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 "extent_map.h"
12 #include "extent_io.h"
13 #include "ordered-data.h"
14 #include "delayed-inode.h"
15 
16 /*
17  * Since we search a directory based on f_pos (struct dir_context::pos) we have
18  * to start at 2 since '.' and '..' have f_pos of 0 and 1 respectively, so
19  * everybody else has to start at 2 (see btrfs_real_readdir() and dir_emit_dots()).
20  */
21 #define BTRFS_DIR_START_INDEX 2
22 
23 /*
24  * ordered_data_close is set by truncate when a file that used
25  * to have good data has been truncated to zero.  When it is set
26  * the btrfs file release call will add this inode to the
27  * ordered operations list so that we make sure to flush out any
28  * new data the application may have written before commit.
29  */
30 enum {
31 	BTRFS_INODE_FLUSH_ON_CLOSE,
32 	BTRFS_INODE_DUMMY,
33 	BTRFS_INODE_IN_DEFRAG,
34 	BTRFS_INODE_HAS_ASYNC_EXTENT,
35 	 /*
36 	  * Always set under the VFS' inode lock, otherwise it can cause races
37 	  * during fsync (we start as a fast fsync and then end up in a full
38 	  * fsync racing with ordered extent completion).
39 	  */
40 	BTRFS_INODE_NEEDS_FULL_SYNC,
41 	BTRFS_INODE_COPY_EVERYTHING,
42 	BTRFS_INODE_IN_DELALLOC_LIST,
43 	BTRFS_INODE_HAS_PROPS,
44 	BTRFS_INODE_SNAPSHOT_FLUSH,
45 	/*
46 	 * Set and used when logging an inode and it serves to signal that an
47 	 * inode does not have xattrs, so subsequent fsyncs can avoid searching
48 	 * for xattrs to log. This bit must be cleared whenever a xattr is added
49 	 * to an inode.
50 	 */
51 	BTRFS_INODE_NO_XATTRS,
52 	/*
53 	 * Set when we are in a context where we need to start a transaction and
54 	 * have dirty pages with the respective file range locked. This is to
55 	 * ensure that when reserving space for the transaction, if we are low
56 	 * on available space and need to flush delalloc, we will not flush
57 	 * delalloc for this inode, because that could result in a deadlock (on
58 	 * the file range, inode's io_tree).
59 	 */
60 	BTRFS_INODE_NO_DELALLOC_FLUSH,
61 	/*
62 	 * Set when we are working on enabling verity for a file. Computing and
63 	 * writing the whole Merkle tree can take a while so we want to prevent
64 	 * races where two separate tasks attempt to simultaneously start verity
65 	 * on the same file.
66 	 */
67 	BTRFS_INODE_VERITY_IN_PROGRESS,
68 };
69 
70 /* in memory btrfs inode */
71 struct btrfs_inode {
72 	/* which subvolume this inode belongs to */
73 	struct btrfs_root *root;
74 
75 	/* key used to find this inode on disk.  This is used by the code
76 	 * to read in roots of subvolumes
77 	 */
78 	struct btrfs_key location;
79 
80 	/*
81 	 * Lock for counters and all fields used to determine if the inode is in
82 	 * the log or not (last_trans, last_sub_trans, last_log_commit,
83 	 * logged_trans), to access/update new_delalloc_bytes and to update the
84 	 * VFS' inode number of bytes used.
85 	 */
86 	spinlock_t lock;
87 
88 	/* the extent_tree has caches of all the extent mappings to disk */
89 	struct extent_map_tree extent_tree;
90 
91 	/* the io_tree does range state (DIRTY, LOCKED etc) */
92 	struct extent_io_tree io_tree;
93 
94 	/* special utility tree used to record which mirrors have already been
95 	 * tried when checksums fail for a given block
96 	 */
97 	struct extent_io_tree io_failure_tree;
98 
99 	/*
100 	 * Keep track of where the inode has extent items mapped in order to
101 	 * make sure the i_size adjustments are accurate
102 	 */
103 	struct extent_io_tree file_extent_tree;
104 
105 	/* held while logging the inode in tree-log.c */
106 	struct mutex log_mutex;
107 
108 	/* used to order data wrt metadata */
109 	struct btrfs_ordered_inode_tree ordered_tree;
110 
111 	/* list of all the delalloc inodes in the FS.  There are times we need
112 	 * to write all the delalloc pages to disk, and this list is used
113 	 * to walk them all.
