xref: /linux/fs/ext4/ext4_jbd2.h (revision 662fa3d6099374c4615bf64d06895e3573b935b2)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * ext4_jbd2.h
4  *
5  * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
6  *
7  * Copyright 1998--1999 Red Hat corp --- All Rights Reserved
8  *
9  * Ext4-specific journaling extensions.
10  */
11 
12 #ifndef _EXT4_JBD2_H
13 #define _EXT4_JBD2_H
14 
15 #include <linux/fs.h>
16 #include <linux/jbd2.h>
17 #include "ext4.h"
18 
19 #define EXT4_JOURNAL(inode)	(EXT4_SB((inode)->i_sb)->s_journal)
20 
21 /* Define the number of blocks we need to account to a transaction to
22  * modify one block of data.
23  *
24  * We may have to touch one inode, one bitmap buffer, up to three
25  * indirection blocks, the group and superblock summaries, and the data
26  * block to complete the transaction.
27  *
28  * For extents-enabled fs we may have to allocate and modify up to
29  * 5 levels of tree, data block (for each of these we need bitmap + group
30  * summaries), root which is stored in the inode, sb
31  */
32 
33 #define EXT4_SINGLEDATA_TRANS_BLOCKS(sb)				\
34 	(ext4_has_feature_extents(sb) ? 20U : 8U)
35 
36 /* Extended attribute operations touch at most two data buffers,
37  * two bitmap buffers, and two group summaries, in addition to the inode
38  * and the superblock, which are already accounted for. */
39 
40 #define EXT4_XATTR_TRANS_BLOCKS		6U
41 
42 /* Define the minimum size for a transaction which modifies data.  This
43  * needs to take into account the fact that we may end up modifying two
44  * quota files too (one for the group, one for the user quota).  The
45  * superblock only gets updated once, of course, so don't bother
46  * counting that again for the quota updates. */
47 
48 #define EXT4_DATA_TRANS_BLOCKS(sb)	(EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + \
49 					 EXT4_XATTR_TRANS_BLOCKS - 2 + \
50 					 EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
51 
52 /*
53  * Define the number of metadata blocks we need to account to modify data.
54  *
55  * This include super block, inode block, quota blocks and xattr blocks
56  */
57 #define EXT4_META_TRANS_BLOCKS(sb)	(EXT4_XATTR_TRANS_BLOCKS + \
58 					EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
59 
60 /* Define an arbitrary limit for the amount of data we will anticipate
61  * writing to any given transaction.  For unbounded transactions such as
62  * write(2) and truncate(2) we can write more than this, but we always
63  * start off at the maximum transaction size and grow the transaction
64  * optimistically as we go. */
65 
66 #define EXT4_MAX_TRANS_DATA		64U
67 
68 /* We break up a large truncate or write transaction once the handle's
69  * buffer credits gets this low, we need either to extend the
70  * transaction or to start a new one.  Reserve enough space here for
71  * inode, bitmap, superblock, group and indirection updates for at least
72  * one block, plus two quota updates.  Quota allocations are not
73  * needed. */
74 
75 #define EXT4_RESERVE_TRANS_BLOCKS	12U
76 
77 /*
78  * Number of credits needed if we need to insert an entry into a
79  * directory.  For each new index block, we need 4 blocks (old index
80  * block, new index block, bitmap block, bg summary).  For normal
81  * htree directories there are 2 levels; if the largedir feature
82  * enabled it's 3 levels.
