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	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(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
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				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
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, extend_cred, 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, 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(&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
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	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 */
264int __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
318int __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
342int __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