• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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) ((test_opt(sb, QUOTA) ||\
90 		ext4_has_feature_quota(sb)) ? 1 : 0)
91 /* Amount of blocks needed for quota insert/delete - we do some block writes
92  * but inode, sb and group updates are done only once */
93 #define EXT4_QUOTA_INIT_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
94 		ext4_has_feature_quota(sb)) ?\
95 		(DQUOT_INIT_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
96 		 +3+DQUOT_INIT_REWRITE) : 0)
97 
98 #define EXT4_QUOTA_DEL_BLOCKS(sb) ((test_opt(sb, QUOTA) ||\
99 		ext4_has_feature_quota(sb)) ?\
100 		(DQUOT_DEL_ALLOC*(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)\
101 		 +3+DQUOT_DEL_REWRITE) : 0)
102 #else
103 #define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
104 #define EXT4_QUOTA_INIT_BLOCKS(sb) 0
105 #define EXT4_QUOTA_DEL_BLOCKS(sb) 0
106 #endif
107 #define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb))
108 #define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
109 #define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (EXT4_MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
110 
111 /*
112  * Ext4 handle operation types -- for logging purposes
113  */
114 #define EXT4_HT_MISC             0
115 #define EXT4_HT_INODE            1
116 #define EXT4_HT_WRITE_PAGE       2
117 #define EXT4_HT_MAP_BLOCKS       3
118 #define EXT4_HT_DIR              4
119 #define EXT4_HT_TRUNCATE         5
120 #define EXT4_HT_QUOTA            6
121 #define EXT4_HT_RESIZE           7
122 #define EXT4_HT_MIGRATE          8
123 #define EXT4_HT_MOVE_EXTENTS     9
124 #define EXT4_HT_XATTR           10
125 #define EXT4_HT_EXT_CONVERT     11
126 #define EXT4_HT_MAX             12
127 
128 /**
129  *   struct ext4_journal_cb_entry - Base structure for callback information.
130  *
131  *   This struct is a 'seed' structure for a using with your own callback
132  *   structs. If you are using callbacks you must allocate one of these
133  *   or another struct of your own definition which has this struct
134  *   as it's first element and pass it to ext4_journal_callback_add().
135  */
136 struct ext4_journal_cb_entry {
137 	/* list information for other callbacks attached to the same handle */
138 	struct list_head jce_list;
139 
140 	/*  Function to call with this callback structure */
141 	void (*jce_func)(struct super_block *sb,
142 			 struct ext4_journal_cb_entry *jce, int error);
143 
144 	/* user data goes here */
145 };
146 
147 /**
148  * ext4_journal_callback_add: add a function to call after transaction commit
149  * @handle: active journal transaction handle to register callback on
150  * @func: callback function to call after the transaction has committed:
151  *        @sb: superblock of current filesystem for transaction
152  *        @jce: returned journal callback data
153  *        @rc: journal state at commit (0 = transaction committed properly)
154  * @jce: journal callback data (internal and function private data struct)
155  *
156  * The registered function will be called in the context of the journal thread
157  * after the transaction for which the handle was created has completed.
158  *
159  * No locks are held when the callback function is called, so it is safe to
160  * call blocking functions from within the callback, but the callback should
161  * not block or run for too long, or the filesystem will be blocked waiting for
162  * the next transaction to commit. No journaling functions can be used, or
163  * there is a risk of deadlock.
164  *
165  * There is no guaranteed calling order of multiple registered callbacks on
166  * the same transaction.
