1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#ifndef BTRFS_INODE_H
7#define BTRFS_INODE_H
8
9#include <linux/hash.h>
10#include <linux/refcount.h>
11#include <linux/spinlock.h>
12#include <linux/mutex.h>
13#include <linux/rwsem.h>
14#include <linux/fs.h>
15#include <linux/mm.h>
16#include <linux/compiler.h>
17#include <linux/fscrypt.h>
18#include <linux/lockdep.h>
19#include <uapi/linux/btrfs_tree.h>
20#include <trace/events/btrfs.h>
21#include "block-rsv.h"
22#include "btrfs_inode.h"
23#include "extent_map.h"
24#include "extent_io.h"
25#include "extent-io-tree.h"
26#include "ordered-data.h"
27#include "delayed-inode.h"
28
29struct extent_state;
30struct posix_acl;
31struct iov_iter;
32struct writeback_control;
33struct btrfs_root;
34struct btrfs_fs_info;
35struct btrfs_trans_handle;
36
37/*
38 * Since we search a directory based on f_pos (struct dir_context::pos) we have
39 * to start at 2 since '.' and '..' have f_pos of 0 and 1 respectively, so
40 * everybody else has to start at 2 (see btrfs_real_readdir() and dir_emit_dots()).
41 */
42#define BTRFS_DIR_START_INDEX 2
43
44/*
45 * ordered_data_close is set by truncate when a file that used
46 * to have good data has been truncated to zero. When it is set
47 * the btrfs file release call will add this inode to the
48 * ordered operations list so that we make sure to flush out any
49 * new data the application may have written before commit.
50 */
51enum {
52 BTRFS_INODE_FLUSH_ON_CLOSE,
53 BTRFS_INODE_DUMMY,
54 BTRFS_INODE_IN_DEFRAG,
55 BTRFS_INODE_HAS_ASYNC_EXTENT,
56 /*
57 * Always set under the VFS' inode lock, otherwise it can cause races
58 * during fsync (we start as a fast fsync and then end up in a full
59 * fsync racing with ordered extent completion).
60 */
61 BTRFS_INODE_NEEDS_FULL_SYNC,
62 BTRFS_INODE_COPY_EVERYTHING,
63 BTRFS_INODE_HAS_PROPS,
64 BTRFS_INODE_SNAPSHOT_FLUSH,
65 /*
66 * Set and used when logging an inode and it serves to signal that an
67 * inode does not have xattrs, so subsequent fsyncs can avoid searching
68 * for xattrs to log. This bit must be cleared whenever a xattr is added
69 * to an inode.
70 */
71 BTRFS_INODE_NO_XATTRS,
72 /*
73 * Set when we are in a context where we need to start a transaction and
74 * have dirty pages with the respective file range locked. This is to
75 * ensure that when reserving space for the transaction, if we are low
76 * on available space and need to flush delalloc, we will not flush
77 * delalloc for this inode, because that could result in a deadlock (on
78 * the file range, inode's io_tree).
79 */
80 BTRFS_INODE_NO_DELALLOC_FLUSH,
81 /*
82 * Set when we are working on enabling verity for a file. Computing and
83 * writing the whole Merkle tree can take a while so we want to prevent
84 * races where two separate tasks attempt to simultaneously start verity
85 * on the same file.
86 */
87 BTRFS_INODE_VERITY_IN_PROGRESS,
88 /* Set when this inode is a free space inode. */
89 BTRFS_INODE_FREE_SPACE_INODE,
90 /* Set when there are no capabilities in XATTs for the inode. */
91 BTRFS_INODE_NO_CAP_XATTR,
92};
93
94/* in memory btrfs inode */
95struct btrfs_inode {
96 /* which subvolume this inode belongs to */
97 struct btrfs_root *root;
98
99 /* key used to find this inode on disk. This is used by the code
100 * to read in roots of subvolumes
101 */
102 struct btrfs_key location;
103
104 /* Cached value of inode property 'compression'. */
105 u8 prop_compress;
106
107 /*
108 * Force compression on the file using the defrag ioctl, could be
109 * different from prop_compress and takes precedence if set.
