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xfs: add EOFBLOCKS inode tagging/untagging
[deliverable/linux.git] / fs / xfs / xfs_iomap.c
1 /*
2 * Copyright (c) 2000-2006 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_log.h"
21 #include "xfs_trans.h"
22 #include "xfs_sb.h"
23 #include "xfs_ag.h"
24 #include "xfs_alloc.h"
25 #include "xfs_quota.h"
26 #include "xfs_mount.h"
27 #include "xfs_bmap_btree.h"
28 #include "xfs_alloc_btree.h"
29 #include "xfs_ialloc_btree.h"
30 #include "xfs_dinode.h"
31 #include "xfs_inode.h"
32 #include "xfs_inode_item.h"
33 #include "xfs_btree.h"
34 #include "xfs_bmap.h"
35 #include "xfs_rtalloc.h"
36 #include "xfs_error.h"
37 #include "xfs_itable.h"
38 #include "xfs_attr.h"
39 #include "xfs_buf_item.h"
40 #include "xfs_trans_space.h"
41 #include "xfs_utils.h"
42 #include "xfs_iomap.h"
43 #include "xfs_trace.h"
44 #include "xfs_icache.h"
45
46
47 #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
48 << mp->m_writeio_log)
49 #define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP
50
51 STATIC int
52 xfs_iomap_eof_align_last_fsb(
53 xfs_mount_t *mp,
54 xfs_inode_t *ip,
55 xfs_extlen_t extsize,
56 xfs_fileoff_t *last_fsb)
57 {
58 xfs_fileoff_t new_last_fsb = 0;
59 xfs_extlen_t align = 0;
60 int eof, error;
61
62 if (!XFS_IS_REALTIME_INODE(ip)) {
63 /*
64 * Round up the allocation request to a stripe unit
65 * (m_dalign) boundary if the file size is >= stripe unit
66 * size, and we are allocating past the allocation eof.
67 *
68 * If mounted with the "-o swalloc" option the alignment is
69 * increased from the strip unit size to the stripe width.
70 */
71 if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC))
72 align = mp->m_swidth;
73 else if (mp->m_dalign)
74 align = mp->m_dalign;
75
76 if (align && XFS_ISIZE(ip) >= XFS_FSB_TO_B(mp, align))
77 new_last_fsb = roundup_64(*last_fsb, align);
78 }
79
80 /*
81 * Always round up the allocation request to an extent boundary
82 * (when file on a real-time subvolume or has di_extsize hint).
83 */
84 if (extsize) {
85 if (new_last_fsb)
86 align = roundup_64(new_last_fsb, extsize);
87 else
88 align = extsize;
89 new_last_fsb = roundup_64(*last_fsb, align);
90 }
91
92 if (new_last_fsb) {
93 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
94 if (error)
95 return error;
96 if (eof)
97 *last_fsb = new_last_fsb;
98 }
99 return 0;
100 }
101
102 STATIC int
103 xfs_alert_fsblock_zero(
104 xfs_inode_t *ip,
105 xfs_bmbt_irec_t *imap)
106 {
107 xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO,
108 "Access to block zero in inode %llu "
109 "start_block: %llx start_off: %llx "
110 "blkcnt: %llx extent-state: %x\n",
111 (unsigned long long)ip->i_ino,
112 (unsigned long long)imap->br_startblock,
113 (unsigned long long)imap->br_startoff,
114 (unsigned long long)imap->br_blockcount,
115 imap->br_state);
116 return EFSCORRUPTED;
117 }
118
119 int
120 xfs_iomap_write_direct(
121 xfs_inode_t *ip,
122 xfs_off_t offset,
123 size_t count,
124 xfs_bmbt_irec_t *imap,
125 int nmaps)
126 {
127 xfs_mount_t *mp = ip->i_mount;
128 xfs_fileoff_t offset_fsb;
129 xfs_fileoff_t last_fsb;
130 xfs_filblks_t count_fsb, resaligned;
131 xfs_fsblock_t firstfsb;
132 xfs_extlen_t extsz, temp;
133 int nimaps;
134 int bmapi_flag;
135 int quota_flag;
136 int rt;
137 xfs_trans_t *tp;
138 xfs_bmap_free_t free_list;
