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1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
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.
8 *
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.
13 *
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
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_format.h"
21#include "xfs_log_format.h"
22#include "xfs_trans_resv.h"
23#include "xfs_bit.h"
24#include "xfs_sb.h"
25#include "xfs_mount.h"
26#include "xfs_trans.h"
27#include "xfs_buf_item.h"
28#include "xfs_trans_priv.h"
29#include "xfs_error.h"
30#include "xfs_trace.h"
31#include "xfs_log.h"
32
33
34kmem_zone_t *xfs_buf_item_zone;
35
36static inline struct xfs_buf_log_item *BUF_ITEM(struct xfs_log_item *lip)
37{
38 return container_of(lip, struct xfs_buf_log_item, bli_item);
39}
40
41STATIC void xfs_buf_do_callbacks(struct xfs_buf *bp);
42
43static inline int
44xfs_buf_log_format_size(
45 struct xfs_buf_log_format *blfp)
46{
47 return offsetof(struct xfs_buf_log_format, blf_data_map) +
48 (blfp->blf_map_size * sizeof(blfp->blf_data_map[0]));
49}
50
51/*
52 * This returns the number of log iovecs needed to log the
53 * given buf log item.
54 *
55 * It calculates this as 1 iovec for the buf log format structure
56 * and 1 for each stretch of non-contiguous chunks to be logged.
57 * Contiguous chunks are logged in a single iovec.
58 *
59 * If the XFS_BLI_STALE flag has been set, then log nothing.
60 */
61STATIC void
62xfs_buf_item_size_segment(
63 struct xfs_buf_log_item *bip,
64 struct xfs_buf_log_format *blfp,
65 int *nvecs,
66 int *nbytes)
67{
68 struct xfs_buf *bp = bip->bli_buf;
69 int next_bit;
70 int last_bit;
71
72 last_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0);
73 if (last_bit == -1)
74 return;
75
76 /*
77 * initial count for a dirty buffer is 2 vectors - the format structure
78 * and the first dirty region.
79 */
80 *nvecs += 2;
81 *nbytes += xfs_buf_log_format_size(blfp) + XFS_BLF_CHUNK;
82
83 while (last_bit != -1) {
84 /*
85 * This takes the bit number to start looking from and
86 * returns the next set bit from there. It returns -1
87 * if there are no more bits set or the start bit is
88 * beyond the end of the bitmap.
89 */
90 next_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
91 last_bit + 1);
92 /*
93 * If we run out of bits, leave the loop,
94 * else if we find a new set of bits bump the number of vecs,
95 * else keep scanning the current set of bits.
96 */
97 if (next_bit == -1) {
98 break;
99 } else if (next_bit != last_bit + 1) {
100 last_bit = next_bit;
101 (*nvecs)++;
102 } else if (xfs_buf_offset(bp, next_bit * XFS_BLF_CHUNK) !=
103 (xfs_buf_offset(bp, last_bit * XFS_BLF_CHUNK) +
104 XFS_BLF_CHUNK)) {
105 last_bit = next_bit;
106 (*nvecs)++;
107 } else {
108 last_bit++;
109 }
110 *nbytes += XFS_BLF_CHUNK;
111 }
112}
113
114/*
115 * This returns the number of log iovecs needed to log the given buf log item.
116 *
117 * It calculates this as 1 iovec for the buf log format structure and 1 for each
118 * stretch of non-contiguous chunks to be logged. Contiguous chunks are logged
119 * in a single iovec.
120 *
121 * Discontiguous buffers need a format structure per region that that is being
122 * logged. This makes the changes in the buffer appear to log recovery as though
123 * they came from separate buffers, just like would occur if multiple buffers
124 * were used instead of a single discontiguous buffer. This enables
125 * discontiguous buffers to be in-memory constructs, completely transparent to
126 * what ends up on disk.
127 *
128 * If the XFS_BLI_STALE flag has been set, then log nothing but the buf log
129 * format structures.
130 */
131STATIC void
132xfs_buf_item_size(
133 struct xfs_log_item *lip,
134 int *nvecs,
135 int *nbytes)
136{
137 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
138 int i;
139
140 ASSERT(atomic_read(&bip->bli_refcount) > 0);
141 if (bip->bli_flags & XFS_BLI_STALE) {
142 /*
143 * The buffer is stale, so all we need to log
144 * is the buf log format structure with the
145 * cancel flag in it.
146 */
147 trace_xfs_buf_item_size_stale(bip);
148 ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
149 *nvecs += bip->bli_format_count;
150 for (i = 0; i < bip->bli_format_count; i++) {
151 *nbytes += xfs_buf_log_format_size(&bip->bli_formats[i]);
152 }
153 return;
154 }
155
156 ASSERT(bip->bli_flags & XFS_BLI_LOGGED);
157
158 if (bip->bli_flags & XFS_BLI_ORDERED) {
159 /*
160 * The buffer has been logged just to order it.
161 * It is not being included in the transaction
162 * commit, so no vectors are used at all.
163 */
164 trace_xfs_buf_item_size_ordered(bip);
165 *nvecs = XFS_LOG_VEC_ORDERED;
166 return;
167 }
168
169 /*
170 * the vector count is based on the number of buffer vectors we have
171 * dirty bits in. This will only be greater than one when we have a
172 * compound buffer with more than one segment dirty. Hence for compound
173 * buffers we need to track which segment the dirty bits correspond to,
174 * and when we move from one segment to the next increment the vector
175 * count for the extra buf log format structure that will need to be
176 * written.
177 */
178 for (i = 0; i < bip->bli_format_count; i++) {
179 xfs_buf_item_size_segment(bip, &bip->bli_formats[i],
180 nvecs, nbytes);
181 }
182 trace_xfs_buf_item_size(bip);
183}
184
185static inline void
186xfs_buf_item_copy_iovec(
187 struct xfs_log_vec *lv,
188 struct xfs_log_iovec **vecp,
189 struct xfs_buf *bp,
190 uint offset,
191 int first_bit,
192 uint nbits)
193{
194 offset += first_bit * XFS_BLF_CHUNK;
195 xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_BCHUNK,
196 xfs_buf_offset(bp, offset),
197 nbits * XFS_BLF_CHUNK);
198}
199
200static inline bool
201xfs_buf_item_straddle(
202 struct xfs_buf *bp,
203 uint offset,
204 int next_bit,
205 int last_bit)
206{
207 return xfs_buf_offset(bp, offset + (next_bit << XFS_BLF_SHIFT)) !=
208 (xfs_buf_offset(bp, offset + (last_bit << XFS_BLF_SHIFT)) +
209 XFS_BLF_CHUNK);
210}
211
212static void
213xfs_buf_item_format_segment(
214 struct xfs_buf_log_item *bip,
215 struct xfs_log_vec *lv,
216 struct xfs_log_iovec **vecp,
217 uint offset,
218 struct xfs_buf_log_format *blfp)
219{
220 struct xfs_buf *bp = bip->bli_buf;
221 uint base_size;
222 int first_bit;
223 int last_bit;
224 int next_bit;
225 uint nbits;
226
227 /* copy the flags across from the base format item */
228 blfp->blf_flags = bip->__bli_format.blf_flags;
229
230 /*
231 * Base size is the actual size of the ondisk structure - it reflects
232 * the actual size of the dirty bitmap rather than the size of the in
233 * memory structure.
234 */
235 base_size = xfs_buf_log_format_size(blfp);
236
237 first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0);
238 if (!(bip->bli_flags & XFS_BLI_STALE) && first_bit == -1) {
239 /*
240 * If the map is not be dirty in the transaction, mark
241 * the size as zero and do not advance the vector pointer.
242 */
243 return;
244 }
245
246 blfp = xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_BFORMAT, blfp, base_size);
247 blfp->blf_size = 1;
248
249 if (bip->bli_flags & XFS_BLI_STALE) {
250 /*
251 * The buffer is stale, so all we need to log
252 * is the buf log format structure with the
253 * cancel flag in it.
254 */
255 trace_xfs_buf_item_format_stale(bip);
256 ASSERT(blfp->blf_flags & XFS_BLF_CANCEL);
257 return;
258 }
259
260
261 /*
262 * Fill in an iovec for each set of contiguous chunks.
263 */
264 last_bit = first_bit;
265 nbits = 1;
266 for (;;) {
267 /*
268 * This takes the bit number to start looking from and
269 * returns the next set bit from there. It returns -1
270 * if there are no more bits set or the start bit is
271 * beyond the end of the bitmap.
272 */
273 next_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
274 (uint)last_bit + 1);
275 /*
276 * If we run out of bits fill in the last iovec and get out of
277 * the loop. Else if we start a new set of bits then fill in
278 * the iovec for the series we were looking at and start
279 * counting the bits in the new one. Else we're still in the
280 * same set of bits so just keep counting and scanning.
281 */
282 if (next_bit == -1) {
283 xfs_buf_item_copy_iovec(lv, vecp, bp, offset,
284 first_bit, nbits);
285 blfp->blf_size++;
286 break;
287 } else if (next_bit != last_bit + 1 ||
288 xfs_buf_item_straddle(bp, offset, next_bit, last_bit)) {
289 xfs_buf_item_copy_iovec(lv, vecp, bp, offset,
290 first_bit, nbits);
291 blfp->blf_size++;
292 first_bit = next_bit;
293 last_bit = next_bit;
294 nbits = 1;
295 } else {
296 last_bit++;
297 nbits++;
298 }
299 }
300}
301
302/*
303 * This is called to fill in the vector of log iovecs for the
304 * given log buf item. It fills the first entry with a buf log
305 * format structure, and the rest point to contiguous chunks
306 * within the buffer.
