2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 #include "xfs_types.h"
23 #include "xfs_trans.h"
26 #include "xfs_mount.h"
27 #include "xfs_buf_item.h"
28 #include "xfs_trans_priv.h"
29 #include "xfs_error.h"
30 #include "xfs_trace.h"
33 kmem_zone_t
*xfs_buf_item_zone
;
35 static inline struct xfs_buf_log_item
*BUF_ITEM(struct xfs_log_item
*lip
)
37 return container_of(lip
, struct xfs_buf_log_item
, bli_item
);
40 STATIC
void xfs_buf_do_callbacks(struct xfs_buf
*bp
);
43 * This returns the number of log iovecs needed to log the
46 * It calculates this as 1 iovec for the buf log format structure
47 * and 1 for each stretch of non-contiguous chunks to be logged.
48 * Contiguous chunks are logged in a single iovec.
50 * If the XFS_BLI_STALE flag has been set, then log nothing.
53 xfs_buf_item_size_segment(
54 struct xfs_buf_log_item
*bip
,
55 struct xfs_buf_log_format
*blfp
)
57 struct xfs_buf
*bp
= bip
->bli_buf
;
62 last_bit
= xfs_next_bit(blfp
->blf_data_map
, blfp
->blf_map_size
, 0);
67 * initial count for a dirty buffer is 2 vectors - the format structure
68 * and the first dirty region.
72 while (last_bit
!= -1) {
74 * This takes the bit number to start looking from and
75 * returns the next set bit from there. It returns -1
76 * if there are no more bits set or the start bit is
77 * beyond the end of the bitmap.
79 next_bit
= xfs_next_bit(blfp
->blf_data_map
, blfp
->blf_map_size
,
82 * If we run out of bits, leave the loop,
83 * else if we find a new set of bits bump the number of vecs,
84 * else keep scanning the current set of bits.
88 } else if (next_bit
!= last_bit
+ 1) {
91 } else if (xfs_buf_offset(bp
, next_bit
* XFS_BLF_CHUNK
) !=
92 (xfs_buf_offset(bp
, last_bit
* XFS_BLF_CHUNK
) +
105 * This returns the number of log iovecs needed to log the given buf log item.
107 * It calculates this as 1 iovec for the buf log format structure and 1 for each
108 * stretch of non-contiguous chunks to be logged. Contiguous chunks are logged
111 * Discontiguous buffers need a format structure per region that that is being
112 * logged. This makes the changes in the buffer appear to log recovery as though
113 * they came from separate buffers, just like would occur if multiple buffers
114 * were used instead of a single discontiguous buffer. This enables
115 * discontiguous buffers to be in-memory constructs, completely transparent to
116 * what ends up on disk.
118 * If the XFS_BLI_STALE flag has been set, then log nothing but the buf log
123 struct xfs_log_item
*lip
)
125 struct xfs_buf_log_item
*bip
= BUF_ITEM(lip
);
129 ASSERT(atomic_read(&bip
->bli_refcount
) > 0);
130 if (bip
->bli_flags
& XFS_BLI_STALE
) {
132 * The buffer is stale, so all we need to log
133 * is the buf log format structure with the
136 trace_xfs_buf_item_size_stale(bip
);
137 ASSERT(bip
->__bli_format
.blf_flags
& XFS_BLF_CANCEL
);
138 return bip
->bli_format_count
;
141 ASSERT(bip
->bli_flags
& XFS_BLI_LOGGED
);
144 * the vector count is based on the number of buffer vectors we have
145 * dirty bits in. This will only be greater than one when we have a
146 * compound buffer with more than one segment dirty. Hence for compound
147 * buffers we need to track which segment the dirty bits correspond to,
148 * and when we move from one segment to the next increment the vector
149 * count for the extra buf log format structure that will need to be
153 for (i
= 0; i
< bip
->bli_format_count
; i
++) {
154 nvecs
+= xfs_buf_item_size_segment(bip
, &bip
->bli_formats
[i
]);
157 trace_xfs_buf_item_size(bip
);
161 static struct xfs_log_iovec
*
162 xfs_buf_item_format_segment(
163 struct xfs_buf_log_item
*bip
,
164 struct xfs_log_iovec
*vecp
,
166 struct xfs_buf_log_format
*blfp
)
168 struct xfs_buf
*bp
= bip
->bli_buf
;
177 /* copy the flags across from the base format item */
178 blfp
->blf_flags
= bip
->__bli_format
.blf_flags
;
181 * Base size is the actual size of the ondisk structure - it reflects
182 * the actual size of the dirty bitmap rather than the size of the in
185 base_size
= offsetof(struct xfs_buf_log_format
, blf_data_map
) +
186 (blfp
->blf_map_size
* sizeof(blfp
->blf_data_map
[0]));
189 first_bit
= xfs_next_bit(blfp
->blf_data_map
, blfp
->blf_map_size
, 0);
190 if (!(bip
->bli_flags
& XFS_BLI_STALE
) && first_bit
== -1) {
192 * If the map is not be dirty in the transaction, mark
193 * the size as zero and do not advance the vector pointer.
