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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
45
46#define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
47 << mp->m_writeio_log)
48#define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP
49
50STATIC int
51xfs_iomap_eof_align_last_fsb(
52 xfs_mount_t *mp,
53 xfs_inode_t *ip,
54 xfs_extlen_t extsize,
55 xfs_fileoff_t *last_fsb)
56{
57 xfs_fileoff_t new_last_fsb = 0;
58 xfs_extlen_t align = 0;
59 int eof, error;
60
61 if (!XFS_IS_REALTIME_INODE(ip)) {
62 /*
63 * Round up the allocation request to a stripe unit
64 * (m_dalign) boundary if the file size is >= stripe unit
65 * size, and we are allocating past the allocation eof.
66 *
67 * If mounted with the "-o swalloc" option the alignment is
68 * increased from the strip unit size to the stripe width.
69 */
70 if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC))
71 align = mp->m_swidth;
72 else if (mp->m_dalign)
73 align = mp->m_dalign;
74
75 if (align && XFS_ISIZE(ip) >= XFS_FSB_TO_B(mp, align))
76 new_last_fsb = roundup_64(*last_fsb, align);
77 }
78
79 /*
80 * Always round up the allocation request to an extent boundary
81 * (when file on a real-time subvolume or has di_extsize hint).
82 */
83 if (extsize) {
84 if (new_last_fsb)
85 align = roundup_64(new_last_fsb, extsize);
86 else
87 align = extsize;
88 new_last_fsb = roundup_64(*last_fsb, align);
89 }
90
91 if (new_last_fsb) {
92 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
93 if (error)
94 return error;
95 if (eof)
96 *last_fsb = new_last_fsb;
97 }
98 return 0;
99}
100
101STATIC int
102xfs_alert_fsblock_zero(
103 xfs_inode_t *ip,
104 xfs_bmbt_irec_t *imap)
105{
106 xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO,
107 "Access to block zero in inode %llu "
108 "start_block: %llx start_off: %llx "
109 "blkcnt: %llx extent-state: %x\n",
110 (unsigned long long)ip->i_ino,
111 (unsigned long long)imap->br_startblock,
112 (unsigned long long)imap->br_startoff,
113 (unsigned long long)imap->br_blockcount,
114 imap->br_state);
115 return EFSCORRUPTED;
116}
117
118int
119xfs_iomap_write_direct(
120 xfs_inode_t *ip,
121 xfs_off_t offset,
122 size_t count,
123 xfs_bmbt_irec_t *imap,
124 int nmaps)
125{
126 xfs_mount_t *mp = ip->i_mount;
127 xfs_fileoff_t offset_fsb;
128 xfs_fileoff_t last_fsb;
129 xfs_filblks_t count_fsb, resaligned;
130 xfs_fsblock_t firstfsb;
131 xfs_extlen_t extsz, temp;
132 int nimaps;
133 int bmapi_flag;
134 int quota_flag;
135 int rt;
136 xfs_trans_t *tp;
137 xfs_bmap_free_t free_list;
138 uint qblocks, resblks, resrtextents;
139 int committed;
140 int error;
141
142 error = xfs_qm_dqattach(ip, 0);
143 if (error)
144 return XFS_ERROR(error);
145
146 rt = XFS_IS_REALTIME_INODE(ip);
147 extsz = xfs_get_extsz_hint(ip);
148
149 offset_fsb = XFS_B_TO_FSBT(mp, offset);
150 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
151 if ((offset + count) > XFS_ISIZE(ip)) {
152 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
153 if (error)
154 return XFS_ERROR(error);
155 } else {
156 if (nmaps && (imap->br_startblock == HOLESTARTBLOCK))
157 last_fsb = MIN(last_fsb, (xfs_fileoff_t)
158 imap->br_blockcount +
159 imap->br_startoff);
160 }
161 count_fsb = last_fsb - offset_fsb;
162 ASSERT(count_fsb > 0);
163
164 resaligned = count_fsb;
165 if (unlikely(extsz)) {
166 if ((temp = do_mod(offset_fsb, extsz)))
167 resaligned += temp;
168 if ((temp = do_mod(resaligned, extsz)))
169 resaligned += extsz - temp;
170 }
171
172 if (unlikely(rt)) {
173 resrtextents = qblocks = resaligned;
174 resrtextents /= mp->m_sb.sb_rextsize;
175 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
176 quota_flag = XFS_QMOPT_RES_RTBLKS;
177 } else {
178 resrtextents = 0;
179 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
180 quota_flag = XFS_QMOPT_RES_REGBLKS;
181 }
182
183 /*
184 * Allocate and setup the transaction
185 */
186 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
187 error = xfs_trans_reserve(tp, resblks,
188 XFS_WRITE_LOG_RES(mp), resrtextents,
189 XFS_TRANS_PERM_LOG_RES,
190 XFS_WRITE_LOG_COUNT);
191 /*
192 * Check for running out of space, note: need lock to return
193 */
194 if (error) {
195 xfs_trans_cancel(tp, 0);
196 return XFS_ERROR(error);
197 }
198
199 xfs_ilock(ip, XFS_ILOCK_EXCL);
200
201 error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
202 if (error)
203 goto out_trans_cancel;
204
205 xfs_trans_ijoin(tp, ip, 0);
206
207 bmapi_flag = 0;
208 if (offset < XFS_ISIZE(ip) || extsz)
209 bmapi_flag |= XFS_BMAPI_PREALLOC;
210
211 /*
212 * From this point onwards we overwrite the imap pointer that the
213 * caller gave to us.
