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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, 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 */
33static handle_t *ext4_get_nojournal(void)
34{
35 handle_t *handle = current->journal_info;
36
37 BUG_ON(handle && !handle->h_invalid);
38
39 if (!handle) {
40 handle = jbd2_alloc_handle(GFP_NOFS);
41 if (!handle)
42 return ERR_PTR(-ENOMEM);
43 handle->h_invalid = 1;
44 /*
45 * This is done by start_this_handle() if journalling
46 * is enabled.
47 */
48 handle->saved_alloc_context = memalloc_nofs_save();
49 current->journal_info = handle;
50 }
51 handle->h_ref++;
52 return handle;
53}
54
55
56/* Decrement the non-pointer handle value */
57static void ext4_put_nojournal(handle_t *handle)
58{
59 BUG_ON(handle->h_ref == 0);
60
61 handle->h_ref--;
62 if (handle->h_ref == 0) {
63 memalloc_nofs_restore(handle->saved_alloc_context);
64 jbd2_free_handle(handle);
65 current->journal_info = NULL;
66 }
67}
68
69/*
70 * Wrappers for jbd2_journal_start/end.
71 */
72static int ext4_journal_check_start(struct super_block *sb)
73{
74 int ret;
75 journal_t *journal;
76
77 might_sleep();
78
79 ret = ext4_emergency_state(sb);
80 if (unlikely(ret))
81 return ret;
82
83 if (WARN_ON_ONCE(sb_rdonly(sb)))
84 return -EROFS;
85
86 WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
87 journal = EXT4_SB(sb)->s_journal;
88 /*
89 * Special case here: if the journal has aborted behind our
90 * backs (eg. EIO in the commit thread), then we still need to
91 * take the FS itself readonly cleanly.
92 */
93 if (journal && is_journal_aborted(journal)) {
94 ext4_abort(sb, -journal->j_errno, "Detected aborted journal");
95 return -EROFS;
96 }
97 return 0;
98}
99
100handle_t *__ext4_journal_start_sb(struct inode *inode,
101 struct super_block *sb, unsigned int line,
102 int type, int blocks, int rsv_blocks,
103 int revoke_creds)
104{
105 journal_t *journal;
106 int err;
107 if (inode)
108 trace_ext4_journal_start_inode(inode, blocks, rsv_blocks,
109 revoke_creds, type,
110 _RET_IP_);
111 else
112 trace_ext4_journal_start_sb(sb, blocks, rsv_blocks,
113 revoke_creds, type,
114 _RET_IP_);
115 err = ext4_journal_check_start(sb);
116 if (err < 0)
117 return ERR_PTR(err);
118
119 journal = EXT4_SB(sb)->s_journal;
120 if (!journal || (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
121 return ext4_get_nojournal();
122 return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds,
123 GFP_NOFS, type, line);
124}
125
126int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
127{
128 struct super_block *sb;
129 int err;
130 int rc;
131
132 if (!ext4_handle_valid(handle)) {
133 ext4_put_nojournal(handle);
134 return 0;
135 }
136
137 err = handle->h_err;
138 if (!handle->h_transaction) {
139 rc = jbd2_journal_stop(handle);
140 return err ? err : rc;
141 }
142
143 sb = handle->h_transaction->t_journal->j_private;
144 rc = jbd2_journal_stop(handle);
145
146 if (!err)
147 err = rc;
148 if (err)
149 __ext4_std_error(sb, where, line, err);
150 return err;
151}
152
153handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
154 int type)
155{
156 struct super_block *sb;
157 int err;
158
159 if (!ext4_handle_valid(handle))
160 return ext4_get_nojournal();
161
162 sb = handle->h_journal->j_private;
163 trace_ext4_journal_start_reserved(sb,
164 jbd2_handle_buffer_credits(handle), _RET_IP_);
165 err = ext4_journal_check_start(sb);
166 if (err < 0) {
167 jbd2_journal_free_reserved(handle);
168 return ERR_PTR(err);
169 }
170
171 err = jbd2_journal_start_reserved(handle, type, line);
172 if (err < 0)
173 return ERR_PTR(err);
174 return handle;