307 */
308STATIC void
309xfs_buf_item_format(
310 struct xfs_log_item *lip,
311 struct xfs_log_vec *lv)
312{
313 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
314 struct xfs_buf *bp = bip->bli_buf;
315 struct xfs_log_iovec *vecp = NULL;
316 uint offset = 0;
317 int i;
318
319 ASSERT(atomic_read(&bip->bli_refcount) > 0);
320 ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
321 (bip->bli_flags & XFS_BLI_STALE));
322 ASSERT((bip->bli_flags & XFS_BLI_STALE) ||
323 (xfs_blft_from_flags(&bip->__bli_format) > XFS_BLFT_UNKNOWN_BUF
324 && xfs_blft_from_flags(&bip->__bli_format) < XFS_BLFT_MAX_BUF));
325
326
327 /*
328 * If it is an inode buffer, transfer the in-memory state to the
329 * format flags and clear the in-memory state.
330 *
331 * For buffer based inode allocation, we do not transfer
332 * this state if the inode buffer allocation has not yet been committed
333 * to the log as setting the XFS_BLI_INODE_BUF flag will prevent
334 * correct replay of the inode allocation.
335 *
336 * For icreate item based inode allocation, the buffers aren't written
337 * to the journal during allocation, and hence we should always tag the
338 * buffer as an inode buffer so that the correct unlinked list replay
339 * occurs during recovery.
340 */
341 if (bip->bli_flags & XFS_BLI_INODE_BUF) {
342 if (xfs_sb_version_hascrc(&lip->li_mountp->m_sb) ||
343 !((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) &&
344 xfs_log_item_in_current_chkpt(lip)))
345 bip->__bli_format.blf_flags |= XFS_BLF_INODE_BUF;
346 bip->bli_flags &= ~XFS_BLI_INODE_BUF;
347 }
348
349 if ((bip->bli_flags & (XFS_BLI_ORDERED|XFS_BLI_STALE)) ==
350 XFS_BLI_ORDERED) {
351 /*
352 * The buffer has been logged just to order it. It is not being
353 * included in the transaction commit, so don't format it.
354 */
355 trace_xfs_buf_item_format_ordered(bip);
356 return;
357 }
358
359 for (i = 0; i < bip->bli_format_count; i++) {
360 xfs_buf_item_format_segment(bip, lv, &vecp, offset,
361 &bip->bli_formats[i]);
362 offset += bp->b_maps[i].bm_len;
363 }
364
365 /*
366 * Check to make sure everything is consistent.
367 */
368 trace_xfs_buf_item_format(bip);
369}
370
371/*
372 * This is called to pin the buffer associated with the buf log item in memory
373 * so it cannot be written out.
374 *
375 * We also always take a reference to the buffer log item here so that the bli
376 * is held while the item is pinned in memory. This means that we can
377 * unconditionally drop the reference count a transaction holds when the
378 * transaction is completed.
379 */
380STATIC void
381xfs_buf_item_pin(
382 struct xfs_log_item *lip)
383{
384 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
385
386 ASSERT(atomic_read(&bip->bli_refcount) > 0);
387 ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
388 (bip->bli_flags & XFS_BLI_ORDERED) ||
389 (bip->bli_flags & XFS_BLI_STALE));
390
391 trace_xfs_buf_item_pin(bip);
392
393 atomic_inc(&bip->bli_refcount);
394 atomic_inc(&bip->bli_buf->b_pin_count);
395}
396
397/*
398 * This is called to unpin the buffer associated with the buf log
399 * item which was previously pinned with a call to xfs_buf_item_pin().
400 *
401 * Also drop the reference to the buf item for the current transaction.
402 * If the XFS_BLI_STALE flag is set and we are the last reference,
403 * then free up the buf log item and unlock the buffer.
404 *
405 * If the remove flag is set we are called from uncommit in the
406 * forced-shutdown path. If that is true and the reference count on
407 * the log item is going to drop to zero we need to free the item's
408 * descriptor in the transaction.
409 */
410STATIC void
411xfs_buf_item_unpin(
412 struct xfs_log_item *lip,
413 int remove)
414{
415 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
416 xfs_buf_t *bp = bip->bli_buf;
417 struct xfs_ail *ailp = lip->li_ailp;
418 int stale = bip->bli_flags & XFS_BLI_STALE;
419 int freed;
420
421 ASSERT(bp->b_fspriv == bip);
422 ASSERT(atomic_read(&bip->bli_refcount) > 0);
423
424 trace_xfs_buf_item_unpin(bip);
425
426 freed = atomic_dec_and_test(&bip->bli_refcount);
427
428 if (atomic_dec_and_test(&bp->b_pin_count))
429 wake_up_all(&bp->b_waiters);
430
431 if (freed && stale) {
432 ASSERT(bip->bli_flags & XFS_BLI_STALE);
433 ASSERT(xfs_buf_islocked(bp));
434 ASSERT(bp->b_flags & XBF_STALE);
435 ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
436
437 trace_xfs_buf_item_unpin_stale(bip);
438
439 if (remove) {
440 /*
441 * If we are in a transaction context, we have to
442 * remove the log item from the transaction as we are
443 * about to release our reference to the buffer. If we
444 * don't, the unlock that occurs later in
445 * xfs_trans_uncommit() will try to reference the
446 * buffer which we no longer have a hold on.
447 */
448 if (lip->li_desc)
449 xfs_trans_del_item(lip);
450
451 /*
452 * Since the transaction no longer refers to the buffer,
453 * the buffer should no longer refer to the transaction.
454 */
455 bp->b_transp = NULL;
456 }
457
458 /*
459 * If we get called here because of an IO error, we may
460 * or may not have the item on the AIL. xfs_trans_ail_delete()
461 * will take care of that situation.
462 * xfs_trans_ail_delete() drops the AIL lock.
463 */
464 if (bip->bli_flags & XFS_BLI_STALE_INODE) {
465 xfs_buf_do_callbacks(bp);
466 bp->b_fspriv = NULL;
467 bp->b_iodone = NULL;
468 } else {
469 spin_lock(&ailp->xa_lock);
470 xfs_trans_ail_delete(ailp, lip, SHUTDOWN_LOG_IO_ERROR);
471 xfs_buf_item_relse(bp);
472 ASSERT(bp->b_fspriv == NULL);
473 }
474 xfs_buf_relse(bp);
475 } else if (freed && remove) {
476 /*
477 * There are currently two references to the buffer - the active
478 * LRU reference and the buf log item. What we are about to do
479 * here - simulate a failed IO completion - requires 3
480 * references.
481 *
482 * The LRU reference is removed by the xfs_buf_stale() call. The
483 * buf item reference is removed by the xfs_buf_iodone()
484 * callback that is run by xfs_buf_do_callbacks() during ioend
485 * processing (via the bp->b_iodone callback), and then finally
486 * the ioend processing will drop the IO reference if the buffer
487 * is marked XBF_ASYNC.
488 *
489 * Hence we need to take an additional reference here so that IO
490 * completion processing doesn't free the buffer prematurely.
491 */
492 xfs_buf_lock(bp);
493 xfs_buf_hold(bp);
494 bp->b_flags |= XBF_ASYNC;
495 xfs_buf_ioerror(bp, -EIO);
496 bp->b_flags &= ~XBF_DONE;
497 xfs_buf_stale(bp);
498 xfs_buf_ioend(bp);
499 }
500}
501
502/*
503 * Buffer IO error rate limiting. Limit it to no more than 10 messages per 30
504 * seconds so as to not spam logs too much on repeated detection of the same
505 * buffer being bad..
506 */
507
508static DEFINE_RATELIMIT_STATE(xfs_buf_write_fail_rl_state, 30 * HZ, 10);
509
510STATIC uint
511xfs_buf_item_push(
512 struct xfs_log_item *lip,
513 struct list_head *buffer_list)
514{
515 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
516 struct xfs_buf *bp = bip->bli_buf;
517 uint rval = XFS_ITEM_SUCCESS;
518
519 if (xfs_buf_ispinned(bp))
520 return XFS_ITEM_PINNED;
521 if (!xfs_buf_trylock(bp)) {
522 /*
523 * If we have just raced with a buffer being pinned and it has
524 * been marked stale, we could end up stalling until someone else
525 * issues a log force to unpin the stale buffer. Check for the
526 * race condition here so xfsaild recognizes the buffer is pinned
527 * and queues a log force to move it along.
528 */
529 if (xfs_buf_ispinned(bp))
530 return XFS_ITEM_PINNED;
531 return XFS_ITEM_LOCKED;
532 }
533
534 ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
535
536 trace_xfs_buf_item_push(bip);
537
538 /* has a previous flush failed due to IO errors? */
539 if ((bp->b_flags & XBF_WRITE_FAIL) &&
540 ___ratelimit(&xfs_buf_write_fail_rl_state, "XFS: Failing async write")) {
541 xfs_warn(bp->b_target->bt_mount,
542"Failing async write on buffer block 0x%llx. Retrying async write.",
543 (long long)bp->b_bn);
544 }
545
546 if (!xfs_buf_delwri_queue(bp, buffer_list))
547 rval = XFS_ITEM_FLUSHING;
548 xfs_buf_unlock(bp);
549 return rval;
550}
551
552/*
553 * Release the buffer associated with the buf log item. If there is no dirty
554 * logged data associated with the buffer recorded in the buf log item, then
555 * free the buf log item and remove the reference to it in the buffer.
556 *
557 * This call ignores the recursion count. It is only called when the buffer
558 * should REALLY be unlocked, regardless of the recursion count.
559 *
560 * We unconditionally drop the transaction's reference to the log item. If the
561 * item was logged, then another reference was taken when it was pinned, so we
562 * can safely drop the transaction reference now. This also allows us to avoid
563 * potential races with the unpin code freeing the bli by not referencing the
564 * bli after we've dropped the reference count.
