1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Interface between ext4 and JBD
4 */
5
6#include "ext4_jbd2.h"
7
8#include <trace/events/ext4.h>
9
10int ext4_inode_journal_mode(struct inode *inode)
11{
12 if (EXT4_JOURNAL(inode) == NULL)
13 return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */
14 /* We do not support data journalling with delayed allocation */
15 if (!S_ISREG(inode->i_mode) ||
16 ext4_test_inode_flag(inode, bit: EXT4_INODE_EA_INODE) ||
17 test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
18 (ext4_test_inode_flag(inode, bit: EXT4_INODE_JOURNAL_DATA) &&
19 !test_opt(inode->i_sb, DELALLOC))) {
20 /* We do not support data journalling for encrypted data */
21 if (S_ISREG(inode->i_mode) && IS_ENCRYPTED(inode))
22 return EXT4_INODE_ORDERED_DATA_MODE; /* ordered */
23 return EXT4_INODE_JOURNAL_DATA_MODE; /* journal data */
24 }
25 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
26 return EXT4_INODE_ORDERED_DATA_MODE; /* ordered */
27 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
28 return EXT4_INODE_WRITEBACK_DATA_MODE; /* writeback */
29 BUG();
30}
31
32/* Just increment the non-pointer handle value */
33static handle_t *ext4_get_nojournal(void)
34{
35 handle_t *handle = current->journal_info;
36 unsigned long ref_cnt = (unsigned long)handle;
37
38 BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
39
40 ref_cnt++;
41 handle = (handle_t *)ref_cnt;
42
43 current->journal_info = handle;
44 return handle;
45}
46
47
48/* Decrement the non-pointer handle value */
49static void ext4_put_nojournal(handle_t *handle)
50{
51 unsigned long ref_cnt = (unsigned long)handle;
52
53 BUG_ON(ref_cnt == 0);
54
55 ref_cnt--;
56 handle = (handle_t *)ref_cnt;
57
58 current->journal_info = handle;
59}
60
61/*
62 * Wrappers for jbd2_journal_start/end.
63 */
64static int ext4_journal_check_start(struct super_block *sb)
65{
66 journal_t *journal;
67
68 might_sleep();
69
70 if (unlikely(ext4_forced_shutdown(sb)))
71 return -EIO;
72
73 if (WARN_ON_ONCE(sb_rdonly(sb)))
74 return -EROFS;
75
76 WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
77 journal = EXT4_SB(sb)->s_journal;
78 /*
79 * Special case here: if the journal has aborted behind our
80 * backs (eg. EIO in the commit thread), then we still need to
81 * take the FS itself readonly cleanly.
82 */
83 if (journal && is_journal_aborted(journal)) {
84 ext4_abort(sb, -journal->j_errno, "Detected aborted journal");
85 return -EROFS;
86 }
87 return 0;
88}
89
90handle_t *__ext4_journal_start_sb(struct inode *inode,
91 struct super_block *sb, unsigned int line,
92 int type, int blocks, int rsv_blocks,
93 int revoke_creds)
94{
95 journal_t *journal;
96 int err;
97 if (inode)
98 trace_ext4_journal_start_inode(inode, blocks, rsv_blocks,
99 revoke_creds, type,
100 _RET_IP_);
101 else
102 trace_ext4_journal_start_sb(sb, blocks, rsv_blocks,
103 revoke_creds, type,
104 _RET_IP_);
105 err = ext4_journal_check_start(sb);
106 if (err < 0)
107 return ERR_PTR(error: err);
108
109 journal = EXT4_SB(sb)->s_journal;
110 if (!journal || (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
111 return ext4_get_nojournal();
112 return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_records: revoke_creds,
113 GFP_NOFS, type, line_no: line);
114}
115
116int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
117{
118 struct super_block *sb;
119 int err;
120 int rc;
121
122 if (!ext4_handle_valid(handle)) {
123 ext4_put_nojournal(handle);
124 return 0;
125 }
126
127 err = handle->h_err;
128 if (!handle->h_transaction) {
129 rc = jbd2_journal_stop(handle);
130 return err ? err : rc;
131 }
132
133 sb = handle->h_transaction->t_journal->j_private;
134 rc = jbd2_journal_stop(handle);
135
136 if (!err)
137 err = rc;
138 if (err)
139 __ext4_std_error(sb, where, line, err);
