1 /*
2  * ext4_jbd2.h
3  *
4  * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
5  *
6  * Copyright 1998--1999 Red Hat corp --- All Rights Reserved
7  *
8  * This file is part of the Linux kernel and is made available under
9  * the terms of the GNU General Public License, version 2, or at your
10  * option, any later version, incorporated herein by reference.
11  *
12  * Ext4-specific journaling extensions.
13  */
14 
15 #ifndef _EXT4_JBD2_H
16 #define _EXT4_JBD2_H
17 
18 #include <linux/fs.h>
19 #include <linux/jbd2.h>
20 #include "ext4.h"
21 
22 #define EXT4_JOURNAL(inode)	(EXT4_SB((inode)->i_sb)->s_journal)
23 
24 /* Define the number of blocks we need to account to a transaction to
25  * modify one block of data.
26  *
27  * We may have to touch one inode, one bitmap buffer, up to three
28  * indirection blocks, the group and superblock summaries, and the data
29  * block to complete the transaction.
30  *
31  * For extents-enabled fs we may have to allocate and modify up to
32  * 5 levels of tree + root which are stored in the inode. */
33 
34 #define EXT4_SINGLEDATA_TRANS_BLOCKS(sb)				\
35 	(EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)   \
36 	 ? 27U : 8U)
37 
38 /* Extended attribute operations touch at most two data buffers,
39  * two bitmap buffers, and two group summaries, in addition to the inode
40  * and the superblock, which are already accounted for. */
41 
42 #define EXT4_XATTR_TRANS_BLOCKS		6U
43 
44 /* Define the minimum size for a transaction which modifies data.  This
45  * needs to take into account the fact that we may end up modifying two
46  * quota files too (one for the group, one for the user quota).  The
47  * superblock only gets updated once, of course, so don't bother
48  * counting that again for the quota updates. */
49 
50 #define EXT4_DATA_TRANS_BLOCKS(sb)	(EXT4_SINGLEDATA_TRANS_BLOCKS(sb) + \
51 					 EXT4_XATTR_TRANS_BLOCKS - 2 + \
52 					 EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
53 
54 /*
55  * Define the number of metadata blocks we need to account to modify data.
56  *
57  * This include super block, inode block, quota blocks and xattr blocks
58  */
59 #define EXT4_META_TRANS_BLOCKS(sb)	(EXT4_XATTR_TRANS_BLOCKS + \
60 					EXT4_MAXQUOTAS_TRANS_BLOCKS(sb))
61 
62 /* Delete operations potentially hit one directory's namespace plus an
63  * entire inode, plus arbitrary amounts of bitmap/indirection data.  Be
64  * generous.  We can grow the delete transaction later if necessary. */
65 
66 #define EXT4_DELETE_TRANS_BLOCKS(sb)	(2 * EXT4_DATA_TRANS_BLOCKS(sb) + 64)
67 
68 /* Define an arbitrary limit for the amount of data we will anticipate
69  * writing to any given transaction.  For unbounded transactions such as
70  * write(2) and truncate(2) we can write more than this, but we always
71  * start off at the maximum transaction size and grow the transaction
72  * optimistically as we go. */
73 
74 #define EXT4_MAX_TRANS_DATA		64U
75 
76 /* We break up a large truncate or write transaction once the handle's
77  * buffer credits gets this low, we need either to extend the
78  * transaction or to start a new one.  Reserve enough space here for
79  * inode, bitmap, superblock, group and indirection updates for at least
80  * one block, plus two quota updates.  Quota allocations are not
81  * needed. */
82 
83 #define EXT4_RESERVE_TRANS_BLOCKS	12U
84 
85 #define EXT4_INDEX_EXTRA_TRANS_BLOCKS	8
86 
87 #ifdef CONFIG_QUOTA
88 /* Amount of blocks needed for quota update - we know that the structure was
89  * allocated so we need to update only data block */
90 #define EXT4_QUOTA_TRANS_BLOCKS(sb) (test_opt(sb, QUOTA) ? 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) ? (DQUOT_INIT_ALLOC*\
94 		(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_INIT_REWRITE) : 0)
95 
96 #define EXT4_QUOTA_DEL_BLOCKS(sb) (test_opt(sb, QUOTA) ? (DQUOT_DEL_ALLOC*\
97 		(EXT4_SINGLEDATA_TRANS_BLOCKS(sb)-3)+3+DQUOT_DEL_REWRITE) : 0)
98 #else
99 #define EXT4_QUOTA_TRANS_BLOCKS(sb) 0
100 #define EXT4_QUOTA_INIT_BLOCKS(sb) 0
101 #define EXT4_QUOTA_DEL_BLOCKS(sb) 0
102 #endif
103 #define EXT4_MAXQUOTAS_TRANS_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_TRANS_BLOCKS(sb))
104 #define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
105 #define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
106 
107 /**
108  *   struct ext4_journal_cb_entry - Base structure for callback information.