139 uint qblocks, resblks, resrtextents;
140 int committed;
141 int error;
142
143 error = xfs_qm_dqattach(ip, 0);
144 if (error)
145 return XFS_ERROR(error);
146
147 rt = XFS_IS_REALTIME_INODE(ip);
148 extsz = xfs_get_extsz_hint(ip);
149
150 offset_fsb = XFS_B_TO_FSBT(mp, offset);
151 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
152 if ((offset + count) > XFS_ISIZE(ip)) {
153 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
154 if (error)
155 return XFS_ERROR(error);
156 } else {
157 if (nmaps && (imap->br_startblock == HOLESTARTBLOCK))
158 last_fsb = MIN(last_fsb, (xfs_fileoff_t)
159 imap->br_blockcount +
160 imap->br_startoff);
161 }
162 count_fsb = last_fsb - offset_fsb;
163 ASSERT(count_fsb > 0);
164
165 resaligned = count_fsb;
166 if (unlikely(extsz)) {
167 if ((temp = do_mod(offset_fsb, extsz)))
168 resaligned += temp;
169 if ((temp = do_mod(resaligned, extsz)))
170 resaligned += extsz - temp;
171 }
172
173 if (unlikely(rt)) {
174 resrtextents = qblocks = resaligned;
175 resrtextents /= mp->m_sb.sb_rextsize;
176 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
177 quota_flag = XFS_QMOPT_RES_RTBLKS;
178 } else {
179 resrtextents = 0;
180 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
181 quota_flag = XFS_QMOPT_RES_REGBLKS;
182 }
183
184 /*
185 * Allocate and setup the transaction
186 */
187 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
188 error = xfs_trans_reserve(tp, resblks,
189 XFS_WRITE_LOG_RES(mp), resrtextents,
190 XFS_TRANS_PERM_LOG_RES,
191 XFS_WRITE_LOG_COUNT);
192 /*
193 * Check for running out of space, note: need lock to return
194 */
195 if (error) {
196 xfs_trans_cancel(tp, 0);
197 return XFS_ERROR(error);
198 }
199
200 xfs_ilock(ip, XFS_ILOCK_EXCL);
201
202 error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
203 if (error)
204 goto out_trans_cancel;
205
206 xfs_trans_ijoin(tp, ip, 0);
207
208 bmapi_flag = 0;
209 if (offset < XFS_ISIZE(ip) || extsz)
210 bmapi_flag |= XFS_BMAPI_PREALLOC;
211
212 /*
213 * From this point onwards we overwrite the imap pointer that the
214 * caller gave to us.
215 */
216 xfs_bmap_init(&free_list, &firstfsb);
217 nimaps = 1;
218 error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, bmapi_flag,
219 &firstfsb, 0, imap, &nimaps, &free_list);
220 if (error)
221 goto out_bmap_cancel;
222
223 /*
224 * Complete the transaction
225 */
226 error = xfs_bmap_finish(&tp, &free_list, &committed);
227 if (error)
228 goto out_bmap_cancel;
229 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
230 if (error)
231 goto out_unlock;
232
233 /*
234 * Copy any maps to caller's array and return any error.
235 */
236 if (nimaps == 0) {
237 error = XFS_ERROR(ENOSPC);
238 goto out_unlock;
239 }
240
241 if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip)))
242 error = xfs_alert_fsblock_zero(ip, imap);
243
244 out_unlock:
245 xfs_iunlock(ip, XFS_ILOCK_EXCL);
246 return error;
247
248 out_bmap_cancel:
249 xfs_bmap_cancel(&free_list);
250 xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag);
251 out_trans_cancel:
252 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
253 goto out_unlock;
254 }
255
256 /*
257 * If the caller is doing a write at the end of the file, then extend the
258 * allocation out to the file system's write iosize. We clean up any extra
259 * space left over when the file is closed in xfs_inactive().
