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 #include "xfs_error.h"
26
27
28 struct kmem_cache *xfs_buf_item_cache;
29
BUF_ITEM(struct xfs_log_item * lip)30 static inline struct xfs_buf_log_item *BUF_ITEM(struct xfs_log_item *lip)
31 {
32 return container_of(lip, struct xfs_buf_log_item, bli_item);
33 }
34
35 /* Is this log iovec plausibly large enough to contain the buffer log format? */
36 bool
xfs_buf_log_check_iovec(struct xfs_log_iovec * iovec)37 xfs_buf_log_check_iovec(
38 struct xfs_log_iovec *iovec)
39 {
40 struct xfs_buf_log_format *blfp = iovec->i_addr;
41 char *bmp_end;
42 char *item_end;
43
44 if (offsetof(struct xfs_buf_log_format, blf_data_map) > iovec->i_len)
45 return false;
46
47 item_end = (char *)iovec->i_addr + iovec->i_len;
48 bmp_end = (char *)&blfp->blf_data_map[blfp->blf_map_size];
49 return bmp_end <= item_end;
50 }
51
52 static inline int
xfs_buf_log_format_size(struct xfs_buf_log_format * blfp)53 xfs_buf_log_format_size(
54 struct xfs_buf_log_format *blfp)
55 {
56 return offsetof(struct xfs_buf_log_format, blf_data_map) +
57 (blfp->blf_map_size * sizeof(blfp->blf_data_map[0]));
58 }
59
60 /*
61 * Return the number of log iovecs and space needed to log the given buf log
62 * item segment.
63 *
64 * It calculates this as 1 iovec for the buf log format structure and 1 for each
65 * stretch of non-contiguous chunks to be logged. Contiguous chunks are logged
66 * in a single iovec.
67 */
68 STATIC void
xfs_buf_item_size_segment(struct xfs_buf_log_item * bip,struct xfs_buf_log_format * blfp,uint offset,int * nvecs,int * nbytes)69 xfs_buf_item_size_segment(
70 struct xfs_buf_log_item *bip,
71 struct xfs_buf_log_format *blfp,
72 uint offset,
73 int *nvecs,
74 int *nbytes)
75 {
76 int first_bit;
77 int nbits;
78
79 first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0);
80 if (first_bit == -1)
81 return;
82
83 (*nvecs)++;
84 *nbytes += xfs_buf_log_format_size(blfp);
85
86 do {
87 nbits = xfs_contig_bits(blfp->blf_data_map,
88 blfp->blf_map_size, first_bit);
89 ASSERT(nbits > 0);
90 (*nvecs)++;
91 *nbytes += nbits * XFS_BLF_CHUNK;
92
93 /*
94 * This takes the bit number to start looking from and
95 * returns the next set bit from there. It returns -1
96 * if there are no more bits set or the start bit is
97 * beyond the end of the bitmap.
98 */
99 first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
100 (uint)first_bit + nbits + 1);
101 } while (first_bit != -1);
102
103 return;
104 }
105
106 /*
107 * Return the number of log iovecs and space needed to log the given buf log
108 * item.
109 *
110 * Discontiguous buffers need a format structure per region that is being
111 * logged. This makes the changes in the buffer appear to log recovery as though
112 * they came from separate buffers, just like would occur if multiple buffers
113 * were used instead of a single discontiguous buffer. This enables
114 * discontiguous buffers to be in-memory constructs, completely transparent to
115 * what ends up on disk.
116 *
117 * If the XFS_BLI_STALE flag has been set, then log nothing but the buf log
118 * format structures. If the item has previously been logged and has dirty
119 * regions, we do not relog them in stale buffers. This has the effect of
120 * reducing the size of the relogged item by the amount of dirty data tracked
121 * by the log item. This can result in the committing transaction reducing the
122 * amount of space being consumed by the CIL.
123 */
124 STATIC void
xfs_buf_item_size(struct xfs_log_item * lip,int * nvecs,int * nbytes)125 xfs_buf_item_size(
126 struct xfs_log_item *lip,
127 int *nvecs,
128 int *nbytes)
129 {
130 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
131 struct xfs_buf *bp = bip->bli_buf;
132 int i;
133 int bytes;
134 uint offset = 0;
135
136 ASSERT(atomic_read(&bip->bli_refcount) > 0);
137 if (bip->bli_flags & XFS_BLI_STALE) {
138 /*
139 * The buffer is stale, so all we need to log is the buf log
140 * format structure with the cancel flag in it as we are never
141 * going to replay the changes tracked in the log item.