167  */
_ext4_journal_callback_add(handle_t * handle,struct ext4_journal_cb_entry * jce)168 static inline void _ext4_journal_callback_add(handle_t *handle,
169 			struct ext4_journal_cb_entry *jce)
170 {
171 	/* Add the jce to transaction's private list */
172 	list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list);
173 }
174 
ext4_journal_callback_add(handle_t * handle,void (* func)(struct super_block * sb,struct ext4_journal_cb_entry * jce,int rc),struct ext4_journal_cb_entry * jce)175 static inline void ext4_journal_callback_add(handle_t *handle,
176 			void (*func)(struct super_block *sb,
177 				     struct ext4_journal_cb_entry *jce,
178 				     int rc),
179 			struct ext4_journal_cb_entry *jce)
180 {
181 	struct ext4_sb_info *sbi =
182 			EXT4_SB(handle->h_transaction->t_journal->j_private);
183 
184 	/* Add the jce to transaction's private list */
185 	jce->jce_func = func;
186 	spin_lock(&sbi->s_md_lock);
187 	_ext4_journal_callback_add(handle, jce);
188 	spin_unlock(&sbi->s_md_lock);
189 }
190 
191 
192 /**
193  * ext4_journal_callback_del: delete a registered callback
194  * @handle: active journal transaction handle on which callback was registered
195  * @jce: registered journal callback entry to unregister
196  * Return true if object was successfully removed
197  */
ext4_journal_callback_try_del(handle_t * handle,struct ext4_journal_cb_entry * jce)198 static inline bool ext4_journal_callback_try_del(handle_t *handle,
199 					     struct ext4_journal_cb_entry *jce)
200 {
201 	bool deleted;
202 	struct ext4_sb_info *sbi =
203 			EXT4_SB(handle->h_transaction->t_journal->j_private);
204 
205 	spin_lock(&sbi->s_md_lock);
206 	deleted = !list_empty(&jce->jce_list);
207 	list_del_init(&jce->jce_list);
208 	spin_unlock(&sbi->s_md_lock);
209 	return deleted;
210 }
211 
212 int
213 ext4_mark_iloc_dirty(handle_t *handle,
214 		     struct inode *inode,
215 		     struct ext4_iloc *iloc);
216 
217 /*
218  * On success, We end up with an outstanding reference count against
219  * iloc->bh.  This _must_ be cleaned up later.
220  */
221 
222 int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
223 			struct ext4_iloc *iloc);
224 
225 #define ext4_mark_inode_dirty(__h, __i)					\
226 		__ext4_mark_inode_dirty((__h), (__i), __func__, __LINE__)
227 int __ext4_mark_inode_dirty(handle_t *handle, struct inode *inode,
228 				const char *func, unsigned int line);
229 
230 int ext4_expand_extra_isize(struct inode *inode,
231 			    unsigned int new_extra_isize,
232 			    struct ext4_iloc *iloc);
233 /*
234  * Wrapper functions with which ext4 calls into JBD.
235  */
236 int __ext4_journal_get_write_access(const char *where, unsigned int line,
237 				    handle_t *handle, struct buffer_head *bh);
238 
239 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
240 		  int is_metadata, struct inode *inode,
241 		  struct buffer_head *bh, ext4_fsblk_t blocknr);
242 
243 int __ext4_journal_get_create_access(const char *where, unsigned int line,
244 				handle_t *handle, struct buffer_head *bh);
245 
246 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
247 				 handle_t *handle, struct inode *inode,
248 				 struct buffer_head *bh);
249 
250 #define ext4_journal_get_write_access(handle, bh) \
251 	__ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
252 #define ext4_forget(handle, is_metadata, inode, bh, block_nr) \
253 	__ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \
254 		      (bh), (block_nr))
255 #define ext4_journal_get_create_access(handle, bh) \
256 	__ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh))
257 #define ext4_handle_dirty_metadata(handle, inode, bh) \
258 	__ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
259 				     (bh))
260 
261 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
262 				  int type, int blocks, int rsv_blocks,
263 				  int revoke_creds);
264 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
265 
266 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
267 
268 /* Note:  Do not use this for NULL handles.  This is only to determine if
269  * a properly allocated handle is using a journal or not. */
ext4_handle_valid(handle_t * handle)270 static inline int ext4_handle_valid(handle_t *handle)
271 {
272 	if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
273 		return 0;
274 	return 1;
275 }
276 
ext4_handle_sync(handle_t * handle)277 static inline void ext4_handle_sync(handle_t *handle)
278 {
279 	if (ext4_handle_valid(handle))
280 		handle->h_sync = 1;
281 }
282 
