1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* linux/fs/ext4/inode.c
4	*
5	* Copyright (C) 1992, 1993, 1994, 1995
6	* Remy Card (card@masi.ibp.fr)
7	* Laboratoire MASI - Institut Blaise Pascal
8	* Universite Pierre et Marie Curie (Paris VI)
9	*
10	* from
11	*
12	* linux/fs/minix/inode.c
13	*
14	* Copyright (C) 1991, 1992 Linus Torvalds
15	*
16	* 64-bit file support on 64-bit platforms by Jakub Jelinek
17	* (jj@sunsite.ms.mff.cuni.cz)
18	*
19	* Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
20	*/
21
22	#include <linux/fs.h>
23	#include <linux/mount.h>
24	#include <linux/time.h>
25	#include <linux/highuid.h>
26	#include <linux/pagemap.h>
27	#include <linux/dax.h>
28	#include <linux/quotaops.h>
29	#include <linux/string.h>
30	#include <linux/buffer_head.h>
31	#include <linux/writeback.h>
32	#include <linux/pagevec.h>
33	#include <linux/mpage.h>
34	#include <linux/namei.h>
35	#include <linux/uio.h>
36	#include <linux/bio.h>
37	#include <linux/workqueue.h>
38	#include <linux/kernel.h>
39	#include <linux/printk.h>
40	#include <linux/slab.h>
41	#include <linux/bitops.h>
42	#include <linux/iomap.h>
43	#include <linux/iversion.h>
44
45	#include "ext4_jbd2.h"
46	#include "xattr.h"
47	#include "acl.h"
48	#include "truncate.h"
49
50	#include <trace/events/ext4.h>
51
52	static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
53	struct ext4_inode_info *ei)
54	{
55	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
56	__u32 csum;
57	__u16 dummy_csum = 0;
58	int offset = offsetof(struct ext4_inode, i_checksum_lo);
59	unsigned int csum_size = sizeof(dummy_csum);
60
61	csum = ext4_chksum(sbi, crc: ei->i_csum_seed, address: (__u8 *)raw, length: offset);
62	csum = ext4_chksum(sbi, crc: csum, address: (__u8 *)&dummy_csum, length: csum_size);
63	offset += csum_size;
64	csum = ext4_chksum(sbi, crc: csum, address: (__u8 *)raw + offset,
65	EXT4_GOOD_OLD_INODE_SIZE - offset);
66
67	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
68	offset = offsetof(struct ext4_inode, i_checksum_hi);
69	csum = ext4_chksum(sbi, crc: csum, address: (__u8 *)raw +
70	EXT4_GOOD_OLD_INODE_SIZE,
71	length: offset - EXT4_GOOD_OLD_INODE_SIZE);
72	if (EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
73	csum = ext4_chksum(sbi, crc: csum, address: (__u8 *)&dummy_csum,
74	length: csum_size);
75	offset += csum_size;
76	}
77	csum = ext4_chksum(sbi, crc: csum, address: (__u8 *)raw + offset,
78	EXT4_INODE_SIZE(inode->i_sb) - offset);
79	}
80
81	return csum;
82	}
83
84	static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
85	struct ext4_inode_info *ei)
86	{
87	__u32 provided, calculated;
88
89	if (EXT4_SB(sb: inode->i_sb)->s_es->s_creator_os !=
90	cpu_to_le32(EXT4_OS_LINUX) ||
91	!ext4_has_metadata_csum(sb: inode->i_sb))
92	return 1;
93
94	provided = le16_to_cpu(raw->i_checksum_lo);
95	calculated = ext4_inode_csum(inode, raw, ei);
96	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
97	EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
98	provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
99	else
100	calculated &= 0xFFFF;
101
102	return provided == calculated;
103	}
104
105	void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
106	struct ext4_inode_info *ei)
107	{
108	__u32 csum;
109
110	if (EXT4_SB(sb: inode->i_sb)->s_es->s_creator_os !=
111	cpu_to_le32(EXT4_OS_LINUX) ||
112	!ext4_has_metadata_csum(sb: inode->i_sb))
113	return;
114
115	csum = ext4_inode_csum(inode, raw, ei);
116	raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
117	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
118	EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
119	raw->i_checksum_hi = cpu_to_le16(csum >> 16);
120	}
121
122	static inline int ext4_begin_ordered_truncate(struct inode *inode,
123	loff_t new_size)
124	{
125	trace_ext4_begin_ordered_truncate(inode, new_size);
126	/*
127	* If jinode is zero, then we never opened the file for
128	* writing, so there's no need to call
129	* jbd2_journal_begin_ordered_truncate() since there's no
130	* outstanding writes we need to flush.
131	*/
132	if (!EXT4_I(inode)->jinode)
133	return 0;
134	return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
135	EXT4_I(inode)->jinode,
136	new_size);
137	}
138
139	static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
140	int pextents);
141
142	/*
143	* Test whether an inode is a fast symlink.
144	* A fast symlink has its symlink data stored in ext4_inode_info->i_data.
145	*/
146	int ext4_inode_is_fast_symlink(struct inode *inode)
147	{
148	if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
149	int ea_blocks = EXT4_I(inode)->i_file_acl ?
150	EXT4_CLUSTER_SIZE(inode->i_sb) >> 9 : 0;
151
152	if (ext4_has_inline_data(inode))
153	return 0;
154
155	return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
156	}
157	return S_ISLNK(inode->i_mode) && inode->i_size &&
158	(inode->i_size < EXT4_N_BLOCKS * 4);
159	}
160
161	/*
162	* Called at the last iput() if i_nlink is zero.
163	*/
164	void ext4_evict_inode(struct inode *inode)
165	{
166	handle_t *handle;
167	int err;
168	/*
169	* Credits for final inode cleanup and freeing:
170	* sb + inode (ext4_orphan_del()), block bitmap, group descriptor
171	* (xattr block freeing), bitmap, group descriptor (inode freeing)
172	*/
173	int extra_credits = 6;
174	struct ext4_xattr_inode_array *ea_inode_array = NULL;
175	bool freeze_protected = false;
176
177	trace_ext4_evict_inode(inode);
178
179	if (EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)
180	ext4_evict_ea_inode(inode);
181	if (inode->i_nlink) {
182	truncate_inode_pages_final(&inode->i_data);
183
184	goto no_delete;
185	}
186
187	if (is_bad_inode(inode))
188	goto no_delete;
189	dquot_initialize(inode);
190
191	if (ext4_should_order_data(inode))
192	ext4_begin_ordered_truncate(inode, new_size: 0);
193	truncate_inode_pages_final(&inode->i_data);
194
195	/*
196	* For inodes with journalled data, transaction commit could have
197	* dirtied the inode. And for inodes with dioread_nolock, unwritten
198	* extents converting worker could merge extents and also have dirtied
199	* the inode. Flush worker is ignoring it because of I_FREEING flag but
200	* we still need to remove the inode from the writeback lists.
201	*/
202	if (!list_empty_careful(head: &inode->i_io_list))
203	inode_io_list_del(inode);
204
205	/*
206	* Protect us against freezing - iput() caller didn't have to have any
207	* protection against it. When we are in a running transaction though,
208	* we are already protected against freezing and we cannot grab further
209	* protection due to lock ordering constraints.
210	*/
211	if (!ext4_journal_current_handle()) {
212	sb_start_intwrite(sb: inode->i_sb);
213	freeze_protected = true;
214	}
215
216	if (!IS_NOQUOTA(inode))
217	extra_credits += EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb);
218
219	/*
220	* Block bitmap, group descriptor, and inode are accounted in both
221	* ext4_blocks_for_truncate() and extra_credits. So subtract 3.
222	*/
223	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE,
224	ext4_blocks_for_truncate(inode) + extra_credits - 3);
225	if (IS_ERR(ptr: handle)) {
226	ext4_std_error(inode->i_sb, PTR_ERR(handle));
227	/*
228	* If we're going to skip the normal cleanup, we still need to
229	* make sure that the in-core orphan linked list is properly
230	* cleaned up.
231	*/
232	ext4_orphan_del(NULL, inode);
233	if (freeze_protected)
234	sb_end_intwrite(sb: inode->i_sb);
235	goto no_delete;
236	}
237
238	if (IS_SYNC(inode))
239	ext4_handle_sync(handle);
240
241	/*
242	* Set inode->i_size to 0 before calling ext4_truncate(). We need
243	* special handling of symlinks here because i_size is used to
244	* determine whether ext4_inode_info->i_data contains symlink data or
245	* block mappings. Setting i_size to 0 will remove its fast symlink
246	* status. Erase i_data so that it becomes a valid empty block map.
247	*/
248	if (ext4_inode_is_fast_symlink(inode))
249	memset(EXT4_I(inode)->i_data, 0, sizeof(EXT4_I(inode)->i_data));
250	inode->i_size = 0;
251	err = ext4_mark_inode_dirty(handle, inode);
252	if (err) {
253	ext4_warning(inode->i_sb,
254	"couldn't mark inode dirty (err %d)", err);
255	goto stop_handle;
256	}
257	if (inode->i_blocks) {
258	err = ext4_truncate(inode);
259	if (err) {
260	ext4_error_err(inode->i_sb, -err,
261	"couldn't truncate inode %lu (err %d)",
262	inode->i_ino, err);
263	goto stop_handle;
264	}
265	}
266
267	/* Remove xattr references. */
268	err = ext4_xattr_delete_inode(handle, inode, array: &ea_inode_array,
269	extra_credits);
270	if (err) {
271	ext4_warning(inode->i_sb, "xattr delete (err %d)", err);
272	stop_handle:
273	ext4_journal_stop(handle);
274	ext4_orphan_del(NULL, inode);
275	if (freeze_protected)
276	sb_end_intwrite(sb: inode->i_sb);
277	ext4_xattr_inode_array_free(array: ea_inode_array);
278	goto no_delete;
279	}
280
281	/*
282	* Kill off the orphan record which ext4_truncate created.
283	* AKPM: I think this can be inside the above `if'.
284	* Note that ext4_orphan_del() has to be able to cope with the
285	* deletion of a non-existent orphan - this is because we don't
286	* know if ext4_truncate() actually created an orphan record.
287	* (Well, we could do this if we need to, but heck - it works)
288	*/
289	ext4_orphan_del(handle, inode);
290	EXT4_I(inode)->i_dtime = (__u32)ktime_get_real_seconds();
291
292	/*
293	* One subtle ordering requirement: if anything has gone wrong
294	* (transaction abort, IO errors, whatever), then we can still
295	* do these next steps (the fs will already have been marked as
296	* having errors), but we can't free the inode if the mark_dirty
297	* fails.
298	*/
299	if (ext4_mark_inode_dirty(handle, inode))
300	/* If that failed, just do the required in-core inode clear. */
301	ext4_clear_inode(inode);
302	else
303	ext4_free_inode(handle, inode);
304	ext4_journal_stop(handle);
305	if (freeze_protected)
306	sb_end_intwrite(sb: inode->i_sb);
307	ext4_xattr_inode_array_free(array: ea_inode_array);
308	return;
309	no_delete:
310	/*
311	* Check out some where else accidentally dirty the evicting inode,
312	* which may probably cause inode use-after-free issues later.
313	*/
314	WARN_ON_ONCE(!list_empty_careful(&inode->i_io_list));
315
316	if (!list_empty(head: &EXT4_I(inode)->i_fc_list))
317	ext4_fc_mark_ineligible(sb: inode->i_sb, reason: EXT4_FC_REASON_NOMEM, NULL);
318	ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
319	}
320
321	#ifdef CONFIG_QUOTA
322	qsize_t *ext4_get_reserved_space(struct inode *inode)
323	{
324	return &EXT4_I(inode)->i_reserved_quota;
325	}
326	#endif
327
328	/*
329	* Called with i_data_sem down, which is important since we can call
330	* ext4_discard_preallocations() from here.
331	*/
332	void ext4_da_update_reserve_space(struct inode *inode,
333	int used, int quota_claim)
334	{
335	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
336	struct ext4_inode_info *ei = EXT4_I(inode);
337
338	spin_lock(lock: &ei->i_block_reservation_lock);
339	trace_ext4_da_update_reserve_space(inode, used_blocks: used, quota_claim);
340	if (unlikely(used > ei->i_reserved_data_blocks)) {
341	ext4_warning(inode->i_sb, "%s: ino %lu, used %d "
342	"with only %d reserved data blocks",
343	__func__, inode->i_ino, used,
344	ei->i_reserved_data_blocks);
345	WARN_ON(1);
346	used = ei->i_reserved_data_blocks;
347	}
348
349	/* Update per-inode reservations */
350	ei->i_reserved_data_blocks -= used;
351	percpu_counter_sub(fbc: &sbi->s_dirtyclusters_counter, amount: used);
352
353	spin_unlock(lock: &ei->i_block_reservation_lock);
354
355	/* Update quota subsystem for data blocks */
356	if (quota_claim)
357	dquot_claim_block(inode, EXT4_C2B(sbi, used));
358	else {
359	/*
360	* We did fallocate with an offset that is already delayed
361	* allocated. So on delayed allocated writeback we should
362	* not re-claim the quota for fallocated blocks.
363	*/
364	dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
365	}
366
367	/*
368	* If we have done all the pending block allocations and if
369	* there aren't any writers on the inode, we can discard the
370	* inode's preallocations.
371	*/
372	if ((ei->i_reserved_data_blocks == 0) &&
373	!inode_is_open_for_write(inode))
374	ext4_discard_preallocations(inode);
375	}
376
377	static int __check_block_validity(struct inode *inode, const char *func,
378	unsigned int line,
379	struct ext4_map_blocks *map)
380	{
381	if (ext4_has_feature_journal(sb: inode->i_sb) &&
382	(inode->i_ino ==
383	le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum)))
384	return 0;
385	if (!ext4_inode_block_valid(inode, start_blk: map->m_pblk, count: map->m_len)) {
386	ext4_error_inode(inode, func, line, map->m_pblk,
387	"lblock %lu mapped to illegal pblock %llu "
388	"(length %d)", (unsigned long) map->m_lblk,
389	map->m_pblk, map->m_len);
390	return -EFSCORRUPTED;
391	}
392	return 0;
393	}
394
395	int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk, ext4_fsblk_t pblk,
396	ext4_lblk_t len)
397	{
398	int ret;
399
400	if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
401	return fscrypt_zeroout_range(inode, lblk, pblk, len);
402
403	ret = sb_issue_zeroout(sb: inode->i_sb, block: pblk, nr_blocks: len, GFP_NOFS);
404	if (ret > 0)
405	ret = 0;
406
407	return ret;
408	}
409
410	#define check_block_validity(inode, map) \
411	__check_block_validity((inode), __func__, __LINE__, (map))
412
413	#ifdef ES_AGGRESSIVE_TEST
414	static void ext4_map_blocks_es_recheck(handle_t *handle,
415	struct inode *inode,
416	struct ext4_map_blocks *es_map,
417	struct ext4_map_blocks *map,
418	int flags)
419	{
420	int retval;
421
422	map->m_flags = 0;
423	/*
424	* There is a race window that the result is not the same.
425	* e.g. xfstests #223 when dioread_nolock enables. The reason
426	* is that we lookup a block mapping in extent status tree with
427	* out taking i_data_sem. So at the time the unwritten extent
428	* could be converted.
429	*/
430	down_read(&EXT4_I(inode)->i_data_sem);
431	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
432	retval = ext4_ext_map_blocks(handle, inode, map, 0);
433	} else {
434	retval = ext4_ind_map_blocks(handle, inode, map, 0);
435	}
436	up_read((&EXT4_I(inode)->i_data_sem));
437
438	/*
439	* We don't check m_len because extent will be collpased in status
440	* tree. So the m_len might not equal.
441	*/
442	if (es_map->m_lblk != map->m_lblk ||
443	es_map->m_flags != map->m_flags ||
444	es_map->m_pblk != map->m_pblk) {
445	printk("ES cache assertion failed for inode: %lu "
446	"es_cached ex [%d/%d/%llu/%x] != "
447	"found ex [%d/%d/%llu/%x] retval %d flags %x\n",
448	inode->i_ino, es_map->m_lblk, es_map->m_len,
449	es_map->m_pblk, es_map->m_flags, map->m_lblk,
450	map->m_len, map->m_pblk, map->m_flags,
451	retval, flags);
452	}
453	}
454	#endif /* ES_AGGRESSIVE_TEST */
455
456	/*
457	* The ext4_map_blocks() function tries to look up the requested blocks,
458	* and returns if the blocks are already mapped.
459	*
460	* Otherwise it takes the write lock of the i_data_sem and allocate blocks
461	* and store the allocated blocks in the result buffer head and mark it
462	* mapped.
463	*
464	* If file type is extents based, it will call ext4_ext_map_blocks(),
465	* Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
466	* based files
467	*
468	* On success, it returns the number of blocks being mapped or allocated.
469	* If flags doesn't contain EXT4_GET_BLOCKS_CREATE the blocks are
470	* pre-allocated and unwritten, the resulting @map is marked as unwritten.
471	* If the flags contain EXT4_GET_BLOCKS_CREATE, it will mark @map as mapped.
472	*
473	* It returns 0 if plain look up failed (blocks have not been allocated), in
474	* that case, @map is returned as unmapped but we still do fill map->m_len to
475	* indicate the length of a hole starting at map->m_lblk.
476	*
477	* It returns the error in case of allocation failure.
478	*/
479	int ext4_map_blocks(handle_t *handle, struct inode *inode,
480	struct ext4_map_blocks *map, int flags)
481	{
482	struct extent_status es;
483	int retval;
484	int ret = 0;
485	#ifdef ES_AGGRESSIVE_TEST
486	struct ext4_map_blocks orig_map;
487
488	memcpy(&orig_map, map, sizeof(*map));
489	#endif
490
491	map->m_flags = 0;
492	ext_debug(inode, "flag 0x%x, max_blocks %u, logical block %lu\n",
493	flags, map->m_len, (unsigned long) map->m_lblk);
494
495	/*
496	* ext4_map_blocks returns an int, and m_len is an unsigned int
497	*/
498	if (unlikely(map->m_len > INT_MAX))
499	map->m_len = INT_MAX;
500
501	/* We can handle the block number less than EXT_MAX_BLOCKS */
502	if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS))
503	return -EFSCORRUPTED;
504
505	/* Lookup extent status tree firstly */
506	if (!(EXT4_SB(sb: inode->i_sb)->s_mount_state & EXT4_FC_REPLAY) &&
507	ext4_es_lookup_extent(inode, lblk: map->m_lblk, NULL, es: &es)) {
508	if (ext4_es_is_written(es: &es) || ext4_es_is_unwritten(es: &es)) {
509	map->m_pblk = ext4_es_pblock(es: &es) +
510	map->m_lblk - es.es_lblk;
511	map->m_flags |= ext4_es_is_written(es: &es) ?
512	EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN;
513	retval = es.es_len - (map->m_lblk - es.es_lblk);
514	if (retval > map->m_len)
515	retval = map->m_len;
516	map->m_len = retval;
517	} else if (ext4_es_is_delayed(es: &es) || ext4_es_is_hole(es: &es)) {
518	map->m_pblk = 0;
519	map->m_flags |= ext4_es_is_delayed(es: &es) ?
520	EXT4_MAP_DELAYED : 0;
521	retval = es.es_len - (map->m_lblk - es.es_lblk);
522	if (retval > map->m_len)
523	retval = map->m_len;
524	map->m_len = retval;
525	retval = 0;
526	} else {
527	BUG();
528	}
529
530	if (flags & EXT4_GET_BLOCKS_CACHED_NOWAIT)
531	return retval;
532	#ifdef ES_AGGRESSIVE_TEST
533	ext4_map_blocks_es_recheck(handle, inode, map,
534	&orig_map, flags);
535	#endif
536	goto found;
537	}
538	/*
539	* In the query cache no-wait mode, nothing we can do more if we
540	* cannot find extent in the cache.
541	*/
542	if (flags & EXT4_GET_BLOCKS_CACHED_NOWAIT)
543	return 0;
544
545	/*
546	* Try to see if we can get the block without requesting a new
547	* file system block.
548	*/
549	down_read(sem: &EXT4_I(inode)->i_data_sem);
550	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS)) {
551	retval = ext4_ext_map_blocks(handle, inode, map, flags: 0);
552	} else {
553	retval = ext4_ind_map_blocks(handle, inode, map, flags: 0);
554	}
555	if (retval > 0) {
556	unsigned int status;
557
558	if (unlikely(retval != map->m_len)) {
559	ext4_warning(inode->i_sb,
560	"ES len assertion failed for inode "
561	"%lu: retval %d != map->m_len %d",
562	inode->i_ino, retval, map->m_len);
563	WARN_ON(1);
564	}
565
566	status = map->m_flags & EXT4_MAP_UNWRITTEN ?
567	EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
568	if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
569	!(status & EXTENT_STATUS_WRITTEN) &&
570	ext4_es_scan_range(inode, matching_fn: &ext4_es_is_delayed, lblk: map->m_lblk,
571	end: map->m_lblk + map->m_len - 1))
572	status |= EXTENT_STATUS_DELAYED;
573	ext4_es_insert_extent(inode, lblk: map->m_lblk, len: map->m_len,
574	pblk: map->m_pblk, status);
575	}
576	up_read(sem: (&EXT4_I(inode)->i_data_sem));
577
578	found:
579	if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
580	ret = check_block_validity(inode, map);
581	if (ret != 0)
582	return ret;
583	}
584
585	/* If it is only a block(s) look up */
586	if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
587	return retval;
588
589	/*
590	* Returns if the blocks have already allocated
591	*
592	* Note that if blocks have been preallocated
593	* ext4_ext_map_blocks() returns with buffer head unmapped
594	*/
595	if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
596	/*
597	* If we need to convert extent to unwritten
598	* we continue and do the actual work in
599	* ext4_ext_map_blocks()
600	*/
601	if (!(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN))
602	return retval;
603
604	/*
605	* Here we clear m_flags because after allocating an new extent,
606	* it will be set again.
607	*/
608	map->m_flags &= ~EXT4_MAP_FLAGS;
609
610	/*
611	* New blocks allocate and/or writing to unwritten extent
612	* will possibly result in updating i_data, so we take
613	* the write lock of i_data_sem, and call get_block()
614	* with create == 1 flag.
615	*/
616	down_write(sem: &EXT4_I(inode)->i_data_sem);
617
618	/*
619	* We need to check for EXT4 here because migrate
620	* could have changed the inode type in between
621	*/
622	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS)) {
623	retval = ext4_ext_map_blocks(handle, inode, map, flags);
624	} else {
625	retval = ext4_ind_map_blocks(handle, inode, map, flags);
626
627	if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
628	/*
629	* We allocated new blocks which will result in
630	* i_data's format changing. Force the migrate
631	* to fail by clearing migrate flags
632	*/
633	ext4_clear_inode_state(inode, bit: EXT4_STATE_EXT_MIGRATE);
634	}
635	}
636
637	if (retval > 0) {
638	unsigned int status;
639
640	if (unlikely(retval != map->m_len)) {
641	ext4_warning(inode->i_sb,
642	"ES len assertion failed for inode "
643	"%lu: retval %d != map->m_len %d",
644	inode->i_ino, retval, map->m_len);
645	WARN_ON(1);
646	}
647
648	/*
649	* We have to zeroout blocks before inserting them into extent
650	* status tree. Otherwise someone could look them up there and
651	* use them before they are really zeroed. We also have to
652	* unmap metadata before zeroing as otherwise writeback can
653	* overwrite zeros with stale data from block device.
654	*/
655	if (flags & EXT4_GET_BLOCKS_ZERO &&
656	map->m_flags & EXT4_MAP_MAPPED &&
657	map->m_flags & EXT4_MAP_NEW) {
658	ret = ext4_issue_zeroout(inode, lblk: map->m_lblk,
659	pblk: map->m_pblk, len: map->m_len);
660	if (ret) {
661	retval = ret;
662	goto out_sem;
663	}
664	}
665
666	/*
667	* If the extent has been zeroed out, we don't need to update
668	* extent status tree.
669	*/
670	if ((flags & EXT4_GET_BLOCKS_PRE_IO) &&
671	ext4_es_lookup_extent(inode, lblk: map->m_lblk, NULL, es: &es)) {
672	if (ext4_es_is_written(es: &es))
673	goto out_sem;
674	}
675	status = map->m_flags & EXT4_MAP_UNWRITTEN ?
676	EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
677	if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
678	!(status & EXTENT_STATUS_WRITTEN) &&
679	ext4_es_scan_range(inode, matching_fn: &ext4_es_is_delayed, lblk: map->m_lblk,
680	end: map->m_lblk + map->m_len - 1))
681	status |= EXTENT_STATUS_DELAYED;
682	ext4_es_insert_extent(inode, lblk: map->m_lblk, len: map->m_len,
683	pblk: map->m_pblk, status);
684	}
685
686	out_sem:
687	up_write(sem: (&EXT4_I(inode)->i_data_sem));
688	if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
689	ret = check_block_validity(inode, map);
690	if (ret != 0)
691	return ret;
692
693	/*
694	* Inodes with freshly allocated blocks where contents will be
695	* visible after transaction commit must be on transaction's
696	* ordered data list.
697	*/
698	if (map->m_flags & EXT4_MAP_NEW &&
699	!(map->m_flags & EXT4_MAP_UNWRITTEN) &&
700	!(flags & EXT4_GET_BLOCKS_ZERO) &&
701	!ext4_is_quota_file(inode) &&
702	ext4_should_order_data(inode)) {
703	loff_t start_byte =
704	(loff_t)map->m_lblk << inode->i_blkbits;
705	loff_t length = (loff_t)map->m_len << inode->i_blkbits;
706
707	if (flags & EXT4_GET_BLOCKS_IO_SUBMIT)
708	ret = ext4_jbd2_inode_add_wait(handle, inode,
709	start_byte, length);
710	else
711	ret = ext4_jbd2_inode_add_write(handle, inode,
712	start_byte, length);
713	if (ret)
714	return ret;
715	}
716	}
717	if (retval > 0 && (map->m_flags & EXT4_MAP_UNWRITTEN ||
718	map->m_flags & EXT4_MAP_MAPPED))
719	ext4_fc_track_range(handle, inode, start: map->m_lblk,
720	end: map->m_lblk + map->m_len - 1);
721	if (retval < 0)
722	ext_debug(inode, "failed with err %d\n", retval);
723	return retval;
724	}
725
726	/*
727	* Update EXT4_MAP_FLAGS in bh->b_state. For buffer heads attached to pages
728	* we have to be careful as someone else may be manipulating b_state as well.
729	*/
730	static void ext4_update_bh_state(struct buffer_head *bh, unsigned long flags)
731	{
732	unsigned long old_state;
733	unsigned long new_state;
734
735	flags &= EXT4_MAP_FLAGS;
736
737	/* Dummy buffer_head? Set non-atomically. */
738	if (!bh->b_page) {
739	bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | flags;
740	return;
741	}
742	/*
743	* Someone else may be modifying b_state. Be careful! This is ugly but
744	* once we get rid of using bh as a container for mapping information
745	* to pass to / from get_block functions, this can go away.
746	*/
747	old_state = READ_ONCE(bh->b_state);
748	do {
749	new_state = (old_state & ~EXT4_MAP_FLAGS) | flags;
750	} while (unlikely(!try_cmpxchg(&bh->b_state, &old_state, new_state)));
751	}
752
753	static int _ext4_get_block(struct inode *inode, sector_t iblock,
754	struct buffer_head *bh, int flags)
755	{
756	struct ext4_map_blocks map;
757	int ret = 0;
758
759	if (ext4_has_inline_data(inode))
760	return -ERANGE;
761
762	map.m_lblk = iblock;
763	map.m_len = bh->b_size >> inode->i_blkbits;
764
765	ret = ext4_map_blocks(handle: ext4_journal_current_handle(), inode, map: &map,
766	flags);
767	if (ret > 0) {
768	map_bh(bh, sb: inode->i_sb, block: map.m_pblk);
769	ext4_update_bh_state(bh, flags: map.m_flags);
770	bh->b_size = inode->i_sb->s_blocksize * map.m_len;
771	ret = 0;
772	} else if (ret == 0) {
773	/* hole case, need to fill in bh->b_size */
774	bh->b_size = inode->i_sb->s_blocksize * map.m_len;
775	}
776	return ret;
777	}
778
779	int ext4_get_block(struct inode *inode, sector_t iblock,
780	struct buffer_head *bh, int create)
781	{
782	return _ext4_get_block(inode, iblock, bh,
783	flags: create ? EXT4_GET_BLOCKS_CREATE : 0);
784	}
785
786	/*
787	* Get block function used when preparing for buffered write if we require
788	* creating an unwritten extent if blocks haven't been allocated. The extent
789	* will be converted to written after the IO is complete.
790	*/
791	int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
792	struct buffer_head *bh_result, int create)
793	{
794	int ret = 0;
795
796	ext4_debug("ext4_get_block_unwritten: inode %lu, create flag %d\n",
797	inode->i_ino, create);
798	ret = _ext4_get_block(inode, iblock, bh: bh_result,
799	EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT);
800
801	/*
802	* If the buffer is marked unwritten, mark it as new to make sure it is
803	* zeroed out correctly in case of partial writes. Otherwise, there is
804	* a chance of stale data getting exposed.