142 */
143 trace_xfs_buf_item_size_stale(bip);
144 ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
145 *nvecs += bip->bli_format_count;
146 for (i = 0; i < bip->bli_format_count; i++) {
147 *nbytes += xfs_buf_log_format_size(&bip->bli_formats[i]);
148 }
149 return;
150 }
151
152 ASSERT(bip->bli_flags & XFS_BLI_LOGGED);
153
154 if (bip->bli_flags & XFS_BLI_ORDERED) {
155 /*
156 * The buffer has been logged just to order it. It is not being
157 * included in the transaction commit, so no vectors are used at
158 * all.
159 */
160 trace_xfs_buf_item_size_ordered(bip);
161 *nvecs = XFS_LOG_VEC_ORDERED;
162 return;
163 }
164
165 /*
166 * The vector count is based on the number of buffer vectors we have
167 * dirty bits in. This will only be greater than one when we have a
168 * compound buffer with more than one segment dirty. Hence for compound
169 * buffers we need to track which segment the dirty bits correspond to,
170 * and when we move from one segment to the next increment the vector
171 * count for the extra buf log format structure that will need to be
172 * written.
173 */
174 bytes = 0;
175 for (i = 0; i < bip->bli_format_count; i++) {
176 xfs_buf_item_size_segment(bip, &bip->bli_formats[i], offset,
177 nvecs, &bytes);
178 offset += BBTOB(bp->b_maps[i].bm_len);
179 }
180
181 /*
182 * Round up the buffer size required to minimise the number of memory
183 * allocations that need to be done as this item grows when relogged by
184 * repeated modifications.
185 */
186 *nbytes = round_up(bytes, 512);
187 trace_xfs_buf_item_size(bip);
188 }
189
190 static inline void
xfs_buf_item_copy_iovec(struct xfs_log_vec * lv,struct xfs_log_iovec ** vecp,struct xfs_buf * bp,uint offset,int first_bit,uint nbits)191 xfs_buf_item_copy_iovec(
192 struct xfs_log_vec *lv,
193 struct xfs_log_iovec **vecp,
194 struct xfs_buf *bp,
195 uint offset,
196 int first_bit,
197 uint nbits)
198 {
199 offset += first_bit * XFS_BLF_CHUNK;
200 xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_BCHUNK,
201 xfs_buf_offset(bp, offset),
202 nbits * XFS_BLF_CHUNK);
203 }
204
205 static void
xfs_buf_item_format_segment(struct xfs_buf_log_item * bip,struct xfs_log_vec * lv,struct xfs_log_iovec ** vecp,uint offset,struct xfs_buf_log_format * blfp)206 xfs_buf_item_format_segment(
207 struct xfs_buf_log_item *bip,
208 struct xfs_log_vec *lv,
209 struct xfs_log_iovec **vecp,
210 uint offset,
211 struct xfs_buf_log_format *blfp)
212 {
213 struct xfs_buf *bp = bip->bli_buf;
214 uint base_size;
215 int first_bit;
216 uint nbits;
217
218 /* copy the flags across from the base format item */
219 blfp->blf_flags = bip->__bli_format.blf_flags;
220
221 /*
222 * Base size is the actual size of the ondisk structure - it reflects
223 * the actual size of the dirty bitmap rather than the size of the in
224 * memory structure.
225 */
226 base_size = xfs_buf_log_format_size(blfp);
227
228 first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size, 0);
229 if (!(bip->bli_flags & XFS_BLI_STALE) && first_bit == -1) {
230 /*
231 * If the map is not be dirty in the transaction, mark
232 * the size as zero and do not advance the vector pointer.
233 */
234 return;
235 }
236
237 blfp = xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_BFORMAT, blfp, base_size);
238 blfp->blf_size = 1;
239
240 if (bip->bli_flags & XFS_BLI_STALE) {
241 /*
242 * The buffer is stale, so all we need to log
243 * is the buf log format structure with the
244 * cancel flag in it.
245 */
246 trace_xfs_buf_item_format_stale(bip);
247 ASSERT(blfp->blf_flags & XFS_BLF_CANCEL);
248 return;
249 }
250
251
252 /*
253 * Fill in an iovec for each set of contiguous chunks.
254 */
255 do {
256 ASSERT(first_bit >= 0);
257 nbits = xfs_contig_bits(blfp->blf_data_map,
258 blfp->blf_map_size, first_bit);
259 ASSERT(nbits > 0);
260 xfs_buf_item_copy_iovec(lv, vecp, bp, offset,
261 first_bit, nbits);
262 blfp->blf_size++;
263
264 /*
265 * This takes the bit number to start looking from and
266 * returns the next set bit from there. It returns -1
267 * if there are no more bits set or the start bit is
268 * beyond the end of the bitmap.