260 *
261 * If we find we already have delalloc preallocation beyond EOF, don't do more
262 * preallocation as it it not needed.
263 */
264 STATIC int
265 xfs_iomap_eof_want_preallocate(
266 xfs_mount_t *mp,
267 xfs_inode_t *ip,
268 xfs_off_t offset,
269 size_t count,
270 xfs_bmbt_irec_t *imap,
271 int nimaps,
272 int *prealloc)
273 {
274 xfs_fileoff_t start_fsb;
275 xfs_filblks_t count_fsb;
276 xfs_fsblock_t firstblock;
277 int n, error, imaps;
278 int found_delalloc = 0;
279
280 *prealloc = 0;
281 if (offset + count <= XFS_ISIZE(ip))
282 return 0;
283
284 /*
285 * If there are any real blocks past eof, then don't
286 * do any speculative allocation.
287 */
288 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
289 count_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
290 while (count_fsb > 0) {
291 imaps = nimaps;
292 firstblock = NULLFSBLOCK;
293 error = xfs_bmapi_read(ip, start_fsb, count_fsb, imap, &imaps,
294 0);
295 if (error)
296 return error;
297 for (n = 0; n < imaps; n++) {
298 if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
299 (imap[n].br_startblock != DELAYSTARTBLOCK))
300 return 0;
301 start_fsb += imap[n].br_blockcount;
302 count_fsb -= imap[n].br_blockcount;
303
304 if (imap[n].br_startblock == DELAYSTARTBLOCK)
305 found_delalloc = 1;
306 }
307 }
308 if (!found_delalloc)
309 *prealloc = 1;
310 return 0;
311 }
312
313 /*
314 * If we don't have a user specified preallocation size, dynamically increase
315 * the preallocation size as the size of the file grows. Cap the maximum size
316 * at a single extent or less if the filesystem is near full. The closer the
317 * filesystem is to full, the smaller the maximum prealocation.
318 */
319 STATIC xfs_fsblock_t
320 xfs_iomap_prealloc_size(
321 struct xfs_mount *mp,
322 struct xfs_inode *ip)
323 {
324 xfs_fsblock_t alloc_blocks = 0;
325
326 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
327 int shift = 0;
328 int64_t freesp;
329
330 /*
331 * rounddown_pow_of_two() returns an undefined result
332 * if we pass in alloc_blocks = 0. Hence the "+ 1" to
333 * ensure we always pass in a non-zero value.
334 */
335 alloc_blocks = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)) + 1;
336 alloc_blocks = XFS_FILEOFF_MIN(MAXEXTLEN,
337 rounddown_pow_of_two(alloc_blocks));
338
339 xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);
340 freesp = mp->m_sb.sb_fdblocks;
341 if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) {
342 shift = 2;
343 if (freesp < mp->m_low_space[XFS_LOWSP_4_PCNT])
344 shift++;
345 if (freesp < mp->m_low_space[XFS_LOWSP_3_PCNT])
346 shift++;
347 if (freesp < mp->m_low_space[XFS_LOWSP_2_PCNT])
348 shift++;
349 if (freesp < mp->m_low_space[XFS_LOWSP_1_PCNT])
350 shift++;
351 }
352 if (shift)
353 alloc_blocks >>= shift;
354 }
355
356 if (alloc_blocks < mp->m_writeio_blocks)
357 alloc_blocks = mp->m_writeio_blocks;
358
359 return alloc_blocks;
360 }
361
362 int
363 xfs_iomap_write_delay(
364 xfs_inode_t *ip,
365 xfs_off_t offset,
366 size_t count,
367 xfs_bmbt_irec_t *ret_imap)
368 {
369 xfs_mount_t *mp = ip->i_mount;
370 xfs_fileoff_t offset_fsb;
371 xfs_fileoff_t last_fsb;
372 xfs_off_t aligned_offset;
373 xfs_fileoff_t ioalign;
374 xfs_extlen_t extsz;
375 int nimaps;
376 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
377 int prealloc;
378 int error;
379
380 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
381
382 /*
383 * Make sure that the dquots are there. This doesn't hold
384 * the ilock across a disk read.