140 return err;
141}
142
143handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
144 int type)
145{
146 struct super_block *sb;
147 int err;
148
149 if (!ext4_handle_valid(handle))
150 return ext4_get_nojournal();
151
152 sb = handle->h_journal->j_private;
153 trace_ext4_journal_start_reserved(sb,
154 blocks: jbd2_handle_buffer_credits(handle), _RET_IP_);
155 err = ext4_journal_check_start(sb);
156 if (err < 0) {
157 jbd2_journal_free_reserved(handle);
158 return ERR_PTR(error: err);
159 }
160
161 err = jbd2_journal_start_reserved(handle, type, line_no: line);
162 if (err < 0)
163 return ERR_PTR(error: err);
164 return handle;
165}
166
167int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
168 int extend_cred, int revoke_cred)
169{
170 if (!ext4_handle_valid(handle))
171 return 0;
172 if (is_handle_aborted(handle))
173 return -EROFS;
174 if (jbd2_handle_buffer_credits(handle) >= check_cred &&
175 handle->h_revoke_credits >= revoke_cred)
176 return 0;
177 extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle));
178 revoke_cred = max(0, revoke_cred - handle->h_revoke_credits);
179 return ext4_journal_extend(handle, nblocks: extend_cred, revoke: revoke_cred);
180}
181
182static void ext4_journal_abort_handle(const char *caller, unsigned int line,
183 const char *err_fn,
184 struct buffer_head *bh,
185 handle_t *handle, int err)
186{
187 char nbuf[16];
188 const char *errstr = ext4_decode_error(NULL, errno: err, nbuf);
189
190 BUG_ON(!ext4_handle_valid(handle));
191
192 if (bh)
193 BUFFER_TRACE(bh, "abort");
194
195 if (!handle->h_err)
196 handle->h_err = err;
197
198 if (is_handle_aborted(handle))
199 return;
200
201 printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
202 caller, line, errstr, err_fn);
203
204 jbd2_journal_abort_handle(handle);
205}
206
207static void ext4_check_bdev_write_error(struct super_block *sb)
208{
209 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
210 struct ext4_sb_info *sbi = EXT4_SB(sb);
211 int err;
212
213 /*
214 * If the block device has write error flag, it may have failed to
215 * async write out metadata buffers in the background. In this case,
216 * we could read old data from disk and write it out again, which
217 * may lead to on-disk filesystem inconsistency.
218 */
219 if (errseq_check(eseq: &mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) {
220 spin_lock(lock: &sbi->s_bdev_wb_lock);
221 err = errseq_check_and_advance(eseq: &mapping->wb_err, since: &sbi->s_bdev_wb_err);
222 spin_unlock(lock: &sbi->s_bdev_wb_lock);
223 if (err)
224 ext4_error_err(sb, -err,
225 "Error while async write back metadata");
226 }
227}
228
229int __ext4_journal_get_write_access(const char *where, unsigned int line,
230 handle_t *handle, struct super_block *sb,
231 struct buffer_head *bh,
232 enum ext4_journal_trigger_type trigger_type)
233{
234 int err;
235
236 might_sleep();
237
238 ext4_check_bdev_write_error(sb);
239
240 if (ext4_handle_valid(handle)) {
241 err = jbd2_journal_get_write_access(handle, bh);
242 if (err) {
243 ext4_journal_abort_handle(caller: where, line, err_fn: __func__, bh,
244 handle, err);
245 return err;
246 }
247 }
248 if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
249 return 0;
250 BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
251 jbd2_journal_set_triggers(bh,
252 type: &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
253 return 0;
254}
255
256/*
257 * The ext4 forget function must perform a revoke if we are freeing data
258 * which has been journaled. Metadata (eg. indirect blocks) must be
259 * revoked in all cases.
260 *
261 * "bh" may be NULL: a metadata block may have been freed from memory
262 * but there may still be a record of it in the journal, and that record
263 * still needs to be revoked.