805	*/
806	if (ret == 0 && buffer_unwritten(bh: bh_result))
807	set_buffer_new(bh_result);
808
809	return ret;
810	}
811
812	/* Maximum number of blocks we map for direct IO at once. */
813	#define DIO_MAX_BLOCKS 4096
814
815	/*
816	* `handle' can be NULL if create is zero
817	*/
818	struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
819	ext4_lblk_t block, int map_flags)
820	{
821	struct ext4_map_blocks map;
822	struct buffer_head *bh;
823	int create = map_flags & EXT4_GET_BLOCKS_CREATE;
824	bool nowait = map_flags & EXT4_GET_BLOCKS_CACHED_NOWAIT;
825	int err;
826
827	ASSERT((EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
828	|| handle != NULL || create == 0);
829	ASSERT(create == 0 || !nowait);
830
831	map.m_lblk = block;
832	map.m_len = 1;
833	err = ext4_map_blocks(handle, inode, map: &map, flags: map_flags);
834
835	if (err == 0)
836	return create ? ERR_PTR(error: -ENOSPC) : NULL;
837	if (err < 0)
838	return ERR_PTR(error: err);
839
840	if (nowait)
841	return sb_find_get_block(sb: inode->i_sb, block: map.m_pblk);
842
843	bh = sb_getblk(sb: inode->i_sb, block: map.m_pblk);
844	if (unlikely(!bh))
845	return ERR_PTR(error: -ENOMEM);
846	if (map.m_flags & EXT4_MAP_NEW) {
847	ASSERT(create != 0);
848	ASSERT((EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
849	|| (handle != NULL));
850
851	/*
852	* Now that we do not always journal data, we should
853	* keep in mind whether this should always journal the
854	* new buffer as metadata. For now, regular file
855	* writes use ext4_get_block instead, so it's not a
856	* problem.
857	*/
858	lock_buffer(bh);
859	BUFFER_TRACE(bh, "call get_create_access");
860	err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
861	EXT4_JTR_NONE);
862	if (unlikely(err)) {
863	unlock_buffer(bh);
864	goto errout;
865	}
866	if (!buffer_uptodate(bh)) {
867	memset(bh->b_data, 0, inode->i_sb->s_blocksize);
868	set_buffer_uptodate(bh);
869	}
870	unlock_buffer(bh);
871	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
872	err = ext4_handle_dirty_metadata(handle, inode, bh);
873	if (unlikely(err))
874	goto errout;
875	} else
876	BUFFER_TRACE(bh, "not a new buffer");
877	return bh;
878	errout:
879	brelse(bh);
880	return ERR_PTR(error: err);
881	}
882
883	struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
884	ext4_lblk_t block, int map_flags)
885	{
886	struct buffer_head *bh;
887	int ret;
888
889	bh = ext4_getblk(handle, inode, block, map_flags);
890	if (IS_ERR(ptr: bh))
891	return bh;
892	if (!bh || ext4_buffer_uptodate(bh))
893	return bh;
894
895	ret = ext4_read_bh_lock(bh, REQ_META | REQ_PRIO, wait: true);
896	if (ret) {
897	put_bh(bh);
898	return ERR_PTR(error: ret);
899	}
900	return bh;
901	}
902
903	/* Read a contiguous batch of blocks. */
904	int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
905	bool wait, struct buffer_head **bhs)
906	{
907	int i, err;
908
909	for (i = 0; i < bh_count; i++) {
910	bhs[i] = ext4_getblk(NULL, inode, block: block + i, map_flags: 0 /* map_flags */);
911	if (IS_ERR(ptr: bhs[i])) {
912	err = PTR_ERR(ptr: bhs[i]);
913	bh_count = i;
914	goto out_brelse;
915	}
916	}
917
918	for (i = 0; i < bh_count; i++)
919	/* Note that NULL bhs[i] is valid because of holes. */
920	if (bhs[i] && !ext4_buffer_uptodate(bh: bhs[i]))
921	ext4_read_bh_lock(bh: bhs[i], REQ_META | REQ_PRIO, wait: false);
922
923	if (!wait)
924	return 0;
925
926	for (i = 0; i < bh_count; i++)
927	if (bhs[i])
928	wait_on_buffer(bh: bhs[i]);
929
930	for (i = 0; i < bh_count; i++) {
931	if (bhs[i] && !buffer_uptodate(bh: bhs[i])) {
932	err = -EIO;
933	goto out_brelse;
934	}
935	}
936	return 0;
937
938	out_brelse:
939	for (i = 0; i < bh_count; i++) {
940	brelse(bh: bhs[i]);
941	bhs[i] = NULL;
942	}
943	return err;
944	}
945
946	int ext4_walk_page_buffers(handle_t *handle, struct inode *inode,
947	struct buffer_head *head,
948	unsigned from,
949	unsigned to,
950	int *partial,
951	int (*fn)(handle_t *handle, struct inode *inode,
952	struct buffer_head *bh))
953	{
954	struct buffer_head *bh;
955	unsigned block_start, block_end;
956	unsigned blocksize = head->b_size;
957	int err, ret = 0;
958	struct buffer_head *next;
959
960	for (bh = head, block_start = 0;
961	ret == 0 && (bh != head || !block_start);
962	block_start = block_end, bh = next) {
963	next = bh->b_this_page;
964	block_end = block_start + blocksize;
965	if (block_end <= from || block_start >= to) {
966	if (partial && !buffer_uptodate(bh))
967	*partial = 1;
968	continue;
969	}
970	err = (*fn)(handle, inode, bh);
971	if (!ret)
972	ret = err;
973	}
974	return ret;
975	}
976
977	/*
978	* Helper for handling dirtying of journalled data. We also mark the folio as
979	* dirty so that writeback code knows about this page (and inode) contains
980	* dirty data. ext4_writepages() then commits appropriate transaction to
981	* make data stable.
982	*/
983	static int ext4_dirty_journalled_data(handle_t *handle, struct buffer_head *bh)
984	{
985	folio_mark_dirty(folio: bh->b_folio);
986	return ext4_handle_dirty_metadata(handle, NULL, bh);
987	}
988
989	int do_journal_get_write_access(handle_t *handle, struct inode *inode,
990	struct buffer_head *bh)
991	{
992	int dirty = buffer_dirty(bh);
993	int ret;
994
995	if (!buffer_mapped(bh) || buffer_freed(bh))
996	return 0;
997	/*
998	* __block_write_begin() could have dirtied some buffers. Clean
999	* the dirty bit as jbd2_journal_get_write_access() could complain
1000	* otherwise about fs integrity issues. Setting of the dirty bit
1001	* by __block_write_begin() isn't a real problem here as we clear
1002	* the bit before releasing a page lock and thus writeback cannot
1003	* ever write the buffer.
1004	*/
1005	if (dirty)
1006	clear_buffer_dirty(bh);
1007	BUFFER_TRACE(bh, "get write access");
1008	ret = ext4_journal_get_write_access(handle, inode->i_sb, bh,
1009	EXT4_JTR_NONE);
1010	if (!ret && dirty)
1011	ret = ext4_dirty_journalled_data(handle, bh);
1012	return ret;
1013	}
1014
1015	#ifdef CONFIG_FS_ENCRYPTION
1016	static int ext4_block_write_begin(struct folio *folio, loff_t pos, unsigned len,
1017	get_block_t *get_block)
1018	{
1019	unsigned from = pos & (PAGE_SIZE - 1);
1020	unsigned to = from + len;
1021	struct inode *inode = folio->mapping->host;
1022	unsigned block_start, block_end;
1023	sector_t block;
1024	int err = 0;
1025	unsigned blocksize = inode->i_sb->s_blocksize;
1026	unsigned bbits;
1027	struct buffer_head *bh, *head, *wait[2];
1028	int nr_wait = 0;
1029	int i;
1030
1031	BUG_ON(!folio_test_locked(folio));
1032	BUG_ON(from > PAGE_SIZE);
1033	BUG_ON(to > PAGE_SIZE);
1034	BUG_ON(from > to);
1035
1036	head = folio_buffers(folio);
1037	if (!head)
1038	head = create_empty_buffers(folio, blocksize, b_state: 0);
1039	bbits = ilog2(blocksize);
1040	block = (sector_t)folio->index << (PAGE_SHIFT - bbits);
1041
1042	for (bh = head, block_start = 0; bh != head || !block_start;
1043	block++, block_start = block_end, bh = bh->b_this_page) {
1044	block_end = block_start + blocksize;
1045	if (block_end <= from || block_start >= to) {
1046	if (folio_test_uptodate(folio)) {
1047	set_buffer_uptodate(bh);
1048	}
1049	continue;
1050	}
1051	if (buffer_new(bh))
1052	clear_buffer_new(bh);
1053	if (!buffer_mapped(bh)) {
1054	WARN_ON(bh->b_size != blocksize);
1055	err = get_block(inode, block, bh, 1);
1056	if (err)
1057	break;
1058	if (buffer_new(bh)) {
1059	if (folio_test_uptodate(folio)) {
1060	clear_buffer_new(bh);
1061	set_buffer_uptodate(bh);
1062	mark_buffer_dirty(bh);
1063	continue;
1064	}
1065	if (block_end > to || block_start < from)
1066	folio_zero_segments(folio, start1: to,
1067	xend1: block_end,
1068	start2: block_start, xend2: from);
1069	continue;
1070	}
1071	}
1072	if (folio_test_uptodate(folio)) {
1073	set_buffer_uptodate(bh);
1074	continue;
1075	}
1076	if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
1077	!buffer_unwritten(bh) &&
1078	(block_start < from || block_end > to)) {
1079	ext4_read_bh_lock(bh, op_flags: 0, wait: false);
1080	wait[nr_wait++] = bh;
1081	}
1082	}
1083	/*
1084	* If we issued read requests, let them complete.
1085	*/
1086	for (i = 0; i < nr_wait; i++) {
1087	wait_on_buffer(bh: wait[i]);
1088	if (!buffer_uptodate(bh: wait[i]))
1089	err = -EIO;
1090	}
1091	if (unlikely(err)) {
1092	folio_zero_new_buffers(folio, from, to);
1093	} else if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
1094	for (i = 0; i < nr_wait; i++) {
1095	int err2;
1096
1097	err2 = fscrypt_decrypt_pagecache_blocks(folio,
1098	len: blocksize, offs: bh_offset(bh: wait[i]));
1099	if (err2) {
1100	clear_buffer_uptodate(bh: wait[i]);
1101	err = err2;
1102	}
1103	}
1104	}
1105
1106	return err;
1107	}
1108	#endif
1109
1110	/*
1111	* To preserve ordering, it is essential that the hole instantiation and
1112	* the data write be encapsulated in a single transaction. We cannot
1113	* close off a transaction and start a new one between the ext4_get_block()
1114	* and the ext4_write_end(). So doing the jbd2_journal_start at the start of
1115	* ext4_write_begin() is the right place.
1116	*/
1117	static int ext4_write_begin(struct file *file, struct address_space *mapping,
1118	loff_t pos, unsigned len,
1119	struct page **pagep, void **fsdata)
1120	{
1121	struct inode *inode = mapping->host;
1122	int ret, needed_blocks;
1123	handle_t *handle;
1124	int retries = 0;
1125	struct folio *folio;
1126	pgoff_t index;
1127	unsigned from, to;
1128
1129	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
1130	return -EIO;
1131
1132	trace_ext4_write_begin(inode, pos, len);
1133	/*
1134	* Reserve one block more for addition to orphan list in case
1135	* we allocate blocks but write fails for some reason
1136	*/
1137	needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
1138	index = pos >> PAGE_SHIFT;
1139	from = pos & (PAGE_SIZE - 1);
1140	to = from + len;
1141
1142	if (ext4_test_inode_state(inode, bit: EXT4_STATE_MAY_INLINE_DATA)) {
1143	ret = ext4_try_to_write_inline_data(mapping, inode, pos, len,
1144	pagep);
1145	if (ret < 0)
1146	return ret;
1147	if (ret == 1)
1148	return 0;
1149	}
1150
1151	/*
1152	* __filemap_get_folio() can take a long time if the
1153	* system is thrashing due to memory pressure, or if the folio
1154	* is being written back. So grab it first before we start
1155	* the transaction handle. This also allows us to allocate
1156	* the folio (if needed) without using GFP_NOFS.
1157	*/
1158	retry_grab:
1159	folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
1160	gfp: mapping_gfp_mask(mapping));
1161	if (IS_ERR(ptr: folio))
1162	return PTR_ERR(ptr: folio);
1163	/*
1164	* The same as page allocation, we prealloc buffer heads before
1165	* starting the handle.
1166	*/
1167	if (!folio_buffers(folio))
1168	create_empty_buffers(folio, blocksize: inode->i_sb->s_blocksize, b_state: 0);
1169
1170	folio_unlock(folio);
1171
1172	retry_journal:
1173	handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
1174	if (IS_ERR(ptr: handle)) {
1175	folio_put(folio);
1176	return PTR_ERR(ptr: handle);
1177	}
1178
1179	folio_lock(folio);
1180	if (folio->mapping != mapping) {
1181	/* The folio got truncated from under us */
1182	folio_unlock(folio);
1183	folio_put(folio);
1184	ext4_journal_stop(handle);
1185	goto retry_grab;
1186	}
1187	/* In case writeback began while the folio was unlocked */
1188	folio_wait_stable(folio);
1189
1190	#ifdef CONFIG_FS_ENCRYPTION
1191	if (ext4_should_dioread_nolock(inode))
1192	ret = ext4_block_write_begin(folio, pos, len,
1193	get_block: ext4_get_block_unwritten);
1194	else
1195	ret = ext4_block_write_begin(folio, pos, len, get_block: ext4_get_block);
1196	#else
1197	if (ext4_should_dioread_nolock(inode))
1198	ret = __block_write_begin(&folio->page, pos, len,
1199	ext4_get_block_unwritten);
1200	else
1201	ret = __block_write_begin(&folio->page, pos, len, ext4_get_block);
1202	#endif
1203	if (!ret && ext4_should_journal_data(inode)) {
1204	ret = ext4_walk_page_buffers(handle, inode,
1205	folio_buffers(folio), from, to,
1206	NULL, fn: do_journal_get_write_access);
1207	}
1208
1209	if (ret) {
1210	bool extended = (pos + len > inode->i_size) &&
1211	!ext4_verity_in_progress(inode);
1212
1213	folio_unlock(folio);
1214	/*
1215	* __block_write_begin may have instantiated a few blocks
1216	* outside i_size. Trim these off again. Don't need
1217	* i_size_read because we hold i_rwsem.
1218	*
1219	* Add inode to orphan list in case we crash before
1220	* truncate finishes
1221	*/
1222	if (extended && ext4_can_truncate(inode))
1223	ext4_orphan_add(handle, inode);
1224
1225	ext4_journal_stop(handle);
1226	if (extended) {
1227	ext4_truncate_failed_write(inode);
1228	/*
1229	* If truncate failed early the inode might
1230	* still be on the orphan list; we need to
1231	* make sure the inode is removed from the
1232	* orphan list in that case.
1233	*/
1234	if (inode->i_nlink)
1235	ext4_orphan_del(NULL, inode);
1236	}
1237
1238	if (ret == -ENOSPC &&
1239	ext4_should_retry_alloc(sb: inode->i_sb, retries: &retries))
1240	goto retry_journal;
1241	folio_put(folio);
1242	return ret;
1243	}
1244	*pagep = &folio->page;
1245	return ret;
1246	}
1247
1248	/* For write_end() in data=journal mode */
1249	static int write_end_fn(handle_t *handle, struct inode *inode,
1250	struct buffer_head *bh)
1251	{
1252	int ret;
1253	if (!buffer_mapped(bh) || buffer_freed(bh))
1254	return 0;
1255	set_buffer_uptodate(bh);
1256	ret = ext4_dirty_journalled_data(handle, bh);
1257	clear_buffer_meta(bh);
1258	clear_buffer_prio(bh);
1259	return ret;
1260	}
1261
1262	/*
1263	* We need to pick up the new inode size which generic_commit_write gave us
1264	* `file' can be NULL - eg, when called from page_symlink().
1265	*
1266	* ext4 never places buffers on inode->i_mapping->i_private_list. metadata
1267	* buffers are managed internally.
1268	*/
1269	static int ext4_write_end(struct file *file,
1270	struct address_space *mapping,
1271	loff_t pos, unsigned len, unsigned copied,
1272	struct page *page, void *fsdata)
1273	{
1274	struct folio *folio = page_folio(page);
1275	handle_t *handle = ext4_journal_current_handle();
1276	struct inode *inode = mapping->host;
1277	loff_t old_size = inode->i_size;
1278	int ret = 0, ret2;
1279	int i_size_changed = 0;
1280	bool verity = ext4_verity_in_progress(inode);
1281
1282	trace_ext4_write_end(inode, pos, len, copied);
1283
1284	if (ext4_has_inline_data(inode) &&
1285	ext4_test_inode_state(inode, bit: EXT4_STATE_MAY_INLINE_DATA))
1286	return ext4_write_inline_data_end(inode, pos, len, copied,
1287	folio);
1288
1289	copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1290	/*
1291	* it's important to update i_size while still holding folio lock:
1292	* page writeout could otherwise come in and zero beyond i_size.
1293	*
1294	* If FS_IOC_ENABLE_VERITY is running on this inode, then Merkle tree
1295	* blocks are being written past EOF, so skip the i_size update.
1296	*/
1297	if (!verity)
1298	i_size_changed = ext4_update_inode_size(inode, newsize: pos + copied);
1299	folio_unlock(folio);
1300	folio_put(folio);
1301
1302	if (old_size < pos && !verity)
1303	pagecache_isize_extended(inode, from: old_size, to: pos);
1304	/*
1305	* Don't mark the inode dirty under folio lock. First, it unnecessarily
1306	* makes the holding time of folio lock longer. Second, it forces lock
1307	* ordering of folio lock and transaction start for journaling
1308	* filesystems.
1309	*/
1310	if (i_size_changed)
1311	ret = ext4_mark_inode_dirty(handle, inode);
1312
1313	if (pos + len > inode->i_size && !verity && ext4_can_truncate(inode))
1314	/* if we have allocated more blocks and copied
1315	* less. We will have blocks allocated outside
1316	* inode->i_size. So truncate them
1317	*/
1318	ext4_orphan_add(handle, inode);
1319
1320	ret2 = ext4_journal_stop(handle);
1321	if (!ret)
1322	ret = ret2;
1323
1324	if (pos + len > inode->i_size && !verity) {
1325	ext4_truncate_failed_write(inode);
1326	/*
1327	* If truncate failed early the inode might still be
1328	* on the orphan list; we need to make sure the inode
1329	* is removed from the orphan list in that case.
1330	*/
1331	if (inode->i_nlink)
1332	ext4_orphan_del(NULL, inode);
1333	}
1334
1335	return ret ? ret : copied;
1336	}
1337
1338	/*
1339	* This is a private version of folio_zero_new_buffers() which doesn't
1340	* set the buffer to be dirty, since in data=journalled mode we need
1341	* to call ext4_dirty_journalled_data() instead.
1342	*/
1343	static void ext4_journalled_zero_new_buffers(handle_t *handle,
1344	struct inode *inode,
1345	struct folio *folio,
1346	unsigned from, unsigned to)
1347	{
1348	unsigned int block_start = 0, block_end;
1349	struct buffer_head *head, *bh;
1350
1351	bh = head = folio_buffers(folio);
1352	do {
1353	block_end = block_start + bh->b_size;
1354	if (buffer_new(bh)) {
1355	if (block_end > from && block_start < to) {
1356	if (!folio_test_uptodate(folio)) {
1357	unsigned start, size;
1358
1359	start = max(from, block_start);
1360	size = min(to, block_end) - start;
1361
1362	folio_zero_range(folio, start, length: size);
1363	write_end_fn(handle, inode, bh);
1364	}
1365	clear_buffer_new(bh);
1366	}
1367	}
1368	block_start = block_end;
1369	bh = bh->b_this_page;
1370	} while (bh != head);
1371	}
1372
1373	static int ext4_journalled_write_end(struct file *file,
1374	struct address_space *mapping,
1375	loff_t pos, unsigned len, unsigned copied,
1376	struct page *page, void *fsdata)
1377	{
1378	struct folio *folio = page_folio(page);
1379	handle_t *handle = ext4_journal_current_handle();
1380	struct inode *inode = mapping->host;
1381	loff_t old_size = inode->i_size;
1382	int ret = 0, ret2;
1383	int partial = 0;
1384	unsigned from, to;
1385	int size_changed = 0;
1386	bool verity = ext4_verity_in_progress(inode);
1387
1388	trace_ext4_journalled_write_end(inode, pos, len, copied);
1389	from = pos & (PAGE_SIZE - 1);
1390	to = from + len;
1391
1392	BUG_ON(!ext4_handle_valid(handle));
1393
1394	if (ext4_has_inline_data(inode))
1395	return ext4_write_inline_data_end(inode, pos, len, copied,
1396	folio);
1397
1398	if (unlikely(copied < len) && !folio_test_uptodate(folio)) {
1399	copied = 0;
1400	ext4_journalled_zero_new_buffers(handle, inode, folio,
1401	from, to);
1402	} else {
1403	if (unlikely(copied < len))
1404	ext4_journalled_zero_new_buffers(handle, inode, folio,
1405	from: from + copied, to);
1406	ret = ext4_walk_page_buffers(handle, inode,
1407	folio_buffers(folio),
1408	from, to: from + copied, partial: &partial,
1409	fn: write_end_fn);
1410	if (!partial)
1411	folio_mark_uptodate(folio);
1412	}
1413	if (!verity)
1414	size_changed = ext4_update_inode_size(inode, newsize: pos + copied);
1415	EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1416	folio_unlock(folio);
1417	folio_put(folio);
1418
1419	if (old_size < pos && !verity)
1420	pagecache_isize_extended(inode, from: old_size, to: pos);
1421
1422	if (size_changed) {
1423	ret2 = ext4_mark_inode_dirty(handle, inode);
1424	if (!ret)
1425	ret = ret2;
1426	}
1427
1428	if (pos + len > inode->i_size && !verity && ext4_can_truncate(inode))
1429	/* if we have allocated more blocks and copied
1430	* less. We will have blocks allocated outside
1431	* inode->i_size. So truncate them
1432	*/
1433	ext4_orphan_add(handle, inode);
1434
1435	ret2 = ext4_journal_stop(handle);
1436	if (!ret)
1437	ret = ret2;
1438	if (pos + len > inode->i_size && !verity) {
1439	ext4_truncate_failed_write(inode);
1440	/*
1441	* If truncate failed early the inode might still be
1442	* on the orphan list; we need to make sure the inode
1443	* is removed from the orphan list in that case.
1444	*/
1445	if (inode->i_nlink)
1446	ext4_orphan_del(NULL, inode);
1447	}
1448
1449	return ret ? ret : copied;
1450	}
1451
1452	/*
1453	* Reserve space for a single cluster
1454	*/
1455	static int ext4_da_reserve_space(struct inode *inode)
1456	{
1457	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
1458	struct ext4_inode_info *ei = EXT4_I(inode);
1459	int ret;
1460
1461	/*
1462	* We will charge metadata quota at writeout time; this saves
1463	* us from metadata over-estimation, though we may go over by
1464	* a small amount in the end. Here we just reserve for data.
1465	*/
1466	ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
1467	if (ret)
1468	return ret;
1469
1470	spin_lock(lock: &ei->i_block_reservation_lock);
1471	if (ext4_claim_free_clusters(sbi, nclusters: 1, flags: 0)) {
1472	spin_unlock(lock: &ei->i_block_reservation_lock);
1473	dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
1474	return -ENOSPC;
1475	}
1476	ei->i_reserved_data_blocks++;
1477	trace_ext4_da_reserve_space(inode);
1478	spin_unlock(lock: &ei->i_block_reservation_lock);
1479
1480	return 0; /* success */
1481	}
1482
1483	void ext4_da_release_space(struct inode *inode, int to_free)
1484	{
1485	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
1486	struct ext4_inode_info *ei = EXT4_I(inode);
1487
1488	if (!to_free)
1489	return; /* Nothing to release, exit */
1490
1491	spin_lock(lock: &EXT4_I(inode)->i_block_reservation_lock);
1492
1493	trace_ext4_da_release_space(inode, freed_blocks: to_free);
1494	if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1495	/*
1496	* if there aren't enough reserved blocks, then the
1497	* counter is messed up somewhere. Since this
1498	* function is called from invalidate page, it's
1499	* harmless to return without any action.
1500	*/
1501	ext4_warning(inode->i_sb, "ext4_da_release_space: "
1502	"ino %lu, to_free %d with only %d reserved "
1503	"data blocks", inode->i_ino, to_free,
1504	ei->i_reserved_data_blocks);
1505	WARN_ON(1);
1506	to_free = ei->i_reserved_data_blocks;
1507	}
1508	ei->i_reserved_data_blocks -= to_free;
1509
1510	/* update fs dirty data blocks counter */
1511	percpu_counter_sub(fbc: &sbi->s_dirtyclusters_counter, amount: to_free);
1512
1513	spin_unlock(lock: &EXT4_I(inode)->i_block_reservation_lock);
1514
1515	dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
1516	}
1517
1518	/*
1519	* Delayed allocation stuff
1520	*/
1521
1522	struct mpage_da_data {
1523	/* These are input fields for ext4_do_writepages() */
1524	struct inode *inode;
1525	struct writeback_control *wbc;
1526	unsigned int can_map:1; /* Can writepages call map blocks? */
1527
1528	/* These are internal state of ext4_do_writepages() */
1529	pgoff_t first_page; /* The first page to write */
1530	pgoff_t next_page; /* Current page to examine */
1531	pgoff_t last_page; /* Last page to examine */
1532	/*
1533	* Extent to map - this can be after first_page because that can be
1534	* fully mapped. We somewhat abuse m_flags to store whether the extent
1535	* is delalloc or unwritten.
1536	*/
1537	struct ext4_map_blocks map;
1538	struct ext4_io_submit io_submit; /* IO submission data */
1539	unsigned int do_map:1;
1540	unsigned int scanned_until_end:1;
1541	unsigned int journalled_more_data:1;
1542	};
1543
1544	static void mpage_release_unused_pages(struct mpage_da_data *mpd,
1545	bool invalidate)
1546	{
1547	unsigned nr, i;
1548	pgoff_t index, end;
1549	struct folio_batch fbatch;
1550	struct inode *inode = mpd->inode;
1551	struct address_space *mapping = inode->i_mapping;
1552
1553	/* This is necessary when next_page == 0. */
1554	if (mpd->first_page >= mpd->next_page)
1555	return;
1556
1557	mpd->scanned_until_end = 0;
1558	index = mpd->first_page;
1559	end = mpd->next_page - 1;
1560	if (invalidate) {
1561	ext4_lblk_t start, last;
1562	start = index << (PAGE_SHIFT - inode->i_blkbits);
1563	last = end << (PAGE_SHIFT - inode->i_blkbits);
1564
1565	/*
1566	* avoid racing with extent status tree scans made by
1567	* ext4_insert_delayed_block()
1568	*/
1569	down_write(sem: &EXT4_I(inode)->i_data_sem);
1570	ext4_es_remove_extent(inode, lblk: start, len: last - start + 1);
1571	up_write(sem: &EXT4_I(inode)->i_data_sem);
1572	}
1573
1574	folio_batch_init(fbatch: &fbatch);
1575	while (index <= end) {
1576	nr = filemap_get_folios(mapping, start: &index, end, fbatch: &fbatch);
1577	if (nr == 0)
1578	break;
1579	for (i = 0; i < nr; i++) {
1580	struct folio *folio = fbatch.folios[i];
1581
1582	if (folio->index < mpd->first_page)
1583	continue;
1584	if (folio_next_index(folio) - 1 > end)
1585	continue;
1586	BUG_ON(!folio_test_locked(folio));
1587	BUG_ON(folio_test_writeback(folio));
1588	if (invalidate) {
1589	if (folio_mapped(folio))
1590	folio_clear_dirty_for_io(folio);
1591	block_invalidate_folio(folio, offset: 0,
1592	length: folio_size(folio));
1593	folio_clear_uptodate(folio);
1594	}
1595	folio_unlock(folio);
1596	}
1597	folio_batch_release(fbatch: &fbatch);
1598	}
1599	}
1600
1601	static void ext4_print_free_blocks(struct inode *inode)
1602	{
1603	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
1604	struct super_block *sb = inode->i_sb;
1605	struct ext4_inode_info *ei = EXT4_I(inode);
1606
1607	ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
1608	EXT4_C2B(EXT4_SB(inode->i_sb),
1609	ext4_count_free_clusters(sb)));
1610	ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
1611	ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
1612	(long long) EXT4_C2B(EXT4_SB(sb),
1613	percpu_counter_sum(&sbi->s_freeclusters_counter)));
1614	ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
1615	(long long) EXT4_C2B(EXT4_SB(sb),
1616	percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
1617	ext4_msg(sb, KERN_CRIT, "Block reservation details");
1618	ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1619	ei->i_reserved_data_blocks);
1620	return;
1621	}
1622
1623	/*
1624	* ext4_insert_delayed_block - adds a delayed block to the extents status
1625	* tree, incrementing the reserved cluster/block
1626	* count or making a pending reservation
1627	* where needed
1628	*
1629	* @inode - file containing the newly added block
1630	* @lblk - logical block to be added
1631	*
1632	* Returns 0 on success, negative error code on failure.