385 */
386 error = xfs_qm_dqattach_locked(ip, 0);
387 if (error)
388 return XFS_ERROR(error);
389
390 extsz = xfs_get_extsz_hint(ip);
391 offset_fsb = XFS_B_TO_FSBT(mp, offset);
392
393
394 error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count,
395 imap, XFS_WRITE_IMAPS, &prealloc);
396 if (error)
397 return error;
398
399 retry:
400 if (prealloc) {
401 xfs_fsblock_t alloc_blocks = xfs_iomap_prealloc_size(mp, ip);
402
403 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
404 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
405 last_fsb = ioalign + alloc_blocks;
406 } else {
407 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
408 }
409
410 if (prealloc || extsz) {
411 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
412 if (error)
413 return error;
414 }
415
416 /*
417 * Make sure preallocation does not create extents beyond the range we
418 * actually support in this filesystem.
419 */
420 if (last_fsb > XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes))
421 last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
422
423 ASSERT(last_fsb > offset_fsb);
424
425 nimaps = XFS_WRITE_IMAPS;
426 error = xfs_bmapi_delay(ip, offset_fsb, last_fsb - offset_fsb,
427 imap, &nimaps, XFS_BMAPI_ENTIRE);
428 switch (error) {
429 case 0:
430 case ENOSPC:
431 case EDQUOT:
432 break;
433 default:
434 return XFS_ERROR(error);
435 }
436
437 /*
438 * If bmapi returned us nothing, we got either ENOSPC or EDQUOT. Retry
439 * without EOF preallocation.
440 */
441 if (nimaps == 0) {
442 trace_xfs_delalloc_enospc(ip, offset, count);
443 if (prealloc) {
444 prealloc = 0;
445 error = 0;
446 goto retry;
447 }
448 return XFS_ERROR(error ? error : ENOSPC);
449 }
450
451 if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip)))
452 return xfs_alert_fsblock_zero(ip, &imap[0]);
453
454 /*
455 * Tag the inode as speculatively preallocated so we can reclaim this
456 * space on demand, if necessary.
457 */
458 if (prealloc)
459 xfs_inode_set_eofblocks_tag(ip);
460
461 *ret_imap = imap[0];
462 return 0;
463 }
464
465 /*
466 * Pass in a delayed allocate extent, convert it to real extents;
467 * return to the caller the extent we create which maps on top of
468 * the originating callers request.
469 *
470 * Called without a lock on the inode.
471 *
472 * We no longer bother to look at the incoming map - all we have to
473 * guarantee is that whatever we allocate fills the required range.
474 */
475 int
476 xfs_iomap_write_allocate(
477 xfs_inode_t *ip,
478 xfs_off_t offset,
479 size_t count,
480 xfs_bmbt_irec_t *imap)
481 {
482 xfs_mount_t *mp = ip->i_mount;
483 xfs_fileoff_t offset_fsb, last_block;
484 xfs_fileoff_t end_fsb, map_start_fsb;
485 xfs_fsblock_t first_block;
486 xfs_bmap_free_t free_list;
487 xfs_filblks_t count_fsb;
488 xfs_trans_t *tp;
489 int nimaps, committed;
490 int error = 0;
491 int nres;
492
493 /*
494 * Make sure that the dquots are there.
495 */
496 error = xfs_qm_dqattach(ip, 0);
497 if (error)
498 return XFS_ERROR(error);
499
500 offset_fsb = XFS_B_TO_FSBT(mp, offset);
501 count_fsb = imap->br_blockcount;
502 map_start_fsb = imap->br_startoff;
503
504 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
505
506 while (count_fsb != 0) {
507 /*
508 * Set up a transaction with which to allocate the
509 * backing store for the file. Do allocations in a
510 * loop until we get some space in the range we are
511 * interested in. The other space that might be allocated
512 * is in the delayed allocation extent on which we sit
513 * but before our buffer starts.