109  *
110  *   This struct is a 'seed' structure for a using with your own callback
111  *   structs. If you are using callbacks you must allocate one of these
112  *   or another struct of your own definition which has this struct
113  *   as it's first element and pass it to ext4_journal_callback_add().
114  */
115 struct ext4_journal_cb_entry {
116 	/* list information for other callbacks attached to the same handle */
117 	struct list_head jce_list;
118 
119 	/*  Function to call with this callback structure */
120 	void (*jce_func)(struct super_block *sb,
121 			 struct ext4_journal_cb_entry *jce, int error);
122 
123 	/* user data goes here */
124 };
125 
126 /**
127  * ext4_journal_callback_add: add a function to call after transaction commit
128  * @handle: active journal transaction handle to register callback on
129  * @func: callback function to call after the transaction has committed:
130  *        @sb: superblock of current filesystem for transaction
131  *        @jce: returned journal callback data
132  *        @rc: journal state at commit (0 = transaction committed properly)
133  * @jce: journal callback data (internal and function private data struct)
134  *
135  * The registered function will be called in the context of the journal thread
136  * after the transaction for which the handle was created has completed.
137  *
138  * No locks are held when the callback function is called, so it is safe to
139  * call blocking functions from within the callback, but the callback should
140  * not block or run for too long, or the filesystem will be blocked waiting for
141  * the next transaction to commit. No journaling functions can be used, or
142  * there is a risk of deadlock.
143  *
144  * There is no guaranteed calling order of multiple registered callbacks on
145  * the same transaction.
146  */
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)147 static inline void ext4_journal_callback_add(handle_t *handle,
148 			void (*func)(struct super_block *sb,
149 				     struct ext4_journal_cb_entry *jce,
150 				     int rc),
151 			struct ext4_journal_cb_entry *jce)
152 {
153 	struct ext4_sb_info *sbi =
154 			EXT4_SB(handle->h_transaction->t_journal->j_private);
155 
156 	/* Add the jce to transaction's private list */
157 	jce->jce_func = func;
158 	spin_lock(&sbi->s_md_lock);
159 	list_add_tail(&jce->jce_list, &handle->h_transaction->t_private_list);
160 	spin_unlock(&sbi->s_md_lock);
161 }
162 
163 /**
164  * ext4_journal_callback_del: delete a registered callback
165  * @handle: active journal transaction handle on which callback was registered
166  * @jce: registered journal callback entry to unregister
167  * Return true if object was sucessfully removed
168  */
ext4_journal_callback_try_del(handle_t * handle,struct ext4_journal_cb_entry * jce)169 static inline bool ext4_journal_callback_try_del(handle_t *handle,
170 					     struct ext4_journal_cb_entry *jce)
171 {
172 	bool deleted;
173 	struct ext4_sb_info *sbi =
174 			EXT4_SB(handle->h_transaction->t_journal->j_private);
175 
176 	spin_lock(&sbi->s_md_lock);
177 	deleted = !list_empty(&jce->jce_list);
178 	list_del_init(&jce->jce_list);
179 	spin_unlock(&sbi->s_md_lock);
180 	return deleted;
181 }
182 
183 int
184 ext4_mark_iloc_dirty(handle_t *handle,
185 		     struct inode *inode,
186 		     struct ext4_iloc *iloc);
187 
188 /*
189  * On success, We end up with an outstanding reference count against
190  * iloc->bh.  This _must_ be cleaned up later.
191  */
192 
193 int ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
194 			struct ext4_iloc *iloc);
195 
196 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
197 
198 /*
199  * Wrapper functions with which ext4 calls into JBD.