565 *
566 * If the XFS_BLI_HOLD flag is set in the buf log item, then free the log item
567 * if necessary but do not unlock the buffer. This is for support of
568 * xfs_trans_bhold(). Make sure the XFS_BLI_HOLD field is cleared if we don't
569 * free the item.
570 */
571STATIC void
572xfs_buf_item_unlock(
573 struct xfs_log_item *lip)
574{
575 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
576 struct xfs_buf *bp = bip->bli_buf;
577 bool clean;
578 bool aborted;
579 int flags;
580
581 /* Clear the buffer's association with this transaction. */
582 bp->b_transp = NULL;
583
584 /*
585 * If this is a transaction abort, don't return early. Instead, allow
586 * the brelse to happen. Normally it would be done for stale
587 * (cancelled) buffers at unpin time, but we'll never go through the
588 * pin/unpin cycle if we abort inside commit.
589 */
590 aborted = (lip->li_flags & XFS_LI_ABORTED) ? true : false;
591 /*
592 * Before possibly freeing the buf item, copy the per-transaction state
593 * so we can reference it safely later after clearing it from the
594 * buffer log item.
595 */
596 flags = bip->bli_flags;
597 bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD | XFS_BLI_ORDERED);
598
599 /*
600 * If the buf item is marked stale, then don't do anything. We'll
601 * unlock the buffer and free the buf item when the buffer is unpinned
602 * for the last time.
603 */
604 if (flags & XFS_BLI_STALE) {
605 trace_xfs_buf_item_unlock_stale(bip);
606 ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
607 if (!aborted) {
608 atomic_dec(&bip->bli_refcount);
609 return;
610 }
611 }
612
613 trace_xfs_buf_item_unlock(bip);
614
615 /*
616 * If the buf item isn't tracking any data, free it, otherwise drop the
617 * reference we hold to it. If we are aborting the transaction, this may
618 * be the only reference to the buf item, so we free it anyway
619 * regardless of whether it is dirty or not. A dirty abort implies a
620 * shutdown, anyway.
621 *
622 * Ordered buffers are dirty but may have no recorded changes, so ensure
623 * we only release clean items here.
624 */
625 clean = (flags & XFS_BLI_DIRTY) ? false : true;
626 if (clean) {
627 int i;
628 for (i = 0; i < bip->bli_format_count; i++) {
629 if (!xfs_bitmap_empty(bip->bli_formats[i].blf_data_map,
630 bip->bli_formats[i].blf_map_size)) {
631 clean = false;
632 break;
633 }
634 }
635 }
636
637 /*
638 * Clean buffers, by definition, cannot be in the AIL. However, aborted
639 * buffers may be dirty and hence in the AIL. Therefore if we are
640 * aborting a buffer and we've just taken the last refernce away, we
641 * have to check if it is in the AIL before freeing it. We need to free
642 * it in this case, because an aborted transaction has already shut the
643 * filesystem down and this is the last chance we will have to do so.
644 */
645 if (atomic_dec_and_test(&bip->bli_refcount)) {
646 if (clean)
647 xfs_buf_item_relse(bp);
648 else if (aborted) {
649 ASSERT(XFS_FORCED_SHUTDOWN(lip->li_mountp));
650 xfs_trans_ail_remove(lip, SHUTDOWN_LOG_IO_ERROR);
651 xfs_buf_item_relse(bp);
652 }
653 }
654
655 if (!(flags & XFS_BLI_HOLD))
656 xfs_buf_relse(bp);
657}
658
659/*
660 * This is called to find out where the oldest active copy of the
661 * buf log item in the on disk log resides now that the last log
662 * write of it completed at the given lsn.
663 * We always re-log all the dirty data in a buffer, so usually the
664 * latest copy in the on disk log is the only one that matters. For
665 * those cases we simply return the given lsn.
666 *
667 * The one exception to this is for buffers full of newly allocated
668 * inodes. These buffers are only relogged with the XFS_BLI_INODE_BUF
669 * flag set, indicating that only the di_next_unlinked fields from the
670 * inodes in the buffers will be replayed during recovery. If the
671 * original newly allocated inode images have not yet been flushed
672 * when the buffer is so relogged, then we need to make sure that we
673 * keep the old images in the 'active' portion of the log. We do this
674 * by returning the original lsn of that transaction here rather than
675 * the current one.
676 */
677STATIC xfs_lsn_t
678xfs_buf_item_committed(
679 struct xfs_log_item *lip,
680 xfs_lsn_t lsn)
681{
682 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
683
684 trace_xfs_buf_item_committed(bip);
685
686 if ((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && lip->li_lsn != 0)
687 return lip->li_lsn;
688 return lsn;
689}
690
691STATIC void
692xfs_buf_item_committing(
693 struct xfs_log_item *lip,
694 xfs_lsn_t commit_lsn)
695{
696}
697
698/*
699 * This is the ops vector shared by all buf log items.
700 */
701static const struct xfs_item_ops xfs_buf_item_ops = {
702 .iop_size = xfs_buf_item_size,
703 .iop_format = xfs_buf_item_format,
704 .iop_pin = xfs_buf_item_pin,
705 .iop_unpin = xfs_buf_item_unpin,
706 .iop_unlock = xfs_buf_item_unlock,
707 .iop_committed = xfs_buf_item_committed,
708 .iop_push = xfs_buf_item_push,
709 .iop_committing = xfs_buf_item_committing
710};
711
712STATIC int
713xfs_buf_item_get_format(
714 struct xfs_buf_log_item *bip,
715 int count)
716{
717 ASSERT(bip->bli_formats == NULL);
718 bip->bli_format_count = count;
719
720 if (count == 1) {
721 bip->bli_formats = &bip->__bli_format;
722 return 0;
723 }
724
725 bip->bli_formats = kmem_zalloc(count * sizeof(struct xfs_buf_log_format),
726 KM_SLEEP);
727 if (!bip->bli_formats)
728 return -ENOMEM;
729 return 0;
730}
731
732STATIC void
733xfs_buf_item_free_format(
734 struct xfs_buf_log_item *bip)
735{
736 if (bip->bli_formats != &bip->__bli_format) {
737 kmem_free(bip->bli_formats);
738 bip->bli_formats = NULL;
739 }
740}
741
742/*
743 * Allocate a new buf log item to go with the given buffer.
744 * Set the buffer's b_fsprivate field to point to the new
745 * buf log item. If there are other item's attached to the
746 * buffer (see xfs_buf_attach_iodone() below), then put the
747 * buf log item at the front.
748 */
749int
750xfs_buf_item_init(
751 struct xfs_buf *bp,
752 struct xfs_mount *mp)
753{
754 struct xfs_log_item *lip = bp->b_fspriv;
755 struct xfs_buf_log_item *bip;
756 int chunks;
757 int map_size;
758 int error;
759 int i;
760
761 /*
762 * Check to see if there is already a buf log item for
763 * this buffer. If there is, it is guaranteed to be
764 * the first. If we do already have one, there is
765 * nothing to do here so return.
766 */
767 ASSERT(bp->b_target->bt_mount == mp);
768 if (lip != NULL && lip->li_type == XFS_LI_BUF)
769 return 0;
770
771 bip = kmem_zone_zalloc(xfs_buf_item_zone, KM_SLEEP);
772 xfs_log_item_init(mp, &bip->bli_item, XFS_LI_BUF, &xfs_buf_item_ops);
773 bip->bli_buf = bp;
774
775 /*
776 * chunks is the number of XFS_BLF_CHUNK size pieces the buffer
777 * can be divided into. Make sure not to truncate any pieces.
778 * map_size is the size of the bitmap needed to describe the
779 * chunks of the buffer.
780 *
781 * Discontiguous buffer support follows the layout of the underlying
782 * buffer. This makes the implementation as simple as possible.
783 */
784 error = xfs_buf_item_get_format(bip, bp->b_map_count);
785 ASSERT(error == 0);
786 if (error) { /* to stop gcc throwing set-but-unused warnings */
787 kmem_zone_free(xfs_buf_item_zone, bip);
788 return error;
789 }
790
791
792 for (i = 0; i < bip->bli_format_count; i++) {
793 chunks = DIV_ROUND_UP(BBTOB(bp->b_maps[i].bm_len),
794 XFS_BLF_CHUNK);
795 map_size = DIV_ROUND_UP(chunks, NBWORD);
796
797 bip->bli_formats[i].blf_type = XFS_LI_BUF;
798 bip->bli_formats[i].blf_blkno = bp->b_maps[i].bm_bn;
799 bip->bli_formats[i].blf_len = bp->b_maps[i].bm_len;
800 bip->bli_formats[i].blf_map_size = map_size;
801 }
802
803 /*
804 * Put the buf item into the list of items attached to the
805 * buffer at the front.
806 */
807 if (bp->b_fspriv)
808 bip->bli_item.li_bio_list = bp->b_fspriv;
809 bp->b_fspriv = bip;
810 xfs_buf_hold(bp);
811 return 0;
812}
813
814
815/*
816 * Mark bytes first through last inclusive as dirty in the buf
817 * item's bitmap.
818 */
819static void
820xfs_buf_item_log_segment(
821 uint first,
822 uint last,
823 uint *map)
824{
825 uint first_bit;
826 uint last_bit;
827 uint bits_to_set;
828 uint bits_set;
829 uint word_num;
830 uint *wordp;
831 uint bit;
832 uint end_bit;
833 uint mask;
834
835 /*
836 * Convert byte offsets to bit numbers.
837 */
838 first_bit = first >> XFS_BLF_SHIFT;
839 last_bit = last >> XFS_BLF_SHIFT;
840
841 /*
842 * Calculate the total number of bits to be set.