269 */
270 first_bit = xfs_next_bit(blfp->blf_data_map, blfp->blf_map_size,
271 (uint)first_bit + nbits + 1);
272 } while (first_bit != -1);
273
274 return;
275 }
276
277 /*
278 * This is called to fill in the vector of log iovecs for the
279 * given log buf item. It fills the first entry with a buf log
280 * format structure, and the rest point to contiguous chunks
281 * within the buffer.
282 */
283 STATIC void
xfs_buf_item_format(struct xfs_log_item * lip,struct xfs_log_vec * lv)284 xfs_buf_item_format(
285 struct xfs_log_item *lip,
286 struct xfs_log_vec *lv)
287 {
288 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
289 struct xfs_buf *bp = bip->bli_buf;
290 struct xfs_log_iovec *vecp = NULL;
291 uint offset = 0;
292 int i;
293
294 ASSERT(atomic_read(&bip->bli_refcount) > 0);
295 ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
296 (bip->bli_flags & XFS_BLI_STALE));
297 ASSERT((bip->bli_flags & XFS_BLI_STALE) ||
298 (xfs_blft_from_flags(&bip->__bli_format) > XFS_BLFT_UNKNOWN_BUF
299 && xfs_blft_from_flags(&bip->__bli_format) < XFS_BLFT_MAX_BUF));
300 ASSERT(!(bip->bli_flags & XFS_BLI_ORDERED) ||
301 (bip->bli_flags & XFS_BLI_STALE));
302
303
304 /*
305 * If it is an inode buffer, transfer the in-memory state to the
306 * format flags and clear the in-memory state.
307 *
308 * For buffer based inode allocation, we do not transfer
309 * this state if the inode buffer allocation has not yet been committed
310 * to the log as setting the XFS_BLI_INODE_BUF flag will prevent
311 * correct replay of the inode allocation.
312 *
313 * For icreate item based inode allocation, the buffers aren't written
314 * to the journal during allocation, and hence we should always tag the
315 * buffer as an inode buffer so that the correct unlinked list replay
316 * occurs during recovery.
317 */
318 if (bip->bli_flags & XFS_BLI_INODE_BUF) {
319 if (xfs_has_v3inodes(lip->li_log->l_mp) ||
320 !((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) &&
321 xfs_log_item_in_current_chkpt(lip)))
322 bip->__bli_format.blf_flags |= XFS_BLF_INODE_BUF;
323 bip->bli_flags &= ~XFS_BLI_INODE_BUF;
324 }
325
326 for (i = 0; i < bip->bli_format_count; i++) {
327 xfs_buf_item_format_segment(bip, lv, &vecp, offset,
328 &bip->bli_formats[i]);
329 offset += BBTOB(bp->b_maps[i].bm_len);
330 }
331
332 /*
333 * Check to make sure everything is consistent.
334 */
335 trace_xfs_buf_item_format(bip);
336 }
337
338 /*
339 * This is called to pin the buffer associated with the buf log item in memory
340 * so it cannot be written out.
341 *
342 * We take a reference to the buffer log item here so that the BLI life cycle
343 * extends at least until the buffer is unpinned via xfs_buf_item_unpin() and
344 * inserted into the AIL.
345 *
346 * We also need to take a reference to the buffer itself as the BLI unpin
347 * processing requires accessing the buffer after the BLI has dropped the final
348 * BLI reference. See xfs_buf_item_unpin() for an explanation.
349 * If unpins race to drop the final BLI reference and only the
350 * BLI owns a reference to the buffer, then the loser of the race can have the
351 * buffer fgreed from under it (e.g. on shutdown). Taking a buffer reference per
352 * pin count ensures the life cycle of the buffer extends for as
353 * long as we hold the buffer pin reference in xfs_buf_item_unpin().
354 */
355 STATIC void
xfs_buf_item_pin(struct xfs_log_item * lip)356 xfs_buf_item_pin(
357 struct xfs_log_item *lip)
358 {
359 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
360
361 ASSERT(atomic_read(&bip->bli_refcount) > 0);
362 ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
363 (bip->bli_flags & XFS_BLI_ORDERED) ||
364 (bip->bli_flags & XFS_BLI_STALE));
365
366 trace_xfs_buf_item_pin(bip);
367
368 xfs_buf_hold(bip->bli_buf);
369 atomic_inc(&bip->bli_refcount);
370 atomic_inc(&bip->bli_buf->b_pin_count);
371 }
372
373 /*
374 * This is called to unpin the buffer associated with the buf log item which was
375 * previously pinned with a call to xfs_buf_item_pin(). We enter this function
376 * with a buffer pin count, a buffer reference and a BLI reference.