1633	*/
1634	static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
1635	{
1636	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
1637	int ret;
1638	bool allocated = false;
1639
1640	/*
1641	* If the cluster containing lblk is shared with a delayed,
1642	* written, or unwritten extent in a bigalloc file system, it's
1643	* already been accounted for and does not need to be reserved.
1644	* A pending reservation must be made for the cluster if it's
1645	* shared with a written or unwritten extent and doesn't already
1646	* have one. Written and unwritten extents can be purged from the
1647	* extents status tree if the system is under memory pressure, so
1648	* it's necessary to examine the extent tree if a search of the
1649	* extents status tree doesn't get a match.
1650	*/
1651	if (sbi->s_cluster_ratio == 1) {
1652	ret = ext4_da_reserve_space(inode);
1653	if (ret != 0) /* ENOSPC */
1654	return ret;
1655	} else { /* bigalloc */
1656	if (!ext4_es_scan_clu(inode, matching_fn: &ext4_es_is_delonly, lblk)) {
1657	if (!ext4_es_scan_clu(inode,
1658	matching_fn: &ext4_es_is_mapped, lblk)) {
1659	ret = ext4_clu_mapped(inode,
1660	EXT4_B2C(sbi, lblk));
1661	if (ret < 0)
1662	return ret;
1663	if (ret == 0) {
1664	ret = ext4_da_reserve_space(inode);
1665	if (ret != 0) /* ENOSPC */
1666	return ret;
1667	} else {
1668	allocated = true;
1669	}
1670	} else {
1671	allocated = true;
1672	}
1673	}
1674	}
1675
1676	ext4_es_insert_delayed_block(inode, lblk, allocated);
1677	return 0;
1678	}
1679
1680	/*
1681	* This function is grabs code from the very beginning of
1682	* ext4_map_blocks, but assumes that the caller is from delayed write
1683	* time. This function looks up the requested blocks and sets the
1684	* buffer delay bit under the protection of i_data_sem.
1685	*/
1686	static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
1687	struct ext4_map_blocks *map,
1688	struct buffer_head *bh)
1689	{
1690	struct extent_status es;
1691	int retval;
1692	sector_t invalid_block = ~((sector_t) 0xffff);
1693	#ifdef ES_AGGRESSIVE_TEST
1694	struct ext4_map_blocks orig_map;
1695
1696	memcpy(&orig_map, map, sizeof(*map));
1697	#endif
1698
1699	if (invalid_block < ext4_blocks_count(es: EXT4_SB(sb: inode->i_sb)->s_es))
1700	invalid_block = ~0;
1701
1702	map->m_flags = 0;
1703	ext_debug(inode, "max_blocks %u, logical block %lu\n", map->m_len,
1704	(unsigned long) map->m_lblk);
1705
1706	/* Lookup extent status tree firstly */
1707	if (ext4_es_lookup_extent(inode, lblk: iblock, NULL, es: &es)) {
1708	if (ext4_es_is_hole(es: &es))
1709	goto add_delayed;
1710
1711	/*
1712	* Delayed extent could be allocated by fallocate.
1713	* So we need to check it.
1714	*/
1715	if (ext4_es_is_delayed(es: &es) && !ext4_es_is_unwritten(es: &es)) {
1716	map_bh(bh, sb: inode->i_sb, block: invalid_block);
1717	set_buffer_new(bh);
1718	set_buffer_delay(bh);
1719	return 0;
1720	}
1721
1722	map->m_pblk = ext4_es_pblock(es: &es) + iblock - es.es_lblk;
1723	retval = es.es_len - (iblock - es.es_lblk);
1724	if (retval > map->m_len)
1725	retval = map->m_len;
1726	map->m_len = retval;
1727	if (ext4_es_is_written(es: &es))
1728	map->m_flags |= EXT4_MAP_MAPPED;
1729	else if (ext4_es_is_unwritten(es: &es))
1730	map->m_flags |= EXT4_MAP_UNWRITTEN;
1731	else
1732	BUG();
1733
1734	#ifdef ES_AGGRESSIVE_TEST
1735	ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0);
1736	#endif
1737	return retval;
1738	}
1739
1740	/*
1741	* Try to see if we can get the block without requesting a new
1742	* file system block.
1743	*/
1744	down_read(sem: &EXT4_I(inode)->i_data_sem);
1745	if (ext4_has_inline_data(inode))
1746	retval = 0;
1747	else if (ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))
1748	retval = ext4_ext_map_blocks(NULL, inode, map, flags: 0);
1749	else
1750	retval = ext4_ind_map_blocks(NULL, inode, map, flags: 0);
1751	if (retval < 0) {
1752	up_read(sem: &EXT4_I(inode)->i_data_sem);
1753	return retval;
1754	}
1755	if (retval > 0) {
1756	unsigned int status;
1757
1758	if (unlikely(retval != map->m_len)) {
1759	ext4_warning(inode->i_sb,
1760	"ES len assertion failed for inode "
1761	"%lu: retval %d != map->m_len %d",
1762	inode->i_ino, retval, map->m_len);
1763	WARN_ON(1);
1764	}
1765
1766	status = map->m_flags & EXT4_MAP_UNWRITTEN ?
1767	EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
1768	ext4_es_insert_extent(inode, lblk: map->m_lblk, len: map->m_len,
1769	pblk: map->m_pblk, status);
1770	up_read(sem: &EXT4_I(inode)->i_data_sem);
1771	return retval;
1772	}
1773	up_read(sem: &EXT4_I(inode)->i_data_sem);
1774
1775	add_delayed:
1776	down_write(sem: &EXT4_I(inode)->i_data_sem);
1777	retval = ext4_insert_delayed_block(inode, lblk: map->m_lblk);
1778	up_write(sem: &EXT4_I(inode)->i_data_sem);
1779	if (retval)
1780	return retval;
1781
1782	map_bh(bh, sb: inode->i_sb, block: invalid_block);
1783	set_buffer_new(bh);
1784	set_buffer_delay(bh);
1785	return retval;
1786	}
1787
1788	/*
1789	* This is a special get_block_t callback which is used by
1790	* ext4_da_write_begin(). It will either return mapped block or
1791	* reserve space for a single block.
1792	*
1793	* For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
1794	* We also have b_blocknr = -1 and b_bdev initialized properly
1795	*
1796	* For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
1797	* We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
1798	* initialized properly.
1799	*/
1800	int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
1801	struct buffer_head *bh, int create)
1802	{
1803	struct ext4_map_blocks map;
1804	int ret = 0;
1805
1806	BUG_ON(create == 0);
1807	BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
1808
1809	map.m_lblk = iblock;
1810	map.m_len = 1;
1811
1812	/*
1813	* first, we need to know whether the block is allocated already
1814	* preallocated blocks are unmapped but should treated
1815	* the same as allocated blocks.
1816	*/
1817	ret = ext4_da_map_blocks(inode, iblock, map: &map, bh);
1818	if (ret <= 0)
1819	return ret;
1820
1821	map_bh(bh, sb: inode->i_sb, block: map.m_pblk);
1822	ext4_update_bh_state(bh, flags: map.m_flags);
1823
1824	if (buffer_unwritten(bh)) {
1825	/* A delayed write to unwritten bh should be marked
1826	* new and mapped. Mapped ensures that we don't do
1827	* get_block multiple times when we write to the same
1828	* offset and new ensures that we do proper zero out
1829	* for partial write.
1830	*/
1831	set_buffer_new(bh);
1832	set_buffer_mapped(bh);
1833	}
1834	return 0;
1835	}
1836
1837	static void mpage_folio_done(struct mpage_da_data *mpd, struct folio *folio)
1838	{
1839	mpd->first_page += folio_nr_pages(folio);
1840	folio_unlock(folio);
1841	}
1842
1843	static int mpage_submit_folio(struct mpage_da_data *mpd, struct folio *folio)
1844	{
1845	size_t len;
1846	loff_t size;
1847	int err;
1848
1849	BUG_ON(folio->index != mpd->first_page);
1850	folio_clear_dirty_for_io(folio);
1851	/*
1852	* We have to be very careful here! Nothing protects writeback path
1853	* against i_size changes and the page can be writeably mapped into
1854	* page tables. So an application can be growing i_size and writing
1855	* data through mmap while writeback runs. folio_clear_dirty_for_io()
1856	* write-protects our page in page tables and the page cannot get
1857	* written to again until we release folio lock. So only after
1858	* folio_clear_dirty_for_io() we are safe to sample i_size for
1859	* ext4_bio_write_folio() to zero-out tail of the written page. We rely
1860	* on the barrier provided by folio_test_clear_dirty() in
1861	* folio_clear_dirty_for_io() to make sure i_size is really sampled only
1862	* after page tables are updated.
1863	*/
1864	size = i_size_read(inode: mpd->inode);
1865	len = folio_size(folio);
1866	if (folio_pos(folio) + len > size &&
1867	!ext4_verity_in_progress(inode: mpd->inode))
1868	len = size & ~PAGE_MASK;
1869	err = ext4_bio_write_folio(io: &mpd->io_submit, page: folio, len);
1870	if (!err)
1871	mpd->wbc->nr_to_write--;
1872
1873	return err;
1874	}
1875
1876	#define BH_FLAGS (BIT(BH_Unwritten) | BIT(BH_Delay))
1877
1878	/*
1879	* mballoc gives us at most this number of blocks...
1880	* XXX: That seems to be only a limitation of ext4_mb_normalize_request().
1881	* The rest of mballoc seems to handle chunks up to full group size.
1882	*/
1883	#define MAX_WRITEPAGES_EXTENT_LEN 2048
1884
1885	/*
1886	* mpage_add_bh_to_extent - try to add bh to extent of blocks to map
1887	*
1888	* @mpd - extent of blocks
1889	* @lblk - logical number of the block in the file
1890	* @bh - buffer head we want to add to the extent
1891	*
1892	* The function is used to collect contig. blocks in the same state. If the
1893	* buffer doesn't require mapping for writeback and we haven't started the
1894	* extent of buffers to map yet, the function returns 'true' immediately - the
1895	* caller can write the buffer right away. Otherwise the function returns true
1896	* if the block has been added to the extent, false if the block couldn't be
1897	* added.
1898	*/
1899	static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk,
1900	struct buffer_head *bh)
1901	{
1902	struct ext4_map_blocks *map = &mpd->map;
1903
1904	/* Buffer that doesn't need mapping for writeback? */
1905	if (!buffer_dirty(bh) || !buffer_mapped(bh) ||
1906	(!buffer_delay(bh) && !buffer_unwritten(bh))) {
1907	/* So far no extent to map => we write the buffer right away */
1908	if (map->m_len == 0)
1909	return true;
1910	return false;
1911	}
1912
1913	/* First block in the extent? */
1914	if (map->m_len == 0) {
1915	/* We cannot map unless handle is started... */
1916	if (!mpd->do_map)
1917	return false;
1918	map->m_lblk = lblk;
1919	map->m_len = 1;
1920	map->m_flags = bh->b_state & BH_FLAGS;
1921	return true;
1922	}
1923
1924	/* Don't go larger than mballoc is willing to allocate */
1925	if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN)
1926	return false;
1927
1928	/* Can we merge the block to our big extent? */
1929	if (lblk == map->m_lblk + map->m_len &&
1930	(bh->b_state & BH_FLAGS) == map->m_flags) {
1931	map->m_len++;
1932	return true;
1933	}
1934	return false;
1935	}
1936
1937	/*
1938	* mpage_process_page_bufs - submit page buffers for IO or add them to extent
1939	*
1940	* @mpd - extent of blocks for mapping
1941	* @head - the first buffer in the page
1942	* @bh - buffer we should start processing from
1943	* @lblk - logical number of the block in the file corresponding to @bh
1944	*
1945	* Walk through page buffers from @bh upto @head (exclusive) and either submit
1946	* the page for IO if all buffers in this page were mapped and there's no
1947	* accumulated extent of buffers to map or add buffers in the page to the
1948	* extent of buffers to map. The function returns 1 if the caller can continue
1949	* by processing the next page, 0 if it should stop adding buffers to the
1950	* extent to map because we cannot extend it anymore. It can also return value
1951	* < 0 in case of error during IO submission.
1952	*/
1953	static int mpage_process_page_bufs(struct mpage_da_data *mpd,
1954	struct buffer_head *head,
1955	struct buffer_head *bh,
1956	ext4_lblk_t lblk)
1957	{
1958	struct inode *inode = mpd->inode;
1959	int err;
1960	ext4_lblk_t blocks = (i_size_read(inode) + i_blocksize(node: inode) - 1)
1961	>> inode->i_blkbits;
1962
1963	if (ext4_verity_in_progress(inode))
1964	blocks = EXT_MAX_BLOCKS;
1965
1966	do {
1967	BUG_ON(buffer_locked(bh));
1968
1969	if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) {
1970	/* Found extent to map? */
1971	if (mpd->map.m_len)
1972	return 0;
1973	/* Buffer needs mapping and handle is not started? */
1974	if (!mpd->do_map)
1975	return 0;
1976	/* Everything mapped so far and we hit EOF */
1977	break;
1978	}
1979	} while (lblk++, (bh = bh->b_this_page) != head);
1980	/* So far everything mapped? Submit the page for IO. */
1981	if (mpd->map.m_len == 0) {
1982	err = mpage_submit_folio(mpd, folio: head->b_folio);
1983	if (err < 0)
1984	return err;
1985	mpage_folio_done(mpd, folio: head->b_folio);
1986	}
1987	if (lblk >= blocks) {
1988	mpd->scanned_until_end = 1;
1989	return 0;
1990	}
1991	return 1;
1992	}
1993
1994	/*
1995	* mpage_process_folio - update folio buffers corresponding to changed extent
1996	* and may submit fully mapped page for IO
1997	* @mpd: description of extent to map, on return next extent to map
1998	* @folio: Contains these buffers.
1999	* @m_lblk: logical block mapping.
2000	* @m_pblk: corresponding physical mapping.
2001	* @map_bh: determines on return whether this page requires any further
2002	* mapping or not.
2003	*
2004	* Scan given folio buffers corresponding to changed extent and update buffer
2005	* state according to new extent state.
2006	* We map delalloc buffers to their physical location, clear unwritten bits.
2007	* If the given folio is not fully mapped, we update @mpd to the next extent in
2008	* the given folio that needs mapping & return @map_bh as true.
2009	*/
2010	static int mpage_process_folio(struct mpage_da_data *mpd, struct folio *folio,
2011	ext4_lblk_t *m_lblk, ext4_fsblk_t *m_pblk,
2012	bool *map_bh)
2013	{
2014	struct buffer_head *head, *bh;
2015	ext4_io_end_t *io_end = mpd->io_submit.io_end;
2016	ext4_lblk_t lblk = *m_lblk;
2017	ext4_fsblk_t pblock = *m_pblk;
2018	int err = 0;
2019	int blkbits = mpd->inode->i_blkbits;
2020	ssize_t io_end_size = 0;
2021	struct ext4_io_end_vec *io_end_vec = ext4_last_io_end_vec(io_end);
2022
2023	bh = head = folio_buffers(folio);
2024	do {
2025	if (lblk < mpd->map.m_lblk)
2026	continue;
2027	if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
2028	/*
2029	* Buffer after end of mapped extent.
2030	* Find next buffer in the folio to map.
2031	*/
2032	mpd->map.m_len = 0;
2033	mpd->map.m_flags = 0;
2034	io_end_vec->size += io_end_size;
2035
2036	err = mpage_process_page_bufs(mpd, head, bh, lblk);
2037	if (err > 0)
2038	err = 0;
2039	if (!err && mpd->map.m_len && mpd->map.m_lblk > lblk) {
2040	io_end_vec = ext4_alloc_io_end_vec(io_end);
2041	if (IS_ERR(ptr: io_end_vec)) {
2042	err = PTR_ERR(ptr: io_end_vec);
2043	goto out;
2044	}
2045	io_end_vec->offset = (loff_t)mpd->map.m_lblk << blkbits;
2046	}
2047	*map_bh = true;
2048	goto out;
2049	}
2050	if (buffer_delay(bh)) {
2051	clear_buffer_delay(bh);
2052	bh->b_blocknr = pblock++;
2053	}
2054	clear_buffer_unwritten(bh);
2055	io_end_size += (1 << blkbits);
2056	} while (lblk++, (bh = bh->b_this_page) != head);
2057
2058	io_end_vec->size += io_end_size;
2059	*map_bh = false;
2060	out:
2061	*m_lblk = lblk;
2062	*m_pblk = pblock;
2063	return err;
2064	}
2065
2066	/*
2067	* mpage_map_buffers - update buffers corresponding to changed extent and
2068	* submit fully mapped pages for IO
2069	*
2070	* @mpd - description of extent to map, on return next extent to map
2071	*
2072	* Scan buffers corresponding to changed extent (we expect corresponding pages
2073	* to be already locked) and update buffer state according to new extent state.
2074	* We map delalloc buffers to their physical location, clear unwritten bits,
2075	* and mark buffers as uninit when we perform writes to unwritten extents
2076	* and do extent conversion after IO is finished. If the last page is not fully
2077	* mapped, we update @map to the next extent in the last page that needs
2078	* mapping. Otherwise we submit the page for IO.
2079	*/
2080	static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
2081	{
2082	struct folio_batch fbatch;
2083	unsigned nr, i;
2084	struct inode *inode = mpd->inode;
2085	int bpp_bits = PAGE_SHIFT - inode->i_blkbits;
2086	pgoff_t start, end;
2087	ext4_lblk_t lblk;
2088	ext4_fsblk_t pblock;
2089	int err;
2090	bool map_bh = false;
2091
2092	start = mpd->map.m_lblk >> bpp_bits;
2093	end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits;
2094	lblk = start << bpp_bits;
2095	pblock = mpd->map.m_pblk;
2096
2097	folio_batch_init(fbatch: &fbatch);
2098	while (start <= end) {
2099	nr = filemap_get_folios(mapping: inode->i_mapping, start: &start, end, fbatch: &fbatch);
2100	if (nr == 0)
2101	break;
2102	for (i = 0; i < nr; i++) {
2103	struct folio *folio = fbatch.folios[i];
2104
2105	err = mpage_process_folio(mpd, folio, m_lblk: &lblk, m_pblk: &pblock,
2106	map_bh: &map_bh);
2107	/*
2108	* If map_bh is true, means page may require further bh
2109	* mapping, or maybe the page was submitted for IO.
2110	* So we return to call further extent mapping.
2111	*/
2112	if (err < 0 || map_bh)
2113	goto out;
2114	/* Page fully mapped - let IO run! */
2115	err = mpage_submit_folio(mpd, folio);
2116	if (err < 0)
2117	goto out;
2118	mpage_folio_done(mpd, folio);
2119	}
2120	folio_batch_release(fbatch: &fbatch);
2121	}
2122	/* Extent fully mapped and matches with page boundary. We are done. */
2123	mpd->map.m_len = 0;
2124	mpd->map.m_flags = 0;
2125	return 0;
2126	out:
2127	folio_batch_release(fbatch: &fbatch);
2128	return err;
2129	}
2130
2131	static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd)
2132	{
2133	struct inode *inode = mpd->inode;
2134	struct ext4_map_blocks *map = &mpd->map;
2135	int get_blocks_flags;
2136	int err, dioread_nolock;
2137
2138	trace_ext4_da_write_pages_extent(inode, map);
2139	/*
2140	* Call ext4_map_blocks() to allocate any delayed allocation blocks, or
2141	* to convert an unwritten extent to be initialized (in the case
2142	* where we have written into one or more preallocated blocks). It is
2143	* possible that we're going to need more metadata blocks than
2144	* previously reserved. However we must not fail because we're in
2145	* writeback and there is nothing we can do about it so it might result
2146	* in data loss. So use reserved blocks to allocate metadata if
2147	* possible.
2148	*
2149	* We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if
2150	* the blocks in question are delalloc blocks. This indicates
2151	* that the blocks and quotas has already been checked when
2152	* the data was copied into the page cache.
2153	*/
2154	get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
2155	EXT4_GET_BLOCKS_METADATA_NOFAIL |
2156	EXT4_GET_BLOCKS_IO_SUBMIT;
2157	dioread_nolock = ext4_should_dioread_nolock(inode);
2158	if (dioread_nolock)
2159	get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
2160	if (map->m_flags & BIT(BH_Delay))
2161	get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
2162
2163	err = ext4_map_blocks(handle, inode, map, flags: get_blocks_flags);
2164	if (err < 0)
2165	return err;
2166	if (dioread_nolock && (map->m_flags & EXT4_MAP_UNWRITTEN)) {
2167	if (!mpd->io_submit.io_end->handle &&
2168	ext4_handle_valid(handle)) {
2169	mpd->io_submit.io_end->handle = handle->h_rsv_handle;
2170	handle->h_rsv_handle = NULL;
2171	}
2172	ext4_set_io_unwritten_flag(inode, io_end: mpd->io_submit.io_end);
2173	}
2174
2175	BUG_ON(map->m_len == 0);
2176	return 0;
2177	}
2178
2179	/*
2180	* mpage_map_and_submit_extent - map extent starting at mpd->lblk of length
2181	* mpd->len and submit pages underlying it for IO
2182	*
2183	* @handle - handle for journal operations
2184	* @mpd - extent to map
2185	* @give_up_on_write - we set this to true iff there is a fatal error and there
2186	* is no hope of writing the data. The caller should discard
2187	* dirty pages to avoid infinite loops.
2188	*
2189	* The function maps extent starting at mpd->lblk of length mpd->len. If it is
2190	* delayed, blocks are allocated, if it is unwritten, we may need to convert
2191	* them to initialized or split the described range from larger unwritten
2192	* extent. Note that we need not map all the described range since allocation
2193	* can return less blocks or the range is covered by more unwritten extents. We
2194	* cannot map more because we are limited by reserved transaction credits. On
2195	* the other hand we always make sure that the last touched page is fully
2196	* mapped so that it can be written out (and thus forward progress is
2197	* guaranteed). After mapping we submit all mapped pages for IO.
2198	*/
2199	static int mpage_map_and_submit_extent(handle_t *handle,
2200	struct mpage_da_data *mpd,
2201	bool *give_up_on_write)
2202	{
2203	struct inode *inode = mpd->inode;
2204	struct ext4_map_blocks *map = &mpd->map;
2205	int err;
2206	loff_t disksize;
2207	int progress = 0;
2208	ext4_io_end_t *io_end = mpd->io_submit.io_end;
2209	struct ext4_io_end_vec *io_end_vec;
2210
2211	io_end_vec = ext4_alloc_io_end_vec(io_end);
2212	if (IS_ERR(ptr: io_end_vec))
2213	return PTR_ERR(ptr: io_end_vec);
2214	io_end_vec->offset = ((loff_t)map->m_lblk) << inode->i_blkbits;
2215	do {
2216	err = mpage_map_one_extent(handle, mpd);
2217	if (err < 0) {
2218	struct super_block *sb = inode->i_sb;
2219
2220	if (ext4_forced_shutdown(sb))
2221	goto invalidate_dirty_pages;
2222	/*
2223	* Let the uper layers retry transient errors.
2224	* In the case of ENOSPC, if ext4_count_free_blocks()
2225	* is non-zero, a commit should free up blocks.
2226	*/
2227	if ((err == -ENOMEM) ||
2228	(err == -ENOSPC && ext4_count_free_clusters(sb))) {
2229	if (progress)
2230	goto update_disksize;
2231	return err;
2232	}
2233	ext4_msg(sb, KERN_CRIT,
2234	"Delayed block allocation failed for "
2235	"inode %lu at logical offset %llu with"
2236	" max blocks %u with error %d",
2237	inode->i_ino,
2238	(unsigned long long)map->m_lblk,
2239	(unsigned)map->m_len, -err);
2240	ext4_msg(sb, KERN_CRIT,
2241	"This should not happen!! Data will "
2242	"be lost\n");
2243	if (err == -ENOSPC)
2244	ext4_print_free_blocks(inode);
2245	invalidate_dirty_pages:
2246	*give_up_on_write = true;
2247	return err;
2248	}
2249	progress = 1;
2250	/*
2251	* Update buffer state, submit mapped pages, and get us new
2252	* extent to map
2253	*/
2254	err = mpage_map_and_submit_buffers(mpd);
2255	if (err < 0)
2256	goto update_disksize;
2257	} while (map->m_len);
2258
2259	update_disksize:
2260	/*
2261	* Update on-disk size after IO is submitted. Races with
2262	* truncate are avoided by checking i_size under i_data_sem.
2263	*/
2264	disksize = ((loff_t)mpd->first_page) << PAGE_SHIFT;
2265	if (disksize > READ_ONCE(EXT4_I(inode)->i_disksize)) {
2266	int err2;
2267	loff_t i_size;
2268
2269	down_write(sem: &EXT4_I(inode)->i_data_sem);
2270	i_size = i_size_read(inode);
2271	if (disksize > i_size)
2272	disksize = i_size;
2273	if (disksize > EXT4_I(inode)->i_disksize)
2274	EXT4_I(inode)->i_disksize = disksize;
2275	up_write(sem: &EXT4_I(inode)->i_data_sem);
2276	err2 = ext4_mark_inode_dirty(handle, inode);
2277	if (err2) {
2278	ext4_error_err(inode->i_sb, -err2,
2279	"Failed to mark inode %lu dirty",
2280	inode->i_ino);
2281	}
2282	if (!err)
2283	err = err2;
2284	}
2285	return err;
2286	}
2287
2288	/*
2289	* Calculate the total number of credits to reserve for one writepages
2290	* iteration. This is called from ext4_writepages(). We map an extent of
2291	* up to MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping
2292	* the last partial page. So in total we can map MAX_WRITEPAGES_EXTENT_LEN +
2293	* bpp - 1 blocks in bpp different extents.
2294	*/
2295	static int ext4_da_writepages_trans_blocks(struct inode *inode)
2296	{
2297	int bpp = ext4_journal_blocks_per_page(inode);
2298
2299	return ext4_meta_trans_blocks(inode,
2300	MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, pextents: bpp);
2301	}
2302
2303	static int ext4_journal_folio_buffers(handle_t *handle, struct folio *folio,
2304	size_t len)
2305	{
2306	struct buffer_head *page_bufs = folio_buffers(folio);
2307	struct inode *inode = folio->mapping->host;
2308	int ret, err;
2309
2310	ret = ext4_walk_page_buffers(handle, inode, head: page_bufs, from: 0, to: len,
2311	NULL, fn: do_journal_get_write_access);
2312	err = ext4_walk_page_buffers(handle, inode, head: page_bufs, from: 0, to: len,
2313	NULL, fn: write_end_fn);
2314	if (ret == 0)
2315	ret = err;
2316	err = ext4_jbd2_inode_add_write(handle, inode, start_byte: folio_pos(folio), length: len);
2317	if (ret == 0)
2318	ret = err;
2319	EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
2320
2321	return ret;
2322	}
2323
2324	static int mpage_journal_page_buffers(handle_t *handle,
2325	struct mpage_da_data *mpd,
2326	struct folio *folio)
2327	{
2328	struct inode *inode = mpd->inode;
2329	loff_t size = i_size_read(inode);
2330	size_t len = folio_size(folio);
2331
2332	folio_clear_checked(folio);
2333	mpd->wbc->nr_to_write--;
2334
2335	if (folio_pos(folio) + len > size &&
2336	!ext4_verity_in_progress(inode))
2337	len = size - folio_pos(folio);
2338
2339	return ext4_journal_folio_buffers(handle, folio, len);
2340	}
2341
2342	/*
2343	* mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages
2344	* needing mapping, submit mapped pages
2345	*
2346	* @mpd - where to look for pages
2347	*
2348	* Walk dirty pages in the mapping. If they are fully mapped, submit them for
2349	* IO immediately. If we cannot map blocks, we submit just already mapped
2350	* buffers in the page for IO and keep page dirty. When we can map blocks and
2351	* we find a page which isn't mapped we start accumulating extent of buffers
2352	* underlying these pages that needs mapping (formed by either delayed or
2353	* unwritten buffers). We also lock the pages containing these buffers. The
2354	* extent found is returned in @mpd structure (starting at mpd->lblk with
2355	* length mpd->len blocks).
2356	*
2357	* Note that this function can attach bios to one io_end structure which are
2358	* neither logically nor physically contiguous. Although it may seem as an
2359	* unnecessary complication, it is actually inevitable in blocksize < pagesize
2360	* case as we need to track IO to all buffers underlying a page in one io_end.