214 */
215 xfs_bmap_init(&free_list, &firstfsb);
216 nimaps = 1;
217 error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, bmapi_flag,
218 &firstfsb, 0, imap, &nimaps, &free_list);
219 if (error)
220 goto out_bmap_cancel;
221
222 /*
223 * Complete the transaction
224 */
225 error = xfs_bmap_finish(&tp, &free_list, &committed);
226 if (error)
227 goto out_bmap_cancel;
228 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
229 if (error)
230 goto out_unlock;
231
232 /*
233 * Copy any maps to caller's array and return any error.
234 */
235 if (nimaps == 0) {
236 error = XFS_ERROR(ENOSPC);
237 goto out_unlock;
238 }
239
240 if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip)))
241 error = xfs_alert_fsblock_zero(ip, imap);
242
243out_unlock:
244 xfs_iunlock(ip, XFS_ILOCK_EXCL);
245 return error;
246
247out_bmap_cancel:
248 xfs_bmap_cancel(&free_list);
249 xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag);
250out_trans_cancel:
251 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
252 goto out_unlock;
253}
254
255/*
256 * If the caller is doing a write at the end of the file, then extend the
257 * allocation out to the file system's write iosize. We clean up any extra
258 * space left over when the file is closed in xfs_inactive().
259 *
260 * If we find we already have delalloc preallocation beyond EOF, don't do more
261 * preallocation as it it not needed.
262 */
263STATIC int
264xfs_iomap_eof_want_preallocate(
265 xfs_mount_t *mp,
266 xfs_inode_t *ip,
267 xfs_off_t offset,
268 size_t count,
269 xfs_bmbt_irec_t *imap,
270 int nimaps,
271 int *prealloc)
272{
273 xfs_fileoff_t start_fsb;
274 xfs_filblks_t count_fsb;
275 xfs_fsblock_t firstblock;
276 int n, error, imaps;
277 int found_delalloc = 0;
278
279 *prealloc = 0;
280 if (offset + count <= XFS_ISIZE(ip))
281 return 0;
282
283 /*
284 * If there are any real blocks past eof, then don't
285 * do any speculative allocation.
286 */
287 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
288 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
289 while (count_fsb > 0) {
290 imaps = nimaps;
291 firstblock = NULLFSBLOCK;
292 error = xfs_bmapi_read(ip, start_fsb, count_fsb, imap, &imaps,
293 0);
294 if (error)
295 return error;
296 for (n = 0; n < imaps; n++) {
297 if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
298 (imap[n].br_startblock != DELAYSTARTBLOCK))
299 return 0;
300 start_fsb += imap[n].br_blockcount;
301 count_fsb -= imap[n].br_blockcount;
302
303 if (imap[n].br_startblock == DELAYSTARTBLOCK)
304 found_delalloc = 1;
305 }
306 }
307 if (!found_delalloc)
308 *prealloc = 1;
309 return 0;
310}
311
312/*
313 * If we don't have a user specified preallocation size, dynamically increase
314 * the preallocation size as the size of the file grows. Cap the maximum size
315 * at a single extent or less if the filesystem is near full. The closer the
316 * filesystem is to full, the smaller the maximum prealocation.
317 */
318STATIC xfs_fsblock_t
319xfs_iomap_prealloc_size(
320 struct xfs_mount *mp,
321 struct xfs_inode *ip)
322{
323 xfs_fsblock_t alloc_blocks = 0;
324
325 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
326 int shift = 0;
327 int64_t freesp;
328
329 /*
330 * rounddown_pow_of_two() returns an undefined result
331 * if we pass in alloc_blocks = 0. Hence the "+ 1" to
332 * ensure we always pass in a non-zero value.
333 */
334 alloc_blocks = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)) + 1;
335 alloc_blocks = XFS_FILEOFF_MIN(MAXEXTLEN,
336 rounddown_pow_of_two(alloc_blocks));
337
338 xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);
339 freesp = mp->m_sb.sb_fdblocks;
340 if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) {
341 shift = 2;
342 if (freesp < mp->m_low_space[XFS_LOWSP_4_PCNT])
343 shift++;
344 if (freesp < mp->m_low_space[XFS_LOWSP_3_PCNT])
345 shift++;
346 if (freesp < mp->m_low_space[XFS_LOWSP_2_PCNT])
347 shift++;
348 if (freesp < mp->m_low_space[XFS_LOWSP_1_PCNT])
349 shift++;
350 }
351 if (shift)
352 alloc_blocks >>= shift;
353 }
354
355 if (alloc_blocks < mp->m_writeio_blocks)
356 alloc_blocks = mp->m_writeio_blocks;
357
358 return alloc_blocks;
359}
360
361int
362xfs_iomap_write_delay(
363 xfs_inode_t *ip,
364 xfs_off_t offset,
365 size_t count,
366 xfs_bmbt_irec_t *ret_imap)
367{
368 xfs_mount_t *mp = ip->i_mount;
369 xfs_fileoff_t offset_fsb;
370 xfs_fileoff_t last_fsb;
371 xfs_off_t aligned_offset;
372 xfs_fileoff_t ioalign;
373 xfs_extlen_t extsz;
374 int nimaps;
375 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
376 int prealloc, flushed = 0;
377 int error;
378
379 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
380
381 /*
382 * Make sure that the dquots are there. This doesn't hold
383 * the ilock across a disk read.
384 */
385 error = xfs_qm_dqattach_locked(ip, 0);
386 if (error)
387 return XFS_ERROR(error);
388
389 extsz = xfs_get_extsz_hint(ip);
390 offset_fsb = XFS_B_TO_FSBT(mp, offset);
391
392
393 error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count,
394 imap, XFS_WRITE_IMAPS, &prealloc);
395 if (error)
396 return error;
397
398retry:
399 if (prealloc) {
400 xfs_fsblock_t alloc_blocks = xfs_iomap_prealloc_size(mp, ip);
401
402 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
403 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
404 last_fsb = ioalign + alloc_blocks;
405 } else {
406 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
407 }
408
409 if (prealloc || extsz) {
410 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
411 if (error)
412 return error;
413 }
414
415 /*
416 * Make sure preallocation does not create extents beyond the range we
417 * actually support in this filesystem.
