xref: /linux/fs/btrfs/btrfs_inode.h (revision 257ca10c7317d4a424e48bb95d14ca53a1f1dd6f)
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/fscrypt.h>
12 #include <trace/events/btrfs.h>
13 #include "extent_map.h"
14 #include "extent_io.h"
15 #include "ordered-data.h"
16 #include "delayed-inode.h"
17 
18 /*
19  * Since we search a directory based on f_pos (struct dir_context::pos) we have
20  * to start at 2 since '.' and '..' have f_pos of 0 and 1 respectively, so
21  * everybody else has to start at 2 (see btrfs_real_readdir() and dir_emit_dots()).
22  */
23 #define BTRFS_DIR_START_INDEX 2
24 
25 /*
26  * ordered_data_close is set by truncate when a file that used
27  * to have good data has been truncated to zero.  When it is set
28  * the btrfs file release call will add this inode to the
29  * ordered operations list so that we make sure to flush out any
30  * new data the application may have written before commit.
31  */
32 enum {
33 	BTRFS_INODE_FLUSH_ON_CLOSE,
34 	BTRFS_INODE_DUMMY,
35 	BTRFS_INODE_IN_DEFRAG,
36 	BTRFS_INODE_HAS_ASYNC_EXTENT,
37 	 /*
38 	  * Always set under the VFS' inode lock, otherwise it can cause races
39 	  * during fsync (we start as a fast fsync and then end up in a full
40 	  * fsync racing with ordered extent completion).
41 	  */
42 	BTRFS_INODE_NEEDS_FULL_SYNC,
43 	BTRFS_INODE_COPY_EVERYTHING,
44 	BTRFS_INODE_IN_DELALLOC_LIST,
45 	BTRFS_INODE_HAS_PROPS,
46 	BTRFS_INODE_SNAPSHOT_FLUSH,
47 	/*
48 	 * Set and used when logging an inode and it serves to signal that an
49 	 * inode does not have xattrs, so subsequent fsyncs can avoid searching
50 	 * for xattrs to log. This bit must be cleared whenever a xattr is added
51 	 * to an inode.
52 	 */
53 	BTRFS_INODE_NO_XATTRS,
54 	/*
55 	 * Set when we are in a context where we need to start a transaction and
56 	 * have dirty pages with the respective file range locked. This is to
57 	 * ensure that when reserving space for the transaction, if we are low
58 	 * on available space and need to flush delalloc, we will not flush
59 	 * delalloc for this inode, because that could result in a deadlock (on
60 	 * the file range, inode's io_tree).
61 	 */
62 	BTRFS_INODE_NO_DELALLOC_FLUSH,
63 	/*
64 	 * Set when we are working on enabling verity for a file. Computing and
65 	 * writing the whole Merkle tree can take a while so we want to prevent
66 	 * races where two separate tasks attempt to simultaneously start verity
67 	 * on the same file.
68 	 */
69 	BTRFS_INODE_VERITY_IN_PROGRESS,
70 	/* Set when this inode is a free space inode. */
71 	BTRFS_INODE_FREE_SPACE_INODE,
72 	/* Set when there are no capabilities in XATTs for the inode. */
73 	BTRFS_INODE_NO_CAP_XATTR,
74 };
75 
76 /* in memory btrfs inode */
77 struct btrfs_inode {
78 	/* which subvolume this inode belongs to */
79 	struct btrfs_root *root;
80 
81 	/* key used to find this inode on disk.  This is used by the code
82 	 * to read in roots of subvolumes
83 	 */
84 	struct btrfs_key location;
85 
86 	/* Cached value of inode property 'compression'. */
87 	u8 prop_compress;
88 
89 	/*
90 	 * Force compression on the file using the defrag ioctl, could be
91 	 * different from prop_compress and takes precedence if set.
92 	 */
93 	u8 defrag_compress;
94 
95 	/*
96 	 * Lock for counters and all fields used to determine if the inode is in
97 	 * the log or not (last_trans, last_sub_trans, last_log_commit,
98 	 * logged_trans), to access/update delalloc_bytes, new_delalloc_bytes,
99 	 * defrag_bytes, disk_i_size, outstanding_extents, csum_bytes and to
100 	 * update the VFS' inode number of bytes used.