200  */
201 void ext4_journal_abort_handle(const char *caller, unsigned int line,
202 			       const char *err_fn,
203 		struct buffer_head *bh, handle_t *handle, int err);
204 
205 int __ext4_journal_get_write_access(const char *where, unsigned int line,
206 				    handle_t *handle, struct buffer_head *bh);
207 
208 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
209 		  int is_metadata, struct inode *inode,
210 		  struct buffer_head *bh, ext4_fsblk_t blocknr);
211 
212 int __ext4_journal_get_create_access(const char *where, unsigned int line,
213 				handle_t *handle, struct buffer_head *bh);
214 
215 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
216 				 handle_t *handle, struct inode *inode,
217 				 struct buffer_head *bh);
218 
219 int __ext4_handle_dirty_super(const char *where, unsigned int line,
220 			      handle_t *handle, struct super_block *sb);
221 
222 #define ext4_journal_get_write_access(handle, bh) \
223 	__ext4_journal_get_write_access(__func__, __LINE__, (handle), (bh))
224 #define ext4_forget(handle, is_metadata, inode, bh, block_nr) \
225 	__ext4_forget(__func__, __LINE__, (handle), (is_metadata), (inode), \
226 		      (bh), (block_nr))
227 #define ext4_journal_get_create_access(handle, bh) \
228 	__ext4_journal_get_create_access(__func__, __LINE__, (handle), (bh))
229 #define ext4_handle_dirty_metadata(handle, inode, bh) \
230 	__ext4_handle_dirty_metadata(__func__, __LINE__, (handle), (inode), \
231 				     (bh))
232 #define ext4_handle_dirty_super(handle, sb) \
233 	__ext4_handle_dirty_super(__func__, __LINE__, (handle), (sb))
234 
235 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
236 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle);
237 
238 #define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)
239 
240 /* Note:  Do not use this for NULL handles.  This is only to determine if
241  * a properly allocated handle is using a journal or not. */
ext4_handle_valid(handle_t * handle)242 static inline int ext4_handle_valid(handle_t *handle)
243 {
244 	if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)
245 		return 0;
246 	return 1;
247 }
248 
ext4_handle_sync(handle_t * handle)249 static inline void ext4_handle_sync(handle_t *handle)
250 {
251 	if (ext4_handle_valid(handle))
252 		handle->h_sync = 1;
253 }
254 
ext4_handle_release_buffer(handle_t * handle,struct buffer_head * bh)255 static inline void ext4_handle_release_buffer(handle_t *handle,
256 						struct buffer_head *bh)
257 {
258 	if (ext4_handle_valid(handle))
259 		jbd2_journal_release_buffer(handle, bh);
260 }
261 
ext4_handle_is_aborted(handle_t * handle)262 static inline int ext4_handle_is_aborted(handle_t *handle)
263 {
264 	if (ext4_handle_valid(handle))
265 		return is_handle_aborted(handle);
266 	return 0;
267 }
268 
ext4_handle_has_enough_credits(handle_t * handle,int needed)269 static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
270 {
271 	if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
272 		return 0;
273 	return 1;
274 }
275 
ext4_journal_start(struct inode * inode,int nblocks)276 static inline handle_t *ext4_journal_start(struct inode *inode, int nblocks)
277 {
278 	return ext4_journal_start_sb(inode->i_sb, nblocks);
279 }
280 
281 #define ext4_journal_stop(handle) \
282 	__ext4_journal_stop(__func__, __LINE__, (handle))
283 
ext4_journal_current_handle(void)284 static inline handle_t *ext4_journal_current_handle(void)
285 {
286 	return journal_current_handle();
287 }
288 
ext4_journal_extend(handle_t * handle,int nblocks)289 static inline int ext4_journal_extend(handle_t *handle, int nblocks)
290 {
291 	if (ext4_handle_valid(handle))
292 		return jbd2_journal_extend(handle, nblocks);
293 	return 0;
294 }
295 
ext4_journal_restart(handle_t * handle,int nblocks)296 static inline int ext4_journal_restart(handle_t *handle, int nblocks)
297 {
298 	if (ext4_handle_valid(handle))
299 		return jbd2_journal_restart(handle, nblocks);
