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
10 int 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, EXT4_INODE_EA_INODE) ||
17 test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
18 (ext4_test_inode_flag(inode, 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 */
33 static 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 */
49 static 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 */
64 static 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
90 handle_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(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_creds,
113 GFP_NOFS, type, line);
114 }
115
116 int __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
143 handle_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 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(err);
159 }
160
161 err = jbd2_journal_start_reserved(handle, type, line);
162 if (err < 0)
163 return ERR_PTR(err);
164 return handle;
165 }
166
167 int __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, extend_cred, revoke_cred);
180 }
181
182 static 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, 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
207 static void ext4_check_bdev_write_error(struct super_block *sb)
208 {
209 struct address_space *mapping = sb->s_bdev->bd_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(&mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) {
220 spin_lock(&sbi->s_bdev_wb_lock);
221 err = errseq_check_and_advance(&mapping->wb_err, &sbi->s_bdev_wb_err);
222 spin_unlock(&sbi->s_bdev_wb_lock);
223 if (err)
224 ext4_error_err(sb, -err,
225 "Error while async write back metadata");
226 }
227 }
228
229 int __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 if (ext4_handle_valid(handle)) {
239 err = jbd2_journal_get_write_access(handle, bh);
240 if (err) {
241 ext4_journal_abort_handle(where, line, __func__, bh,
242 handle, err);
243 return err;
244 }
245 } else
246 ext4_check_bdev_write_error(sb);
247 if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
248 return 0;
249 BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
250 jbd2_journal_set_triggers(bh,
251 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
252 return 0;
253 }
254
255 /*
256 * The ext4 forget function must perform a revoke if we are freeing data
257 * which has been journaled. Metadata (eg. indirect blocks) must be
258 * revoked in all cases.
259 *
260 * "bh" may be NULL: a metadata block may have been freed from memory
261 * but there may still be a record of it in the journal, and that record
262 * still needs to be revoked.
263 */
264 int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
265 int is_metadata, struct inode *inode,
266 struct buffer_head *bh, ext4_fsblk_t blocknr)
267 {
268 int err;
269
270 might_sleep();
271
272 trace_ext4_forget(inode, is_metadata, blocknr);
273 BUFFER_TRACE(bh, "enter");
274
275 ext4_debug("forgetting bh %p: is_metadata=%d, mode %o, data mode %x\n",
276 bh, is_metadata, inode->i_mode,
277 test_opt(inode->i_sb, DATA_FLAGS));
278
279 /* In the no journal case, we can just do a bforget and return */
280 if (!ext4_handle_valid(handle)) {
281 bforget(bh);
282 return 0;
283 }
284
285 /* Never use the revoke function if we are doing full data
286 * journaling: there is no need to, and a V1 superblock won't
287 * support it. Otherwise, only skip the revoke on un-journaled
288 * data blocks. */
289
290 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
291 (!is_metadata && !ext4_should_journal_data(inode))) {
292 if (bh) {
293 BUFFER_TRACE(bh, "call jbd2_journal_forget");
294 err = jbd2_journal_forget(handle, bh);
295 if (err)
296 ext4_journal_abort_handle(where, line, __func__,
297 bh, handle, err);
298 return err;
299 }
300 return 0;
301 }
302
303 /*
304 * data!=journal && (is_metadata || should_journal_data(inode))
305 */
306 BUFFER_TRACE(bh, "call jbd2_journal_revoke");
307 err = jbd2_journal_revoke(handle, blocknr, bh);
308 if (err) {
309 ext4_journal_abort_handle(where, line, __func__,
310 bh, handle, err);
311 __ext4_error(inode->i_sb, where, line, true, -err, 0,
312 "error %d when attempting revoke", err);
313 }
314 BUFFER_TRACE(bh, "exit");
315 return err;
316 }
317
318 int __ext4_journal_get_create_access(const char *where, unsigned int line,
319 handle_t *handle, struct super_block *sb,
320 struct buffer_head *bh,
321 enum ext4_journal_trigger_type trigger_type)
322 {
323 int err;
324
325 if (!ext4_handle_valid(handle))
326 return 0;
327
328 err = jbd2_journal_get_create_access(handle, bh);
329 if (err) {
330 ext4_journal_abort_handle(where, line, __func__, bh, handle,
331 err);
332 return err;
333 }
334 if (trigger_type == EXT4_JTR_NONE || !ext4_has_metadata_csum(sb))
335 return 0;
336 BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
337 jbd2_journal_set_triggers(bh,
338 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
339 return 0;
340 }
341
342 int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
343 handle_t *handle, struct inode *inode,
344 struct buffer_head *bh)
345 {
346 int err = 0;
347
348 might_sleep();
349
350 set_buffer_meta(bh);
351 set_buffer_prio(bh);
352 set_buffer_uptodate(bh);
353 if (ext4_handle_valid(handle)) {
354 err = jbd2_journal_dirty_metadata(handle, bh);
355 /* Errors can only happen due to aborted journal or a nasty bug */
356 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
357 ext4_journal_abort_handle(where, line, __func__, bh,
358 handle, err);
359 if (inode == NULL) {
360 pr_err("EXT4: jbd2_journal_dirty_metadata "
361 "failed: handle type %u started at "
362 "line %u, credits %u/%u, errcode %d",
363 handle->h_type,
364 handle->h_line_no,
365 handle->h_requested_credits,
366 jbd2_handle_buffer_credits(handle), err);
367 return err;
368 }
369 ext4_error_inode(inode, where, line,
370 bh->b_blocknr,
371 "journal_dirty_metadata failed: "
372 "handle type %u started at line %u, "
373 "credits %u/%u, errcode %d",
374 handle->h_type,
375 handle->h_line_no,
376 handle->h_requested_credits,
377 jbd2_handle_buffer_credits(handle),
378 err);
379 }
380 } else {
381 if (inode)
382 mark_buffer_dirty_inode(bh, inode);
383 else
384 mark_buffer_dirty(bh);
385 if (inode && inode_needs_sync(inode)) {
386 sync_dirty_buffer(bh);
387 if (buffer_req(bh) && !buffer_uptodate(bh)) {
388 ext4_error_inode_err(inode, where, line,
389 bh->b_blocknr, EIO,
390 "IO error syncing itable block");
391 err = -EIO;
392 }
393 }
394 }
395 return err;
396 }
397
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