101 	 */
102 	spinlock_t lock;
103 
104 	/* the extent_tree has caches of all the extent mappings to disk */
105 	struct extent_map_tree extent_tree;
106 
107 	/* the io_tree does range state (DIRTY, LOCKED etc) */
108 	struct extent_io_tree io_tree;
109 
110 	/*
111 	 * Keep track of where the inode has extent items mapped in order to
112 	 * make sure the i_size adjustments are accurate. Not required when the
113 	 * filesystem is NO_HOLES, the status can't be set while mounted as
114 	 * it's a mkfs-time feature.
115 	 */
116 	struct extent_io_tree *file_extent_tree;
117 
118 	/* held while logging the inode in tree-log.c */
119 	struct mutex log_mutex;
120 
121 	/*
122 	 * Counters to keep track of the number of extent item's we may use due
123 	 * to delalloc and such.  outstanding_extents is the number of extent
124 	 * items we think we'll end up using, and reserved_extents is the number
125 	 * of extent items we've reserved metadata for. Protected by 'lock'.
126 	 */
127 	unsigned outstanding_extents;
128 
129 	/* used to order data wrt metadata */
130 	spinlock_t ordered_tree_lock;
131 	struct rb_root ordered_tree;
132 	struct rb_node *ordered_tree_last;
133 
134 	/* list of all the delalloc inodes in the FS.  There are times we need
135 	 * to write all the delalloc pages to disk, and this list is used
136 	 * to walk them all.
137 	 */
138 	struct list_head delalloc_inodes;
139 
140 	/* node for the red-black tree that links inodes in subvolume root */
141 	struct rb_node rb_node;
142 
143 	unsigned long runtime_flags;
144 
145 	/* full 64 bit generation number, struct vfs_inode doesn't have a big
146 	 * enough field for this.
147 	 */
148 	u64 generation;
149 
150 	/*
151 	 * ID of the transaction handle that last modified this inode.
152 	 * Protected by 'lock'.
153 	 */
154 	u64 last_trans;
155 
156 	/*
157 	 * ID of the transaction that last logged this inode.
158 	 * Protected by 'lock'.
159 	 */
160 	u64 logged_trans;
161 
162 	/*
163 	 * Log transaction ID when this inode was last modified.
164 	 * Protected by 'lock'.
165 	 */
166 	int last_sub_trans;
167 
168 	/* A local copy of root's last_log_commit. Protected by 'lock'. */
169 	int last_log_commit;
170 
171 	union {
172 		/*
173 		 * Total number of bytes pending delalloc, used by stat to
174 		 * calculate the real block usage of the file. This is used
175 		 * only for files. Protected by 'lock'.
176 		 */
177 		u64 delalloc_bytes;
178 		/*
179 		 * The lowest possible index of the next dir index key which
180 		 * points to an inode that needs to be logged.
181 		 * This is used only for directories.
182 		 * Use the helpers btrfs_get_first_dir_index_to_log() and
183 		 * btrfs_set_first_dir_index_to_log() to access this field.
184 		 */
185 		u64 first_dir_index_to_log;
186 	};
187 
188 	union {
189 		/*
190 		 * Total number of bytes pending delalloc that fall within a file
191 		 * range that is either a hole or beyond EOF (and no prealloc extent
192 		 * exists in the range). This is always <= delalloc_bytes and this
193 		 * is used only for files. Protected by 'lock'.
194 		 */
195 		u64 new_delalloc_bytes;
196 		/*
197 		 * The offset of the last dir index key that was logged.
198 		 * This is used only for directories.
199 		 */
200 		u64 last_dir_index_offset;
201 	};
202 
203 	/*
204 	 * Total number of bytes pending defrag, used by stat to check whether
205 	 * it needs COW. Protected by 'lock'.
206 	 */
207 	u64 defrag_bytes;
208 
209 	/*
210 	 * The size of the file stored in the metadata on disk.  data=ordered
211 	 * means the in-memory i_size might be larger than the size on disk
212 	 * because not all the blocks are written yet. Protected by 'lock'.
213 	 */
214 	u64 disk_i_size;
215 
216 	/*
217 	 * If this is a directory then index_cnt is the counter for the index
218 	 * number for new files that are created. For an empty directory, this
219 	 * must be initialized to BTRFS_DIR_START_INDEX.
220 	 */
221 	u64 index_cnt;
222 
223 	/* Cache the directory index number to speed the dir/file remove */
224 	u64 dir_index;
225 
226 	/* the fsync log has some corner cases that mean we have to check
227 	 * directories to see if any unlinks have been done before
228 	 * the directory was logged.  See tree-log.c for all the
229 	 * details
230 	 */
231 	u64 last_unlink_trans;
232 
233 	/*
234 	 * The id/generation of the last transaction where this inode was
235 	 * either the source or the destination of a clone/dedupe operation.