199 vecp
->i_len
= base_size
;
200 vecp
->i_type
= XLOG_REG_TYPE_BFORMAT
;
204 if (bip
->bli_flags
& XFS_BLI_STALE
) {
206 * The buffer is stale, so all we need to log
207 * is the buf log format structure with the
210 trace_xfs_buf_item_format_stale(bip
);
211 ASSERT(blfp
->blf_flags
& XFS_BLF_CANCEL
);
216 * Fill in an iovec for each set of contiguous chunks.
219 last_bit
= first_bit
;
223 * This takes the bit number to start looking from and
224 * returns the next set bit from there. It returns -1
225 * if there are no more bits set or the start bit is
226 * beyond the end of the bitmap.
228 next_bit
= xfs_next_bit(blfp
->blf_data_map
, blfp
->blf_map_size
,
231 * If we run out of bits fill in the last iovec and get
233 * Else if we start a new set of bits then fill in the
234 * iovec for the series we were looking at and start
235 * counting the bits in the new one.
236 * Else we're still in the same set of bits so just
237 * keep counting and scanning.
239 if (next_bit
== -1) {
240 buffer_offset
= offset
+ first_bit
* XFS_BLF_CHUNK
;
241 vecp
->i_addr
= xfs_buf_offset(bp
, buffer_offset
);
242 vecp
->i_len
= nbits
* XFS_BLF_CHUNK
;
243 vecp
->i_type
= XLOG_REG_TYPE_BCHUNK
;
246 } else if (next_bit
!= last_bit
+ 1) {
247 buffer_offset
= offset
+ first_bit
* XFS_BLF_CHUNK
;
248 vecp
->i_addr
= xfs_buf_offset(bp
, buffer_offset
);
249 vecp
->i_len
= nbits
* XFS_BLF_CHUNK
;
250 vecp
->i_type
= XLOG_REG_TYPE_BCHUNK
;
253 first_bit
= next_bit
;
256 } else if (xfs_buf_offset(bp
, offset
+
257 (next_bit
<< XFS_BLF_SHIFT
)) !=
258 (xfs_buf_offset(bp
, offset
+
259 (last_bit
<< XFS_BLF_SHIFT
)) +
261 buffer_offset
= offset
+ first_bit
* XFS_BLF_CHUNK
;
262 vecp
->i_addr
= xfs_buf_offset(bp
, buffer_offset
);
263 vecp
->i_len
= nbits
* XFS_BLF_CHUNK
;
264 vecp
->i_type
= XLOG_REG_TYPE_BCHUNK
;
267 first_bit
= next_bit
;
276 blfp
->blf_size
= nvecs
;
281 * This is called to fill in the vector of log iovecs for the
282 * given log buf item. It fills the first entry with a buf log
283 * format structure, and the rest point to contiguous chunks
288 struct xfs_log_item
*lip
,
289 struct xfs_log_iovec
*vecp
)
291 struct xfs_buf_log_item
*bip
= BUF_ITEM(lip
);
292 struct xfs_buf
*bp
= bip
->bli_buf
;
296 ASSERT(atomic_read(&bip
->bli_refcount
) > 0);
297 ASSERT((bip
->bli_flags
& XFS_BLI_LOGGED
) ||
298 (bip
->bli_flags
& XFS_BLI_STALE
));
301 * If it is an inode buffer, transfer the in-memory state to the
302 * format flags and clear the in-memory state. We do not transfer
303 * this state if the inode buffer allocation has not yet been committed
304 * to the log as setting the XFS_BLI_INODE_BUF flag will prevent
305 * correct replay of the inode allocation.