110 */
111 u8 defrag_compress;
112
113 /*
114 * Lock for counters and all fields used to determine if the inode is in
115 * the log or not (last_trans, last_sub_trans, last_log_commit,
116 * logged_trans), to access/update delalloc_bytes, new_delalloc_bytes,
117 * defrag_bytes, disk_i_size, outstanding_extents, csum_bytes and to
118 * update the VFS' inode number of bytes used.
119 */
120 spinlock_t lock;
121
122 /* the extent_tree has caches of all the extent mappings to disk */
123 struct extent_map_tree extent_tree;
124
125 /* the io_tree does range state (DIRTY, LOCKED etc) */
126 struct extent_io_tree io_tree;
127
128 /*
129 * Keep track of where the inode has extent items mapped in order to
130 * make sure the i_size adjustments are accurate. Not required when the
131 * filesystem is NO_HOLES, the status can't be set while mounted as
132 * it's a mkfs-time feature.
133 */
134 struct extent_io_tree *file_extent_tree;
135
136 /* held while logging the inode in tree-log.c */
137 struct mutex log_mutex;
138
139 /*
140 * Counters to keep track of the number of extent item's we may use due
141 * to delalloc and such. outstanding_extents is the number of extent
142 * items we think we'll end up using, and reserved_extents is the number
143 * of extent items we've reserved metadata for. Protected by 'lock'.
144 */
145 unsigned outstanding_extents;
146
147 /* used to order data wrt metadata */
148 spinlock_t ordered_tree_lock;
149 struct rb_root ordered_tree;
150 struct rb_node *ordered_tree_last;
151
152 /* list of all the delalloc inodes in the FS. There are times we need
153 * to write all the delalloc pages to disk, and this list is used
154 * to walk them all.
155 */
156 struct list_head delalloc_inodes;
157
158 /* node for the red-black tree that links inodes in subvolume root */
159 struct rb_node rb_node;
160
161 unsigned long runtime_flags;
162
163 /* full 64 bit generation number, struct vfs_inode doesn't have a big
164 * enough field for this.
165 */
166 u64 generation;
167
168 /*
169 * ID of the transaction handle that last modified this inode.
170 * Protected by 'lock'.
171 */
172 u64 last_trans;
173
174 /*
175 * ID of the transaction that last logged this inode.
176 * Protected by 'lock'.
177 */
178 u64 logged_trans;
179
180 /*
181 * Log transaction ID when this inode was last modified.
182 * Protected by 'lock'.
183 */
184 int last_sub_trans;
185
186 /* A local copy of root's last_log_commit. Protected by 'lock'. */
187 int last_log_commit;
188
189 union {
190 /*
191 * Total number of bytes pending delalloc, used by stat to
192 * calculate the real block usage of the file. This is used
193 * only for files. Protected by 'lock'.
194 */
195 u64 delalloc_bytes;
196 /*
197 * The lowest possible index of the next dir index key which
198 * points to an inode that needs to be logged.
199 * This is used only for directories.
200 * Use the helpers btrfs_get_first_dir_index_to_log() and
201 * btrfs_set_first_dir_index_to_log() to access this field.
202 */
203 u64 first_dir_index_to_log;
204 };
205
206 union {
207 /*
208 * Total number of bytes pending delalloc that fall within a file
209 * range that is either a hole or beyond EOF (and no prealloc extent
210 * exists in the range). This is always <= delalloc_bytes and this
211 * is used only for files. Protected by 'lock'.
212 */
213 u64 new_delalloc_bytes;
214 /*
215 * The offset of the last dir index key that was logged.
216 * This is used only for directories.
217 */
218 u64 last_dir_index_offset;
219 };
220
221 /*
222 * Total number of bytes pending defrag, used by stat to check whether
223 * it needs COW. Protected by 'lock'.
224 */
225 u64 defrag_bytes;
226
227 /*
228 * The size of the file stored in the metadata on disk. data=ordered
229 * means the in-memory i_size might be larger than the size on disk
230 * because not all the blocks are written yet. Protected by 'lock'.
231 */
232 u64 disk_i_size;
233
234 /*
235 * If this is a directory then index_cnt is the counter for the index
236 * number for new files that are created. For an empty directory, this
237 * must be initialized to BTRFS_DIR_START_INDEX.