236 	 * Used when logging an inode to know if there are shared extents that
237 	 * need special care when logging checksum items, to avoid duplicate
238 	 * checksum items in a log (which can lead to a corruption where we end
239 	 * up with missing checksum ranges after log replay).
240 	 * Protected by the vfs inode lock.
241 	 */
242 	u64 last_reflink_trans;
243 
244 	/*
245 	 * Number of bytes outstanding that are going to need csums.  This is
246 	 * used in ENOSPC accounting. Protected by 'lock'.
247 	 */
248 	u64 csum_bytes;
249 
250 	/* Backwards incompatible flags, lower half of inode_item::flags  */
251 	u32 flags;
252 	/* Read-only compatibility flags, upper half of inode_item::flags */
253 	u32 ro_flags;
254 
255 	struct btrfs_block_rsv block_rsv;
256 
257 	struct btrfs_delayed_node *delayed_node;
258 
259 	/* File creation time. */
260 	u64 i_otime_sec;
261 	u32 i_otime_nsec;
262 
263 	/* Hook into fs_info->delayed_iputs */
264 	struct list_head delayed_iput;
265 
266 	struct rw_semaphore i_mmap_lock;
267 	struct inode vfs_inode;
268 };
269 
270 static inline u64 btrfs_get_first_dir_index_to_log(const struct btrfs_inode *inode)
271 {
272 	return READ_ONCE(inode->first_dir_index_to_log);
273 }
274 
275 static inline void btrfs_set_first_dir_index_to_log(struct btrfs_inode *inode,
276 						    u64 index)
277 {
278 	WRITE_ONCE(inode->first_dir_index_to_log, index);
279 }
280 
281 static inline struct btrfs_inode *BTRFS_I(const struct inode *inode)
282 {
283 	return container_of(inode, struct btrfs_inode, vfs_inode);
284 }
285 
286 static inline unsigned long btrfs_inode_hash(u64 objectid,
287 					     const struct btrfs_root *root)
288 {
289 	u64 h = objectid ^ (root->root_key.objectid * GOLDEN_RATIO_PRIME);
290 
291 #if BITS_PER_LONG == 32
292 	h = (h >> 32) ^ (h & 0xffffffff);
293 #endif
294 
295 	return (unsigned long)h;
296 }
297 
298 #if BITS_PER_LONG == 32
299 
300 /*
301  * On 32 bit systems the i_ino of struct inode is 32 bits (unsigned long), so
302  * we use the inode's location objectid which is a u64 to avoid truncation.
303  */
304 static inline u64 btrfs_ino(const struct btrfs_inode *inode)
305 {
306 	u64 ino = inode->location.objectid;
307 
308 	/* type == BTRFS_ROOT_ITEM_KEY: subvol dir */
309 	if (inode->location.type == BTRFS_ROOT_ITEM_KEY)
310 		ino = inode->vfs_inode.i_ino;
311 	return ino;
312 }
313 
314 #else
315 
316 static inline u64 btrfs_ino(const struct btrfs_inode *inode)
317 {
318 	return inode->vfs_inode.i_ino;
319 }
320 
321 #endif
322 
323 static inline void btrfs_i_size_write(struct btrfs_inode *inode, u64 size)
324 {
325 	i_size_write(&inode->vfs_inode, size);
326 	inode->disk_i_size = size;
327 }
328 
329 static inline bool btrfs_is_free_space_inode(struct btrfs_inode *inode)
330 {
331 	return test_bit(BTRFS_INODE_FREE_SPACE_INODE, &inode->runtime_flags);
332 }
333 
334 static inline bool is_data_inode(struct inode *inode)
335 {
336 	return btrfs_ino(BTRFS_I(inode)) != BTRFS_BTREE_INODE_OBJECTID;
337 }
338 
339 static inline void btrfs_mod_outstanding_extents(struct btrfs_inode *inode,
340 						 int mod)
341 {
342 	lockdep_assert_held(&inode->lock);
343 	inode->outstanding_extents += mod;
344 	if (btrfs_is_free_space_inode(inode))
345 		return;
346 	trace_btrfs_inode_mod_outstanding_extents(inode->root, btrfs_ino(inode),
347 						  mod, inode->outstanding_extents);
348 }
349 
350 /*
351  * Called every time after doing a buffered, direct IO or memory mapped write.