307 if (bip
->bli_flags
& XFS_BLI_INODE_BUF
) {
308 if (!((bip
->bli_flags
& XFS_BLI_INODE_ALLOC_BUF
) &&
309 xfs_log_item_in_current_chkpt(lip
)))
310 bip
->__bli_format
.blf_flags
|= XFS_BLF_INODE_BUF
;
311 bip
->bli_flags
&= ~XFS_BLI_INODE_BUF
;
314 for (i
= 0; i
< bip
->bli_format_count
; i
++) {
315 vecp
= xfs_buf_item_format_segment(bip
, vecp
, offset
,
316 &bip
->bli_formats
[i
]);
317 offset
+= bp
->b_maps
[i
].bm_len
;
321 * Check to make sure everything is consistent.
323 trace_xfs_buf_item_format(bip
);
327 * This is called to pin the buffer associated with the buf log item in memory
328 * so it cannot be written out.
330 * We also always take a reference to the buffer log item here so that the bli
331 * is held while the item is pinned in memory. This means that we can
332 * unconditionally drop the reference count a transaction holds when the
333 * transaction is completed.
337 struct xfs_log_item
*lip
)
339 struct xfs_buf_log_item
*bip
= BUF_ITEM(lip
);
341 ASSERT(atomic_read(&bip
->bli_refcount
) > 0);
342 ASSERT((bip
->bli_flags
& XFS_BLI_LOGGED
) ||
343 (bip
->bli_flags
& XFS_BLI_STALE
));
345 trace_xfs_buf_item_pin(bip
);
347 atomic_inc(&bip
->bli_refcount
);
348 atomic_inc(&bip
->bli_buf
->b_pin_count
);
352 * This is called to unpin the buffer associated with the buf log
353 * item which was previously pinned with a call to xfs_buf_item_pin().
355 * Also drop the reference to the buf item for the current transaction.
356 * If the XFS_BLI_STALE flag is set and we are the last reference,
357 * then free up the buf log item and unlock the buffer.
359 * If the remove flag is set we are called from uncommit in the
360 * forced-shutdown path. If that is true and the reference count on
361 * the log item is going to drop to zero we need to free the item's
362 * descriptor in the transaction.
366 struct xfs_log_item
*lip
,
369 struct xfs_buf_log_item
*bip
= BUF_ITEM(lip
);
370 xfs_buf_t
*bp
= bip
->bli_buf
;
371 struct xfs_ail
*ailp
= lip
->li_ailp
;
372 int stale
= bip
->bli_flags
& XFS_BLI_STALE
;
375 ASSERT(bp
->b_fspriv
== bip
);
376 ASSERT(atomic_read(&bip
->bli_refcount
) > 0);
378 trace_xfs_buf_item_unpin(bip
);
380 freed
= atomic_dec_and_test(&bip
->bli_refcount
);
382 if (atomic_dec_and_test(&bp
->b_pin_count
))
383 wake_up_all(&bp
->b_waiters
);
385 if (freed
&& stale
) {
386 ASSERT(bip
->bli_flags
& XFS_BLI_STALE
);
387 ASSERT(xfs_buf_islocked(bp
));
388 ASSERT(XFS_BUF_ISSTALE(bp
));
389 ASSERT(bip
->__bli_format
.blf_flags
& XFS_BLF_CANCEL
);
391 trace_xfs_buf_item_unpin_stale(bip
);
395 * If we are in a transaction context, we have to
396 * remove the log item from the transaction as we are
397 * about to release our reference to the buffer. If we
398 * don't, the unlock that occurs later in
399 * xfs_trans_uncommit() will try to reference the
400 * buffer which we no longer have a hold on.
403 xfs_trans_del_item(lip
);
406 * Since the transaction no longer refers to the buffer,
407 * the buffer should no longer refer to the transaction.