418 */
419 if (last_fsb > XFS_B_TO_FSB(mp, mp->m_maxioffset))
420 last_fsb = XFS_B_TO_FSB(mp, mp->m_maxioffset);
421
422 ASSERT(last_fsb > offset_fsb);
423
424 nimaps = XFS_WRITE_IMAPS;
425 error = xfs_bmapi_delay(ip, offset_fsb, last_fsb - offset_fsb,
426 imap, &nimaps, XFS_BMAPI_ENTIRE);
427 switch (error) {
428 case 0:
429 case ENOSPC:
430 case EDQUOT:
431 break;
432 default:
433 return XFS_ERROR(error);
434 }
435
436 /*
437 * If bmapi returned us nothing, we got either ENOSPC or EDQUOT. For
438 * ENOSPC, * flush all other inodes with delalloc blocks to free up
439 * some of the excess reserved metadata space. For both cases, retry
440 * without EOF preallocation.
441 */
442 if (nimaps == 0) {
443 trace_xfs_delalloc_enospc(ip, offset, count);
444 if (flushed)
445 return XFS_ERROR(error ? error : ENOSPC);
446
447 if (error == ENOSPC) {
448 xfs_iunlock(ip, XFS_ILOCK_EXCL);
449 xfs_flush_inodes(ip);
450 xfs_ilock(ip, XFS_ILOCK_EXCL);
451 }
452
453 flushed = 1;
454 error = 0;
455 prealloc = 0;
456 goto retry;
457 }
458
459 if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip)))
460 return xfs_alert_fsblock_zero(ip, &imap[0]);
461
462 *ret_imap = imap[0];
463 return 0;
464}
465
466/*
467 * Pass in a delayed allocate extent, convert it to real extents;
468 * return to the caller the extent we create which maps on top of
469 * the originating callers request.
470 *
471 * Called without a lock on the inode.
472 *
473 * We no longer bother to look at the incoming map - all we have to
474 * guarantee is that whatever we allocate fills the required range.
475 */
476int
477xfs_iomap_write_allocate(
478 xfs_inode_t *ip,
479 xfs_off_t offset,
480 size_t count,
481 xfs_bmbt_irec_t *imap)
482{
483 xfs_mount_t *mp = ip->i_mount;
484 xfs_fileoff_t offset_fsb, last_block;
485 xfs_fileoff_t end_fsb, map_start_fsb;
486 xfs_fsblock_t first_block;
487 xfs_bmap_free_t free_list;
488 xfs_filblks_t count_fsb;
489 xfs_trans_t *tp;
490 int nimaps, committed;
491 int error = 0;
492 int nres;
493
494 /*
495 * Make sure that the dquots are there.
496 */
497 error = xfs_qm_dqattach(ip, 0);
498 if (error)
499 return XFS_ERROR(error);
500
501 offset_fsb = XFS_B_TO_FSBT(mp, offset);
502 count_fsb = imap->br_blockcount;
503 map_start_fsb = imap->br_startoff;
504
505 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
506
507 while (count_fsb != 0) {
508 /*
509 * Set up a transaction with which to allocate the
510 * backing store for the file. Do allocations in a
511 * loop until we get some space in the range we are
512 * interested in. The other space that might be allocated
513 * is in the delayed allocation extent on which we sit
514 * but before our buffer starts.
515 */
516
517 nimaps = 0;
518 while (nimaps == 0) {
519 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
520 tp->t_flags |= XFS_TRANS_RESERVE;
521 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
522 error = xfs_trans_reserve(tp, nres,
523 XFS_WRITE_LOG_RES(mp),
524 0, XFS_TRANS_PERM_LOG_RES,
525 XFS_WRITE_LOG_COUNT);
526 if (error) {
527 xfs_trans_cancel(tp, 0);
528 return XFS_ERROR(error);
529 }
530 xfs_ilock(ip, XFS_ILOCK_EXCL);
531 xfs_trans_ijoin(tp, ip, 0);
532
533 xfs_bmap_init(&free_list, &first_block);
534
535 /*
536 * it is possible that the extents have changed since
537 * we did the read call as we dropped the ilock for a
538 * while. We have to be careful about truncates or hole
539 * punchs here - we are not allowed to allocate
540 * non-delalloc blocks here.
541 *
542 * The only protection against truncation is the pages
543 * for the range we are being asked to convert are
544 * locked and hence a truncate will block on them
545 * first.
546 *
547 * As a result, if we go beyond the range we really
548 * need and hit an delalloc extent boundary followed by
549 * a hole while we have excess blocks in the map, we
550 * will fill the hole incorrectly and overrun the
551 * transaction reservation.
552 *
553 * Using a single map prevents this as we are forced to
554 * check each map we look for overlap with the desired
555 * range and abort as soon as we find it. Also, given
556 * that we only return a single map, having one beyond
557 * what we can return is probably a bit silly.
558 *
559 * We also need to check that we don't go beyond EOF;
560 * this is a truncate optimisation as a truncate sets
561 * the new file size before block on the pages we
562 * currently have locked under writeback. Because they
563 * are about to be tossed, we don't need to write them
564 * back....
565 */
566 nimaps = 1;
567 end_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
568 error = xfs_bmap_last_offset(NULL, ip, &last_block,
569 XFS_DATA_FORK);
570 if (error)
571 goto trans_cancel;
572
573 last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
574 if ((map_start_fsb + count_fsb) > last_block) {
575 count_fsb = last_block - map_start_fsb;
576 if (count_fsb == 0) {
577 error = EAGAIN;
578 goto trans_cancel;
579 }
580 }
581
582 /*
583 * From this point onwards we overwrite the imap
584 * pointer that the caller gave to us.