352  *
353  * This is to ensure that if we write to a file that was previously fsynced in
354  * the current transaction, then try to fsync it again in the same transaction,
355  * we will know that there were changes in the file and that it needs to be
356  * logged.
357  */
358 static inline void btrfs_set_inode_last_sub_trans(struct btrfs_inode *inode)
359 {
360 	spin_lock(&inode->lock);
361 	inode->last_sub_trans = inode->root->log_transid;
362 	spin_unlock(&inode->lock);
363 }
364 
365 /*
366  * Should be called while holding the inode's VFS lock in exclusive mode or in a
367  * context where no one else can access the inode concurrently (during inode
368  * creation or when loading an inode from disk).
369  */
370 static inline void btrfs_set_inode_full_sync(struct btrfs_inode *inode)
371 {
372 	set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
373 	/*
374 	 * The inode may have been part of a reflink operation in the last
375 	 * transaction that modified it, and then a fsync has reset the
376 	 * last_reflink_trans to avoid subsequent fsyncs in the same
377 	 * transaction to do unnecessary work. So update last_reflink_trans
378 	 * to the last_trans value (we have to be pessimistic and assume a
379 	 * reflink happened).
380 	 *
381 	 * The ->last_trans is protected by the inode's spinlock and we can
382 	 * have a concurrent ordered extent completion update it. Also set
383 	 * last_reflink_trans to ->last_trans only if the former is less than
384 	 * the later, because we can be called in a context where
385 	 * last_reflink_trans was set to the current transaction generation
386 	 * while ->last_trans was not yet updated in the current transaction,
387 	 * and therefore has a lower value.
388 	 */
389 	spin_lock(&inode->lock);
390 	if (inode->last_reflink_trans < inode->last_trans)
391 		inode->last_reflink_trans = inode->last_trans;
392 	spin_unlock(&inode->lock);
393 }
394 
395 static inline bool btrfs_inode_in_log(struct btrfs_inode *inode, u64 generation)
396 {
397 	bool ret = false;
398 
399 	spin_lock(&inode->lock);
400 	if (inode->logged_trans == generation &&
401 	    inode->last_sub_trans <= inode->last_log_commit &&
402 	    inode->last_sub_trans <= btrfs_get_root_last_log_commit(inode->root))
403 		ret = true;
404 	spin_unlock(&inode->lock);
405 	return ret;
406 }
407 
408 /*
409  * Check if the inode has flags compatible with compression
410  */
411 static inline bool btrfs_inode_can_compress(const struct btrfs_inode *inode)
412 {
413 	if (inode->flags & BTRFS_INODE_NODATACOW ||
414 	    inode->flags & BTRFS_INODE_NODATASUM)
415 		return false;
416 	return true;
417 }
418 
419 /* Array of bytes with variable length, hexadecimal format 0x1234 */
420 #define CSUM_FMT				"0x%*phN"
421 #define CSUM_FMT_VALUE(size, bytes)		size, bytes
422 
423 int btrfs_check_sector_csum(struct btrfs_fs_info *fs_info, struct page *page,
424 			    u32 pgoff, u8 *csum, const u8 * const csum_expected);
425 bool btrfs_data_csum_ok(struct btrfs_bio *bbio, struct btrfs_device *dev,
426 			u32 bio_offset, struct bio_vec *bv);
427 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
428 			      u64 *orig_start, u64 *orig_block_len,
429 			      u64 *ram_bytes, bool nowait, bool strict);
430 
431 void __btrfs_del_delalloc_inode(struct btrfs_root *root, struct btrfs_inode *inode);
432 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry);
433 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index);
434 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
435 		       struct btrfs_inode *dir, struct btrfs_inode *inode,
436 		       const struct fscrypt_str *name);
437 int btrfs_add_link(struct btrfs_trans_handle *trans,
438 		   struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
439 		   const struct fscrypt_str *name, int add_backref, u64 index);
440 int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry);
441 int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
442 			 int front);
443 
444 int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context);
445 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, long nr,
446 			       bool in_reclaim_context);
447 int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
448 			      unsigned int extra_bits,
449 			      struct extent_state **cached_state);
450 
451 struct btrfs_new_inode_args {
452 	/* Input */
453 	struct inode *dir;
454 	struct dentry *dentry;
455 	struct inode *inode;
456 	bool orphan;
457 	bool subvol;