843 */
844 bits_to_set = last_bit - first_bit + 1;
845
846 /*
847 * Get a pointer to the first word in the bitmap
848 * to set a bit in.
849 */
850 word_num = first_bit >> BIT_TO_WORD_SHIFT;
851 wordp = &map[word_num];
852
853 /*
854 * Calculate the starting bit in the first word.
855 */
856 bit = first_bit & (uint)(NBWORD - 1);
857
858 /*
859 * First set any bits in the first word of our range.
860 * If it starts at bit 0 of the word, it will be
861 * set below rather than here. That is what the variable
862 * bit tells us. The variable bits_set tracks the number
863 * of bits that have been set so far. End_bit is the number
864 * of the last bit to be set in this word plus one.
865 */
866 if (bit) {
867 end_bit = MIN(bit + bits_to_set, (uint)NBWORD);
868 mask = ((1 << (end_bit - bit)) - 1) << bit;
869 *wordp |= mask;
870 wordp++;
871 bits_set = end_bit - bit;
872 } else {
873 bits_set = 0;
874 }
875
876 /*
877 * Now set bits a whole word at a time that are between
878 * first_bit and last_bit.
879 */
880 while ((bits_to_set - bits_set) >= NBWORD) {
881 *wordp |= 0xffffffff;
882 bits_set += NBWORD;
883 wordp++;
884 }
885
886 /*
887 * Finally, set any bits left to be set in one last partial word.
888 */
889 end_bit = bits_to_set - bits_set;
890 if (end_bit) {
891 mask = (1 << end_bit) - 1;
892 *wordp |= mask;
893 }
894}
895
896/*
897 * Mark bytes first through last inclusive as dirty in the buf
898 * item's bitmap.
899 */
900void
901xfs_buf_item_log(
902 xfs_buf_log_item_t *bip,
903 uint first,
904 uint last)
905{
906 int i;
907 uint start;
908 uint end;
909 struct xfs_buf *bp = bip->bli_buf;
910
911 /*
912 * walk each buffer segment and mark them dirty appropriately.
913 */
914 start = 0;
915 for (i = 0; i < bip->bli_format_count; i++) {
916 if (start > last)
917 break;
918 end = start + BBTOB(bp->b_maps[i].bm_len);
919 if (first > end) {
920 start += BBTOB(bp->b_maps[i].bm_len);
921 continue;
922 }
923 if (first < start)
924 first = start;
925 if (end > last)
926 end = last;
927
928 xfs_buf_item_log_segment(first, end,
929 &bip->bli_formats[i].blf_data_map[0]);
930
931 start += bp->b_maps[i].bm_len;
932 }
933}
934
935
936/*
937 * Return 1 if the buffer has been logged or ordered in a transaction (at any
938 * point, not just the current transaction) and 0 if not.
939 */
940uint
941xfs_buf_item_dirty(
942 xfs_buf_log_item_t *bip)
943{
944 return (bip->bli_flags & XFS_BLI_DIRTY);
945}
946
947STATIC void
948xfs_buf_item_free(
949 xfs_buf_log_item_t *bip)
950{
951 xfs_buf_item_free_format(bip);
952 kmem_zone_free(xfs_buf_item_zone, bip);
953}
954
955/*
956 * This is called when the buf log item is no longer needed. It should
957 * free the buf log item associated with the given buffer and clear
958 * the buffer's pointer to the buf log item. If there are no more
959 * items in the list, clear the b_iodone field of the buffer (see
960 * xfs_buf_attach_iodone() below).
961 */
962void
963xfs_buf_item_relse(
964 xfs_buf_t *bp)
965{
966 xfs_buf_log_item_t *bip = bp->b_fspriv;
967
968 trace_xfs_buf_item_relse(bp, _RET_IP_);
969 ASSERT(!(bip->bli_item.li_flags & XFS_LI_IN_AIL));
970
971 bp->b_fspriv = bip->bli_item.li_bio_list;
972 if (bp->b_fspriv == NULL)
973 bp->b_iodone = NULL;
974
975 xfs_buf_rele(bp);
976 xfs_buf_item_free(bip);
977}
978
979
980/*
981 * Add the given log item with its callback to the list of callbacks
982 * to be called when the buffer's I/O completes. If it is not set
983 * already, set the buffer's b_iodone() routine to be
984 * xfs_buf_iodone_callbacks() and link the log item into the list of
985 * items rooted at b_fsprivate. Items are always added as the second
986 * entry in the list if there is a first, because the buf item code
987 * assumes that the buf log item is first.
988 */
989void
990xfs_buf_attach_iodone(
991 xfs_buf_t *bp,
992 void (*cb)(xfs_buf_t *, xfs_log_item_t *),
993 xfs_log_item_t *lip)
994{
995 xfs_log_item_t *head_lip;
996
997 ASSERT(xfs_buf_islocked(bp));
998
999 lip->li_cb = cb;
1000 head_lip = bp->b_fspriv;
1001 if (head_lip) {
1002 lip->li_bio_list = head_lip->li_bio_list;
1003 head_lip->li_bio_list = lip;
1004 } else {
1005 bp->b_fspriv = lip;
1006 }
1007
1008 ASSERT(bp->b_iodone == NULL ||
1009 bp->b_iodone == xfs_buf_iodone_callbacks);
1010 bp->b_iodone = xfs_buf_iodone_callbacks;
1011}
1012
1013/*
1014 * We can have many callbacks on a buffer. Running the callbacks individually
1015 * can cause a lot of contention on the AIL lock, so we allow for a single
1016 * callback to be able to scan the remaining lip->li_bio_list for other items
1017 * of the same type and callback to be processed in the first call.
1018 *
1019 * As a result, the loop walking the callback list below will also modify the
1020 * list. it removes the first item from the list and then runs the callback.
1021 * The loop then restarts from the new head of the list. This allows the
1022 * callback to scan and modify the list attached to the buffer and we don't
1023 * have to care about maintaining a next item pointer.
1024 */
1025STATIC void
1026xfs_buf_do_callbacks(
1027 struct xfs_buf *bp)
1028{
1029 struct xfs_log_item *lip;
1030
1031 while ((lip = bp->b_fspriv) != NULL) {
1032 bp->b_fspriv = lip->li_bio_list;
1033 ASSERT(lip->li_cb != NULL);
1034 /*
1035 * Clear the next pointer so we don't have any
1036 * confusion if the item is added to another buf.
1037 * Don't touch the log item after calling its
1038 * callback, because it could have freed itself.
1039 */
1040 lip->li_bio_list = NULL;
1041 lip->li_cb(bp, lip);
1042 }
1043}
1044
1045/*
1046 * This is the iodone() function for buffers which have had callbacks
1047 * attached to them by xfs_buf_attach_iodone(). It should remove each
1048 * log item from the buffer's list and call the callback of each in turn.
1049 * When done, the buffer's fsprivate field is set to NULL and the buffer
1050 * is unlocked with a call to iodone().
1051 */
1052void
1053xfs_buf_iodone_callbacks(
1054 struct xfs_buf *bp)
1055{
1056 struct xfs_log_item *lip = bp->b_fspriv;
1057 struct xfs_mount *mp = lip->li_mountp;
1058 static ulong lasttime;
1059 static xfs_buftarg_t *lasttarg;
1060
1061 if (likely(!bp->b_error))
1062 goto do_callbacks;
1063
1064 /*
1065 * If we've already decided to shutdown the filesystem because of
1066 * I/O errors, there's no point in giving this a retry.
1067 */
1068 if (XFS_FORCED_SHUTDOWN(mp)) {
1069 xfs_buf_stale(bp);
1070 bp->b_flags |= XBF_DONE;
1071 trace_xfs_buf_item_iodone(bp, _RET_IP_);
1072 goto do_callbacks;
1073 }
1074
1075 if (bp->b_target != lasttarg ||
1076 time_after(jiffies, (lasttime + 5*HZ))) {
1077 lasttime = jiffies;
1078 xfs_buf_ioerror_alert(bp, __func__);
1079 }
1080 lasttarg = bp->b_target;
1081
1082 /*
1083 * If the write was asynchronous then no one will be looking for the
1084 * error. Clear the error state and write the buffer out again.
1085 *
1086 * XXX: This helps against transient write errors, but we need to find
1087 * a way to shut the filesystem down if the writes keep failing.
1088 *
1089 * In practice we'll shut the filesystem down soon as non-transient
1090 * errors tend to affect the whole device and a failing log write
1091 * will make us give up. But we really ought to do better here.
1092 */
1093 if (bp->b_flags & XBF_ASYNC) {
1094 ASSERT(bp->b_iodone != NULL);
1095
1096 trace_xfs_buf_item_iodone_async(bp, _RET_IP_);
1097
1098 xfs_buf_ioerror(bp, 0); /* errno of 0 unsets the flag */
1099
1100 if (!(bp->b_flags & (XBF_STALE|XBF_WRITE_FAIL))) {
1101 bp->b_flags |= XBF_WRITE | XBF_ASYNC |
1102 XBF_DONE | XBF_WRITE_FAIL;
1103 xfs_buf_submit(bp);
1104 } else {
1105 xfs_buf_relse(bp);
1106 }
1107
1108 return;
1109 }
1110
1111 /*
1112 * If the write of the buffer was synchronous, we want to make
1113 * sure to return the error to the caller of xfs_bwrite().
1114 */
1115 xfs_buf_stale(bp);
1116 bp->b_flags |= XBF_DONE;
1117
1118 trace_xfs_buf_error_relse(bp, _RET_IP_);
1119
1120do_callbacks:
1121 xfs_buf_do_callbacks(bp);
1122 bp->b_fspriv = NULL;
1123 bp->b_iodone = NULL;
1124 xfs_buf_ioend(bp);
1125}
1126
1127/*
1128 * This is the iodone() function for buffers which have been
1129 * logged. It is called when they are eventually flushed out.