377 *
378 * We must drop the BLI reference before we unpin the buffer because the AIL
379 * doesn't acquire a BLI reference whenever it accesses it. Therefore if the
380 * refcount drops to zero, the bli could still be AIL resident and the buffer
381 * submitted for I/O at any point before we return. This can result in IO
382 * completion freeing the buffer while we are still trying to access it here.
383 * This race condition can also occur in shutdown situations where we abort and
384 * unpin buffers from contexts other that journal IO completion.
385 *
386 * Hence we have to hold a buffer reference per pin count to ensure that the
387 * buffer cannot be freed until we have finished processing the unpin operation.
388 * The reference is taken in xfs_buf_item_pin(), and we must hold it until we
389 * are done processing the buffer state. In the case of an abort (remove =
390 * true) then we re-use the current pin reference as the IO reference we hand
391 * off to IO failure handling.
392 */
393 STATIC void
xfs_buf_item_unpin(struct xfs_log_item * lip,int remove)394 xfs_buf_item_unpin(
395 struct xfs_log_item *lip,
396 int remove)
397 {
398 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
399 struct xfs_buf *bp = bip->bli_buf;
400 int stale = bip->bli_flags & XFS_BLI_STALE;
401 int freed;
402
403 ASSERT(bp->b_log_item == bip);
404 ASSERT(atomic_read(&bip->bli_refcount) > 0);
405
406 trace_xfs_buf_item_unpin(bip);
407
408 freed = atomic_dec_and_test(&bip->bli_refcount);
409 if (atomic_dec_and_test(&bp->b_pin_count))
410 wake_up_all(&bp->b_waiters);
411
412 /*
413 * Nothing to do but drop the buffer pin reference if the BLI is
414 * still active.
415 */
416 if (!freed) {
417 xfs_buf_rele(bp);
418 return;
419 }
420
421 if (stale) {
422 ASSERT(bip->bli_flags & XFS_BLI_STALE);
423 ASSERT(xfs_buf_islocked(bp));
424 ASSERT(bp->b_flags & XBF_STALE);
425 ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
426 ASSERT(list_empty(&lip->li_trans));
427 ASSERT(!bp->b_transp);
428
429 trace_xfs_buf_item_unpin_stale(bip);
430
431 /*
432 * The buffer has been locked and referenced since it was marked
433 * stale so we own both lock and reference exclusively here. We
434 * do not need the pin reference any more, so drop it now so
435 * that we only have one reference to drop once item completion
436 * processing is complete.
437 */
438 xfs_buf_rele(bp);
439
440 /*
441 * If we get called here because of an IO error, we may or may
442 * not have the item on the AIL. xfs_trans_ail_delete() will
443 * take care of that situation. xfs_trans_ail_delete() drops
444 * the AIL lock.
445 */
446 if (bip->bli_flags & XFS_BLI_STALE_INODE) {
447 xfs_buf_item_done(bp);
448 xfs_buf_inode_iodone(bp);
449 ASSERT(list_empty(&bp->b_li_list));
450 } else {
451 xfs_trans_ail_delete(lip, SHUTDOWN_LOG_IO_ERROR);
452 xfs_buf_item_relse(bp);
453 ASSERT(bp->b_log_item == NULL);
454 }
455 xfs_buf_relse(bp);
456 return;
457 }
458
459 if (remove) {
460 /*
461 * We need to simulate an async IO failures here to ensure that
462 * the correct error completion is run on this buffer. This
463 * requires a reference to the buffer and for the buffer to be
464 * locked. We can safely pass ownership of the pin reference to
465 * the IO to ensure that nothing can free the buffer while we
466 * wait for the lock and then run the IO failure completion.
467 */
468 xfs_buf_lock(bp);
469 bp->b_flags |= XBF_ASYNC;
470 xfs_buf_ioend_fail(bp);
471 return;
472 }
473
474 /*
475 * BLI has no more active references - it will be moved to the AIL to
476 * manage the remaining BLI/buffer life cycle. There is nothing left for
477 * us to do here so drop the pin reference to the buffer.
478 */
479 xfs_buf_rele(bp);
480 }
481
482 STATIC uint
xfs_buf_item_push(struct xfs_log_item * lip,struct list_head * buffer_list)483 xfs_buf_item_push(
484 struct xfs_log_item *lip,
485 struct list_head *buffer_list)
486 {
487 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
488 struct xfs_buf *bp = bip->bli_buf;
489 uint rval = XFS_ITEM_SUCCESS;
490
491 if (xfs_buf_ispinned(bp))
492 return XFS_ITEM_PINNED;
493 if (!xfs_buf_trylock(bp)) {
494 /*
495 * If we have just raced with a buffer being pinned and it has
496 * been marked stale, we could end up stalling until someone else
497 * issues a log force to unpin the stale buffer. Check for the
498 * race condition here so xfsaild recognizes the buffer is pinned
499 * and queues a log force to move it along.