238 */
239 u64 index_cnt;
240
241 /* Cache the directory index number to speed the dir/file remove */
242 u64 dir_index;
243
244 /* the fsync log has some corner cases that mean we have to check
245 * directories to see if any unlinks have been done before
246 * the directory was logged. See tree-log.c for all the
247 * details
248 */
249 u64 last_unlink_trans;
250
251 /*
252 * The id/generation of the last transaction where this inode was
253 * either the source or the destination of a clone/dedupe operation.
254 * Used when logging an inode to know if there are shared extents that
255 * need special care when logging checksum items, to avoid duplicate
256 * checksum items in a log (which can lead to a corruption where we end
257 * up with missing checksum ranges after log replay).
258 * Protected by the vfs inode lock.
259 */
260 u64 last_reflink_trans;
261
262 /*
263 * Number of bytes outstanding that are going to need csums. This is
264 * used in ENOSPC accounting. Protected by 'lock'.
265 */
266 u64 csum_bytes;
267
268 /* Backwards incompatible flags, lower half of inode_item::flags */
269 u32 flags;
270 /* Read-only compatibility flags, upper half of inode_item::flags */
271 u32 ro_flags;
272
273 struct btrfs_block_rsv block_rsv;
274
275 struct btrfs_delayed_node *delayed_node;
276
277 /* File creation time. */
278 u64 i_otime_sec;
279 u32 i_otime_nsec;
280
281 /* Hook into fs_info->delayed_iputs */
282 struct list_head delayed_iput;
283
284 struct rw_semaphore i_mmap_lock;
285 struct inode vfs_inode;
286};
287
288static inline u64 btrfs_get_first_dir_index_to_log(const struct btrfs_inode *inode)
289{
290 return READ_ONCE(inode->first_dir_index_to_log);
291}
292
293static inline void btrfs_set_first_dir_index_to_log(struct btrfs_inode *inode,
294 u64 index)
295{
296 WRITE_ONCE(inode->first_dir_index_to_log, index);
297}
298
299static inline struct btrfs_inode *BTRFS_I(const struct inode *inode)
300{
301 return container_of(inode, struct btrfs_inode, vfs_inode);
302}
303
304static inline unsigned long btrfs_inode_hash(u64 objectid,
305 const struct btrfs_root *root)
306{
307 u64 h = objectid ^ (root->root_key.objectid * GOLDEN_RATIO_PRIME);
308
309#if BITS_PER_LONG == 32
310 h = (h >> 32) ^ (h & 0xffffffff);
311#endif
312
313 return (unsigned long)h;
314}
315
316#if BITS_PER_LONG == 32
317
318/*
319 * On 32 bit systems the i_ino of struct inode is 32 bits (unsigned long), so
320 * we use the inode's location objectid which is a u64 to avoid truncation.
321 */
322static inline u64 btrfs_ino(const struct btrfs_inode *inode)
323{
324 u64 ino = inode->location.objectid;
325
326 /* type == BTRFS_ROOT_ITEM_KEY: subvol dir */
327 if (inode->location.type == BTRFS_ROOT_ITEM_KEY)
328 ino = inode->vfs_inode.i_ino;
329 return ino;
330}
331
332#else
333
334static inline u64 btrfs_ino(const struct btrfs_inode *inode)
335{
336 return inode->vfs_inode.i_ino;
337}
338
339#endif
340
341static inline void btrfs_i_size_write(struct btrfs_inode *inode, u64 size)
342{
343 i_size_write(inode: &inode->vfs_inode, i_size: size);
344 inode->disk_i_size = size;
345}
346
347static inline bool btrfs_is_free_space_inode(struct btrfs_inode *inode)
348{
349 return test_bit(BTRFS_INODE_FREE_SPACE_INODE, &inode->runtime_flags);
350}
351
352static inline bool is_data_inode(struct inode *inode)
353{
354 return btrfs_ino(inode: BTRFS_I(inode)) != BTRFS_BTREE_INODE_OBJECTID;
355}
356
357static inline void btrfs_mod_outstanding_extents(struct btrfs_inode *inode,
358 int mod)
359{
360 lockdep_assert_held(&inode->lock);
361 inode->outstanding_extents += mod;
362 if (btrfs_is_free_space_inode(inode))
363 return;
364 trace_btrfs_inode_mod_outstanding_extents(root: inode->root, ino: btrfs_ino(inode),
365 mod, outstanding: inode->outstanding_extents);
366}
367
368/*
369 * Called every time after doing a buffered, direct IO or memory mapped write.