413 * If we get called here because of an IO error, we may
414 * or may not have the item on the AIL. xfs_trans_ail_delete()
415 * will take care of that situation.
416 * xfs_trans_ail_delete() drops the AIL lock.
418 if (bip
->bli_flags
& XFS_BLI_STALE_INODE
) {
419 xfs_buf_do_callbacks(bp
);
423 spin_lock(&ailp
->xa_lock
);
424 xfs_trans_ail_delete(ailp
, lip
, SHUTDOWN_LOG_IO_ERROR
);
425 xfs_buf_item_relse(bp
);
426 ASSERT(bp
->b_fspriv
== NULL
);
429 } else if (freed
&& remove
) {
431 * There are currently two references to the buffer - the active
432 * LRU reference and the buf log item. What we are about to do
433 * here - simulate a failed IO completion - requires 3
436 * The LRU reference is removed by the xfs_buf_stale() call. The
437 * buf item reference is removed by the xfs_buf_iodone()
438 * callback that is run by xfs_buf_do_callbacks() during ioend
439 * processing (via the bp->b_iodone callback), and then finally
440 * the ioend processing will drop the IO reference if the buffer
441 * is marked XBF_ASYNC.
443 * Hence we need to take an additional reference here so that IO
444 * completion processing doesn't free the buffer prematurely.
448 bp
->b_flags
|= XBF_ASYNC
;
449 xfs_buf_ioerror(bp
, EIO
);
452 xfs_buf_ioend(bp
, 0);
458 struct xfs_log_item
*lip
,
459 struct list_head
*buffer_list
)
461 struct xfs_buf_log_item
*bip
= BUF_ITEM(lip
);
462 struct xfs_buf
*bp
= bip
->bli_buf
;
463 uint rval
= XFS_ITEM_SUCCESS
;
465 if (xfs_buf_ispinned(bp
))
466 return XFS_ITEM_PINNED
;
467 if (!xfs_buf_trylock(bp
)) {
469 * If we have just raced with a buffer being pinned and it has
470 * been marked stale, we could end up stalling until someone else
471 * issues a log force to unpin the stale buffer. Check for the
472 * race condition here so xfsaild recognizes the buffer is pinned
473 * and queues a log force to move it along.
475 if (xfs_buf_ispinned(bp
))
476 return XFS_ITEM_PINNED
;
477 return XFS_ITEM_LOCKED
;
480 ASSERT(!(bip
->bli_flags
& XFS_BLI_STALE
));
482 trace_xfs_buf_item_push(bip
);
484 if (!xfs_buf_delwri_queue(bp
, buffer_list
))
485 rval
= XFS_ITEM_FLUSHING
;
491 * Release the buffer associated with the buf log item. If there is no dirty
492 * logged data associated with the buffer recorded in the buf log item, then
493 * free the buf log item and remove the reference to it in the buffer.
495 * This call ignores the recursion count. It is only called when the buffer
496 * should REALLY be unlocked, regardless of the recursion count.
498 * We unconditionally drop the transaction's reference to the log item. If the
499 * item was logged, then another reference was taken when it was pinned, so we
500 * can safely drop the transaction reference now. This also allows us to avoid
501 * potential races with the unpin code freeing the bli by not referencing the
502 * bli after we've dropped the reference count.
504 * If the XFS_BLI_HOLD flag is set in the buf log item, then free the log item
505 * if necessary but do not unlock the buffer. This is for support of
506 * xfs_trans_bhold(). Make sure the XFS_BLI_HOLD field is cleared if we don't
511 struct xfs_log_item
*lip
)
513 struct xfs_buf_log_item
*bip
= BUF_ITEM(lip
);
514 struct xfs_buf
*bp
= bip
->bli_buf
;
515 int aborted
, clean
, i
;
518 /* Clear the buffer's association with this transaction. */
522 * If this is a transaction abort, don't return early. Instead, allow
523 * the brelse to happen. Normally it would be done for stale
524 * (cancelled) buffers at unpin time, but we'll never go through the
525 * pin/unpin cycle if we abort inside commit.
527 aborted
= (lip
->li_flags
& XFS_LI_ABORTED
) != 0;
530 * Before possibly freeing the buf item, determine if we should
531 * release the buffer at the end of this routine.