500 */
501 if (xfs_buf_ispinned(bp))
502 return XFS_ITEM_PINNED;
503 return XFS_ITEM_LOCKED;
504 }
505
506 ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
507
508 trace_xfs_buf_item_push(bip);
509
510 /* has a previous flush failed due to IO errors? */
511 if (bp->b_flags & XBF_WRITE_FAIL) {
512 xfs_buf_alert_ratelimited(bp, "XFS: Failing async write",
513 "Failing async write on buffer block 0x%llx. Retrying async write.",
514 (long long)xfs_buf_daddr(bp));
515 }
516
517 if (!xfs_buf_delwri_queue(bp, buffer_list))
518 rval = XFS_ITEM_FLUSHING;
519 xfs_buf_unlock(bp);
520 return rval;
521 }
522
523 /*
524 * Drop the buffer log item refcount and take appropriate action. This helper
525 * determines whether the bli must be freed or not, since a decrement to zero
526 * does not necessarily mean the bli is unused.
527 *
528 * Return true if the bli is freed, false otherwise.
529 */
530 bool
xfs_buf_item_put(struct xfs_buf_log_item * bip)531 xfs_buf_item_put(
532 struct xfs_buf_log_item *bip)
533 {
534 struct xfs_log_item *lip = &bip->bli_item;
535 bool aborted;
536 bool dirty;
537
538 /* drop the bli ref and return if it wasn't the last one */
539 if (!atomic_dec_and_test(&bip->bli_refcount))
540 return false;
541
542 /*
543 * We dropped the last ref and must free the item if clean or aborted.
544 * If the bli is dirty and non-aborted, the buffer was clean in the
545 * transaction but still awaiting writeback from previous changes. In
546 * that case, the bli is freed on buffer writeback completion.
547 */
548 aborted = test_bit(XFS_LI_ABORTED, &lip->li_flags) ||
549 xlog_is_shutdown(lip->li_log);
550 dirty = bip->bli_flags & XFS_BLI_DIRTY;
551 if (dirty && !aborted)
552 return false;
553
554 /*
555 * The bli is aborted or clean. An aborted item may be in the AIL
556 * regardless of dirty state. For example, consider an aborted
557 * transaction that invalidated a dirty bli and cleared the dirty
558 * state.
559 */
560 if (aborted)
561 xfs_trans_ail_delete(lip, 0);
562 xfs_buf_item_relse(bip->bli_buf);
563 return true;
564 }
565
566 /*
567 * Release the buffer associated with the buf log item. If there is no dirty
568 * logged data associated with the buffer recorded in the buf log item, then
569 * free the buf log item and remove the reference to it in the buffer.
570 *
571 * This call ignores the recursion count. It is only called when the buffer
572 * should REALLY be unlocked, regardless of the recursion count.
573 *
574 * We unconditionally drop the transaction's reference to the log item. If the
575 * item was logged, then another reference was taken when it was pinned, so we
576 * can safely drop the transaction reference now. This also allows us to avoid
577 * potential races with the unpin code freeing the bli by not referencing the
578 * bli after we've dropped the reference count.
579 *
580 * If the XFS_BLI_HOLD flag is set in the buf log item, then free the log item
581 * if necessary but do not unlock the buffer. This is for support of
582 * xfs_trans_bhold(). Make sure the XFS_BLI_HOLD field is cleared if we don't
583 * free the item.
584 */
585 STATIC void
xfs_buf_item_release(struct xfs_log_item * lip)586 xfs_buf_item_release(
587 struct xfs_log_item *lip)
588 {
589 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
590 struct xfs_buf *bp = bip->bli_buf;
591 bool released;
592 bool hold = bip->bli_flags & XFS_BLI_HOLD;
593 bool stale = bip->bli_flags & XFS_BLI_STALE;
594 #if defined(DEBUG) || defined(XFS_WARN)
595 bool ordered = bip->bli_flags & XFS_BLI_ORDERED;
596 bool dirty = bip->bli_flags & XFS_BLI_DIRTY;
597 bool aborted = test_bit(XFS_LI_ABORTED,
598 &lip->li_flags);
599 #endif
600
601 trace_xfs_buf_item_release(bip);
602
603 /*
604 * The bli dirty state should match whether the blf has logged segments
605 * except for ordered buffers, where only the bli should be dirty.
606 */
607 ASSERT((!ordered && dirty == xfs_buf_item_dirty_format(bip)) ||
608 (ordered && dirty && !xfs_buf_item_dirty_format(bip)));
609 ASSERT(!stale || (bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
610
611 /*
612 * Clear the buffer's association with this transaction and
613 * per-transaction state from the bli, which has been copied above.