370 *
371 * This is to ensure that if we write to a file that was previously fsynced in
372 * the current transaction, then try to fsync it again in the same transaction,
373 * we will know that there were changes in the file and that it needs to be
374 * logged.
375 */
376static inline void btrfs_set_inode_last_sub_trans(struct btrfs_inode *inode)
377{
378 spin_lock(lock: &inode->lock);
379 inode->last_sub_trans = inode->root->log_transid;
380 spin_unlock(lock: &inode->lock);
381}
382
383/*
384 * Should be called while holding the inode's VFS lock in exclusive mode or in a
385 * context where no one else can access the inode concurrently (during inode
386 * creation or when loading an inode from disk).
387 */
388static inline void btrfs_set_inode_full_sync(struct btrfs_inode *inode)
389{
390 set_bit(nr: BTRFS_INODE_NEEDS_FULL_SYNC, addr: &inode->runtime_flags);
391 /*
392 * The inode may have been part of a reflink operation in the last
393 * transaction that modified it, and then a fsync has reset the
394 * last_reflink_trans to avoid subsequent fsyncs in the same
395 * transaction to do unnecessary work. So update last_reflink_trans
396 * to the last_trans value (we have to be pessimistic and assume a
397 * reflink happened).
398 *
399 * The ->last_trans is protected by the inode's spinlock and we can
400 * have a concurrent ordered extent completion update it. Also set
401 * last_reflink_trans to ->last_trans only if the former is less than
402 * the later, because we can be called in a context where
403 * last_reflink_trans was set to the current transaction generation
404 * while ->last_trans was not yet updated in the current transaction,
405 * and therefore has a lower value.
406 */
407 spin_lock(lock: &inode->lock);
408 if (inode->last_reflink_trans < inode->last_trans)
409 inode->last_reflink_trans = inode->last_trans;
410 spin_unlock(lock: &inode->lock);
411}
412
413static inline bool btrfs_inode_in_log(struct btrfs_inode *inode, u64 generation)
414{
415 bool ret = false;
416
417 spin_lock(lock: &inode->lock);
418 if (inode->logged_trans == generation &&
419 inode->last_sub_trans <= inode->last_log_commit &&
420 inode->last_sub_trans <= btrfs_get_root_last_log_commit(root: inode->root))
421 ret = true;
422 spin_unlock(lock: &inode->lock);
423 return ret;
424}
425
426/*
427 * Check if the inode has flags compatible with compression
428 */
429static inline bool btrfs_inode_can_compress(const struct btrfs_inode *inode)
430{
431 if (inode->flags & BTRFS_INODE_NODATACOW ||
432 inode->flags & BTRFS_INODE_NODATASUM)
433 return false;
434 return true;
435}
436
437/* Array of bytes with variable length, hexadecimal format 0x1234 */
438#define CSUM_FMT "0x%*phN"
439#define CSUM_FMT_VALUE(size, bytes) size, bytes
440
441int btrfs_check_sector_csum(struct btrfs_fs_info *fs_info, struct page *page,
442 u32 pgoff, u8 *csum, const u8 * const csum_expected);
443bool btrfs_data_csum_ok(struct btrfs_bio *bbio, struct btrfs_device *dev,
444 u32 bio_offset, struct bio_vec *bv);
445noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
446 u64 *orig_start, u64 *orig_block_len,
447 u64 *ram_bytes, bool nowait, bool strict);
448
449void btrfs_del_delalloc_inode(struct btrfs_inode *inode);
450struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry);
451int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index);
452int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
453 struct btrfs_inode *dir, struct btrfs_inode *inode,
454 const struct fscrypt_str *name);
455int btrfs_add_link(struct btrfs_trans_handle *trans,
456 struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
457 const struct fscrypt_str *name, int add_backref, u64 index);
458int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry);
459int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
460 int front);
461
462int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context);
463int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
464 bool in_reclaim_context);
465int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
466 unsigned int extra_bits,
467 struct extent_state **cached_state);
468
469struct btrfs_new_inode_args {
470 /* Input */
471 struct inode *dir;
472 struct dentry *dentry;
