *grp = ext4_get_group_info(sb: ac->ac_sb, group);
2652	struct super_block *sb = ac->ac_sb;
2653	struct ext4_sb_info *sbi = EXT4_SB(sb);
2654	bool should_lock = ac->ac_flags & EXT4_MB_STRICT_CHECK;
2655	ext4_grpblk_t free;
2656	int ret = 0;
2657
2658	if (!grp)
2659	return -EFSCORRUPTED;
2660	if (sbi->s_mb_stats)
2661	atomic64_inc(v: &sbi->s_bal_cX_groups_considered[ac->ac_criteria]);
2662	if (should_lock) {
2663	ext4_lock_group(sb, group);
2664	__release(ext4_group_lock_ptr(sb, group));
2665	}
2666	free = grp->bb_free;
2667	if (free == 0)
2668	goto out;
2669	/*
2670	* In all criterias except CR_ANY_FREE we try to avoid groups that
2671	* can't possibly satisfy the full goal request due to insufficient
2672	* free blocks.
2673	*/
2674	if (cr < CR_ANY_FREE && free < ac->ac_g_ex.fe_len)
2675	goto out;
2676	if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
2677	goto out;
2678	if (should_lock) {
2679	__acquire(ext4_group_lock_ptr(sb, group));
2680	ext4_unlock_group(sb, group);
2681	}
2682
2683	/* We only do this if the grp has never been initialized */
2684	if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
2685	struct ext4_group_desc *gdp =
2686	ext4_get_group_desc(sb, block_group: group, NULL);
2687	int ret;
2688
2689	/*
2690	* CR_POWER2_ALIGNED/CR_GOAL_LEN_FAST is a very optimistic
2691	* search to find large good chunks almost for free. If buddy
2692	* data is not ready, then this optimization makes no sense. But
2693	* we never skip the first block group in a flex_bg, since this
2694	* gets used for metadata block allocation, and we want to make
2695	* sure we locate metadata blocks in the first block group in
2696	* the flex_bg if possible.
2697	*/
2698	if (!ext4_mb_cr_expensive(cr) &&
2699	(!sbi->s_log_groups_per_flex ||
2700	((group & ((1 << sbi->s_log_groups_per_flex) - 1)) != 0)) &&
2701	!(ext4_has_group_desc_csum(sb) &&
2702	(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))))
2703	return 0;
2704	ret = ext4_mb_init_group(sb, group, GFP_NOFS);
2705	if (ret)
2706	return ret;
2707	}
2708
2709	if (should_lock) {
2710	ext4_lock_group(sb, group);
2711	__release(ext4_group_lock_ptr(sb, group));
2712	}
2713	ret = ext4_mb_good_group(ac, group, cr);
2714	out:
2715	if (should_lock) {
2716	__acquire(ext4_group_lock_ptr(sb, group));
2717	ext4_unlock_group(sb, group);
2718	}
2719	return ret;
2720	}
2721
2722	/*
2723	* Start prefetching @nr block bitmaps starting at @group.
2724	* Return the next group which needs to be prefetched.
2725	*/
2726	ext4_group_t ext4_mb_prefetch(struct super_block *sb, ext4_group_t group,
2727	unsigned int nr, int *cnt)
2728	{
2729	ext4_group_t ngroups = ext4_get_groups_count(sb);
2730	struct buffer_head *bh;
2731	struct blk_plug plug;
2732
2733	blk_start_plug(&plug);
2734	while (nr-- > 0) {
2735	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, block_group: group,
2736	NULL);
2737	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
2738
2739	/*
2740	* Prefetch block groups with free blocks; but don't
2741	* bother if it is marked uninitialized on disk, since
2742	* it won't require I/O to read. Also only try to
2743	* prefetch once, so we avoid getblk() call, which can
2744	* be expensive.
2745	*/
2746	if (gdp && grp && !EXT4_MB_GRP_TEST_AND_SET_READ(grp) &&
2747	EXT4_MB_GRP_NEED_INIT(grp) &&
2748	ext4_free_group_clusters(sb, bg: gdp) > 0 ) {
2749	bh = ext4_read_block_bitmap_nowait(sb, block_group: group, ignore_locked: true);
2750	if (bh && !IS_ERR(ptr: bh)) {
2751	if (!buffer_uptodate(bh) && cnt)
2752	(*cnt)++;
2753	brelse(bh);
2754	}
2755	}
2756	if (++group >= ngroups)
2757	group = 0;
2758	}
2759	blk_finish_plug(&plug);
2760	return group;
2761	}
2762
2763	/*
2764	* Prefetching reads the block bitmap into the buffer cache; but we
2765	* need to make sure that the buddy bitmap in the page cache has been
2766	* initialized. Note that ext4_mb_init_group() will block if the I/O
2767	* is not yet completed, or indeed if it was not initiated by
2768	* ext4_mb_prefetch did not start the I/O.
2769	*
2770	* TODO: We should actually kick off the buddy bitmap setup in a work
2771	* queue when the buffer I/O is completed, so that we don't block
2772	* waiting for the block allocation bitmap read to finish when
2773	* ext4_mb_prefetch_fini is called from ext4_mb_regular_allocator().
2774	*/
2775	void ext4_mb_prefetch_fini(struct super_block *sb, ext4_group_t group,
2776	unsigned int nr)
2777	{
2778	struct ext4_group_desc *gdp;
2779	struct ext4_group_info *grp;
2780
2781	while (nr-- > 0) {
2782	if (!group)
2783	group = ext4_get_groups_count(sb);
2784	group--;
2785	gdp = ext4_get_group_desc(sb, block_group: group, NULL);
2786	grp = ext4_get_group_info(sb, group);
2787
2788	if (grp && gdp && EXT4_MB_GRP_NEED_INIT(grp) &&
2789	ext4_free_group_clusters(sb, bg: gdp) > 0) {
2790	if (ext4_mb_init_group(sb, group, GFP_NOFS))
2791	break;
2792	}
2793	}
2794	}
2795
2796	static noinline_for_stack int
2797	ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
2798	{
2799	ext4_group_t prefetch_grp = 0, ngroups, group, i;
2800	enum criteria new_cr, cr = CR_GOAL_LEN_FAST;
2801	int err = 0, first_err = 0;
2802	unsigned int nr = 0, prefetch_ios = 0;
2803	struct ext4_sb_info *sbi;
2804	struct super_block *sb;
2805	struct ext4_buddy e4b;
2806	int lost;
2807
2808	sb = ac->ac_sb;
2809	sbi = EXT4_SB(sb);
2810	ngroups = ext4_get_groups_count(sb);
2811	/* non-extent files are limited to low blocks/groups */
2812	if (!(ext4_test_inode_flag(inode: ac->ac_inode, bit: EXT4_INODE_EXTENTS)))
2813	ngroups = sbi->s_blockfile_groups;
2814
2815	BUG_ON(ac->ac_status == AC_STATUS_FOUND);
2816
2817	/* first, try the goal */
2818	err = ext4_mb_find_by_goal(ac, e4b: &e4b);
2819	if (err || ac->ac_status == AC_STATUS_FOUND)
2820	goto out;
2821
2822	if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
2823	goto out;
2824
2825	/*
2826	* ac->ac_2order is set only if the fe_len is a power of 2
2827	* if ac->ac_2order is set we also set criteria to CR_POWER2_ALIGNED
2828	* so that we try exact allocation using buddy.
2829	*/
2830	i = fls(x: ac->ac_g_ex.fe_len);
2831	ac->ac_2order = 0;
2832	/*
2833	* We search using buddy data only if the order of the request
2834	* is greater than equal to the sbi_s_mb_order2_reqs
2835	* You can tune it via /sys/fs/ext4/<partition>/mb_order2_req
2836	* We also support searching for power-of-two requests only for
2837	* requests upto maximum buddy size we have constructed.
2838	*/
2839	if (i >= sbi->s_mb_order2_reqs && i <= MB_NUM_ORDERS(sb)) {
2840	if (is_power_of_2(n: ac->ac_g_ex.fe_len))
2841	ac->ac_2order = array_index_nospec(i - 1,
2842	MB_NUM_ORDERS(sb));
2843	}
2844
2845	/* if stream allocation is enabled, use global goal */
2846	if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
2847	/* TBD: may be hot point */
2848	spin_lock(lock: &sbi->s_md_lock);
2849	ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
2850	ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
2851	spin_unlock(lock: &sbi->s_md_lock);
2852	}
2853
2854	/*
2855	* Let's just scan groups to find more-less suitable blocks We
2856	* start with CR_GOAL_LEN_FAST, unless it is power of 2
2857	* aligned, in which case let's do that faster approach first.
2858	*/
2859	if (ac->ac_2order)
2860	cr = CR_POWER2_ALIGNED;
2861	repeat:
2862	for (; cr < EXT4_MB_NUM_CRS && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
2863	ac->ac_criteria = cr;
2864	/*
2865	* searching for the right group start
2866	* from the goal value specified
2867	*/
2868	group = ac->ac_g_ex.fe_group;
2869	ac->ac_groups_linear_remaining = sbi->s_mb_max_linear_groups;
2870	prefetch_grp = group;
2871	nr = 0;
2872
2873	for (i = 0, new_cr = cr; i < ngroups; i++,
2874	ext4_mb_choose_next_group(ac, new_cr: &new_cr, group: &group, ngroups)) {
2875	int ret = 0;
2876
2877	cond_resched();
2878	if (new_cr != cr) {
2879	cr = new_cr;
2880	goto repeat;
2881	}
2882
2883	/*
2884	* Batch reads of the block allocation bitmaps
2885	* to get multiple READs in flight; limit
2886	* prefetching at inexpensive CR, otherwise mballoc
2887	* can spend a lot of time loading imperfect groups
2888	*/
2889	if ((prefetch_grp == group) &&
2890	(ext4_mb_cr_expensive(cr) ||
2891	prefetch_ios < sbi->s_mb_prefetch_limit)) {
2892	nr = sbi->s_mb_prefetch;
2893	if (ext4_has_feature_flex_bg(sb)) {
2894	nr = 1 << sbi->s_log_groups_per_flex;
2895	nr -= group & (nr - 1);
2896	nr = min(nr, sbi->s_mb_prefetch);
2897	}
2898	prefetch_grp = ext4_mb_prefetch(sb, group,
2899	nr, cnt: &prefetch_ios);
2900	}
2901
2902	/* This now checks without needing the buddy page */
2903	ret = ext4_mb_good_group_nolock(ac, group, cr);
2904	if (ret <= 0) {
2905	if (!first_err)
2906	first_err = ret;
2907	continue;
2908	}
2909
2910	err = ext4_mb_load_buddy(sb, group, e4b: &e4b);
2911	if (err)
2912	goto out;
2913
2914	ext4_lock_group(sb, group);
2915
2916	/*
2917	* We need to check again after locking the
2918	* block group
2919	*/
2920	ret = ext4_mb_good_group(ac, group, cr);
2921	if (ret == 0) {
2922	ext4_unlock_group(sb, group);
2923	ext4_mb_unload_buddy(e4b: &e4b);
2924	continue;
2925	}
2926
2927	ac->ac_groups_scanned++;
2928	if (cr == CR_POWER2_ALIGNED)
2929	ext4_mb_simple_scan_group(ac, e4b: &e4b);
2930	else {
2931	bool is_stripe_aligned =
2932	(sbi->s_stripe >=
2933	sbi->s_cluster_ratio) &&
2934	!(ac->ac_g_ex.fe_len %
2935	EXT4_NUM_B2C(sbi, sbi->s_stripe));
2936
2937	if ((cr == CR_GOAL_LEN_FAST ||
2938	cr == CR_BEST_AVAIL_LEN) &&
2939	is_stripe_aligned)
2940	ext4_mb_scan_aligned(ac, e4b: &e4b);
2941
2942	if (ac->ac_status == AC_STATUS_CONTINUE)
2943	ext4_mb_complex_scan_group(ac, e4b: &e4b);
2944	}
2945
2946	ext4_unlock_group(sb, group);
2947	ext4_mb_unload_buddy(e4b: &e4b);
2948
2949	if (ac->ac_status != AC_STATUS_CONTINUE)
2950	break;
2951	}
2952	/* Processed all groups and haven't found blocks */
2953	if (sbi->s_mb_stats && i == ngroups)
2954	atomic64_inc(v: &sbi->s_bal_cX_failed[cr]);
2955
2956	if (i == ngroups && ac->ac_criteria == CR_BEST_AVAIL_LEN)
2957	/* Reset goal length to original goal length before
2958	* falling into CR_GOAL_LEN_SLOW */
2959	ac->ac_g_ex.fe_len = ac->ac_orig_goal_len;
2960	}
2961
2962	if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
2963	!(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2964	/*
2965	* We've been searching too long. Let's try to allocate
2966	* the best chunk we've found so far
2967	*/
2968	ext4_mb_try_best_found(ac, e4b: &e4b);
2969	if (ac->ac_status != AC_STATUS_FOUND) {
2970	/*
2971	* Someone more lucky has already allocated it.
2972	* The only thing we can do is just take first
2973	* found block(s)
2974	*/
2975	lost = atomic_inc_return(v: &sbi->s_mb_lost_chunks);
2976	mb_debug(sb, "lost chunk, group: %u, start: %d, len: %d, lost: %d\n",
2977	ac->ac_b_ex.fe_group, ac->ac_b_ex.fe_start,
2978	ac->ac_b_ex.fe_len, lost);
2979
2980	ac->ac_b_ex.fe_group = 0;
2981	ac->ac_b_ex.fe_start = 0;
2982	ac->ac_b_ex.fe_len = 0;
2983	ac->ac_status = AC_STATUS_CONTINUE;
2984	ac->ac_flags |= EXT4_MB_HINT_FIRST;
2985	cr = CR_ANY_FREE;
2986	goto repeat;
2987	}
2988	}
2989
2990	if (sbi->s_mb_stats && ac->ac_status == AC_STATUS_FOUND)
2991	atomic64_inc(v: &sbi->s_bal_cX_hits[ac->ac_criteria]);
2992	out:
2993	if (!err && ac->ac_status != AC_STATUS_FOUND && first_err)
2994	err = first_err;
2995
2996	mb_debug(sb, "Best len %d, origin len %d, ac_status %u, ac_flags 0x%x, cr %d ret %d\n",
2997	ac->ac_b_ex.fe_len, ac->ac_o_ex.fe_len, ac->ac_status,
2998	ac->ac_flags, cr, err);
2999
3000	if (nr)
3001	ext4_mb_prefetch_fini(sb, group: prefetch_grp, nr);
3002
3003	return err;
3004	}
3005
3006	static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
3007	{
3008	struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3009	ext4_group_t group;
3010
3011	if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
3012	return NULL;
3013	group = *pos + 1;
3014	return (void *) ((unsigned long) group);
3015	}
3016
3017	static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
3018	{
3019	struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3020	ext4_group_t group;
3021
3022	++*pos;
3023	if (*pos < 0 || *pos >= ext4_get_groups_count(sb))
3024	return NULL;
3025	group = *pos + 1;
3026	return (void *) ((unsigned long) group);
3027	}
3028
3029	static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
3030	{
3031	struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3032	ext4_group_t group = (ext4_group_t) ((unsigned long) v);
3033	int i, err;
3034	char nbuf[16];
3035	struct ext4_buddy e4b;
3036	struct ext4_group_info *grinfo;
3037	unsigned char blocksize_bits = min_t(unsigned char,
3038	sb->s_blocksize_bits,
3039	EXT4_MAX_BLOCK_LOG_SIZE);
3040	DEFINE_RAW_FLEX(struct ext4_group_info, sg, bb_counters,
3041	EXT4_MAX_BLOCK_LOG_SIZE + 2);
3042
3043	group--;
3044	if (group == 0)
3045	seq_puts(m: seq, s: "#group: free frags first ["
3046	" 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
3047	" 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
3048
3049	i = (blocksize_bits + 2) * sizeof(sg->bb_counters[0]) +
3050	sizeof(struct ext4_group_info);
3051
3052	grinfo = ext4_get_group_info(sb, group);
3053	if (!grinfo)
3054	return 0;
3055	/* Load the group info in memory only if not already loaded. */
3056	if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
3057	err = ext4_mb_load_buddy(sb, group, e4b: &e4b);
3058	if (err) {
3059	seq_printf(m: seq, fmt: "#%-5u: %s\n", group, ext4_decode_error(NULL, errno: err, nbuf));
3060	return 0;
3061	}
3062	ext4_mb_unload_buddy(e4b: &e4b);
3063	}
3064
3065	/*
3066	* We care only about free space counters in the group info and
3067	* these are safe to access even after the buddy has been unloaded
3068	*/
3069	memcpy(sg, grinfo, i);
3070	seq_printf(m: seq, fmt: "#%-5u: %-5u %-5u %-5u [", group, sg->bb_free,
3071	sg->bb_fragments, sg->bb_first_free);
3072	for (i = 0; i <= 13; i++)
3073	seq_printf(m: seq, fmt: " %-5u", i <= blocksize_bits + 1 ?