458 
459 	/* Output from btrfs_new_inode_prepare(), input to btrfs_create_new_inode(). */
460 	struct posix_acl *default_acl;
461 	struct posix_acl *acl;
462 	struct fscrypt_name fname;
463 };
464 
465 int btrfs_new_inode_prepare(struct btrfs_new_inode_args *args,
466 			    unsigned int *trans_num_items);
467 int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
468 			   struct btrfs_new_inode_args *args);
469 void btrfs_new_inode_args_destroy(struct btrfs_new_inode_args *args);
470 struct inode *btrfs_new_subvol_inode(struct mnt_idmap *idmap,
471 				     struct inode *dir);
472  void btrfs_set_delalloc_extent(struct btrfs_inode *inode, struct extent_state *state,
473 			        u32 bits);
474 void btrfs_clear_delalloc_extent(struct btrfs_inode *inode,
475 				 struct extent_state *state, u32 bits);
476 void btrfs_merge_delalloc_extent(struct btrfs_inode *inode, struct extent_state *new,
477 				 struct extent_state *other);
478 void btrfs_split_delalloc_extent(struct btrfs_inode *inode,
479 				 struct extent_state *orig, u64 split);
480 void btrfs_set_range_writeback(struct btrfs_inode *inode, u64 start, u64 end);
481 vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf);
482 void btrfs_evict_inode(struct inode *inode);
483 struct inode *btrfs_alloc_inode(struct super_block *sb);
484 void btrfs_destroy_inode(struct inode *inode);
485 void btrfs_free_inode(struct inode *inode);
486 int btrfs_drop_inode(struct inode *inode);
487 int __init btrfs_init_cachep(void);
488 void __cold btrfs_destroy_cachep(void);
489 struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
490 			      struct btrfs_root *root, struct btrfs_path *path);
491 struct inode *btrfs_iget(struct super_block *s, u64 ino, struct btrfs_root *root);
492 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
493 				    struct page *page, size_t pg_offset,
494 				    u64 start, u64 len);
495 int btrfs_update_inode(struct btrfs_trans_handle *trans,
496 		       struct btrfs_inode *inode);
497 int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
498 				struct btrfs_inode *inode);
499 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct btrfs_inode *inode);
500 int btrfs_orphan_cleanup(struct btrfs_root *root);
501 int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size);
502 void btrfs_add_delayed_iput(struct btrfs_inode *inode);
503 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info);
504 int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info);
505 int btrfs_prealloc_file_range(struct inode *inode, int mode,
506 			      u64 start, u64 num_bytes, u64 min_size,
507 			      loff_t actual_len, u64 *alloc_hint);
508 int btrfs_prealloc_file_range_trans(struct inode *inode,
509 				    struct btrfs_trans_handle *trans, int mode,
510 				    u64 start, u64 num_bytes, u64 min_size,
511 				    loff_t actual_len, u64 *alloc_hint);
512 int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page,
513 			     u64 start, u64 end, struct writeback_control *wbc);
514 int btrfs_writepage_cow_fixup(struct page *page);
515 int btrfs_encoded_io_compression_from_extent(struct btrfs_fs_info *fs_info,
516 					     int compress_type);
517 int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode,
518 					  u64 file_offset, u64 disk_bytenr,
519 					  u64 disk_io_size,
520 					  struct page **pages);
521 ssize_t btrfs_encoded_read(struct kiocb *iocb, struct iov_iter *iter,
522 			   struct btrfs_ioctl_encoded_io_args *encoded);
523 ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
524 			       const struct btrfs_ioctl_encoded_io_args *encoded);
525 
526 ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter,
527 		       size_t done_before);
528 struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter,
529 				  size_t done_before);
530 
531 extern const struct dentry_operations btrfs_dentry_operations;
532 
533 /* Inode locking type flags, by default the exclusive lock is taken. */
534 enum btrfs_ilock_type {
535 	ENUM_BIT(BTRFS_ILOCK_SHARED),
536 	ENUM_BIT(BTRFS_ILOCK_TRY),
537 	ENUM_BIT(BTRFS_ILOCK_MMAP),
538 };
539 
540 int btrfs_inode_lock(struct btrfs_inode *inode, unsigned int ilock_flags);
541 void btrfs_inode_unlock(struct btrfs_inode *inode, unsigned int ilock_flags);
542 void btrfs_update_inode_bytes(struct btrfs_inode *inode, const u64 add_bytes,
543 			      const u64 del_bytes);
544 void btrfs_assert_inode_range_clean(struct btrfs_inode *inode, u64 start, u64 end);
545 
546 #endif
547