514 */
515
516 nimaps = 0;
517 while (nimaps == 0) {
518 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
519 tp->t_flags |= XFS_TRANS_RESERVE;
520 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
521 error = xfs_trans_reserve(tp, nres,
522 XFS_WRITE_LOG_RES(mp),
523 0, XFS_TRANS_PERM_LOG_RES,
524 XFS_WRITE_LOG_COUNT);
525 if (error) {
526 xfs_trans_cancel(tp, 0);
527 return XFS_ERROR(error);
528 }
529 xfs_ilock(ip, XFS_ILOCK_EXCL);
530 xfs_trans_ijoin(tp, ip, 0);
531
532 xfs_bmap_init(&free_list, &first_block);
533
534 /*
535 * it is possible that the extents have changed since
536 * we did the read call as we dropped the ilock for a
537 * while. We have to be careful about truncates or hole
538 * punchs here - we are not allowed to allocate
539 * non-delalloc blocks here.
540 *
541 * The only protection against truncation is the pages
542 * for the range we are being asked to convert are
543 * locked and hence a truncate will block on them
544 * first.
545 *
546 * As a result, if we go beyond the range we really
547 * need and hit an delalloc extent boundary followed by
548 * a hole while we have excess blocks in the map, we
549 * will fill the hole incorrectly and overrun the
550 * transaction reservation.
551 *
552 * Using a single map prevents this as we are forced to
553 * check each map we look for overlap with the desired
554 * range and abort as soon as we find it. Also, given
555 * that we only return a single map, having one beyond
556 * what we can return is probably a bit silly.
557 *
558 * We also need to check that we don't go beyond EOF;
559 * this is a truncate optimisation as a truncate sets
560 * the new file size before block on the pages we
561 * currently have locked under writeback. Because they
562 * are about to be tossed, we don't need to write them
563 * back....
564 */
565 nimaps = 1;
566 end_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
567 error = xfs_bmap_last_offset(NULL, ip, &last_block,
568 XFS_DATA_FORK);
569 if (error)
570 goto trans_cancel;
571
572 last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
573 if ((map_start_fsb + count_fsb) > last_block) {
574 count_fsb = last_block - map_start_fsb;
575 if (count_fsb == 0) {
576 error = EAGAIN;
577 goto trans_cancel;
578 }
579 }
580
581 /*
582 * From this point onwards we overwrite the imap
583 * pointer that the caller gave to us.
584 */
585 error = xfs_bmapi_write(tp, ip, map_start_fsb,
586 count_fsb,
587 XFS_BMAPI_STACK_SWITCH,
588 &first_block, 1,
589 imap, &nimaps, &free_list);
590 if (error)
591 goto trans_cancel;
592
593 error = xfs_bmap_finish(&tp, &free_list, &committed);
594 if (error)
595 goto trans_cancel;
596
597 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
598 if (error)
599 goto error0;
600
601 xfs_iunlock(ip, XFS_ILOCK_EXCL);
602 }
603
604 /*
605 * See if we were able to allocate an extent that
606 * covers at least part of the callers request
607 */
608 if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip)))
609 return xfs_alert_fsblock_zero(ip, imap);
610
611 if ((offset_fsb >= imap->br_startoff) &&
612 (offset_fsb < (imap->br_startoff +
613 imap->br_blockcount))) {
614 XFS_STATS_INC(xs_xstrat_quick);
615 return 0;
616 }
617
618 /*
619 * So far we have not mapped the requested part of the
620 * file, just surrounding data, try again.