1130 * It should remove the buf item from the AIL, and free the buf item.
1131 * It is called by xfs_buf_iodone_callbacks() above which will take
1132 * care of cleaning up the buffer itself.
1133 */
1134void
1135xfs_buf_iodone(
1136 struct xfs_buf *bp,
1137 struct xfs_log_item *lip)
1138{
1139 struct xfs_ail *ailp = lip->li_ailp;
1140
1141 ASSERT(BUF_ITEM(lip)->bli_buf == bp);
1142
1143 xfs_buf_rele(bp);
1144
1145 /*
1146 * If we are forcibly shutting down, this may well be
1147 * off the AIL already. That's because we simulate the
1148 * log-committed callbacks to unpin these buffers. Or we may never
1149 * have put this item on AIL because of the transaction was
1150 * aborted forcibly. xfs_trans_ail_delete() takes care of these.
1151 *
1152 * Either way, AIL is useless if we're forcing a shutdown.
1153 */
1154 spin_lock(&ailp->xa_lock);
1155 xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE);
1156 xfs_buf_item_free(BUF_ITEM(lip));
1157}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_bit.h"
13#include "xfs_mount.h"
14#include "xfs_trans.h"
15#include "xfs_trans_priv.h"
16#include "xfs_buf_item.h"
17#include "xfs_inode.h"
18#include "xfs_inode_item.h"
19#include "xfs_quota.h"
20#include "xfs_dquot_item.h"
21#include "xfs_dquot.h"
22#include "xfs_trace.h"
23#include "xfs_log.h"
24#include "xfs_log_priv.h"
25
26
27struct kmem_cache *xfs_buf_item_cache;
28
29static inline struct xfs_buf_log_item *BUF_ITEM(struct xfs_log_item *lip)
30{
31 return container_of(lip, struct xfs_buf_log_item, bli_item);
32}
33
34/* Is this log iovec plausibly large enough to contain the buffer log format? */
35bool
36xfs_buf_log_check_iovec(
37 struct xfs_log_iovec *iovec)
38{
39 struct xfs_buf_log_format *blfp = iovec->i_addr;
40 char *bmp_end;
41 char *item_end;
42
43 if (offsetof(struct xfs_buf_log_format, blf_data_map) > iovec->i_len)
44 return false;
45
46 item_end = (char *)iovec->i_addr + iovec->i_len;
47 bmp_end = (char *)&blfp->blf_data_map[blfp->blf_map_size];
48 return bmp_end <= item_end;
49}
50
51static inline int
52xfs_buf_log_format_size(
53 struct xfs_buf_log_format *blfp)
54{
55 return offsetof(struct xfs_buf_log_format, blf_data_map) +
56 (blfp->blf_map_size * sizeof(blfp->blf_data_map[0]));
57}
58
59static inline bool
60xfs_buf_item_straddle(
61 struct xfs_buf *bp,
62 uint offset,
63 int first_bit,
64 int nbits)
65{
66 void *first, *last;
67
68 first = xfs_buf_offset(bp, offset + (first_bit << XFS_BLF_SHIFT));
69 last = xfs_buf_offset(bp,
70 offset + ((first_bit + nbits) << XFS_BLF_SHIFT));
71
72 if (last - first != nbits * XFS_BLF_CHUNK)
73 return true;
74 return false;
75}
76
77/*
78 * Return the number of log iovecs and space needed to log the given buf log
79 * item segment.
80 *
81 * It calculates this as 1 iovec for the buf log format structure and 1 for each
82 * stretch of non-contiguous chunks to be logged. Contiguous chunks are logged
83 * in a single iovec.
84 */
85STATIC void
86xfs_buf_item_size_segment(
87 struct xfs_buf_log_item *bip,
88 struct xfs_buf_log_format *blfp,
89 uint offset,
90 int *nvecs,
91 int *nbytes)
92{
93 struct xfs_buf *bp = bip->bli_buf;
94 int first_bit;
95 int nbits;
96 int next_bit;
97 int last_bit;
98
99 first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0);
100 if (first_bit == -1)
101 return;
102
103 (*nvecs)++;
104 *nbytes += xfs_buf_log_format_size(blfp);
105
106 do {
107 nbits = xfs_contig_bits(blfp->blf_data_map,
108 blfp->blf_map_size, first_bit);
109 ASSERT(nbits > 0);
110
111 /*
112 * Straddling a page is rare because we don't log contiguous
113 * chunks of unmapped buffers anywhere.
114 */
115 if (nbits > 1 &&
116 xfs_buf_item_straddle(bp, offset, first_bit, nbits))
117 goto slow_scan;
118
119 (*nvecs)++;
120 *nbytes += nbits * XFS_BLF_CHUNK;
121
122 /*
123 * This takes the bit number to start looking from and
124 * returns the next set bit from there. It returns -1
125 * if there are no more bits set or the start bit is
126 * beyond the end of the bitmap.
127 */
128 first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
129 (uint)first_bit + nbits + 1);
130 } while (first_bit != -1);
131
132 return;
133
134slow_scan:
135 /* Count the first bit we jumped out of the above loop from */
136 (*nvecs)++;
137 *nbytes += XFS_BLF_CHUNK;
138 last_bit = first_bit;
139 while (last_bit != -1) {
140 /*
141 * This takes the bit number to start looking from and
142 * returns the next set bit from there. It returns -1
143 * if there are no more bits set or the start bit is
144 * beyond the end of the bitmap.
145 */
146 next_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
147 last_bit + 1);
148 /*
149 * If we run out of bits, leave the loop,
150 * else if we find a new set of bits bump the number of vecs,
151 * else keep scanning the current set of bits.
152 */
153 if (next_bit == -1) {
154 break;
155 } else if (next_bit != last_bit + 1 ||
156 xfs_buf_item_straddle(bp, offset, first_bit, nbits)) {
157 last_bit = next_bit;
158 first_bit = next_bit;
159 (*nvecs)++;
160 nbits = 1;
161 } else {
162 last_bit++;
163 nbits++;
164 }
165 *nbytes += XFS_BLF_CHUNK;
166 }
167}
168
169/*
170 * Return the number of log iovecs and space needed to log the given buf log
171 * item.
172 *
173 * Discontiguous buffers need a format structure per region that is being
174 * logged. This makes the changes in the buffer appear to log recovery as though
175 * they came from separate buffers, just like would occur if multiple buffers
176 * were used instead of a single discontiguous buffer. This enables
177 * discontiguous buffers to be in-memory constructs, completely transparent to
178 * what ends up on disk.
179 *
180 * If the XFS_BLI_STALE flag has been set, then log nothing but the buf log
181 * format structures. If the item has previously been logged and has dirty
182 * regions, we do not relog them in stale buffers. This has the effect of
183 * reducing the size of the relogged item by the amount of dirty data tracked
184 * by the log item. This can result in the committing transaction reducing the
185 * amount of space being consumed by the CIL.
186 */
187STATIC void
188xfs_buf_item_size(
189 struct xfs_log_item *lip,
190 int *nvecs,
191 int *nbytes)
192{
193 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
194 struct xfs_buf *bp = bip->bli_buf;
195 int i;
196 int bytes;
197 uint offset = 0;
198
199 ASSERT(atomic_read(&bip->bli_refcount) > 0);
200 if (bip->bli_flags & XFS_BLI_STALE) {
201 /*
202 * The buffer is stale, so all we need to log is the buf log
203 * format structure with the cancel flag in it as we are never
204 * going to replay the changes tracked in the log item.
205 */
206 trace_xfs_buf_item_size_stale(bip);
207 ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
208 *nvecs += bip->bli_format_count;
209 for (i = 0; i < bip->bli_format_count; i++) {
210 *nbytes += xfs_buf_log_format_size(&bip->bli_formats[i]);
211 }
212 return;
213 }
214
215 ASSERT(bip->bli_flags & XFS_BLI_LOGGED);
216
217 if (bip->bli_flags & XFS_BLI_ORDERED) {
218 /*
219 * The buffer has been logged just to order it. It is not being
220 * included in the transaction commit, so no vectors are used at
221 * all.
222 */
223 trace_xfs_buf_item_size_ordered(bip);
224 *nvecs = XFS_LOG_VEC_ORDERED;
225 return;
226 }
227
228 /*
229 * The vector count is based on the number of buffer vectors we have
230 * dirty bits in. This will only be greater than one when we have a
231 * compound buffer with more than one segment dirty. Hence for compound
232 * buffers we need to track which segment the dirty bits correspond to,
233 * and when we move from one segment to the next increment the vector
234 * count for the extra buf log format structure that will need to be
235 * written.
236 */
237 bytes = 0;
238 for (i = 0; i < bip->bli_format_count; i++) {
239 xfs_buf_item_size_segment(bip, &bip->bli_formats[i], offset,
240 nvecs, &bytes);
241 offset += BBTOB(bp->b_maps[i].bm_len);
242 }
243
244 /*
245 * Round up the buffer size required to minimise the number of memory
246 * allocations that need to be done as this item grows when relogged by
247 * repeated modifications.
248 */
249 *nbytes = round_up(bytes, 512);
250 trace_xfs_buf_item_size(bip);
251}
252
253static inline void
254xfs_buf_item_copy_iovec(
255 struct xfs_log_vec *lv,
256 struct xfs_log_iovec **vecp,
257 struct xfs_buf *bp,
258 uint offset,
259 int first_bit,
260 uint nbits)
261{
262 offset += first_bit * XFS_BLF_CHUNK;
263 xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_BCHUNK,
264 xfs_buf_offset(bp, offset),
265 nbits * XFS_BLF_CHUNK);
266}
267
268static void
269xfs_buf_item_format_segment(
270 struct xfs_buf_log_item *bip,
271 struct xfs_log_vec *lv,
272 struct xfs_log_iovec **vecp,
273 uint offset,
274 struct xfs_buf_log_format *blfp)
275{
276 struct xfs_buf *bp = bip->bli_buf;
277 uint base_size;
278 int first_bit;
279 int last_bit;
280 int next_bit;
281 uint nbits;
282
283 /* copy the flags across from the base format item */
284 blfp->blf_flags = bip->__bli_format.blf_flags;
285
286 /*
287 * Base size is the actual size of the ondisk structure - it reflects
288 * the actual size of the dirty bitmap rather than the size of the in
289 * memory structure.