83  */
84 #define EXT4_INDEX_EXTRA_TRANS_BLOCKS	12U
85 
86 #ifdef CONFIG_QUOTA
87 /* Amount of blocks needed for quota update - we know that the structure was
88  * allocated so we need to update only data block */
89 #define EXT4_QUOTA_TRANS_BLOCKS(sb) ((ext4_quota_capable(sb)) ? 1 : 0)
90 /* Amount of blocks needed for quota insert/delete - we do some block writes
91  * but inode, sb and group updates are done only once */
92 #define EXT4_QUOTA_INIT_BLOCKS(sb) ((ext4_quota_capable(sb)) ?\
93 		(DQUOT_INIT_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
94 		 +3+DQUOT_INIT_REWRITE) : 0)
95 
96 #define EXT4_QUOTA_DEL_BLOCKS(sb) ((ext4_quota_capable(sb)) ?\
97 		(DQUOT_DEL_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
98 		 +3+DQUOT_DEL_REWRITE) : 0)
99 #else
100 #define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
101 #define EXT4_QUOTA_INIT_BLOCKS(sb) 0
102 #define EXT4_QUOTA_DEL_BLOCKS(sb) 0
103 #endif
104 #define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb))
105 #define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
106 #define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
107 
108 /*
109  * Ext4 handle operation types -- for logging purposes
110  */
111 #define EXT4_HT_MISC             0
112 #define EXT4_HT_INODE            1
113 #define EXT4_HT_WRITE_PAGE       2
114 #define EXT4_HT_MAP_BLOCKS       3
115 #define EXT4_HT_DIR              4
116 #define EXT4_HT_TRUNCATE         5
117 #define EXT4_HT_QUOTA            6
118 #define EXT4_HT_RESIZE           7
119 #define EXT4_HT_MIGRATE          8
120 #define EXT4_HT_MOVE_EXTENTS     9
121 #define EXT4_HT_XATTR           10
122 #define EXT4_HT_EXT_CONVERT     11
123 #define EXT4_HT_MAX             12
124 
125 /**
126  *   struct ext4_journal_cb_entry - Base structure for callback information.
127  *
128  *   This struct is a 'seed' structure for a using with your own callback
129  *   structs. If you are using callbacks you must allocate one of these
130  *   or another struct of your own definition which has this struct
131  *   as it's first element and pass it to ext4_journal_callback_add().
132  */
133 struct ext4_journal_cb_entry {
134 	/* list information for other callbacks attached to the same handle */
135 	struct list_head jce_list;
136 
137 	/*  Function to call with this callback structure */
138 	void (*jce_func)(struct super_block *sb,
139 			 struct ext4_journal_cb_entry *jce, int error);
140 
141 	/* user data goes here */
142 };
143 
144 /**
145  * ext4_journal_callback_add: add a function to call after transaction commit
146  * @handle: active journal transaction handle to register callback on
147  * @func: callback function to call after the transaction has committed:
148  *        @sb: superblock of current filesystem for transaction
149  *        @jce: returned journal callback data
150  *        @rc: journal state at commit (0 = transaction committed properly)
151  * @jce: journal callback data (internal and function private data struct)
152  *
153  * The registered function will be called in the context of the journal thread
154  * after the transaction for which the handle was created has completed.
155  *
156  * No locks are held when the callback function is called, so it is safe to
157  * call blocking functions from within the callback, but the callback should
158  * not block or run for too long, or the filesystem will be blocked waiting for
159  * the next transaction to commit. No journaling functions can be used, or
160  * there is a risk of deadlock.
161  *
162  * There is no guaranteed calling order of multiple registered callbacks on
163  * the same transaction.