175}
176
177int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
178 int extend_cred, int revoke_cred)
179{
180 if (!ext4_handle_valid(handle))
181 return 0;
182 if (is_handle_aborted(handle))
183 return -EROFS;
184 if (jbd2_handle_buffer_credits(handle) >= check_cred &&
185 handle->h_revoke_credits >= revoke_cred)
186 return 0;
187 extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle));
188 revoke_cred = max(0, revoke_cred - handle->h_revoke_credits);
189 return ext4_journal_extend(handle, extend_cred, revoke_cred);
190}
191
192static void ext4_journal_abort_handle(const char *caller, unsigned int line,
193 const char *err_fn,
194 struct buffer_head *bh,
195 handle_t *handle, int err)
196{
197 char nbuf[16];
198 const char *errstr = ext4_decode_error(NULL, err, nbuf);
199
200 BUG_ON(!ext4_handle_valid(handle));
201
202 if (bh)
203 BUFFER_TRACE(bh, "abort");
204
205 if (!handle->h_err)
206 handle->h_err = err;
207
208 if (is_handle_aborted(handle))
209 return;
210
211 printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
212 caller, line, errstr, err_fn);
213
214 jbd2_journal_abort_handle(handle);
215}
216
217static void ext4_check_bdev_write_error(struct super_block *sb)
218{
219 struct address_space *mapping = sb->s_bdev->bd_mapping;
220 struct ext4_sb_info *sbi = EXT4_SB(sb);
221 int err;
222
223 /*
224 * If the block device has write error flag, it may have failed to
225 * async write out metadata buffers in the background. In this case,
226 * we could read old data from disk and write it out again, which
227 * may lead to on-disk filesystem inconsistency.
228 */
229 if (errseq_check(&mapping->wb_err, READ_ONCE(sbi->s_bdev_wb_err))) {
230 spin_lock(&sbi->s_bdev_wb_lock);
231 err = errseq_check_and_advance(&mapping->wb_err, &sbi->s_bdev_wb_err);
232 spin_unlock(&sbi->s_bdev_wb_lock);
233 if (err)
234 ext4_error_err(sb, -err,
235 "Error while async write back metadata");
236 }
237}
238
239int __ext4_journal_get_write_access(const char *where, unsigned int line,
240 handle_t *handle, struct super_block *sb,
241 struct buffer_head *bh,
242 enum ext4_journal_trigger_type trigger_type)
243{
244 int err;
245
246 might_sleep();
247
248 if (ext4_handle_valid(handle)) {
249 err = jbd2_journal_get_write_access(handle, bh);
250 if (err) {
251 ext4_journal_abort_handle(where, line, __func__, bh,
252 handle, err);
253 return err;
254 }
255 } else
256 ext4_check_bdev_write_error(sb);
257 if (trigger_type == EXT4_JTR_NONE ||
258 !ext4_has_feature_metadata_csum(sb))
259 return 0;
260 BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
261 jbd2_journal_set_triggers(bh,
262 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
263 return 0;
264}
265
266/*
267 * The ext4 forget function must perform a revoke if we are freeing data
268 * which has been journaled. Metadata (eg. indirect blocks) must be
269 * revoked in all cases.
270 *
271 * "bh" may be NULL: a metadata block may have been freed from memory
272 * but there may still be a record of it in the journal, and that record
273 * still needs to be revoked.
274 */
275int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
276 int is_metadata, struct inode *inode,
277 struct buffer_head *bh, ext4_fsblk_t blocknr)
278{
279 int err;
280
281 might_sleep();
282
283 trace_ext4_forget(inode, is_metadata, blocknr);
284 BUFFER_TRACE(bh, "enter");
285
286 ext4_debug("forgetting bh %p: is_metadata=%d, mode %o, data mode %x\n",
287 bh, is_metadata, inode->i_mode,
288 test_opt(inode->i_sb, DATA_FLAGS));
289
290 /*
291 * In the no journal case, we should wait for the ongoing buffer
292 * to complete and do a forget.