290 */
291 base_size = xfs_buf_log_format_size(blfp);
292
293 first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0);
294 if (!(bip->bli_flags & XFS_BLI_STALE) && first_bit == -1) {
295 /*
296 * If the map is not be dirty in the transaction, mark
297 * the size as zero and do not advance the vector pointer.
298 */
299 return;
300 }
301
302 blfp = xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_BFORMAT, blfp, base_size);
303 blfp->blf_size = 1;
304
305 if (bip->bli_flags & XFS_BLI_STALE) {
306 /*
307 * The buffer is stale, so all we need to log
308 * is the buf log format structure with the
309 * cancel flag in it.
310 */
311 trace_xfs_buf_item_format_stale(bip);
312 ASSERT(blfp->blf_flags & XFS_BLF_CANCEL);
313 return;
314 }
315
316
317 /*
318 * Fill in an iovec for each set of contiguous chunks.
319 */
320 do {
321 ASSERT(first_bit >= 0);
322 nbits = xfs_contig_bits(blfp->blf_data_map,
323 blfp->blf_map_size, first_bit);
324 ASSERT(nbits > 0);
325
326 /*
327 * Straddling a page is rare because we don't log contiguous
328 * chunks of unmapped buffers anywhere.
329 */
330 if (nbits > 1 &&
331 xfs_buf_item_straddle(bp, offset, first_bit, nbits))
332 goto slow_scan;
333
334 xfs_buf_item_copy_iovec(lv, vecp, bp, offset,
335 first_bit, nbits);
336 blfp->blf_size++;
337
338 /*
339 * This takes the bit number to start looking from and
340 * returns the next set bit from there. It returns -1
341 * if there are no more bits set or the start bit is
342 * beyond the end of the bitmap.
343 */
344 first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
345 (uint)first_bit + nbits + 1);
346 } while (first_bit != -1);
347
348 return;
349
350slow_scan:
351 ASSERT(bp->b_addr == NULL);
352 last_bit = first_bit;
353 nbits = 1;
354 for (;;) {
355 /*
356 * This takes the bit number to start looking from and
357 * returns the next set bit from there. It returns -1
358 * if there are no more bits set or the start bit is
359 * beyond the end of the bitmap.
360 */
361 next_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
362 (uint)last_bit + 1);
363 /*
364 * If we run out of bits fill in the last iovec and get out of
365 * the loop. Else if we start a new set of bits then fill in
366 * the iovec for the series we were looking at and start
367 * counting the bits in the new one. Else we're still in the
368 * same set of bits so just keep counting and scanning.
369 */
370 if (next_bit == -1) {
371 xfs_buf_item_copy_iovec(lv, vecp, bp, offset,
372 first_bit, nbits);
373 blfp->blf_size++;
374 break;
375 } else if (next_bit != last_bit + 1 ||
376 xfs_buf_item_straddle(bp, offset, first_bit, nbits)) {
377 xfs_buf_item_copy_iovec(lv, vecp, bp, offset,
378 first_bit, nbits);
379 blfp->blf_size++;
380 first_bit = next_bit;
381 last_bit = next_bit;
382 nbits = 1;
383 } else {
384 last_bit++;
385 nbits++;
386 }
387 }
388}
389
390/*
391 * This is called to fill in the vector of log iovecs for the
392 * given log buf item. It fills the first entry with a buf log
393 * format structure, and the rest point to contiguous chunks
394 * within the buffer.
395 */
396STATIC void
397xfs_buf_item_format(
398 struct xfs_log_item *lip,
399 struct xfs_log_vec *lv)
400{
401 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
402 struct xfs_buf *bp = bip->bli_buf;
403 struct xfs_log_iovec *vecp = NULL;
404 uint offset = 0;
405 int i;
406
407 ASSERT(atomic_read(&bip->bli_refcount) > 0);
408 ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
409 (bip->bli_flags & XFS_BLI_STALE));
410 ASSERT((bip->bli_flags & XFS_BLI_STALE) ||
411 (xfs_blft_from_flags(&bip->__bli_format) > XFS_BLFT_UNKNOWN_BUF
412 && xfs_blft_from_flags(&bip->__bli_format) < XFS_BLFT_MAX_BUF));
413 ASSERT(!(bip->bli_flags & XFS_BLI_ORDERED) ||
414 (bip->bli_flags & XFS_BLI_STALE));
415
416
417 /*
418 * If it is an inode buffer, transfer the in-memory state to the
419 * format flags and clear the in-memory state.
420 *
421 * For buffer based inode allocation, we do not transfer
422 * this state if the inode buffer allocation has not yet been committed
423 * to the log as setting the XFS_BLI_INODE_BUF flag will prevent
424 * correct replay of the inode allocation.
425 *
426 * For icreate item based inode allocation, the buffers aren't written
427 * to the journal during allocation, and hence we should always tag the
428 * buffer as an inode buffer so that the correct unlinked list replay
429 * occurs during recovery.
430 */
431 if (bip->bli_flags & XFS_BLI_INODE_BUF) {
432 if (xfs_has_v3inodes(lip->li_log->l_mp) ||
433 !((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) &&
434 xfs_log_item_in_current_chkpt(lip)))
435 bip->__bli_format.blf_flags |= XFS_BLF_INODE_BUF;
436 bip->bli_flags &= ~XFS_BLI_INODE_BUF;
437 }
438
439 for (i = 0; i < bip->bli_format_count; i++) {
440 xfs_buf_item_format_segment(bip, lv, &vecp, offset,
441 &bip->bli_formats[i]);
442 offset += BBTOB(bp->b_maps[i].bm_len);
443 }
444
445 /*
446 * Check to make sure everything is consistent.
447 */
448 trace_xfs_buf_item_format(bip);
449}
450
451/*
452 * This is called to pin the buffer associated with the buf log item in memory
453 * so it cannot be written out.
454 *
455 * We take a reference to the buffer log item here so that the BLI life cycle
456 * extends at least until the buffer is unpinned via xfs_buf_item_unpin() and
457 * inserted into the AIL.
458 *
459 * We also need to take a reference to the buffer itself as the BLI unpin
460 * processing requires accessing the buffer after the BLI has dropped the final
461 * BLI reference. See xfs_buf_item_unpin() for an explanation.
462 * If unpins race to drop the final BLI reference and only the
463 * BLI owns a reference to the buffer, then the loser of the race can have the
464 * buffer fgreed from under it (e.g. on shutdown). Taking a buffer reference per
465 * pin count ensures the life cycle of the buffer extends for as
466 * long as we hold the buffer pin reference in xfs_buf_item_unpin().
467 */
468STATIC void
469xfs_buf_item_pin(
470 struct xfs_log_item *lip)
471{
472 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
473
474 ASSERT(atomic_read(&bip->bli_refcount) > 0);
475 ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
476 (bip->bli_flags & XFS_BLI_ORDERED) ||
477 (bip->bli_flags & XFS_BLI_STALE));
478
479 trace_xfs_buf_item_pin(bip);
480
481 xfs_buf_hold(bip->bli_buf);
482 atomic_inc(&bip->bli_refcount);
483 atomic_inc(&bip->bli_buf->b_pin_count);
484}
485
486/*
487 * This is called to unpin the buffer associated with the buf log item which was
488 * previously pinned with a call to xfs_buf_item_pin(). We enter this function
489 * with a buffer pin count, a buffer reference and a BLI reference.
490 *
491 * We must drop the BLI reference before we unpin the buffer because the AIL
492 * doesn't acquire a BLI reference whenever it accesses it. Therefore if the
493 * refcount drops to zero, the bli could still be AIL resident and the buffer
494 * submitted for I/O at any point before we return. This can result in IO
495 * completion freeing the buffer while we are still trying to access it here.
496 * This race condition can also occur in shutdown situations where we abort and
497 * unpin buffers from contexts other that journal IO completion.
498 *
499 * Hence we have to hold a buffer reference per pin count to ensure that the
500 * buffer cannot be freed until we have finished processing the unpin operation.
501 * The reference is taken in xfs_buf_item_pin(), and we must hold it until we
502 * are done processing the buffer state. In the case of an abort (remove =
503 * true) then we re-use the current pin reference as the IO reference we hand
504 * off to IO failure handling.
505 */
506STATIC void
507xfs_buf_item_unpin(
508 struct xfs_log_item *lip,
509 int remove)
510{
511 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
512 struct xfs_buf *bp = bip->bli_buf;
513 int stale = bip->bli_flags & XFS_BLI_STALE;
514 int freed;
515
516 ASSERT(bp->b_log_item == bip);
517 ASSERT(atomic_read(&bip->bli_refcount) > 0);
518
519 trace_xfs_buf_item_unpin(bip);
520
521 freed = atomic_dec_and_test(&bip->bli_refcount);
522 if (atomic_dec_and_test(&bp->b_pin_count))
523 wake_up_all(&bp->b_waiters);
524
525 /*
526 * Nothing to do but drop the buffer pin reference if the BLI is
527 * still active.