585 */
586 error = xfs_bmapi_write(tp, ip, map_start_fsb,
587 count_fsb, 0, &first_block, 1,
588 imap, &nimaps, &free_list);
589 if (error)
590 goto trans_cancel;
591
592 error = xfs_bmap_finish(&tp, &free_list, &committed);
593 if (error)
594 goto trans_cancel;
595
596 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
597 if (error)
598 goto error0;
599
600 xfs_iunlock(ip, XFS_ILOCK_EXCL);
601 }
602
603 /*
604 * See if we were able to allocate an extent that
605 * covers at least part of the callers request
606 */
607 if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip)))
608 return xfs_alert_fsblock_zero(ip, imap);
609
610 if ((offset_fsb >= imap->br_startoff) &&
611 (offset_fsb < (imap->br_startoff +
612 imap->br_blockcount))) {
613 XFS_STATS_INC(xs_xstrat_quick);
614 return 0;
615 }
616
617 /*
618 * So far we have not mapped the requested part of the
619 * file, just surrounding data, try again.
620 */
621 count_fsb -= imap->br_blockcount;
622 map_start_fsb = imap->br_startoff + imap->br_blockcount;
623 }
624
625trans_cancel:
626 xfs_bmap_cancel(&free_list);
627 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
628error0:
629 xfs_iunlock(ip, XFS_ILOCK_EXCL);
630 return XFS_ERROR(error);
631}
632
633int
634xfs_iomap_write_unwritten(
635 xfs_inode_t *ip,
636 xfs_off_t offset,
637 size_t count)
638{
639 xfs_mount_t *mp = ip->i_mount;
640 xfs_fileoff_t offset_fsb;
641 xfs_filblks_t count_fsb;
642 xfs_filblks_t numblks_fsb;
643 xfs_fsblock_t firstfsb;
644 int nimaps;
645 xfs_trans_t *tp;
646 xfs_bmbt_irec_t imap;
647 xfs_bmap_free_t free_list;
648 xfs_fsize_t i_size;
649 uint resblks;
650 int committed;
651 int error;
652
653 trace_xfs_unwritten_convert(ip, offset, count);
654
655 offset_fsb = XFS_B_TO_FSBT(mp, offset);
656 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
657 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
658
659 /*
660 * Reserve enough blocks in this transaction for two complete extent
661 * btree splits. We may be converting the middle part of an unwritten
662 * extent and in this case we will insert two new extents in the btree
663 * each of which could cause a full split.
664 *
665 * This reservation amount will be used in the first call to
666 * xfs_bmbt_split() to select an AG with enough space to satisfy the
667 * rest of the operation.
668 */
669 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
670
671 do {
672 /*
673 * set up a transaction to convert the range of extents
674 * from unwritten to real. Do allocations in a loop until
675 * we have covered the range passed in.
676 *
677 * Note that we open code the transaction allocation here
678 * to pass KM_NOFS--we can't risk to recursing back into
679 * the filesystem here as we might be asked to write out
680 * the same inode that we complete here and might deadlock
681 * on the iolock.
682 */
683 xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
684 tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS);
685 tp->t_flags |= XFS_TRANS_RESERVE;
686 error = xfs_trans_reserve(tp, resblks,
687 XFS_WRITE_LOG_RES(mp), 0,
688 XFS_TRANS_PERM_LOG_RES,
689 XFS_WRITE_LOG_COUNT);
690 if (error) {
691 xfs_trans_cancel(tp, 0);
692 return XFS_ERROR(error);
693 }
694
695 xfs_ilock(ip, XFS_ILOCK_EXCL);
696 xfs_trans_ijoin(tp, ip, 0);
697
698 /*
699 * Modify the unwritten extent state of the buffer.
700 */
701 xfs_bmap_init(&free_list, &firstfsb);
702 nimaps = 1;
703 error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb,
704 XFS_BMAPI_CONVERT, &firstfsb,
705 1, &imap, &nimaps, &free_list);
706 if (error)
707 goto error_on_bmapi_transaction;
708
709 /*
710 * Log the updated inode size as we go. We have to be careful
711 * to only log it up to the actual write offset if it is
712 * halfway into a block.
713 */
714 i_size = XFS_FSB_TO_B(mp, offset_fsb + count_fsb);
715 if (i_size > offset + count)
716 i_size = offset + count;
717
718 i_size = xfs_new_eof(ip, i_size);
719 if (i_size) {
720 ip->i_d.di_size = i_size;
721 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
722 }
723
724 error = xfs_bmap_finish(&tp, &free_list, &committed);
725 if (error)
726 goto error_on_bmapi_transaction;
727
728 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
729 xfs_iunlock(ip, XFS_ILOCK_EXCL);
730 if (error)
731 return XFS_ERROR(error);
732
733 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
734 return xfs_alert_fsblock_zero(ip, &imap);
735
736 if ((numblks_fsb = imap.br_blockcount) == 0) {
737 /*
738 * The numblks_fsb value should always get
739 * smaller, otherwise the loop is stuck.