164  */
165 static inline void _ext4_journal_callback_add(handle_t *handle,
166 			struct ext4_journal_cb_entry *jce)
167 {
168 	/* Add the jce to transaction's private list */
169 	list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list);
170 }
171 
172 static inline void ext4_journal_callback_add(handle_t *handle,
173 			void (*func)(struct super_block *sb,
174 				     struct ext4_journal_cb_entry *jce,
175 				     int rc),
176 			struct ext4_journal_cb_entry *jce)
177 {
178 	struct ext4_sb_info *sbi =
179 			EXT4_SB(handle->h_transaction->t_journal->j_private);
180 
181 	/* Add the jce to transaction's private list */
182 	jce->jce_func = func;
183 	spin_lock(&sbi->s_md_lock);
184 	_ext4_journal_callback_add(handle, jce);
185 	spin_unlock(&sbi->s_md_lock);
186 }
187 
188 
189 /**
190  * ext4_journal_callback_del: delete a registered callback
191  * @handle: active journal transaction handle on which callback was registered
192  * @jce: registered journal callback entry to unregister
193  * Return true if object was successfully removed
194  */
195 static inline bool ext4_journal_callback_try_del(handle_t *handle,
196 					     struct ext4_journal_cb_entry *jce)
197 {
198 	bool deleted;
199 	struct ext4_sb_info *sbi =
200 			EXT4_SB(handle->h_transaction->t_journal->j_private);
201 
202 	spin_lock(&sbi->s_md_lock);
203 	deleted = !list_empty(&jce->jce_list);
204 	list_del_init(&jce->jce_list);
205 	spin_unlock(&sbi->s_md_lock);
206 	return deleted;
207 }
208 
209 int
210 ext4_mark_iloc_dirty(handle_t *handle,
211 		     struct inode *inode,
212 		     struct ext4_iloc *iloc);
213 
214 /*
215  * On success, We end up with an outstanding reference count against
216  * iloc->bh.  This _must_ be cleaned up later.
217  */
218 
219 int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
220 			struct ext4_iloc *iloc);
221 
222 #define ext4_mark_inode_dirty(__h, __i)					\
223 		__ext4_mark_inode_dirty((__h), (__i), __func__, __LINE__)
224 int __ext4_mark_inode_dirty(handle_t *handle, struct inode *inode,
225 				const char *func, unsigned int line);
226 
227 int ext4_expand_extra_isize(struct inode *inode,
228 			    unsigned int new_extra_isize,
229 			    struct ext4_iloc *iloc);
230 /*
231  * Wrapper functions with which ext4 calls into JBD.
232  */
233 int __ext4_journal_get_write_access(const char *where, unsigned int line,
234 				    handle_t *handle, struct buffer_head *bh);
235 
236 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
237 		  int is_metadata, struct inode *inode,
238 		  struct buffer_head *bh, ext4_fsblk_t blocknr);
239 
240 int __ext4_journal_get_create_access(const char *where, unsigned int line,
241 				handle_t *handle, struct buffer_head *bh);
242 
243 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
244 				 handle_t *handle, struct inode *inode,
245 				 struct buffer_head *bh);
246 
247 #define ext4_journal_get_write_access(handle, bh) \
248 	__ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
249 #define ext4_forget(handle, is_metadata, inode, bh, block_nr) \
250 	__ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \
251 		      (bh), (block_nr))
252 #define ext4_journal_get_create_access(handle, bh) \
253 	__ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh))
254 #define ext4_handle_dirty_metadata(handle, inode, bh) \
255 	__ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
256 				     (bh))
257 
258 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
259 				  int type, int blocks, int rsv_blocks,
260 				  int revoke_creds);
261 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
262 
263 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
264 
265 /* Note:  Do not use this for NULL handles.  This is only to determine if
266  * a properly allocated handle is using a journal or not. */
267 static inline int ext4_handle_valid(handle_t *handle)
268 {
269 	if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
270 		return 0;
271 	return 1;
272 }
273 
274 static inline void ext4_handle_sync(handle_t *handle)
275 {
276 	if (ext4_handle_valid(handle))
277 		handle->h_sync = 1;