614 */
615 bp->b_transp = NULL;
616 bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD | XFS_BLI_ORDERED);
617
618 /*
619 * Unref the item and unlock the buffer unless held or stale. Stale
620 * buffers remain locked until final unpin unless the bli is freed by
621 * the unref call. The latter implies shutdown because buffer
622 * invalidation dirties the bli and transaction.
623 */
624 released = xfs_buf_item_put(bip);
625 if (hold || (stale && !released))
626 return;
627 ASSERT(!stale || aborted);
628 xfs_buf_relse(bp);
629 }
630
631 STATIC void
xfs_buf_item_committing(struct xfs_log_item * lip,xfs_csn_t seq)632 xfs_buf_item_committing(
633 struct xfs_log_item *lip,
634 xfs_csn_t seq)
635 {
636 return xfs_buf_item_release(lip);
637 }
638
639 /*
640 * This is called to find out where the oldest active copy of the
641 * buf log item in the on disk log resides now that the last log
642 * write of it completed at the given lsn.
643 * We always re-log all the dirty data in a buffer, so usually the
644 * latest copy in the on disk log is the only one that matters. For
645 * those cases we simply return the given lsn.
646 *
647 * The one exception to this is for buffers full of newly allocated
648 * inodes. These buffers are only relogged with the XFS_BLI_INODE_BUF
649 * flag set, indicating that only the di_next_unlinked fields from the
650 * inodes in the buffers will be replayed during recovery. If the
651 * original newly allocated inode images have not yet been flushed
652 * when the buffer is so relogged, then we need to make sure that we
653 * keep the old images in the 'active' portion of the log. We do this
654 * by returning the original lsn of that transaction here rather than
655 * the current one.
656 */
657 STATIC xfs_lsn_t
xfs_buf_item_committed(struct xfs_log_item * lip,xfs_lsn_t lsn)658 xfs_buf_item_committed(
659 struct xfs_log_item *lip,
660 xfs_lsn_t lsn)
661 {
662 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
663
664 trace_xfs_buf_item_committed(bip);
665
666 if ((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && lip->li_lsn != 0)
667 return lip->li_lsn;
668 return lsn;
669 }
670
671 #ifdef DEBUG_EXPENSIVE
672 static int
xfs_buf_item_precommit(struct xfs_trans * tp,struct xfs_log_item * lip)673 xfs_buf_item_precommit(
674 struct xfs_trans *tp,
675 struct xfs_log_item *lip)
676 {
677 struct xfs_buf_log_item *bip = BUF_ITEM(lip);
678 struct xfs_buf *bp = bip->bli_buf;
679 struct xfs_mount *mp = bp->b_mount;
680 xfs_failaddr_t fa;
681
682 if (!bp->b_ops || !bp->b_ops->verify_struct)
683 return 0;
684 if (bip->bli_flags & XFS_BLI_STALE)
685 return 0;
686
687 fa = bp->b_ops->verify_struct(bp);
688 if (fa) {
689 xfs_buf_verifier_error(bp, -EFSCORRUPTED, bp->b_ops->name,
690 bp->b_addr, BBTOB(bp->b_length), fa);
691 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
692 ASSERT(fa == NULL);
693 }
694
695 return 0;
696 }
697 #else
698 # define xfs_buf_item_precommit NULL
699 #endif
700
701 static const struct xfs_item_ops xfs_buf_item_ops = {
702 .iop_size = xfs_buf_item_size,
703 .iop_precommit = xfs_buf_item_precommit,
704 .iop_format = xfs_buf_item_format,
705 .iop_pin = xfs_buf_item_pin,
706 .iop_unpin = xfs_buf_item_unpin,
707 .iop_release = xfs_buf_item_release,
708 .iop_committing = xfs_buf_item_committing,
709 .iop_committed = xfs_buf_item_committed,
710 .iop_push = xfs_buf_item_push,
711 };
712
713 STATIC void
xfs_buf_item_get_format(struct xfs_buf_log_item * bip,int count)714 xfs_buf_item_get_format(
715 struct xfs_buf_log_item *bip,
716 int count)
717 {
718 ASSERT(bip->bli_formats == NULL);
719 bip->bli_format_count = count;
720
721 if (count == 1) {
722 bip->bli_formats = &bip->__bli_format;
723 return;
724 }
725
726 bip->bli_formats = kzalloc(count * sizeof(struct xfs_buf_log_format),
727 GFP_KERNEL | __GFP_NOFAIL);
728 }
729
730 STATIC void
xfs_buf_item_free_format(struct xfs_buf_log_item * bip)731 xfs_buf_item_free_format(
732 struct xfs_buf_log_item *bip)
733 {
734 if (bip->bli_formats != &bip->__bli_format) {
735 kfree(bip->bli_formats);
736 bip->bli_formats = NULL;
737 }
738 }
739
740 /*
741 * Allocate a new buf log item to go with the given buffer.