740 */
741 ASSERT(imap.br_blockcount);
742 break;
743 }
744 offset_fsb += numblks_fsb;
745 count_fsb -= numblks_fsb;
746 } while (count_fsb > 0);
747
748 return 0;
749
750error_on_bmapi_transaction:
751 xfs_bmap_cancel(&free_list);
752 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
753 xfs_iunlock(ip, XFS_ILOCK_EXCL);
754 return XFS_ERROR(error);
755}
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_bit.h"
21#include "xfs_log.h"
22#include "xfs_inum.h"
23#include "xfs_trans.h"
24#include "xfs_sb.h"
25#include "xfs_ag.h"
26#include "xfs_alloc.h"
27#include "xfs_quota.h"
28#include "xfs_mount.h"
29#include "xfs_bmap_btree.h"
30#include "xfs_alloc_btree.h"
31#include "xfs_ialloc_btree.h"
32#include "xfs_dinode.h"
33#include "xfs_inode.h"
34#include "xfs_btree.h"
35#include "xfs_bmap.h"
36#include "xfs_rtalloc.h"
37#include "xfs_error.h"
38#include "xfs_itable.h"
39#include "xfs_rw.h"
40#include "xfs_attr.h"
41#include "xfs_buf_item.h"
42#include "xfs_trans_space.h"
43#include "xfs_utils.h"
44#include "xfs_iomap.h"
45#include "xfs_trace.h"
46
47
48#define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
49 << mp->m_writeio_log)
50#define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP
51
52STATIC int
53xfs_iomap_eof_align_last_fsb(
54 xfs_mount_t *mp,
55 xfs_inode_t *ip,
56 xfs_extlen_t extsize,
57 xfs_fileoff_t *last_fsb)
58{
59 xfs_fileoff_t new_last_fsb = 0;
60 xfs_extlen_t align;
61 int eof, error;
62
63 if (XFS_IS_REALTIME_INODE(ip))
64 ;
65 /*
66 * If mounted with the "-o swalloc" option, roundup the allocation
67 * request to a stripe width boundary if the file size is >=
68 * stripe width and we are allocating past the allocation eof.
69 */
70 else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) &&
71 (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_swidth)))
72 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth);
73 /*
74 * Roundup the allocation request to a stripe unit (m_dalign) boundary
75 * if the file size is >= stripe unit size, and we are allocating past
76 * the allocation eof.
77 */
78 else if (mp->m_dalign && (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_dalign)))
79 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign);
80
81 /*
82 * Always round up the allocation request to an extent boundary
83 * (when file on a real-time subvolume or has di_extsize hint).
84 */
85 if (extsize) {
86 if (new_last_fsb)
87 align = roundup_64(new_last_fsb, extsize);
88 else
89 align = extsize;
90 new_last_fsb = roundup_64(*last_fsb, align);
91 }
92
93 if (new_last_fsb) {
94 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
95 if (error)
96 return error;
97 if (eof)
98 *last_fsb = new_last_fsb;
99 }
100 return 0;
101}
102
103STATIC int
104xfs_alert_fsblock_zero(
105 xfs_inode_t *ip,
106 xfs_bmbt_irec_t *imap)
107{
108 xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO,
109 "Access to block zero in inode %llu "
110 "start_block: %llx start_off: %llx "
111 "blkcnt: %llx extent-state: %x\n",
112 (unsigned long long)ip->i_ino,
113 (unsigned long long)imap->br_startblock,
114 (unsigned long long)imap->br_startoff,
115 (unsigned long long)imap->br_blockcount,
116 imap->br_state);
117 return EFSCORRUPTED;
118}
119
120int
121xfs_iomap_write_direct(
122 xfs_inode_t *ip,
123 xfs_off_t offset,
124 size_t count,
125 xfs_bmbt_irec_t *imap,
126 int nmaps)
127{
128 xfs_mount_t *mp = ip->i_mount;
129 xfs_fileoff_t offset_fsb;
130 xfs_fileoff_t last_fsb;
131 xfs_filblks_t count_fsb, resaligned;
132 xfs_fsblock_t firstfsb;
133 xfs_extlen_t extsz, temp;
134 int nimaps;
135 int bmapi_flag;
136 int quota_flag;
137 int rt;
138 xfs_trans_t *tp;
139 xfs_bmap_free_t free_list;
140 uint qblocks, resblks, resrtextents;
141 int committed;
142 int error;
143
144 /*
145 * Make sure that the dquots are there. This doesn't hold
146 * the ilock across a disk read.
147 */
148 error = xfs_qm_dqattach_locked(ip, 0);
149 if (error)
150 return XFS_ERROR(error);
151
152 rt = XFS_IS_REALTIME_INODE(ip);
153 extsz = xfs_get_extsz_hint(ip);
154
155 offset_fsb = XFS_B_TO_FSBT(mp, offset);
156 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
157 if ((offset + count) > ip->i_size) {
158 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
159 if (error)
160 goto error_out;
161 } else {
162 if (nmaps && (imap->br_startblock == HOLESTARTBLOCK))
163 last_fsb = MIN(last_fsb, (xfs_fileoff_t)
164 imap->br_blockcount +
165 imap->br_startoff);
166 }
167 count_fsb = last_fsb - offset_fsb;
168 ASSERT(count_fsb > 0);
169
170 resaligned = count_fsb;
171 if (unlikely(extsz)) {
172 if ((temp = do_mod(offset_fsb, extsz)))
173 resaligned += temp;
174 if ((temp = do_mod(resaligned, extsz)))
175 resaligned += extsz - temp;
176 }
177
178 if (unlikely(rt)) {
179 resrtextents = qblocks = resaligned;
180 resrtextents /= mp->m_sb.sb_rextsize;
181 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
182 quota_flag = XFS_QMOPT_RES_RTBLKS;
183 } else {
184 resrtextents = 0;
185 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
186 quota_flag = XFS_QMOPT_RES_REGBLKS;
187 }
188
189 /*
190 * Allocate and setup the transaction
191 */
192 xfs_iunlock(ip, XFS_ILOCK_EXCL);
193 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
194 error = xfs_trans_reserve(tp, resblks,
195 XFS_WRITE_LOG_RES(mp), resrtextents,
196 XFS_TRANS_PERM_LOG_RES,
197 XFS_WRITE_LOG_COUNT);
198 /*
199 * Check for running out of space, note: need lock to return
200 */
201 if (error)
202 xfs_trans_cancel(tp, 0);
203 xfs_ilock(ip, XFS_ILOCK_EXCL);
204 if (error)
205 goto error_out;
206
207 error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
208 if (error)
209 goto error1;
210
211 xfs_trans_ijoin(tp, ip);
212
213 bmapi_flag = XFS_BMAPI_WRITE;
214 if (offset < ip->i_size || extsz)
215 bmapi_flag |= XFS_BMAPI_PREALLOC;
216
217 /*
218 * Issue the xfs_bmapi() call to allocate the blocks.