528 */
529 if (!freed) {
530 xfs_buf_rele(bp);
531 return;
532 }
533
534 if (stale) {
535 ASSERT(bip->bli_flags & XFS_BLI_STALE);
536 ASSERT(xfs_buf_islocked(bp));
537 ASSERT(bp->b_flags & XBF_STALE);
538 ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
539 ASSERT(list_empty(&lip->li_trans));
540 ASSERT(!bp->b_transp);
541
542 trace_xfs_buf_item_unpin_stale(bip);
543
544 /*
545 * The buffer has been locked and referenced since it was marked
546 * stale so we own both lock and reference exclusively here. We
547 * do not need the pin reference any more, so drop it now so
548 * that we only have one reference to drop once item completion
549 * processing is complete.
550 */
551 xfs_buf_rele(bp);
552
553 /*
554 * If we get called here because of an IO error, we may or may
555 * not have the item on the AIL. xfs_trans_ail_delete() will
556 * take care of that situation. xfs_trans_ail_delete() drops
557 * the AIL lock.
558 */
559 if (bip->bli_flags & XFS_BLI_STALE_INODE) {
560 xfs_buf_item_done(bp);
561 xfs_buf_inode_iodone(bp);
562 ASSERT(list_empty(&bp->b_li_list));
563 } else {
564 xfs_trans_ail_delete(lip, SHUTDOWN_LOG_IO_ERROR);
565 xfs_buf_item_relse(bp);
566 ASSERT(bp->b_log_item == NULL);
567 }
568 xfs_buf_relse(bp);
569 return;
570 }
571
572 if (remove) {
573 /*
574 * We need to simulate an async IO failures here to ensure that
575 * the correct error completion is run on this buffer. This
576 * requires a reference to the buffer and for the buffer to be
577 * locked. We can safely pass ownership of the pin reference to
578 * the IO to ensure that nothing can free the buffer while we
579 * wait for the lock and then run the IO failure completion.
580 */
581 xfs_buf_lock(bp);
582 bp->b_flags |= XBF_ASYNC;
583 xfs_buf_ioend_fail(bp);
584 return;
585 }
586
587 /*
588 * BLI has no more active references - it will be moved to the AIL to
589 * manage the remaining BLI/buffer life cycle. There is nothing left for
590 * us to do here so drop the pin reference to the buffer.
591 */
592 xfs_buf_rele(bp);
593}
594
595STATIC uint
596xfs_buf_item_push(
597 struct xfs_log_item *lip,
598 struct list_head *buffer_list)
599{
600 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
601 struct xfs_buf *bp = bip->bli_buf;
602 uint rval = XFS_ITEM_SUCCESS;
603
604 if (xfs_buf_ispinned(bp))
605 return XFS_ITEM_PINNED;
606 if (!xfs_buf_trylock(bp)) {
607 /*
608 * If we have just raced with a buffer being pinned and it has
609 * been marked stale, we could end up stalling until someone else
610 * issues a log force to unpin the stale buffer. Check for the
611 * race condition here so xfsaild recognizes the buffer is pinned
612 * and queues a log force to move it along.
613 */
614 if (xfs_buf_ispinned(bp))
615 return XFS_ITEM_PINNED;
616 return XFS_ITEM_LOCKED;
617 }
618
619 ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
620
621 trace_xfs_buf_item_push(bip);
622
623 /* has a previous flush failed due to IO errors? */
624 if (bp->b_flags & XBF_WRITE_FAIL) {
625 xfs_buf_alert_ratelimited(bp, "XFS: Failing async write",
626 "Failing async write on buffer block 0x%llx. Retrying async write.",
627 (long long)xfs_buf_daddr(bp));
628 }
629
630 if (!xfs_buf_delwri_queue(bp, buffer_list))
631 rval = XFS_ITEM_FLUSHING;
632 xfs_buf_unlock(bp);
633 return rval;
634}
635
636/*
637 * Drop the buffer log item refcount and take appropriate action. This helper
638 * determines whether the bli must be freed or not, since a decrement to zero
639 * does not necessarily mean the bli is unused.
640 *
641 * Return true if the bli is freed, false otherwise.
642 */
643bool
644xfs_buf_item_put(
645 struct xfs_buf_log_item *bip)
646{
647 struct xfs_log_item *lip = &bip->bli_item;
648 bool aborted;
649 bool dirty;
650
651 /* drop the bli ref and return if it wasn't the last one */
652 if (!atomic_dec_and_test(&bip->bli_refcount))
653 return false;
654
655 /*
656 * We dropped the last ref and must free the item if clean or aborted.
657 * If the bli is dirty and non-aborted, the buffer was clean in the
658 * transaction but still awaiting writeback from previous changes. In
659 * that case, the bli is freed on buffer writeback completion.
660 */
661 aborted = test_bit(XFS_LI_ABORTED, &lip->li_flags) ||
662 xlog_is_shutdown(lip->li_log);
663 dirty = bip->bli_flags & XFS_BLI_DIRTY;
664 if (dirty && !aborted)
665 return false;
666
667 /*
668 * The bli is aborted or clean. An aborted item may be in the AIL
669 * regardless of dirty state. For example, consider an aborted
670 * transaction that invalidated a dirty bli and cleared the dirty
671 * state.
672 */
673 if (aborted)
674 xfs_trans_ail_delete(lip, 0);
675 xfs_buf_item_relse(bip->bli_buf);
676 return true;
677}
678
679/*
680 * Release the buffer associated with the buf log item. If there is no dirty
681 * logged data associated with the buffer recorded in the buf log item, then
682 * free the buf log item and remove the reference to it in the buffer.
683 *
684 * This call ignores the recursion count. It is only called when the buffer
685 * should REALLY be unlocked, regardless of the recursion count.
686 *
687 * We unconditionally drop the transaction's reference to the log item. If the
688 * item was logged, then another reference was taken when it was pinned, so we
689 * can safely drop the transaction reference now. This also allows us to avoid
690 * potential races with the unpin code freeing the bli by not referencing the
691 * bli after we've dropped the reference count.
692 *
693 * If the XFS_BLI_HOLD flag is set in the buf log item, then free the log item
694 * if necessary but do not unlock the buffer. This is for support of
695 * xfs_trans_bhold(). Make sure the XFS_BLI_HOLD field is cleared if we don't
696 * free the item.
697 */
698STATIC void
699xfs_buf_item_release(
700 struct xfs_log_item *lip)
701{
702 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
703 struct xfs_buf *bp = bip->bli_buf;
704 bool released;
705 bool hold = bip->bli_flags & XFS_BLI_HOLD;
706 bool stale = bip->bli_flags & XFS_BLI_STALE;
707#if defined(DEBUG) || defined(XFS_WARN)
708 bool ordered = bip->bli_flags & XFS_BLI_ORDERED;
709 bool dirty = bip->bli_flags & XFS_BLI_DIRTY;
710 bool aborted = test_bit(XFS_LI_ABORTED,
711 &lip->li_flags);
712#endif
713
714 trace_xfs_buf_item_release(bip);
715
716 /*
717 * The bli dirty state should match whether the blf has logged segments
718 * except for ordered buffers, where only the bli should be dirty.
719 */
720 ASSERT((!ordered && dirty == xfs_buf_item_dirty_format(bip)) ||
721 (ordered && dirty && !xfs_buf_item_dirty_format(bip)));
722 ASSERT(!stale || (bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
723
724 /*
725 * Clear the buffer's association with this transaction and
726 * per-transaction state from the bli, which has been copied above.
727 */
728 bp->b_transp = NULL;
729 bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD | XFS_BLI_ORDERED);
730
731 /*
732 * Unref the item and unlock the buffer unless held or stale. Stale
733 * buffers remain locked until final unpin unless the bli is freed by
734 * the unref call. The latter implies shutdown because buffer
735 * invalidation dirties the bli and transaction.
736 */
737 released = xfs_buf_item_put(bip);
738 if (hold || (stale && !released))
739 return;
740 ASSERT(!stale || aborted);
741 xfs_buf_relse(bp);
742}
743
744STATIC void
745xfs_buf_item_committing(
746 struct xfs_log_item *lip,
747 xfs_csn_t seq)
748{
749 return xfs_buf_item_release(lip);
750}
751
752/*
753 * This is called to find out where the oldest active copy of the
754 * buf log item in the on disk log resides now that the last log
755 * write of it completed at the given lsn.
756 * We always re-log all the dirty data in a buffer, so usually the
757 * latest copy in the on disk log is the only one that matters. For
758 * those cases we simply return the given lsn.
759 *
760 * The one exception to this is for buffers full of newly allocated
761 * inodes. These buffers are only relogged with the XFS_BLI_INODE_BUF
762 * flag set, indicating that only the di_next_unlinked fields from the
763 * inodes in the buffers will be replayed during recovery. If the
764 * original newly allocated inode images have not yet been flushed
765 * when the buffer is so relogged, then we need to make sure that we
766 * keep the old images in the 'active' portion of the log. We do this
767 * by returning the original lsn of that transaction here rather than
768 * the current one.
769 */
770STATIC xfs_lsn_t
771xfs_buf_item_committed(
772 struct xfs_log_item *lip,
773 xfs_lsn_t lsn)
774{
775 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
776
777 trace_xfs_buf_item_committed(bip);
778
779 if ((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && lip->li_lsn != 0)
780 return lip->li_lsn;
781 return lsn;
782}
783
784static const struct xfs_item_ops xfs_buf_item_ops = {
785 .iop_size = xfs_buf_item_size,
786 .iop_format = xfs_buf_item_format,
787 .iop_pin = xfs_buf_item_pin,
788 .iop_unpin = xfs_buf_item_unpin,
789 .iop_release = xfs_buf_item_release,
790 .iop_committing = xfs_buf_item_committing,
791 .iop_committed = xfs_buf_item_committed,
792 .iop_push = xfs_buf_item_push,
793};
794
795STATIC void
796xfs_buf_item_get_format(
797 struct xfs_buf_log_item *bip,
798 int count)
799{
800 ASSERT(bip->bli_formats == NULL);
801 bip->bli_format_count = count;
802
803 if (count == 1) {
804 bip->bli_formats = &bip->__bli_format;
805 return;
806 }
807
808 bip->bli_formats = kzalloc(count * sizeof(struct xfs_buf_log_format),
809 GFP_KERNEL | __GFP_NOFAIL);
810}
811
812STATIC void
813xfs_buf_item_free_format(
814 struct xfs_buf_log_item *bip)
815{
816 if (bip->bli_formats != &bip->__bli_format) {
817 kfree(bip->bli_formats);
818 bip->bli_formats = NULL;
819 }
820}
821
822/*
823 * Allocate a new buf log item to go with the given buffer.