293 */
294 if (!ext4_handle_valid(handle)) {
295 if (bh) {
296 clear_buffer_dirty(bh);
297 wait_on_buffer(bh);
298 __bforget(bh);
299 }
300 return 0;
301 }
302
303 /* Never use the revoke function if we are doing full data
304 * journaling: there is no need to, and a V1 superblock won't
305 * support it. Otherwise, only skip the revoke on un-journaled
306 * data blocks. */
307
308 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
309 (!is_metadata && !ext4_should_journal_data(inode))) {
310 if (bh) {
311 BUFFER_TRACE(bh, "call jbd2_journal_forget");
312 err = jbd2_journal_forget(handle, bh);
313 if (err)
314 ext4_journal_abort_handle(where, line, __func__,
315 bh, handle, err);
316 return err;
317 }
318 return 0;
319 }
320
321 /*
322 * data!=journal && (is_metadata || should_journal_data(inode))
323 */
324 BUFFER_TRACE(bh, "call jbd2_journal_revoke");
325 err = jbd2_journal_revoke(handle, blocknr, bh);
326 if (err) {
327 ext4_journal_abort_handle(where, line, __func__,
328 bh, handle, err);
329 __ext4_error(inode->i_sb, where, line, true, -err, 0,
330 "error %d when attempting revoke", err);
331 }
332 BUFFER_TRACE(bh, "exit");
333 return err;
334}
335
336int __ext4_journal_get_create_access(const char *where, unsigned int line,
337 handle_t *handle, struct super_block *sb,
338 struct buffer_head *bh,
339 enum ext4_journal_trigger_type trigger_type)
340{
341 int err;
342
343 if (!ext4_handle_valid(handle))
344 return 0;
345
346 err = jbd2_journal_get_create_access(handle, bh);
347 if (err) {
348 ext4_journal_abort_handle(where, line, __func__, bh, handle,
349 err);
350 return err;
351 }
352 if (trigger_type == EXT4_JTR_NONE ||
353 !ext4_has_feature_metadata_csum(sb))
354 return 0;
355 BUG_ON(trigger_type >= EXT4_JOURNAL_TRIGGER_COUNT);
356 jbd2_journal_set_triggers(bh,
357 &EXT4_SB(sb)->s_journal_triggers[trigger_type].tr_triggers);
358 return 0;
359}
360
361static void ext4_inode_attach_mmb(struct inode *inode)
362{
363 struct mapping_metadata_bhs *mmb;
364
365 /*
366 * It's difficult to handle failure when marking buffer dirty without
367 * leaving filesystem corrupted
368 */
369 mmb = kmalloc_obj(*mmb, GFP_NOFS | __GFP_NOFAIL | __GFP_ACCOUNT);
370 mmb_init(mmb, &inode->i_data);
371 /* Someone swapped another mmb before us? */
372 if (cmpxchg(&EXT4_I(inode)->i_metadata_bhs, NULL, mmb))
373 kfree(mmb);
374}
375
376int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
377 handle_t *handle, struct inode *inode,
378 struct buffer_head *bh)
379{
380 int err = 0;
381
382 might_sleep();
383
384 set_buffer_meta(bh);
385 set_buffer_prio(bh);
386 set_buffer_uptodate(bh);
387 if (ext4_handle_valid(handle)) {
388 err = jbd2_journal_dirty_metadata(handle, bh);
389 /* Errors can only happen due to aborted journal or a nasty bug */
390 if (!is_handle_aborted(handle) && WARN_ON_ONCE(err)) {
391 ext4_journal_abort_handle(where, line, __func__, bh,
392 handle, err);
393 if (inode == NULL) {
394 pr_err("EXT4: jbd2_journal_dirty_metadata "
395 "failed: handle type %u started at "
396 "line %u, credits %u/%u, errcode %d",
397 handle->h_type,
398 handle->h_line_no,
399 handle->h_requested_credits,
400 jbd2_handle_buffer_credits(handle), err);
401 return err;
402 }
403 ext4_error_inode(inode, where, line,
404 bh->b_blocknr,
405 "journal_dirty_metadata failed: "
406 "handle type %u started at line %u, "
407 "credits %u/%u, errcode %d",
408 handle->h_type,
409 handle->h_line_no,
410 handle->h_requested_credits,
411 jbd2_handle_buffer_credits(handle),
412 err);
413 }
414 } else {
415 if (inode) {
416 if (!ext4_i_metadata_bhs(inode))
417 ext4_inode_attach_mmb(inode);
418 mmb_mark_buffer_dirty(bh, ext4_i_metadata_bhs(inode));
419 } else {
420 mark_buffer_dirty(bh);
421 }
422 if (inode && inode_needs_sync(inode)) {
423 sync_dirty_buffer(bh);
424 if (buffer_write_io_error(bh)) {
425 ext4_error_inode_err(inode, where, line,
426 bh->b_blocknr, EIO,
427 "IO error syncing itable block");
428 err = -EIO;
429 }
430 }
431 }
432 return err;
433}