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 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
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 int __ext4_handle_dirty_super(const char *where, unsigned int line,
248 			      handle_t *handle, struct super_block *sb);
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 #define ext4_handle_dirty_super(handle, sb) \
261 	__ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb))
262 
263 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
264 				  int type, int blocks, int rsv_blocks);
265 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
266 
267 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
268 
269 /* Note:  Do not use this for NULL handles.  This is only to determine if
270  * a properly allocated handle is using a journal or not. */
ext4_handle_valid(handle_t * handle)271 static inline int ext4_handle_valid(handle_t *handle)
272 {
273 	if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
274 		return 0;
275 	return 1;
276 }
277 
ext4_handle_sync(handle_t * handle)278 static inline void ext4_handle_sync(handle_t *handle)
279 {
280 	if (ext4_handle_valid(handle))
281 		handle->h_sync = 1;
282 }
283 
ext4_handle_is_aborted(handle_t * handle)284 static inline int ext4_handle_is_aborted(handle_t *handle)
285 {
286 	if (ext4_handle_valid(handle))
287 		return is_handle_aborted(handle);
288 	return 0;
289 }
290 
ext4_handle_has_enough_credits(handle_t * handle,int needed)291 static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
292 {
293 	if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
294 		return 0;
295 	return 1;
296 }
297 
298 #define ext4_journal_start_sb(sb, type, nblocks)			\
299 	__ext4_journal_start_sb((sb), __LINE__, (type), (nblocks), 0)
300 
301 #define ext4_journal_start(inode, type, nblocks)			\
302 	__ext4_journal_start((inode), __LINE__, (type), (nblocks), 0)
303 
304 #define ext4_journal_start_with_reserve(inode, type, blocks, rsv_blocks) \
305 	__ext4_journal_start((inode), __LINE__, (type), (blocks), (rsv_blocks))
306 
__ext4_journal_start(struct inode * inode,unsigned int line,int type,int blocks,int rsv_blocks)307 static inline handle_t *__ext4_journal_start(struct inode *inode,
308 					     unsigned int line, int type,
309 					     int blocks, int rsv_blocks)
310 {
311 	return __ext4_journal_start_sb(inode->i_sb, line, type, blocks,
312 				       rsv_blocks);
313 }
314 
315 #define ext4_journal_stop(handle) \
316 	__ext4_journal_stop(__func__, __LINE__, (handle))
317 
318 #define ext4_journal_start_reserved(handle, type) \
319 	__ext4_journal_start_reserved((handle), __LINE__, (type))
320 
321 handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
322 					int type);
323 
ext4_journal_free_reserved(handle_t * handle)324 static inline void ext4_journal_free_reserved(handle_t *handle)
325 {
326 	if (ext4_handle_valid(handle))
327 		jbd2_journal_free_reserved(handle);
328 }
329 
ext4_journal_current_handle(void)330 static inline handle_t *ext4_journal_current_handle(void)
331 {
332 	return journal_current_handle();
333 }
334 
ext4_journal_extend(handle_t * handle,int nblocks)335 static inline int ext4_journal_extend(handle_t *handle, int nblocks)
336 {
337 	if (ext4_handle_valid(handle))
338 		return jbd2_journal_extend(handle, nblocks);
339 	return 0;
340 }
341 
ext4_journal_restart(handle_t * handle,int nblocks)342 static inline int ext4_journal_restart(handle_t *handle, int nblocks)
343 {
344 	if (ext4_handle_valid(handle))
345 		return jbd2_journal_restart(handle, nblocks);
346 	return 0;
347 }
348 
ext4_journal_blocks_per_page(struct inode * inode)349 static inline int ext4_journal_blocks_per_page(struct inode *inode)
350 {
351 	if (EXT4_JOURNAL(inode) != NULL)
352 		return jbd2_journal_blocks_per_page(inode);
353 	return 0;
354 }
355 
ext4_journal_force_commit(journal_t * journal)356 static inline int ext4_journal_force_commit(journal_t *journal)
357 {
358 	if (journal)
359 		return jbd2_journal_force_commit(journal);
360 	return 0;
361 }
362 