3074	sg->bb_counters[i] : 0);
3075	seq_puts(m: seq, s: " ]");
3076	if (EXT4_MB_GRP_BBITMAP_CORRUPT(sg))
3077	seq_puts(m: seq, s: " Block bitmap corrupted!");
3078	seq_putc(m: seq, c: '\n');
3079	return 0;
3080	}
3081
3082	static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
3083	{
3084	}
3085
3086	const struct seq_operations ext4_mb_seq_groups_ops = {
3087	.start = ext4_mb_seq_groups_start,
3088	.next = ext4_mb_seq_groups_next,
3089	.stop = ext4_mb_seq_groups_stop,
3090	.show = ext4_mb_seq_groups_show,
3091	};
3092
3093	int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
3094	{
3095	struct super_block *sb = seq->private;
3096	struct ext4_sb_info *sbi = EXT4_SB(sb);
3097
3098	seq_puts(m: seq, s: "mballoc:\n");
3099	if (!sbi->s_mb_stats) {
3100	seq_puts(m: seq, s: "\tmb stats collection turned off.\n");
3101	seq_puts(
3102	m: seq,
3103	s: "\tTo enable, please write \"1\" to sysfs file mb_stats.\n");
3104	return 0;
3105	}
3106	seq_printf(m: seq, fmt: "\treqs: %u\n", atomic_read(v: &sbi->s_bal_reqs));
3107	seq_printf(m: seq, fmt: "\tsuccess: %u\n", atomic_read(v: &sbi->s_bal_success));
3108
3109	seq_printf(m: seq, fmt: "\tgroups_scanned: %u\n",
3110	atomic_read(v: &sbi->s_bal_groups_scanned));
3111
3112	/* CR_POWER2_ALIGNED stats */
3113	seq_puts(m: seq, s: "\tcr_p2_aligned_stats:\n");
3114	seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3115	atomic64_read(v: &sbi->s_bal_cX_hits[CR_POWER2_ALIGNED]));
3116	seq_printf(
3117	m: seq, fmt: "\t\tgroups_considered: %llu\n",
3118	atomic64_read(
3119	v: &sbi->s_bal_cX_groups_considered[CR_POWER2_ALIGNED]));
3120	seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3121	atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_POWER2_ALIGNED]));
3122	seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3123	atomic64_read(v: &sbi->s_bal_cX_failed[CR_POWER2_ALIGNED]));
3124	seq_printf(m: seq, fmt: "\t\tbad_suggestions: %u\n",
3125	atomic_read(v: &sbi->s_bal_p2_aligned_bad_suggestions));
3126
3127	/* CR_GOAL_LEN_FAST stats */
3128	seq_puts(m: seq, s: "\tcr_goal_fast_stats:\n");
3129	seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3130	atomic64_read(v: &sbi->s_bal_cX_hits[CR_GOAL_LEN_FAST]));
3131	seq_printf(m: seq, fmt: "\t\tgroups_considered: %llu\n",
3132	atomic64_read(
3133	v: &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_FAST]));
3134	seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3135	atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_FAST]));
3136	seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3137	atomic64_read(v: &sbi->s_bal_cX_failed[CR_GOAL_LEN_FAST]));
3138	seq_printf(m: seq, fmt: "\t\tbad_suggestions: %u\n",
3139	atomic_read(v: &sbi->s_bal_goal_fast_bad_suggestions));
3140
3141	/* CR_BEST_AVAIL_LEN stats */
3142	seq_puts(m: seq, s: "\tcr_best_avail_stats:\n");
3143	seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3144	atomic64_read(v: &sbi->s_bal_cX_hits[CR_BEST_AVAIL_LEN]));
3145	seq_printf(
3146	m: seq, fmt: "\t\tgroups_considered: %llu\n",
3147	atomic64_read(
3148	v: &sbi->s_bal_cX_groups_considered[CR_BEST_AVAIL_LEN]));
3149	seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3150	atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_BEST_AVAIL_LEN]));
3151	seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3152	atomic64_read(v: &sbi->s_bal_cX_failed[CR_BEST_AVAIL_LEN]));
3153	seq_printf(m: seq, fmt: "\t\tbad_suggestions: %u\n",
3154	atomic_read(v: &sbi->s_bal_best_avail_bad_suggestions));
3155
3156	/* CR_GOAL_LEN_SLOW stats */
3157	seq_puts(m: seq, s: "\tcr_goal_slow_stats:\n");
3158	seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3159	atomic64_read(v: &sbi->s_bal_cX_hits[CR_GOAL_LEN_SLOW]));
3160	seq_printf(m: seq, fmt: "\t\tgroups_considered: %llu\n",
3161	atomic64_read(
3162	v: &sbi->s_bal_cX_groups_considered[CR_GOAL_LEN_SLOW]));
3163	seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3164	atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_GOAL_LEN_SLOW]));
3165	seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3166	atomic64_read(v: &sbi->s_bal_cX_failed[CR_GOAL_LEN_SLOW]));
3167
3168	/* CR_ANY_FREE stats */
3169	seq_puts(m: seq, s: "\tcr_any_free_stats:\n");
3170	seq_printf(m: seq, fmt: "\t\thits: %llu\n",
3171	atomic64_read(v: &sbi->s_bal_cX_hits[CR_ANY_FREE]));
3172	seq_printf(
3173	m: seq, fmt: "\t\tgroups_considered: %llu\n",
3174	atomic64_read(v: &sbi->s_bal_cX_groups_considered[CR_ANY_FREE]));
3175	seq_printf(m: seq, fmt: "\t\textents_scanned: %u\n",
3176	atomic_read(v: &sbi->s_bal_cX_ex_scanned[CR_ANY_FREE]));
3177	seq_printf(m: seq, fmt: "\t\tuseless_loops: %llu\n",
3178	atomic64_read(v: &sbi->s_bal_cX_failed[CR_ANY_FREE]));
3179
3180	/* Aggregates */
3181	seq_printf(m: seq, fmt: "\textents_scanned: %u\n",
3182	atomic_read(v: &sbi->s_bal_ex_scanned));
3183	seq_printf(m: seq, fmt: "\t\tgoal_hits: %u\n", atomic_read(v: &sbi->s_bal_goals));
3184	seq_printf(m: seq, fmt: "\t\tlen_goal_hits: %u\n",
3185	atomic_read(v: &sbi->s_bal_len_goals));
3186	seq_printf(m: seq, fmt: "\t\t2^n_hits: %u\n", atomic_read(v: &sbi->s_bal_2orders));
3187	seq_printf(m: seq, fmt: "\t\tbreaks: %u\n", atomic_read(v: &sbi->s_bal_breaks));
3188	seq_printf(m: seq, fmt: "\t\tlost: %u\n", atomic_read(v: &sbi->s_mb_lost_chunks));
3189	seq_printf(m: seq, fmt: "\tbuddies_generated: %u/%u\n",
3190	atomic_read(v: &sbi->s_mb_buddies_generated),
3191	ext4_get_groups_count(sb));
3192	seq_printf(m: seq, fmt: "\tbuddies_time_used: %llu\n",
3193	atomic64_read(v: &sbi->s_mb_generation_time));
3194	seq_printf(m: seq, fmt: "\tpreallocated: %u\n",
3195	atomic_read(v: &sbi->s_mb_preallocated));
3196	seq_printf(m: seq, fmt: "\tdiscarded: %u\n", atomic_read(v: &sbi->s_mb_discarded));
3197	return 0;
3198	}
3199
3200	static void *ext4_mb_seq_structs_summary_start(struct seq_file *seq, loff_t *pos)
3201	{
3202	struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3203	unsigned long position;
3204
3205	if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb))
3206	return NULL;
3207	position = *pos + 1;
3208	return (void *) ((unsigned long) position);
3209	}
3210
3211	static void *ext4_mb_seq_structs_summary_next(struct seq_file *seq, void *v, loff_t *pos)
3212	{
3213	struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3214	unsigned long position;
3215
3216	++*pos;
3217	if (*pos < 0 || *pos >= 2*MB_NUM_ORDERS(sb))
3218	return NULL;
3219	position = *pos + 1;
3220	return (void *) ((unsigned long) position);
3221	}
3222
3223	static int ext4_mb_seq_structs_summary_show(struct seq_file *seq, void *v)
3224	{
3225	struct super_block *sb = pde_data(inode: file_inode(f: seq->file));
3226	struct ext4_sb_info *sbi = EXT4_SB(sb);
3227	unsigned long position = ((unsigned long) v);
3228	struct ext4_group_info *grp;
3229	unsigned int count;
3230
3231	position--;
3232	if (position >= MB_NUM_ORDERS(sb)) {
3233	position -= MB_NUM_ORDERS(sb);
3234	if (position == 0)
3235	seq_puts(m: seq, s: "avg_fragment_size_lists:\n");
3236
3237	count = 0;
3238	read_lock(&sbi->s_mb_avg_fragment_size_locks[position]);
3239	list_for_each_entry(grp, &sbi->s_mb_avg_fragment_size[position],
3240	bb_avg_fragment_size_node)
3241	count++;
3242	read_unlock(&sbi->s_mb_avg_fragment_size_locks[position]);
3243	seq_printf(m: seq, fmt: "\tlist_order_%u_groups: %u\n",
3244	(unsigned int)position, count);
3245	return 0;
3246	}
3247
3248	if (position == 0) {
3249	seq_printf(m: seq, fmt: "optimize_scan: %d\n",
3250	test_opt2(sb, MB_OPTIMIZE_SCAN) ? 1 : 0);
3251	seq_puts(m: seq, s: "max_free_order_lists:\n");
3252	}
3253	count = 0;
3254	read_lock(&sbi->s_mb_largest_free_orders_locks[position]);
3255	list_for_each_entry(grp, &sbi->s_mb_largest_free_orders[position],
3256	bb_largest_free_order_node)
3257	count++;
3258	read_unlock(&sbi->s_mb_largest_free_orders_locks[position]);
3259	seq_printf(m: seq, fmt: "\tlist_order_%u_groups: %u\n",
3260	(unsigned int)position, count);
3261
3262	return 0;
3263	}
3264
3265	static void ext4_mb_seq_structs_summary_stop(struct seq_file *seq, void *v)
3266	{
3267	}
3268
3269	const struct seq_operations ext4_mb_seq_structs_summary_ops = {
3270	.start = ext4_mb_seq_structs_summary_start,
3271	.next = ext4_mb_seq_structs_summary_next,
3272	.stop = ext4_mb_seq_structs_summary_stop,
3273	.show = ext4_mb_seq_structs_summary_show,
3274	};
3275
3276	static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
3277	{
3278	int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
3279	struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index];
3280
3281	BUG_ON(!cachep);
3282	return cachep;
3283	}
3284
3285	/*
3286	* Allocate the top-level s_group_info array for the specified number
3287	* of groups
3288	*/
3289	int ext4_mb_alloc_groupinfo(struct super_block *sb, ext4_group_t ngroups)
3290	{
3291	struct ext4_sb_info *sbi = EXT4_SB(sb);
3292	unsigned size;
3293	struct ext4_group_info ***old_groupinfo, ***new_groupinfo;
3294
3295	size = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >>
3296	EXT4_DESC_PER_BLOCK_BITS(sb);
3297	if (size <= sbi->s_group_info_size)
3298	return 0;
3299
3300	size = roundup_pow_of_two(sizeof(*sbi->s_group_info) * size);
3301	new_groupinfo = kvzalloc(size, GFP_KERNEL);
3302	if (!new_groupinfo) {
3303	ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group");
3304	return -ENOMEM;
3305	}
3306	rcu_read_lock();
3307	old_groupinfo = rcu_dereference(sbi->s_group_info);
3308	if (old_groupinfo)
3309	memcpy(new_groupinfo, old_groupinfo,
3310	sbi->s_group_info_size * sizeof(*sbi->s_group_info));
3311	rcu_read_unlock();
3312	rcu_assign_pointer(sbi->s_group_info, new_groupinfo);
3313	sbi->s_group_info_size = size / sizeof(*sbi->s_group_info);
3314	if (old_groupinfo)
3315	ext4_kvfree_array_rcu(to_free: old_groupinfo);
3316	ext4_debug("allocated s_groupinfo array for %d meta_bg's\n",
3317	sbi->s_group_info_size);
3318	return 0;
3319	}
3320
3321	/* Create and initialize ext4_group_info data for the given group. */
3322	int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
3323	struct ext4_group_desc *desc)
3324	{
3325	int i;
3326	int metalen = 0;
3327	int idx = group >> EXT4_DESC_PER_BLOCK_BITS(sb);
3328	struct ext4_sb_info *sbi = EXT4_SB(sb);
3329	struct ext4_group_info **meta_group_info;
3330	struct kmem_cache *cachep = get_groupinfo_cache(blocksize_bits: sb->s_blocksize_bits);
3331
3332	/*
3333	* First check if this group is the first of a reserved block.
3334	* If it's true, we have to allocate a new table of pointers
3335	* to ext4_group_info structures
3336	*/
3337	if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
3338	metalen = sizeof(*meta_group_info) <<
3339	EXT4_DESC_PER_BLOCK_BITS(sb);
3340	meta_group_info = kmalloc(metalen, GFP_NOFS);
3341	if (meta_group_info == NULL) {
3342	ext4_msg(sb, KERN_ERR, "can't allocate mem "
3343	"for a buddy group");
3344	return -ENOMEM;
3345	}
3346	rcu_read_lock();
3347	rcu_dereference(sbi->s_group_info)[idx] = meta_group_info;
3348	rcu_read_unlock();
3349	}
3350
3351	meta_group_info = sbi_array_rcu_deref(sbi, s_group_info, idx);
3352	i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
3353
3354	meta_group_info[i] = kmem_cache_zalloc(cachep, GFP_NOFS);
3355	if (meta_group_info[i] == NULL) {
3356	ext4_msg(sb, KERN_ERR, "can't allocate buddy mem");
3357	goto exit_group_info;
3358	}
3359	set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
3360	addr: &(meta_group_info[i]->bb_state));
3361
3362	/*
3363	* initialize bb_free to be able to skip
3364	* empty groups without initialization
3365	*/
3366	if (ext4_has_group_desc_csum(sb) &&
3367	(desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
3368	meta_group_info[i]->bb_free =
3369	ext4_free_clusters_after_init(sb, block_group: group, gdp: desc);
3370	} else {
3371	meta_group_info[i]->bb_free =
3372	ext4_free_group_clusters(sb, bg: desc);
3373	}
3374
3375	INIT_LIST_HEAD(list: &meta_group_info[i]->bb_prealloc_list);
3376	init_rwsem(&meta_group_info[i]->alloc_sem);
3377	meta_group_info[i]->bb_free_root = RB_ROOT;
3378	INIT_LIST_HEAD(list: &meta_group_info[i]->bb_largest_free_order_node);
3379	INIT_LIST_HEAD(list: &meta_group_info[i]->bb_avg_fragment_size_node);
3380	meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
3381	meta_group_info[i]->bb_avg_fragment_size_order = -1; /* uninit */
3382	meta_group_info[i]->bb_group = group;
3383
3384	mb_group_bb_bitmap_alloc(sb, grp: meta_group_info[i], group);
3385	return 0;
3386
3387	exit_group_info:
3388	/* If a meta_group_info table has been allocated, release it now */
3389	if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
3390	struct ext4_group_info ***group_info;
3391
3392	rcu_read_lock();
3393	group_info = rcu_dereference(sbi->s_group_info);
3394	kfree(objp: group_info[idx]);
3395	group_info[idx] = NULL;
3396	rcu_read_unlock();
3397	}
3398	return -ENOMEM;
3399	} /* ext4_mb_add_groupinfo */
3400
3401	static int ext4_mb_init_backend(struct super_block *sb)
3402	{
3403	ext4_group_t ngroups = ext4_get_groups_count(sb);
3404	ext4_group_t i;
3405	struct ext4_sb_info *sbi = EXT4_SB(sb);
3406	int err;
3407	struct ext4_group_desc *desc;
3408	struct ext4_group_info ***group_info;
3409	struct kmem_cache *cachep;
3410
3411	err = ext4_mb_alloc_groupinfo(sb, ngroups);
3412	if (err)
3413	return err;
3414
3415	sbi->s_buddy_cache = new_inode(sb);
3416	if (sbi->s_buddy_cache == NULL) {
3417	ext4_msg(sb, KERN_ERR, "can't get new inode");
3418	goto err_freesgi;
3419	}
3420	/* To avoid potentially colliding with an valid on-disk inode number,
3421	* use EXT4_BAD_INO for the buddy cache inode number. This inode is
3422	* not in the inode hash, so it should never be found by iget(), but
3423	* this will avoid confusion if it ever shows up during debugging. */
3424	sbi->s_buddy_cache->i_ino = EXT4_BAD_INO;
3425	EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
3426	for (i = 0; i < ngroups; i++) {
3427	cond_resched();
3428	desc = ext4_get_group_desc(sb, block_group: i, NULL);
3429	if (desc == NULL) {
3430	ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i);
3431	goto err_freebuddy;
3432	}
3433	if (ext4_mb_add_groupinfo(sb, group: i, desc) != 0)
3434	goto err_freebuddy;
3435	}
3436
3437	if (ext4_has_feature_flex_bg(sb)) {
3438	/* a single flex group is supposed to be read by a single IO.
3439	* 2 ^ s_log_groups_per_flex != UINT_MAX as s_mb_prefetch is
3440	* unsigned integer, so the maximum shift is 32.
3441	*/
3442	if (sbi->s_es->s_log_groups_per_flex >= 32) {
3443	ext4_msg(sb, KERN_ERR, "too many log groups per flexible block group");
3444	goto err_freebuddy;
3445	}
3446	sbi->s_mb_prefetch = min_t(uint, 1 << sbi->s_es->s_log_groups_per_flex,
3447	BLK_MAX_SEGMENT_SIZE >> (sb->s_blocksize_bits - 9));
3448	sbi->s_mb_prefetch *= 8; /* 8 prefetch IOs in flight at most */
3449	} else {
3450	sbi->s_mb_prefetch = 32;
3451	}
3452	if (sbi->s_mb_prefetch > ext4_get_groups_count(sb))
3453	sbi->s_mb_prefetch = ext4_get_groups_count(sb);
3454	/*
3455	* now many real IOs to prefetch within a single allocation at
3456	* CR_POWER2_ALIGNED. Given CR_POWER2_ALIGNED is an CPU-related
3457	* optimization we shouldn't try to load too many groups, at some point
3458	* we should start to use what we've got in memory.
3459	* with an average random access time 5ms, it'd take a second to get
3460	* 200 groups (* N with flex_bg), so let's make this limit 4
3461	*/
3462	sbi->s_mb_prefetch_limit = sbi->s_mb_prefetch * 4;
3463	if (sbi->s_mb_prefetch_limit > ext4_get_groups_count(sb))
3464	sbi->s_mb_prefetch_limit = ext4_get_groups_count(sb);
3465
3466	return 0;
3467
3468	err_freebuddy:
3469	cachep = get_groupinfo_cache(blocksize_bits: sb->s_blocksize_bits);
3470	while (i-- > 0) {
3471	struct ext4_group_info *grp = ext4_get_group_info(sb, group: i);
3472
3473	if (grp)
3474	kmem_cache_free(s: cachep, objp: grp);
3475	}
3476	i = sbi->s_group_info_size;
3477	rcu_read_lock();
3478	group_info = rcu_dereference(sbi->s_group_info);
3479	while (i-- > 0)
3480	kfree(objp: group_info[i]);
3481	rcu_read_unlock();
3482	iput(sbi->s_buddy_cache);
3483	err_freesgi:
3484	rcu_read_lock();
3485	kvfree(rcu_dereference(sbi->s_group_info));
3486	rcu_read_unlock();
3487	return -ENOMEM;
3488	}
3489
3490	static void ext4_groupinfo_destroy_slabs(void)
3491	{
3492	int i;
3493
3494	for (i = 0; i < NR_GRPINFO_CACHES; i++) {
3495	kmem_cache_destroy(s: ext4_groupinfo_caches[i]);
3496	ext4_groupinfo_caches[i] = NULL;
3497	}
3498	}
3499
3500	static int ext4_groupinfo_create_slab(size_t size)
3501	{
3502	static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex);
3503	int slab_size;
3504	int blocksize_bits = order_base_2(size);
3505	int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
3506	struct kmem_cache *cachep;
3507
3508	if (cache_index >= NR_GRPINFO_CACHES)
3509	return -EINVAL;
3510
3511	if (unlikely(cache_index < 0))
3512	cache_index = 0;
3513
3514	mutex_lock(&ext4_grpinfo_slab_create_mutex);
3515	if (ext4_groupinfo_caches[cache_index]) {
3516	mutex_unlock(lock: &ext4_grpinfo_slab_create_mutex);
3517	return 0; /* Already created */
3518	}
3519
3520	slab_size = offsetof(struct ext4_group_info,
3521	bb_counters[blocksize_bits + 2]);
3522
3523	cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index],
3524	slab_size, 0, SLAB_RECLAIM_ACCOUNT,
3525	NULL);
3526
3527	ext4_groupinfo_caches[cache_index] = cachep;
3528
3529	mutex_unlock(lock: &ext4_grpinfo_slab_create_mutex);
3530	if (!cachep) {
3531	printk(KERN_EMERG
3532	"EXT4-fs: no memory for groupinfo slab cache\n");
3533	return -ENOMEM;
3534	}
3535
3536	return 0;
3537	}
3538
3539	static void ext4_discard_work(struct work_struct *work)
3540	{
3541	struct ext4_sb_info *sbi = container_of(work,
3542	struct ext4_sb_info, s_discard_work);
3543	struct super_block *sb = sbi->s_sb;
3544	struct ext4_free_data *fd, *nfd;
3545	struct ext4_buddy e4b;
3546	LIST_HEAD(discard_list);
3547	ext4_group_t grp, load_grp;
3548	int err = 0;
3549
3550	spin_lock(lock: &sbi->s_md_lock);
3551	list_splice_init(list: &sbi->s_discard_list, head: &discard_list);
3552	spin_unlock(lock: &sbi->s_md_lock);
3553
3554	load_grp = UINT_MAX;
3555	list_for_each_entry_safe(fd, nfd, &discard_list, efd_list) {
3556	/*
3557	* If filesystem is umounting or no memory or suffering
3558	* from no space, give up the discard
3559	*/
3560	if ((sb->s_flags & SB_ACTIVE) && !err &&
3561	!atomic_read(v: &sbi->s_retry_alloc_pending)) {
3562	grp = fd->efd_group;
3563	if (grp != load_grp) {
3564	if (load_grp != UINT_MAX)
3565	ext4_mb_unload_buddy(e4b: &e4b);
3566
3567	err = ext4_mb_load_buddy(sb, group: grp, e4b: &e4b);
3568	if (err) {
3569	kmem_cache_free(s: ext4_free_data_cachep, objp: fd);
3570	load_grp = UINT_MAX;
3571	continue;
3572	} else {
3573	load_grp = grp;
3574	}
3575	}
3576
3577	ext4_lock_group(sb, group: grp);
3578	ext4_try_to_trim_range(sb, e4b: &e4b, start: fd->efd_start_cluster,
3579	max: fd->efd_start_cluster + fd->efd_count - 1, minblocks: 1);
3580	ext4_unlock_group(sb, group: grp);
3581	}
3582	kmem_cache_free(s: ext4_free_data_cachep, objp: fd);
3583	}
3584
3585	if (load_grp != UINT_MAX)
3586	ext4_mb_unload_buddy(e4b: &e4b);
3587	}
3588
3589	int ext4_mb_init(struct super_block *sb)
3590	{
3591	struct ext4_sb_info *sbi = EXT4_SB(sb);
3592	unsigned i, j;
3593	unsigned offset, offset_incr;
3594	unsigned max;
3595	int ret;
3596
3597	i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_offsets);
3598
3599	sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
3600	if (sbi->s_mb_offsets == NULL) {
3601	ret = -ENOMEM;
3602	goto out;
3603	}
3604
3605	i = MB_NUM_ORDERS(sb) * sizeof(*sbi->s_mb_maxs);
3606	sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
3607	if (sbi->s_mb_maxs == NULL) {
3608	ret = -ENOMEM;
3609	goto out;
3610	}
3611
3612	ret = ext4_groupinfo_create_slab(size: sb->s_blocksize);
3613	if (ret < 0)
3614	goto out;
3615
3616	/* order 0 is regular bitmap */
3617	sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
3618	sbi->s_mb_offsets[0] = 0;
3619
3620	i = 1;
3621	offset = 0;
3622	offset_incr = 1 << (sb->s_blocksize_bits - 1);
3623	max = sb->s_blocksize << 2;
3624	do {
3625	sbi->s_mb_offsets[i] = offset;
3626	sbi->s_mb_maxs[i] = max;
3627	offset += offset_incr;
3628	offset_incr = offset_incr >> 1;
3629	max = max >> 1;
3630	i++;
3631	} while (i < MB_NUM_ORDERS(sb));
3632
3633	sbi->s_mb_avg_fragment_size =
3634	kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct list_head),
3635	GFP_KERNEL);
3636	if (!sbi->s_mb_avg_fragment_size) {
3637	ret = -ENOMEM;
3638	goto out;
3639	}
3640	sbi->s_mb_avg_fragment_size_locks =
3641	kmalloc_array(MB_NUM_ORDERS(sb), sizeof(rwlock_t),
3642	GFP_KERNEL);
3643	if (!sbi->s_mb_avg_fragment_size_locks) {
3644	ret = -ENOMEM;
3645	goto out;
3646	}
3647	for (i = 0; i < MB_NUM_ORDERS(sb); i++) {
3648	INIT_LIST_HEAD(list: &sbi->s_mb_avg_fragment_size[i]);
3649	rwlock_init(&sbi->s_mb_avg_fragment_size_locks[i]);
3650	}
3651	sbi->s_mb_largest_free_orders =
3652	kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct list_head),
3653	GFP_KERNEL);
3654	if (!sbi->s_mb_largest_free_orders) {
3655	ret = -ENOMEM;
3656	goto out;
3657	}
3658	sbi->s_mb_largest_free_orders_locks =
3659	kmalloc_array(MB_NUM_ORDERS(sb), sizeof(rwlock_t),
3660	GFP_KERNEL);
3661	if (!sbi->s_mb_largest_free_orders_locks) {
3662	ret = -ENOMEM;
3663	goto out;
3664	}
3665	for (i = 0; i < MB_NUM_ORDERS(sb); i++) {
3666	INIT_LIST_HEAD(list: &sbi->s_mb_largest_free_orders[i]);
3667	rwlock_init(&sbi->s_mb_largest_free_orders_locks[i]);
3668	}
3669
3670	spin_lock_init(&sbi->s_md_lock);
3671	sbi->s_mb_free_pending = 0;
3672	INIT_LIST_HEAD(list: &sbi->s_freed_data_list[0]);
3673	INIT_LIST_HEAD(list: &sbi->s_freed_data_list[1]);
3674	INIT_LIST_HEAD(list: &sbi->s_discard_list);
3675	INIT_WORK(&sbi->s_discard_work, ext4_discard_work);
3676	atomic_set(v: &sbi->s_retry_alloc_pending, i: 0);
3677
3678	sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
3679	sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
3680	sbi->s_mb_stats = MB_DEFAULT_STATS;
3681	sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
3682	sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
3683	sbi->s_mb_best_avail_max_trim_order = MB_DEFAULT_BEST_AVAIL_TRIM_ORDER;
3684
3685	/*
3686	* The default group preallocation is 512, which for 4k block
3687	* sizes translates to 2 megabytes. However for bigalloc file
3688	* systems, this is probably too big (i.e, if the cluster size
3689	* is 1 megabyte, then group preallocation size becomes half a
3690	* gigabyte!). As a default, we will keep a two megabyte
3691	* group pralloc size for cluster sizes up to 64k, and after
3692	* that, we will force a minimum group preallocation size of
3693	* 32 clusters. This translates to 8 megs when the cluster
3694	* size is 256k, and 32 megs when the cluster size is 1 meg,
3695	* which seems reasonable as a default.