2361	*/
2362	static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
2363	{
2364	struct address_space *mapping = mpd->inode->i_mapping;
2365	struct folio_batch fbatch;
2366	unsigned int nr_folios;
2367	pgoff_t index = mpd->first_page;
2368	pgoff_t end = mpd->last_page;
2369	xa_mark_t tag;
2370	int i, err = 0;
2371	int blkbits = mpd->inode->i_blkbits;
2372	ext4_lblk_t lblk;
2373	struct buffer_head *head;
2374	handle_t *handle = NULL;
2375	int bpp = ext4_journal_blocks_per_page(inode: mpd->inode);
2376
2377	if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages)
2378	tag = PAGECACHE_TAG_TOWRITE;
2379	else
2380	tag = PAGECACHE_TAG_DIRTY;
2381
2382	mpd->map.m_len = 0;
2383	mpd->next_page = index;
2384	if (ext4_should_journal_data(inode: mpd->inode)) {
2385	handle = ext4_journal_start(mpd->inode, EXT4_HT_WRITE_PAGE,
2386	bpp);
2387	if (IS_ERR(ptr: handle))
2388	return PTR_ERR(ptr: handle);
2389	}
2390	folio_batch_init(fbatch: &fbatch);
2391	while (index <= end) {
2392	nr_folios = filemap_get_folios_tag(mapping, start: &index, end,
2393	tag, fbatch: &fbatch);
2394	if (nr_folios == 0)
2395	break;
2396
2397	for (i = 0; i < nr_folios; i++) {
2398	struct folio *folio = fbatch.folios[i];
2399
2400	/*
2401	* Accumulated enough dirty pages? This doesn't apply
2402	* to WB_SYNC_ALL mode. For integrity sync we have to
2403	* keep going because someone may be concurrently
2404	* dirtying pages, and we might have synced a lot of
2405	* newly appeared dirty pages, but have not synced all
2406	* of the old dirty pages.
2407	*/
2408	if (mpd->wbc->sync_mode == WB_SYNC_NONE &&
2409	mpd->wbc->nr_to_write <=
2410	mpd->map.m_len >> (PAGE_SHIFT - blkbits))
2411	goto out;
2412
2413	/* If we can't merge this page, we are done. */
2414	if (mpd->map.m_len > 0 && mpd->next_page != folio->index)
2415	goto out;
2416
2417	if (handle) {
2418	err = ext4_journal_ensure_credits(handle, credits: bpp,
2419	revoke_creds: 0);
2420	if (err < 0)
2421	goto out;
2422	}
2423
2424	folio_lock(folio);
2425	/*
2426	* If the page is no longer dirty, or its mapping no
2427	* longer corresponds to inode we are writing (which
2428	* means it has been truncated or invalidated), or the
2429	* page is already under writeback and we are not doing
2430	* a data integrity writeback, skip the page
2431	*/
2432	if (!folio_test_dirty(folio) ||
2433	(folio_test_writeback(folio) &&
2434	(mpd->wbc->sync_mode == WB_SYNC_NONE)) ||
2435	unlikely(folio->mapping != mapping)) {
2436	folio_unlock(folio);
2437	continue;
2438	}
2439
2440	folio_wait_writeback(folio);
2441	BUG_ON(folio_test_writeback(folio));
2442
2443	/*
2444	* Should never happen but for buggy code in
2445	* other subsystems that call
2446	* set_page_dirty() without properly warning
2447	* the file system first. See [1] for more
2448	* information.
2449	*
2450	* [1] https://lore.kernel.org/linux-mm/20180103100430.GE4911@quack2.suse.cz
2451	*/
2452	if (!folio_buffers(folio)) {
2453	ext4_warning_inode(mpd->inode, "page %lu does not have buffers attached", folio->index);
2454	folio_clear_dirty(folio);
2455	folio_unlock(folio);
2456	continue;
2457	}
2458
2459	if (mpd->map.m_len == 0)
2460	mpd->first_page = folio->index;
2461	mpd->next_page = folio_next_index(folio);
2462	/*
2463	* Writeout when we cannot modify metadata is simple.
2464	* Just submit the page. For data=journal mode we
2465	* first handle writeout of the page for checkpoint and
2466	* only after that handle delayed page dirtying. This
2467	* makes sure current data is checkpointed to the final
2468	* location before possibly journalling it again which
2469	* is desirable when the page is frequently dirtied
2470	* through a pin.
2471	*/
2472	if (!mpd->can_map) {
2473	err = mpage_submit_folio(mpd, folio);
2474	if (err < 0)
2475	goto out;
2476	/* Pending dirtying of journalled data? */
2477	if (folio_test_checked(folio)) {
2478	err = mpage_journal_page_buffers(handle,
2479	mpd, folio);
2480	if (err < 0)
2481	goto out;
2482	mpd->journalled_more_data = 1;
2483	}
2484	mpage_folio_done(mpd, folio);
2485	} else {
2486	/* Add all dirty buffers to mpd */
2487	lblk = ((ext4_lblk_t)folio->index) <<
2488	(PAGE_SHIFT - blkbits);
2489	head = folio_buffers(folio);
2490	err = mpage_process_page_bufs(mpd, head, bh: head,
2491	lblk);
2492	if (err <= 0)
2493	goto out;
2494	err = 0;
2495	}
2496	}
2497	folio_batch_release(fbatch: &fbatch);
2498	cond_resched();
2499	}
2500	mpd->scanned_until_end = 1;
2501	if (handle)
2502	ext4_journal_stop(handle);
2503	return 0;
2504	out:
2505	folio_batch_release(fbatch: &fbatch);
2506	if (handle)
2507	ext4_journal_stop(handle);
2508	return err;
2509	}
2510
2511	static int ext4_do_writepages(struct mpage_da_data *mpd)
2512	{
2513	struct writeback_control *wbc = mpd->wbc;
2514	pgoff_t writeback_index = 0;
2515	long nr_to_write = wbc->nr_to_write;
2516	int range_whole = 0;
2517	int cycled = 1;
2518	handle_t *handle = NULL;
2519	struct inode *inode = mpd->inode;
2520	struct address_space *mapping = inode->i_mapping;
2521	int needed_blocks, rsv_blocks = 0, ret = 0;
2522	struct ext4_sb_info *sbi = EXT4_SB(sb: mapping->host->i_sb);
2523	struct blk_plug plug;
2524	bool give_up_on_write = false;
2525
2526	trace_ext4_writepages(inode, wbc);
2527
2528	/*
2529	* No pages to write? This is mainly a kludge to avoid starting
2530	* a transaction for special inodes like journal inode on last iput()
2531	* because that could violate lock ordering on umount
2532	*/
2533	if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2534	goto out_writepages;
2535
2536	/*
2537	* If the filesystem has aborted, it is read-only, so return
2538	* right away instead of dumping stack traces later on that
2539	* will obscure the real source of the problem. We test
2540	* fs shutdown state instead of sb->s_flag's SB_RDONLY because
2541	* the latter could be true if the filesystem is mounted
2542	* read-only, and in that case, ext4_writepages should
2543	* *never* be called, so if that ever happens, we would want
2544	* the stack trace.
2545	*/
2546	if (unlikely(ext4_forced_shutdown(mapping->host->i_sb))) {
2547	ret = -EROFS;
2548	goto out_writepages;
2549	}
2550
2551	/*
2552	* If we have inline data and arrive here, it means that
2553	* we will soon create the block for the 1st page, so
2554	* we'd better clear the inline data here.
2555	*/
2556	if (ext4_has_inline_data(inode)) {
2557	/* Just inode will be modified... */
2558	handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
2559	if (IS_ERR(ptr: handle)) {
2560	ret = PTR_ERR(ptr: handle);
2561	goto out_writepages;
2562	}
2563	BUG_ON(ext4_test_inode_state(inode,
2564	EXT4_STATE_MAY_INLINE_DATA));
2565	ext4_destroy_inline_data(handle, inode);
2566	ext4_journal_stop(handle);
2567	}
2568
2569	/*
2570	* data=journal mode does not do delalloc so we just need to writeout /
2571	* journal already mapped buffers. On the other hand we need to commit
2572	* transaction to make data stable. We expect all the data to be
2573	* already in the journal (the only exception are DMA pinned pages
2574	* dirtied behind our back) so we commit transaction here and run the
2575	* writeback loop to checkpoint them. The checkpointing is not actually
2576	* necessary to make data persistent *but* quite a few places (extent
2577	* shifting operations, fsverity, ...) depend on being able to drop
2578	* pagecache pages after calling filemap_write_and_wait() and for that
2579	* checkpointing needs to happen.
2580	*/
2581	if (ext4_should_journal_data(inode)) {
2582	mpd->can_map = 0;
2583	if (wbc->sync_mode == WB_SYNC_ALL)
2584	ext4_fc_commit(journal: sbi->s_journal,
2585	EXT4_I(inode)->i_datasync_tid);
2586	}
2587	mpd->journalled_more_data = 0;
2588
2589	if (ext4_should_dioread_nolock(inode)) {
2590	/*
2591	* We may need to convert up to one extent per block in
2592	* the page and we may dirty the inode.
2593	*/
2594	rsv_blocks = 1 + ext4_chunk_trans_blocks(inode,
2595	PAGE_SIZE >> inode->i_blkbits);
2596	}
2597
2598	if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2599	range_whole = 1;
2600
2601	if (wbc->range_cyclic) {
2602	writeback_index = mapping->writeback_index;
2603	if (writeback_index)
2604	cycled = 0;
2605	mpd->first_page = writeback_index;
2606	mpd->last_page = -1;
2607	} else {
2608	mpd->first_page = wbc->range_start >> PAGE_SHIFT;
2609	mpd->last_page = wbc->range_end >> PAGE_SHIFT;
2610	}
2611
2612	ext4_io_submit_init(io: &mpd->io_submit, wbc);
2613	retry:
2614	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2615	tag_pages_for_writeback(mapping, start: mpd->first_page,
2616	end: mpd->last_page);
2617	blk_start_plug(&plug);
2618
2619	/*
2620	* First writeback pages that don't need mapping - we can avoid
2621	* starting a transaction unnecessarily and also avoid being blocked
2622	* in the block layer on device congestion while having transaction
2623	* started.
2624	*/
2625	mpd->do_map = 0;
2626	mpd->scanned_until_end = 0;
2627	mpd->io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
2628	if (!mpd->io_submit.io_end) {
2629	ret = -ENOMEM;
2630	goto unplug;
2631	}
2632	ret = mpage_prepare_extent_to_map(mpd);
2633	/* Unlock pages we didn't use */
2634	mpage_release_unused_pages(mpd, invalidate: false);
2635	/* Submit prepared bio */
2636	ext4_io_submit(io: &mpd->io_submit);
2637	ext4_put_io_end_defer(io_end: mpd->io_submit.io_end);
2638	mpd->io_submit.io_end = NULL;
2639	if (ret < 0)
2640	goto unplug;
2641
2642	while (!mpd->scanned_until_end && wbc->nr_to_write > 0) {
2643	/* For each extent of pages we use new io_end */
2644	mpd->io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
2645	if (!mpd->io_submit.io_end) {
2646	ret = -ENOMEM;
2647	break;
2648	}
2649
2650	WARN_ON_ONCE(!mpd->can_map);
2651	/*
2652	* We have two constraints: We find one extent to map and we
2653	* must always write out whole page (makes a difference when
2654	* blocksize < pagesize) so that we don't block on IO when we
2655	* try to write out the rest of the page. Journalled mode is
2656	* not supported by delalloc.
2657	*/
2658	BUG_ON(ext4_should_journal_data(inode));
2659	needed_blocks = ext4_da_writepages_trans_blocks(inode);
2660
2661	/* start a new transaction */
2662	handle = ext4_journal_start_with_reserve(inode,
2663	EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks);
2664	if (IS_ERR(ptr: handle)) {
2665	ret = PTR_ERR(ptr: handle);
2666	ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
2667	"%ld pages, ino %lu; err %d", __func__,
2668	wbc->nr_to_write, inode->i_ino, ret);
2669	/* Release allocated io_end */
2670	ext4_put_io_end(io_end: mpd->io_submit.io_end);
2671	mpd->io_submit.io_end = NULL;
2672	break;
2673	}
2674	mpd->do_map = 1;
2675
2676	trace_ext4_da_write_pages(inode, first_page: mpd->first_page, wbc);
2677	ret = mpage_prepare_extent_to_map(mpd);
2678	if (!ret && mpd->map.m_len)
2679	ret = mpage_map_and_submit_extent(handle, mpd,
2680	give_up_on_write: &give_up_on_write);
2681	/*
2682	* Caution: If the handle is synchronous,
2683	* ext4_journal_stop() can wait for transaction commit
2684	* to finish which may depend on writeback of pages to
2685	* complete or on page lock to be released. In that
2686	* case, we have to wait until after we have
2687	* submitted all the IO, released page locks we hold,
2688	* and dropped io_end reference (for extent conversion
2689	* to be able to complete) before stopping the handle.
2690	*/
2691	if (!ext4_handle_valid(handle) || handle->h_sync == 0) {
2692	ext4_journal_stop(handle);
2693	handle = NULL;
2694	mpd->do_map = 0;
2695	}
2696	/* Unlock pages we didn't use */
2697	mpage_release_unused_pages(mpd, invalidate: give_up_on_write);
2698	/* Submit prepared bio */
2699	ext4_io_submit(io: &mpd->io_submit);
2700
2701	/*
2702	* Drop our io_end reference we got from init. We have
2703	* to be careful and use deferred io_end finishing if
2704	* we are still holding the transaction as we can
2705	* release the last reference to io_end which may end
2706	* up doing unwritten extent conversion.
2707	*/
2708	if (handle) {
2709	ext4_put_io_end_defer(io_end: mpd->io_submit.io_end);
2710	ext4_journal_stop(handle);
2711	} else
2712	ext4_put_io_end(io_end: mpd->io_submit.io_end);
2713	mpd->io_submit.io_end = NULL;
2714
2715	if (ret == -ENOSPC && sbi->s_journal) {
2716	/*
2717	* Commit the transaction which would
2718	* free blocks released in the transaction
2719	* and try again
2720	*/
2721	jbd2_journal_force_commit_nested(sbi->s_journal);
2722	ret = 0;
2723	continue;
2724	}
2725	/* Fatal error - ENOMEM, EIO... */
2726	if (ret)
2727	break;
2728	}
2729	unplug:
2730	blk_finish_plug(&plug);
2731	if (!ret && !cycled && wbc->nr_to_write > 0) {
2732	cycled = 1;
2733	mpd->last_page = writeback_index - 1;
2734	mpd->first_page = 0;
2735	goto retry;
2736	}
2737
2738	/* Update index */
2739	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2740	/*
2741	* Set the writeback_index so that range_cyclic
2742	* mode will write it back later
2743	*/
2744	mapping->writeback_index = mpd->first_page;
2745
2746	out_writepages:
2747	trace_ext4_writepages_result(inode, wbc, ret,
2748	pages_written: nr_to_write - wbc->nr_to_write);
2749	return ret;
2750	}
2751
2752	static int ext4_writepages(struct address_space *mapping,
2753	struct writeback_control *wbc)
2754	{
2755	struct super_block *sb = mapping->host->i_sb;
2756	struct mpage_da_data mpd = {
2757	.inode = mapping->host,
2758	.wbc = wbc,
2759	.can_map = 1,
2760	};
2761	int ret;
2762	int alloc_ctx;
2763
2764	if (unlikely(ext4_forced_shutdown(sb)))
2765	return -EIO;
2766
2767	alloc_ctx = ext4_writepages_down_read(sb);
2768	ret = ext4_do_writepages(mpd: &mpd);
2769	/*
2770	* For data=journal writeback we could have come across pages marked
2771	* for delayed dirtying (PageChecked) which were just added to the
2772	* running transaction. Try once more to get them to stable storage.
2773	*/
2774	if (!ret && mpd.journalled_more_data)
2775	ret = ext4_do_writepages(mpd: &mpd);
2776	ext4_writepages_up_read(sb, ctx: alloc_ctx);
2777
2778	return ret;
2779	}
2780
2781	int ext4_normal_submit_inode_data_buffers(struct jbd2_inode *jinode)
2782	{
2783	struct writeback_control wbc = {
2784	.sync_mode = WB_SYNC_ALL,
2785	.nr_to_write = LONG_MAX,
2786	.range_start = jinode->i_dirty_start,
2787	.range_end = jinode->i_dirty_end,
2788	};
2789	struct mpage_da_data mpd = {
2790	.inode = jinode->i_vfs_inode,
2791	.wbc = &wbc,
2792	.can_map = 0,
2793	};
2794	return ext4_do_writepages(mpd: &mpd);
2795	}
2796
2797	static int ext4_dax_writepages(struct address_space *mapping,
2798	struct writeback_control *wbc)
2799	{
2800	int ret;
2801	long nr_to_write = wbc->nr_to_write;
2802	struct inode *inode = mapping->host;
2803	int alloc_ctx;
2804
2805	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
2806	return -EIO;
2807
2808	alloc_ctx = ext4_writepages_down_read(sb: inode->i_sb);
2809	trace_ext4_writepages(inode, wbc);
2810
2811	ret = dax_writeback_mapping_range(mapping,
2812	dax_dev: EXT4_SB(sb: inode->i_sb)->s_daxdev, wbc);
2813	trace_ext4_writepages_result(inode, wbc, ret,
2814	pages_written: nr_to_write - wbc->nr_to_write);
2815	ext4_writepages_up_read(sb: inode->i_sb, ctx: alloc_ctx);
2816	return ret;
2817	}
2818
2819	static int ext4_nonda_switch(struct super_block *sb)
2820	{
2821	s64 free_clusters, dirty_clusters;
2822	struct ext4_sb_info *sbi = EXT4_SB(sb);
2823
2824	/*
2825	* switch to non delalloc mode if we are running low
2826	* on free block. The free block accounting via percpu
2827	* counters can get slightly wrong with percpu_counter_batch getting
2828	* accumulated on each CPU without updating global counters
2829	* Delalloc need an accurate free block accounting. So switch
2830	* to non delalloc when we are near to error range.
2831	*/
2832	free_clusters =
2833	percpu_counter_read_positive(fbc: &sbi->s_freeclusters_counter);
2834	dirty_clusters =
2835	percpu_counter_read_positive(fbc: &sbi->s_dirtyclusters_counter);
2836	/*
2837	* Start pushing delalloc when 1/2 of free blocks are dirty.
2838	*/
2839	if (dirty_clusters && (free_clusters < 2 * dirty_clusters))
2840	try_to_writeback_inodes_sb(sb, reason: WB_REASON_FS_FREE_SPACE);
2841
2842	if (2 * free_clusters < 3 * dirty_clusters ||
2843	free_clusters < (dirty_clusters + EXT4_FREECLUSTERS_WATERMARK)) {
2844	/*
2845	* free block count is less than 150% of dirty blocks
2846	* or free blocks is less than watermark
2847	*/
2848	return 1;
2849	}
2850	return 0;
2851	}
2852
2853	static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2854	loff_t pos, unsigned len,
2855	struct page **pagep, void **fsdata)
2856	{
2857	int ret, retries = 0;
2858	struct folio *folio;
2859	pgoff_t index;
2860	struct inode *inode = mapping->host;
2861
2862	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
2863	return -EIO;
2864
2865	index = pos >> PAGE_SHIFT;
2866
2867	if (ext4_nonda_switch(sb: inode->i_sb) || ext4_verity_in_progress(inode)) {
2868	*fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2869	return ext4_write_begin(file, mapping, pos,
2870	len, pagep, fsdata);
2871	}
2872	*fsdata = (void *)0;
2873	trace_ext4_da_write_begin(inode, pos, len);
2874
2875	if (ext4_test_inode_state(inode, bit: EXT4_STATE_MAY_INLINE_DATA)) {
2876	ret = ext4_da_write_inline_data_begin(mapping, inode, pos, len,
2877	pagep, fsdata);
2878	if (ret < 0)
2879	return ret;
2880	if (ret == 1)
2881	return 0;
2882	}
2883
2884	retry:
2885	folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
2886	gfp: mapping_gfp_mask(mapping));
2887	if (IS_ERR(ptr: folio))
2888	return PTR_ERR(ptr: folio);
2889
2890	/* In case writeback began while the folio was unlocked */
2891	folio_wait_stable(folio);
2892
2893	#ifdef CONFIG_FS_ENCRYPTION
2894	ret = ext4_block_write_begin(folio, pos, len, get_block: ext4_da_get_block_prep);
2895	#else
2896	ret = __block_write_begin(&folio->page, pos, len, ext4_da_get_block_prep);
2897	#endif
2898	if (ret < 0) {
2899	folio_unlock(folio);
2900	folio_put(folio);
2901	/*
2902	* block_write_begin may have instantiated a few blocks
2903	* outside i_size. Trim these off again. Don't need
2904	* i_size_read because we hold inode lock.
2905	*/
2906	if (pos + len > inode->i_size)
2907	ext4_truncate_failed_write(inode);
2908
2909	if (ret == -ENOSPC &&
2910	ext4_should_retry_alloc(sb: inode->i_sb, retries: &retries))
2911	goto retry;
2912	return ret;
2913	}
2914
2915	*pagep = &folio->page;
2916	return ret;
2917	}
2918
2919	/*
2920	* Check if we should update i_disksize
2921	* when write to the end of file but not require block allocation
2922	*/
2923	static int ext4_da_should_update_i_disksize(struct folio *folio,
2924	unsigned long offset)
2925	{
2926	struct buffer_head *bh;
2927	struct inode *inode = folio->mapping->host;
2928	unsigned int idx;
2929	int i;
2930
2931	bh = folio_buffers(folio);
2932	idx = offset >> inode->i_blkbits;
2933
2934	for (i = 0; i < idx; i++)
2935	bh = bh->b_this_page;
2936
2937	if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
2938	return 0;
2939	return 1;
2940	}
2941
2942	static int ext4_da_do_write_end(struct address_space *mapping,
2943	loff_t pos, unsigned len, unsigned copied,
2944	struct folio *folio)
2945	{
2946	struct inode *inode = mapping->host;
2947	loff_t old_size = inode->i_size;
2948	bool disksize_changed = false;
2949	loff_t new_i_size;
2950
2951	/*
2952	* block_write_end() will mark the inode as dirty with I_DIRTY_PAGES
2953	* flag, which all that's needed to trigger page writeback.
2954	*/
2955	copied = block_write_end(NULL, mapping, pos, len, copied,
2956	&folio->page, NULL);
2957	new_i_size = pos + copied;
2958
2959	/*
2960	* It's important to update i_size while still holding folio lock,
2961	* because folio writeout could otherwise come in and zero beyond
2962	* i_size.
2963	*
2964	* Since we are holding inode lock, we are sure i_disksize <=
2965	* i_size. We also know that if i_disksize < i_size, there are
2966	* delalloc writes pending in the range up to i_size. If the end of
2967	* the current write is <= i_size, there's no need to touch
2968	* i_disksize since writeback will push i_disksize up to i_size
2969	* eventually. If the end of the current write is > i_size and
2970	* inside an allocated block which ext4_da_should_update_i_disksize()
2971	* checked, we need to update i_disksize here as certain
2972	* ext4_writepages() paths not allocating blocks and update i_disksize.
2973	*/
2974	if (new_i_size > inode->i_size) {
2975	unsigned long end;
2976
2977	i_size_write(inode, i_size: new_i_size);
2978	end = (new_i_size - 1) & (PAGE_SIZE - 1);
2979	if (copied && ext4_da_should_update_i_disksize(folio, offset: end)) {
2980	ext4_update_i_disksize(inode, newsize: new_i_size);
2981	disksize_changed = true;
2982	}
2983	}
2984
2985	folio_unlock(folio);
2986	folio_put(folio);
2987
2988	if (old_size < pos)
2989	pagecache_isize_extended(inode, from: old_size, to: pos);
2990
2991	if (disksize_changed) {
2992	handle_t *handle;
2993
2994	handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
2995	if (IS_ERR(ptr: handle))
2996	return PTR_ERR(ptr: handle);
2997	ext4_mark_inode_dirty(handle, inode);
2998	ext4_journal_stop(handle);
2999	}
3000
3001	return copied;
3002	}
3003
3004	static int ext4_da_write_end(struct file *file,
3005	struct address_space *mapping,
3006	loff_t pos, unsigned len, unsigned copied,
3007	struct page *page, void *fsdata)
3008	{
3009	struct inode *inode = mapping->host;
3010	int write_mode = (int)(unsigned long)fsdata;
3011	struct folio *folio = page_folio(page);
3012
3013	if (write_mode == FALL_BACK_TO_NONDELALLOC)
3014	return ext4_write_end(file, mapping, pos,
3015	len, copied, page: &folio->page, fsdata);
3016
3017	trace_ext4_da_write_end(inode, pos, len, copied);
3018
3019	if (write_mode != CONVERT_INLINE_DATA &&
3020	ext4_test_inode_state(inode, bit: EXT4_STATE_MAY_INLINE_DATA) &&
3021	ext4_has_inline_data(inode))
3022	return ext4_write_inline_data_end(inode, pos, len, copied,
3023	folio);
3024
3025	if (unlikely(copied < len) && !folio_test_uptodate(folio))
3026	copied = 0;
3027
3028	return ext4_da_do_write_end(mapping, pos, len, copied, folio);
3029	}
3030
3031	/*
3032	* Force all delayed allocation blocks to be allocated for a given inode.
3033	*/
3034	int ext4_alloc_da_blocks(struct inode *inode)
3035	{
3036	trace_ext4_alloc_da_blocks(inode);
3037
3038	if (!EXT4_I(inode)->i_reserved_data_blocks)
3039	return 0;
3040
3041	/*
3042	* We do something simple for now. The filemap_flush() will
3043	* also start triggering a write of the data blocks, which is
3044	* not strictly speaking necessary (and for users of
3045	* laptop_mode, not even desirable). However, to do otherwise
3046	* would require replicating code paths in:
3047	*
3048	* ext4_writepages() ->
3049	* write_cache_pages() ---> (via passed in callback function)
3050	* __mpage_da_writepage() -->
3051	* mpage_add_bh_to_extent()
3052	* mpage_da_map_blocks()
3053	*
3054	* The problem is that write_cache_pages(), located in
3055	* mm/page-writeback.c, marks pages clean in preparation for
3056	* doing I/O, which is not desirable if we're not planning on
3057	* doing I/O at all.
3058	*
3059	* We could call write_cache_pages(), and then redirty all of
3060	* the pages by calling redirty_page_for_writepage() but that
3061	* would be ugly in the extreme. So instead we would need to
3062	* replicate parts of the code in the above functions,
3063	* simplifying them because we wouldn't actually intend to
3064	* write out the pages, but rather only collect contiguous
3065	* logical block extents, call the multi-block allocator, and
3066	* then update the buffer heads with the block allocations.
3067	*
3068	* For now, though, we'll cheat by calling filemap_flush(),
3069	* which will map the blocks, and start the I/O, but not
3070	* actually wait for the I/O to complete.
3071	*/
3072	return filemap_flush(inode->i_mapping);
3073	}
3074
3075	/*
3076	* bmap() is special. It gets used by applications such as lilo and by
3077	* the swapper to find the on-disk block of a specific piece of data.
3078	*
3079	* Naturally, this is dangerous if the block concerned is still in the
3080	* journal. If somebody makes a swapfile on an ext4 data-journaling
3081	* filesystem and enables swap, then they may get a nasty shock when the
3082	* data getting swapped to that swapfile suddenly gets overwritten by
3083	* the original zero's written out previously to the journal and
3084	* awaiting writeback in the kernel's buffer cache.
3085	*
3086	* So, if we see any bmap calls here on a modified, data-journaled file,
3087	* take extra steps to flush any blocks which might be in the cache.