533 hold
= bip
->bli_flags
& XFS_BLI_HOLD
;
535 /* Clear the per transaction state. */
536 bip
->bli_flags
&= ~(XFS_BLI_LOGGED
| XFS_BLI_HOLD
);
539 * If the buf item is marked stale, then don't do anything. We'll
540 * unlock the buffer and free the buf item when the buffer is unpinned
543 if (bip
->bli_flags
& XFS_BLI_STALE
) {
544 trace_xfs_buf_item_unlock_stale(bip
);
545 ASSERT(bip
->__bli_format
.blf_flags
& XFS_BLF_CANCEL
);
547 atomic_dec(&bip
->bli_refcount
);
552 trace_xfs_buf_item_unlock(bip
);
555 * If the buf item isn't tracking any data, free it, otherwise drop the
556 * reference we hold to it. If we are aborting the transaction, this may
557 * be the only reference to the buf item, so we free it anyway
558 * regardless of whether it is dirty or not. A dirty abort implies a
562 for (i
= 0; i
< bip
->bli_format_count
; i
++) {
563 if (!xfs_bitmap_empty(bip
->bli_formats
[i
].blf_data_map
,
564 bip
->bli_formats
[i
].blf_map_size
)) {
570 xfs_buf_item_relse(bp
);
572 if (atomic_dec_and_test(&bip
->bli_refcount
)) {
573 ASSERT(XFS_FORCED_SHUTDOWN(lip
->li_mountp
));
574 xfs_buf_item_relse(bp
);
577 atomic_dec(&bip
->bli_refcount
);
584 * This is called to find out where the oldest active copy of the
585 * buf log item in the on disk log resides now that the last log
586 * write of it completed at the given lsn.
587 * We always re-log all the dirty data in a buffer, so usually the
588 * latest copy in the on disk log is the only one that matters. For
589 * those cases we simply return the given lsn.
591 * The one exception to this is for buffers full of newly allocated
592 * inodes. These buffers are only relogged with the XFS_BLI_INODE_BUF
593 * flag set, indicating that only the di_next_unlinked fields from the
594 * inodes in the buffers will be replayed during recovery. If the
595 * original newly allocated inode images have not yet been flushed
596 * when the buffer is so relogged, then we need to make sure that we
597 * keep the old images in the 'active' portion of the log. We do this
598 * by returning the original lsn of that transaction here rather than
602 xfs_buf_item_committed(
603 struct xfs_log_item
*lip
,
606 struct xfs_buf_log_item
*bip
= BUF_ITEM(lip
);
608 trace_xfs_buf_item_committed(bip
);
610 if ((bip
->bli_flags
& XFS_BLI_INODE_ALLOC_BUF
) && lip
->li_lsn
!= 0)
616 xfs_buf_item_committing(
617 struct xfs_log_item
*lip
,
618 xfs_lsn_t commit_lsn
)
623 * This is the ops vector shared by all buf log items.
625 static const struct xfs_item_ops xfs_buf_item_ops
= {
626 .iop_size
= xfs_buf_item_size
,
627 .iop_format
= xfs_buf_item_format
,
628 .iop_pin
= xfs_buf_item_pin
,
629 .iop_unpin
= xfs_buf_item_unpin
,
630 .iop_unlock
= xfs_buf_item_unlock
,
631 .iop_committed
= xfs_buf_item_committed
,
632 .iop_push
= xfs_buf_item_push
,
633 .iop_committing
= xfs_buf_item_committing
637 xfs_buf_item_get_format(
638 struct xfs_buf_log_item
*bip
,
641 ASSERT(bip
->bli_formats
== NULL
);
642 bip
->bli_format_count
= count
;
645 bip
->bli_formats
= &bip
->__bli_format
;
649 bip
->bli_formats
= kmem_zalloc(count
* sizeof(struct xfs_buf_log_format
),
651 if (!bip
->bli_formats
)
657 xfs_buf_item_free_format(
658 struct xfs_buf_log_item
*bip
)
660 if (bip
->bli_formats
!= &bip
->__bli_format
) {
661 kmem_free(bip
->bli_formats
);
662 bip
->bli_formats
= NULL
;
667 * Allocate a new buf log item to go with the given buffer.