3696	*/
3697	sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >>
3698	sbi->s_cluster_bits, 32);
3699	/*
3700	* If there is a s_stripe > 1, then we set the s_mb_group_prealloc
3701	* to the lowest multiple of s_stripe which is bigger than
3702	* the s_mb_group_prealloc as determined above. We want
3703	* the preallocation size to be an exact multiple of the
3704	* RAID stripe size so that preallocations don't fragment
3705	* the stripes.
3706	*/
3707	if (sbi->s_stripe > 1) {
3708	sbi->s_mb_group_prealloc = roundup(
3709	sbi->s_mb_group_prealloc, EXT4_NUM_B2C(sbi, sbi->s_stripe));
3710	}
3711
3712	sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
3713	if (sbi->s_locality_groups == NULL) {
3714	ret = -ENOMEM;
3715	goto out;
3716	}
3717	for_each_possible_cpu(i) {
3718	struct ext4_locality_group *lg;
3719	lg = per_cpu_ptr(sbi->s_locality_groups, i);
3720	mutex_init(&lg->lg_mutex);
3721	for (j = 0; j < PREALLOC_TB_SIZE; j++)
3722	INIT_LIST_HEAD(list: &lg->lg_prealloc_list[j]);
3723	spin_lock_init(&lg->lg_prealloc_lock);
3724	}
3725
3726	if (bdev_nonrot(bdev: sb->s_bdev))
3727	sbi->s_mb_max_linear_groups = 0;
3728	else
3729	sbi->s_mb_max_linear_groups = MB_DEFAULT_LINEAR_LIMIT;
3730	/* init file for buddy data */
3731	ret = ext4_mb_init_backend(sb);
3732	if (ret != 0)
3733	goto out_free_locality_groups;
3734
3735	return 0;
3736
3737	out_free_locality_groups:
3738	free_percpu(pdata: sbi->s_locality_groups);
3739	sbi->s_locality_groups = NULL;
3740	out:
3741	kfree(objp: sbi->s_mb_avg_fragment_size);
3742	kfree(objp: sbi->s_mb_avg_fragment_size_locks);
3743	kfree(objp: sbi->s_mb_largest_free_orders);
3744	kfree(objp: sbi->s_mb_largest_free_orders_locks);
3745	kfree(objp: sbi->s_mb_offsets);
3746	sbi->s_mb_offsets = NULL;
3747	kfree(objp: sbi->s_mb_maxs);
3748	sbi->s_mb_maxs = NULL;
3749	return ret;
3750	}
3751
3752	/* need to called with the ext4 group lock held */
3753	static int ext4_mb_cleanup_pa(struct ext4_group_info *grp)
3754	{
3755	struct ext4_prealloc_space *pa;
3756	struct list_head *cur, *tmp;
3757	int count = 0;
3758
3759	list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
3760	pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3761	list_del(entry: &pa->pa_group_list);
3762	count++;
3763	kmem_cache_free(s: ext4_pspace_cachep, objp: pa);
3764	}
3765	return count;
3766	}
3767
3768	void ext4_mb_release(struct super_block *sb)
3769	{
3770	ext4_group_t ngroups = ext4_get_groups_count(sb);
3771	ext4_group_t i;
3772	int num_meta_group_infos;
3773	struct ext4_group_info *grinfo, ***group_info;
3774	struct ext4_sb_info *sbi = EXT4_SB(sb);
3775	struct kmem_cache *cachep = get_groupinfo_cache(blocksize_bits: sb->s_blocksize_bits);
3776	int count;
3777
3778	if (test_opt(sb, DISCARD)) {
3779	/*
3780	* wait the discard work to drain all of ext4_free_data
3781	*/
3782	flush_work(work: &sbi->s_discard_work);
3783	WARN_ON_ONCE(!list_empty(&sbi->s_discard_list));
3784	}
3785
3786	if (sbi->s_group_info) {
3787	for (i = 0; i < ngroups; i++) {
3788	cond_resched();
3789	grinfo = ext4_get_group_info(sb, group: i);
3790	if (!grinfo)
3791	continue;
3792	mb_group_bb_bitmap_free(grp: grinfo);
3793	ext4_lock_group(sb, group: i);
3794	count = ext4_mb_cleanup_pa(grp: grinfo);
3795	if (count)
3796	mb_debug(sb, "mballoc: %d PAs left\n",
3797	count);
3798	ext4_unlock_group(sb, group: i);
3799	kmem_cache_free(s: cachep, objp: grinfo);
3800	}
3801	num_meta_group_infos = (ngroups +
3802	EXT4_DESC_PER_BLOCK(sb) - 1) >>
3803	EXT4_DESC_PER_BLOCK_BITS(sb);
3804	rcu_read_lock();
3805	group_info = rcu_dereference(sbi->s_group_info);
3806	for (i = 0; i < num_meta_group_infos; i++)
3807	kfree(objp: group_info[i]);
3808	kvfree(addr: group_info);
3809	rcu_read_unlock();
3810	}
3811	kfree(objp: sbi->s_mb_avg_fragment_size);
3812	kfree(objp: sbi->s_mb_avg_fragment_size_locks);
3813	kfree(objp: sbi->s_mb_largest_free_orders);
3814	kfree(objp: sbi->s_mb_largest_free_orders_locks);
3815	kfree(objp: sbi->s_mb_offsets);
3816	kfree(objp: sbi->s_mb_maxs);
3817	iput(sbi->s_buddy_cache);
3818	if (sbi->s_mb_stats) {
3819	ext4_msg(sb, KERN_INFO,
3820	"mballoc: %u blocks %u reqs (%u success)",
3821	atomic_read(&sbi->s_bal_allocated),
3822	atomic_read(&sbi->s_bal_reqs),
3823	atomic_read(&sbi->s_bal_success));
3824	ext4_msg(sb, KERN_INFO,
3825	"mballoc: %u extents scanned, %u groups scanned, %u goal hits, "
3826	"%u 2^N hits, %u breaks, %u lost",
3827	atomic_read(&sbi->s_bal_ex_scanned),
3828	atomic_read(&sbi->s_bal_groups_scanned),
3829	atomic_read(&sbi->s_bal_goals),
3830	atomic_read(&sbi->s_bal_2orders),
3831	atomic_read(&sbi->s_bal_breaks),
3832	atomic_read(&sbi->s_mb_lost_chunks));
3833	ext4_msg(sb, KERN_INFO,
3834	"mballoc: %u generated and it took %llu",
3835	atomic_read(&sbi->s_mb_buddies_generated),
3836	atomic64_read(&sbi->s_mb_generation_time));
3837	ext4_msg(sb, KERN_INFO,
3838	"mballoc: %u preallocated, %u discarded",
3839	atomic_read(&sbi->s_mb_preallocated),
3840	atomic_read(&sbi->s_mb_discarded));
3841	}
3842
3843	free_percpu(pdata: sbi->s_locality_groups);
3844	}
3845
3846	static inline int ext4_issue_discard(struct super_block *sb,
3847	ext4_group_t block_group, ext4_grpblk_t cluster, int count)
3848	{
3849	ext4_fsblk_t discard_block;
3850
3851	discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) +
3852	ext4_group_first_block_no(sb, group_no: block_group));
3853	count = EXT4_C2B(EXT4_SB(sb), count);
3854	trace_ext4_discard_blocks(sb,
3855	blk: (unsigned long long) discard_block, count);
3856
3857	return sb_issue_discard(sb, block: discard_block, nr_blocks: count, GFP_NOFS, flags: 0);
3858	}
3859
3860	static void ext4_free_data_in_buddy(struct super_block *sb,
3861	struct ext4_free_data *entry)
3862	{
3863	struct ext4_buddy e4b;
3864	struct ext4_group_info *db;
3865	int err, count = 0;
3866
3867	mb_debug(sb, "gonna free %u blocks in group %u (0x%p):",
3868	entry->efd_count, entry->efd_group, entry);
3869
3870	err = ext4_mb_load_buddy(sb, group: entry->efd_group, e4b: &e4b);
3871	/* we expect to find existing buddy because it's pinned */
3872	BUG_ON(err != 0);
3873
3874	spin_lock(lock: &EXT4_SB(sb)->s_md_lock);
3875	EXT4_SB(sb)->s_mb_free_pending -= entry->efd_count;
3876	spin_unlock(lock: &EXT4_SB(sb)->s_md_lock);
3877
3878	db = e4b.bd_info;
3879	/* there are blocks to put in buddy to make them really free */
3880	count += entry->efd_count;
3881	ext4_lock_group(sb, group: entry->efd_group);
3882	/* Take it out of per group rb tree */
3883	rb_erase(&entry->efd_node, &(db->bb_free_root));
3884	mb_free_blocks(NULL, e4b: &e4b, first: entry->efd_start_cluster, count: entry->efd_count);
3885
3886	/*
3887	* Clear the trimmed flag for the group so that the next
3888	* ext4_trim_fs can trim it.
3889	*/
3890	EXT4_MB_GRP_CLEAR_TRIMMED(db);
3891
3892	if (!db->bb_free_root.rb_node) {
3893	/* No more items in the per group rb tree
3894	* balance refcounts from ext4_mb_free_metadata()
3895	*/
3896	folio_put(folio: e4b.bd_buddy_folio);
3897	folio_put(folio: e4b.bd_bitmap_folio);
3898	}
3899	ext4_unlock_group(sb, group: entry->efd_group);
3900	ext4_mb_unload_buddy(e4b: &e4b);
3901
3902	mb_debug(sb, "freed %d blocks in 1 structures\n", count);
3903	}
3904
3905	/*
3906	* This function is called by the jbd2 layer once the commit has finished,
3907	* so we know we can free the blocks that were released with that commit.
3908	*/
3909	void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid)
3910	{
3911	struct ext4_sb_info *sbi = EXT4_SB(sb);
3912	struct ext4_free_data *entry, *tmp;
3913	LIST_HEAD(freed_data_list);
3914	struct list_head *s_freed_head = &sbi->s_freed_data_list[commit_tid & 1];
3915	bool wake;
3916
3917	list_replace_init(old: s_freed_head, new: &freed_data_list);
3918
3919	list_for_each_entry(entry, &freed_data_list, efd_list)
3920	ext4_free_data_in_buddy(sb, entry);
3921
3922	if (test_opt(sb, DISCARD)) {
3923	spin_lock(lock: &sbi->s_md_lock);
3924	wake = list_empty(head: &sbi->s_discard_list);
3925	list_splice_tail(list: &freed_data_list, head: &sbi->s_discard_list);
3926	spin_unlock(lock: &sbi->s_md_lock);
3927	if (wake)
3928	queue_work(wq: system_unbound_wq, work: &sbi->s_discard_work);
3929	} else {
3930	list_for_each_entry_safe(entry, tmp, &freed_data_list, efd_list)
3931	kmem_cache_free(s: ext4_free_data_cachep, objp: entry);
3932	}
3933	}
3934
3935	int __init ext4_init_mballoc(void)
3936	{
3937	ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space,
3938	SLAB_RECLAIM_ACCOUNT);
3939	if (ext4_pspace_cachep == NULL)
3940	goto out;
3941
3942	ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context,
3943	SLAB_RECLAIM_ACCOUNT);
3944	if (ext4_ac_cachep == NULL)
3945	goto out_pa_free;
3946
3947	ext4_free_data_cachep = KMEM_CACHE(ext4_free_data,
3948	SLAB_RECLAIM_ACCOUNT);
3949	if (ext4_free_data_cachep == NULL)
3950	goto out_ac_free;
3951
3952	return 0;
3953
3954	out_ac_free:
3955	kmem_cache_destroy(s: ext4_ac_cachep);
3956	out_pa_free:
3957	kmem_cache_destroy(s: ext4_pspace_cachep);
3958	out:
3959	return -ENOMEM;
3960	}
3961
3962	void ext4_exit_mballoc(void)
3963	{
3964	/*
3965	* Wait for completion of call_rcu()'s on ext4_pspace_cachep
3966	* before destroying the slab cache.
3967	*/
3968	rcu_barrier();
3969	kmem_cache_destroy(s: ext4_pspace_cachep);
3970	kmem_cache_destroy(s: ext4_ac_cachep);
3971	kmem_cache_destroy(s: ext4_free_data_cachep);
3972	ext4_groupinfo_destroy_slabs();
3973	}
3974
3975	#define EXT4_MB_BITMAP_MARKED_CHECK 0x0001
3976	#define EXT4_MB_SYNC_UPDATE 0x0002
3977	static int
3978	ext4_mb_mark_context(handle_t *handle, struct super_block *sb, bool state,
3979	ext4_group_t group, ext4_grpblk_t blkoff,
3980	ext4_grpblk_t len, int flags, ext4_grpblk_t *ret_changed)
3981	{
3982	struct ext4_sb_info *sbi = EXT4_SB(sb);
3983	struct buffer_head *bitmap_bh = NULL;
3984	struct ext4_group_desc *gdp;
3985	struct buffer_head *gdp_bh;
3986	int err;
3987	unsigned int i, already, changed = len;
3988
3989	KUNIT_STATIC_STUB_REDIRECT(ext4_mb_mark_context,
3990	handle, sb, state, group, blkoff, len,
3991	flags, ret_changed);
3992
3993	if (ret_changed)
3994	*ret_changed = 0;
3995	bitmap_bh = ext4_read_block_bitmap(sb, block_group: group);
3996	if (IS_ERR(ptr: bitmap_bh))
3997	return PTR_ERR(ptr: bitmap_bh);
3998
3999	if (handle) {
4000	BUFFER_TRACE(bitmap_bh, "getting write access");
4001	err = ext4_journal_get_write_access(handle, sb, bitmap_bh,
4002	EXT4_JTR_NONE);
4003	if (err)
4004	goto out_err;
4005	}
4006
4007	err = -EIO;
4008	gdp = ext4_get_group_desc(sb, block_group: group, bh: &gdp_bh);
4009	if (!gdp)
4010	goto out_err;
4011
4012	if (handle) {
4013	BUFFER_TRACE(gdp_bh, "get_write_access");
4014	err = ext4_journal_get_write_access(handle, sb, gdp_bh,
4015	EXT4_JTR_NONE);
4016	if (err)
4017	goto out_err;
4018	}
4019
4020	ext4_lock_group(sb, group);
4021	if (ext4_has_group_desc_csum(sb) &&
4022	(gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
4023	gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
4024	ext4_free_group_clusters_set(sb, bg: gdp,
4025	count: ext4_free_clusters_after_init(sb, block_group: group, gdp));
4026	}
4027
4028	if (flags & EXT4_MB_BITMAP_MARKED_CHECK) {
4029	already = 0;
4030	for (i = 0; i < len; i++)
4031	if (mb_test_bit(bit: blkoff + i, addr: bitmap_bh->b_data) ==
4032	state)
4033	already++;
4034	changed = len - already;
4035	}
4036
4037	if (state) {
4038	mb_set_bits(bm: bitmap_bh->b_data, cur: blkoff, len);
4039	ext4_free_group_clusters_set(sb, bg: gdp,
4040	count: ext4_free_group_clusters(sb, bg: gdp) - changed);
4041	} else {
4042	mb_clear_bits(bm: bitmap_bh->b_data, cur: blkoff, len);
4043	ext4_free_group_clusters_set(sb, bg: gdp,
4044	count: ext4_free_group_clusters(sb, bg: gdp) + changed);
4045	}
4046
4047	ext4_block_bitmap_csum_set(sb, gdp, bh: bitmap_bh);
4048	ext4_group_desc_csum_set(sb, group, gdp);
4049	ext4_unlock_group(sb, group);
4050	if (ret_changed)
4051	*ret_changed = changed;
4052
4053	if (sbi->s_log_groups_per_flex) {
4054	ext4_group_t flex_group = ext4_flex_group(sbi, block_group: group);
4055	struct flex_groups *fg = sbi_array_rcu_deref(sbi,
4056	s_flex_groups, flex_group);
4057
4058	if (state)
4059	atomic64_sub(i: changed, v: &fg->free_clusters);
4060	else
4061	atomic64_add(i: changed, v: &fg->free_clusters);
4062	}
4063
4064	err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
4065	if (err)
4066	goto out_err;
4067	err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
4068	if (err)
4069	goto out_err;
4070
4071	if (flags & EXT4_MB_SYNC_UPDATE) {
4072	sync_dirty_buffer(bh: bitmap_bh);
4073	sync_dirty_buffer(bh: gdp_bh);
4074	}
4075
4076	out_err:
4077	brelse(bh: bitmap_bh);
4078	return err;
4079	}
4080
4081	/*
4082	* Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps
4083	* Returns 0 if success or error code
4084	*/
4085	static noinline_for_stack int
4086	ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
4087	handle_t *handle, unsigned int reserv_clstrs)
4088	{
4089	struct ext4_group_desc *gdp;
4090	struct ext4_sb_info *sbi;
4091	struct super_block *sb;
4092	ext4_fsblk_t block;
4093	int err, len;
4094	int flags = 0;
4095	ext4_grpblk_t changed;
4096
4097	BUG_ON(ac->ac_status != AC_STATUS_FOUND);
4098	BUG_ON(ac->ac_b_ex.fe_len <= 0);
4099
4100	sb = ac->ac_sb;
4101	sbi = EXT4_SB(sb);
4102
4103	gdp = ext4_get_group_desc(sb, block_group: ac->ac_b_ex.fe_group, NULL);
4104	if (!gdp)
4105	return -EIO;
4106	ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group,
4107	ext4_free_group_clusters(sb, gdp));
4108
4109	block = ext4_grp_offs_to_block(sb, fex: &ac->ac_b_ex);
4110	len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
4111	if (!ext4_inode_block_valid(inode: ac->ac_inode, start_blk: block, count: len)) {
4112	ext4_error(sb, "Allocating blocks %llu-%llu which overlap "
4113	"fs metadata", block, block+len);
4114	/* File system mounted not to panic on error
4115	* Fix the bitmap and return EFSCORRUPTED
4116	* We leak some of the blocks here.
4117	*/
4118	err = ext4_mb_mark_context(handle, sb, state: true,
4119	group: ac->ac_b_ex.fe_group,
4120	blkoff: ac->ac_b_ex.fe_start,
4121	len: ac->ac_b_ex.fe_len,
4122	flags: 0, NULL);
4123	if (!err)
4124	err = -EFSCORRUPTED;
4125	return err;
4126	}
4127
4128	#ifdef AGGRESSIVE_CHECK
4129	flags |= EXT4_MB_BITMAP_MARKED_CHECK;
4130	#endif
4131	err = ext4_mb_mark_context(handle, sb, state: true, group: ac->ac_b_ex.fe_group,
4132	blkoff: ac->ac_b_ex.fe_start, len: ac->ac_b_ex.fe_len,
4133	flags, ret_changed: &changed);
4134
4135	if (err && changed == 0)
4136	return err;
4137
4138	#ifdef AGGRESSIVE_CHECK
4139	BUG_ON(changed != ac->ac_b_ex.fe_len);
4140	#endif
4141	percpu_counter_sub(fbc: &sbi->s_freeclusters_counter, amount: ac->ac_b_ex.fe_len);
4142	/*
4143	* Now reduce the dirty block count also. Should not go negative
4144	*/
4145	if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
4146	/* release all the reserved blocks if non delalloc */
4147	percpu_counter_sub(fbc: &sbi->s_dirtyclusters_counter,
4148	amount: reserv_clstrs);
4149
4150	return err;
4151	}
4152
4153	/*
4154	* Idempotent helper for Ext4 fast commit replay path to set the state of
4155	* blocks in bitmaps and update counters.
4156	*/
4157	void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
4158	int len, bool state)
4159	{
4160	struct ext4_sb_info *sbi = EXT4_SB(sb);
4161	ext4_group_t group;
4162	ext4_grpblk_t blkoff;
4163	int err = 0;
4164	unsigned int clen, thisgrp_len;
4165
4166	while (len > 0) {
4167	ext4_get_group_no_and_offset(sb, blocknr: block, blockgrpp: &group, offsetp: &blkoff);
4168
4169	/*
4170	* Check to see if we are freeing blocks across a group
4171	* boundary.
4172	* In case of flex_bg, this can happen that (block, len) may
4173	* span across more than one group. In that case we need to
4174	* get the corresponding group metadata to work with.
4175	* For this we have goto again loop.
4176	*/
4177	thisgrp_len = min_t(unsigned int, (unsigned int)len,
4178	EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
4179	clen = EXT4_NUM_B2C(sbi, thisgrp_len);
4180
4181	if (!ext4_sb_block_valid(sb, NULL, start_blk: block, count: thisgrp_len)) {
4182	ext4_error(sb, "Marking blocks in system zone - "
4183	"Block = %llu, len = %u",
4184	block, thisgrp_len);
4185	break;
4186	}
4187
4188	err = ext4_mb_mark_context(NULL, sb, state,
4189	group, blkoff, len: clen,
4190	EXT4_MB_BITMAP_MARKED_CHECK |
4191	EXT4_MB_SYNC_UPDATE,
4192	NULL);
4193	if (err)
4194	break;
4195
4196	block += thisgrp_len;
4197	len -= thisgrp_len;
4198	BUG_ON(len < 0);
4199	}
4200	}
4201
4202	/*
4203	* here we normalize request for locality group
4204	* Group request are normalized to s_mb_group_prealloc, which goes to
4205	* s_strip if we set the same via mount option.
4206	* s_mb_group_prealloc can be configured via
4207	* /sys/fs/ext4/<partition>/mb_group_prealloc
4208	*
4209	* XXX: should we try to preallocate more than the group has now?