3088	*/
3089	static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
3090	{
3091	struct inode *inode = mapping->host;
3092	sector_t ret = 0;
3093
3094	inode_lock_shared(inode);
3095	/*
3096	* We can get here for an inline file via the FIBMAP ioctl
3097	*/
3098	if (ext4_has_inline_data(inode))
3099	goto out;
3100
3101	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
3102	(test_opt(inode->i_sb, DELALLOC) ||
3103	ext4_should_journal_data(inode))) {
3104	/*
3105	* With delalloc or journalled data we want to sync the file so
3106	* that we can make sure we allocate blocks for file and data
3107	* is in place for the user to see it
3108	*/
3109	filemap_write_and_wait(mapping);
3110	}
3111
3112	ret = iomap_bmap(mapping, bno: block, ops: &ext4_iomap_ops);
3113
3114	out:
3115	inode_unlock_shared(inode);
3116	return ret;
3117	}
3118
3119	static int ext4_read_folio(struct file *file, struct folio *folio)
3120	{
3121	int ret = -EAGAIN;
3122	struct inode *inode = folio->mapping->host;
3123
3124	trace_ext4_read_folio(inode, folio);
3125
3126	if (ext4_has_inline_data(inode))
3127	ret = ext4_readpage_inline(inode, folio);
3128
3129	if (ret == -EAGAIN)
3130	return ext4_mpage_readpages(inode, NULL, folio);
3131
3132	return ret;
3133	}
3134
3135	static void ext4_readahead(struct readahead_control *rac)
3136	{
3137	struct inode *inode = rac->mapping->host;
3138
3139	/* If the file has inline data, no need to do readahead. */
3140	if (ext4_has_inline_data(inode))
3141	return;
3142
3143	ext4_mpage_readpages(inode, rac, NULL);
3144	}
3145
3146	static void ext4_invalidate_folio(struct folio *folio, size_t offset,
3147	size_t length)
3148	{
3149	trace_ext4_invalidate_folio(folio, offset, length);
3150
3151	/* No journalling happens on data buffers when this function is used */
3152	WARN_ON(folio_buffers(folio) && buffer_jbd(folio_buffers(folio)));
3153
3154	block_invalidate_folio(folio, offset, length);
3155	}
3156
3157	static int __ext4_journalled_invalidate_folio(struct folio *folio,
3158	size_t offset, size_t length)
3159	{
3160	journal_t *journal = EXT4_JOURNAL(folio->mapping->host);
3161
3162	trace_ext4_journalled_invalidate_folio(folio, offset, length);
3163
3164	/*
3165	* If it's a full truncate we just forget about the pending dirtying
3166	*/
3167	if (offset == 0 && length == folio_size(folio))
3168	folio_clear_checked(folio);
3169
3170	return jbd2_journal_invalidate_folio(journal, folio, offset, length);
3171	}
3172
3173	/* Wrapper for aops... */
3174	static void ext4_journalled_invalidate_folio(struct folio *folio,
3175	size_t offset,
3176	size_t length)
3177	{
3178	WARN_ON(__ext4_journalled_invalidate_folio(folio, offset, length) < 0);
3179	}
3180
3181	static bool ext4_release_folio(struct folio *folio, gfp_t wait)
3182	{
3183	struct inode *inode = folio->mapping->host;
3184	journal_t *journal = EXT4_JOURNAL(inode);
3185
3186	trace_ext4_release_folio(inode, folio);
3187
3188	/* Page has dirty journalled data -> cannot release */
3189	if (folio_test_checked(folio))
3190	return false;
3191	if (journal)
3192	return jbd2_journal_try_to_free_buffers(journal, folio);
3193	else
3194	return try_to_free_buffers(folio);
3195	}
3196
3197	static bool ext4_inode_datasync_dirty(struct inode *inode)
3198	{
3199	journal_t *journal = EXT4_SB(sb: inode->i_sb)->s_journal;
3200
3201	if (journal) {
3202	if (jbd2_transaction_committed(journal,
3203	EXT4_I(inode)->i_datasync_tid))
3204	return false;
3205	if (test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT))
3206	return !list_empty(head: &EXT4_I(inode)->i_fc_list);
3207	return true;
3208	}
3209
3210	/* Any metadata buffers to write? */
3211	if (!list_empty(head: &inode->i_mapping->i_private_list))
3212	return true;
3213	return inode->i_state & I_DIRTY_DATASYNC;
3214	}
3215
3216	static void ext4_set_iomap(struct inode *inode, struct iomap *iomap,
3217	struct ext4_map_blocks *map, loff_t offset,
3218	loff_t length, unsigned int flags)
3219	{
3220	u8 blkbits = inode->i_blkbits;
3221
3222	/*
3223	* Writes that span EOF might trigger an I/O size update on completion,
3224	* so consider them to be dirty for the purpose of O_DSYNC, even if
3225	* there is no other metadata changes being made or are pending.
3226	*/
3227	iomap->flags = 0;
3228	if (ext4_inode_datasync_dirty(inode) ||
3229	offset + length > i_size_read(inode))
3230	iomap->flags |= IOMAP_F_DIRTY;
3231
3232	if (map->m_flags & EXT4_MAP_NEW)
3233	iomap->flags |= IOMAP_F_NEW;
3234
3235	if (flags & IOMAP_DAX)
3236	iomap->dax_dev = EXT4_SB(sb: inode->i_sb)->s_daxdev;
3237	else
3238	iomap->bdev = inode->i_sb->s_bdev;
3239	iomap->offset = (u64) map->m_lblk << blkbits;
3240	iomap->length = (u64) map->m_len << blkbits;
3241
3242	if ((map->m_flags & EXT4_MAP_MAPPED) &&
3243	!ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))
3244	iomap->flags |= IOMAP_F_MERGED;
3245
3246	/*
3247	* Flags passed to ext4_map_blocks() for direct I/O writes can result
3248	* in m_flags having both EXT4_MAP_MAPPED and EXT4_MAP_UNWRITTEN bits
3249	* set. In order for any allocated unwritten extents to be converted
3250	* into written extents correctly within the ->end_io() handler, we
3251	* need to ensure that the iomap->type is set appropriately. Hence, the
3252	* reason why we need to check whether the EXT4_MAP_UNWRITTEN bit has
3253	* been set first.
3254	*/
3255	if (map->m_flags & EXT4_MAP_UNWRITTEN) {
3256	iomap->type = IOMAP_UNWRITTEN;
3257	iomap->addr = (u64) map->m_pblk << blkbits;
3258	if (flags & IOMAP_DAX)
3259	iomap->addr += EXT4_SB(sb: inode->i_sb)->s_dax_part_off;
3260	} else if (map->m_flags & EXT4_MAP_MAPPED) {
3261	iomap->type = IOMAP_MAPPED;
3262	iomap->addr = (u64) map->m_pblk << blkbits;
3263	if (flags & IOMAP_DAX)
3264	iomap->addr += EXT4_SB(sb: inode->i_sb)->s_dax_part_off;
3265	} else if (map->m_flags & EXT4_MAP_DELAYED) {
3266	iomap->type = IOMAP_DELALLOC;
3267	iomap->addr = IOMAP_NULL_ADDR;
3268	} else {
3269	iomap->type = IOMAP_HOLE;
3270	iomap->addr = IOMAP_NULL_ADDR;
3271	}
3272	}
3273
3274	static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map,
3275	unsigned int flags)
3276	{
3277	handle_t *handle;
3278	u8 blkbits = inode->i_blkbits;
3279	int ret, dio_credits, m_flags = 0, retries = 0;
3280
3281	/*
3282	* Trim the mapping request to the maximum value that we can map at
3283	* once for direct I/O.
3284	*/
3285	if (map->m_len > DIO_MAX_BLOCKS)
3286	map->m_len = DIO_MAX_BLOCKS;
3287	dio_credits = ext4_chunk_trans_blocks(inode, nrblocks: map->m_len);
3288
3289	retry:
3290	/*
3291	* Either we allocate blocks and then don't get an unwritten extent, so
3292	* in that case we have reserved enough credits. Or, the blocks are
3293	* already allocated and unwritten. In that case, the extent conversion
3294	* fits into the credits as well.
3295	*/
3296	handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
3297	if (IS_ERR(ptr: handle))
3298	return PTR_ERR(ptr: handle);
3299
3300	/*
3301	* DAX and direct I/O are the only two operations that are currently
3302	* supported with IOMAP_WRITE.
3303	*/
3304	WARN_ON(!(flags & (IOMAP_DAX | IOMAP_DIRECT)));
3305	if (flags & IOMAP_DAX)
3306	m_flags = EXT4_GET_BLOCKS_CREATE_ZERO;
3307	/*
3308	* We use i_size instead of i_disksize here because delalloc writeback
3309	* can complete at any point during the I/O and subsequently push the
3310	* i_disksize out to i_size. This could be beyond where direct I/O is
3311	* happening and thus expose allocated blocks to direct I/O reads.
3312	*/
3313	else if (((loff_t)map->m_lblk << blkbits) >= i_size_read(inode))
3314	m_flags = EXT4_GET_BLOCKS_CREATE;
3315	else if (ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))
3316	m_flags = EXT4_GET_BLOCKS_IO_CREATE_EXT;
3317
3318	ret = ext4_map_blocks(handle, inode, map, flags: m_flags);
3319
3320	/*
3321	* We cannot fill holes in indirect tree based inodes as that could
3322	* expose stale data in the case of a crash. Use the magic error code
3323	* to fallback to buffered I/O.
3324	*/
3325	if (!m_flags && !ret)
3326	ret = -ENOTBLK;
3327
3328	ext4_journal_stop(handle);
3329	if (ret == -ENOSPC && ext4_should_retry_alloc(sb: inode->i_sb, retries: &retries))
3330	goto retry;
3331
3332	return ret;
3333	}
3334
3335
3336	static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
3337	unsigned flags, struct iomap *iomap, struct iomap *srcmap)
3338	{
3339	int ret;
3340	struct ext4_map_blocks map;
3341	u8 blkbits = inode->i_blkbits;
3342
3343	if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK)
3344	return -EINVAL;
3345
3346	if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
3347	return -ERANGE;
3348
3349	/*
3350	* Calculate the first and last logical blocks respectively.
3351	*/
3352	map.m_lblk = offset >> blkbits;
3353	map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits,
3354	EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1;
3355
3356	if (flags & IOMAP_WRITE) {
3357	/*
3358	* We check here if the blocks are already allocated, then we
3359	* don't need to start a journal txn and we can directly return
3360	* the mapping information. This could boost performance
3361	* especially in multi-threaded overwrite requests.
3362	*/
3363	if (offset + length <= i_size_read(inode)) {
3364	ret = ext4_map_blocks(NULL, inode, map: &map, flags: 0);
3365	if (ret > 0 && (map.m_flags & EXT4_MAP_MAPPED))
3366	goto out;
3367	}
3368	ret = ext4_iomap_alloc(inode, map: &map, flags);
3369	} else {
3370	ret = ext4_map_blocks(NULL, inode, map: &map, flags: 0);
3371	}
3372
3373	if (ret < 0)
3374	return ret;
3375	out:
3376	/*
3377	* When inline encryption is enabled, sometimes I/O to an encrypted file
3378	* has to be broken up to guarantee DUN contiguity. Handle this by
3379	* limiting the length of the mapping returned.
3380	*/
3381	map.m_len = fscrypt_limit_io_blocks(inode, lblk: map.m_lblk, nr_blocks: map.m_len);
3382
3383	ext4_set_iomap(inode, iomap, map: &map, offset, length, flags);
3384
3385	return 0;
3386	}
3387
3388	static int ext4_iomap_overwrite_begin(struct inode *inode, loff_t offset,
3389	loff_t length, unsigned flags, struct iomap *iomap,
3390	struct iomap *srcmap)
3391	{
3392	int ret;
3393
3394	/*
3395	* Even for writes we don't need to allocate blocks, so just pretend
3396	* we are reading to save overhead of starting a transaction.
3397	*/
3398	flags &= ~IOMAP_WRITE;
3399	ret = ext4_iomap_begin(inode, offset, length, flags, iomap, srcmap);
3400	WARN_ON_ONCE(!ret && iomap->type != IOMAP_MAPPED);
3401	return ret;
3402	}
3403
3404	static int ext4_iomap_end(struct inode *inode, loff_t offset, loff_t length,
3405	ssize_t written, unsigned flags, struct iomap *iomap)
3406	{
3407	/*
3408	* Check to see whether an error occurred while writing out the data to
3409	* the allocated blocks. If so, return the magic error code so that we
3410	* fallback to buffered I/O and attempt to complete the remainder of
3411	* the I/O. Any blocks that may have been allocated in preparation for
3412	* the direct I/O will be reused during buffered I/O.
3413	*/
3414	if (flags & (IOMAP_WRITE | IOMAP_DIRECT) && written == 0)
3415	return -ENOTBLK;
3416
3417	return 0;
3418	}
3419
3420	const struct iomap_ops ext4_iomap_ops = {
3421	.iomap_begin = ext4_iomap_begin,
3422	.iomap_end = ext4_iomap_end,
3423	};
3424
3425	const struct iomap_ops ext4_iomap_overwrite_ops = {
3426	.iomap_begin = ext4_iomap_overwrite_begin,
3427	.iomap_end = ext4_iomap_end,
3428	};
3429
3430	static int ext4_iomap_begin_report(struct inode *inode, loff_t offset,
3431	loff_t length, unsigned int flags,
3432	struct iomap *iomap, struct iomap *srcmap)
3433	{
3434	int ret;
3435	struct ext4_map_blocks map;
3436	u8 blkbits = inode->i_blkbits;
3437
3438	if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK)
3439	return -EINVAL;
3440
3441	if (ext4_has_inline_data(inode)) {
3442	ret = ext4_inline_data_iomap(inode, iomap);
3443	if (ret != -EAGAIN) {
3444	if (ret == 0 && offset >= iomap->length)
3445	ret = -ENOENT;
3446	return ret;
3447	}
3448	}
3449
3450	/*
3451	* Calculate the first and last logical block respectively.
3452	*/
3453	map.m_lblk = offset >> blkbits;
3454	map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits,
3455	EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1;
3456
3457	/*
3458	* Fiemap callers may call for offset beyond s_bitmap_maxbytes.
3459	* So handle it here itself instead of querying ext4_map_blocks().
3460	* Since ext4_map_blocks() will warn about it and will return
3461	* -EIO error.
3462	*/
3463	if (!(ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))) {
3464	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
3465
3466	if (offset >= sbi->s_bitmap_maxbytes) {
3467	map.m_flags = 0;
3468	goto set_iomap;
3469	}
3470	}
3471
3472	ret = ext4_map_blocks(NULL, inode, map: &map, flags: 0);
3473	if (ret < 0)
3474	return ret;
3475	set_iomap:
3476	ext4_set_iomap(inode, iomap, map: &map, offset, length, flags);
3477
3478	return 0;
3479	}
3480
3481	const struct iomap_ops ext4_iomap_report_ops = {
3482	.iomap_begin = ext4_iomap_begin_report,
3483	};
3484
3485	/*
3486	* For data=journal mode, folio should be marked dirty only when it was
3487	* writeably mapped. When that happens, it was already attached to the
3488	* transaction and marked as jbddirty (we take care of this in
3489	* ext4_page_mkwrite()). On transaction commit, we writeprotect page mappings
3490	* so we should have nothing to do here, except for the case when someone
3491	* had the page pinned and dirtied the page through this pin (e.g. by doing
3492	* direct IO to it). In that case we'd need to attach buffers here to the
3493	* transaction but we cannot due to lock ordering. We cannot just dirty the
3494	* folio and leave attached buffers clean, because the buffers' dirty state is
3495	* "definitive". We cannot just set the buffers dirty or jbddirty because all
3496	* the journalling code will explode. So what we do is to mark the folio
3497	* "pending dirty" and next time ext4_writepages() is called, attach buffers
3498	* to the transaction appropriately.
3499	*/
3500	static bool ext4_journalled_dirty_folio(struct address_space *mapping,
3501	struct folio *folio)
3502	{
3503	WARN_ON_ONCE(!folio_buffers(folio));
3504	if (folio_maybe_dma_pinned(folio))
3505	folio_set_checked(folio);
3506	return filemap_dirty_folio(mapping, folio);
3507	}
3508
3509	static bool ext4_dirty_folio(struct address_space *mapping, struct folio *folio)
3510	{
3511	WARN_ON_ONCE(!folio_test_locked(folio) && !folio_test_dirty(folio));
3512	WARN_ON_ONCE(!folio_buffers(folio));
3513	return block_dirty_folio(mapping, folio);
3514	}
3515
3516	static int ext4_iomap_swap_activate(struct swap_info_struct *sis,
3517	struct file *file, sector_t *span)
3518	{
3519	return iomap_swapfile_activate(sis, swap_file: file, pagespan: span,
3520	ops: &ext4_iomap_report_ops);
3521	}
3522
3523	static const struct address_space_operations ext4_aops = {
3524	.read_folio = ext4_read_folio,
3525	.readahead = ext4_readahead,
3526	.writepages = ext4_writepages,
3527	.write_begin = ext4_write_begin,
3528	.write_end = ext4_write_end,
3529	.dirty_folio = ext4_dirty_folio,
3530	.bmap = ext4_bmap,
3531	.invalidate_folio = ext4_invalidate_folio,
3532	.release_folio = ext4_release_folio,
3533	.direct_IO = noop_direct_IO,
3534	.migrate_folio = buffer_migrate_folio,
3535	.is_partially_uptodate = block_is_partially_uptodate,
3536	.error_remove_folio = generic_error_remove_folio,
3537	.swap_activate = ext4_iomap_swap_activate,
3538	};
3539
3540	static const struct address_space_operations ext4_journalled_aops = {
3541	.read_folio = ext4_read_folio,
3542	.readahead = ext4_readahead,
3543	.writepages = ext4_writepages,
3544	.write_begin = ext4_write_begin,
3545	.write_end = ext4_journalled_write_end,
3546	.dirty_folio = ext4_journalled_dirty_folio,
3547	.bmap = ext4_bmap,
3548	.invalidate_folio = ext4_journalled_invalidate_folio,
3549	.release_folio = ext4_release_folio,
3550	.direct_IO = noop_direct_IO,
3551	.migrate_folio = buffer_migrate_folio_norefs,
3552	.is_partially_uptodate = block_is_partially_uptodate,
3553	.error_remove_folio = generic_error_remove_folio,
3554	.swap_activate = ext4_iomap_swap_activate,
3555	};
3556
3557	static const struct address_space_operations ext4_da_aops = {
3558	.read_folio = ext4_read_folio,
3559	.readahead = ext4_readahead,
3560	.writepages = ext4_writepages,
3561	.write_begin = ext4_da_write_begin,
3562	.write_end = ext4_da_write_end,
3563	.dirty_folio = ext4_dirty_folio,
3564	.bmap = ext4_bmap,
3565	.invalidate_folio = ext4_invalidate_folio,
3566	.release_folio = ext4_release_folio,
3567	.direct_IO = noop_direct_IO,
3568	.migrate_folio = buffer_migrate_folio,
3569	.is_partially_uptodate = block_is_partially_uptodate,
3570	.error_remove_folio = generic_error_remove_folio,
3571	.swap_activate = ext4_iomap_swap_activate,
3572	};
3573
3574	static const struct address_space_operations ext4_dax_aops = {
3575	.writepages = ext4_dax_writepages,
3576	.direct_IO = noop_direct_IO,
3577	.dirty_folio = noop_dirty_folio,
3578	.bmap = ext4_bmap,
3579	.swap_activate = ext4_iomap_swap_activate,
3580	};
3581
3582	void ext4_set_aops(struct inode *inode)
3583	{
3584	switch (ext4_inode_journal_mode(inode)) {
3585	case EXT4_INODE_ORDERED_DATA_MODE:
3586	case EXT4_INODE_WRITEBACK_DATA_MODE:
3587	break;
3588	case EXT4_INODE_JOURNAL_DATA_MODE:
3589	inode->i_mapping->a_ops = &ext4_journalled_aops;
3590	return;
3591	default:
3592	BUG();
3593	}
3594	if (IS_DAX(inode))
3595	inode->i_mapping->a_ops = &ext4_dax_aops;
3596	else if (test_opt(inode->i_sb, DELALLOC))
3597	inode->i_mapping->a_ops = &ext4_da_aops;
3598	else
3599	inode->i_mapping->a_ops = &ext4_aops;
3600	}
3601
3602	/*
3603	* Here we can't skip an unwritten buffer even though it usually reads zero
3604	* because it might have data in pagecache (eg, if called from ext4_zero_range,
3605	* ext4_punch_hole, etc) which needs to be properly zeroed out. Otherwise a
3606	* racing writeback can come later and flush the stale pagecache to disk.
3607	*/
3608	static int __ext4_block_zero_page_range(handle_t *handle,
3609	struct address_space *mapping, loff_t from, loff_t length)
3610	{
3611	ext4_fsblk_t index = from >> PAGE_SHIFT;
3612	unsigned offset = from & (PAGE_SIZE-1);
3613	unsigned blocksize, pos;
3614	ext4_lblk_t iblock;
3615	struct inode *inode = mapping->host;
3616	struct buffer_head *bh;
3617	struct folio *folio;
3618	int err = 0;
3619
3620	folio = __filemap_get_folio(mapping, index: from >> PAGE_SHIFT,
3621	FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
3622	gfp: mapping_gfp_constraint(mapping, gfp_mask: ~__GFP_FS));
3623	if (IS_ERR(ptr: folio))
3624	return PTR_ERR(ptr: folio);
3625
3626	blocksize = inode->i_sb->s_blocksize;
3627
3628	iblock = index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
3629
3630	bh = folio_buffers(folio);
3631	if (!bh)
3632	bh = create_empty_buffers(folio, blocksize, b_state: 0);
3633
3634	/* Find the buffer that contains "offset" */
3635	pos = blocksize;
3636	while (offset >= pos) {
3637	bh = bh->b_this_page;
3638	iblock++;
3639	pos += blocksize;
3640	}
3641	if (buffer_freed(bh)) {
3642	BUFFER_TRACE(bh, "freed: skip");
3643	goto unlock;
3644	}
3645	if (!buffer_mapped(bh)) {
3646	BUFFER_TRACE(bh, "unmapped");
3647	ext4_get_block(inode, iblock, bh, create: 0);
3648	/* unmapped? It's a hole - nothing to do */
3649	if (!buffer_mapped(bh)) {
3650	BUFFER_TRACE(bh, "still unmapped");
3651	goto unlock;
3652	}
3653	}
3654
3655	/* Ok, it's mapped. Make sure it's up-to-date */
3656	if (folio_test_uptodate(folio))
3657	set_buffer_uptodate(bh);
3658
3659	if (!buffer_uptodate(bh)) {
3660	err = ext4_read_bh_lock(bh, op_flags: 0, wait: true);
3661	if (err)
3662	goto unlock;
3663	if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
3664	/* We expect the key to be set. */
3665	BUG_ON(!fscrypt_has_encryption_key(inode));
3666	err = fscrypt_decrypt_pagecache_blocks(folio,
3667	len: blocksize,
3668	offs: bh_offset(bh));
3669	if (err) {
3670	clear_buffer_uptodate(bh);
3671	goto unlock;
3672	}
3673	}
3674	}
3675	if (ext4_should_journal_data(inode)) {
3676	BUFFER_TRACE(bh, "get write access");
3677	err = ext4_journal_get_write_access(handle, inode->i_sb, bh,
3678	EXT4_JTR_NONE);
3679	if (err)
3680	goto unlock;
3681	}
3682	folio_zero_range(folio, start: offset, length);
3683	BUFFER_TRACE(bh, "zeroed end of block");
3684
3685	if (ext4_should_journal_data(inode)) {
3686	err = ext4_dirty_journalled_data(handle, bh);
3687	} else {
3688	err = 0;
3689	mark_buffer_dirty(bh);
3690	if (ext4_should_order_data(inode))
3691	err = ext4_jbd2_inode_add_write(handle, inode, start_byte: from,
3692	length);
3693	}
3694
3695	unlock:
3696	folio_unlock(folio);
3697	folio_put(folio);
3698	return err;
3699	}
3700
3701	/*
3702	* ext4_block_zero_page_range() zeros out a mapping of length 'length'
3703	* starting from file offset 'from'. The range to be zero'd must
3704	* be contained with in one block. If the specified range exceeds
3705	* the end of the block it will be shortened to end of the block
3706	* that corresponds to 'from'
3707	*/
3708	static int ext4_block_zero_page_range(handle_t *handle,
3709	struct address_space *mapping, loff_t from, loff_t length)
3710	{
3711	struct inode *inode = mapping->host;
3712	unsigned offset = from & (PAGE_SIZE-1);
3713	unsigned blocksize = inode->i_sb->s_blocksize;
3714	unsigned max = blocksize - (offset & (blocksize - 1));
3715
3716	/*
3717	* correct length if it does not fall between
3718	* 'from' and the end of the block
3719	*/
3720	if (length > max || length < 0)
3721	length = max;
3722
3723	if (IS_DAX(inode)) {
3724	return dax_zero_range(inode, pos: from, len: length, NULL,
3725	ops: &ext4_iomap_ops);
3726	}
3727	return __ext4_block_zero_page_range(handle, mapping, from, length);
3728	}
3729
3730	/*
3731	* ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3732	* up to the end of the block which corresponds to `from'.
3733	* This required during truncate. We need to physically zero the tail end
3734	* of that block so it doesn't yield old data if the file is later grown.
3735	*/
3736	static int ext4_block_truncate_page(handle_t *handle,
3737	struct address_space *mapping, loff_t from)
3738	{
3739	unsigned offset = from & (PAGE_SIZE-1);
3740	unsigned length;
3741	unsigned blocksize;
3742	struct inode *inode = mapping->host;
3743
3744	/* If we are processing an encrypted inode during orphan list handling */
3745	if (IS_ENCRYPTED(inode) && !fscrypt_has_encryption_key(inode))
3746	return 0;
3747
3748	blocksize = inode->i_sb->s_blocksize;
3749	length = blocksize - (offset & (blocksize - 1));
3750
3751	return ext4_block_zero_page_range(handle, mapping, from, length);
3752	}
3753
3754	int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
3755	loff_t lstart, loff_t length)
3756	{
3757	struct super_block *sb = inode->i_sb;
3758	struct address_space *mapping = inode->i_mapping;
3759	unsigned partial_start, partial_end;
3760	ext4_fsblk_t start, end;
3761	loff_t byte_end = (lstart + length - 1);
3762	int err = 0;
3763
3764	partial_start = lstart & (sb->s_blocksize - 1);
3765	partial_end = byte_end & (sb->s_blocksize - 1);
3766
3767	start = lstart >> sb->s_blocksize_bits;
3768	end = byte_end >> sb->s_blocksize_bits;
3769
3770	/* Handle partial zero within the single block */
3771	if (start == end &&
3772	(partial_start || (partial_end != sb->s_blocksize - 1))) {
3773	err = ext4_block_zero_page_range(handle, mapping,
3774	from: lstart, length);
3775	return err;
3776	}
3777	/* Handle partial zero out on the start of the range */
3778	if (partial_start) {
3779	err = ext4_block_zero_page_range(handle, mapping,
3780	from: lstart, length: sb->s_blocksize);
3781	if (err)
3782	return err;
3783	}
3784	/* Handle partial zero out on the end of the range */
3785	if (partial_end != sb->s_blocksize - 1)
3786	err = ext4_block_zero_page_range(handle, mapping,
3787	from: byte_end - partial_end,
3788	length: partial_end + 1);
3789	return err;
3790	}
3791
3792	int ext4_can_truncate(struct inode *inode)
3793	{
3794	if (S_ISREG(inode->i_mode))
3795	return 1;
3796	if (S_ISDIR(inode->i_mode))
3797	return 1;
3798	if (S_ISLNK(inode->i_mode))
3799	return !ext4_inode_is_fast_symlink(inode);
3800	return 0;
3801	}
3802
3803	/*
3804	* We have to make sure i_disksize gets properly updated before we truncate
3805	* page cache due to hole punching or zero range. Otherwise i_disksize update
3806	* can get lost as it may have been postponed to submission of writeback but
3807	* that will never happen after we truncate page cache.
3808	*/
3809	int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
3810	loff_t len)
3811	{
3812	handle_t *handle;
3813	int ret;
3814
3815	loff_t size = i_size_read(inode);
3816
3817	WARN_ON(!inode_is_locked(inode));
3818	if (offset > size || offset + len < size)
3819	return 0;
3820
3821	if (EXT4_I(inode)->i_disksize >= size)
3822	return 0;
3823
3824	handle = ext4_journal_start(inode, EXT4_HT_MISC, 1);
3825	if (IS_ERR(ptr: handle))
3826	return PTR_ERR(ptr: handle);
3827	ext4_update_i_disksize(inode, newsize: size);
3828	ret = ext4_mark_inode_dirty(handle, inode);
3829	ext4_journal_stop(handle);
3830
3831	return ret;
3832	}
3833
3834	static void ext4_wait_dax_page(struct inode *inode)
3835	{
3836	filemap_invalidate_unlock(mapping: inode->i_mapping);
3837	schedule();
3838	filemap_invalidate_lock(mapping: inode->i_mapping);
3839	}
3840
3841	int ext4_break_layouts(struct inode *inode)
3842	{
3843	struct page *page;
3844	int error;
3845
3846	if (WARN_ON_ONCE(!rwsem_is_locked(&inode->i_mapping->invalidate_lock)))
3847	return -EINVAL;
3848
3849	do {
3850	page = dax_layout_busy_page(mapping: inode->i_mapping);
3851	if (!page)
3852	return 0;
3853
3854	error = ___wait_var_event(&page->_refcount,
3855	atomic_read(&page->_refcount) == 1,
3856	TASK_INTERRUPTIBLE, 0, 0,
3857	ext4_wait_dax_page(inode));
3858	} while (error == 0);
3859
3860	return error;
3861	}
3862
3863	/*
3864	* ext4_punch_hole: punches a hole in a file by releasing the blocks
3865	* associated with the given offset and length
3866	*
3867	* @inode: File inode
3868	* @offset: The offset where the hole will begin
3869	* @len: The length of the hole
3870	*
3871	* Returns: 0 on success or negative on failure
3872	*/
3873
3874	int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
3875	{
3876	struct inode *inode = file_inode(f: file);
3877	struct super_block *sb = inode->i_sb;
3878	ext4_lblk_t first_block, stop_block;
3879	struct address_space *mapping = inode->i_mapping;
3880	loff_t first_block_offset, last_block_offset, max_length;
3881	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
3882	handle_t *handle;
3883	unsigned int credits;
3884	int ret = 0, ret2 = 0;
3885
3886	trace_ext4_punch_hole(inode, offset, len: length, mode: 0);
3887
3888	/*
3889	* Write out all dirty pages to avoid race conditions
3890	* Then release them.