824 * Set the buffer's b_log_item field to point to the new
825 * buf log item.
826 */
827int
828xfs_buf_item_init(
829 struct xfs_buf *bp,
830 struct xfs_mount *mp)
831{
832 struct xfs_buf_log_item *bip = bp->b_log_item;
833 int chunks;
834 int map_size;
835 int i;
836
837 /*
838 * Check to see if there is already a buf log item for
839 * this buffer. If we do already have one, there is
840 * nothing to do here so return.
841 */
842 ASSERT(bp->b_mount == mp);
843 if (bip) {
844 ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
845 ASSERT(!bp->b_transp);
846 ASSERT(bip->bli_buf == bp);
847 return 0;
848 }
849
850 bip = kmem_cache_zalloc(xfs_buf_item_cache, GFP_KERNEL | __GFP_NOFAIL);
851 xfs_log_item_init(mp, &bip->bli_item, XFS_LI_BUF, &xfs_buf_item_ops);
852 bip->bli_buf = bp;
853
854 /*
855 * chunks is the number of XFS_BLF_CHUNK size pieces the buffer
856 * can be divided into. Make sure not to truncate any pieces.
857 * map_size is the size of the bitmap needed to describe the
858 * chunks of the buffer.
859 *
860 * Discontiguous buffer support follows the layout of the underlying
861 * buffer. This makes the implementation as simple as possible.
862 */
863 xfs_buf_item_get_format(bip, bp->b_map_count);
864
865 for (i = 0; i < bip->bli_format_count; i++) {
866 chunks = DIV_ROUND_UP(BBTOB(bp->b_maps[i].bm_len),
867 XFS_BLF_CHUNK);
868 map_size = DIV_ROUND_UP(chunks, NBWORD);
869
870 if (map_size > XFS_BLF_DATAMAP_SIZE) {
871 kmem_cache_free(xfs_buf_item_cache, bip);
872 xfs_err(mp,
873 "buffer item dirty bitmap (%u uints) too small to reflect %u bytes!",
874 map_size,
875 BBTOB(bp->b_maps[i].bm_len));
876 return -EFSCORRUPTED;
877 }
878
879 bip->bli_formats[i].blf_type = XFS_LI_BUF;
880 bip->bli_formats[i].blf_blkno = bp->b_maps[i].bm_bn;
881 bip->bli_formats[i].blf_len = bp->b_maps[i].bm_len;
882 bip->bli_formats[i].blf_map_size = map_size;
883 }
884
885 bp->b_log_item = bip;
886 xfs_buf_hold(bp);
887 return 0;
888}
889
890
891/*
892 * Mark bytes first through last inclusive as dirty in the buf
893 * item's bitmap.
894 */
895static void
896xfs_buf_item_log_segment(
897 uint first,
898 uint last,
899 uint *map)
900{
901 uint first_bit;
902 uint last_bit;
903 uint bits_to_set;
904 uint bits_set;
905 uint word_num;
906 uint *wordp;
907 uint bit;
908 uint end_bit;
909 uint mask;
910
911 ASSERT(first < XFS_BLF_DATAMAP_SIZE * XFS_BLF_CHUNK * NBWORD);
912 ASSERT(last < XFS_BLF_DATAMAP_SIZE * XFS_BLF_CHUNK * NBWORD);
913
914 /*
915 * Convert byte offsets to bit numbers.
916 */
917 first_bit = first >> XFS_BLF_SHIFT;
918 last_bit = last >> XFS_BLF_SHIFT;
919
920 /*
921 * Calculate the total number of bits to be set.
922 */
923 bits_to_set = last_bit - first_bit + 1;
924
925 /*
926 * Get a pointer to the first word in the bitmap
927 * to set a bit in.
928 */
929 word_num = first_bit >> BIT_TO_WORD_SHIFT;
930 wordp = &map[word_num];
931
932 /*
933 * Calculate the starting bit in the first word.
934 */
935 bit = first_bit & (uint)(NBWORD - 1);
936
937 /*
938 * First set any bits in the first word of our range.
939 * If it starts at bit 0 of the word, it will be
940 * set below rather than here. That is what the variable
941 * bit tells us. The variable bits_set tracks the number
942 * of bits that have been set so far. End_bit is the number
943 * of the last bit to be set in this word plus one.
944 */
945 if (bit) {
946 end_bit = min(bit + bits_to_set, (uint)NBWORD);
947 mask = ((1U << (end_bit - bit)) - 1) << bit;
948 *wordp |= mask;
949 wordp++;
950 bits_set = end_bit - bit;
951 } else {
952 bits_set = 0;
953 }
954
955 /*
956 * Now set bits a whole word at a time that are between
957 * first_bit and last_bit.
958 */
959 while ((bits_to_set - bits_set) >= NBWORD) {
960 *wordp = 0xffffffff;
961 bits_set += NBWORD;
962 wordp++;
963 }
964
965 /*
966 * Finally, set any bits left to be set in one last partial word.
967 */
968 end_bit = bits_to_set - bits_set;
969 if (end_bit) {
970 mask = (1U << end_bit) - 1;
971 *wordp |= mask;
972 }
973}
974
975/*
976 * Mark bytes first through last inclusive as dirty in the buf
977 * item's bitmap.
978 */
979void
980xfs_buf_item_log(
981 struct xfs_buf_log_item *bip,
982 uint first,
983 uint last)
984{
985 int i;
986 uint start;
987 uint end;
988 struct xfs_buf *bp = bip->bli_buf;
989
990 /*
991 * walk each buffer segment and mark them dirty appropriately.
992 */
993 start = 0;
994 for (i = 0; i < bip->bli_format_count; i++) {
995 if (start > last)
996 break;
997 end = start + BBTOB(bp->b_maps[i].bm_len) - 1;
998
999 /* skip to the map that includes the first byte to log */
1000 if (first > end) {
1001 start += BBTOB(bp->b_maps[i].bm_len);
1002 continue;
1003 }
1004
1005 /*
1006 * Trim the range to this segment and mark it in the bitmap.
1007 * Note that we must convert buffer offsets to segment relative
1008 * offsets (e.g., the first byte of each segment is byte 0 of
1009 * that segment).
1010 */
1011 if (first < start)
1012 first = start;
1013 if (end > last)
1014 end = last;
1015 xfs_buf_item_log_segment(first - start, end - start,
1016 &bip->bli_formats[i].blf_data_map[0]);
1017
1018 start += BBTOB(bp->b_maps[i].bm_len);
1019 }
1020}
1021
1022
1023/*
1024 * Return true if the buffer has any ranges logged/dirtied by a transaction,
1025 * false otherwise.
1026 */
1027bool
1028xfs_buf_item_dirty_format(
1029 struct xfs_buf_log_item *bip)
1030{
1031 int i;
1032
1033 for (i = 0; i < bip->bli_format_count; i++) {
1034 if (!xfs_bitmap_empty(bip->bli_formats[i].blf_data_map,
1035 bip->bli_formats[i].blf_map_size))
1036 return true;
1037 }
1038
1039 return false;
1040}
1041
1042STATIC void
1043xfs_buf_item_free(
1044 struct xfs_buf_log_item *bip)
1045{
1046 xfs_buf_item_free_format(bip);
1047 kvfree(bip->bli_item.li_lv_shadow);
1048 kmem_cache_free(xfs_buf_item_cache, bip);
1049}
1050
1051/*
1052 * xfs_buf_item_relse() is called when the buf log item is no longer needed.
1053 */
1054void
1055xfs_buf_item_relse(
1056 struct xfs_buf *bp)
1057{
1058 struct xfs_buf_log_item *bip = bp->b_log_item;
1059
1060 trace_xfs_buf_item_relse(bp, _RET_IP_);
1061 ASSERT(!test_bit(XFS_LI_IN_AIL, &bip->bli_item.li_flags));
1062
1063 if (atomic_read(&bip->bli_refcount))
1064 return;
1065 bp->b_log_item = NULL;
1066 xfs_buf_rele(bp);
1067 xfs_buf_item_free(bip);
1068}
1069
1070void
1071xfs_buf_item_done(
1072 struct xfs_buf *bp)
1073{
1074 /*
1075 * If we are forcibly shutting down, this may well be off the AIL
1076 * already. That's because we simulate the log-committed callbacks to
1077 * unpin these buffers. Or we may never have put this item on AIL
1078 * because of the transaction was aborted forcibly.
1079 * xfs_trans_ail_delete() takes care of these.
1080 *
1081 * Either way, AIL is useless if we're forcing a shutdown.
1082 *
1083 * Note that log recovery writes might have buffer items that are not on
1084 * the AIL even when the file system is not shut down.
1085 */
1086 xfs_trans_ail_delete(&bp->b_log_item->bli_item,
1087 (bp->b_flags & _XBF_LOGRECOVERY) ? 0 :
1088 SHUTDOWN_CORRUPT_INCORE);
1089 xfs_buf_item_relse(bp);
1090}