114 	 */
115 	struct list_head delalloc_inodes;
116 
117 	/* node for the red-black tree that links inodes in subvolume root */
118 	struct rb_node rb_node;
119 
120 	unsigned long runtime_flags;
121 
122 	/* Keep track of who's O_SYNC/fsyncing currently */
123 	atomic_t sync_writers;
124 
125 	/* full 64 bit generation number, struct vfs_inode doesn't have a big
126 	 * enough field for this.
127 	 */
128 	u64 generation;
129 
130 	/*
131 	 * transid of the trans_handle that last modified this inode
132 	 */
133 	u64 last_trans;
134 
135 	/*
136 	 * transid that last logged this inode
137 	 */
138 	u64 logged_trans;
139 
140 	/*
141 	 * log transid when this inode was last modified
142 	 */
143 	int last_sub_trans;
144 
145 	/* a local copy of root's last_log_commit */
146 	int last_log_commit;
147 
148 	/*
149 	 * Total number of bytes pending delalloc, used by stat to calculate the
150 	 * real block usage of the file. This is used only for files.
151 	 */
152 	u64 delalloc_bytes;
153 
154 	union {
155 		/*
156 		 * Total number of bytes pending delalloc that fall within a file
157 		 * range that is either a hole or beyond EOF (and no prealloc extent
158 		 * exists in the range). This is always <= delalloc_bytes and this
159 		 * is used only for files.
160 		 */
161 		u64 new_delalloc_bytes;
162 		/*
163 		 * The offset of the last dir index key that was logged.
164 		 * This is used only for directories.
165 		 */
166 		u64 last_dir_index_offset;
167 	};
168 
169 	/*
170 	 * total number of bytes pending defrag, used by stat to check whether
171 	 * it needs COW.
172 	 */
173 	u64 defrag_bytes;
174 
175 	/*
176 	 * the size of the file stored in the metadata on disk.  data=ordered
177 	 * means the in-memory i_size might be larger than the size on disk
178 	 * because not all the blocks are written yet.
179 	 */
180 	u64 disk_i_size;
181 
182 	/*
183 	 * If this is a directory then index_cnt is the counter for the index
184 	 * number for new files that are created. For an empty directory, this
185 	 * must be initialized to BTRFS_DIR_START_INDEX.
186 	 */
187 	u64 index_cnt;
188 
189 	/* Cache the directory index number to speed the dir/file remove */
190 	u64 dir_index;
191 
192 	/* the fsync log has some corner cases that mean we have to check
193 	 * directories to see if any unlinks have been done before
194 	 * the directory was logged.  See tree-log.c for all the
195 	 * details
196 	 */
197 	u64 last_unlink_trans;
198 
199 	/*
200 	 * The id/generation of the last transaction where this inode was
201 	 * either the source or the destination of a clone/dedupe operation.
202 	 * Used when logging an inode to know if there are shared extents that
203 	 * need special care when logging checksum items, to avoid duplicate
204 	 * checksum items in a log (which can lead to a corruption where we end
205 	 * up with missing checksum ranges after log replay).
206 	 * Protected by the vfs inode lock.
207 	 */
208 	u64 last_reflink_trans;
209 
210 	/*
211 	 * Number of bytes outstanding that are going to need csums.  This is
212 	 * used in ENOSPC accounting.
213 	 */
214 	u64 csum_bytes;
215 
216 	/* Backwards incompatible flags, lower half of inode_item::flags  */
217 	u32 flags;
218 	/* Read-only compatibility flags, upper half of inode_item::flags */
219 	u32 ro_flags;
220 
221 	/*
222 	 * Counters to keep track of the number of extent item's we may use due
223 	 * to delalloc and such.  outstanding_extents is the number of extent
224 	 * items we think we'll end up using, and reserved_extents is the number
225 	 * of extent items we've reserved metadata for.