4210	*/
4211	static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
4212	{
4213	struct super_block *sb = ac->ac_sb;
4214	struct ext4_locality_group *lg = ac->ac_lg;
4215
4216	BUG_ON(lg == NULL);
4217	ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
4218	mb_debug(sb, "goal %u blocks for locality group\n", ac->ac_g_ex.fe_len);
4219	}
4220
4221	/*
4222	* This function returns the next element to look at during inode
4223	* PA rbtree walk. We assume that we have held the inode PA rbtree lock
4224	* (ei->i_prealloc_lock)
4225	*
4226	* new_start The start of the range we want to compare
4227	* cur_start The existing start that we are comparing against
4228	* node The node of the rb_tree
4229	*/
4230	static inline struct rb_node*
4231	ext4_mb_pa_rb_next_iter(ext4_lblk_t new_start, ext4_lblk_t cur_start, struct rb_node *node)
4232	{
4233	if (new_start < cur_start)
4234	return node->rb_left;
4235	else
4236	return node->rb_right;
4237	}
4238
4239	static inline void
4240	ext4_mb_pa_assert_overlap(struct ext4_allocation_context *ac,
4241	ext4_lblk_t start, loff_t end)
4242	{
4243	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4244	struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4245	struct ext4_prealloc_space *tmp_pa;
4246	ext4_lblk_t tmp_pa_start;
4247	loff_t tmp_pa_end;
4248	struct rb_node *iter;
4249
4250	read_lock(&ei->i_prealloc_lock);
4251	for (iter = ei->i_prealloc_node.rb_node; iter;
4252	iter = ext4_mb_pa_rb_next_iter(new_start: start, cur_start: tmp_pa_start, node: iter)) {
4253	tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4254	pa_node.inode_node);
4255	tmp_pa_start = tmp_pa->pa_lstart;
4256	tmp_pa_end = pa_logical_end(sbi, pa: tmp_pa);
4257
4258	spin_lock(lock: &tmp_pa->pa_lock);
4259	if (tmp_pa->pa_deleted == 0)
4260	BUG_ON(!(start >= tmp_pa_end || end <= tmp_pa_start));
4261	spin_unlock(lock: &tmp_pa->pa_lock);
4262	}
4263	read_unlock(&ei->i_prealloc_lock);
4264	}
4265
4266	/*
4267	* Given an allocation context "ac" and a range "start", "end", check
4268	* and adjust boundaries if the range overlaps with any of the existing
4269	* preallocatoins stored in the corresponding inode of the allocation context.
4270	*
4271	* Parameters:
4272	* ac allocation context
4273	* start start of the new range
4274	* end end of the new range
4275	*/
4276	static inline void
4277	ext4_mb_pa_adjust_overlap(struct ext4_allocation_context *ac,
4278	ext4_lblk_t *start, loff_t *end)
4279	{
4280	struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4281	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4282	struct ext4_prealloc_space *tmp_pa = NULL, *left_pa = NULL, *right_pa = NULL;
4283	struct rb_node *iter;
4284	ext4_lblk_t new_start, tmp_pa_start, right_pa_start = -1;
4285	loff_t new_end, tmp_pa_end, left_pa_end = -1;
4286
4287	new_start = *start;
4288	new_end = *end;
4289
4290	/*
4291	* Adjust the normalized range so that it doesn't overlap with any
4292	* existing preallocated blocks(PAs). Make sure to hold the rbtree lock
4293	* so it doesn't change underneath us.
4294	*/
4295	read_lock(&ei->i_prealloc_lock);
4296
4297	/* Step 1: find any one immediate neighboring PA of the normalized range */
4298	for (iter = ei->i_prealloc_node.rb_node; iter;
4299	iter = ext4_mb_pa_rb_next_iter(new_start: ac->ac_o_ex.fe_logical,
4300	cur_start: tmp_pa_start, node: iter)) {
4301	tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4302	pa_node.inode_node);
4303	tmp_pa_start = tmp_pa->pa_lstart;
4304	tmp_pa_end = pa_logical_end(sbi, pa: tmp_pa);
4305
4306	/* PA must not overlap original request */
4307	spin_lock(lock: &tmp_pa->pa_lock);
4308	if (tmp_pa->pa_deleted == 0)
4309	BUG_ON(!(ac->ac_o_ex.fe_logical >= tmp_pa_end ||
4310	ac->ac_o_ex.fe_logical < tmp_pa_start));
4311	spin_unlock(lock: &tmp_pa->pa_lock);
4312	}
4313
4314	/*
4315	* Step 2: check if the found PA is left or right neighbor and
4316	* get the other neighbor
4317	*/
4318	if (tmp_pa) {
4319	if (tmp_pa->pa_lstart < ac->ac_o_ex.fe_logical) {
4320	struct rb_node *tmp;
4321
4322	left_pa = tmp_pa;
4323	tmp = rb_next(&left_pa->pa_node.inode_node);
4324	if (tmp) {
4325	right_pa = rb_entry(tmp,
4326	struct ext4_prealloc_space,
4327	pa_node.inode_node);
4328	}
4329	} else {
4330	struct rb_node *tmp;
4331
4332	right_pa = tmp_pa;
4333	tmp = rb_prev(&right_pa->pa_node.inode_node);
4334	if (tmp) {
4335	left_pa = rb_entry(tmp,
4336	struct ext4_prealloc_space,
4337	pa_node.inode_node);
4338	}
4339	}
4340	}
4341
4342	/* Step 3: get the non deleted neighbors */
4343	if (left_pa) {
4344	for (iter = &left_pa->pa_node.inode_node;;
4345	iter = rb_prev(iter)) {
4346	if (!iter) {
4347	left_pa = NULL;
4348	break;
4349	}
4350
4351	tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4352	pa_node.inode_node);
4353	left_pa = tmp_pa;
4354	spin_lock(lock: &tmp_pa->pa_lock);
4355	if (tmp_pa->pa_deleted == 0) {
4356	spin_unlock(lock: &tmp_pa->pa_lock);
4357	break;
4358	}
4359	spin_unlock(lock: &tmp_pa->pa_lock);
4360	}
4361	}
4362
4363	if (right_pa) {
4364	for (iter = &right_pa->pa_node.inode_node;;
4365	iter = rb_next(iter)) {
4366	if (!iter) {
4367	right_pa = NULL;
4368	break;
4369	}
4370
4371	tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4372	pa_node.inode_node);
4373	right_pa = tmp_pa;
4374	spin_lock(lock: &tmp_pa->pa_lock);
4375	if (tmp_pa->pa_deleted == 0) {
4376	spin_unlock(lock: &tmp_pa->pa_lock);
4377	break;
4378	}
4379	spin_unlock(lock: &tmp_pa->pa_lock);
4380	}
4381	}
4382
4383	if (left_pa) {
4384	left_pa_end = pa_logical_end(sbi, pa: left_pa);
4385	BUG_ON(left_pa_end > ac->ac_o_ex.fe_logical);
4386	}
4387
4388	if (right_pa) {
4389	right_pa_start = right_pa->pa_lstart;
4390	BUG_ON(right_pa_start <= ac->ac_o_ex.fe_logical);
4391	}
4392
4393	/* Step 4: trim our normalized range to not overlap with the neighbors */
4394	if (left_pa) {
4395	if (left_pa_end > new_start)
4396	new_start = left_pa_end;
4397	}
4398
4399	if (right_pa) {
4400	if (right_pa_start < new_end)
4401	new_end = right_pa_start;
4402	}
4403	read_unlock(&ei->i_prealloc_lock);
4404
4405	/* XXX: extra loop to check we really don't overlap preallocations */
4406	ext4_mb_pa_assert_overlap(ac, start: new_start, end: new_end);
4407
4408	*start = new_start;
4409	*end = new_end;
4410	}
4411
4412	/*
4413	* Normalization means making request better in terms of
4414	* size and alignment
4415	*/
4416	static noinline_for_stack void
4417	ext4_mb_normalize_request(struct ext4_allocation_context *ac,
4418	struct ext4_allocation_request *ar)
4419	{
4420	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4421	struct ext4_super_block *es = sbi->s_es;
4422	int bsbits, max;
4423	loff_t size, start_off, end;
4424	loff_t orig_size __maybe_unused;
4425	ext4_lblk_t start;
4426
4427	/* do normalize only data requests, metadata requests
4428	do not need preallocation */
4429	if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4430	return;
4431
4432	/* sometime caller may want exact blocks */
4433	if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4434	return;
4435
4436	/* caller may indicate that preallocation isn't
4437	* required (it's a tail, for example) */
4438	if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
4439	return;
4440
4441	if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
4442	ext4_mb_normalize_group_request(ac);
4443	return ;
4444	}
4445
4446	bsbits = ac->ac_sb->s_blocksize_bits;
4447
4448	/* first, let's learn actual file size
4449	* given current request is allocated */
4450	size = extent_logical_end(sbi, fex: &ac->ac_o_ex);
4451	size = size << bsbits;
4452	if (size < i_size_read(inode: ac->ac_inode))
4453	size = i_size_read(inode: ac->ac_inode);
4454	orig_size = size;
4455
4456	/* max size of free chunks */
4457	max = 2 << bsbits;
4458
4459	#define NRL_CHECK_SIZE(req, size, max, chunk_size) \
4460	(req <= (size) || max <= (chunk_size))
4461
4462	/* first, try to predict filesize */
4463	/* XXX: should this table be tunable? */
4464	start_off = 0;
4465	if (size <= 16 * 1024) {
4466	size = 16 * 1024;
4467	} else if (size <= 32 * 1024) {
4468	size = 32 * 1024;
4469	} else if (size <= 64 * 1024) {
4470	size = 64 * 1024;
4471	} else if (size <= 128 * 1024) {
4472	size = 128 * 1024;
4473	} else if (size <= 256 * 1024) {
4474	size = 256 * 1024;
4475	} else if (size <= 512 * 1024) {
4476	size = 512 * 1024;
4477	} else if (size <= 1024 * 1024) {
4478	size = 1024 * 1024;
4479	} else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
4480	start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4481	(21 - bsbits)) << 21;
4482	size = 2 * 1024 * 1024;
4483	} else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
4484	start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4485	(22 - bsbits)) << 22;
4486	size = 4 * 1024 * 1024;
4487	} else if (NRL_CHECK_SIZE(EXT4_C2B(sbi, ac->ac_o_ex.fe_len),
4488	(8<<20)>>bsbits, max, 8 * 1024)) {
4489	start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
4490	(23 - bsbits)) << 23;
4491	size = 8 * 1024 * 1024;
4492	} else {
4493	start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
4494	size = (loff_t) EXT4_C2B(sbi,
4495	ac->ac_o_ex.fe_len) << bsbits;
4496	}
4497	size = size >> bsbits;
4498	start = start_off >> bsbits;
4499
4500	/*
4501	* For tiny groups (smaller than 8MB) the chosen allocation
4502	* alignment may be larger than group size. Make sure the
4503	* alignment does not move allocation to a different group which
4504	* makes mballoc fail assertions later.
4505	*/
4506	start = max(start, rounddown(ac->ac_o_ex.fe_logical,
4507	(ext4_lblk_t)EXT4_BLOCKS_PER_GROUP(ac->ac_sb)));
4508
4509	/* avoid unnecessary preallocation that may trigger assertions */
4510	if (start + size > EXT_MAX_BLOCKS)
4511	size = EXT_MAX_BLOCKS - start;
4512
4513	/* don't cover already allocated blocks in selected range */
4514	if (ar->pleft && start <= ar->lleft) {
4515	size -= ar->lleft + 1 - start;
4516	start = ar->lleft + 1;
4517	}
4518	if (ar->pright && start + size - 1 >= ar->lright)
4519	size -= start + size - ar->lright;
4520
4521	/*
4522	* Trim allocation request for filesystems with artificially small
4523	* groups.
4524	*/
4525	if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
4526	size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
4527
4528	end = start + size;
4529
4530	ext4_mb_pa_adjust_overlap(ac, start: &start, end: &end);
4531
4532	size = end - start;
4533
4534	/*
4535	* In this function "start" and "size" are normalized for better
4536	* alignment and length such that we could preallocate more blocks.
4537	* This normalization is done such that original request of
4538	* ac->ac_o_ex.fe_logical & fe_len should always lie within "start" and
4539	* "size" boundaries.
4540	* (Note fe_len can be relaxed since FS block allocation API does not
4541	* provide gurantee on number of contiguous blocks allocation since that
4542	* depends upon free space left, etc).
4543	* In case of inode pa, later we use the allocated blocks
4544	* [pa_pstart + fe_logical - pa_lstart, fe_len/size] from the preallocated
4545	* range of goal/best blocks [start, size] to put it at the
4546	* ac_o_ex.fe_logical extent of this inode.
4547	* (See ext4_mb_use_inode_pa() for more details)
4548	*/
4549	if (start + size <= ac->ac_o_ex.fe_logical ||
4550	start > ac->ac_o_ex.fe_logical) {
4551	ext4_msg(ac->ac_sb, KERN_ERR,
4552	"start %lu, size %lu, fe_logical %lu",
4553	(unsigned long) start, (unsigned long) size,
4554	(unsigned long) ac->ac_o_ex.fe_logical);
4555	BUG();
4556	}
4557	BUG_ON(size <= 0 || size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
4558
4559	/* now prepare goal request */
4560
4561	/* XXX: is it better to align blocks WRT to logical
4562	* placement or satisfy big request as is */
4563	ac->ac_g_ex.fe_logical = start;
4564	ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size);
4565	ac->ac_orig_goal_len = ac->ac_g_ex.fe_len;
4566
4567	/* define goal start in order to merge */
4568	if (ar->pright && (ar->lright == (start + size)) &&
4569	ar->pright >= size &&
4570	ar->pright - size >= le32_to_cpu(es->s_first_data_block)) {
4571	/* merge to the right */
4572	ext4_get_group_no_and_offset(sb: ac->ac_sb, blocknr: ar->pright - size,
4573	blockgrpp: &ac->ac_g_ex.fe_group,
4574	offsetp: &ac->ac_g_ex.fe_start);
4575	ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
4576	}
4577	if (ar->pleft && (ar->lleft + 1 == start) &&
4578	ar->pleft + 1 < ext4_blocks_count(es)) {
4579	/* merge to the left */
4580	ext4_get_group_no_and_offset(sb: ac->ac_sb, blocknr: ar->pleft + 1,
4581	blockgrpp: &ac->ac_g_ex.fe_group,
4582	offsetp: &ac->ac_g_ex.fe_start);
4583	ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
4584	}
4585
4586	mb_debug(ac->ac_sb, "goal: %lld(was %lld) blocks at %u\n", size,
4587	orig_size, start);
4588	}
4589
4590	static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
4591	{
4592	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4593
4594	if (sbi->s_mb_stats && ac->ac_g_ex.fe_len >= 1) {
4595	atomic_inc(v: &sbi->s_bal_reqs);
4596	atomic_add(i: ac->ac_b_ex.fe_len, v: &sbi->s_bal_allocated);
4597	if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
4598	atomic_inc(v: &sbi->s_bal_success);
4599
4600	atomic_add(i: ac->ac_found, v: &sbi->s_bal_ex_scanned);
4601	for (int i=0; i<EXT4_MB_NUM_CRS; i++) {
4602	atomic_add(i: ac->ac_cX_found[i], v: &sbi->s_bal_cX_ex_scanned[i]);
4603	}
4604
4605	atomic_add(i: ac->ac_groups_scanned, v: &sbi->s_bal_groups_scanned);
4606	if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
4607	ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
4608	atomic_inc(v: &sbi->s_bal_goals);
4609	/* did we allocate as much as normalizer originally wanted? */
4610	if (ac->ac_f_ex.fe_len == ac->ac_orig_goal_len)
4611	atomic_inc(v: &sbi->s_bal_len_goals);
4612
4613	if (ac->ac_found > sbi->s_mb_max_to_scan)
4614	atomic_inc(v: &sbi->s_bal_breaks);
4615	}
4616
4617	if (ac->ac_op == EXT4_MB_HISTORY_ALLOC)
4618	trace_ext4_mballoc_alloc(ac);
4619	else
4620	trace_ext4_mballoc_prealloc(ac);
4621	}
4622
4623	/*
4624	* Called on failure; free up any blocks from the inode PA for this
4625	* context. We don't need this for MB_GROUP_PA because we only change
4626	* pa_free in ext4_mb_release_context(), but on failure, we've already
4627	* zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed.
4628	*/
4629	static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac)
4630	{
4631	struct ext4_prealloc_space *pa = ac->ac_pa;
4632	struct ext4_buddy e4b;
4633	int err;
4634
4635	if (pa == NULL) {
4636	if (ac->ac_f_ex.fe_len == 0)
4637	return;
4638	err = ext4_mb_load_buddy(sb: ac->ac_sb, group: ac->ac_f_ex.fe_group, e4b: &e4b);
4639	if (WARN_RATELIMIT(err,
4640	"ext4: mb_load_buddy failed (%d)", err))
4641	/*
4642	* This should never happen since we pin the
4643	* pages in the ext4_allocation_context so
4644	* ext4_mb_load_buddy() should never fail.
4645	*/
4646	return;
4647	ext4_lock_group(sb: ac->ac_sb, group: ac->ac_f_ex.fe_group);
4648	mb_free_blocks(inode: ac->ac_inode, e4b: &e4b, first: ac->ac_f_ex.fe_start,
4649	count: ac->ac_f_ex.fe_len);
4650	ext4_unlock_group(sb: ac->ac_sb, group: ac->ac_f_ex.fe_group);
4651	ext4_mb_unload_buddy(e4b: &e4b);
4652	return;
4653	}
4654	if (pa->pa_type == MB_INODE_PA) {
4655	spin_lock(lock: &pa->pa_lock);
4656	pa->pa_free += ac->ac_b_ex.fe_len;
4657	spin_unlock(lock: &pa->pa_lock);
4658	}
4659	}
4660
4661	/*
4662	* use blocks preallocated to inode
4663	*/
4664	static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
4665	struct ext4_prealloc_space *pa)
4666	{
4667	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4668	ext4_fsblk_t start;
4669	ext4_fsblk_t end;
4670	int len;
4671
4672	/* found preallocated blocks, use them */
4673	start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
4674	end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),
4675	start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len));
4676	len = EXT4_NUM_B2C(sbi, end - start);
4677	ext4_get_group_no_and_offset(sb: ac->ac_sb, blocknr: start, blockgrpp: &ac->ac_b_ex.fe_group,
4678	offsetp: &ac->ac_b_ex.fe_start);
4679	ac->ac_b_ex.fe_len = len;
4680	ac->ac_status = AC_STATUS_FOUND;
4681	ac->ac_pa = pa;
4682
4683	BUG_ON(start < pa->pa_pstart);
4684	BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));
4685	BUG_ON(pa->pa_free < len);
4686	BUG_ON(ac->ac_b_ex.fe_len <= 0);
4687	pa->pa_free -= len;
4688
4689	mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa);
4690	}
4691
4692	/*
4693	* use blocks preallocated to locality group
4694	*/
4695	static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
4696	struct ext4_prealloc_space *pa)
4697	{
4698	unsigned int len = ac->ac_o_ex.fe_len;
4699
4700	ext4_get_group_no_and_offset(sb: ac->ac_sb, blocknr: pa->pa_pstart,
4701	blockgrpp: &ac->ac_b_ex.fe_group,
4702	offsetp: &ac->ac_b_ex.fe_start);
4703	ac->ac_b_ex.fe_len = len;
4704	ac->ac_status = AC_STATUS_FOUND;
4705	ac->ac_pa = pa;
4706
4707	/* we don't correct pa_pstart or pa_len here to avoid
4708	* possible race when the group is being loaded concurrently
4709	* instead we correct pa later, after blocks are marked
4710	* in on-disk bitmap -- see ext4_mb_release_context()
4711	* Other CPUs are prevented from allocating from this pa by lg_mutex
4712	*/
4713	mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n",
4714	pa->pa_lstart, len, pa);
4715	}
4716
4717	/*
4718	* Return the prealloc space that have minimal distance
4719	* from the goal block. @cpa is the prealloc
4720	* space that is having currently known minimal distance
4721	* from the goal block.
4722	*/
4723	static struct ext4_prealloc_space *
4724	ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
4725	struct ext4_prealloc_space *pa,
4726	struct ext4_prealloc_space *cpa)
4727	{
4728	ext4_fsblk_t cur_distance, new_distance;
4729
4730	if (cpa == NULL) {
4731	atomic_inc(v: &pa->pa_count);
4732	return pa;
4733	}
4734	cur_distance = abs(goal_block - cpa->pa_pstart);
4735	new_distance = abs(goal_block - pa->pa_pstart);
4736
4737	if (cur_distance <= new_distance)
4738	return cpa;
4739
4740	/* drop the previous reference */
4741	atomic_dec(v: &cpa->pa_count);
4742	atomic_inc(v: &pa->pa_count);
4743	return pa;
4744	}
4745
4746	/*
4747	* check if found pa meets EXT4_MB_HINT_GOAL_ONLY
4748	*/
4749	static bool
4750	ext4_mb_pa_goal_check(struct ext4_allocation_context *ac,
4751	struct ext4_prealloc_space *pa)
4752	{
4753	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4754	ext4_fsblk_t start;
4755
4756	if (likely(!(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)))
4757	return true;
4758
4759	/*
4760	* If EXT4_MB_HINT_GOAL_ONLY is set, ac_g_ex will not be adjusted
4761	* in ext4_mb_normalize_request and will keep same with ac_o_ex
4762	* from ext4_mb_initialize_context. Choose ac_g_ex here to keep
4763	* consistent with ext4_mb_find_by_goal.