264 */
265int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
266 int is_metadata, struct inode *inode,
267 struct buffer_head *bh, ext4_fsblk_t blocknr)
268{
269 int err;
270
271 might_sleep();
272
273 trace_ext4_forget(inode, is_metadata, block: blocknr);
274 BUFFER_TRACE(bh, "enter");
275
276 ext4_debug("forgetting bh %p: is_metadata=%d, mode %o, data mode %x\n",
277 bh, is_metadata, inode->i_mode,
278 test_opt(inode->i_sb, DATA_FLAGS));
279
280 /* In the no journal case, we can just do a bforget and return */
281 if (!ext4_handle_valid(handle)) {
282 bforget(bh);
283 return 0;
284 }
285
286 /* Never use the revoke function if we are doing full data
287 * journaling: there is no need to, and a V1 superblock won't
288 * support it. Otherwise, only skip the revoke on un-journaled
289 * data blocks. */
290
291 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
292 (!is_metadata && !ext4_should_journal_data(inode))) {
293 if (bh) {
294 BUFFER_TRACE(bh, "call jbd2_journal_forget");
295 err = jbd2_journal_forget(handle, bh);
296 if (err)
297 ext4_journal_abort_handle(caller: where, line, err_fn: __func__,
298 bh, handle, err);
299 return err;
300 }
301 return 0;
302 }
303
304 /*
305 * data!=journal && (is_metadata || should_journal_data(inode))
306 */
307 BUFFER_TRACE(bh, "call jbd2_journal_revoke");
308 err = jbd2_journal_revoke(handle, blocknr, bh);
309 if (err) {
310 ext4_journal_abort_handle(caller: where, line, err_fn: __func__,
311 bh, handle, err);
312 __ext4_error(inode->i_sb, where, line, true, -err, 0,
313 "error %d when attempting revoke", err);
314 }
315 BUFFER_TRACE(bh, "exit");
316 return err;
317}
318
319int __ext4_journal_get_create_access(const char *where, unsigned int line,
320 handle_t *handle, struct super_block *sb,
321 struct buffer_head *bh,
322 enum ext4_journal_trigger_type trigger_type)
323{
324 int err;
325
326 if (!ext4_handle_valid(handle))
327 return 0;
328
329 err = jbd2_journal_get_create_access(handle, bh);
330 if (err) {
331 ext4_journal_abort_handle(caller: where, line, err_fn: __func__, bh, handle,
332 err);
333 return err;
334 }
335 if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
336 return 0;
337 BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
338 jbd2_journal_set_triggers(bh,
339 type: &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
340 return 0;
341}
342
343int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
344 handle_t *handle, struct inode *inode,
345 struct buffer_head *bh)
346{
347 int err = 0;
348
349 might_sleep();
350
351 set_buffer_meta(bh);
352 set_buffer_prio(bh);
353 set_buffer_uptodate(bh);
354 if (ext4_handle_valid(handle)) {
355 err = jbd2_journal_dirty_metadata(handle, bh);
356 /* Errors can only happen due to aborted journal or a nasty bug */
357 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
358 ext4_journal_abort_handle(caller: where, line, err_fn: __func__, bh,
359 handle, err);
360 if (inode == NULL) {
361 pr_err("EXT4: jbd2_journal_dirty_metadata "
362 "failed: handle type %u started at "
363 "line %u, credits %u/%u, errcode %d",
364 handle->h_type,
365 handle->h_line_no,
366 handle->h_requested_credits,
367 jbd2_handle_buffer_credits(handle), err);
368 return err;
369 }
370 ext4_error_inode(inode, where, line,
371 bh->b_blocknr,
372 "journal_dirty_metadata failed: "
373 "handle type %u started at line %u, "
374 "credits %u/%u, errcode %d",
375 handle->h_type,
376 handle->h_line_no,
377 handle->h_requested_credits,
378 jbd2_handle_buffer_credits(handle),
379 err);
380 }
381 } else {
382 if (inode)
383 mark_buffer_dirty_inode(bh, inode);
384 else
385 mark_buffer_dirty(bh);
386 if (inode && inode_needs_sync(inode)) {
387 sync_dirty_buffer(bh);
388 if (buffer_req(bh) && !buffer_uptodate(bh)) {
389 ext4_error_inode_err(inode, where, line,
390 bh->b_blocknr, EIO,
391 "IO error syncing itable block");
392 err = -EIO;
393 }
394 }
395 }
396 return err;
397}
398

source code of linux/fs/ext4/ext4_jbd2.c