226 	 */
227 	unsigned outstanding_extents;
228 
229 	struct btrfs_block_rsv block_rsv;
230 
231 	/*
232 	 * Cached values of inode properties
233 	 */
234 	unsigned prop_compress;		/* per-file compression algorithm */
235 	/*
236 	 * Force compression on the file using the defrag ioctl, could be
237 	 * different from prop_compress and takes precedence if set
238 	 */
239 	unsigned defrag_compress;
240 
241 	struct btrfs_delayed_node *delayed_node;
242 
243 	/* File creation time. */
244 	struct timespec64 i_otime;
245 
246 	/* Hook into fs_info->delayed_iputs */
247 	struct list_head delayed_iput;
248 
249 	struct rw_semaphore i_mmap_lock;
250 	struct inode vfs_inode;
251 };
252 
btrfs_inode_sectorsize(const struct btrfs_inode * inode)253 static inline u32 btrfs_inode_sectorsize(const struct btrfs_inode *inode)
254 {
255 	return inode->root->fs_info->sectorsize;
256 }
257 
BTRFS_I(const struct inode * inode)258 static inline struct btrfs_inode *BTRFS_I(const struct inode *inode)
259 {
260 	return container_of(inode, struct btrfs_inode, vfs_inode);
261 }
262 
btrfs_inode_hash(u64 objectid,const struct btrfs_root * root)263 static inline unsigned long btrfs_inode_hash(u64 objectid,
264 					     const struct btrfs_root *root)
265 {
266 	u64 h = objectid ^ (root->root_key.objectid * GOLDEN_RATIO_PRIME);
267 
268 #if BITS_PER_LONG == 32
269 	h = (h >> 32) ^ (h & 0xffffffff);
270 #endif
271 
272 	return (unsigned long)h;
273 }
274 
btrfs_insert_inode_hash(struct inode * inode)275 static inline void btrfs_insert_inode_hash(struct inode *inode)
276 {
277 	unsigned long h = btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root);
278 
279 	__insert_inode_hash(inode, h);
280 }
281 
btrfs_ino(const struct btrfs_inode * inode)282 static inline u64 btrfs_ino(const struct btrfs_inode *inode)
283 {
284 	u64 ino = inode->location.objectid;
285 
286 	/*
287 	 * !ino: btree_inode
288 	 * type == BTRFS_ROOT_ITEM_KEY: subvol dir
289 	 */
290 	if (!ino || inode->location.type == BTRFS_ROOT_ITEM_KEY)
291 		ino = inode->vfs_inode.i_ino;
292 	return ino;
293 }
294 
btrfs_i_size_write(struct btrfs_inode * inode,u64 size)295 static inline void btrfs_i_size_write(struct btrfs_inode *inode, u64 size)
296 {
297 	i_size_write(&inode->vfs_inode, size);
298 	inode->disk_i_size = size;
299 }
300 
btrfs_is_free_space_inode(struct btrfs_inode * inode)301 static inline bool btrfs_is_free_space_inode(struct btrfs_inode *inode)
302 {
303 	struct btrfs_root *root = inode->root;
304 
305 	if (root == root->fs_info->tree_root &&
306 	    btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)
307 		return true;
308 	if (inode->location.objectid == BTRFS_FREE_INO_OBJECTID)
309 		return true;
310 	return false;
311 }
312 
is_data_inode(struct inode * inode)313 static inline bool is_data_inode(struct inode *inode)
314 {
315 	return btrfs_ino(BTRFS_I(inode)) != BTRFS_BTREE_INODE_OBJECTID;
316 }
317 
btrfs_mod_outstanding_extents(struct btrfs_inode * inode,int mod)318 static inline void btrfs_mod_outstanding_extents(struct btrfs_inode *inode,
319 						 int mod)
320 {
321 	lockdep_assert_held(&inode->lock);
322 	inode->outstanding_extents += mod;
323 	if (btrfs_is_free_space_inode(inode))
324 		return;
325 	trace_btrfs_inode_mod_outstanding_extents(inode->root, btrfs_ino(inode),
326 						  mod);
327 }
328 
329 /*
330  * Called every time after doing a buffered, direct IO or memory mapped write.
331  *
332  * This is to ensure that if we write to a file that was previously fsynced in
333  * the current transaction, then try to fsync it again in the same transaction,
334  * we will know that there were changes in the file and that it needs to be
335  * logged.
336  */
btrfs_set_inode_last_sub_trans(struct btrfs_inode * inode)337 static inline void btrfs_set_inode_last_sub_trans(struct btrfs_inode *inode)
338 {
339 	spin_lock(&inode->lock);
340 	inode->last_sub_trans = inode->root->log_transid;
341 	spin_unlock(&inode->lock);
342 }
343 
344 /*
345  * Should be called while holding the inode's VFS lock in exclusive mode or in a
346  * context where no one else can access the inode concurrently (during inode
347  * creation or when loading an inode from disk).