219 *
220 * From this point onwards we overwrite the imap pointer that the
221 * caller gave to us.
222 */
223 xfs_bmap_init(&free_list, &firstfsb);
224 nimaps = 1;
225 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, bmapi_flag,
226 &firstfsb, 0, imap, &nimaps, &free_list);
227 if (error)
228 goto error0;
229
230 /*
231 * Complete the transaction
232 */
233 error = xfs_bmap_finish(&tp, &free_list, &committed);
234 if (error)
235 goto error0;
236 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
237 if (error)
238 goto error_out;
239
240 /*
241 * Copy any maps to caller's array and return any error.
242 */
243 if (nimaps == 0) {
244 error = ENOSPC;
245 goto error_out;
246 }
247
248 if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) {
249 error = xfs_alert_fsblock_zero(ip, imap);
250 goto error_out;
251 }
252
253 return 0;
254
255error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
256 xfs_bmap_cancel(&free_list);
257 xfs_trans_unreserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
258
259error1: /* Just cancel transaction */
260 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
261
262error_out:
263 return XFS_ERROR(error);
264}
265
266/*
267 * If the caller is doing a write at the end of the file, then extend the
268 * allocation out to the file system's write iosize. We clean up any extra
269 * space left over when the file is closed in xfs_inactive().
270 *
271 * If we find we already have delalloc preallocation beyond EOF, don't do more
272 * preallocation as it it not needed.
273 */
274STATIC int
275xfs_iomap_eof_want_preallocate(
276 xfs_mount_t *mp,
277 xfs_inode_t *ip,
278 xfs_off_t offset,
279 size_t count,
280 xfs_bmbt_irec_t *imap,
281 int nimaps,
282 int *prealloc)
283{
284 xfs_fileoff_t start_fsb;
285 xfs_filblks_t count_fsb;
286 xfs_fsblock_t firstblock;
287 int n, error, imaps;
288 int found_delalloc = 0;
289
290 *prealloc = 0;
291 if ((offset + count) <= ip->i_size)
292 return 0;
293
294 /*
295 * If there are any real blocks past eof, then don't
296 * do any speculative allocation.
297 */
298 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
299 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
300 while (count_fsb > 0) {
301 imaps = nimaps;
302 firstblock = NULLFSBLOCK;
303 error = xfs_bmapi(NULL, ip, start_fsb, count_fsb, 0,
304 &firstblock, 0, imap, &imaps, NULL);
305 if (error)
306 return error;
307 for (n = 0; n < imaps; n++) {
308 if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
309 (imap[n].br_startblock != DELAYSTARTBLOCK))
310 return 0;
311 start_fsb += imap[n].br_blockcount;
312 count_fsb -= imap[n].br_blockcount;
313
314 if (imap[n].br_startblock == DELAYSTARTBLOCK)
315 found_delalloc = 1;
316 }
317 }
318 if (!found_delalloc)
319 *prealloc = 1;
320 return 0;
321}
322
323/*
324 * If we don't have a user specified preallocation size, dynamically increase
325 * the preallocation size as the size of the file grows. Cap the maximum size
326 * at a single extent or less if the filesystem is near full. The closer the
327 * filesystem is to full, the smaller the maximum prealocation.
328 */
329STATIC xfs_fsblock_t
330xfs_iomap_prealloc_size(
331 struct xfs_mount *mp,
332 struct xfs_inode *ip)
333{
334 xfs_fsblock_t alloc_blocks = 0;
335
336 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
337 int shift = 0;
338 int64_t freesp;
339
340 /*
341 * rounddown_pow_of_two() returns an undefined result
342 * if we pass in alloc_blocks = 0. Hence the "+ 1" to
343 * ensure we always pass in a non-zero value.
344 */
345 alloc_blocks = XFS_B_TO_FSB(mp, ip->i_size) + 1;
346 alloc_blocks = XFS_FILEOFF_MIN(MAXEXTLEN,
347 rounddown_pow_of_two(alloc_blocks));
348
349 xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);
350 freesp = mp->m_sb.sb_fdblocks;
351 if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) {
352 shift = 2;
353 if (freesp < mp->m_low_space[XFS_LOWSP_4_PCNT])
354 shift++;
355 if (freesp < mp->m_low_space[XFS_LOWSP_3_PCNT])
356 shift++;
357 if (freesp < mp->m_low_space[XFS_LOWSP_2_PCNT])
358 shift++;
359 if (freesp < mp->m_low_space[XFS_LOWSP_1_PCNT])
360 shift++;
361 }
362 if (shift)
363 alloc_blocks >>= shift;
364 }
365
366 if (alloc_blocks < mp->m_writeio_blocks)
367 alloc_blocks = mp->m_writeio_blocks;
368
369 return alloc_blocks;
370}
371
372int
373xfs_iomap_write_delay(
374 xfs_inode_t *ip,
375 xfs_off_t offset,
376 size_t count,
377 xfs_bmbt_irec_t *ret_imap)
378{
379 xfs_mount_t *mp = ip->i_mount;
380 xfs_fileoff_t offset_fsb;
381 xfs_fileoff_t last_fsb;
382 xfs_off_t aligned_offset;
383 xfs_fileoff_t ioalign;
384 xfs_fsblock_t firstblock;
385 xfs_extlen_t extsz;
386 int nimaps;
387 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
388 int prealloc, flushed = 0;
389 int error;
390
391 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
392
393 /*
394 * Make sure that the dquots are there. This doesn't hold
395 * the ilock across a disk read.