278 }
279 
280 static inline int ext4_handle_is_aborted(handle_t *handle)
281 {
282 	if (ext4_handle_valid(handle))
283 		return is_handle_aborted(handle);
284 	return 0;
285 }
286 
287 static inline int ext4_free_metadata_revoke_credits(struct super_block *sb,
288 						    int blocks)
289 {
290 	/* Freeing each metadata block can result in freeing one cluster */
291 	return blocks * EXT4_SB(sb)->s_cluster_ratio;
292 }
293 
294 static inline int ext4_trans_default_revoke_credits(struct super_block *sb)
295 {
296 	return ext4_free_metadata_revoke_credits(sb, 8);
297 }
298 
299 #define ext4_journal_start_sb(sb, type, nblocks)			\
300 	__ext4_journal_start_sb((sb), __LINE__, (type), (nblocks), 0,	\
301 				ext4_trans_default_revoke_credits(sb))
302 
303 #define ext4_journal_start(inode, type, nblocks)			\
304 	__ext4_journal_start((inode), __LINE__, (type), (nblocks), 0,	\
305 			     ext4_trans_default_revoke_credits((inode)->i_sb))
306 
307 #define ext4_journal_start_with_reserve(inode, type, blocks, rsv_blocks)\
308 	__ext4_journal_start((inode), __LINE__, (type), (blocks), (rsv_blocks),\
309 			     ext4_trans_default_revoke_credits((inode)->i_sb))
310 
311 #define ext4_journal_start_with_revoke(inode, type, blocks, revoke_creds) \
312 	__ext4_journal_start((inode), __LINE__, (type), (blocks), 0,	\
313 			     (revoke_creds))
314 
315 static inline handle_t *__ext4_journal_start(struct inode *inode,
316 					     unsigned int line, int type,
317 					     int blocks, int rsv_blocks,
318 					     int revoke_creds)
319 {
320 	return __ext4_journal_start_sb(inode->i_sb, line, type, blocks,
321 				       rsv_blocks, revoke_creds);
322 }
323 
324 #define ext4_journal_stop(handle) \
325 	__ext4_journal_stop(__func__, __LINE__, (handle))
326 
327 #define ext4_journal_start_reserved(handle, type) \
328 	__ext4_journal_start_reserved((handle), __LINE__, (type))
329 
330 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
331 					int type);
332 
333 static inline handle_t *ext4_journal_current_handle(void)
334 {
335 	return journal_current_handle();
336 }
337 
338 static inline int ext4_journal_extend(handle_t *handle, int nblocks, int revoke)
339 {
340 	if (ext4_handle_valid(handle))
341 		return jbd2_journal_extend(handle, nblocks, revoke);
342 	return 0;
343 }
344 
345 static inline int ext4_journal_restart(handle_t *handle, int nblocks,
346 				       int revoke)
347 {
348 	if (ext4_handle_valid(handle))
349 		return jbd2__journal_restart(handle, nblocks, revoke, GFP_NOFS);
350 	return 0;
351 }
352 
353 int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
354 				  int extend_cred, int revoke_cred);
355 
356 
357 /*
358  * Ensure @handle has at least @check_creds credits available. If not,
359  * transaction will be extended or restarted to contain at least @extend_cred
360  * credits. Before restarting transaction @fn is executed to allow for cleanup
361  * before the transaction is restarted.
362  *
363  * The return value is < 0 in case of error, 0 in case the handle has enough
364  * credits or transaction extension succeeded, 1 in case transaction had to be
365  * restarted.
366  */
367 #define ext4_journal_ensure_credits_fn(handle, check_cred, extend_cred,	\
368 				       revoke_cred, fn) \
369 ({									\
370 	__label__ __ensure_end;						\
371 	int err = __ext4_journal_ensure_credits((handle), (check_cred),	\
372 					(extend_cred), (revoke_cred));	\
373 									\
374 	if (err <= 0)							\
375 		goto __ensure_end;					\
376 	err = (fn);							\
377 	if (err < 0)							\
378 		goto __ensure_end;					\
379 	err = ext4_journal_restart((handle), (extend_cred), (revoke_cred)); \
380 	if (err == 0)							\
381 		err = 1;						\
382 __ensure_end:								\
383 	err;								\
384 })
385 
386 /*
387  * Ensure given handle has at least requested amount of credits available,
388  * possibly restarting transaction if needed. We also make sure the transaction
389  * has space for at least ext4_trans_default_revoke_credits(sb) revoke records
390  * as freeing one or two blocks is very common pattern and requesting this is
391  * very cheap.