ext4_handle_is_aborted(handle_t * handle)283 static inline int ext4_handle_is_aborted(handle_t *handle)
284 {
285 	if (ext4_handle_valid(handle))
286 		return is_handle_aborted(handle);
287 	return 0;
288 }
289 
ext4_free_metadata_revoke_credits(struct super_block * sb,int blocks)290 static inline int ext4_free_metadata_revoke_credits(struct super_block *sb,
291 						    int blocks)
292 {
293 	/* Freeing each metadata block can result in freeing one cluster */
294 	return blocks * EXT4_SB(sb)->s_cluster_ratio;
295 }
296 
ext4_trans_default_revoke_credits(struct super_block * sb)297 static inline int ext4_trans_default_revoke_credits(struct super_block *sb)
298 {
299 	return ext4_free_metadata_revoke_credits(sb, 8);
300 }
301 
302 #define ext4_journal_start_sb(sb, type, nblocks)			\
303 	__ext4_journal_start_sb((sb), __LINE__, (type), (nblocks), 0,	\
304 				ext4_trans_default_revoke_credits(sb))
305 
306 #define ext4_journal_start(inode, type, nblocks)			\
307 	__ext4_journal_start((inode), __LINE__, (type), (nblocks), 0,	\
308 			     ext4_trans_default_revoke_credits((inode)->i_sb))
309 
310 #define ext4_journal_start_with_reserve(inode, type, blocks, rsv_blocks)\
311 	__ext4_journal_start((inode), __LINE__, (type), (blocks), (rsv_blocks),\
312 			     ext4_trans_default_revoke_credits((inode)->i_sb))
313 
314 #define ext4_journal_start_with_revoke(inode, type, blocks, revoke_creds) \
315 	__ext4_journal_start((inode), __LINE__, (type), (blocks), 0,	\
316 			     (revoke_creds))
317 
__ext4_journal_start(struct inode * inode,unsigned int line,int type,int blocks,int rsv_blocks,int revoke_creds)318 static inline handle_t *__ext4_journal_start(struct inode *inode,
319 					     unsigned int line, int type,
320 					     int blocks, int rsv_blocks,
321 					     int revoke_creds)
322 {
323 	return __ext4_journal_start_sb(inode->i_sb, line, type, blocks,
324 				       rsv_blocks, revoke_creds);
325 }
326 
327 #define ext4_journal_stop(handle) \
328 	__ext4_journal_stop(__func__, __LINE__, (handle))
329 
330 #define ext4_journal_start_reserved(handle, type) \
331 	__ext4_journal_start_reserved((handle), __LINE__, (type))
332 
333 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
334 					int type);
335 
ext4_journal_current_handle(void)336 static inline handle_t *ext4_journal_current_handle(void)
337 {
338 	return journal_current_handle();
339 }
340 
ext4_journal_extend(handle_t * handle,int nblocks,int revoke)341 static inline int ext4_journal_extend(handle_t *handle, int nblocks, int revoke)
342 {
343 	if (ext4_handle_valid(handle))
344 		return jbd2_journal_extend(handle, nblocks, revoke);
345 	return 0;
346 }
347 
ext4_journal_restart(handle_t * handle,int nblocks,int revoke)348 static inline int ext4_journal_restart(handle_t *handle, int nblocks,
349 				       int revoke)
350 {
351 	if (ext4_handle_valid(handle))
352 		return jbd2__journal_restart(handle, nblocks, revoke, GFP_NOFS);
353 	return 0;
354 }
355 
356 int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
357 				  int extend_cred, int revoke_cred);
358 
359 
360 /*
361  * Ensure @handle has at least @check_creds credits available. If not,
362  * transaction will be extended or restarted to contain at least @extend_cred
363  * credits. Before restarting transaction @fn is executed to allow for cleanup
364  * before the transaction is restarted.
365  *
366  * The return value is < 0 in case of error, 0 in case the handle has enough
367  * credits or transaction extension succeeded, 1 in case transaction had to be
368  * restarted.
369  */
370 #define ext4_journal_ensure_credits_fn(handle, check_cred, extend_cred,	\
371 				       revoke_cred, fn) \
372 ({									\
373 	__label__ __ensure_end;						\
374 	int err = __ext4_journal_ensure_credits((handle), (check_cred),	\
375 					(extend_cred), (revoke_cred));	\
376 									\
377 	if (err <= 0)							\
378 		goto __ensure_end;					\
379 	err = (fn);							\
380 	if (err < 0)							\
381 		goto __ensure_end;					\
382 	err = ext4_journal_restart((handle), (extend_cred), (revoke_cred)); \
383 	if (err == 0)							\
384 		err = 1;						\
385 __ensure_end:								\
386 	err;								\
387 })
388 
389 /*
390  * Ensure given handle has at least requested amount of credits available,
391  * possibly restarting transaction if needed. We also make sure the transaction
392  * has space for at least ext4_trans_default_revoke_credits(sb) revoke records
393  * as freeing one or two blocks is very common pattern and requesting this is
394  * very cheap.
