ext4_jbd2.c

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