4764	*/
4765	start = pa->pa_pstart +
4766	(ac->ac_g_ex.fe_logical - pa->pa_lstart);
4767	if (ext4_grp_offs_to_block(sb: ac->ac_sb, fex: &ac->ac_g_ex) != start)
4768	return false;
4769
4770	if (ac->ac_g_ex.fe_len > pa->pa_len -
4771	EXT4_B2C(sbi, ac->ac_g_ex.fe_logical - pa->pa_lstart))
4772	return false;
4773
4774	return true;
4775	}
4776
4777	/*
4778	* search goal blocks in preallocated space
4779	*/
4780	static noinline_for_stack bool
4781	ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
4782	{
4783	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
4784	int order, i;
4785	struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
4786	struct ext4_locality_group *lg;
4787	struct ext4_prealloc_space *tmp_pa = NULL, *cpa = NULL;
4788	struct rb_node *iter;
4789	ext4_fsblk_t goal_block;
4790
4791	/* only data can be preallocated */
4792	if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4793	return false;
4794
4795	/*
4796	* first, try per-file preallocation by searching the inode pa rbtree.
4797	*
4798	* Here, we can't do a direct traversal of the tree because
4799	* ext4_mb_discard_group_preallocation() can paralelly mark the pa
4800	* deleted and that can cause direct traversal to skip some entries.
4801	*/
4802	read_lock(&ei->i_prealloc_lock);
4803
4804	if (RB_EMPTY_ROOT(&ei->i_prealloc_node)) {
4805	goto try_group_pa;
4806	}
4807
4808	/*
4809	* Step 1: Find a pa with logical start immediately adjacent to the
4810	* original logical start. This could be on the left or right.
4811	*
4812	* (tmp_pa->pa_lstart never changes so we can skip locking for it).
4813	*/
4814	for (iter = ei->i_prealloc_node.rb_node; iter;
4815	iter = ext4_mb_pa_rb_next_iter(new_start: ac->ac_o_ex.fe_logical,
4816	cur_start: tmp_pa->pa_lstart, node: iter)) {
4817	tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4818	pa_node.inode_node);
4819	}
4820
4821	/*
4822	* Step 2: The adjacent pa might be to the right of logical start, find
4823	* the left adjacent pa. After this step we'd have a valid tmp_pa whose
4824	* logical start is towards the left of original request's logical start
4825	*/
4826	if (tmp_pa->pa_lstart > ac->ac_o_ex.fe_logical) {
4827	struct rb_node *tmp;
4828	tmp = rb_prev(&tmp_pa->pa_node.inode_node);
4829
4830	if (tmp) {
4831	tmp_pa = rb_entry(tmp, struct ext4_prealloc_space,
4832	pa_node.inode_node);
4833	} else {
4834	/*
4835	* If there is no adjacent pa to the left then finding
4836	* an overlapping pa is not possible hence stop searching
4837	* inode pa tree
4838	*/
4839	goto try_group_pa;
4840	}
4841	}
4842
4843	BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical));
4844
4845	/*
4846	* Step 3: If the left adjacent pa is deleted, keep moving left to find
4847	* the first non deleted adjacent pa. After this step we should have a
4848	* valid tmp_pa which is guaranteed to be non deleted.
4849	*/
4850	for (iter = &tmp_pa->pa_node.inode_node;; iter = rb_prev(iter)) {
4851	if (!iter) {
4852	/*
4853	* no non deleted left adjacent pa, so stop searching
4854	* inode pa tree
4855	*/
4856	goto try_group_pa;
4857	}
4858	tmp_pa = rb_entry(iter, struct ext4_prealloc_space,
4859	pa_node.inode_node);
4860	spin_lock(lock: &tmp_pa->pa_lock);
4861	if (tmp_pa->pa_deleted == 0) {
4862	/*
4863	* We will keep holding the pa_lock from
4864	* this point on because we don't want group discard
4865	* to delete this pa underneath us. Since group
4866	* discard is anyways an ENOSPC operation it
4867	* should be okay for it to wait a few more cycles.
4868	*/
4869	break;
4870	} else {
4871	spin_unlock(lock: &tmp_pa->pa_lock);
4872	}
4873	}
4874
4875	BUG_ON(!(tmp_pa && tmp_pa->pa_lstart <= ac->ac_o_ex.fe_logical));
4876	BUG_ON(tmp_pa->pa_deleted == 1);
4877
4878	/*
4879	* Step 4: We now have the non deleted left adjacent pa. Only this
4880	* pa can possibly satisfy the request hence check if it overlaps
4881	* original logical start and stop searching if it doesn't.
4882	*/
4883	if (ac->ac_o_ex.fe_logical >= pa_logical_end(sbi, pa: tmp_pa)) {
4884	spin_unlock(lock: &tmp_pa->pa_lock);
4885	goto try_group_pa;
4886	}
4887
4888	/* non-extent files can't have physical blocks past 2^32 */
4889	if (!(ext4_test_inode_flag(inode: ac->ac_inode, bit: EXT4_INODE_EXTENTS)) &&
4890	(tmp_pa->pa_pstart + EXT4_C2B(sbi, tmp_pa->pa_len) >
4891	EXT4_MAX_BLOCK_FILE_PHYS)) {
4892	/*
4893	* Since PAs don't overlap, we won't find any other PA to
4894	* satisfy this.
4895	*/
4896	spin_unlock(lock: &tmp_pa->pa_lock);
4897	goto try_group_pa;
4898	}
4899
4900	if (tmp_pa->pa_free && likely(ext4_mb_pa_goal_check(ac, tmp_pa))) {
4901	atomic_inc(v: &tmp_pa->pa_count);
4902	ext4_mb_use_inode_pa(ac, pa: tmp_pa);
4903	spin_unlock(lock: &tmp_pa->pa_lock);
4904	read_unlock(&ei->i_prealloc_lock);
4905	return true;
4906	} else {
4907	/*
4908	* We found a valid overlapping pa but couldn't use it because
4909	* it had no free blocks. This should ideally never happen
4910	* because:
4911	*
4912	* 1. When a new inode pa is added to rbtree it must have
4913	* pa_free > 0 since otherwise we won't actually need
4914	* preallocation.
4915	*
4916	* 2. An inode pa that is in the rbtree can only have it's
4917	* pa_free become zero when another thread calls:
4918	* ext4_mb_new_blocks
4919	* ext4_mb_use_preallocated
4920	* ext4_mb_use_inode_pa
4921	*
4922	* 3. Further, after the above calls make pa_free == 0, we will
4923	* immediately remove it from the rbtree in:
4924	* ext4_mb_new_blocks
4925	* ext4_mb_release_context
4926	* ext4_mb_put_pa
4927	*
4928	* 4. Since the pa_free becoming 0 and pa_free getting removed
4929	* from tree both happen in ext4_mb_new_blocks, which is always
4930	* called with i_data_sem held for data allocations, we can be
4931	* sure that another process will never see a pa in rbtree with
4932	* pa_free == 0.
4933	*/
4934	WARN_ON_ONCE(tmp_pa->pa_free == 0);
4935	}
4936	spin_unlock(lock: &tmp_pa->pa_lock);
4937	try_group_pa:
4938	read_unlock(&ei->i_prealloc_lock);
4939
4940	/* can we use group allocation? */
4941	if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
4942	return false;
4943
4944	/* inode may have no locality group for some reason */
4945	lg = ac->ac_lg;
4946	if (lg == NULL)
4947	return false;
4948	order = fls(x: ac->ac_o_ex.fe_len) - 1;
4949	if (order > PREALLOC_TB_SIZE - 1)
4950	/* The max size of hash table is PREALLOC_TB_SIZE */
4951	order = PREALLOC_TB_SIZE - 1;
4952
4953	goal_block = ext4_grp_offs_to_block(sb: ac->ac_sb, fex: &ac->ac_g_ex);
4954	/*
4955	* search for the prealloc space that is having
4956	* minimal distance from the goal block.
4957	*/
4958	for (i = order; i < PREALLOC_TB_SIZE; i++) {
4959	rcu_read_lock();
4960	list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[i],
4961	pa_node.lg_list) {
4962	spin_lock(lock: &tmp_pa->pa_lock);
4963	if (tmp_pa->pa_deleted == 0 &&
4964	tmp_pa->pa_free >= ac->ac_o_ex.fe_len) {
4965
4966	cpa = ext4_mb_check_group_pa(goal_block,
4967	pa: tmp_pa, cpa);
4968	}
4969	spin_unlock(lock: &tmp_pa->pa_lock);
4970	}
4971	rcu_read_unlock();
4972	}
4973	if (cpa) {
4974	ext4_mb_use_group_pa(ac, pa: cpa);
4975	return true;
4976	}
4977	return false;
4978	}
4979
4980	/*
4981	* the function goes through all preallocation in this group and marks them
4982	* used in in-core bitmap. buddy must be generated from this bitmap
4983	* Need to be called with ext4 group lock held
4984	*/
4985	static noinline_for_stack
4986	void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
4987	ext4_group_t group)
4988	{
4989	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
4990	struct ext4_prealloc_space *pa;
4991	struct list_head *cur;
4992	ext4_group_t groupnr;
4993	ext4_grpblk_t start;
4994	int preallocated = 0;
4995	int len;
4996
4997	if (!grp)
4998	return;
4999
5000	/* all form of preallocation discards first load group,
5001	* so the only competing code is preallocation use.
5002	* we don't need any locking here
5003	* notice we do NOT ignore preallocations with pa_deleted
5004	* otherwise we could leave used blocks available for
5005	* allocation in buddy when concurrent ext4_mb_put_pa()
5006	* is dropping preallocation
5007	*/
5008	list_for_each(cur, &grp->bb_prealloc_list) {
5009	pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
5010	spin_lock(lock: &pa->pa_lock);
5011	ext4_get_group_no_and_offset(sb, blocknr: pa->pa_pstart,
5012	blockgrpp: &groupnr, offsetp: &start);
5013	len = pa->pa_len;
5014	spin_unlock(lock: &pa->pa_lock);
5015	if (unlikely(len == 0))
5016	continue;
5017	BUG_ON(groupnr != group);
5018	mb_set_bits(bm: bitmap, cur: start, len);
5019	preallocated += len;
5020	}
5021	mb_debug(sb, "preallocated %d for group %u\n", preallocated, group);
5022	}
5023
5024	static void ext4_mb_mark_pa_deleted(struct super_block *sb,
5025	struct ext4_prealloc_space *pa)
5026	{
5027	struct ext4_inode_info *ei;
5028
5029	if (pa->pa_deleted) {
5030	ext4_warning(sb, "deleted pa, type:%d, pblk:%llu, lblk:%u, len:%d\n",
5031	pa->pa_type, pa->pa_pstart, pa->pa_lstart,
5032	pa->pa_len);
5033	return;
5034	}
5035
5036	pa->pa_deleted = 1;
5037
5038	if (pa->pa_type == MB_INODE_PA) {
5039	ei = EXT4_I(pa->pa_inode);
5040	atomic_dec(v: &ei->i_prealloc_active);
5041	}
5042	}
5043
5044	static inline void ext4_mb_pa_free(struct ext4_prealloc_space *pa)
5045	{
5046	BUG_ON(!pa);
5047	BUG_ON(atomic_read(&pa->pa_count));
5048	BUG_ON(pa->pa_deleted == 0);
5049	kmem_cache_free(s: ext4_pspace_cachep, objp: pa);
5050	}
5051
5052	static void ext4_mb_pa_callback(struct rcu_head *head)
5053	{
5054	struct ext4_prealloc_space *pa;
5055
5056	pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
5057	ext4_mb_pa_free(pa);
5058	}
5059
5060	/*
5061	* drops a reference to preallocated space descriptor
5062	* if this was the last reference and the space is consumed
5063	*/
5064	static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
5065	struct super_block *sb, struct ext4_prealloc_space *pa)
5066	{
5067	ext4_group_t grp;
5068	ext4_fsblk_t grp_blk;
5069	struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
5070
5071	/* in this short window concurrent discard can set pa_deleted */
5072	spin_lock(lock: &pa->pa_lock);
5073	if (!atomic_dec_and_test(v: &pa->pa_count) || pa->pa_free != 0) {
5074	spin_unlock(lock: &pa->pa_lock);
5075	return;
5076	}
5077
5078	if (pa->pa_deleted == 1) {
5079	spin_unlock(lock: &pa->pa_lock);
5080	return;
5081	}
5082
5083	ext4_mb_mark_pa_deleted(sb, pa);
5084	spin_unlock(lock: &pa->pa_lock);
5085
5086	grp_blk = pa->pa_pstart;
5087	/*
5088	* If doing group-based preallocation, pa_pstart may be in the
5089	* next group when pa is used up
5090	*/
5091	if (pa->pa_type == MB_GROUP_PA)
5092	grp_blk--;
5093
5094	grp = ext4_get_group_number(sb, block: grp_blk);
5095
5096	/*
5097	* possible race:
5098	*
5099	* P1 (buddy init) P2 (regular allocation)
5100	* find block B in PA
5101	* copy on-disk bitmap to buddy
5102	* mark B in on-disk bitmap
5103	* drop PA from group
5104	* mark all PAs in buddy
5105	*
5106	* thus, P1 initializes buddy with B available. to prevent this
5107	* we make "copy" and "mark all PAs" atomic and serialize "drop PA"
5108	* against that pair
5109	*/
5110	ext4_lock_group(sb, group: grp);
5111	list_del(entry: &pa->pa_group_list);
5112	ext4_unlock_group(sb, group: grp);
5113
5114	if (pa->pa_type == MB_INODE_PA) {
5115	write_lock(pa->pa_node_lock.inode_lock);
5116	rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
5117	write_unlock(pa->pa_node_lock.inode_lock);
5118	ext4_mb_pa_free(pa);
5119	} else {
5120	spin_lock(lock: pa->pa_node_lock.lg_lock);
5121	list_del_rcu(entry: &pa->pa_node.lg_list);
5122	spin_unlock(lock: pa->pa_node_lock.lg_lock);
5123	call_rcu(head: &(pa)->u.pa_rcu, func: ext4_mb_pa_callback);
5124	}
5125	}
5126
5127	static void ext4_mb_pa_rb_insert(struct rb_root *root, struct rb_node *new)
5128	{
5129	struct rb_node **iter = &root->rb_node, *parent = NULL;
5130	struct ext4_prealloc_space *iter_pa, *new_pa;
5131	ext4_lblk_t iter_start, new_start;
5132
5133	while (*iter) {
5134	iter_pa = rb_entry(*iter, struct ext4_prealloc_space,
5135	pa_node.inode_node);
5136	new_pa = rb_entry(new, struct ext4_prealloc_space,
5137	pa_node.inode_node);
5138	iter_start = iter_pa->pa_lstart;
5139	new_start = new_pa->pa_lstart;
5140
5141	parent = *iter;
5142	if (new_start < iter_start)
5143	iter = &((*iter)->rb_left);
5144	else
5145	iter = &((*iter)->rb_right);
5146	}
5147
5148	rb_link_node(node: new, parent, rb_link: iter);
5149	rb_insert_color(new, root);
5150	}
5151
5152	/*
5153	* creates new preallocated space for given inode
5154	*/
5155	static noinline_for_stack void
5156	ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
5157	{
5158	struct super_block *sb = ac->ac_sb;
5159	struct ext4_sb_info *sbi = EXT4_SB(sb);
5160	struct ext4_prealloc_space *pa;
5161	struct ext4_group_info *grp;
5162	struct ext4_inode_info *ei;
5163
5164	/* preallocate only when found space is larger then requested */
5165	BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
5166	BUG_ON(ac->ac_status != AC_STATUS_FOUND);
5167	BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
5168	BUG_ON(ac->ac_pa == NULL);
5169
5170	pa = ac->ac_pa;
5171
5172	if (ac->ac_b_ex.fe_len < ac->ac_orig_goal_len) {
5173	struct ext4_free_extent ex = {
5174	.fe_logical = ac->ac_g_ex.fe_logical,
5175	.fe_len = ac->ac_orig_goal_len,
5176	};
5177	loff_t orig_goal_end = extent_logical_end(sbi, fex: &ex);
5178	loff_t o_ex_end = extent_logical_end(sbi, fex: &ac->ac_o_ex);
5179
5180	/*
5181	* We can't allocate as much as normalizer wants, so we try
5182	* to get proper lstart to cover the original request, except
5183	* when the goal doesn't cover the original request as below:
5184	*
5185	* orig_ex:2045/2055(10), isize:8417280 -> normalized:0/2048
5186	* best_ex:0/200(200) -> adjusted: 1848/2048(200)
5187	*/
5188	BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
5189	BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
5190
5191	/*
5192	* Use the below logic for adjusting best extent as it keeps
5193	* fragmentation in check while ensuring logical range of best
5194	* extent doesn't overflow out of goal extent:
5195	*
5196	* 1. Check if best ex can be kept at end of goal (before
5197	* cr_best_avail trimmed it) and still cover original start
5198	* 2. Else, check if best ex can be kept at start of goal and
5199	* still cover original end
5200	* 3. Else, keep the best ex at start of original request.
5201	*/
5202	ex.fe_len = ac->ac_b_ex.fe_len;
5203
5204	ex.fe_logical = orig_goal_end - EXT4_C2B(sbi, ex.fe_len);
5205	if (ac->ac_o_ex.fe_logical >= ex.fe_logical)
5206	goto adjust_bex;
5207
5208	ex.fe_logical = ac->ac_g_ex.fe_logical;
5209	if (o_ex_end <= extent_logical_end(sbi, fex: &ex))
5210	goto adjust_bex;
5211
5212	ex.fe_logical = ac->ac_o_ex.fe_logical;
5213	adjust_bex:
5214	ac->ac_b_ex.fe_logical = ex.fe_logical;
5215
5216	BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
5217	BUG_ON(extent_logical_end(sbi, &ex) > orig_goal_end);
5218	}
5219
5220	pa->pa_lstart = ac->ac_b_ex.fe_logical;
5221	pa->pa_pstart = ext4_grp_offs_to_block(sb, fex: &ac->ac_b_ex);
5222	pa->pa_len = ac->ac_b_ex.fe_len;
5223	pa->pa_free = pa->pa_len;
5224	spin_lock_init(&pa->pa_lock);
5225	INIT_LIST_HEAD(list: &pa->pa_group_list);
5226	pa->pa_deleted = 0;
5227	pa->pa_type = MB_INODE_PA;
5228
5229	mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
5230	pa->pa_len, pa->pa_lstart);
5231	trace_ext4_mb_new_inode_pa(ac, pa);
5232
5233	atomic_add(i: pa->pa_free, v: &sbi->s_mb_preallocated);
5234	ext4_mb_use_inode_pa(ac, pa);
5235
5236	ei = EXT4_I(ac->ac_inode);
5237	grp = ext4_get_group_info(sb, group: ac->ac_b_ex.fe_group);
5238	if (!grp)
5239	return;
5240
5241	pa->pa_node_lock.inode_lock = &ei->i_prealloc_lock;
5242	pa->pa_inode = ac->ac_inode;
5243
5244	list_add(new: &pa->pa_group_list, head: &grp->bb_prealloc_list);
5245
5246	write_lock(pa->pa_node_lock.inode_lock);
5247	ext4_mb_pa_rb_insert(root: &ei->i_prealloc_node, new: &pa->pa_node.inode_node);
5248	write_unlock(pa->pa_node_lock.inode_lock);
5249	atomic_inc(v: &ei->i_prealloc_active);
5250	}
5251
5252	/*
5253	* creates new preallocated space for locality group inodes belongs to
5254	*/
5255	static noinline_for_stack void
5256	ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
5257	{
5258	struct super_block *sb = ac->ac_sb;
5259	struct ext4_locality_group *lg;
5260	struct ext4_prealloc_space *pa;
5261	struct ext4_group_info *grp;
5262
5263	/* preallocate only when found space is larger then requested */
5264	BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
5265	BUG_ON(ac->ac_status != AC_STATUS_FOUND);
5266	BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
5267	BUG_ON(ac->ac_pa == NULL);
5268
5269	pa = ac->ac_pa;
5270
5271	pa->pa_pstart = ext4_grp_offs_to_block(sb, fex: &ac->ac_b_ex);
5272	pa->pa_lstart = pa->pa_pstart;
5273	pa->pa_len = ac->ac_b_ex.fe_len;
5274	pa->pa_free = pa->pa_len;
5275	spin_lock_init(&pa->pa_lock);
5276	INIT_LIST_HEAD(list: &pa->pa_node.lg_list);
5277	INIT_LIST_HEAD(list: &pa->pa_group_list);
5278	pa->pa_deleted = 0;
5279	pa->pa_type = MB_GROUP_PA;
5280
5281	mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,
5282	pa->pa_len, pa->pa_lstart);
5283	trace_ext4_mb_new_group_pa(ac, pa);
5284
5285	ext4_mb_use_group_pa(ac, pa);
5286	atomic_add(i: pa->pa_free, v: &EXT4_SB(sb)->s_mb_preallocated);
5287
5288	grp = ext4_get_group_info(sb, group: ac->ac_b_ex.fe_group);
5289	if (!grp)
5290	return;
5291	lg = ac->ac_lg;
5292	BUG_ON(lg == NULL);
5293
5294	pa->pa_node_lock.lg_lock = &lg->lg_prealloc_lock;
5295	pa->pa_inode = NULL;
5296
5297	list_add(new: &pa->pa_group_list, head: &grp->bb_prealloc_list);
5298
5299	/*
5300	* We will later add the new pa to the right bucket
5301	* after updating the pa_free in ext4_mb_release_context
5302	*/
5303	}
5304
5305	static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
5306	{
5307	if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
5308	ext4_mb_new_group_pa(ac);
5309	else
5310	ext4_mb_new_inode_pa(ac);
5311	}
5312
5313	/*
5314	* finds all unused blocks in on-disk bitmap, frees them in
5315	* in-core bitmap and buddy.
5316	* @pa must be unlinked from inode and group lists, so that
5317	* nobody else can find/use it.
5318	* the caller MUST hold group/inode locks.