3891	*/
3892	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
3893	ret = filemap_write_and_wait_range(mapping, lstart: offset,
3894	lend: offset + length - 1);
3895	if (ret)
3896	return ret;
3897	}
3898
3899	inode_lock(inode);
3900
3901	/* No need to punch hole beyond i_size */
3902	if (offset >= inode->i_size)
3903	goto out_mutex;
3904
3905	/*
3906	* If the hole extends beyond i_size, set the hole
3907	* to end after the page that contains i_size
3908	*/
3909	if (offset + length > inode->i_size) {
3910	length = inode->i_size +
3911	PAGE_SIZE - (inode->i_size & (PAGE_SIZE - 1)) -
3912	offset;
3913	}
3914
3915	/*
3916	* For punch hole the length + offset needs to be within one block
3917	* before last range. Adjust the length if it goes beyond that limit.
3918	*/
3919	max_length = sbi->s_bitmap_maxbytes - inode->i_sb->s_blocksize;
3920	if (offset + length > max_length)
3921	length = max_length - offset;
3922
3923	if (offset & (sb->s_blocksize - 1) ||
3924	(offset + length) & (sb->s_blocksize - 1)) {
3925	/*
3926	* Attach jinode to inode for jbd2 if we do any zeroing of
3927	* partial block
3928	*/
3929	ret = ext4_inode_attach_jinode(inode);
3930	if (ret < 0)
3931	goto out_mutex;
3932
3933	}
3934
3935	/* Wait all existing dio workers, newcomers will block on i_rwsem */
3936	inode_dio_wait(inode);
3937
3938	ret = file_modified(file);
3939	if (ret)
3940	goto out_mutex;
3941
3942	/*
3943	* Prevent page faults from reinstantiating pages we have released from
3944	* page cache.
3945	*/
3946	filemap_invalidate_lock(mapping);
3947
3948	ret = ext4_break_layouts(inode);
3949	if (ret)
3950	goto out_dio;
3951
3952	first_block_offset = round_up(offset, sb->s_blocksize);
3953	last_block_offset = round_down((offset + length), sb->s_blocksize) - 1;
3954
3955	/* Now release the pages and zero block aligned part of pages*/
3956	if (last_block_offset > first_block_offset) {
3957	ret = ext4_update_disksize_before_punch(inode, offset, len: length);
3958	if (ret)
3959	goto out_dio;
3960	truncate_pagecache_range(inode, offset: first_block_offset,
3961	end: last_block_offset);
3962	}
3963
3964	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))
3965	credits = ext4_writepage_trans_blocks(inode);
3966	else
3967	credits = ext4_blocks_for_truncate(inode);
3968	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
3969	if (IS_ERR(ptr: handle)) {
3970	ret = PTR_ERR(ptr: handle);
3971	ext4_std_error(sb, ret);
3972	goto out_dio;
3973	}
3974
3975	ret = ext4_zero_partial_blocks(handle, inode, lstart: offset,
3976	length);
3977	if (ret)
3978	goto out_stop;
3979
3980	first_block = (offset + sb->s_blocksize - 1) >>
3981	EXT4_BLOCK_SIZE_BITS(sb);
3982	stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
3983
3984	/* If there are blocks to remove, do it */
3985	if (stop_block > first_block) {
3986	ext4_lblk_t hole_len = stop_block - first_block;
3987
3988	down_write(sem: &EXT4_I(inode)->i_data_sem);
3989	ext4_discard_preallocations(inode);
3990
3991	ext4_es_remove_extent(inode, lblk: first_block, len: hole_len);
3992
3993	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))
3994	ret = ext4_ext_remove_space(inode, start: first_block,
3995	end: stop_block - 1);
3996	else
3997	ret = ext4_ind_remove_space(handle, inode, start: first_block,
3998	end: stop_block);
3999
4000	ext4_es_insert_extent(inode, lblk: first_block, len: hole_len, pblk: ~0,
4001	EXTENT_STATUS_HOLE);
4002	up_write(sem: &EXT4_I(inode)->i_data_sem);
4003	}
4004	ext4_fc_track_range(handle, inode, start: first_block, end: stop_block);
4005	if (IS_SYNC(inode))
4006	ext4_handle_sync(handle);
4007
4008	inode_set_mtime_to_ts(inode, ts: inode_set_ctime_current(inode));
4009	ret2 = ext4_mark_inode_dirty(handle, inode);
4010	if (unlikely(ret2))
4011	ret = ret2;
4012	if (ret >= 0)
4013	ext4_update_inode_fsync_trans(handle, inode, datasync: 1);
4014	out_stop:
4015	ext4_journal_stop(handle);
4016	out_dio:
4017	filemap_invalidate_unlock(mapping);
4018	out_mutex:
4019	inode_unlock(inode);
4020	return ret;
4021	}
4022
4023	int ext4_inode_attach_jinode(struct inode *inode)
4024	{
4025	struct ext4_inode_info *ei = EXT4_I(inode);
4026	struct jbd2_inode *jinode;
4027
4028	if (ei->jinode || !EXT4_SB(sb: inode->i_sb)->s_journal)
4029	return 0;
4030
4031	jinode = jbd2_alloc_inode(GFP_KERNEL);
4032	spin_lock(lock: &inode->i_lock);
4033	if (!ei->jinode) {
4034	if (!jinode) {
4035	spin_unlock(lock: &inode->i_lock);
4036	return -ENOMEM;
4037	}
4038	ei->jinode = jinode;
4039	jbd2_journal_init_jbd_inode(jinode: ei->jinode, inode);
4040	jinode = NULL;
4041	}
4042	spin_unlock(lock: &inode->i_lock);
4043	if (unlikely(jinode != NULL))
4044	jbd2_free_inode(jinode);
4045	return 0;
4046	}
4047
4048	/*
4049	* ext4_truncate()
4050	*
4051	* We block out ext4_get_block() block instantiations across the entire
4052	* transaction, and VFS/VM ensures that ext4_truncate() cannot run
4053	* simultaneously on behalf of the same inode.
4054	*
4055	* As we work through the truncate and commit bits of it to the journal there
4056	* is one core, guiding principle: the file's tree must always be consistent on
4057	* disk. We must be able to restart the truncate after a crash.
4058	*
4059	* The file's tree may be transiently inconsistent in memory (although it
4060	* probably isn't), but whenever we close off and commit a journal transaction,
4061	* the contents of (the filesystem + the journal) must be consistent and
4062	* restartable. It's pretty simple, really: bottom up, right to left (although
4063	* left-to-right works OK too).
4064	*
4065	* Note that at recovery time, journal replay occurs *before* the restart of
4066	* truncate against the orphan inode list.
4067	*
4068	* The committed inode has the new, desired i_size (which is the same as
4069	* i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
4070	* that this inode's truncate did not complete and it will again call
4071	* ext4_truncate() to have another go. So there will be instantiated blocks
4072	* to the right of the truncation point in a crashed ext4 filesystem. But
4073	* that's fine - as long as they are linked from the inode, the post-crash
4074	* ext4_truncate() run will find them and release them.
4075	*/
4076	int ext4_truncate(struct inode *inode)
4077	{
4078	struct ext4_inode_info *ei = EXT4_I(inode);
4079	unsigned int credits;
4080	int err = 0, err2;
4081	handle_t *handle;
4082	struct address_space *mapping = inode->i_mapping;
4083
4084	/*
4085	* There is a possibility that we're either freeing the inode
4086	* or it's a completely new inode. In those cases we might not
4087	* have i_rwsem locked because it's not necessary.
4088	*/
4089	if (!(inode->i_state & (I_NEW|I_FREEING)))
4090	WARN_ON(!inode_is_locked(inode));
4091	trace_ext4_truncate_enter(inode);
4092
4093	if (!ext4_can_truncate(inode))
4094	goto out_trace;
4095
4096	if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
4097	ext4_set_inode_state(inode, bit: EXT4_STATE_DA_ALLOC_CLOSE);
4098
4099	if (ext4_has_inline_data(inode)) {
4100	int has_inline = 1;
4101
4102	err = ext4_inline_data_truncate(inode, has_inline: &has_inline);
4103	if (err || has_inline)
4104	goto out_trace;
4105	}
4106
4107	/* If we zero-out tail of the page, we have to create jinode for jbd2 */
4108	if (inode->i_size & (inode->i_sb->s_blocksize - 1)) {
4109	err = ext4_inode_attach_jinode(inode);
4110	if (err)
4111	goto out_trace;
4112	}
4113
4114	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))
4115	credits = ext4_writepage_trans_blocks(inode);
4116	else
4117	credits = ext4_blocks_for_truncate(inode);
4118
4119	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
4120	if (IS_ERR(ptr: handle)) {
4121	err = PTR_ERR(ptr: handle);
4122	goto out_trace;
4123	}
4124
4125	if (inode->i_size & (inode->i_sb->s_blocksize - 1))
4126	ext4_block_truncate_page(handle, mapping, from: inode->i_size);
4127
4128	/*
4129	* We add the inode to the orphan list, so that if this
4130	* truncate spans multiple transactions, and we crash, we will
4131	* resume the truncate when the filesystem recovers. It also
4132	* marks the inode dirty, to catch the new size.
4133	*
4134	* Implication: the file must always be in a sane, consistent
4135	* truncatable state while each transaction commits.
4136	*/
4137	err = ext4_orphan_add(handle, inode);
4138	if (err)
4139	goto out_stop;
4140
4141	down_write(sem: &EXT4_I(inode)->i_data_sem);
4142
4143	ext4_discard_preallocations(inode);
4144
4145	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))
4146	err = ext4_ext_truncate(handle, inode);
4147	else
4148	ext4_ind_truncate(handle, inode);
4149
4150	up_write(sem: &ei->i_data_sem);
4151	if (err)
4152	goto out_stop;
4153
4154	if (IS_SYNC(inode))
4155	ext4_handle_sync(handle);
4156
4157	out_stop:
4158	/*
4159	* If this was a simple ftruncate() and the file will remain alive,
4160	* then we need to clear up the orphan record which we created above.
4161	* However, if this was a real unlink then we were called by
4162	* ext4_evict_inode(), and we allow that function to clean up the
4163	* orphan info for us.
4164	*/
4165	if (inode->i_nlink)
4166	ext4_orphan_del(handle, inode);
4167
4168	inode_set_mtime_to_ts(inode, ts: inode_set_ctime_current(inode));
4169	err2 = ext4_mark_inode_dirty(handle, inode);
4170	if (unlikely(err2 && !err))
4171	err = err2;
4172	ext4_journal_stop(handle);
4173
4174	out_trace:
4175	trace_ext4_truncate_exit(inode);
4176	return err;
4177	}
4178
4179	static inline u64 ext4_inode_peek_iversion(const struct inode *inode)
4180	{
4181	if (unlikely(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
4182	return inode_peek_iversion_raw(inode);
4183	else
4184	return inode_peek_iversion(inode);
4185	}
4186
4187	static int ext4_inode_blocks_set(struct ext4_inode *raw_inode,
4188	struct ext4_inode_info *ei)
4189	{
4190	struct inode *inode = &(ei->vfs_inode);
4191	u64 i_blocks = READ_ONCE(inode->i_blocks);
4192	struct super_block *sb = inode->i_sb;
4193
4194	if (i_blocks <= ~0U) {
4195	/*
4196	* i_blocks can be represented in a 32 bit variable
4197	* as multiple of 512 bytes
4198	*/
4199	raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4200	raw_inode->i_blocks_high = 0;
4201	ext4_clear_inode_flag(inode, bit: EXT4_INODE_HUGE_FILE);
4202	return 0;
4203	}
4204
4205	/*
4206	* This should never happen since sb->s_maxbytes should not have
4207	* allowed this, sb->s_maxbytes was set according to the huge_file
4208	* feature in ext4_fill_super().
4209	*/
4210	if (!ext4_has_feature_huge_file(sb))
4211	return -EFSCORRUPTED;
4212
4213	if (i_blocks <= 0xffffffffffffULL) {
4214	/*
4215	* i_blocks can be represented in a 48 bit variable
4216	* as multiple of 512 bytes
4217	*/
4218	raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4219	raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4220	ext4_clear_inode_flag(inode, bit: EXT4_INODE_HUGE_FILE);
4221	} else {
4222	ext4_set_inode_flag(inode, bit: EXT4_INODE_HUGE_FILE);
4223	/* i_block is stored in file system block size */
4224	i_blocks = i_blocks >> (inode->i_blkbits - 9);
4225	raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4226	raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4227	}
4228	return 0;
4229	}
4230
4231	static int ext4_fill_raw_inode(struct inode *inode, struct ext4_inode *raw_inode)
4232	{
4233	struct ext4_inode_info *ei = EXT4_I(inode);
4234	uid_t i_uid;
4235	gid_t i_gid;
4236	projid_t i_projid;
4237	int block;
4238	int err;
4239
4240	err = ext4_inode_blocks_set(raw_inode, ei);
4241
4242	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
4243	i_uid = i_uid_read(inode);
4244	i_gid = i_gid_read(inode);
4245	i_projid = from_kprojid(to: &init_user_ns, projid: ei->i_projid);
4246	if (!(test_opt(inode->i_sb, NO_UID32))) {
4247	raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
4248	raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
4249	/*
4250	* Fix up interoperability with old kernels. Otherwise,
4251	* old inodes get re-used with the upper 16 bits of the
4252	* uid/gid intact.
4253	*/
4254	if (ei->i_dtime && list_empty(head: &ei->i_orphan)) {
4255	raw_inode->i_uid_high = 0;
4256	raw_inode->i_gid_high = 0;
4257	} else {
4258	raw_inode->i_uid_high =
4259	cpu_to_le16(high_16_bits(i_uid));
4260	raw_inode->i_gid_high =
4261	cpu_to_le16(high_16_bits(i_gid));
4262	}
4263	} else {
4264	raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
4265	raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
4266	raw_inode->i_uid_high = 0;
4267	raw_inode->i_gid_high = 0;
4268	}
4269	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
4270
4271	EXT4_INODE_SET_CTIME(inode, raw_inode);
4272	EXT4_INODE_SET_MTIME(inode, raw_inode);
4273	EXT4_INODE_SET_ATIME(inode, raw_inode);
4274	EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4275
4276	raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
4277	raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
4278	if (likely(!test_opt2(inode->i_sb, HURD_COMPAT)))
4279	raw_inode->i_file_acl_high =
4280	cpu_to_le16(ei->i_file_acl >> 32);
4281	raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
4282	ext4_isize_set(raw_inode, i_size: ei->i_disksize);
4283
4284	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4285	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4286	if (old_valid_dev(dev: inode->i_rdev)) {
4287	raw_inode->i_block[0] =
4288	cpu_to_le32(old_encode_dev(inode->i_rdev));
4289	raw_inode->i_block[1] = 0;
4290	} else {
4291	raw_inode->i_block[0] = 0;
4292	raw_inode->i_block[1] =
4293	cpu_to_le32(new_encode_dev(inode->i_rdev));
4294	raw_inode->i_block[2] = 0;
4295	}
4296	} else if (!ext4_has_inline_data(inode)) {
4297	for (block = 0; block < EXT4_N_BLOCKS; block++)
4298	raw_inode->i_block[block] = ei->i_data[block];
4299	}
4300
4301	if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
4302	u64 ivers = ext4_inode_peek_iversion(inode);
4303
4304	raw_inode->i_disk_version = cpu_to_le32(ivers);
4305	if (ei->i_extra_isize) {
4306	if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4307	raw_inode->i_version_hi =
4308	cpu_to_le32(ivers >> 32);
4309	raw_inode->i_extra_isize =
4310	cpu_to_le16(ei->i_extra_isize);
4311	}
4312	}
4313
4314	if (i_projid != EXT4_DEF_PROJID &&
4315	!ext4_has_feature_project(sb: inode->i_sb))
4316	err = err ?: -EFSCORRUPTED;
4317
4318	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
4319	EXT4_FITS_IN_INODE(raw_inode, ei, i_projid))
4320	raw_inode->i_projid = cpu_to_le32(i_projid);
4321
4322	ext4_inode_csum_set(inode, raw: raw_inode, ei);
4323	return err;
4324	}
4325
4326	/*
4327	* ext4_get_inode_loc returns with an extra refcount against the inode's
4328	* underlying buffer_head on success. If we pass 'inode' and it does not
4329	* have in-inode xattr, we have all inode data in memory that is needed
4330	* to recreate the on-disk version of this inode.
4331	*/
4332	static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino,
4333	struct inode *inode, struct ext4_iloc *iloc,
4334	ext4_fsblk_t *ret_block)
4335	{
4336	struct ext4_group_desc *gdp;
4337	struct buffer_head *bh;
4338	ext4_fsblk_t block;
4339	struct blk_plug plug;
4340	int inodes_per_block, inode_offset;
4341
4342	iloc->bh = NULL;
4343	if (ino < EXT4_ROOT_INO ||
4344	ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
4345	return -EFSCORRUPTED;
4346
4347	iloc->block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
4348	gdp = ext4_get_group_desc(sb, block_group: iloc->block_group, NULL);
4349	if (!gdp)
4350	return -EIO;
4351
4352	/*
4353	* Figure out the offset within the block group inode table
4354	*/
4355	inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
4356	inode_offset = ((ino - 1) %
4357	EXT4_INODES_PER_GROUP(sb));
4358	iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
4359
4360	block = ext4_inode_table(sb, bg: gdp);
4361	if ((block <= le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) ||
4362	(block >= ext4_blocks_count(es: EXT4_SB(sb)->s_es))) {
4363	ext4_error(sb, "Invalid inode table block %llu in "
4364	"block_group %u", block, iloc->block_group);
4365	return -EFSCORRUPTED;
4366	}
4367	block += (inode_offset / inodes_per_block);
4368
4369	bh = sb_getblk(sb, block);
4370	if (unlikely(!bh))
4371	return -ENOMEM;
4372	if (ext4_buffer_uptodate(bh))
4373	goto has_buffer;
4374
4375	lock_buffer(bh);
4376	if (ext4_buffer_uptodate(bh)) {
4377	/* Someone brought it uptodate while we waited */
4378	unlock_buffer(bh);
4379	goto has_buffer;
4380	}
4381
4382	/*
4383	* If we have all information of the inode in memory and this
4384	* is the only valid inode in the block, we need not read the
4385	* block.
4386	*/
4387	if (inode && !ext4_test_inode_state(inode, bit: EXT4_STATE_XATTR)) {
4388	struct buffer_head *bitmap_bh;
4389	int i, start;
4390
4391	start = inode_offset & ~(inodes_per_block - 1);
4392
4393	/* Is the inode bitmap in cache? */
4394	bitmap_bh = sb_getblk(sb, block: ext4_inode_bitmap(sb, bg: gdp));
4395	if (unlikely(!bitmap_bh))
4396	goto make_io;
4397
4398	/*
4399	* If the inode bitmap isn't in cache then the
4400	* optimisation may end up performing two reads instead
4401	* of one, so skip it.
4402	*/
4403	if (!buffer_uptodate(bh: bitmap_bh)) {
4404	brelse(bh: bitmap_bh);
4405	goto make_io;
4406	}
4407	for (i = start; i < start + inodes_per_block; i++) {
4408	if (i == inode_offset)
4409	continue;
4410	if (ext4_test_bit(nr: i, addr: bitmap_bh->b_data))
4411	break;
4412	}
4413	brelse(bh: bitmap_bh);
4414	if (i == start + inodes_per_block) {
4415	struct ext4_inode *raw_inode =
4416	(struct ext4_inode *) (bh->b_data + iloc->offset);
4417
4418	/* all other inodes are free, so skip I/O */
4419	memset(bh->b_data, 0, bh->b_size);
4420	if (!ext4_test_inode_state(inode, bit: EXT4_STATE_NEW))
4421	ext4_fill_raw_inode(inode, raw_inode);
4422	set_buffer_uptodate(bh);
4423	unlock_buffer(bh);
4424	goto has_buffer;
4425	}
4426	}
4427
4428	make_io:
4429	/*
4430	* If we need to do any I/O, try to pre-readahead extra
4431	* blocks from the inode table.
4432	*/
4433	blk_start_plug(&plug);
4434	if (EXT4_SB(sb)->s_inode_readahead_blks) {
4435	ext4_fsblk_t b, end, table;
4436	unsigned num;
4437	__u32 ra_blks = EXT4_SB(sb)->s_inode_readahead_blks;
4438
4439	table = ext4_inode_table(sb, bg: gdp);
4440	/* s_inode_readahead_blks is always a power of 2 */
4441	b = block & ~((ext4_fsblk_t) ra_blks - 1);
4442	if (table > b)
4443	b = table;
4444	end = b + ra_blks;
4445	num = EXT4_INODES_PER_GROUP(sb);
4446	if (ext4_has_group_desc_csum(sb))
4447	num -= ext4_itable_unused_count(sb, bg: gdp);
4448	table += num / inodes_per_block;
4449	if (end > table)
4450	end = table;
4451	while (b <= end)
4452	ext4_sb_breadahead_unmovable(sb, block: b++);
4453	}
4454
4455	/*
4456	* There are other valid inodes in the buffer, this inode
4457	* has in-inode xattrs, or we don't have this inode in memory.
4458	* Read the block from disk.
4459	*/
4460	trace_ext4_load_inode(sb, ino);
4461	ext4_read_bh_nowait(bh, REQ_META | REQ_PRIO, NULL);
4462	blk_finish_plug(&plug);
4463	wait_on_buffer(bh);
4464	ext4_simulate_fail_bh(sb, bh, EXT4_SIM_INODE_EIO);
4465	if (!buffer_uptodate(bh)) {
4466	if (ret_block)
4467	*ret_block = block;
4468	brelse(bh);
4469	return -EIO;
4470	}
4471	has_buffer:
4472	iloc->bh = bh;
4473	return 0;
4474	}
4475
4476	static int __ext4_get_inode_loc_noinmem(struct inode *inode,
4477	struct ext4_iloc *iloc)
4478	{
4479	ext4_fsblk_t err_blk = 0;
4480	int ret;
4481
4482	ret = __ext4_get_inode_loc(sb: inode->i_sb, ino: inode->i_ino, NULL, iloc,
4483	ret_block: &err_blk);
4484
4485	if (ret == -EIO)
4486	ext4_error_inode_block(inode, err_blk, EIO,
4487	"unable to read itable block");
4488
4489	return ret;
4490	}
4491
4492	int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
4493	{
4494	ext4_fsblk_t err_blk = 0;
4495	int ret;
4496
4497	ret = __ext4_get_inode_loc(sb: inode->i_sb, ino: inode->i_ino, inode, iloc,
4498	ret_block: &err_blk);
4499
4500	if (ret == -EIO)
4501	ext4_error_inode_block(inode, err_blk, EIO,
4502	"unable to read itable block");
4503
4504	return ret;
4505	}
4506
4507
4508	int ext4_get_fc_inode_loc(struct super_block *sb, unsigned long ino,
4509	struct ext4_iloc *iloc)
4510	{
4511	return __ext4_get_inode_loc(sb, ino, NULL, iloc, NULL);
4512	}
4513
4514	static bool ext4_should_enable_dax(struct inode *inode)
4515	{
4516	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
4517
4518	if (test_opt2(inode->i_sb, DAX_NEVER))
4519	return false;
4520	if (!S_ISREG(inode->i_mode))
4521	return false;
4522	if (ext4_should_journal_data(inode))
4523	return false;
4524	if (ext4_has_inline_data(inode))
4525	return false;
4526	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_ENCRYPT))
4527	return false;
4528	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_VERITY))
4529	return false;
4530	if (!test_bit(EXT4_FLAGS_BDEV_IS_DAX, &sbi->s_ext4_flags))
4531	return false;
4532	if (test_opt(inode->i_sb, DAX_ALWAYS))
4533	return true;
4534
4535	return ext4_test_inode_flag(inode, bit: EXT4_INODE_DAX);
4536	}
4537
4538	void ext4_set_inode_flags(struct inode *inode, bool init)
4539	{
4540	unsigned int flags = EXT4_I(inode)->i_flags;
4541	unsigned int new_fl = 0;
4542
4543	WARN_ON_ONCE(IS_DAX(inode) && init);
4544
4545	if (flags & EXT4_SYNC_FL)
4546	new_fl |= S_SYNC;
4547	if (flags & EXT4_APPEND_FL)
4548	new_fl |= S_APPEND;
4549	if (flags & EXT4_IMMUTABLE_FL)
4550	new_fl |= S_IMMUTABLE;
4551	if (flags & EXT4_NOATIME_FL)
4552	new_fl |= S_NOATIME;
4553	if (flags & EXT4_DIRSYNC_FL)
4554	new_fl |= S_DIRSYNC;
4555
4556	/* Because of the way inode_set_flags() works we must preserve S_DAX
4557	* here if already set. */
4558	new_fl |= (inode->i_flags & S_DAX);
4559	if (init && ext4_should_enable_dax(inode))
4560	new_fl |= S_DAX;
4561
4562	if (flags & EXT4_ENCRYPT_FL)
4563	new_fl |= S_ENCRYPTED;
4564	if (flags & EXT4_CASEFOLD_FL)
4565	new_fl |= S_CASEFOLD;
4566	if (flags & EXT4_VERITY_FL)
4567	new_fl |= S_VERITY;
4568	inode_set_flags(inode, flags: new_fl,
4569	S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX|
4570	S_ENCRYPTED|S_CASEFOLD|S_VERITY);
4571	}
4572
4573	static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
4574	struct ext4_inode_info *ei)
4575	{
4576	blkcnt_t i_blocks ;
4577	struct inode *inode = &(ei->vfs_inode);
4578	struct super_block *sb = inode->i_sb;
4579
4580	if (ext4_has_feature_huge_file(sb)) {
4581	/* we are using combined 48 bit field */
4582	i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
4583	le32_to_cpu(raw_inode->i_blocks_lo);
4584	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_HUGE_FILE)) {
4585	/* i_blocks represent file system block size */
4586	return i_blocks << (inode->i_blkbits - 9);
4587	} else {
4588	return i_blocks;
4589	}
4590	} else {
4591	return le32_to_cpu(raw_inode->i_blocks_lo);
4592	}
4593	}
4594
4595	static inline int ext4_iget_extra_inode(struct inode *inode,
4596	struct ext4_inode *raw_inode,
4597	struct ext4_inode_info *ei)
4598	{
4599	__le32 *magic = (void *)raw_inode +
4600	EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize;
4601
4602	if (EXT4_INODE_HAS_XATTR_SPACE(inode) &&
4603	*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
4604	int err;
4605
4606	ext4_set_inode_state(inode, bit: EXT4_STATE_XATTR);
4607	err = ext4_find_inline_data_nolock(inode);
4608	if (!err && ext4_has_inline_data(inode))
4609	ext4_set_inode_state(inode, bit: EXT4_STATE_MAY_INLINE_DATA);
4610	return err;
4611	} else
4612	EXT4_I(inode)->i_inline_off = 0;
4613	return 0;
4614	}
4615
4616	int ext4_get_projid(struct inode *inode, kprojid_t *projid)
4617	{
4618	if (!ext4_has_feature_project(sb: inode->i_sb))
4619	return -EOPNOTSUPP;
4620	*projid = EXT4_I(inode)->i_projid;
4621	return 0;
4622	}
4623
4624	/*
4625	* ext4 has self-managed i_version for ea inodes, it stores the lower 32bit of
4626	* refcount in i_version, so use raw values if inode has EXT4_EA_INODE_FL flag
4627	* set.