668 * Set the buffer's b_fsprivate field to point to the new
669 * buf log item. If there are other item's attached to the
670 * buffer (see xfs_buf_attach_iodone() below), then put the
671 * buf log item at the front.
678 xfs_log_item_t
*lip
= bp
->b_fspriv
;
679 xfs_buf_log_item_t
*bip
;
686 * Check to see if there is already a buf log item for
687 * this buffer. If there is, it is guaranteed to be
688 * the first. If we do already have one, there is
689 * nothing to do here so return.
691 ASSERT(bp
->b_target
->bt_mount
== mp
);
692 if (lip
!= NULL
&& lip
->li_type
== XFS_LI_BUF
)
695 bip
= kmem_zone_zalloc(xfs_buf_item_zone
, KM_SLEEP
);
696 xfs_log_item_init(mp
, &bip
->bli_item
, XFS_LI_BUF
, &xfs_buf_item_ops
);
701 * chunks is the number of XFS_BLF_CHUNK size pieces the buffer
702 * can be divided into. Make sure not to truncate any pieces.
703 * map_size is the size of the bitmap needed to describe the
704 * chunks of the buffer.
706 * Discontiguous buffer support follows the layout of the underlying
707 * buffer. This makes the implementation as simple as possible.
709 error
= xfs_buf_item_get_format(bip
, bp
->b_map_count
);
712 for (i
= 0; i
< bip
->bli_format_count
; i
++) {
713 chunks
= DIV_ROUND_UP(BBTOB(bp
->b_maps
[i
].bm_len
),
715 map_size
= DIV_ROUND_UP(chunks
, NBWORD
);
717 bip
->bli_formats
[i
].blf_type
= XFS_LI_BUF
;
718 bip
->bli_formats
[i
].blf_blkno
= bp
->b_maps
[i
].bm_bn
;
719 bip
->bli_formats
[i
].blf_len
= bp
->b_maps
[i
].bm_len
;
720 bip
->bli_formats
[i
].blf_map_size
= map_size
;
723 #ifdef XFS_TRANS_DEBUG
725 * Allocate the arrays for tracking what needs to be logged
726 * and what our callers request to be logged. bli_orig
727 * holds a copy of the original, clean buffer for comparison
728 * against, and bli_logged keeps a 1 bit flag per byte in
729 * the buffer to indicate which bytes the callers have asked
732 bip
->bli_orig
= kmem_alloc(BBTOB(bp
->b_length
), KM_SLEEP
);
733 memcpy(bip
->bli_orig
, bp
->b_addr
, BBTOB(bp
->b_length
));
734 bip
->bli_logged
= kmem_zalloc(BBTOB(bp
->b_length
) / NBBY
, KM_SLEEP
);
738 * Put the buf item into the list of items attached to the
739 * buffer at the front.
742 bip
->bli_item
.li_bio_list
= bp
->b_fspriv
;
748 * Mark bytes first through last inclusive as dirty in the buf
752 xfs_buf_item_log_segment(
753 struct xfs_buf_log_item
*bip
,
769 * Convert byte offsets to bit numbers.
771 first_bit
= first
>> XFS_BLF_SHIFT
;
772 last_bit
= last
>> XFS_BLF_SHIFT
;
775 * Calculate the total number of bits to be set.
777 bits_to_set
= last_bit
- first_bit
+ 1;
780 * Get a pointer to the first word in the bitmap
783 word_num
= first_bit
>> BIT_TO_WORD_SHIFT
;
784 wordp
= &map
[word_num
];
787 * Calculate the starting bit in the first word.
789 bit
= first_bit
& (uint
)(NBWORD
- 1);
792 * First set any bits in the first word of our range.
793 * If it starts at bit 0 of the word, it will be
794 * set below rather than here. That is what the variable
795 * bit tells us. The variable bits_set tracks the number
796 * of bits that have been set so far. End_bit is the number
797 * of the last bit to be set in this word plus one.
800 end_bit
= MIN(bit
+ bits_to_set
, (uint
)NBWORD
);
801 mask
= ((1 << (end_bit
- bit
)) - 1) << bit
;
804 bits_set
= end_bit
- bit
;
810 * Now set bits a whole word at a time that are between
811 * first_bit and last_bit.