ext4_jbd2_inode_add_write(handle_t * handle,struct inode * inode,loff_t start_byte,loff_t length)363 static inline int ext4_jbd2_inode_add_write(handle_t *handle,
364 		struct inode *inode, loff_t start_byte, loff_t length)
365 {
366 	if (ext4_handle_valid(handle))
367 		return jbd2_journal_inode_ranged_write(handle,
368 				EXT4_I(inode)->jinode, start_byte, length);
369 	return 0;
370 }
371 
ext4_jbd2_inode_add_wait(handle_t * handle,struct inode * inode,loff_t start_byte,loff_t length)372 static inline int ext4_jbd2_inode_add_wait(handle_t *handle,
373 		struct inode *inode, loff_t start_byte, loff_t length)
374 {
375 	if (ext4_handle_valid(handle))
376 		return jbd2_journal_inode_ranged_wait(handle,
377 				EXT4_I(inode)->jinode, start_byte, length);
378 	return 0;
379 }
380 
ext4_update_inode_fsync_trans(handle_t * handle,struct inode * inode,int datasync)381 static inline void ext4_update_inode_fsync_trans(handle_t *handle,
382 						 struct inode *inode,
383 						 int datasync)
384 {
385 	struct ext4_inode_info *ei = EXT4_I(inode);
386 
387 	if (ext4_handle_valid(handle) && !is_handle_aborted(handle)) {
388 		ei->i_sync_tid = handle->h_transaction->t_tid;
389 		if (datasync)
390 			ei->i_datasync_tid = handle->h_transaction->t_tid;
391 	}
392 }
393 
394 /* super.c */
395 int ext4_force_commit(struct super_block *sb);
396 
397 /*
398  * Ext4 inode journal modes
399  */
400 #define EXT4_INODE_JOURNAL_DATA_MODE	0x01 /* journal data mode */
401 #define EXT4_INODE_ORDERED_DATA_MODE	0x02 /* ordered data mode */
402 #define EXT4_INODE_WRITEBACK_DATA_MODE	0x04 /* writeback data mode */
403 
ext4_inode_journal_mode(struct inode * inode)404 static inline int ext4_inode_journal_mode(struct inode *inode)
405 {
406 	if (EXT4_JOURNAL(inode) == NULL)
407 		return EXT4_INODE_WRITEBACK_DATA_MODE;	/* writeback */
408 	/* We do not support data journalling with delayed allocation */
409 	if (!S_ISREG(inode->i_mode) ||
410 	    test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
411 	    (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
412 	    !test_opt(inode->i_sb, DELALLOC))) {
413 		/* We do not support data journalling for encrypted data */
414 		if (S_ISREG(inode->i_mode) && ext4_encrypted_inode(inode))
415 			return EXT4_INODE_ORDERED_DATA_MODE;  /* ordered */
416 		return EXT4_INODE_JOURNAL_DATA_MODE;	/* journal data */
417 	}
418 	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
419 		return EXT4_INODE_ORDERED_DATA_MODE;	/* ordered */
420 	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
421 		return EXT4_INODE_WRITEBACK_DATA_MODE;	/* writeback */
422 	BUG();
423 }
424 
ext4_should_journal_data(struct inode * inode)425 static inline int ext4_should_journal_data(struct inode *inode)
426 {
427 	return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE;
428 }
429 
ext4_should_order_data(struct inode * inode)430 static inline int ext4_should_order_data(struct inode *inode)
431 {
432 	return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
433 }
434 
ext4_should_writeback_data(struct inode * inode)435 static inline int ext4_should_writeback_data(struct inode *inode)
436 {
437 	return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE;
438 }
439 
440 /*
441  * This function controls whether or not we should try to go down the
442  * dioread_nolock code paths, which makes it safe to avoid taking
443  * i_mutex for direct I/O reads.  This only works for extent-based
444  * files, and it doesn't work if data journaling is enabled, since the
445  * dioread_nolock code uses b_private to pass information back to the
446  * I/O completion handler, and this conflicts with the jbd's use of
447  * b_private.
448  */
ext4_should_dioread_nolock(struct inode * inode)449 static inline int ext4_should_dioread_nolock(struct inode *inode)
450 {
451 	if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
452 		return 0;
453 	if (!S_ISREG(inode->i_mode))
454 		return 0;
455 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
456 		return 0;
457 	if (ext4_should_journal_data(inode))
458 		return 0;
459 	return 1;
460 }
461 
462 #endif	/* _EXT4_JBD2_H */
463