5319	* TODO: optimize the case when there are no in-core structures yet
5320	*/
5321	static noinline_for_stack void
5322	ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
5323	struct ext4_prealloc_space *pa)
5324	{
5325	struct super_block *sb = e4b->bd_sb;
5326	struct ext4_sb_info *sbi = EXT4_SB(sb);
5327	unsigned int end;
5328	unsigned int next;
5329	ext4_group_t group;
5330	ext4_grpblk_t bit;
5331	unsigned long long grp_blk_start;
5332	int free = 0;
5333
5334	BUG_ON(pa->pa_deleted == 0);
5335	ext4_get_group_no_and_offset(sb, blocknr: pa->pa_pstart, blockgrpp: &group, offsetp: &bit);
5336	grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);
5337	BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
5338	end = bit + pa->pa_len;
5339
5340	while (bit < end) {
5341	bit = mb_find_next_zero_bit(addr: bitmap_bh->b_data, max: end, start: bit);
5342	if (bit >= end)
5343	break;
5344	next = mb_find_next_bit(addr: bitmap_bh->b_data, max: end, start: bit);
5345	mb_debug(sb, "free preallocated %u/%u in group %u\n",
5346	(unsigned) ext4_group_first_block_no(sb, group) + bit,
5347	(unsigned) next - bit, (unsigned) group);
5348	free += next - bit;
5349
5350	trace_ext4_mballoc_discard(sb, NULL, group, start: bit, len: next - bit);
5351	trace_ext4_mb_release_inode_pa(pa, block: (grp_blk_start +
5352	EXT4_C2B(sbi, bit)),
5353	count: next - bit);
5354	mb_free_blocks(inode: pa->pa_inode, e4b, first: bit, count: next - bit);
5355	bit = next + 1;
5356	}
5357	if (free != pa->pa_free) {
5358	ext4_msg(e4b->bd_sb, KERN_CRIT,
5359	"pa %p: logic %lu, phys. %lu, len %d",
5360	pa, (unsigned long) pa->pa_lstart,
5361	(unsigned long) pa->pa_pstart,
5362	pa->pa_len);
5363	ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u",
5364	free, pa->pa_free);
5365	/*
5366	* pa is already deleted so we use the value obtained
5367	* from the bitmap and continue.
5368	*/
5369	}
5370	atomic_add(i: free, v: &sbi->s_mb_discarded);
5371	}
5372
5373	static noinline_for_stack void
5374	ext4_mb_release_group_pa(struct ext4_buddy *e4b,
5375	struct ext4_prealloc_space *pa)
5376	{
5377	struct super_block *sb = e4b->bd_sb;
5378	ext4_group_t group;
5379	ext4_grpblk_t bit;
5380
5381	trace_ext4_mb_release_group_pa(sb, pa);
5382	BUG_ON(pa->pa_deleted == 0);
5383	ext4_get_group_no_and_offset(sb, blocknr: pa->pa_pstart, blockgrpp: &group, offsetp: &bit);
5384	if (unlikely(group != e4b->bd_group && pa->pa_len != 0)) {
5385	ext4_warning(sb, "bad group: expected %u, group %u, pa_start %llu",
5386	e4b->bd_group, group, pa->pa_pstart);
5387	return;
5388	}
5389	mb_free_blocks(inode: pa->pa_inode, e4b, first: bit, count: pa->pa_len);
5390	atomic_add(i: pa->pa_len, v: &EXT4_SB(sb)->s_mb_discarded);
5391	trace_ext4_mballoc_discard(sb, NULL, group, start: bit, len: pa->pa_len);
5392	}
5393
5394	/*
5395	* releases all preallocations in given group
5396	*
5397	* first, we need to decide discard policy:
5398	* - when do we discard
5399	* 1) ENOSPC
5400	* - how many do we discard
5401	* 1) how many requested
5402	*/
5403	static noinline_for_stack int
5404	ext4_mb_discard_group_preallocations(struct super_block *sb,
5405	ext4_group_t group, int *busy)
5406	{
5407	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
5408	struct buffer_head *bitmap_bh = NULL;
5409	struct ext4_prealloc_space *pa, *tmp;
5410	LIST_HEAD(list);
5411	struct ext4_buddy e4b;
5412	struct ext4_inode_info *ei;
5413	int err;
5414	int free = 0;
5415
5416	if (!grp)
5417	return 0;
5418	mb_debug(sb, "discard preallocation for group %u\n", group);
5419	if (list_empty(head: &grp->bb_prealloc_list))
5420	goto out_dbg;
5421
5422	bitmap_bh = ext4_read_block_bitmap(sb, block_group: group);
5423	if (IS_ERR(ptr: bitmap_bh)) {
5424	err = PTR_ERR(ptr: bitmap_bh);
5425	ext4_error_err(sb, -err,
5426	"Error %d reading block bitmap for %u",
5427	err, group);
5428	goto out_dbg;
5429	}
5430
5431	err = ext4_mb_load_buddy(sb, group, e4b: &e4b);
5432	if (err) {
5433	ext4_warning(sb, "Error %d loading buddy information for %u",
5434	err, group);
5435	put_bh(bh: bitmap_bh);
5436	goto out_dbg;
5437	}
5438
5439	ext4_lock_group(sb, group);
5440	list_for_each_entry_safe(pa, tmp,
5441	&grp->bb_prealloc_list, pa_group_list) {
5442	spin_lock(lock: &pa->pa_lock);
5443	if (atomic_read(v: &pa->pa_count)) {
5444	spin_unlock(lock: &pa->pa_lock);
5445	*busy = 1;
5446	continue;
5447	}
5448	if (pa->pa_deleted) {
5449	spin_unlock(lock: &pa->pa_lock);
5450	continue;
5451	}
5452
5453	/* seems this one can be freed ... */
5454	ext4_mb_mark_pa_deleted(sb, pa);
5455
5456	if (!free)
5457	this_cpu_inc(discard_pa_seq);
5458
5459	/* we can trust pa_free ... */
5460	free += pa->pa_free;
5461
5462	spin_unlock(lock: &pa->pa_lock);
5463
5464	list_del(entry: &pa->pa_group_list);
5465	list_add(new: &pa->u.pa_tmp_list, head: &list);
5466	}
5467
5468	/* now free all selected PAs */
5469	list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
5470
5471	/* remove from object (inode or locality group) */
5472	if (pa->pa_type == MB_GROUP_PA) {
5473	spin_lock(lock: pa->pa_node_lock.lg_lock);
5474	list_del_rcu(entry: &pa->pa_node.lg_list);
5475	spin_unlock(lock: pa->pa_node_lock.lg_lock);
5476	} else {
5477	write_lock(pa->pa_node_lock.inode_lock);
5478	ei = EXT4_I(pa->pa_inode);
5479	rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
5480	write_unlock(pa->pa_node_lock.inode_lock);
5481	}
5482
5483	list_del(entry: &pa->u.pa_tmp_list);
5484
5485	if (pa->pa_type == MB_GROUP_PA) {
5486	ext4_mb_release_group_pa(e4b: &e4b, pa);
5487	call_rcu(head: &(pa)->u.pa_rcu, func: ext4_mb_pa_callback);
5488	} else {
5489	ext4_mb_release_inode_pa(e4b: &e4b, bitmap_bh, pa);
5490	ext4_mb_pa_free(pa);
5491	}
5492	}
5493
5494	ext4_unlock_group(sb, group);
5495	ext4_mb_unload_buddy(e4b: &e4b);
5496	put_bh(bh: bitmap_bh);
5497	out_dbg:
5498	mb_debug(sb, "discarded (%d) blocks preallocated for group %u bb_free (%d)\n",
5499	free, group, grp->bb_free);
5500	return free;
5501	}
5502
5503	/*
5504	* releases all non-used preallocated blocks for given inode
5505	*
5506	* It's important to discard preallocations under i_data_sem
5507	* We don't want another block to be served from the prealloc
5508	* space when we are discarding the inode prealloc space.
5509	*
5510	* FIXME!! Make sure it is valid at all the call sites
5511	*/
5512	void ext4_discard_preallocations(struct inode *inode)
5513	{
5514	struct ext4_inode_info *ei = EXT4_I(inode);
5515	struct super_block *sb = inode->i_sb;
5516	struct buffer_head *bitmap_bh = NULL;
5517	struct ext4_prealloc_space *pa, *tmp;
5518	ext4_group_t group = 0;
5519	LIST_HEAD(list);
5520	struct ext4_buddy e4b;
5521	struct rb_node *iter;
5522	int err;
5523
5524	if (!S_ISREG(inode->i_mode))
5525	return;
5526
5527	if (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY)
5528	return;
5529
5530	mb_debug(sb, "discard preallocation for inode %lu\n",
5531	inode->i_ino);
5532	trace_ext4_discard_preallocations(inode,
5533	len: atomic_read(v: &ei->i_prealloc_active));
5534
5535	repeat:
5536	/* first, collect all pa's in the inode */
5537	write_lock(&ei->i_prealloc_lock);
5538	for (iter = rb_first(&ei->i_prealloc_node); iter;
5539	iter = rb_next(iter)) {
5540	pa = rb_entry(iter, struct ext4_prealloc_space,
5541	pa_node.inode_node);
5542	BUG_ON(pa->pa_node_lock.inode_lock != &ei->i_prealloc_lock);
5543
5544	spin_lock(lock: &pa->pa_lock);
5545	if (atomic_read(v: &pa->pa_count)) {
5546	/* this shouldn't happen often - nobody should
5547	* use preallocation while we're discarding it */
5548	spin_unlock(lock: &pa->pa_lock);
5549	write_unlock(&ei->i_prealloc_lock);
5550	ext4_msg(sb, KERN_ERR,
5551	"uh-oh! used pa while discarding");
5552	WARN_ON(1);
5553	schedule_timeout_uninterruptible(HZ);
5554	goto repeat;
5555
5556	}
5557	if (pa->pa_deleted == 0) {
5558	ext4_mb_mark_pa_deleted(sb, pa);
5559	spin_unlock(lock: &pa->pa_lock);
5560	rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
5561	list_add(new: &pa->u.pa_tmp_list, head: &list);
5562	continue;
5563	}
5564
5565	/* someone is deleting pa right now */
5566	spin_unlock(lock: &pa->pa_lock);
5567	write_unlock(&ei->i_prealloc_lock);
5568
5569	/* we have to wait here because pa_deleted
5570	* doesn't mean pa is already unlinked from
5571	* the list. as we might be called from
5572	* ->clear_inode() the inode will get freed
5573	* and concurrent thread which is unlinking
5574	* pa from inode's list may access already
5575	* freed memory, bad-bad-bad */
5576
5577	/* XXX: if this happens too often, we can
5578	* add a flag to force wait only in case
5579	* of ->clear_inode(), but not in case of
5580	* regular truncate */
5581	schedule_timeout_uninterruptible(HZ);
5582	goto repeat;
5583	}
5584	write_unlock(&ei->i_prealloc_lock);
5585
5586	list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
5587	BUG_ON(pa->pa_type != MB_INODE_PA);
5588	group = ext4_get_group_number(sb, block: pa->pa_pstart);
5589
5590	err = ext4_mb_load_buddy_gfp(sb, group, e4b: &e4b,
5591	GFP_NOFS|__GFP_NOFAIL);
5592	if (err) {
5593	ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
5594	err, group);
5595	continue;
5596	}
5597
5598	bitmap_bh = ext4_read_block_bitmap(sb, block_group: group);
5599	if (IS_ERR(ptr: bitmap_bh)) {
5600	err = PTR_ERR(ptr: bitmap_bh);
5601	ext4_error_err(sb, -err, "Error %d reading block bitmap for %u",
5602	err, group);
5603	ext4_mb_unload_buddy(e4b: &e4b);
5604	continue;
5605	}
5606
5607	ext4_lock_group(sb, group);
5608	list_del(entry: &pa->pa_group_list);
5609	ext4_mb_release_inode_pa(e4b: &e4b, bitmap_bh, pa);
5610	ext4_unlock_group(sb, group);
5611
5612	ext4_mb_unload_buddy(e4b: &e4b);
5613	put_bh(bh: bitmap_bh);
5614
5615	list_del(entry: &pa->u.pa_tmp_list);
5616	ext4_mb_pa_free(pa);
5617	}
5618	}
5619
5620	static int ext4_mb_pa_alloc(struct ext4_allocation_context *ac)
5621	{
5622	struct ext4_prealloc_space *pa;
5623
5624	BUG_ON(ext4_pspace_cachep == NULL);
5625	pa = kmem_cache_zalloc(ext4_pspace_cachep, GFP_NOFS);
5626	if (!pa)
5627	return -ENOMEM;
5628	atomic_set(v: &pa->pa_count, i: 1);
5629	ac->ac_pa = pa;
5630	return 0;
5631	}
5632
5633	static void ext4_mb_pa_put_free(struct ext4_allocation_context *ac)
5634	{
5635	struct ext4_prealloc_space *pa = ac->ac_pa;
5636
5637	BUG_ON(!pa);
5638	ac->ac_pa = NULL;
5639	WARN_ON(!atomic_dec_and_test(&pa->pa_count));
5640	/*
5641	* current function is only called due to an error or due to
5642	* len of found blocks < len of requested blocks hence the PA has not
5643	* been added to grp->bb_prealloc_list. So we don't need to lock it
5644	*/
5645	pa->pa_deleted = 1;
5646	ext4_mb_pa_free(pa);
5647	}
5648
5649	#ifdef CONFIG_EXT4_DEBUG
5650	static inline void ext4_mb_show_pa(struct super_block *sb)
5651	{
5652	ext4_group_t i, ngroups;
5653
5654	if (ext4_emergency_state(sb))
5655	return;
5656
5657	ngroups = ext4_get_groups_count(sb);
5658	mb_debug(sb, "groups: ");
5659	for (i = 0; i < ngroups; i++) {
5660	struct ext4_group_info *grp = ext4_get_group_info(sb, group: i);
5661	struct ext4_prealloc_space *pa;
5662	ext4_grpblk_t start;
5663	struct list_head *cur;
5664
5665	if (!grp)
5666	continue;
5667	ext4_lock_group(sb, group: i);
5668	list_for_each(cur, &grp->bb_prealloc_list) {
5669	pa = list_entry(cur, struct ext4_prealloc_space,
5670	pa_group_list);
5671	spin_lock(lock: &pa->pa_lock);
5672	ext4_get_group_no_and_offset(sb, blocknr: pa->pa_pstart,
5673	NULL, offsetp: &start);
5674	spin_unlock(lock: &pa->pa_lock);
5675	mb_debug(sb, "PA:%u:%d:%d\n", i, start,
5676	pa->pa_len);
5677	}
5678	ext4_unlock_group(sb, group: i);
5679	mb_debug(sb, "%u: %d/%d\n", i, grp->bb_free,
5680	grp->bb_fragments);
5681	}
5682	}
5683
5684	static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
5685	{
5686	struct super_block *sb = ac->ac_sb;
5687
5688	if (ext4_emergency_state(sb))
5689	return;
5690
5691	mb_debug(sb, "Can't allocate:"
5692	" Allocation context details:");
5693	mb_debug(sb, "status %u flags 0x%x",
5694	ac->ac_status, ac->ac_flags);
5695	mb_debug(sb, "orig %lu/%lu/%lu@%lu, "
5696	"goal %lu/%lu/%lu@%lu, "
5697	"best %lu/%lu/%lu@%lu cr %d",
5698	(unsigned long)ac->ac_o_ex.fe_group,
5699	(unsigned long)ac->ac_o_ex.fe_start,
5700	(unsigned long)ac->ac_o_ex.fe_len,
5701	(unsigned long)ac->ac_o_ex.fe_logical,
5702	(unsigned long)ac->ac_g_ex.fe_group,
5703	(unsigned long)ac->ac_g_ex.fe_start,
5704	(unsigned long)ac->ac_g_ex.fe_len,
5705	(unsigned long)ac->ac_g_ex.fe_logical,
5706	(unsigned long)ac->ac_b_ex.fe_group,
5707	(unsigned long)ac->ac_b_ex.fe_start,
5708	(unsigned long)ac->ac_b_ex.fe_len,
5709	(unsigned long)ac->ac_b_ex.fe_logical,
5710	(int)ac->ac_criteria);
5711	mb_debug(sb, "%u found", ac->ac_found);
5712	mb_debug(sb, "used pa: %s, ", str_yes_no(ac->ac_pa));
5713	if (ac->ac_pa)
5714	mb_debug(sb, "pa_type %s\n", ac->ac_pa->pa_type == MB_GROUP_PA ?
5715	"group pa" : "inode pa");
5716	ext4_mb_show_pa(sb);
5717	}
5718	#else
5719	static inline void ext4_mb_show_pa(struct super_block *sb)
5720	{
5721	}
5722	static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
5723	{
5724	ext4_mb_show_pa(ac->ac_sb);
5725	}
5726	#endif
5727
5728	/*
5729	* We use locality group preallocation for small size file. The size of the
5730	* file is determined by the current size or the resulting size after
5731	* allocation which ever is larger
5732	*
5733	* One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req
5734	*/
5735	static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
5736	{
5737	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
5738	int bsbits = ac->ac_sb->s_blocksize_bits;
5739	loff_t size, isize;
5740	bool inode_pa_eligible, group_pa_eligible;
5741
5742	if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
5743	return;
5744
5745	if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
5746	return;
5747
5748	group_pa_eligible = sbi->s_mb_group_prealloc > 0;
5749	inode_pa_eligible = true;
5750	size = extent_logical_end(sbi, fex: &ac->ac_o_ex);
5751	isize = (i_size_read(inode: ac->ac_inode) + ac->ac_sb->s_blocksize - 1)
5752	>> bsbits;
5753
5754	/* No point in using inode preallocation for closed files */
5755	if ((size == isize) && !ext4_fs_is_busy(sbi) &&
5756	!inode_is_open_for_write(inode: ac->ac_inode))
5757	inode_pa_eligible = false;
5758
5759	size = max(size, isize);
5760	/* Don't use group allocation for large files */
5761	if (size > sbi->s_mb_stream_request)
5762	group_pa_eligible = false;
5763
5764	if (!group_pa_eligible) {
5765	if (inode_pa_eligible)
5766	ac->ac_flags |= EXT4_MB_STREAM_ALLOC;
5767	else
5768	ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC;
5769	return;
5770	}
5771
5772	BUG_ON(ac->ac_lg != NULL);
5773	/*
5774	* locality group prealloc space are per cpu. The reason for having
5775	* per cpu locality group is to reduce the contention between block
5776	* request from multiple CPUs.
5777	*/
5778	ac->ac_lg = raw_cpu_ptr(sbi->s_locality_groups);
5779
5780	/* we're going to use group allocation */
5781	ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
5782
5783	/* serialize all allocations in the group */
5784	mutex_lock(&ac->ac_lg->lg_mutex);
5785	}
5786
5787	static noinline_for_stack void
5788	ext4_mb_initialize_context(struct ext4_allocation_context *ac,
5789	struct ext4_allocation_request *ar)
5790	{
5791	struct super_block *sb = ar->inode->i_sb;
5792	struct ext4_sb_info *sbi = EXT4_SB(sb);
5793	struct ext4_super_block *es = sbi->s_es;
5794	ext4_group_t group;
5795	unsigned int len;
5796	ext4_fsblk_t goal;
5797	ext4_grpblk_t block;
5798
5799	/* we can't allocate > group size */
5800	len = ar->len;
5801
5802	/* just a dirty hack to filter too big requests */
5803	if (len >= EXT4_CLUSTERS_PER_GROUP(sb))
5804	len = EXT4_CLUSTERS_PER_GROUP(sb);
5805
5806	/* start searching from the goal */
5807	goal = ar->goal;
5808	if (goal < le32_to_cpu(es->s_first_data_block) ||
5809	goal >= ext4_blocks_count(es))
5810	goal = le32_to_cpu(es->s_first_data_block);
5811	ext4_get_group_no_and_offset(sb, blocknr: goal, blockgrpp: &group, offsetp: &block);
5812
5813	/* set up allocation goals */
5814	ac->ac_b_ex.fe_logical = EXT4_LBLK_CMASK(sbi, ar->logical);
5815	ac->ac_status = AC_STATUS_CONTINUE;
5816	ac->ac_sb = sb;
5817	ac->ac_inode = ar->inode;
5818	ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical;
5819	ac->ac_o_ex.fe_group = group;
5820	ac->ac_o_ex.fe_start = block;
5821	ac->ac_o_ex.fe_len = len;
5822	ac->ac_g_ex = ac->ac_o_ex;
5823	ac->ac_orig_goal_len = ac->ac_g_ex.fe_len;
5824	ac->ac_flags = ar->flags;
5825
5826	/* we have to define context: we'll work with a file or
5827	* locality group. this is a policy, actually */
5828	ext4_mb_group_or_file(ac);
5829
5830	mb_debug(sb, "init ac: %u blocks @ %u, goal %u, flags 0x%x, 2^%d, "
5831	"left: %u/%u, right %u/%u to %swritable\n",
5832	(unsigned) ar->len, (unsigned) ar->logical,
5833	(unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
5834	(unsigned) ar->lleft, (unsigned) ar->pleft,
5835	(unsigned) ar->lright, (unsigned) ar->pright,
5836	inode_is_open_for_write(ar->inode) ? "" : "non-");
5837	}
5838
5839	static noinline_for_stack void
5840	ext4_mb_discard_lg_preallocations(struct super_block *sb,
5841	struct ext4_locality_group *lg,
5842	int order, int total_entries)
5843	{
5844	ext4_group_t group = 0;
5845	struct ext4_buddy e4b;
5846	LIST_HEAD(discard_list);
5847	struct ext4_prealloc_space *pa, *tmp;
5848
5849	mb_debug(sb, "discard locality group preallocation\n");
5850
5851	spin_lock(lock: &lg->lg_prealloc_lock);
5852	list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
5853	pa_node.lg_list,
5854	lockdep_is_held(&lg->lg_prealloc_lock)) {
5855	spin_lock(lock: &pa->pa_lock);
5856	if (atomic_read(v: &pa->pa_count)) {
5857	/*
5858	* This is the pa that we just used
5859	* for block allocation. So don't
5860	* free that
5861	*/
5862	spin_unlock(lock: &pa->pa_lock);
5863	continue;
5864	}
5865	if (pa->pa_deleted) {
5866	spin_unlock(lock: &pa->pa_lock);
5867	continue;
5868	}
5869	/* only lg prealloc space */
5870	BUG_ON(pa->pa_type != MB_GROUP_PA);
5871
5872	/* seems this one can be freed ... */
5873	ext4_mb_mark_pa_deleted(sb, pa);
5874	spin_unlock(lock: &pa->pa_lock);
5875
5876	list_del_rcu(entry: &pa->pa_node.lg_list);
5877	list_add(new: &pa->u.pa_tmp_list, head: &discard_list);
5878
5879	total_entries--;
5880	if (total_entries <= 5) {
5881	/*
5882	* we want to keep only 5 entries
5883	* allowing it to grow to 8. This
5884	* mak sure we don't call discard
5885	* soon for this list.