813 while ((bits_to_set
- bits_set
) >= NBWORD
) {
814 *wordp
|= 0xffffffff;
820 * Finally, set any bits left to be set in one last partial word.
822 end_bit
= bits_to_set
- bits_set
;
824 mask
= (1 << end_bit
) - 1;
830 * Mark bytes first through last inclusive as dirty in the buf
835 xfs_buf_log_item_t
*bip
,
842 struct xfs_buf
*bp
= bip
->bli_buf
;
845 * Mark the item as having some dirty data for
846 * quick reference in xfs_buf_item_dirty.
848 bip
->bli_flags
|= XFS_BLI_DIRTY
;
851 * walk each buffer segment and mark them dirty appropriately.
854 for (i
= 0; i
< bip
->bli_format_count
; i
++) {
857 end
= start
+ BBTOB(bp
->b_maps
[i
].bm_len
);
859 start
+= BBTOB(bp
->b_maps
[i
].bm_len
);
867 xfs_buf_item_log_segment(bip
, first
, end
,
868 &bip
->bli_formats
[i
].blf_data_map
[0]);
870 start
+= bp
->b_maps
[i
].bm_len
;
876 * Return 1 if the buffer has some data that has been logged (at any
877 * point, not just the current transaction) and 0 if not.
881 xfs_buf_log_item_t
*bip
)
883 return (bip
->bli_flags
& XFS_BLI_DIRTY
);
888 xfs_buf_log_item_t
*bip
)
890 #ifdef XFS_TRANS_DEBUG
891 kmem_free(bip
->bli_orig
);
892 kmem_free(bip
->bli_logged
);
893 #endif /* XFS_TRANS_DEBUG */
895 xfs_buf_item_free_format(bip
);
896 kmem_zone_free(xfs_buf_item_zone
, bip
);
900 * This is called when the buf log item is no longer needed. It should
901 * free the buf log item associated with the given buffer and clear
902 * the buffer's pointer to the buf log item. If there are no more
903 * items in the list, clear the b_iodone field of the buffer (see
904 * xfs_buf_attach_iodone() below).
910 xfs_buf_log_item_t
*bip
;
912 trace_xfs_buf_item_relse(bp
, _RET_IP_
);
915 bp
->b_fspriv
= bip
->bli_item
.li_bio_list
;
916 if (bp
->b_fspriv
== NULL
)
920 xfs_buf_item_free(bip
);
925 * Add the given log item with its callback to the list of callbacks
926 * to be called when the buffer's I/O completes. If it is not set
927 * already, set the buffer's b_iodone() routine to be
928 * xfs_buf_iodone_callbacks() and link the log item into the list of
929 * items rooted at b_fsprivate. Items are always added as the second
930 * entry in the list if there is a first, because the buf item code
931 * assumes that the buf log item is first.
934 xfs_buf_attach_iodone(
936 void (*cb
)(xfs_buf_t
*, xfs_log_item_t
*),
939 xfs_log_item_t
*head_lip
;
941 ASSERT(xfs_buf_islocked(bp
));
944 head_lip
= bp
->b_fspriv
;
946 lip
->li_bio_list
= head_lip
->li_bio_list
;
947 head_lip
->li_bio_list
= lip
;
952 ASSERT(bp
->b_iodone
== NULL
||
953 bp
->b_iodone
== xfs_buf_iodone_callbacks
);
954 bp
->b_iodone
= xfs_buf_iodone_callbacks
;
958 * We can have many callbacks on a buffer. Running the callbacks individually
959 * can cause a lot of contention on the AIL lock, so we allow for a single
960 * callback to be able to scan the remaining lip->li_bio_list for other items
961 * of the same type and callback to be processed in the first call.
963 * As a result, the loop walking the callback list below will also modify the
964 * list. it removes the first item from the list and then runs the callback.
965 * The loop then restarts from the new head of the list. This allows the
966 * callback to scan and modify the list attached to the buffer and we don't
967 * have to care about maintaining a next item pointer.