621 */
622 count_fsb -= imap->br_blockcount;
623 map_start_fsb = imap->br_startoff + imap->br_blockcount;
624 }
625
626 trans_cancel:
627 xfs_bmap_cancel(&free_list);
628 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
629 error0:
630 xfs_iunlock(ip, XFS_ILOCK_EXCL);
631 return XFS_ERROR(error);
632 }
633
634 int
635 xfs_iomap_write_unwritten(
636 xfs_inode_t *ip,
637 xfs_off_t offset,
638 size_t count)
639 {
640 xfs_mount_t *mp = ip->i_mount;
641 xfs_fileoff_t offset_fsb;
642 xfs_filblks_t count_fsb;
643 xfs_filblks_t numblks_fsb;
644 xfs_fsblock_t firstfsb;
645 int nimaps;
646 xfs_trans_t *tp;
647 xfs_bmbt_irec_t imap;
648 xfs_bmap_free_t free_list;
649 xfs_fsize_t i_size;
650 uint resblks;
651 int committed;
652 int error;
653
654 trace_xfs_unwritten_convert(ip, offset, count);
655
656 offset_fsb = XFS_B_TO_FSBT(mp, offset);
657 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
658 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
659
660 /*
661 * Reserve enough blocks in this transaction for two complete extent
662 * btree splits. We may be converting the middle part of an unwritten
663 * extent and in this case we will insert two new extents in the btree
664 * each of which could cause a full split.
665 *
666 * This reservation amount will be used in the first call to
667 * xfs_bmbt_split() to select an AG with enough space to satisfy the
668 * rest of the operation.
669 */
670 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
671
672 do {
673 /*
674 * set up a transaction to convert the range of extents
675 * from unwritten to real. Do allocations in a loop until
676 * we have covered the range passed in.
677 *
678 * Note that we open code the transaction allocation here
679 * to pass KM_NOFS--we can't risk to recursing back into
680 * the filesystem here as we might be asked to write out
681 * the same inode that we complete here and might deadlock
682 * on the iolock.
683 */
684 sb_start_intwrite(mp->m_super);
685 tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS);
686 tp->t_flags |= XFS_TRANS_RESERVE | XFS_TRANS_FREEZE_PROT;
687 error = xfs_trans_reserve(tp, resblks,
688 XFS_WRITE_LOG_RES(mp), 0,
689 XFS_TRANS_PERM_LOG_RES,
690 XFS_WRITE_LOG_COUNT);
691 if (error) {
692 xfs_trans_cancel(tp, 0);
693 return XFS_ERROR(error);
694 }
695
696 xfs_ilock(ip, XFS_ILOCK_EXCL);
697 xfs_trans_ijoin(tp, ip, 0);
698
699 /*
700 * Modify the unwritten extent state of the buffer.
701 */
702 xfs_bmap_init(&free_list, &firstfsb);
703 nimaps = 1;
704 error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb,
705 XFS_BMAPI_CONVERT, &firstfsb,
706 1, &imap, &nimaps, &free_list);
707 if (error)
708 goto error_on_bmapi_transaction;
709
710 /*
711 * Log the updated inode size as we go. We have to be careful
712 * to only log it up to the actual write offset if it is
713 * halfway into a block.
714 */
715 i_size = XFS_FSB_TO_B(mp, offset_fsb + count_fsb);
716 if (i_size > offset + count)
717 i_size = offset + count;
718
719 i_size = xfs_new_eof(ip, i_size);
720 if (i_size) {
721 ip->i_d.di_size = i_size;
722 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
723 }
724
725 error = xfs_bmap_finish(&tp, &free_list, &committed);
726 if (error)
727 goto error_on_bmapi_transaction;
728
729 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
730 xfs_iunlock(ip, XFS_ILOCK_EXCL);
731 if (error)
732 return XFS_ERROR(error);
733
734 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
735 return xfs_alert_fsblock_zero(ip, &imap);
736
737 if ((numblks_fsb = imap.br_blockcount) == 0) {
738 /*
739 * The numblks_fsb value should always get
740 * smaller, otherwise the loop is stuck.
741 */
742 ASSERT(imap.br_blockcount);
743 break;
744 }
745 offset_fsb += numblks_fsb;
746 count_fsb -= numblks_fsb;
747 } while (count_fsb > 0);
748
749 return 0;
750
751 error_on_bmapi_transaction:
752 xfs_bmap_cancel(&free_list);
753 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
754 xfs_iunlock(ip, XFS_ILOCK_EXCL);
755 return XFS_ERROR(error);
756 }
Linux kernel - Deliverables
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