5886	*/
5887	break;
5888	}
5889	}
5890	spin_unlock(lock: &lg->lg_prealloc_lock);
5891
5892	list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
5893	int err;
5894
5895	group = ext4_get_group_number(sb, block: pa->pa_pstart);
5896	err = ext4_mb_load_buddy_gfp(sb, group, e4b: &e4b,
5897	GFP_NOFS|__GFP_NOFAIL);
5898	if (err) {
5899	ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
5900	err, group);
5901	continue;
5902	}
5903	ext4_lock_group(sb, group);
5904	list_del(entry: &pa->pa_group_list);
5905	ext4_mb_release_group_pa(e4b: &e4b, pa);
5906	ext4_unlock_group(sb, group);
5907
5908	ext4_mb_unload_buddy(e4b: &e4b);
5909	list_del(entry: &pa->u.pa_tmp_list);
5910	call_rcu(head: &(pa)->u.pa_rcu, func: ext4_mb_pa_callback);
5911	}
5912	}
5913
5914	/*
5915	* We have incremented pa_count. So it cannot be freed at this
5916	* point. Also we hold lg_mutex. So no parallel allocation is
5917	* possible from this lg. That means pa_free cannot be updated.
5918	*
5919	* A parallel ext4_mb_discard_group_preallocations is possible.
5920	* which can cause the lg_prealloc_list to be updated.
5921	*/
5922
5923	static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
5924	{
5925	int order, added = 0, lg_prealloc_count = 1;
5926	struct super_block *sb = ac->ac_sb;
5927	struct ext4_locality_group *lg = ac->ac_lg;
5928	struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
5929
5930	order = fls(x: pa->pa_free) - 1;
5931	if (order > PREALLOC_TB_SIZE - 1)
5932	/* The max size of hash table is PREALLOC_TB_SIZE */
5933	order = PREALLOC_TB_SIZE - 1;
5934	/* Add the prealloc space to lg */
5935	spin_lock(lock: &lg->lg_prealloc_lock);
5936	list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
5937	pa_node.lg_list,
5938	lockdep_is_held(&lg->lg_prealloc_lock)) {
5939	spin_lock(lock: &tmp_pa->pa_lock);
5940	if (tmp_pa->pa_deleted) {
5941	spin_unlock(lock: &tmp_pa->pa_lock);
5942	continue;
5943	}
5944	if (!added && pa->pa_free < tmp_pa->pa_free) {
5945	/* Add to the tail of the previous entry */
5946	list_add_tail_rcu(new: &pa->pa_node.lg_list,
5947	head: &tmp_pa->pa_node.lg_list);
5948	added = 1;
5949	/*
5950	* we want to count the total
5951	* number of entries in the list
5952	*/
5953	}
5954	spin_unlock(lock: &tmp_pa->pa_lock);
5955	lg_prealloc_count++;
5956	}
5957	if (!added)
5958	list_add_tail_rcu(new: &pa->pa_node.lg_list,
5959	head: &lg->lg_prealloc_list[order]);
5960	spin_unlock(lock: &lg->lg_prealloc_lock);
5961
5962	/* Now trim the list to be not more than 8 elements */
5963	if (lg_prealloc_count > 8)
5964	ext4_mb_discard_lg_preallocations(sb, lg,
5965	order, total_entries: lg_prealloc_count);
5966	}
5967
5968	/*
5969	* release all resource we used in allocation
5970	*/
5971	static void ext4_mb_release_context(struct ext4_allocation_context *ac)
5972	{
5973	struct ext4_sb_info *sbi = EXT4_SB(sb: ac->ac_sb);
5974	struct ext4_prealloc_space *pa = ac->ac_pa;
5975	if (pa) {
5976	if (pa->pa_type == MB_GROUP_PA) {
5977	/* see comment in ext4_mb_use_group_pa() */
5978	spin_lock(lock: &pa->pa_lock);
5979	pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
5980	pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);
5981	pa->pa_free -= ac->ac_b_ex.fe_len;
5982	pa->pa_len -= ac->ac_b_ex.fe_len;
5983	spin_unlock(lock: &pa->pa_lock);
5984
5985	/*
5986	* We want to add the pa to the right bucket.
5987	* Remove it from the list and while adding
5988	* make sure the list to which we are adding
5989	* doesn't grow big.
5990	*/
5991	if (likely(pa->pa_free)) {
5992	spin_lock(lock: pa->pa_node_lock.lg_lock);
5993	list_del_rcu(entry: &pa->pa_node.lg_list);
5994	spin_unlock(lock: pa->pa_node_lock.lg_lock);
5995	ext4_mb_add_n_trim(ac);
5996	}
5997	}
5998
5999	ext4_mb_put_pa(ac, sb: ac->ac_sb, pa);
6000	}
6001	if (ac->ac_bitmap_folio)
6002	folio_put(folio: ac->ac_bitmap_folio);
6003	if (ac->ac_buddy_folio)
6004	folio_put(folio: ac->ac_buddy_folio);
6005	if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
6006	mutex_unlock(lock: &ac->ac_lg->lg_mutex);
6007	ext4_mb_collect_stats(ac);
6008	}
6009
6010	static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
6011	{
6012	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
6013	int ret;
6014	int freed = 0, busy = 0;
6015	int retry = 0;
6016
6017	trace_ext4_mb_discard_preallocations(sb, needed);
6018
6019	if (needed == 0)
6020	needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1;
6021	repeat:
6022	for (i = 0; i < ngroups && needed > 0; i++) {
6023	ret = ext4_mb_discard_group_preallocations(sb, group: i, busy: &busy);
6024	freed += ret;
6025	needed -= ret;
6026	cond_resched();
6027	}
6028
6029	if (needed > 0 && busy && ++retry < 3) {
6030	busy = 0;
6031	goto repeat;
6032	}
6033
6034	return freed;
6035	}
6036
6037	static bool ext4_mb_discard_preallocations_should_retry(struct super_block *sb,
6038	struct ext4_allocation_context *ac, u64 *seq)
6039	{
6040	int freed;
6041	u64 seq_retry = 0;
6042	bool ret = false;
6043
6044	freed = ext4_mb_discard_preallocations(sb, needed: ac->ac_o_ex.fe_len);
6045	if (freed) {
6046	ret = true;
6047	goto out_dbg;
6048	}
6049	seq_retry = ext4_get_discard_pa_seq_sum();
6050	if (!(ac->ac_flags & EXT4_MB_STRICT_CHECK) || seq_retry != *seq) {
6051	ac->ac_flags |= EXT4_MB_STRICT_CHECK;
6052	*seq = seq_retry;
6053	ret = true;
6054	}
6055
6056	out_dbg:
6057	mb_debug(sb, "freed %d, retry ? %s\n", freed, str_yes_no(ret));
6058	return ret;
6059	}
6060
6061	/*
6062	* Simple allocator for Ext4 fast commit replay path. It searches for blocks
6063	* linearly starting at the goal block and also excludes the blocks which
6064	* are going to be in use after fast commit replay.
6065	*/
6066	static ext4_fsblk_t
6067	ext4_mb_new_blocks_simple(struct ext4_allocation_request *ar, int *errp)
6068	{
6069	struct buffer_head *bitmap_bh;
6070	struct super_block *sb = ar->inode->i_sb;
6071	struct ext4_sb_info *sbi = EXT4_SB(sb);
6072	ext4_group_t group, nr;
6073	ext4_grpblk_t blkoff;
6074	ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
6075	ext4_grpblk_t i = 0;
6076	ext4_fsblk_t goal, block;
6077	struct ext4_super_block *es = sbi->s_es;
6078
6079	goal = ar->goal;
6080	if (goal < le32_to_cpu(es->s_first_data_block) ||
6081	goal >= ext4_blocks_count(es))
6082	goal = le32_to_cpu(es->s_first_data_block);
6083
6084	ar->len = 0;
6085	ext4_get_group_no_and_offset(sb, blocknr: goal, blockgrpp: &group, offsetp: &blkoff);
6086	for (nr = ext4_get_groups_count(sb); nr > 0; nr--) {
6087	bitmap_bh = ext4_read_block_bitmap(sb, block_group: group);
6088	if (IS_ERR(ptr: bitmap_bh)) {
6089	*errp = PTR_ERR(ptr: bitmap_bh);
6090	pr_warn("Failed to read block bitmap\n");
6091	return 0;
6092	}
6093
6094	while (1) {
6095	i = mb_find_next_zero_bit(addr: bitmap_bh->b_data, max,
6096	start: blkoff);
6097	if (i >= max)
6098	break;
6099	if (ext4_fc_replay_check_excluded(sb,
6100	block: ext4_group_first_block_no(sb, group_no: group) +
6101	EXT4_C2B(sbi, i))) {
6102	blkoff = i + 1;
6103	} else
6104	break;
6105	}
6106	brelse(bh: bitmap_bh);
6107	if (i < max)
6108	break;
6109
6110	if (++group >= ext4_get_groups_count(sb))
6111	group = 0;
6112
6113	blkoff = 0;
6114	}
6115
6116	if (i >= max) {
6117	*errp = -ENOSPC;
6118	return 0;
6119	}
6120
6121	block = ext4_group_first_block_no(sb, group_no: group) + EXT4_C2B(sbi, i);
6122	ext4_mb_mark_bb(sb, block, len: 1, state: true);
6123	ar->len = 1;
6124
6125	*errp = 0;
6126	return block;
6127	}
6128
6129	/*
6130	* Main entry point into mballoc to allocate blocks
6131	* it tries to use preallocation first, then falls back
6132	* to usual allocation
6133	*/
6134	ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
6135	struct ext4_allocation_request *ar, int *errp)
6136	{
6137	struct ext4_allocation_context *ac = NULL;
6138	struct ext4_sb_info *sbi;
6139	struct super_block *sb;
6140	ext4_fsblk_t block = 0;
6141	unsigned int inquota = 0;
6142	unsigned int reserv_clstrs = 0;
6143	int retries = 0;
6144	u64 seq;
6145
6146	might_sleep();
6147	sb = ar->inode->i_sb;
6148	sbi = EXT4_SB(sb);
6149
6150	trace_ext4_request_blocks(ar);
6151	if (sbi->s_mount_state & EXT4_FC_REPLAY)
6152	return ext4_mb_new_blocks_simple(ar, errp);
6153
6154	/* Allow to use superuser reservation for quota file */
6155	if (ext4_is_quota_file(inode: ar->inode))
6156	ar->flags |= EXT4_MB_USE_ROOT_BLOCKS;
6157
6158	if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
6159	/* Without delayed allocation we need to verify
6160	* there is enough free blocks to do block allocation
6161	* and verify allocation doesn't exceed the quota limits.
6162	*/
6163	while (ar->len &&
6164	ext4_claim_free_clusters(sbi, nclusters: ar->len, flags: ar->flags)) {
6165
6166	/* let others to free the space */
6167	cond_resched();
6168	ar->len = ar->len >> 1;
6169	}
6170	if (!ar->len) {
6171	ext4_mb_show_pa(sb);
6172	*errp = -ENOSPC;
6173	return 0;
6174	}
6175	reserv_clstrs = ar->len;
6176	if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) {
6177	dquot_alloc_block_nofail(inode: ar->inode,
6178	EXT4_C2B(sbi, ar->len));
6179	} else {
6180	while (ar->len &&
6181	dquot_alloc_block(inode: ar->inode,
6182	EXT4_C2B(sbi, ar->len))) {
6183
6184	ar->flags |= EXT4_MB_HINT_NOPREALLOC;
6185	ar->len--;
6186	}
6187	}
6188	inquota = ar->len;
6189	if (ar->len == 0) {
6190	*errp = -EDQUOT;
6191	goto out;
6192	}
6193	}
6194
6195	ac = kmem_cache_zalloc(ext4_ac_cachep, GFP_NOFS);
6196	if (!ac) {
6197	ar->len = 0;
6198	*errp = -ENOMEM;
6199	goto out;
6200	}
6201
6202	ext4_mb_initialize_context(ac, ar);
6203
6204	ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
6205	seq = this_cpu_read(discard_pa_seq);
6206	if (!ext4_mb_use_preallocated(ac)) {
6207	ac->ac_op = EXT4_MB_HISTORY_ALLOC;
6208	ext4_mb_normalize_request(ac, ar);
6209
6210	*errp = ext4_mb_pa_alloc(ac);
6211	if (*errp)
6212	goto errout;
6213	repeat:
6214	/* allocate space in core */
6215	*errp = ext4_mb_regular_allocator(ac);
6216	/*
6217	* pa allocated above is added to grp->bb_prealloc_list only
6218	* when we were able to allocate some block i.e. when
6219	* ac->ac_status == AC_STATUS_FOUND.
6220	* And error from above mean ac->ac_status != AC_STATUS_FOUND
6221	* So we have to free this pa here itself.
6222	*/
6223	if (*errp) {
6224	ext4_mb_pa_put_free(ac);
6225	ext4_discard_allocated_blocks(ac);
6226	goto errout;
6227	}
6228	if (ac->ac_status == AC_STATUS_FOUND &&
6229	ac->ac_o_ex.fe_len >= ac->ac_f_ex.fe_len)
6230	ext4_mb_pa_put_free(ac);
6231	}
6232	if (likely(ac->ac_status == AC_STATUS_FOUND)) {
6233	*errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs);
6234	if (*errp) {
6235	ext4_discard_allocated_blocks(ac);
6236	goto errout;
6237	} else {
6238	block = ext4_grp_offs_to_block(sb, fex: &ac->ac_b_ex);
6239	ar->len = ac->ac_b_ex.fe_len;
6240	}
6241	} else {
6242	if (++retries < 3 &&
6243	ext4_mb_discard_preallocations_should_retry(sb, ac, seq: &seq))
6244	goto repeat;
6245	/*
6246	* If block allocation fails then the pa allocated above
6247	* needs to be freed here itself.
6248	*/
6249	ext4_mb_pa_put_free(ac);
6250	*errp = -ENOSPC;
6251	}
6252
6253	if (*errp) {
6254	errout:
6255	ac->ac_b_ex.fe_len = 0;
6256	ar->len = 0;
6257	ext4_mb_show_ac(ac);
6258	}
6259	ext4_mb_release_context(ac);
6260	kmem_cache_free(s: ext4_ac_cachep, objp: ac);
6261	out:
6262	if (inquota && ar->len < inquota)
6263	dquot_free_block(inode: ar->inode, EXT4_C2B(sbi, inquota - ar->len));
6264	if (!ar->len) {
6265	if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
6266	/* release all the reserved blocks if non delalloc */
6267	percpu_counter_sub(fbc: &sbi->s_dirtyclusters_counter,
6268	amount: reserv_clstrs);
6269	}
6270
6271	trace_ext4_allocate_blocks(ar, block: (unsigned long long)block);
6272
6273	return block;
6274	}
6275
6276	/*
6277	* We can merge two free data extents only if the physical blocks
6278	* are contiguous, AND the extents were freed by the same transaction,
6279	* AND the blocks are associated with the same group.
6280	*/
6281	static void ext4_try_merge_freed_extent(struct ext4_sb_info *sbi,
6282	struct ext4_free_data *entry,
6283	struct ext4_free_data *new_entry,
6284	struct rb_root *entry_rb_root)
6285	{
6286	if ((entry->efd_tid != new_entry->efd_tid) ||
6287	(entry->efd_group != new_entry->efd_group))
6288	return;
6289	if (entry->efd_start_cluster + entry->efd_count ==
6290	new_entry->efd_start_cluster) {
6291	new_entry->efd_start_cluster = entry->efd_start_cluster;
6292	new_entry->efd_count += entry->efd_count;
6293	} else if (new_entry->efd_start_cluster + new_entry->efd_count ==
6294	entry->efd_start_cluster) {
6295	new_entry->efd_count += entry->efd_count;
6296	} else
6297	return;
6298	spin_lock(lock: &sbi->s_md_lock);
6299	list_del(entry: &entry->efd_list);
6300	spin_unlock(lock: &sbi->s_md_lock);
6301	rb_erase(&entry->efd_node, entry_rb_root);
6302	kmem_cache_free(s: ext4_free_data_cachep, objp: entry);
6303	}
6304
6305	static noinline_for_stack void
6306	ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
6307	struct ext4_free_data *new_entry)
6308	{
6309	ext4_group_t group = e4b->bd_group;
6310	ext4_grpblk_t cluster;
6311	ext4_grpblk_t clusters = new_entry->efd_count;
6312	struct ext4_free_data *entry;
6313	struct ext4_group_info *db = e4b->bd_info;
6314	struct super_block *sb = e4b->bd_sb;
6315	struct ext4_sb_info *sbi = EXT4_SB(sb);
6316	struct rb_node **n = &db->bb_free_root.rb_node, *node;
6317	struct rb_node *parent = NULL, *new_node;
6318
6319	BUG_ON(!ext4_handle_valid(handle));
6320	BUG_ON(e4b->bd_bitmap_folio == NULL);
6321	BUG_ON(e4b->bd_buddy_folio == NULL);
6322
6323	new_node = &new_entry->efd_node;
6324	cluster = new_entry->efd_start_cluster;
6325
6326	if (!*n) {
6327	/* first free block exent. We need to
6328	protect buddy cache from being freed,
6329	* otherwise we'll refresh it from
6330	* on-disk bitmap and lose not-yet-available
6331	* blocks */
6332	folio_get(folio: e4b->bd_buddy_folio);
6333	folio_get(folio: e4b->bd_bitmap_folio);
6334	}
6335	while (*n) {
6336	parent = *n;
6337	entry = rb_entry(parent, struct ext4_free_data, efd_node);
6338	if (cluster < entry->efd_start_cluster)
6339	n = &(*n)->rb_left;
6340	else if (cluster >= (entry->efd_start_cluster + entry->efd_count))
6341	n = &(*n)->rb_right;
6342	else {
6343	ext4_grp_locked_error(sb, group, 0,
6344	ext4_group_first_block_no(sb, group) +
6345	EXT4_C2B(sbi, cluster),
6346	"Block already on to-be-freed list");
6347	kmem_cache_free(s: ext4_free_data_cachep, objp: new_entry);
6348	return;
6349	}
6350	}
6351
6352	rb_link_node(node: new_node, parent, rb_link: n);
6353	rb_insert_color(new_node, &db->bb_free_root);
6354
6355	/* Now try to see the extent can be merged to left and right */
6356	node = rb_prev(new_node);
6357	if (node) {
6358	entry = rb_entry(node, struct ext4_free_data, efd_node);
6359	ext4_try_merge_freed_extent(sbi, entry, new_entry,
6360	entry_rb_root: &(db->bb_free_root));
6361	}
6362
6363	node = rb_next(new_node);
6364	if (node) {
6365	entry = rb_entry(node, struct ext4_free_data, efd_node);
6366	ext4_try_merge_freed_extent(sbi, entry, new_entry,
6367	entry_rb_root: &(db->bb_free_root));
6368	}
6369
6370	spin_lock(lock: &sbi->s_md_lock);
6371	list_add_tail(new: &new_entry->efd_list, head: &sbi->s_freed_data_list[new_entry->efd_tid & 1]);
6372	sbi->s_mb_free_pending += clusters;
6373	spin_unlock(lock: &sbi->s_md_lock);
6374	}
6375
6376	static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
6377	unsigned long count)
6378	{
6379	struct super_block *sb = inode->i_sb;
6380	ext4_group_t group;
6381	ext4_grpblk_t blkoff;
6382
6383	ext4_get_group_no_and_offset(sb, blocknr: block, blockgrpp: &group, offsetp: &blkoff);
6384	ext4_mb_mark_context(NULL, sb, state: false, group, blkoff, len: count,
6385	EXT4_MB_BITMAP_MARKED_CHECK |
6386	EXT4_MB_SYNC_UPDATE,
6387	NULL);
6388	}
6389
6390	/**
6391	* ext4_mb_clear_bb() -- helper function for freeing blocks.
6392	* Used by ext4_free_blocks()
6393	* @handle: handle for this transaction
6394	* @inode: inode
6395	* @block: starting physical block to be freed
6396	* @count: number of blocks to be freed
6397	* @flags: flags used by ext4_free_blocks
6398	*/
6399	static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
6400	ext4_fsblk_t block, unsigned long count,
6401	int flags)
6402	{
6403	struct super_block *sb = inode->i_sb;
6404	struct ext4_group_info *grp;
6405	unsigned int overflow;
6406	ext4_grpblk_t bit;
6407	ext4_group_t block_group;
6408	struct ext4_sb_info *sbi;
6409	struct ext4_buddy e4b;
6410	unsigned int count_clusters;
6411	int err = 0;
6412	int mark_flags = 0;
6413	ext4_grpblk_t changed;
6414
6415	sbi = EXT4_SB(sb);
6416
6417	if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
6418	!ext4_inode_block_valid(inode, start_blk: block, count)) {
6419	ext4_error(sb, "Freeing blocks in system zone - "
6420	"Block = %llu, count = %lu", block, count);
6421	/* err = 0. ext4_std_error should be a no op */
6422	goto error_out;
6423	}
6424	flags |= EXT4_FREE_BLOCKS_VALIDATED;
6425
6426	do_more:
6427	overflow = 0;
6428	ext4_get_group_no_and_offset(sb, blocknr: block, blockgrpp: &block_group, offsetp: &bit);
6429
6430	grp = ext4_get_group_info(sb, group: block_group);
6431	if (unlikely(!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)))
6432	return;
6433
6434	/*
6435	* Check to see if we are freeing blocks across a group
6436	* boundary.