970 xfs_buf_do_callbacks(
973 struct xfs_log_item
*lip
;
975 while ((lip
= bp
->b_fspriv
) != NULL
) {
976 bp
->b_fspriv
= lip
->li_bio_list
;
977 ASSERT(lip
->li_cb
!= NULL
);
979 * Clear the next pointer so we don't have any
980 * confusion if the item is added to another buf.
981 * Don't touch the log item after calling its
982 * callback, because it could have freed itself.
984 lip
->li_bio_list
= NULL
;
990 * This is the iodone() function for buffers which have had callbacks
991 * attached to them by xfs_buf_attach_iodone(). It should remove each
992 * log item from the buffer's list and call the callback of each in turn.
993 * When done, the buffer's fsprivate field is set to NULL and the buffer
994 * is unlocked with a call to iodone().
997 xfs_buf_iodone_callbacks(
1000 struct xfs_log_item
*lip
= bp
->b_fspriv
;
1001 struct xfs_mount
*mp
= lip
->li_mountp
;
1002 static ulong lasttime
;
1003 static xfs_buftarg_t
*lasttarg
;
1005 if (likely(!xfs_buf_geterror(bp
)))
1009 * If we've already decided to shutdown the filesystem because of
1010 * I/O errors, there's no point in giving this a retry.
1012 if (XFS_FORCED_SHUTDOWN(mp
)) {
1015 trace_xfs_buf_item_iodone(bp
, _RET_IP_
);
1019 if (bp
->b_target
!= lasttarg
||
1020 time_after(jiffies
, (lasttime
+ 5*HZ
))) {
1022 xfs_buf_ioerror_alert(bp
, __func__
);
1024 lasttarg
= bp
->b_target
;
1027 * If the write was asynchronous then no one will be looking for the
1028 * error. Clear the error state and write the buffer out again.
1030 * XXX: This helps against transient write errors, but we need to find
1031 * a way to shut the filesystem down if the writes keep failing.
1033 * In practice we'll shut the filesystem down soon as non-transient
1034 * erorrs tend to affect the whole device and a failing log write
1035 * will make us give up. But we really ought to do better here.
1037 if (XFS_BUF_ISASYNC(bp
)) {
1038 ASSERT(bp
->b_iodone
!= NULL
);
1040 trace_xfs_buf_item_iodone_async(bp
, _RET_IP_
);
1042 xfs_buf_ioerror(bp
, 0); /* errno of 0 unsets the flag */
1044 if (!XFS_BUF_ISSTALE(bp
)) {
1045 bp
->b_flags
|= XBF_WRITE
| XBF_ASYNC
| XBF_DONE
;
1046 xfs_buf_iorequest(bp
);
1055 * If the write of the buffer was synchronous, we want to make
1056 * sure to return the error to the caller of xfs_bwrite().
1061 trace_xfs_buf_error_relse(bp
, _RET_IP_
);
1064 xfs_buf_do_callbacks(bp
);
1065 bp
->b_fspriv
= NULL
;
1066 bp
->b_iodone
= NULL
;
1067 xfs_buf_ioend(bp
, 0);
1071 * This is the iodone() function for buffers which have been
1072 * logged. It is called when they are eventually flushed out.
1073 * It should remove the buf item from the AIL, and free the buf item.
1074 * It is called by xfs_buf_iodone_callbacks() above which will take
1075 * care of cleaning up the buffer itself.
1080 struct xfs_log_item
*lip
)
1082 struct xfs_ail
*ailp
= lip
->li_ailp
;
1084 ASSERT(BUF_ITEM(lip
)->bli_buf
== bp
);
1089 * If we are forcibly shutting down, this may well be
1090 * off the AIL already. That's because we simulate the
1091 * log-committed callbacks to unpin these buffers. Or we may never
1092 * have put this item on AIL because of the transaction was
1093 * aborted forcibly. xfs_trans_ail_delete() takes care of these.
1095 * Either way, AIL is useless if we're forcing a shutdown.
1097 spin_lock(&ailp
->xa_lock
);
1098 xfs_trans_ail_delete(ailp
, lip
, SHUTDOWN_CORRUPT_INCORE
);
1099 xfs_buf_item_free(BUF_ITEM(lip
));