4628	*/
4629	static inline void ext4_inode_set_iversion_queried(struct inode *inode, u64 val)
4630	{
4631	if (unlikely(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
4632	inode_set_iversion_raw(inode, val);
4633	else
4634	inode_set_iversion_queried(inode, val);
4635	}
4636
4637	static const char *check_igot_inode(struct inode *inode, ext4_iget_flags flags)
4638
4639	{
4640	if (flags & EXT4_IGET_EA_INODE) {
4641	if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
4642	return "missing EA_INODE flag";
4643	if (ext4_test_inode_state(inode, bit: EXT4_STATE_XATTR) ||
4644	EXT4_I(inode)->i_file_acl)
4645	return "ea_inode with extended attributes";
4646	} else {
4647	if ((EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL))
4648	return "unexpected EA_INODE flag";
4649	}
4650	if (is_bad_inode(inode) && !(flags & EXT4_IGET_BAD))
4651	return "unexpected bad inode w/o EXT4_IGET_BAD";
4652	return NULL;
4653	}
4654
4655	struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
4656	ext4_iget_flags flags, const char *function,
4657	unsigned int line)
4658	{
4659	struct ext4_iloc iloc;
4660	struct ext4_inode *raw_inode;
4661	struct ext4_inode_info *ei;
4662	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4663	struct inode *inode;
4664	const char *err_str;
4665	journal_t *journal = EXT4_SB(sb)->s_journal;
4666	long ret;
4667	loff_t size;
4668	int block;
4669	uid_t i_uid;
4670	gid_t i_gid;
4671	projid_t i_projid;
4672
4673	if ((!(flags & EXT4_IGET_SPECIAL) &&
4674	((ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO) ||
4675	ino == le32_to_cpu(es->s_usr_quota_inum) ||
4676	ino == le32_to_cpu(es->s_grp_quota_inum) ||
4677	ino == le32_to_cpu(es->s_prj_quota_inum) ||
4678	ino == le32_to_cpu(es->s_orphan_file_inum))) ||
4679	(ino < EXT4_ROOT_INO) ||
4680	(ino > le32_to_cpu(es->s_inodes_count))) {
4681	if (flags & EXT4_IGET_HANDLE)
4682	return ERR_PTR(error: -ESTALE);
4683	__ext4_error(sb, function, line, false, EFSCORRUPTED, 0,
4684	"inode #%lu: comm %s: iget: illegal inode #",
4685	ino, current->comm);
4686	return ERR_PTR(error: -EFSCORRUPTED);
4687	}
4688
4689	inode = iget_locked(sb, ino);
4690	if (!inode)
4691	return ERR_PTR(error: -ENOMEM);
4692	if (!(inode->i_state & I_NEW)) {
4693	if ((err_str = check_igot_inode(inode, flags)) != NULL) {
4694	ext4_error_inode(inode, function, line, 0, err_str);
4695	iput(inode);
4696	return ERR_PTR(error: -EFSCORRUPTED);
4697	}
4698	return inode;
4699	}
4700
4701	ei = EXT4_I(inode);
4702	iloc.bh = NULL;
4703
4704	ret = __ext4_get_inode_loc_noinmem(inode, iloc: &iloc);
4705	if (ret < 0)
4706	goto bad_inode;
4707	raw_inode = ext4_raw_inode(iloc: &iloc);
4708
4709	if ((flags & EXT4_IGET_HANDLE) &&
4710	(raw_inode->i_links_count == 0) && (raw_inode->i_mode == 0)) {
4711	ret = -ESTALE;
4712	goto bad_inode;
4713	}
4714
4715	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4716	ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
4717	if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
4718	EXT4_INODE_SIZE(inode->i_sb) ||
4719	(ei->i_extra_isize & 3)) {
4720	ext4_error_inode(inode, function, line, 0,
4721	"iget: bad extra_isize %u "
4722	"(inode size %u)",
4723	ei->i_extra_isize,
4724	EXT4_INODE_SIZE(inode->i_sb));
4725	ret = -EFSCORRUPTED;
4726	goto bad_inode;
4727	}
4728	} else
4729	ei->i_extra_isize = 0;
4730
4731	/* Precompute checksum seed for inode metadata */
4732	if (ext4_has_metadata_csum(sb)) {
4733	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
4734	__u32 csum;
4735	__le32 inum = cpu_to_le32(inode->i_ino);
4736	__le32 gen = raw_inode->i_generation;
4737	csum = ext4_chksum(sbi, crc: sbi->s_csum_seed, address: (__u8 *)&inum,
4738	length: sizeof(inum));
4739	ei->i_csum_seed = ext4_chksum(sbi, crc: csum, address: (__u8 *)&gen,
4740	length: sizeof(gen));
4741	}
4742
4743	if ((!ext4_inode_csum_verify(inode, raw: raw_inode, ei) ||
4744	ext4_simulate_fail(sb, EXT4_SIM_INODE_CRC)) &&
4745	(!(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))) {
4746	ext4_error_inode_err(inode, function, line, 0,
4747	EFSBADCRC, "iget: checksum invalid");
4748	ret = -EFSBADCRC;
4749	goto bad_inode;
4750	}
4751
4752	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
4753	i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
4754	i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
4755	if (ext4_has_feature_project(sb) &&
4756	EXT4_INODE_SIZE(sb) > EXT4_GOOD_OLD_INODE_SIZE &&
4757	EXT4_FITS_IN_INODE(raw_inode, ei, i_projid))
4758	i_projid = (projid_t)le32_to_cpu(raw_inode->i_projid);
4759	else
4760	i_projid = EXT4_DEF_PROJID;
4761
4762	if (!(test_opt(inode->i_sb, NO_UID32))) {
4763	i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
4764	i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
4765	}
4766	i_uid_write(inode, uid: i_uid);
4767	i_gid_write(inode, gid: i_gid);
4768	ei->i_projid = make_kprojid(from: &init_user_ns, projid: i_projid);
4769	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
4770
4771	ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
4772	ei->i_inline_off = 0;
4773	ei->i_dir_start_lookup = 0;
4774	ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
4775	/* We now have enough fields to check if the inode was active or not.
4776	* This is needed because nfsd might try to access dead inodes
4777	* the test is that same one that e2fsck uses
4778	* NeilBrown 1999oct15
4779	*/
4780	if (inode->i_nlink == 0) {
4781	if ((inode->i_mode == 0 || flags & EXT4_IGET_SPECIAL ||
4782	!(EXT4_SB(sb: inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) &&
4783	ino != EXT4_BOOT_LOADER_INO) {
4784	/* this inode is deleted or unallocated */
4785	if (flags & EXT4_IGET_SPECIAL) {
4786	ext4_error_inode(inode, function, line, 0,
4787	"iget: special inode unallocated");
4788	ret = -EFSCORRUPTED;
4789	} else
4790	ret = -ESTALE;
4791	goto bad_inode;
4792	}
4793	/* The only unlinked inodes we let through here have
4794	* valid i_mode and are being read by the orphan
4795	* recovery code: that's fine, we're about to complete
4796	* the process of deleting those.
4797	* OR it is the EXT4_BOOT_LOADER_INO which is
4798	* not initialized on a new filesystem. */
4799	}
4800	ei->i_flags = le32_to_cpu(raw_inode->i_flags);
4801	ext4_set_inode_flags(inode, init: true);
4802	inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
4803	ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
4804	if (ext4_has_feature_64bit(sb))
4805	ei->i_file_acl |=
4806	((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
4807	inode->i_size = ext4_isize(sb, raw_inode);
4808	if ((size = i_size_read(inode)) < 0) {
4809	ext4_error_inode(inode, function, line, 0,
4810	"iget: bad i_size value: %lld", size);
4811	ret = -EFSCORRUPTED;
4812	goto bad_inode;
4813	}
4814	/*
4815	* If dir_index is not enabled but there's dir with INDEX flag set,
4816	* we'd normally treat htree data as empty space. But with metadata
4817	* checksumming that corrupts checksums so forbid that.
4818	*/
4819	if (!ext4_has_feature_dir_index(sb) && ext4_has_metadata_csum(sb) &&
4820	ext4_test_inode_flag(inode, bit: EXT4_INODE_INDEX)) {
4821	ext4_error_inode(inode, function, line, 0,
4822	"iget: Dir with htree data on filesystem without dir_index feature.");
4823	ret = -EFSCORRUPTED;
4824	goto bad_inode;
4825	}
4826	ei->i_disksize = inode->i_size;
4827	#ifdef CONFIG_QUOTA
4828	ei->i_reserved_quota = 0;
4829	#endif
4830	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
4831	ei->i_block_group = iloc.block_group;
4832	ei->i_last_alloc_group = ~0;
4833	/*
4834	* NOTE! The in-memory inode i_data array is in little-endian order
4835	* even on big-endian machines: we do NOT byteswap the block numbers!
4836	*/
4837	for (block = 0; block < EXT4_N_BLOCKS; block++)
4838	ei->i_data[block] = raw_inode->i_block[block];
4839	INIT_LIST_HEAD(list: &ei->i_orphan);
4840	ext4_fc_init_inode(inode: &ei->vfs_inode);
4841
4842	/*
4843	* Set transaction id's of transactions that have to be committed
4844	* to finish f[data]sync. We set them to currently running transaction
4845	* as we cannot be sure that the inode or some of its metadata isn't
4846	* part of the transaction - the inode could have been reclaimed and
4847	* now it is reread from disk.
4848	*/
4849	if (journal) {
4850	transaction_t *transaction;
4851	tid_t tid;
4852
4853	read_lock(&journal->j_state_lock);
4854	if (journal->j_running_transaction)
4855	transaction = journal->j_running_transaction;
4856	else
4857	transaction = journal->j_committing_transaction;
4858	if (transaction)
4859	tid = transaction->t_tid;
4860	else
4861	tid = journal->j_commit_sequence;
4862	read_unlock(&journal->j_state_lock);
4863	ei->i_sync_tid = tid;
4864	ei->i_datasync_tid = tid;
4865	}
4866
4867	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4868	if (ei->i_extra_isize == 0) {
4869	/* The extra space is currently unused. Use it. */
4870	BUILD_BUG_ON(sizeof(struct ext4_inode) & 3);
4871	ei->i_extra_isize = sizeof(struct ext4_inode) -
4872	EXT4_GOOD_OLD_INODE_SIZE;
4873	} else {
4874	ret = ext4_iget_extra_inode(inode, raw_inode, ei);
4875	if (ret)
4876	goto bad_inode;
4877	}
4878	}
4879
4880	EXT4_INODE_GET_CTIME(inode, raw_inode);
4881	EXT4_INODE_GET_ATIME(inode, raw_inode);
4882	EXT4_INODE_GET_MTIME(inode, raw_inode);
4883	EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
4884
4885	if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
4886	u64 ivers = le32_to_cpu(raw_inode->i_disk_version);
4887
4888	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4889	if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4890	ivers |=
4891	(__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
4892	}
4893	ext4_inode_set_iversion_queried(inode, val: ivers);
4894	}
4895
4896	ret = 0;
4897	if (ei->i_file_acl &&
4898	!ext4_inode_block_valid(inode, start_blk: ei->i_file_acl, count: 1)) {
4899	ext4_error_inode(inode, function, line, 0,
4900	"iget: bad extended attribute block %llu",
4901	ei->i_file_acl);
4902	ret = -EFSCORRUPTED;
4903	goto bad_inode;
4904	} else if (!ext4_has_inline_data(inode)) {
4905	/* validate the block references in the inode */
4906	if (!(EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY) &&
4907	(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4908	(S_ISLNK(inode->i_mode) &&
4909	!ext4_inode_is_fast_symlink(inode)))) {
4910	if (ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))
4911	ret = ext4_ext_check_inode(inode);
4912	else
4913	ret = ext4_ind_check_inode(inode);
4914	}
4915	}
4916	if (ret)
4917	goto bad_inode;
4918
4919	if (S_ISREG(inode->i_mode)) {
4920	inode->i_op = &ext4_file_inode_operations;
4921	inode->i_fop = &ext4_file_operations;
4922	ext4_set_aops(inode);
4923	} else if (S_ISDIR(inode->i_mode)) {
4924	inode->i_op = &ext4_dir_inode_operations;
4925	inode->i_fop = &ext4_dir_operations;
4926	} else if (S_ISLNK(inode->i_mode)) {
4927	/* VFS does not allow setting these so must be corruption */
4928	if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) {
4929	ext4_error_inode(inode, function, line, 0,
4930	"iget: immutable or append flags "
4931	"not allowed on symlinks");
4932	ret = -EFSCORRUPTED;
4933	goto bad_inode;
4934	}
4935	if (IS_ENCRYPTED(inode)) {
4936	inode->i_op = &ext4_encrypted_symlink_inode_operations;
4937	} else if (ext4_inode_is_fast_symlink(inode)) {
4938	inode->i_link = (char *)ei->i_data;
4939	inode->i_op = &ext4_fast_symlink_inode_operations;
4940	nd_terminate_link(name: ei->i_data, len: inode->i_size,
4941	maxlen: sizeof(ei->i_data) - 1);
4942	} else {
4943	inode->i_op = &ext4_symlink_inode_operations;
4944	}
4945	} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
4946	S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
4947	inode->i_op = &ext4_special_inode_operations;
4948	if (raw_inode->i_block[0])
4949	init_special_inode(inode, inode->i_mode,
4950	old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
4951	else
4952	init_special_inode(inode, inode->i_mode,
4953	new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
4954	} else if (ino == EXT4_BOOT_LOADER_INO) {
4955	make_bad_inode(inode);
4956	} else {
4957	ret = -EFSCORRUPTED;
4958	ext4_error_inode(inode, function, line, 0,
4959	"iget: bogus i_mode (%o)", inode->i_mode);
4960	goto bad_inode;
4961	}
4962	if (IS_CASEFOLDED(inode) && !ext4_has_feature_casefold(sb: inode->i_sb)) {
4963	ext4_error_inode(inode, function, line, 0,
4964	"casefold flag without casefold feature");
4965	ret = -EFSCORRUPTED;
4966	goto bad_inode;
4967	}
4968	if ((err_str = check_igot_inode(inode, flags)) != NULL) {
4969	ext4_error_inode(inode, function, line, 0, err_str);
4970	ret = -EFSCORRUPTED;
4971	goto bad_inode;
4972	}
4973
4974	brelse(bh: iloc.bh);
4975	unlock_new_inode(inode);
4976	return inode;
4977
4978	bad_inode:
4979	brelse(bh: iloc.bh);
4980	iget_failed(inode);
4981	return ERR_PTR(error: ret);
4982	}
4983
4984	static void __ext4_update_other_inode_time(struct super_block *sb,
4985	unsigned long orig_ino,
4986	unsigned long ino,
4987	struct ext4_inode *raw_inode)
4988	{
4989	struct inode *inode;
4990
4991	inode = find_inode_by_ino_rcu(sb, ino);
4992	if (!inode)
4993	return;
4994
4995	if (!inode_is_dirtytime_only(inode))
4996	return;
4997
4998	spin_lock(lock: &inode->i_lock);
4999	if (inode_is_dirtytime_only(inode)) {
5000	struct ext4_inode_info *ei = EXT4_I(inode);
5001
5002	inode->i_state &= ~I_DIRTY_TIME;
5003	spin_unlock(lock: &inode->i_lock);
5004
5005	spin_lock(lock: &ei->i_raw_lock);
5006	EXT4_INODE_SET_CTIME(inode, raw_inode);
5007	EXT4_INODE_SET_MTIME(inode, raw_inode);
5008	EXT4_INODE_SET_ATIME(inode, raw_inode);
5009	ext4_inode_csum_set(inode, raw: raw_inode, ei);
5010	spin_unlock(lock: &ei->i_raw_lock);
5011	trace_ext4_other_inode_update_time(inode, orig_ino);
5012	return;
5013	}
5014	spin_unlock(lock: &inode->i_lock);
5015	}
5016
5017	/*
5018	* Opportunistically update the other time fields for other inodes in
5019	* the same inode table block.
5020	*/
5021	static void ext4_update_other_inodes_time(struct super_block *sb,
5022	unsigned long orig_ino, char *buf)
5023	{
5024	unsigned long ino;
5025	int i, inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
5026	int inode_size = EXT4_INODE_SIZE(sb);
5027
5028	/*
5029	* Calculate the first inode in the inode table block. Inode
5030	* numbers are one-based. That is, the first inode in a block
5031	* (assuming 4k blocks and 256 byte inodes) is (n*16 + 1).
5032	*/
5033	ino = ((orig_ino - 1) & ~(inodes_per_block - 1)) + 1;
5034	rcu_read_lock();
5035	for (i = 0; i < inodes_per_block; i++, ino++, buf += inode_size) {
5036	if (ino == orig_ino)
5037	continue;
5038	__ext4_update_other_inode_time(sb, orig_ino, ino,
5039	raw_inode: (struct ext4_inode *)buf);
5040	}
5041	rcu_read_unlock();
5042	}
5043
5044	/*
5045	* Post the struct inode info into an on-disk inode location in the
5046	* buffer-cache. This gobbles the caller's reference to the
5047	* buffer_head in the inode location struct.
5048	*
5049	* The caller must have write access to iloc->bh.
5050	*/
5051	static int ext4_do_update_inode(handle_t *handle,
5052	struct inode *inode,
5053	struct ext4_iloc *iloc)
5054	{
5055	struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
5056	struct ext4_inode_info *ei = EXT4_I(inode);
5057	struct buffer_head *bh = iloc->bh;
5058	struct super_block *sb = inode->i_sb;
5059	int err;
5060	int need_datasync = 0, set_large_file = 0;
5061
5062	spin_lock(lock: &ei->i_raw_lock);
5063
5064	/*
5065	* For fields not tracked in the in-memory inode, initialise them
5066	* to zero for new inodes.
5067	*/
5068	if (ext4_test_inode_state(inode, bit: EXT4_STATE_NEW))
5069	memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
5070
5071	if (READ_ONCE(ei->i_disksize) != ext4_isize(sb: inode->i_sb, raw_inode))
5072	need_datasync = 1;
5073	if (ei->i_disksize > 0x7fffffffULL) {
5074	if (!ext4_has_feature_large_file(sb) ||
5075	EXT4_SB(sb)->s_es->s_rev_level == cpu_to_le32(EXT4_GOOD_OLD_REV))
5076	set_large_file = 1;
5077	}
5078
5079	err = ext4_fill_raw_inode(inode, raw_inode);
5080	spin_unlock(lock: &ei->i_raw_lock);
5081	if (err) {
5082	EXT4_ERROR_INODE(inode, "corrupted inode contents");
5083	goto out_brelse;
5084	}
5085
5086	if (inode->i_sb->s_flags & SB_LAZYTIME)
5087	ext4_update_other_inodes_time(sb: inode->i_sb, orig_ino: inode->i_ino,
5088	buf: bh->b_data);
5089
5090	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
5091	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5092	if (err)
5093	goto out_error;
5094	ext4_clear_inode_state(inode, bit: EXT4_STATE_NEW);
5095	if (set_large_file) {
5096	BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get write access");
5097	err = ext4_journal_get_write_access(handle, sb,
5098	EXT4_SB(sb)->s_sbh,
5099	EXT4_JTR_NONE);
5100	if (err)
5101	goto out_error;
5102	lock_buffer(bh: EXT4_SB(sb)->s_sbh);
5103	ext4_set_feature_large_file(sb);
5104	ext4_superblock_csum_set(sb);
5105	unlock_buffer(bh: EXT4_SB(sb)->s_sbh);
5106	ext4_handle_sync(handle);
5107	err = ext4_handle_dirty_metadata(handle, NULL,
5108	EXT4_SB(sb)->s_sbh);
5109	}
5110	ext4_update_inode_fsync_trans(handle, inode, datasync: need_datasync);
5111	out_error:
5112	ext4_std_error(inode->i_sb, err);
5113	out_brelse:
5114	brelse(bh);
5115	return err;
5116	}
5117
5118	/*
5119	* ext4_write_inode()
5120	*
5121	* We are called from a few places:
5122	*
5123	* - Within generic_file_aio_write() -> generic_write_sync() for O_SYNC files.
5124	* Here, there will be no transaction running. We wait for any running
5125	* transaction to commit.
5126	*
5127	* - Within flush work (sys_sync(), kupdate and such).
5128	* We wait on commit, if told to.
5129	*
5130	* - Within iput_final() -> write_inode_now()
5131	* We wait on commit, if told to.
5132	*
5133	* In all cases it is actually safe for us to return without doing anything,
5134	* because the inode has been copied into a raw inode buffer in
5135	* ext4_mark_inode_dirty(). This is a correctness thing for WB_SYNC_ALL
5136	* writeback.
5137	*
5138	* Note that we are absolutely dependent upon all inode dirtiers doing the
5139	* right thing: they *must* call mark_inode_dirty() after dirtying info in
5140	* which we are interested.
5141	*
5142	* It would be a bug for them to not do this. The code:
5143	*
5144	* mark_inode_dirty(inode)
5145	* stuff();
5146	* inode->i_size = expr;
5147	*
5148	* is in error because write_inode() could occur while `stuff()' is running,
5149	* and the new i_size will be lost. Plus the inode will no longer be on the
5150	* superblock's dirty inode list.
5151	*/
5152	int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
5153	{
5154	int err;
5155
5156	if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
5157	return 0;
5158
5159	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
5160	return -EIO;
5161
5162	if (EXT4_SB(sb: inode->i_sb)->s_journal) {
5163	if (ext4_journal_current_handle()) {
5164	ext4_debug("called recursively, non-PF_MEMALLOC!\n");
5165	dump_stack();
5166	return -EIO;
5167	}
5168
5169	/*
5170	* No need to force transaction in WB_SYNC_NONE mode. Also
5171	* ext4_sync_fs() will force the commit after everything is
5172	* written.
5173	*/
5174	if (wbc->sync_mode != WB_SYNC_ALL || wbc->for_sync)
5175	return 0;
5176
5177	err = ext4_fc_commit(journal: EXT4_SB(sb: inode->i_sb)->s_journal,
5178	EXT4_I(inode)->i_sync_tid);
5179	} else {
5180	struct ext4_iloc iloc;
5181
5182	err = __ext4_get_inode_loc_noinmem(inode, iloc: &iloc);
5183	if (err)
5184	return err;
5185	/*
5186	* sync(2) will flush the whole buffer cache. No need to do
5187	* it here separately for each inode.
5188	*/
5189	if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync)
5190	sync_dirty_buffer(bh: iloc.bh);
5191	if (buffer_req(bh: iloc.bh) && !buffer_uptodate(bh: iloc.bh)) {
5192	ext4_error_inode_block(inode, iloc.bh->b_blocknr, EIO,
5193	"IO error syncing inode");
5194	err = -EIO;
5195	}
5196	brelse(bh: iloc.bh);
5197	}
5198	return err;
5199	}
5200
5201	/*
5202	* In data=journal mode ext4_journalled_invalidate_folio() may fail to invalidate
5203	* buffers that are attached to a folio straddling i_size and are undergoing
5204	* commit. In that case we have to wait for commit to finish and try again.
5205	*/
5206	static void ext4_wait_for_tail_page_commit(struct inode *inode)
5207	{
5208	unsigned offset;
5209	journal_t *journal = EXT4_SB(sb: inode->i_sb)->s_journal;
5210	tid_t commit_tid = 0;
5211	int ret;
5212
5213	offset = inode->i_size & (PAGE_SIZE - 1);
5214	/*
5215	* If the folio is fully truncated, we don't need to wait for any commit
5216	* (and we even should not as __ext4_journalled_invalidate_folio() may
5217	* strip all buffers from the folio but keep the folio dirty which can then
5218	* confuse e.g. concurrent ext4_writepages() seeing dirty folio without
5219	* buffers). Also we don't need to wait for any commit if all buffers in
5220	* the folio remain valid. This is most beneficial for the common case of
5221	* blocksize == PAGESIZE.
5222	*/
5223	if (!offset || offset > (PAGE_SIZE - i_blocksize(node: inode)))
5224	return;
5225	while (1) {
5226	struct folio *folio = filemap_lock_folio(mapping: inode->i_mapping,
5227	index: inode->i_size >> PAGE_SHIFT);
5228	if (IS_ERR(ptr: folio))
5229	return;
5230	ret = __ext4_journalled_invalidate_folio(folio, offset,
5231	length: folio_size(folio) - offset);
5232	folio_unlock(folio);
5233	folio_put(folio);
5234	if (ret != -EBUSY)
5235	return;
5236	commit_tid = 0;
5237	read_lock(&journal->j_state_lock);
5238	if (journal->j_committing_transaction)
5239	commit_tid = journal->j_committing_transaction->t_tid;
5240	read_unlock(&journal->j_state_lock);
5241	if (commit_tid)
5242	jbd2_log_wait_commit(journal, tid: commit_tid);
5243	}
5244	}
5245
5246	/*
5247	* ext4_setattr()
5248	*
5249	* Called from notify_change.
5250	*
5251	* We want to trap VFS attempts to truncate the file as soon as
5252	* possible. In particular, we want to make sure that when the VFS
5253	* shrinks i_size, we put the inode on the orphan list and modify
5254	* i_disksize immediately, so that during the subsequent flushing of
5255	* dirty pages and freeing of disk blocks, we can guarantee that any
5256	* commit will leave the blocks being flushed in an unused state on
5257	* disk. (On recovery, the inode will get truncated and the blocks will
5258	* be freed, so we have a strong guarantee that no future commit will
5259	* leave these blocks visible to the user.)
5260	*
5261	* Another thing we have to assure is that if we are in ordered mode
5262	* and inode is still attached to the committing transaction, we must
5263	* we start writeout of all the dirty pages which are being truncated.
5264	* This way we are sure that all the data written in the previous
5265	* transaction are already on disk (truncate waits for pages under
5266	* writeback).
5267	*
5268	* Called with inode->i_rwsem down.
5269	*/
5270	int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
5271	struct iattr *attr)
5272	{
5273	struct inode *inode = d_inode(dentry);
5274	int error, rc = 0;
5275	int orphan = 0;
5276	const unsigned int ia_valid = attr->ia_valid;
5277	bool inc_ivers = true;
5278
5279	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
5280	return -EIO;
5281
5282	if (unlikely(IS_IMMUTABLE(inode)))
5283	return -EPERM;
5284
5285	if (unlikely(IS_APPEND(inode) &&
5286	(ia_valid & (ATTR_MODE | ATTR_UID |
5287	ATTR_GID | ATTR_TIMES_SET))))
5288	return -EPERM;
5289
5290	error = setattr_prepare(idmap, dentry, attr);
5291	if (error)
5292	return error;
5293
5294	error = fscrypt_prepare_setattr(dentry, attr);
5295	if (error)
5296	return error;
5297
5298	error = fsverity_prepare_setattr(dentry, attr);
5299	if (error)
5300	return error;
5301
5302	if (is_quota_modification(idmap, inode, ia: attr)) {
5303	error = dquot_initialize(inode);
5304	if (error)
5305	return error;
5306	}
5307
5308	if (i_uid_needs_update(idmap, attr, inode) ||
5309	i_gid_needs_update(idmap, attr, inode)) {
5310	handle_t *handle;
5311
5312	/* (user+group)*(old+new) structure, inode write (sb,
5313	* inode block, ? - but truncate inode update has it) */
5314	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5315	(EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) +
5316	EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)) + 3);
5317	if (IS_ERR(ptr: handle)) {
5318	error = PTR_ERR(ptr: handle);
5319	goto err_out;
5320	}
5321
5322	/* dquot_transfer() calls back ext4_get_inode_usage() which
5323	* counts xattr inode references.
5324	*/
5325	down_read(sem: &EXT4_I(inode)->xattr_sem);
5326	error = dquot_transfer(idmap, inode, iattr: attr);
5327	up_read(sem: &EXT4_I(inode)->xattr_sem);
5328
5329	if (error) {
5330	ext4_journal_stop(handle);
5331	return error;
5332	}
5333	/* Update corresponding info in inode so that everything is in
5334	* one transaction */
5335	i_uid_update(idmap, attr, inode);
5336	i_gid_update(idmap, attr, inode);
5337	error = ext4_mark_inode_dirty(handle, inode);
5338	ext4_journal_stop(handle);
5339	if (unlikely(error)) {
5340	return error;
5341	}
5342	}
5343
5344	if (attr->ia_valid & ATTR_SIZE) {
5345	handle_t *handle;
5346	loff_t oldsize = inode->i_size;
5347	loff_t old_disksize;
5348	int shrink = (attr->ia_size < inode->i_size);
5349
5350	if (!(ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS))) {
5351	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
5352
5353	if (attr->ia_size > sbi->s_bitmap_maxbytes) {
5354	return -EFBIG;
5355	}
5356	}
5357	if (!S_ISREG(inode->i_mode)) {
5358	return -EINVAL;
5359	}
5360
5361	if (attr->ia_size == inode->i_size)
5362	inc_ivers = false;
5363
5364	if (shrink) {
5365	if (ext4_should_order_data(inode)) {
5366	error = ext4_begin_ordered_truncate(inode,
5367	new_size: attr->ia_size);
5368	if (error)
5369	goto err_out;
5370	}
5371	/*
5372	* Blocks are going to be removed from the inode. Wait
5373	* for dio in flight.