473 struct inode *inode;
474 bool orphan;
475 bool subvol;
476
477 /* Output from btrfs_new_inode_prepare(), input to btrfs_create_new_inode(). */
478 struct posix_acl *default_acl;
479 struct posix_acl *acl;
480 struct fscrypt_name fname;
481};
482
483int btrfs_new_inode_prepare(struct btrfs_new_inode_args *args,
484 unsigned int *trans_num_items);
485int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
486 struct btrfs_new_inode_args *args);
487void btrfs_new_inode_args_destroy(struct btrfs_new_inode_args *args);
488struct inode *btrfs_new_subvol_inode(struct mnt_idmap *idmap,
489 struct inode *dir);
490 void btrfs_set_delalloc_extent(struct btrfs_inode *inode, struct extent_state *state,
491 u32 bits);
492void btrfs_clear_delalloc_extent(struct btrfs_inode *inode,
493 struct extent_state *state, u32 bits);
494void btrfs_merge_delalloc_extent(struct btrfs_inode *inode, struct extent_state *new,
495 struct extent_state *other);
496void btrfs_split_delalloc_extent(struct btrfs_inode *inode,
497 struct extent_state *orig, u64 split);
498void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end);
499vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf);
500void btrfs_evict_inode(struct inode *inode);
501struct inode *btrfs_alloc_inode(struct super_block *sb);
502void btrfs_destroy_inode(struct inode *inode);
503void btrfs_free_inode(struct inode *inode);
504int btrfs_drop_inode(struct inode *inode);
505int __init btrfs_init_cachep(void);
506void __cold btrfs_destroy_cachep(void);
507struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
508 struct btrfs_root *root, struct btrfs_path *path);
509struct inode *btrfs_iget(struct super_block *s, u64 ino, struct btrfs_root *root);
510struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
511 struct page *page, u64 start, u64 len);
512int btrfs_update_inode(struct btrfs_trans_handle *trans,
513 struct btrfs_inode *inode);
514int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
515 struct btrfs_inode *inode);
516int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct btrfs_inode *inode);
517int btrfs_orphan_cleanup(struct btrfs_root *root);
518int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size);
519void btrfs_add_delayed_iput(struct btrfs_inode *inode);
520void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info);
521int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info);
522int btrfs_prealloc_file_range(struct inode *inode, int mode,
523 u64 start, u64 num_bytes, u64 min_size,
524 loff_t actual_len, u64 *alloc_hint);
525int btrfs_prealloc_file_range_trans(struct inode *inode,
526 struct btrfs_trans_handle *trans, int mode,
527 u64 start, u64 num_bytes, u64 min_size,
528 loff_t actual_len, u64 *alloc_hint);
529int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page,
530 u64 start, u64 end, struct writeback_control *wbc);
531int btrfs_writepage_cow_fixup(struct page *page);
532int btrfs_encoded_io_compression_from_extent(struct btrfs_fs_info *fs_info,
533 int compress_type);
534int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
535 u64 file_offset, u64 disk_bytenr,
536 u64 disk_io_size,
537 struct page **pages);
538ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
539 struct btrfs_ioctl_encoded_io_args *encoded);
540ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
541 const struct btrfs_ioctl_encoded_io_args *encoded);
542
543ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter,
544 size_t done_before);
545struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter,
546 size_t done_before);
547
548extern const struct dentry_operations btrfs_dentry_operations;
549
550/* Inode locking type flags, by default the exclusive lock is taken. */
551enum btrfs_ilock_type {
552 ENUM_BIT(BTRFS_ILOCK_SHARED),
553 ENUM_BIT(BTRFS_ILOCK_TRY),
554 ENUM_BIT(BTRFS_ILOCK_MMAP),
555};
556
557int btrfs_inode_lock(struct btrfs_inode *inode, unsigned int ilock_flags);
558void btrfs_inode_unlock(struct btrfs_inode *inode, unsigned int ilock_flags);
559void btrfs_update_inode_bytes(struct btrfs_inode *inode, const u64 add_bytes,
560 const u64 del_bytes);
561void btrfs_assert_inode_range_clean(struct btrfs_inode *inode, u64 start, u64 end);
562
563#endif
564

source code of linux/fs/btrfs/btrfs_inode.h