392  */
393 static inline int ext4_journal_ensure_credits(handle_t *handle, int credits,
394 					      int revoke_creds)
395 {
396 	return ext4_journal_ensure_credits_fn(handle, credits, credits,
397 				revoke_creds, 0);
398 }
399 
400 static inline int ext4_journal_blocks_per_page(struct inode *inode)
401 {
402 	if (EXT4_JOURNAL(inode) != NULL)
403 		return jbd2_journal_blocks_per_page(inode);
404 	return 0;
405 }
406 
407 static inline int ext4_journal_force_commit(journal_t *journal)
408 {
409 	if (journal)
410 		return jbd2_journal_force_commit(journal);
411 	return 0;
412 }
413 
414 static inline int ext4_jbd2_inode_add_write(handle_t *handle,
415 		struct inode *inode, loff_t start_byte, loff_t length)
416 {
417 	if (ext4_handle_valid(handle))
418 		return jbd2_journal_inode_ranged_write(handle,
419 				EXT4_I(inode)->jinode, start_byte, length);
420 	return 0;
421 }
422 
423 static inline int ext4_jbd2_inode_add_wait(handle_t *handle,
424 		struct inode *inode, loff_t start_byte, loff_t length)
425 {
426 	if (ext4_handle_valid(handle))
427 		return jbd2_journal_inode_ranged_wait(handle,
428 				EXT4_I(inode)->jinode, start_byte, length);
429 	return 0;
430 }
431 
432 static inline void ext4_update_inode_fsync_trans(handle_t *handle,
433 						 struct inode *inode,
434 						 int datasync)
435 {
436 	struct ext4_inode_info *ei = EXT4_I(inode);
437 
438 	if (ext4_handle_valid(handle) && !is_handle_aborted(handle)) {
439 		ei->i_sync_tid = handle->h_transaction->t_tid;
440 		if (datasync)
441 			ei->i_datasync_tid = handle->h_transaction->t_tid;
442 	}
443 }
444 
445 /* super.c */
446 int ext4_force_commit(struct super_block *sb);
447 
448 /*
449  * Ext4 inode journal modes
450  */
451 #define EXT4_INODE_JOURNAL_DATA_MODE	0x01 /* journal data mode */
452 #define EXT4_INODE_ORDERED_DATA_MODE	0x02 /* ordered data mode */
453 #define EXT4_INODE_WRITEBACK_DATA_MODE	0x04 /* writeback data mode */
454 
455 int ext4_inode_journal_mode(struct inode *inode);
456 
457 static inline int ext4_should_journal_data(struct inode *inode)
458 {
459 	return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE;
460 }
461 
462 static inline int ext4_should_order_data(struct inode *inode)
463 {
464 	return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
465 }
466 
467 static inline int ext4_should_writeback_data(struct inode *inode)
468 {
469 	return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE;
470 }
471 
472 static inline int ext4_free_data_revoke_credits(struct inode *inode, int blocks)
473 {
474 	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
475 		return 0;
476 	if (!ext4_should_journal_data(inode))
477 		return 0;
478 	/*
479 	 * Data blocks in one extent are contiguous, just account for partial
480 	 * clusters at extent boundaries
481 	 */
482 	return blocks + 2*(EXT4_SB(inode->i_sb)->s_cluster_ratio - 1);
483 }
484 
485 /*
486  * This function controls whether or not we should try to go down the
487  * dioread_nolock code paths, which makes it safe to avoid taking
488  * i_mutex for direct I/O reads.  This only works for extent-based
489  * files, and it doesn't work if data journaling is enabled, since the
490  * dioread_nolock code uses b_private to pass information back to the
491  * I/O completion handler, and this conflicts with the jbd's use of
492  * b_private.
493  */
494 static inline int ext4_should_dioread_nolock(struct inode *inode)
495 {
496 	if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
497 		return 0;
498 	if (!S_ISREG(inode->i_mode))
499 		return 0;
500 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
501 		return 0;
502 	if (ext4_should_journal_data(inode))
503 		return 0;
504 	/* temporary fix to prevent generic/422 test failures */
505 	if (!test_opt(inode->i_sb, DELALLOC))
506 		return 0;
507 	return 1;
508 }
509 
510 #endif	/* _EXT4_JBD2_H */
511