300 	return 0;
301 }
302 
ext4_journal_blocks_per_page(struct inode * inode)303 static inline int ext4_journal_blocks_per_page(struct inode *inode)
304 {
305 	if (EXT4_JOURNAL(inode) != NULL)
306 		return jbd2_journal_blocks_per_page(inode);
307 	return 0;
308 }
309 
ext4_journal_force_commit(journal_t * journal)310 static inline int ext4_journal_force_commit(journal_t *journal)
311 {
312 	if (journal)
313 		return jbd2_journal_force_commit(journal);
314 	return 0;
315 }
316 
ext4_jbd2_file_inode(handle_t * handle,struct inode * inode)317 static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
318 {
319 	if (ext4_handle_valid(handle))
320 		return jbd2_journal_file_inode(handle, EXT4_I(inode)->jinode);
321 	return 0;
322 }
323 
ext4_update_inode_fsync_trans(handle_t * handle,struct inode * inode,int datasync)324 static inline void ext4_update_inode_fsync_trans(handle_t *handle,
325 						 struct inode *inode,
326 						 int datasync)
327 {
328 	struct ext4_inode_info *ei = EXT4_I(inode);
329 
330 	if (ext4_handle_valid(handle)) {
331 		ei->i_sync_tid = handle->h_transaction->t_tid;
332 		if (datasync)
333 			ei->i_datasync_tid = handle->h_transaction->t_tid;
334 	}
335 }
336 
337 /* super.c */
338 int ext4_force_commit(struct super_block *sb);
339 
340 /*
341  * Ext4 inode journal modes
342  */
343 #define EXT4_INODE_JOURNAL_DATA_MODE	0x01 /* journal data mode */
344 #define EXT4_INODE_ORDERED_DATA_MODE	0x02 /* ordered data mode */
345 #define EXT4_INODE_WRITEBACK_DATA_MODE	0x04 /* writeback data mode */
346 
ext4_inode_journal_mode(struct inode * inode)347 static inline int ext4_inode_journal_mode(struct inode *inode)
348 {
349 	if (EXT4_JOURNAL(inode) == NULL)
350 		return EXT4_INODE_WRITEBACK_DATA_MODE;	/* writeback */
351 	/* We do not support data journalling with delayed allocation */
352 	if (!S_ISREG(inode->i_mode) ||
353 	    test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
354 		return EXT4_INODE_JOURNAL_DATA_MODE;	/* journal data */
355 	if (ext4_test_inode_flag(inode, EXT4_INODE_JOURNAL_DATA) &&
356 	    !test_opt(inode->i_sb, DELALLOC))
357 		return EXT4_INODE_JOURNAL_DATA_MODE;	/* journal data */
358 	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
359 		return EXT4_INODE_ORDERED_DATA_MODE;	/* ordered */
360 	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
361 		return EXT4_INODE_WRITEBACK_DATA_MODE;	/* writeback */
362 	else
363 		BUG();
364 }
365 
ext4_should_journal_data(struct inode * inode)366 static inline int ext4_should_journal_data(struct inode *inode)
367 {
368 	return ext4_inode_journal_mode(inode) & EXT4_INODE_JOURNAL_DATA_MODE;
369 }
370 
ext4_should_order_data(struct inode * inode)371 static inline int ext4_should_order_data(struct inode *inode)
372 {
373 	return ext4_inode_journal_mode(inode) & EXT4_INODE_ORDERED_DATA_MODE;
374 }
375 
ext4_should_writeback_data(struct inode * inode)376 static inline int ext4_should_writeback_data(struct inode *inode)
377 {
378 	return ext4_inode_journal_mode(inode) & EXT4_INODE_WRITEBACK_DATA_MODE;
379 }
380 
381 /*
382  * This function controls whether or not we should try to go down the
383  * dioread_nolock code paths, which makes it safe to avoid taking
384  * i_mutex for direct I/O reads.  This only works for extent-based
385  * files, and it doesn't work if data journaling is enabled, since the
386  * dioread_nolock code uses b_private to pass information back to the
387  * I/O completion handler, and this conflicts with the jbd's use of
388  * b_private.
389  */
ext4_should_dioread_nolock(struct inode * inode)390 static inline int ext4_should_dioread_nolock(struct inode *inode)
391 {
392 	if (!test_opt(inode->i_sb, DIOREAD_NOLOCK))
393 		return 0;
394 	if (!S_ISREG(inode->i_mode))
395 		return 0;
396 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
397 		return 0;
398 	if (ext4_should_journal_data(inode))
399 		return 0;
400 	return 1;
401 }
402 
403 #endif	/* _EXT4_JBD2_H */
404