395  */
ext4_journal_ensure_credits(handle_t * handle,int credits,int revoke_creds)396 static inline int ext4_journal_ensure_credits(handle_t *handle, int credits,
397 					      int revoke_creds)
398 {
399 	return ext4_journal_ensure_credits_fn(handle, credits, credits,
400 				revoke_creds, 0);
401 }
402 
ext4_journal_blocks_per_page(struct inode * inode)403 static inline int ext4_journal_blocks_per_page(struct inode *inode)
404 {
405 	if (EXT4_JOURNAL(inode) != NULL)
406 		return jbd2_journal_blocks_per_page(inode);
407 	return 0;
408 }
409 
ext4_journal_force_commit(journal_t * journal)410 static inline int ext4_journal_force_commit(journal_t *journal)
411 {
412 	if (journal)
413 		return jbd2_journal_force_commit(journal);
414 	return 0;
415 }
416 
ext4_jbd2_inode_add_write(handle_t * handle,struct inode * inode,loff_t start_byte,loff_t length)417 static inline int ext4_jbd2_inode_add_write(handle_t *handle,
418 		struct inode *inode, loff_t start_byte, loff_t length)
419 {
420 	if (ext4_handle_valid(handle))
421 		return jbd2_journal_inode_ranged_write(handle,
422 				EXT4_I(inode)->jinode, start_byte, length);
423 	return 0;
424 }
425 
ext4_jbd2_inode_add_wait(handle_t * handle,struct inode * inode,loff_t start_byte,loff_t length)426 static inline int ext4_jbd2_inode_add_wait(handle_t *handle,
427 		struct inode *inode, loff_t start_byte, loff_t length)
428 {
429 	if (ext4_handle_valid(handle))
430 		return jbd2_journal_inode_ranged_wait(handle,
431 				EXT4_I(inode)->jinode, start_byte, length);
432 	return 0;
433 }
434 
ext4_update_inode_fsync_trans(handle_t * handle,struct inode * inode,int datasync)435 static inline void ext4_update_inode_fsync_trans(handle_t *handle,
436 						 struct inode *inode,
437 						 int datasync)
438 {
439 	struct ext4_inode_info *ei = EXT4_I(inode);
440 
441 	if (ext4_handle_valid(handle) && !is_handle_aborted(handle)) {
442 		ei->i_sync_tid = handle->h_transaction->t_tid;
443 		if (datasync)
444 			ei->i_datasync_tid = handle->h_transaction->t_tid;
445 	}
446 }
447 
448 /* super.c */
449 int ext4_force_commit(struct super_block *sb);
450 
451 /*
452  * Ext4 inode journal modes
453  */
454 #define EXT4_INODE_JOURNAL_DATA_MODE	0x01 /* journal data mode */
455 #define EXT4_INODE_ORDERED_DATA_MODE	0x02 /* ordered data mode */
456 #define EXT4_INODE_WRITEBACK_DATA_MODE	0x04 /* writeback data mode */
457 
458 int ext4_inode_journal_mode(struct inode *inode);
459 
ext4_should_journal_data(struct inode * inode)460 static inline int ext4_should_journal_data(struct inode *inode)
461 {
462 	return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE;
463 }
464 
ext4_should_order_data(struct inode * inode)465 static inline int ext4_should_order_data(struct inode *inode)
466 {
467 	return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
468 }
469 
ext4_should_writeback_data(struct inode * inode)470 static inline int ext4_should_writeback_data(struct inode *inode)
471 {
472 	return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE;
473 }
474 
ext4_free_data_revoke_credits(struct inode * inode,int blocks)475 static inline int ext4_free_data_revoke_credits(struct inode *inode, int blocks)
476 {
477 	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
478 		return 0;
479 	if (!ext4_should_journal_data(inode))
480 		return 0;
481 	/*
482 	 * Data blocks in one extent are contiguous, just account for partial
483 	 * clusters at extent boundaries
484 	 */
485 	return blocks + 2*(EXT4_SB(inode->i_sb)->s_cluster_ratio - 1);
486 }
487 
488 /*
489  * This function controls whether or not we should try to go down the
490  * dioread_nolock code paths, which makes it safe to avoid taking
491  * i_mutex for direct I/O reads.  This only works for extent-based
492  * files, and it doesn't work if data journaling is enabled, since the
493  * dioread_nolock code uses b_private to pass information back to the
494  * I/O completion handler, and this conflicts with the jbd's use of
495  * b_private.
496  */
ext4_should_dioread_nolock(struct inode * inode)497 static inline int ext4_should_dioread_nolock(struct inode *inode)
498 {
499 	if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
500 		return 0;
501 	if (!S_ISREG(inode->i_mode))
502 		return 0;
503 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
504 		return 0;
505 	if (ext4_should_journal_data(inode))
506 		return 0;
507 	/* temporary fix to prevent generic/422 test failures */
508 	if (!test_opt(inode->i_sb, DELALLOC))
509 		return 0;
510 	return 1;
511 }
512 
513 #endif	/* _EXT4_JBD2_H */
514