5374	*/
5375	inode_dio_wait(inode);
5376	}
5377
5378	filemap_invalidate_lock(mapping: inode->i_mapping);
5379
5380	rc = ext4_break_layouts(inode);
5381	if (rc) {
5382	filemap_invalidate_unlock(mapping: inode->i_mapping);
5383	goto err_out;
5384	}
5385
5386	if (attr->ia_size != inode->i_size) {
5387	handle = ext4_journal_start(inode, EXT4_HT_INODE, 3);
5388	if (IS_ERR(ptr: handle)) {
5389	error = PTR_ERR(ptr: handle);
5390	goto out_mmap_sem;
5391	}
5392	if (ext4_handle_valid(handle) && shrink) {
5393	error = ext4_orphan_add(handle, inode);
5394	orphan = 1;
5395	}
5396	/*
5397	* Update c/mtime on truncate up, ext4_truncate() will
5398	* update c/mtime in shrink case below
5399	*/
5400	if (!shrink)
5401	inode_set_mtime_to_ts(inode,
5402	ts: inode_set_ctime_current(inode));
5403
5404	if (shrink)
5405	ext4_fc_track_range(handle, inode,
5406	start: (attr->ia_size > 0 ? attr->ia_size - 1 : 0) >>
5407	inode->i_sb->s_blocksize_bits,
5408	EXT_MAX_BLOCKS - 1);
5409	else
5410	ext4_fc_track_range(
5411	handle, inode,
5412	start: (oldsize > 0 ? oldsize - 1 : oldsize) >>
5413	inode->i_sb->s_blocksize_bits,
5414	end: (attr->ia_size > 0 ? attr->ia_size - 1 : 0) >>
5415	inode->i_sb->s_blocksize_bits);
5416
5417	down_write(sem: &EXT4_I(inode)->i_data_sem);
5418	old_disksize = EXT4_I(inode)->i_disksize;
5419	EXT4_I(inode)->i_disksize = attr->ia_size;
5420	rc = ext4_mark_inode_dirty(handle, inode);
5421	if (!error)
5422	error = rc;
5423	/*
5424	* We have to update i_size under i_data_sem together
5425	* with i_disksize to avoid races with writeback code
5426	* running ext4_wb_update_i_disksize().
5427	*/
5428	if (!error)
5429	i_size_write(inode, i_size: attr->ia_size);
5430	else
5431	EXT4_I(inode)->i_disksize = old_disksize;
5432	up_write(sem: &EXT4_I(inode)->i_data_sem);
5433	ext4_journal_stop(handle);
5434	if (error)
5435	goto out_mmap_sem;
5436	if (!shrink) {
5437	pagecache_isize_extended(inode, from: oldsize,
5438	to: inode->i_size);
5439	} else if (ext4_should_journal_data(inode)) {
5440	ext4_wait_for_tail_page_commit(inode);
5441	}
5442	}
5443
5444	/*
5445	* Truncate pagecache after we've waited for commit
5446	* in data=journal mode to make pages freeable.
5447	*/
5448	truncate_pagecache(inode, new: inode->i_size);
5449	/*
5450	* Call ext4_truncate() even if i_size didn't change to
5451	* truncate possible preallocated blocks.
5452	*/
5453	if (attr->ia_size <= oldsize) {
5454	rc = ext4_truncate(inode);
5455	if (rc)
5456	error = rc;
5457	}
5458	out_mmap_sem:
5459	filemap_invalidate_unlock(mapping: inode->i_mapping);
5460	}
5461
5462	if (!error) {
5463	if (inc_ivers)
5464	inode_inc_iversion(inode);
5465	setattr_copy(idmap, inode, attr);
5466	mark_inode_dirty(inode);
5467	}
5468
5469	/*
5470	* If the call to ext4_truncate failed to get a transaction handle at
5471	* all, we need to clean up the in-core orphan list manually.
5472	*/
5473	if (orphan && inode->i_nlink)
5474	ext4_orphan_del(NULL, inode);
5475
5476	if (!error && (ia_valid & ATTR_MODE))
5477	rc = posix_acl_chmod(idmap, dentry, inode->i_mode);
5478
5479	err_out:
5480	if (error)
5481	ext4_std_error(inode->i_sb, error);
5482	if (!error)
5483	error = rc;
5484	return error;
5485	}
5486
5487	u32 ext4_dio_alignment(struct inode *inode)
5488	{
5489	if (fsverity_active(inode))
5490	return 0;
5491	if (ext4_should_journal_data(inode))
5492	return 0;
5493	if (ext4_has_inline_data(inode))
5494	return 0;
5495	if (IS_ENCRYPTED(inode)) {
5496	if (!fscrypt_dio_supported(inode))
5497	return 0;
5498	return i_blocksize(node: inode);
5499	}
5500	return 1; /* use the iomap defaults */
5501	}
5502
5503	int ext4_getattr(struct mnt_idmap *idmap, const struct path *path,
5504	struct kstat *stat, u32 request_mask, unsigned int query_flags)
5505	{
5506	struct inode *inode = d_inode(dentry: path->dentry);
5507	struct ext4_inode *raw_inode;
5508	struct ext4_inode_info *ei = EXT4_I(inode);
5509	unsigned int flags;
5510
5511	if ((request_mask & STATX_BTIME) &&
5512	EXT4_FITS_IN_INODE(raw_inode, ei, i_crtime)) {
5513	stat->result_mask |= STATX_BTIME;
5514	stat->btime.tv_sec = ei->i_crtime.tv_sec;
5515	stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
5516	}
5517
5518	/*
5519	* Return the DIO alignment restrictions if requested. We only return
5520	* this information when requested, since on encrypted files it might
5521	* take a fair bit of work to get if the file wasn't opened recently.
5522	*/
5523	if ((request_mask & STATX_DIOALIGN) && S_ISREG(inode->i_mode)) {
5524	u32 dio_align = ext4_dio_alignment(inode);
5525
5526	stat->result_mask |= STATX_DIOALIGN;
5527	if (dio_align == 1) {
5528	struct block_device *bdev = inode->i_sb->s_bdev;
5529
5530	/* iomap defaults */
5531	stat->dio_mem_align = bdev_dma_alignment(bdev) + 1;
5532	stat->dio_offset_align = bdev_logical_block_size(bdev);
5533	} else {
5534	stat->dio_mem_align = dio_align;
5535	stat->dio_offset_align = dio_align;
5536	}
5537	}
5538
5539	flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
5540	if (flags & EXT4_APPEND_FL)
5541	stat->attributes |= STATX_ATTR_APPEND;
5542	if (flags & EXT4_COMPR_FL)
5543	stat->attributes |= STATX_ATTR_COMPRESSED;
5544	if (flags & EXT4_ENCRYPT_FL)
5545	stat->attributes |= STATX_ATTR_ENCRYPTED;
5546	if (flags & EXT4_IMMUTABLE_FL)
5547	stat->attributes |= STATX_ATTR_IMMUTABLE;
5548	if (flags & EXT4_NODUMP_FL)
5549	stat->attributes |= STATX_ATTR_NODUMP;
5550	if (flags & EXT4_VERITY_FL)
5551	stat->attributes |= STATX_ATTR_VERITY;
5552
5553	stat->attributes_mask |= (STATX_ATTR_APPEND |
5554	STATX_ATTR_COMPRESSED |
5555	STATX_ATTR_ENCRYPTED |
5556	STATX_ATTR_IMMUTABLE |
5557	STATX_ATTR_NODUMP |
5558	STATX_ATTR_VERITY);
5559
5560	generic_fillattr(idmap, request_mask, inode, stat);
5561	return 0;
5562	}
5563
5564	int ext4_file_getattr(struct mnt_idmap *idmap,
5565	const struct path *path, struct kstat *stat,
5566	u32 request_mask, unsigned int query_flags)
5567	{
5568	struct inode *inode = d_inode(dentry: path->dentry);
5569	u64 delalloc_blocks;
5570
5571	ext4_getattr(idmap, path, stat, request_mask, query_flags);
5572
5573	/*
5574	* If there is inline data in the inode, the inode will normally not
5575	* have data blocks allocated (it may have an external xattr block).
5576	* Report at least one sector for such files, so tools like tar, rsync,
5577	* others don't incorrectly think the file is completely sparse.
5578	*/
5579	if (unlikely(ext4_has_inline_data(inode)))
5580	stat->blocks += (stat->size + 511) >> 9;
5581
5582	/*
5583	* We can't update i_blocks if the block allocation is delayed
5584	* otherwise in the case of system crash before the real block
5585	* allocation is done, we will have i_blocks inconsistent with
5586	* on-disk file blocks.
5587	* We always keep i_blocks updated together with real
5588	* allocation. But to not confuse with user, stat
5589	* will return the blocks that include the delayed allocation
5590	* blocks for this file.
5591	*/
5592	delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
5593	EXT4_I(inode)->i_reserved_data_blocks);
5594	stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits - 9);
5595	return 0;
5596	}
5597
5598	static int ext4_index_trans_blocks(struct inode *inode, int lblocks,
5599	int pextents)
5600	{
5601	if (!(ext4_test_inode_flag(inode, bit: EXT4_INODE_EXTENTS)))
5602	return ext4_ind_trans_blocks(inode, nrblocks: lblocks);
5603	return ext4_ext_index_trans_blocks(inode, extents: pextents);
5604	}
5605
5606	/*
5607	* Account for index blocks, block groups bitmaps and block group
5608	* descriptor blocks if modify datablocks and index blocks
5609	* worse case, the indexs blocks spread over different block groups
5610	*
5611	* If datablocks are discontiguous, they are possible to spread over
5612	* different block groups too. If they are contiguous, with flexbg,
5613	* they could still across block group boundary.
5614	*
5615	* Also account for superblock, inode, quota and xattr blocks
5616	*/
5617	static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
5618	int pextents)
5619	{
5620	ext4_group_t groups, ngroups = ext4_get_groups_count(sb: inode->i_sb);
5621	int gdpblocks;
5622	int idxblocks;
5623	int ret;
5624
5625	/*
5626	* How many index blocks need to touch to map @lblocks logical blocks
5627	* to @pextents physical extents?
5628	*/
5629	idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents);
5630
5631	ret = idxblocks;
5632
5633	/*
5634	* Now let's see how many group bitmaps and group descriptors need
5635	* to account
5636	*/
5637	groups = idxblocks + pextents;
5638	gdpblocks = groups;
5639	if (groups > ngroups)
5640	groups = ngroups;
5641	if (groups > EXT4_SB(sb: inode->i_sb)->s_gdb_count)
5642	gdpblocks = EXT4_SB(sb: inode->i_sb)->s_gdb_count;
5643
5644	/* bitmaps and block group descriptor blocks */
5645	ret += groups + gdpblocks;
5646
5647	/* Blocks for super block, inode, quota and xattr blocks */
5648	ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
5649
5650	return ret;
5651	}
5652
5653	/*
5654	* Calculate the total number of credits to reserve to fit
5655	* the modification of a single pages into a single transaction,
5656	* which may include multiple chunks of block allocations.
5657	*
5658	* This could be called via ext4_write_begin()
5659	*
5660	* We need to consider the worse case, when
5661	* one new block per extent.
5662	*/
5663	int ext4_writepage_trans_blocks(struct inode *inode)
5664	{
5665	int bpp = ext4_journal_blocks_per_page(inode);
5666	int ret;
5667
5668	ret = ext4_meta_trans_blocks(inode, lblocks: bpp, pextents: bpp);
5669
5670	/* Account for data blocks for journalled mode */
5671	if (ext4_should_journal_data(inode))
5672	ret += bpp;
5673	return ret;
5674	}
5675
5676	/*
5677	* Calculate the journal credits for a chunk of data modification.
5678	*
5679	* This is called from DIO, fallocate or whoever calling
5680	* ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
5681	*
5682	* journal buffers for data blocks are not included here, as DIO
5683	* and fallocate do no need to journal data buffers.
5684	*/
5685	int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
5686	{
5687	return ext4_meta_trans_blocks(inode, lblocks: nrblocks, pextents: 1);
5688	}
5689
5690	/*
5691	* The caller must have previously called ext4_reserve_inode_write().
5692	* Give this, we know that the caller already has write access to iloc->bh.
5693	*/
5694	int ext4_mark_iloc_dirty(handle_t *handle,
5695	struct inode *inode, struct ext4_iloc *iloc)
5696	{
5697	int err = 0;
5698
5699	if (unlikely(ext4_forced_shutdown(inode->i_sb))) {
5700	put_bh(bh: iloc->bh);
5701	return -EIO;
5702	}
5703	ext4_fc_track_inode(handle, inode);
5704
5705	/* the do_update_inode consumes one bh->b_count */
5706	get_bh(bh: iloc->bh);
5707
5708	/* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5709	err = ext4_do_update_inode(handle, inode, iloc);
5710	put_bh(bh: iloc->bh);
5711	return err;
5712	}
5713
5714	/*
5715	* On success, We end up with an outstanding reference count against
5716	* iloc->bh. This _must_ be cleaned up later.
5717	*/
5718
5719	int
5720	ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
5721	struct ext4_iloc *iloc)
5722	{
5723	int err;
5724
5725	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
5726	return -EIO;
5727
5728	err = ext4_get_inode_loc(inode, iloc);
5729	if (!err) {
5730	BUFFER_TRACE(iloc->bh, "get_write_access");
5731	err = ext4_journal_get_write_access(handle, inode->i_sb,
5732	iloc->bh, EXT4_JTR_NONE);
5733	if (err) {
5734	brelse(bh: iloc->bh);
5735	iloc->bh = NULL;
5736	}
5737	}
5738	ext4_std_error(inode->i_sb, err);
5739	return err;
5740	}
5741
5742	static int __ext4_expand_extra_isize(struct inode *inode,
5743	unsigned int new_extra_isize,
5744	struct ext4_iloc *iloc,
5745	handle_t *handle, int *no_expand)
5746	{
5747	struct ext4_inode *raw_inode;
5748	struct ext4_xattr_ibody_header *header;
5749	unsigned int inode_size = EXT4_INODE_SIZE(inode->i_sb);
5750	struct ext4_inode_info *ei = EXT4_I(inode);
5751	int error;
5752
5753	/* this was checked at iget time, but double check for good measure */
5754	if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) ||
5755	(ei->i_extra_isize & 3)) {
5756	EXT4_ERROR_INODE(inode, "bad extra_isize %u (inode size %u)",
5757	ei->i_extra_isize,
5758	EXT4_INODE_SIZE(inode->i_sb));
5759	return -EFSCORRUPTED;
5760	}
5761	if ((new_extra_isize < ei->i_extra_isize) ||
5762	(new_extra_isize < 4) ||
5763	(new_extra_isize > inode_size - EXT4_GOOD_OLD_INODE_SIZE))
5764	return -EINVAL; /* Should never happen */
5765
5766	raw_inode = ext4_raw_inode(iloc);
5767
5768	header = IHDR(inode, raw_inode);
5769
5770	/* No extended attributes present */
5771	if (!ext4_test_inode_state(inode, bit: EXT4_STATE_XATTR) ||
5772	header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
5773	memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
5774	EXT4_I(inode)->i_extra_isize, 0,
5775	new_extra_isize - EXT4_I(inode)->i_extra_isize);
5776	EXT4_I(inode)->i_extra_isize = new_extra_isize;
5777	return 0;
5778	}
5779
5780	/*
5781	* We may need to allocate external xattr block so we need quotas
5782	* initialized. Here we can be called with various locks held so we
5783	* cannot affort to initialize quotas ourselves. So just bail.
5784	*/
5785	if (dquot_initialize_needed(inode))
5786	return -EAGAIN;
5787
5788	/* try to expand with EAs present */
5789	error = ext4_expand_extra_isize_ea(inode, new_extra_isize,
5790	raw_inode, handle);
5791	if (error) {
5792	/*
5793	* Inode size expansion failed; don't try again
5794	*/
5795	*no_expand = 1;
5796	}
5797
5798	return error;
5799	}
5800
5801	/*
5802	* Expand an inode by new_extra_isize bytes.
5803	* Returns 0 on success or negative error number on failure.
5804	*/
5805	static int ext4_try_to_expand_extra_isize(struct inode *inode,
5806	unsigned int new_extra_isize,
5807	struct ext4_iloc iloc,
5808	handle_t *handle)
5809	{
5810	int no_expand;
5811	int error;
5812
5813	if (ext4_test_inode_state(inode, bit: EXT4_STATE_NO_EXPAND))
5814	return -EOVERFLOW;
5815
5816	/*
5817	* In nojournal mode, we can immediately attempt to expand
5818	* the inode. When journaled, we first need to obtain extra
5819	* buffer credits since we may write into the EA block
5820	* with this same handle. If journal_extend fails, then it will
5821	* only result in a minor loss of functionality for that inode.
5822	* If this is felt to be critical, then e2fsck should be run to
5823	* force a large enough s_min_extra_isize.
5824	*/
5825	if (ext4_journal_extend(handle,
5826	EXT4_DATA_TRANS_BLOCKS(inode->i_sb), revoke: 0) != 0)
5827	return -ENOSPC;
5828
5829	if (ext4_write_trylock_xattr(inode, save: &no_expand) == 0)
5830	return -EBUSY;
5831
5832	error = __ext4_expand_extra_isize(inode, new_extra_isize, iloc: &iloc,
5833	handle, no_expand: &no_expand);
5834	ext4_write_unlock_xattr(inode, save: &no_expand);
5835
5836	return error;
5837	}
5838
5839	int ext4_expand_extra_isize(struct inode *inode,
5840	unsigned int new_extra_isize,
5841	struct ext4_iloc *iloc)
5842	{
5843	handle_t *handle;
5844	int no_expand;
5845	int error, rc;
5846
5847	if (ext4_test_inode_state(inode, bit: EXT4_STATE_NO_EXPAND)) {
5848	brelse(bh: iloc->bh);
5849	return -EOVERFLOW;
5850	}
5851
5852	handle = ext4_journal_start(inode, EXT4_HT_INODE,
5853	EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
5854	if (IS_ERR(ptr: handle)) {
5855	error = PTR_ERR(ptr: handle);
5856	brelse(bh: iloc->bh);
5857	return error;
5858	}
5859
5860	ext4_write_lock_xattr(inode, save: &no_expand);
5861
5862	BUFFER_TRACE(iloc->bh, "get_write_access");
5863	error = ext4_journal_get_write_access(handle, inode->i_sb, iloc->bh,
5864	EXT4_JTR_NONE);
5865	if (error) {
5866	brelse(bh: iloc->bh);
5867	goto out_unlock;
5868	}
5869
5870	error = __ext4_expand_extra_isize(inode, new_extra_isize, iloc,
5871	handle, no_expand: &no_expand);
5872
5873	rc = ext4_mark_iloc_dirty(handle, inode, iloc);
5874	if (!error)
5875	error = rc;
5876
5877	out_unlock:
5878	ext4_write_unlock_xattr(inode, save: &no_expand);
5879	ext4_journal_stop(handle);
5880	return error;
5881	}
5882
5883	/*
5884	* What we do here is to mark the in-core inode as clean with respect to inode
5885	* dirtiness (it may still be data-dirty).
5886	* This means that the in-core inode may be reaped by prune_icache
5887	* without having to perform any I/O. This is a very good thing,
5888	* because *any* task may call prune_icache - even ones which
5889	* have a transaction open against a different journal.
5890	*
5891	* Is this cheating? Not really. Sure, we haven't written the
5892	* inode out, but prune_icache isn't a user-visible syncing function.
5893	* Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
5894	* we start and wait on commits.
5895	*/
5896	int __ext4_mark_inode_dirty(handle_t *handle, struct inode *inode,
5897	const char *func, unsigned int line)
5898	{
5899	struct ext4_iloc iloc;
5900	struct ext4_sb_info *sbi = EXT4_SB(sb: inode->i_sb);
5901	int err;
5902
5903	might_sleep();
5904	trace_ext4_mark_inode_dirty(inode, _RET_IP_);
5905	err = ext4_reserve_inode_write(handle, inode, iloc: &iloc);
5906	if (err)
5907	goto out;
5908
5909	if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize)
5910	ext4_try_to_expand_extra_isize(inode, new_extra_isize: sbi->s_want_extra_isize,
5911	iloc, handle);
5912
5913	err = ext4_mark_iloc_dirty(handle, inode, iloc: &iloc);
5914	out:
5915	if (unlikely(err))
5916	ext4_error_inode_err(inode, func, line, 0, err,
5917	"mark_inode_dirty error");
5918	return err;
5919	}
5920
5921	/*
5922	* ext4_dirty_inode() is called from __mark_inode_dirty()
5923	*
5924	* We're really interested in the case where a file is being extended.
5925	* i_size has been changed by generic_commit_write() and we thus need
5926	* to include the updated inode in the current transaction.
5927	*
5928	* Also, dquot_alloc_block() will always dirty the inode when blocks
5929	* are allocated to the file.
5930	*
5931	* If the inode is marked synchronous, we don't honour that here - doing
5932	* so would cause a commit on atime updates, which we don't bother doing.
5933	* We handle synchronous inodes at the highest possible level.
5934	*/
5935	void ext4_dirty_inode(struct inode *inode, int flags)
5936	{
5937	handle_t *handle;
5938
5939	handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
5940	if (IS_ERR(ptr: handle))
5941	return;
5942	ext4_mark_inode_dirty(handle, inode);
5943	ext4_journal_stop(handle);
5944	}
5945
5946	int ext4_change_inode_journal_flag(struct inode *inode, int val)
5947	{
5948	journal_t *journal;
5949	handle_t *handle;
5950	int err;
5951	int alloc_ctx;
5952
5953	/*
5954	* We have to be very careful here: changing a data block's
5955	* journaling status dynamically is dangerous. If we write a
5956	* data block to the journal, change the status and then delete
5957	* that block, we risk forgetting to revoke the old log record
5958	* from the journal and so a subsequent replay can corrupt data.
5959	* So, first we make sure that the journal is empty and that
5960	* nobody is changing anything.
5961	*/
5962
5963	journal = EXT4_JOURNAL(inode);
5964	if (!journal)
5965	return 0;
5966	if (is_journal_aborted(journal))
5967	return -EROFS;
5968
5969	/* Wait for all existing dio workers */
5970	inode_dio_wait(inode);
5971
5972	/*
5973	* Before flushing the journal and switching inode's aops, we have
5974	* to flush all dirty data the inode has. There can be outstanding
5975	* delayed allocations, there can be unwritten extents created by
5976	* fallocate or buffered writes in dioread_nolock mode covered by
5977	* dirty data which can be converted only after flushing the dirty
5978	* data (and journalled aops don't know how to handle these cases).
5979	*/
5980	if (val) {
5981	filemap_invalidate_lock(mapping: inode->i_mapping);
5982	err = filemap_write_and_wait(mapping: inode->i_mapping);
5983	if (err < 0) {
5984	filemap_invalidate_unlock(mapping: inode->i_mapping);
5985	return err;
5986	}
5987	}
5988
5989	alloc_ctx = ext4_writepages_down_write(sb: inode->i_sb);
5990	jbd2_journal_lock_updates(journal);
5991
5992	/*
5993	* OK, there are no updates running now, and all cached data is
5994	* synced to disk. We are now in a completely consistent state
5995	* which doesn't have anything in the journal, and we know that
5996	* no filesystem updates are running, so it is safe to modify
5997	* the inode's in-core data-journaling state flag now.
5998	*/
5999
6000	if (val)
6001	ext4_set_inode_flag(inode, bit: EXT4_INODE_JOURNAL_DATA);
6002	else {
6003	err = jbd2_journal_flush(journal, flags: 0);
6004	if (err < 0) {
6005	jbd2_journal_unlock_updates(journal);
6006	ext4_writepages_up_write(sb: inode->i_sb, ctx: alloc_ctx);
6007	return err;
6008	}
6009	ext4_clear_inode_flag(inode, bit: EXT4_INODE_JOURNAL_DATA);
6010	}
6011	ext4_set_aops(inode);
6012
6013	jbd2_journal_unlock_updates(journal);
6014	ext4_writepages_up_write(sb: inode->i_sb, ctx: alloc_ctx);
6015
6016	if (val)
6017	filemap_invalidate_unlock(mapping: inode->i_mapping);
6018
6019	/* Finally we can mark the inode as dirty. */
6020
6021	handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
6022	if (IS_ERR(ptr: handle))
6023	return PTR_ERR(ptr: handle);
6024
6025	ext4_fc_mark_ineligible(sb: inode->i_sb,
6026	reason: EXT4_FC_REASON_JOURNAL_FLAG_CHANGE, handle);
6027	err = ext4_mark_inode_dirty(handle, inode);
6028	ext4_handle_sync(handle);
6029	ext4_journal_stop(handle);
6030	ext4_std_error(inode->i_sb, err);
6031
6032	return err;
6033	}
6034
6035	static int ext4_bh_unmapped(handle_t *handle, struct inode *inode,
6036	struct buffer_head *bh)
6037	{
6038	return !buffer_mapped(bh);
6039	}
6040
6041	vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf)
6042	{
6043	struct vm_area_struct *vma = vmf->vma;
6044	struct folio *folio = page_folio(vmf->page);
6045	loff_t size;
6046	unsigned long len;
6047	int err;
6048	vm_fault_t ret;
6049	struct file *file = vma->vm_file;
6050	struct inode *inode = file_inode(f: file);
6051	struct address_space *mapping = inode->i_mapping;
6052	handle_t *handle;
6053	get_block_t *get_block;
6054	int retries = 0;
6055
6056	if (unlikely(IS_IMMUTABLE(inode)))
6057	return VM_FAULT_SIGBUS;
6058
6059	sb_start_pagefault(sb: inode->i_sb);
6060	file_update_time(file: vma->vm_file);
6061
6062	filemap_invalidate_lock_shared(mapping);
6063
6064	err = ext4_convert_inline_data(inode);
6065	if (err)
6066	goto out_ret;
6067
6068	/*
6069	* On data journalling we skip straight to the transaction handle:
6070	* there's no delalloc; page truncated will be checked later; the
6071	* early return w/ all buffers mapped (calculates size/len) can't
6072	* be used; and there's no dioread_nolock, so only ext4_get_block.
6073	*/
6074	if (ext4_should_journal_data(inode))
6075	goto retry_alloc;
6076
6077	/* Delalloc case is easy... */
6078	if (test_opt(inode->i_sb, DELALLOC) &&
6079	!ext4_nonda_switch(sb: inode->i_sb)) {
6080	do {
6081	err = block_page_mkwrite(vma, vmf,
6082	get_block: ext4_da_get_block_prep);
6083	} while (err == -ENOSPC &&
6084	ext4_should_retry_alloc(sb: inode->i_sb, retries: &retries));
6085	goto out_ret;
6086	}
6087
6088	folio_lock(folio);
6089	size = i_size_read(inode);
6090	/* Page got truncated from under us? */
6091	if (folio->mapping != mapping || folio_pos(folio) > size) {
6092	folio_unlock(folio);
6093	ret = VM_FAULT_NOPAGE;
6094	goto out;
6095	}
6096
6097	len = folio_size(folio);
6098	if (folio_pos(folio) + len > size)
6099	len = size - folio_pos(folio);
6100	/*
6101	* Return if we have all the buffers mapped. This avoids the need to do
6102	* journal_start/journal_stop which can block and take a long time
6103	*
6104	* This cannot be done for data journalling, as we have to add the
6105	* inode to the transaction's list to writeprotect pages on commit.
6106	*/
6107	if (folio_buffers(folio)) {
6108	if (!ext4_walk_page_buffers(NULL, inode, folio_buffers(folio),
6109	from: 0, to: len, NULL,
6110	fn: ext4_bh_unmapped)) {
6111	/* Wait so that we don't change page under IO */
6112	folio_wait_stable(folio);
6113	ret = VM_FAULT_LOCKED;
6114	goto out;
6115	}
6116	}
6117	folio_unlock(folio);
6118	/* OK, we need to fill the hole... */
6119	if (ext4_should_dioread_nolock(inode))
6120	get_block = ext4_get_block_unwritten;
6121	else
6122	get_block = ext4_get_block;
6123	retry_alloc:
6124	handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
6125	ext4_writepage_trans_blocks(inode));
6126	if (IS_ERR(ptr: handle)) {
6127	ret = VM_FAULT_SIGBUS;
6128	goto out;
6129	}
6130	/*
6131	* Data journalling can't use block_page_mkwrite() because it
6132	* will set_buffer_dirty() before do_journal_get_write_access()
6133	* thus might hit warning messages for dirty metadata buffers.
6134	*/
6135	if (!ext4_should_journal_data(inode)) {
6136	err = block_page_mkwrite(vma, vmf, get_block);
6137	} else {
6138	folio_lock(folio);
6139	size = i_size_read(inode);
6140	/* Page got truncated from under us? */
6141	if (folio->mapping != mapping || folio_pos(folio) > size) {
6142	ret = VM_FAULT_NOPAGE;
6143	goto out_error;
6144	}
6145
6146	len = folio_size(folio);
6147	if (folio_pos(folio) + len > size)
6148	len = size - folio_pos(folio);
6149
6150	err = __block_write_begin(page: &folio->page, pos: 0, len, get_block: ext4_get_block);
6151	if (!err) {
6152	ret = VM_FAULT_SIGBUS;
6153	if (ext4_journal_folio_buffers(handle, folio, len))
6154	goto out_error;
6155	} else {
6156	folio_unlock(folio);
6157	}
6158	}
6159	ext4_journal_stop(handle);
6160	if (err == -ENOSPC && ext4_should_retry_alloc(sb: inode->i_sb, retries: &retries))
6161	goto retry_alloc;
6162	out_ret:
6163	ret = vmf_fs_error(err);
6164	out:
6165	filemap_invalidate_unlock_shared(mapping);
6166	sb_end_pagefault(sb: inode->i_sb);
6167	return ret;
6168	out_error:
6169	folio_unlock(folio);
6170	ext4_journal_stop(handle);
6171	goto out;
6172	}
6173