742 * Set the buffer's b_log_item field to point to the new
743 * buf log item.
744 */
745 int
xfs_buf_item_init(struct xfs_buf * bp,struct xfs_mount * mp)746 xfs_buf_item_init(
747 struct xfs_buf *bp,
748 struct xfs_mount *mp)
749 {
750 struct xfs_buf_log_item *bip = bp->b_log_item;
751 int chunks;
752 int map_size;
753 int i;
754
755 /*
756 * Check to see if there is already a buf log item for
757 * this buffer. If we do already have one, there is
758 * nothing to do here so return.
759 */
760 ASSERT(bp->b_mount == mp);
761 if (bip) {
762 ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
763 ASSERT(!bp->b_transp);
764 ASSERT(bip->bli_buf == bp);
765 return 0;
766 }
767
768 bip = kmem_cache_zalloc(xfs_buf_item_cache, GFP_KERNEL | __GFP_NOFAIL);
769 xfs_log_item_init(mp, &bip->bli_item, XFS_LI_BUF, &xfs_buf_item_ops);
770 bip->bli_buf = bp;
771
772 /*
773 * chunks is the number of XFS_BLF_CHUNK size pieces the buffer
774 * can be divided into. Make sure not to truncate any pieces.
775 * map_size is the size of the bitmap needed to describe the
776 * chunks of the buffer.
777 *
778 * Discontiguous buffer support follows the layout of the underlying
779 * buffer. This makes the implementation as simple as possible.
780 */
781 xfs_buf_item_get_format(bip, bp->b_map_count);
782
783 for (i = 0; i < bip->bli_format_count; i++) {
784 chunks = DIV_ROUND_UP(BBTOB(bp->b_maps[i].bm_len),
785 XFS_BLF_CHUNK);
786 map_size = DIV_ROUND_UP(chunks, NBWORD);
787
788 if (map_size > XFS_BLF_DATAMAP_SIZE) {
789 kmem_cache_free(xfs_buf_item_cache, bip);
790 xfs_err(mp,
791 "buffer item dirty bitmap (%u uints) too small to reflect %u bytes!",
792 map_size,
793 BBTOB(bp->b_maps[i].bm_len));
794 return -EFSCORRUPTED;
795 }
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 bp->b_log_item = bip;
804 xfs_buf_hold(bp);
805 return 0;
806 }
807
808
809 /*
810 * Mark bytes first through last inclusive as dirty in the buf
811 * item's bitmap.
812 */
813 static void
xfs_buf_item_log_segment(uint first,uint last,uint * map)814 xfs_buf_item_log_segment(
815 uint first,
816 uint last,
817 uint *map)
818 {
819 uint first_bit;
820 uint last_bit;
821 uint bits_to_set;
822 uint bits_set;
823 uint word_num;
824 uint *wordp;
825 uint bit;
826 uint end_bit;
827 uint mask;
828
829 ASSERT(first < XFS_BLF_DATAMAP_SIZE * XFS_BLF_CHUNK * NBWORD);
830 ASSERT(last < XFS_BLF_DATAMAP_SIZE * XFS_BLF_CHUNK * NBWORD);
831
832 /*
833 * Convert byte offsets to bit numbers.
834 */
835 first_bit = first >> XFS_BLF_SHIFT;
836 last_bit = last >> XFS_BLF_SHIFT;
837
838 /*
839 * Calculate the total number of bits to be set.
840 */
841 bits_to_set = last_bit - first_bit + 1;
842
843 /*
844 * Get a pointer to the first word in the bitmap
845 * to set a bit in.
846 */
847 word_num = first_bit >> BIT_TO_WORD_SHIFT;
848 wordp = &map[word_num];
849
850 /*
851 * Calculate the starting bit in the first word.
852 */
853 bit = first_bit & (uint)(NBWORD - 1);
854
855 /*
856 * First set any bits in the first word of our range.
857 * If it starts at bit 0 of the word, it will be
858 * set below rather than here. That is what the variable
859 * bit tells us. The variable bits_set tracks the number
860 * of bits that have been set so far. End_bit is the number
861 * of the last bit to be set in this word plus one.
862 */
863 if (bit) {
864 end_bit = min(bit + bits_to_set, (uint)NBWORD);
865 mask = ((1U << (end_bit - bit)) - 1) << bit;
866 *wordp |= mask;
867 wordp++;
868 bits_set = end_bit - bit;
869 } else {
870 bits_set = 0;
871 }
872
873 /*
874 * Now set bits a whole word at a time that are between
875 * first_bit and last_bit.