396 */
397 error = xfs_qm_dqattach_locked(ip, 0);
398 if (error)
399 return XFS_ERROR(error);
400
401 extsz = xfs_get_extsz_hint(ip);
402 offset_fsb = XFS_B_TO_FSBT(mp, offset);
403
404
405 error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count,
406 imap, XFS_WRITE_IMAPS, &prealloc);
407 if (error)
408 return error;
409
410retry:
411 if (prealloc) {
412 xfs_fsblock_t alloc_blocks = xfs_iomap_prealloc_size(mp, ip);
413
414 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
415 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
416 last_fsb = ioalign + alloc_blocks;
417 } else {
418 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
419 }
420
421 if (prealloc || extsz) {
422 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
423 if (error)
424 return error;
425 }
426
427 nimaps = XFS_WRITE_IMAPS;
428 firstblock = NULLFSBLOCK;
429 error = xfs_bmapi(NULL, ip, offset_fsb,
430 (xfs_filblks_t)(last_fsb - offset_fsb),
431 XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
432 XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
433 &nimaps, NULL);
434 switch (error) {
435 case 0:
436 case ENOSPC:
437 case EDQUOT:
438 break;
439 default:
440 return XFS_ERROR(error);
441 }
442
443 /*
444 * If bmapi returned us nothing, we got either ENOSPC or EDQUOT. For
445 * ENOSPC, * flush all other inodes with delalloc blocks to free up
446 * some of the excess reserved metadata space. For both cases, retry
447 * without EOF preallocation.
448 */
449 if (nimaps == 0) {
450 trace_xfs_delalloc_enospc(ip, offset, count);
451 if (flushed)
452 return XFS_ERROR(error ? error : ENOSPC);
453
454 if (error == ENOSPC) {
455 xfs_iunlock(ip, XFS_ILOCK_EXCL);
456 xfs_flush_inodes(ip);
457 xfs_ilock(ip, XFS_ILOCK_EXCL);
458 }
459
460 flushed = 1;
461 error = 0;
462 prealloc = 0;
463 goto retry;
464 }
465
466 if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip)))
467 return xfs_alert_fsblock_zero(ip, &imap[0]);
468
469 *ret_imap = imap[0];
470 return 0;
471}
472
473/*
474 * Pass in a delayed allocate extent, convert it to real extents;
475 * return to the caller the extent we create which maps on top of
476 * the originating callers request.
477 *
478 * Called without a lock on the inode.
479 *
480 * We no longer bother to look at the incoming map - all we have to
481 * guarantee is that whatever we allocate fills the required range.
482 */
483int
484xfs_iomap_write_allocate(
485 xfs_inode_t *ip,
486 xfs_off_t offset,
487 size_t count,
488 xfs_bmbt_irec_t *imap)
489{
490 xfs_mount_t *mp = ip->i_mount;
491 xfs_fileoff_t offset_fsb, last_block;
492 xfs_fileoff_t end_fsb, map_start_fsb;
493 xfs_fsblock_t first_block;
494 xfs_bmap_free_t free_list;
495 xfs_filblks_t count_fsb;
496 xfs_trans_t *tp;
497 int nimaps, committed;
498 int error = 0;
499 int nres;
500
501 /*
502 * Make sure that the dquots are there.
503 */
504 error = xfs_qm_dqattach(ip, 0);
505 if (error)
506 return XFS_ERROR(error);
507
508 offset_fsb = XFS_B_TO_FSBT(mp, offset);
509 count_fsb = imap->br_blockcount;
510 map_start_fsb = imap->br_startoff;
511
512 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
513
514 while (count_fsb != 0) {
515 /*
516 * Set up a transaction with which to allocate the
517 * backing store for the file. Do allocations in a
518 * loop until we get some space in the range we are
519 * interested in. The other space that might be allocated
520 * is in the delayed allocation extent on which we sit
521 * but before our buffer starts.
522 */
523
524 nimaps = 0;
525 while (nimaps == 0) {
526 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
527 tp->t_flags |= XFS_TRANS_RESERVE;
528 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
529 error = xfs_trans_reserve(tp, nres,
530 XFS_WRITE_LOG_RES(mp),
531 0, XFS_TRANS_PERM_LOG_RES,
532 XFS_WRITE_LOG_COUNT);
533 if (error) {
534 xfs_trans_cancel(tp, 0);
535 return XFS_ERROR(error);
536 }
537 xfs_ilock(ip, XFS_ILOCK_EXCL);
538 xfs_trans_ijoin(tp, ip);
539
540 xfs_bmap_init(&free_list, &first_block);
541
542 /*
543 * it is possible that the extents have changed since
544 * we did the read call as we dropped the ilock for a
545 * while. We have to be careful about truncates or hole
546 * punchs here - we are not allowed to allocate
547 * non-delalloc blocks here.
548 *
549 * The only protection against truncation is the pages
550 * for the range we are being asked to convert are
551 * locked and hence a truncate will block on them
552 * first.
553 *
554 * As a result, if we go beyond the range we really
555 * need and hit an delalloc extent boundary followed by
556 * a hole while we have excess blocks in the map, we
557 * will fill the hole incorrectly and overrun the
558 * transaction reservation.
559 *
560 * Using a single map prevents this as we are forced to
561 * check each map we look for overlap with the desired
562 * range and abort as soon as we find it. Also, given
563 * that we only return a single map, having one beyond
564 * what we can return is probably a bit silly.