348  */
btrfs_set_inode_full_sync(struct btrfs_inode * inode)349 static inline void btrfs_set_inode_full_sync(struct btrfs_inode *inode)
350 {
351 	set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
352 	/*
353 	 * The inode may have been part of a reflink operation in the last
354 	 * transaction that modified it, and then a fsync has reset the
355 	 * last_reflink_trans to avoid subsequent fsyncs in the same
356 	 * transaction to do unnecessary work. So update last_reflink_trans
357 	 * to the last_trans value (we have to be pessimistic and assume a
358 	 * reflink happened).
359 	 *
360 	 * The ->last_trans is protected by the inode's spinlock and we can
361 	 * have a concurrent ordered extent completion update it. Also set
362 	 * last_reflink_trans to ->last_trans only if the former is less than
363 	 * the later, because we can be called in a context where
364 	 * last_reflink_trans was set to the current transaction generation
365 	 * while ->last_trans was not yet updated in the current transaction,
366 	 * and therefore has a lower value.
367 	 */
368 	spin_lock(&inode->lock);
369 	if (inode->last_reflink_trans < inode->last_trans)
370 		inode->last_reflink_trans = inode->last_trans;
371 	spin_unlock(&inode->lock);
372 }
373 
btrfs_inode_in_log(struct btrfs_inode * inode,u64 generation)374 static inline bool btrfs_inode_in_log(struct btrfs_inode *inode, u64 generation)
375 {
376 	bool ret = false;
377 
378 	spin_lock(&inode->lock);
379 	if (inode->logged_trans == generation &&
380 	    inode->last_sub_trans <= inode->last_log_commit &&
381 	    inode->last_sub_trans <= inode->root->last_log_commit)
382 		ret = true;
383 	spin_unlock(&inode->lock);
384 	return ret;
385 }
386 
387 /*
388  * Check if the inode has flags compatible with compression
389  */
btrfs_inode_can_compress(const struct btrfs_inode * inode)390 static inline bool btrfs_inode_can_compress(const struct btrfs_inode *inode)
391 {
392 	if (inode->flags & BTRFS_INODE_NODATACOW ||
393 	    inode->flags & BTRFS_INODE_NODATASUM)
394 		return false;
395 	return true;
396 }
397 
398 /*
399  * btrfs_inode_item stores flags in a u64, btrfs_inode stores them in two
400  * separate u32s. These two functions convert between the two representations.
401  */
btrfs_inode_combine_flags(u32 flags,u32 ro_flags)402 static inline u64 btrfs_inode_combine_flags(u32 flags, u32 ro_flags)
403 {
404 	return (flags | ((u64)ro_flags << 32));
405 }
406 
btrfs_inode_split_flags(u64 inode_item_flags,u32 * flags,u32 * ro_flags)407 static inline void btrfs_inode_split_flags(u64 inode_item_flags,
408 					   u32 *flags, u32 *ro_flags)
409 {
410 	*flags = (u32)inode_item_flags;
411 	*ro_flags = (u32)(inode_item_flags >> 32);
412 }
413 
414 /* Array of bytes with variable length, hexadecimal format 0x1234 */
415 #define CSUM_FMT				"0x%*phN"
416 #define CSUM_FMT_VALUE(size, bytes)		size, bytes
417 
btrfs_print_data_csum_error(struct btrfs_inode * inode,u64 logical_start,u8 * csum,u8 * csum_expected,int mirror_num)418 static inline void btrfs_print_data_csum_error(struct btrfs_inode *inode,
419 		u64 logical_start, u8 *csum, u8 *csum_expected, int mirror_num)
420 {
421 	struct btrfs_root *root = inode->root;
422 	const u32 csum_size = root->fs_info->csum_size;
423 
424 	/* Output minus objectid, which is more meaningful */
425 	if (root->root_key.objectid >= BTRFS_LAST_FREE_OBJECTID)
426 		btrfs_warn_rl(root->fs_info,
427 "csum failed root %lld ino %lld off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
428 			root->root_key.objectid, btrfs_ino(inode),
429 			logical_start,
430 			CSUM_FMT_VALUE(csum_size, csum),
431 			CSUM_FMT_VALUE(csum_size, csum_expected),
432 			mirror_num);
433 	else
434 		btrfs_warn_rl(root->fs_info,
435 "csum failed root %llu ino %llu off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
436 			root->root_key.objectid, btrfs_ino(inode),
437 			logical_start,
438 			CSUM_FMT_VALUE(csum_size, csum),
439 			CSUM_FMT_VALUE(csum_size, csum_expected),
440 			mirror_num);
441 }
442 
443 #endif
444