6437	*/
6438	if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) {
6439	overflow = EXT4_C2B(sbi, bit) + count -
6440	EXT4_BLOCKS_PER_GROUP(sb);
6441	count -= overflow;
6442	/* The range changed so it's no longer validated */
6443	flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6444	}
6445	count_clusters = EXT4_NUM_B2C(sbi, count);
6446	trace_ext4_mballoc_free(sb, inode, group: block_group, start: bit, len: count_clusters);
6447
6448	/* __GFP_NOFAIL: retry infinitely, ignore TIF_MEMDIE and memcg limit. */
6449	err = ext4_mb_load_buddy_gfp(sb, group: block_group, e4b: &e4b,
6450	GFP_NOFS|__GFP_NOFAIL);
6451	if (err)
6452	goto error_out;
6453
6454	if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
6455	!ext4_inode_block_valid(inode, start_blk: block, count)) {
6456	ext4_error(sb, "Freeing blocks in system zone - "
6457	"Block = %llu, count = %lu", block, count);
6458	/* err = 0. ext4_std_error should be a no op */
6459	goto error_clean;
6460	}
6461
6462	#ifdef AGGRESSIVE_CHECK
6463	mark_flags |= EXT4_MB_BITMAP_MARKED_CHECK;
6464	#endif
6465	err = ext4_mb_mark_context(handle, sb, state: false, group: block_group, blkoff: bit,
6466	len: count_clusters, flags: mark_flags, ret_changed: &changed);
6467
6468
6469	if (err && changed == 0)
6470	goto error_clean;
6471
6472	#ifdef AGGRESSIVE_CHECK
6473	BUG_ON(changed != count_clusters);
6474	#endif
6475
6476	/*
6477	* We need to make sure we don't reuse the freed block until after the
6478	* transaction is committed. We make an exception if the inode is to be
6479	* written in writeback mode since writeback mode has weak data
6480	* consistency guarantees.
6481	*/
6482	if (ext4_handle_valid(handle) &&
6483	((flags & EXT4_FREE_BLOCKS_METADATA) ||
6484	!ext4_should_writeback_data(inode))) {
6485	struct ext4_free_data *new_entry;
6486	/*
6487	* We use __GFP_NOFAIL because ext4_free_blocks() is not allowed
6488	* to fail.
6489	*/
6490	new_entry = kmem_cache_alloc(ext4_free_data_cachep,
6491	GFP_NOFS|__GFP_NOFAIL);
6492	new_entry->efd_start_cluster = bit;
6493	new_entry->efd_group = block_group;
6494	new_entry->efd_count = count_clusters;
6495	new_entry->efd_tid = handle->h_transaction->t_tid;
6496
6497	ext4_lock_group(sb, group: block_group);
6498	ext4_mb_free_metadata(handle, e4b: &e4b, new_entry);
6499	} else {
6500	if (test_opt(sb, DISCARD)) {
6501	err = ext4_issue_discard(sb, block_group, cluster: bit,
6502	count: count_clusters);
6503	/*
6504	* Ignore EOPNOTSUPP error. This is consistent with
6505	* what happens when using journal.
6506	*/
6507	if (err == -EOPNOTSUPP)
6508	err = 0;
6509	if (err)
6510	ext4_msg(sb, KERN_WARNING, "discard request in"
6511	" group:%u block:%d count:%lu failed"
6512	" with %d", block_group, bit, count,
6513	err);
6514	}
6515
6516	EXT4_MB_GRP_CLEAR_TRIMMED(e4b.bd_info);
6517
6518	ext4_lock_group(sb, group: block_group);
6519	mb_free_blocks(inode, e4b: &e4b, first: bit, count: count_clusters);
6520	}
6521
6522	ext4_unlock_group(sb, group: block_group);
6523
6524	/*
6525	* on a bigalloc file system, defer the s_freeclusters_counter
6526	* update to the caller (ext4_remove_space and friends) so they
6527	* can determine if a cluster freed here should be rereserved
6528	*/
6529	if (!(flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)) {
6530	if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
6531	dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
6532	percpu_counter_add(fbc: &sbi->s_freeclusters_counter,
6533	amount: count_clusters);
6534	}
6535
6536	if (overflow && !err) {
6537	block += count;
6538	count = overflow;
6539	ext4_mb_unload_buddy(e4b: &e4b);
6540	/* The range changed so it's no longer validated */
6541	flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6542	goto do_more;
6543	}
6544
6545	error_clean:
6546	ext4_mb_unload_buddy(e4b: &e4b);
6547	error_out:
6548	ext4_std_error(sb, err);
6549	}
6550
6551	/**
6552	* ext4_free_blocks() -- Free given blocks and update quota
6553	* @handle: handle for this transaction
6554	* @inode: inode
6555	* @bh: optional buffer of the block to be freed
6556	* @block: starting physical block to be freed
6557	* @count: number of blocks to be freed
6558	* @flags: flags used by ext4_free_blocks
6559	*/
6560	void ext4_free_blocks(handle_t *handle, struct inode *inode,
6561	struct buffer_head *bh, ext4_fsblk_t block,
6562	unsigned long count, int flags)
6563	{
6564	struct super_block *sb = inode->i_sb;
6565	unsigned int overflow;
6566	struct ext4_sb_info *sbi;
6567
6568	sbi = EXT4_SB(sb);
6569
6570	if (bh) {
6571	if (block)
6572	BUG_ON(block != bh->b_blocknr);
6573	else
6574	block = bh->b_blocknr;
6575	}
6576
6577	if (sbi->s_mount_state & EXT4_FC_REPLAY) {
6578	ext4_free_blocks_simple(inode, block, EXT4_NUM_B2C(sbi, count));
6579	return;
6580	}
6581
6582	might_sleep();
6583
6584	if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
6585	!ext4_inode_block_valid(inode, start_blk: block, count)) {
6586	ext4_error(sb, "Freeing blocks not in datazone - "
6587	"block = %llu, count = %lu", block, count);
6588	return;
6589	}
6590	flags |= EXT4_FREE_BLOCKS_VALIDATED;
6591
6592	ext4_debug("freeing block %llu\n", block);
6593	trace_ext4_free_blocks(inode, block, count, flags);
6594
6595	if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
6596	BUG_ON(count > 1);
6597
6598	ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
6599	inode, bh, block);
6600	}
6601
6602	/*
6603	* If the extent to be freed does not begin on a cluster
6604	* boundary, we need to deal with partial clusters at the
6605	* beginning and end of the extent. Normally we will free
6606	* blocks at the beginning or the end unless we are explicitly
6607	* requested to avoid doing so.
6608	*/
6609	overflow = EXT4_PBLK_COFF(sbi, block);
6610	if (overflow) {
6611	if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
6612	overflow = sbi->s_cluster_ratio - overflow;
6613	block += overflow;
6614	if (count > overflow)
6615	count -= overflow;
6616	else
6617	return;
6618	} else {
6619	block -= overflow;
6620	count += overflow;
6621	}
6622	/* The range changed so it's no longer validated */
6623	flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6624	}
6625	overflow = EXT4_LBLK_COFF(sbi, count);
6626	if (overflow) {
6627	if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
6628	if (count > overflow)
6629	count -= overflow;
6630	else
6631	return;
6632	} else
6633	count += sbi->s_cluster_ratio - overflow;
6634	/* The range changed so it's no longer validated */
6635	flags &= ~EXT4_FREE_BLOCKS_VALIDATED;
6636	}
6637
6638	if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
6639	int i;
6640	int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
6641
6642	for (i = 0; i < count; i++) {
6643	cond_resched();
6644	if (is_metadata)
6645	bh = sb_find_get_block_nonatomic(sb: inode->i_sb,
6646	block: block + i);
6647	ext4_forget(handle, is_metadata, inode, bh, block + i);
6648	}
6649	}
6650
6651	ext4_mb_clear_bb(handle, inode, block, count, flags);
6652	}
6653
6654	/**
6655	* ext4_group_add_blocks() -- Add given blocks to an existing group
6656	* @handle: handle to this transaction
6657	* @sb: super block
6658	* @block: start physical block to add to the block group
6659	* @count: number of blocks to free
6660	*
6661	* This marks the blocks as free in the bitmap and buddy.
6662	*/
6663	int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
6664	ext4_fsblk_t block, unsigned long count)
6665	{
6666	ext4_group_t block_group;
6667	ext4_grpblk_t bit;
6668	struct ext4_sb_info *sbi = EXT4_SB(sb);
6669	struct ext4_buddy e4b;
6670	int err = 0;
6671	ext4_fsblk_t first_cluster = EXT4_B2C(sbi, block);
6672	ext4_fsblk_t last_cluster = EXT4_B2C(sbi, block + count - 1);
6673	unsigned long cluster_count = last_cluster - first_cluster + 1;
6674	ext4_grpblk_t changed;
6675
6676	ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
6677
6678	if (cluster_count == 0)
6679	return 0;
6680
6681	ext4_get_group_no_and_offset(sb, blocknr: block, blockgrpp: &block_group, offsetp: &bit);
6682	/*
6683	* Check to see if we are freeing blocks across a group
6684	* boundary.
6685	*/
6686	if (bit + cluster_count > EXT4_CLUSTERS_PER_GROUP(sb)) {
6687	ext4_warning(sb, "too many blocks added to group %u",
6688	block_group);
6689	err = -EINVAL;
6690	goto error_out;
6691	}
6692
6693	err = ext4_mb_load_buddy(sb, group: block_group, e4b: &e4b);
6694	if (err)
6695	goto error_out;
6696
6697	if (!ext4_sb_block_valid(sb, NULL, start_blk: block, count)) {
6698	ext4_error(sb, "Adding blocks in system zones - "
6699	"Block = %llu, count = %lu",
6700	block, count);
6701	err = -EINVAL;
6702	goto error_clean;
6703	}
6704
6705	err = ext4_mb_mark_context(handle, sb, state: false, group: block_group, blkoff: bit,
6706	len: cluster_count, EXT4_MB_BITMAP_MARKED_CHECK,
6707	ret_changed: &changed);
6708	if (err && changed == 0)
6709	goto error_clean;
6710
6711	if (changed != cluster_count)
6712	ext4_error(sb, "bit already cleared in group %u", block_group);
6713
6714	ext4_lock_group(sb, group: block_group);
6715	mb_free_blocks(NULL, e4b: &e4b, first: bit, count: cluster_count);
6716	ext4_unlock_group(sb, group: block_group);
6717	percpu_counter_add(fbc: &sbi->s_freeclusters_counter,
6718	amount: changed);
6719
6720	error_clean:
6721	ext4_mb_unload_buddy(e4b: &e4b);
6722	error_out:
6723	ext4_std_error(sb, err);
6724	return err;
6725	}
6726
6727	/**
6728	* ext4_trim_extent -- function to TRIM one single free extent in the group
6729	* @sb: super block for the file system
6730	* @start: starting block of the free extent in the alloc. group
6731	* @count: number of blocks to TRIM
6732	* @e4b: ext4 buddy for the group
6733	*
6734	* Trim "count" blocks starting at "start" in the "group". To assure that no
6735	* one will allocate those blocks, mark it as used in buddy bitmap. This must
6736	* be called with under the group lock.
6737	*/
6738	static int ext4_trim_extent(struct super_block *sb,
6739	int start, int count, struct ext4_buddy *e4b)
6740	__releases(bitlock)
6741	__acquires(bitlock)
6742	{
6743	struct ext4_free_extent ex;
6744	ext4_group_t group = e4b->bd_group;
6745	int ret = 0;
6746
6747	trace_ext4_trim_extent(sb, group, start, len: count);
6748
6749	assert_spin_locked(ext4_group_lock_ptr(sb, group));
6750
6751	ex.fe_start = start;
6752	ex.fe_group = group;
6753	ex.fe_len = count;
6754
6755	/*
6756	* Mark blocks used, so no one can reuse them while
6757	* being trimmed.
6758	*/
6759	mb_mark_used(e4b, ex: &ex);
6760	ext4_unlock_group(sb, group);
6761	ret = ext4_issue_discard(sb, block_group: group, cluster: start, count);
6762	ext4_lock_group(sb, group);
6763	mb_free_blocks(NULL, e4b, first: start, count: ex.fe_len);
6764	return ret;
6765	}
6766
6767	static ext4_grpblk_t ext4_last_grp_cluster(struct super_block *sb,
6768	ext4_group_t grp)
6769	{
6770	unsigned long nr_clusters_in_group;
6771
6772	if (grp < (ext4_get_groups_count(sb) - 1))
6773	nr_clusters_in_group = EXT4_CLUSTERS_PER_GROUP(sb);
6774	else
6775	nr_clusters_in_group = (ext4_blocks_count(es: EXT4_SB(sb)->s_es) -
6776	ext4_group_first_block_no(sb, group_no: grp))
6777	>> EXT4_CLUSTER_BITS(sb);
6778
6779	return nr_clusters_in_group - 1;
6780	}
6781
6782	static bool ext4_trim_interrupted(void)
6783	{
6784	return fatal_signal_pending(current) || freezing(current);
6785	}
6786
6787	static int ext4_try_to_trim_range(struct super_block *sb,
6788	struct ext4_buddy *e4b, ext4_grpblk_t start,
6789	ext4_grpblk_t max, ext4_grpblk_t minblocks)
6790	__acquires(ext4_group_lock_ptr(sb, e4b->bd_group))
6791	__releases(ext4_group_lock_ptr(sb, e4b->bd_group))
6792	{
6793	ext4_grpblk_t next, count, free_count, last, origin_start;
6794	bool set_trimmed = false;
6795	void *bitmap;
6796
6797	if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
6798	return 0;
6799
6800	last = ext4_last_grp_cluster(sb, grp: e4b->bd_group);
6801	bitmap = e4b->bd_bitmap;
6802	if (start == 0 && max >= last)
6803	set_trimmed = true;
6804	origin_start = start;
6805	start = max(e4b->bd_info->bb_first_free, start);
6806	count = 0;
6807	free_count = 0;
6808
6809	while (start <= max) {
6810	start = mb_find_next_zero_bit(addr: bitmap, max: max + 1, start);
6811	if (start > max)
6812	break;
6813
6814	next = mb_find_next_bit(addr: bitmap, max: last + 1, start);
6815	if (origin_start == 0 && next >= last)
6816	set_trimmed = true;
6817
6818	if ((next - start) >= minblocks) {
6819	int ret = ext4_trim_extent(sb, start, count: next - start, e4b);
6820
6821	if (ret && ret != -EOPNOTSUPP)
6822	return count;
6823	count += next - start;
6824	}
6825	free_count += next - start;
6826	start = next + 1;
6827
6828	if (ext4_trim_interrupted())
6829	return count;
6830
6831	if (need_resched()) {
6832	ext4_unlock_group(sb, group: e4b->bd_group);
6833	cond_resched();
6834	ext4_lock_group(sb, group: e4b->bd_group);
6835	}
6836
6837	if ((e4b->bd_info->bb_free - free_count) < minblocks)
6838	break;
6839	}
6840
6841	if (set_trimmed)
6842	EXT4_MB_GRP_SET_TRIMMED(e4b->bd_info);
6843
6844	return count;
6845	}
6846
6847	/**
6848	* ext4_trim_all_free -- function to trim all free space in alloc. group
6849	* @sb: super block for file system
6850	* @group: group to be trimmed
6851	* @start: first group block to examine
6852	* @max: last group block to examine
6853	* @minblocks: minimum extent block count
6854	*
6855	* ext4_trim_all_free walks through group's block bitmap searching for free
6856	* extents. When the free extent is found, mark it as used in group buddy
6857	* bitmap. Then issue a TRIM command on this extent and free the extent in
6858	* the group buddy bitmap.
6859	*/
6860	static ext4_grpblk_t
6861	ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
6862	ext4_grpblk_t start, ext4_grpblk_t max,
6863	ext4_grpblk_t minblocks)
6864	{
6865	struct ext4_buddy e4b;
6866	int ret;
6867
6868	trace_ext4_trim_all_free(sb, group, start, len: max);
6869
6870	ret = ext4_mb_load_buddy(sb, group, e4b: &e4b);
6871	if (ret) {
6872	ext4_warning(sb, "Error %d loading buddy information for %u",
6873	ret, group);
6874	return ret;
6875	}
6876
6877	ext4_lock_group(sb, group);
6878
6879	if (!EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) ||
6880	minblocks < EXT4_SB(sb)->s_last_trim_minblks)
6881	ret = ext4_try_to_trim_range(sb, e4b: &e4b, start, max, minblocks);
6882	else
6883	ret = 0;
6884
6885	ext4_unlock_group(sb, group);
6886	ext4_mb_unload_buddy(e4b: &e4b);
6887
6888	ext4_debug("trimmed %d blocks in the group %d\n",
6889	ret, group);
6890
6891	return ret;
6892	}
6893
6894	/**
6895	* ext4_trim_fs() -- trim ioctl handle function
6896	* @sb: superblock for filesystem
6897	* @range: fstrim_range structure
6898	*
6899	* start: First Byte to trim
6900	* len: number of Bytes to trim from start
6901	* minlen: minimum extent length in Bytes
6902	* ext4_trim_fs goes through all allocation groups containing Bytes from
6903	* start to start+len. For each such a group ext4_trim_all_free function
6904	* is invoked to trim all free space.
6905	*/
6906	int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
6907	{
6908	unsigned int discard_granularity = bdev_discard_granularity(bdev: sb->s_bdev);
6909	struct ext4_group_info *grp;
6910	ext4_group_t group, first_group, last_group;
6911	ext4_grpblk_t cnt = 0, first_cluster, last_cluster;
6912	uint64_t start, end, minlen, trimmed = 0;
6913	ext4_fsblk_t first_data_blk =
6914	le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
6915	ext4_fsblk_t max_blks = ext4_blocks_count(es: EXT4_SB(sb)->s_es);
6916	int ret = 0;
6917
6918	start = range->start >> sb->s_blocksize_bits;
6919	end = start + (range->len >> sb->s_blocksize_bits) - 1;
6920	minlen = EXT4_NUM_B2C(EXT4_SB(sb),
6921	range->minlen >> sb->s_blocksize_bits);
6922
6923	if (minlen > EXT4_CLUSTERS_PER_GROUP(sb) ||
6924	start >= max_blks ||
6925	range->len < sb->s_blocksize)
6926	return -EINVAL;
6927	/* No point to try to trim less than discard granularity */
6928	if (range->minlen < discard_granularity) {
6929	minlen = EXT4_NUM_B2C(EXT4_SB(sb),
6930	discard_granularity >> sb->s_blocksize_bits);
6931	if (minlen > EXT4_CLUSTERS_PER_GROUP(sb))
6932	goto out;
6933	}
6934	if (end >= max_blks - 1)
6935	end = max_blks - 1;
6936	if (end <= first_data_blk)
6937	goto out;
6938	if (start < first_data_blk)
6939	start = first_data_blk;
6940
6941	/* Determine first and last group to examine based on start and end */
6942	ext4_get_group_no_and_offset(sb, blocknr: (ext4_fsblk_t) start,
6943	blockgrpp: &first_group, offsetp: &first_cluster);
6944	ext4_get_group_no_and_offset(sb, blocknr: (ext4_fsblk_t) end,
6945	blockgrpp: &last_group, offsetp: &last_cluster);
6946
6947	/* end now represents the last cluster to discard in this group */
6948	end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
6949
6950	for (group = first_group; group <= last_group; group++) {
6951	if (ext4_trim_interrupted())
6952	break;
6953	grp = ext4_get_group_info(sb, group);
6954	if (!grp)
6955	continue;
6956	/* We only do this if the grp has never been initialized */
6957	if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) {
6958	ret = ext4_mb_init_group(sb, group, GFP_NOFS);
6959	if (ret)
6960	break;
6961	}
6962
6963	/*
6964	* For all the groups except the last one, last cluster will
6965	* always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to
6966	* change it for the last group, note that last_cluster is
6967	* already computed earlier by ext4_get_group_no_and_offset()
6968	*/
6969	if (group == last_group)
6970	end = last_cluster;
6971	if (grp->bb_free >= minlen) {
6972	cnt = ext4_trim_all_free(sb, group, start: first_cluster,
6973	max: end, minblocks: minlen);
6974	if (cnt < 0) {
6975	ret = cnt;
6976	break;
6977	}
6978	trimmed += cnt;
6979	}
6980
6981	/*
6982	* For every group except the first one, we are sure
6983	* that the first cluster to discard will be cluster #0.
6984	*/
6985	first_cluster = 0;
6986	}
6987
6988	if (!ret)
6989	EXT4_SB(sb)->s_last_trim_minblks = minlen;
6990
6991	out:
6992	range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
6993	return ret;
6994	}
6995
6996	/* Iterate all the free extents in the group. */
6997	int
6998	ext4_mballoc_query_range(
6999	struct super_block *sb,
7000	ext4_group_t group,
7001	ext4_grpblk_t first,
7002	ext4_grpblk_t end,
7003	ext4_mballoc_query_range_fn meta_formatter,
7004	ext4_mballoc_query_range_fn formatter,
7005	void *priv)
7006	{
7007	void *bitmap;
7008	ext4_grpblk_t start, next;
7009	struct ext4_buddy e4b;
7010	int error;
7011
7012	error = ext4_mb_load_buddy(sb, group, e4b: &e4b);
7013	if (error)
7014	return error;
7015	bitmap = e4b.bd_bitmap;
7016
7017	ext4_lock_group(sb, group);
7018
7019	start = max(e4b.bd_info->bb_first_free, first);
7020	if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
7021	end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
7022	if (meta_formatter && start != first) {
7023	if (start > end)
7024	start = end;
7025	ext4_unlock_group(sb, group);
7026	error = meta_formatter(sb, group, first, start - first,
7027	priv);
7028	if (error)
7029	goto out_unload;
7030	ext4_lock_group(sb, group);
7031	}
7032	while (start <= end) {
7033	start = mb_find_next_zero_bit(addr: bitmap, max: end + 1, start);
7034	if (start > end)
7035	break;
7036	next = mb_find_next_bit(addr: bitmap, max: end + 1, start);
7037
7038	ext4_unlock_group(sb, group);
7039	error = formatter(sb, group, start, next - start, priv);
7040	if (error)
7041	goto out_unload;
7042	ext4_lock_group(sb, group);
7043
7044	start = next + 1;
7045	}
7046
7047	ext4_unlock_group(sb, group);
7048	out_unload:
7049	ext4_mb_unload_buddy(e4b: &e4b);
7050
7051	return error;
7052	}
7053
7054	#ifdef CONFIG_EXT4_KUNIT_TESTS
7055	#include "mballoc-test.c"
7056	#endif
7057