876 */
877 while ((bits_to_set - bits_set) >= NBWORD) {
878 *wordp = 0xffffffff;
879 bits_set += NBWORD;
880 wordp++;
881 }
882
883 /*
884 * Finally, set any bits left to be set in one last partial word.
885 */
886 end_bit = bits_to_set - bits_set;
887 if (end_bit) {
888 mask = (1U << end_bit) - 1;
889 *wordp |= mask;
890 }
891 }
892
893 /*
894 * Mark bytes first through last inclusive as dirty in the buf
895 * item's bitmap.
896 */
897 void
xfs_buf_item_log(struct xfs_buf_log_item * bip,uint first,uint last)898 xfs_buf_item_log(
899 struct xfs_buf_log_item *bip,
900 uint first,
901 uint last)
902 {
903 int i;
904 uint start;
905 uint end;
906 struct xfs_buf *bp = bip->bli_buf;
907
908 /*
909 * walk each buffer segment and mark them dirty appropriately.
910 */
911 start = 0;
912 for (i = 0; i < bip->bli_format_count; i++) {
913 if (start > last)
914 break;
915 end = start + BBTOB(bp->b_maps[i].bm_len) - 1;
916
917 /* skip to the map that includes the first byte to log */
918 if (first > end) {
919 start += BBTOB(bp->b_maps[i].bm_len);
920 continue;
921 }
922
923 /*
924 * Trim the range to this segment and mark it in the bitmap.
925 * Note that we must convert buffer offsets to segment relative
926 * offsets (e.g., the first byte of each segment is byte 0 of
927 * that segment).
928 */
929 if (first < start)
930 first = start;
931 if (end > last)
932 end = last;
933 xfs_buf_item_log_segment(first - start, end - start,
934 &bip->bli_formats[i].blf_data_map[0]);
935
936 start += BBTOB(bp->b_maps[i].bm_len);
937 }
938 }
939
940
941 /*
942 * Return true if the buffer has any ranges logged/dirtied by a transaction,
943 * false otherwise.
944 */
945 bool
xfs_buf_item_dirty_format(struct xfs_buf_log_item * bip)946 xfs_buf_item_dirty_format(
947 struct xfs_buf_log_item *bip)
948 {
949 int i;
950
951 for (i = 0; i < bip->bli_format_count; i++) {
952 if (!xfs_bitmap_empty(bip->bli_formats[i].blf_data_map,
953 bip->bli_formats[i].blf_map_size))
954 return true;
955 }
956
957 return false;
958 }
959
960 STATIC void
xfs_buf_item_free(struct xfs_buf_log_item * bip)961 xfs_buf_item_free(
962 struct xfs_buf_log_item *bip)
963 {
964 xfs_buf_item_free_format(bip);
965 kvfree(bip->bli_item.li_lv_shadow);
966 kmem_cache_free(xfs_buf_item_cache, bip);
967 }
968
969 /*
970 * xfs_buf_item_relse() is called when the buf log item is no longer needed.
971 */
972 void
xfs_buf_item_relse(struct xfs_buf * bp)973 xfs_buf_item_relse(
974 struct xfs_buf *bp)
975 {
976 struct xfs_buf_log_item *bip = bp->b_log_item;
977
978 trace_xfs_buf_item_relse(bp, _RET_IP_);
979 ASSERT(!test_bit(XFS_LI_IN_AIL, &bip->bli_item.li_flags));
980
981 if (atomic_read(&bip->bli_refcount))
982 return;
983 bp->b_log_item = NULL;
984 xfs_buf_rele(bp);
985 xfs_buf_item_free(bip);
986 }
987
988 void
xfs_buf_item_done(struct xfs_buf * bp)989 xfs_buf_item_done(
990 struct xfs_buf *bp)
991 {
992 /*
993 * If we are forcibly shutting down, this may well be off the AIL
994 * already. That's because we simulate the log-committed callbacks to
995 * unpin these buffers. Or we may never have put this item on AIL
996 * because of the transaction was aborted forcibly.
997 * xfs_trans_ail_delete() takes care of these.
998 *
999 * Either way, AIL is useless if we're forcing a shutdown.
1000 *
1001 * Note that log recovery writes might have buffer items that are not on
1002 * the AIL even when the file system is not shut down.
1003 */
1004 xfs_trans_ail_delete(&bp->b_log_item->bli_item,
1005 (bp->b_flags & _XBF_LOGRECOVERY) ? 0 :
1006 SHUTDOWN_CORRUPT_INCORE);
1007 xfs_buf_item_relse(bp);
1008 }
1009