565 *
566 * We also need to check that we don't go beyond EOF;
567 * this is a truncate optimisation as a truncate sets
568 * the new file size before block on the pages we
569 * currently have locked under writeback. Because they
570 * are about to be tossed, we don't need to write them
571 * back....
572 */
573 nimaps = 1;
574 end_fsb = XFS_B_TO_FSB(mp, ip->i_size);
575 error = xfs_bmap_last_offset(NULL, ip, &last_block,
576 XFS_DATA_FORK);
577 if (error)
578 goto trans_cancel;
579
580 last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
581 if ((map_start_fsb + count_fsb) > last_block) {
582 count_fsb = last_block - map_start_fsb;
583 if (count_fsb == 0) {
584 error = EAGAIN;
585 goto trans_cancel;
586 }
587 }
588
589 /*
590 * Go get the actual blocks.
591 *
592 * From this point onwards we overwrite the imap
593 * pointer that the caller gave to us.
594 */
595 error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
596 XFS_BMAPI_WRITE, &first_block, 1,
597 imap, &nimaps, &free_list);
598 if (error)
599 goto trans_cancel;
600
601 error = xfs_bmap_finish(&tp, &free_list, &committed);
602 if (error)
603 goto trans_cancel;
604
605 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
606 if (error)
607 goto error0;
608
609 xfs_iunlock(ip, XFS_ILOCK_EXCL);
610 }
611
612 /*
613 * See if we were able to allocate an extent that
614 * covers at least part of the callers request
615 */
616 if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip)))
617 return xfs_alert_fsblock_zero(ip, imap);
618
619 if ((offset_fsb >= imap->br_startoff) &&
620 (offset_fsb < (imap->br_startoff +
621 imap->br_blockcount))) {
622 XFS_STATS_INC(xs_xstrat_quick);
623 return 0;
624 }
625
626 /*
627 * So far we have not mapped the requested part of the
628 * file, just surrounding data, try again.
629 */
630 count_fsb -= imap->br_blockcount;
631 map_start_fsb = imap->br_startoff + imap->br_blockcount;
632 }
633
634trans_cancel:
635 xfs_bmap_cancel(&free_list);
636 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
637error0:
638 xfs_iunlock(ip, XFS_ILOCK_EXCL);
639 return XFS_ERROR(error);
640}
641
642int
643xfs_iomap_write_unwritten(
644 xfs_inode_t *ip,
645 xfs_off_t offset,
646 size_t count)
647{
648 xfs_mount_t *mp = ip->i_mount;
649 xfs_fileoff_t offset_fsb;
650 xfs_filblks_t count_fsb;
651 xfs_filblks_t numblks_fsb;
652 xfs_fsblock_t firstfsb;
653 int nimaps;
654 xfs_trans_t *tp;
655 xfs_bmbt_irec_t imap;
656 xfs_bmap_free_t free_list;
657 uint resblks;
658 int committed;
659 int error;
660
661 trace_xfs_unwritten_convert(ip, offset, count);
662
663 offset_fsb = XFS_B_TO_FSBT(mp, offset);
664 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
665 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
666
667 /*
668 * Reserve enough blocks in this transaction for two complete extent
669 * btree splits. We may be converting the middle part of an unwritten
670 * extent and in this case we will insert two new extents in the btree
671 * each of which could cause a full split.
672 *
673 * This reservation amount will be used in the first call to
674 * xfs_bmbt_split() to select an AG with enough space to satisfy the
675 * rest of the operation.
676 */
677 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
678
679 do {
680 /*
681 * set up a transaction to convert the range of extents
682 * from unwritten to real. Do allocations in a loop until
683 * we have covered the range passed in.
684 *
685 * Note that we open code the transaction allocation here
686 * to pass KM_NOFS--we can't risk to recursing back into
687 * the filesystem here as we might be asked to write out
688 * the same inode that we complete here and might deadlock
689 * on the iolock.
690 */
691 xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
692 tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS);
693 tp->t_flags |= XFS_TRANS_RESERVE;
694 error = xfs_trans_reserve(tp, resblks,
695 XFS_WRITE_LOG_RES(mp), 0,
696 XFS_TRANS_PERM_LOG_RES,
697 XFS_WRITE_LOG_COUNT);
698 if (error) {
699 xfs_trans_cancel(tp, 0);
700 return XFS_ERROR(error);
701 }
702
703 xfs_ilock(ip, XFS_ILOCK_EXCL);
704 xfs_trans_ijoin(tp, ip);
705
706 /*
707 * Modify the unwritten extent state of the buffer.
708 */
709 xfs_bmap_init(&free_list, &firstfsb);
710 nimaps = 1;
711 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
712 XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb,
713 1, &imap, &nimaps, &free_list);
714 if (error)
715 goto error_on_bmapi_transaction;
716
717 error = xfs_bmap_finish(&(tp), &(free_list), &committed);
718 if (error)
719 goto error_on_bmapi_transaction;
720
721 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
722 xfs_iunlock(ip, XFS_ILOCK_EXCL);
723 if (error)
724 return XFS_ERROR(error);
725
726 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
727 return xfs_alert_fsblock_zero(ip, &imap);
728
729 if ((numblks_fsb = imap.br_blockcount) == 0) {
730 /*
731 * The numblks_fsb value should always get
732 * smaller, otherwise the loop is stuck.
733 */
734 ASSERT(imap.br_blockcount);
735 break;
736 }
737 offset_fsb += numblks_fsb;
738 count_fsb -= numblks_fsb;
739 } while (count_fsb > 0);
740
741 return 0;
742
743error_on_bmapi_transaction:
744 xfs_bmap_cancel(&free_list);
745 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
746 xfs_iunlock(ip, XFS_ILOCK_EXCL);
747 return XFS_ERROR(error);
748}