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_inode_item.h"
35 #include "xfs_btree.h"
36 #include "xfs_bmap.h"
37 #include "xfs_rtalloc.h"
38 #include "xfs_error.h"
39 #include "xfs_itable.h"
40 #include "xfs_rw.h"
41 #include "xfs_attr.h"
42 #include "xfs_buf_item.h"
43 #include "xfs_trans_space.h"
44 #include "xfs_utils.h"
45 #include "xfs_iomap.h"
46 #include "xfs_trace.h"
47
48
49 #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
50 << mp->m_writeio_log)
51 #define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP
52
53 STATIC int
xfs_iomap_eof_align_last_fsb(xfs_mount_t * mp,xfs_inode_t * ip,xfs_extlen_t extsize,xfs_fileoff_t * last_fsb)54 xfs_iomap_eof_align_last_fsb(
55 xfs_mount_t *mp,
56 xfs_inode_t *ip,
57 xfs_extlen_t extsize,
58 xfs_fileoff_t *last_fsb)
59 {
60 xfs_fileoff_t new_last_fsb = 0;
61 xfs_extlen_t align = 0;
62 int eof, error;
63
64 if (!XFS_IS_REALTIME_INODE(ip)) {
65 /*
66 * Round up the allocation request to a stripe unit
67 * (m_dalign) boundary if the file size is >= stripe unit
68 * size, and we are allocating past the allocation eof.
69 *
70 * If mounted with the "-o swalloc" option the alignment is
71 * increased from the strip unit size to the stripe width.
72 */
73 if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC))
74 align = mp->m_swidth;
75 else if (mp->m_dalign)
76 align = mp->m_dalign;
77
78 if (align && XFS_ISIZE(ip) >= XFS_FSB_TO_B(mp, align))
79 new_last_fsb = roundup_64(*last_fsb, align);
80 }
81
82 /*
83 * Always round up the allocation request to an extent boundary
84 * (when file on a real-time subvolume or has di_extsize hint).
85 */
86 if (extsize) {
87 if (new_last_fsb)
88 align = roundup_64(new_last_fsb, extsize);
89 else
90 align = extsize;
91 new_last_fsb = roundup_64(*last_fsb, align);
92 }
93
94 if (new_last_fsb) {
95 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
96 if (error)
97 return error;
98 if (eof)
99 *last_fsb = new_last_fsb;
100 }
101 return 0;
102 }
103
104 STATIC int
xfs_alert_fsblock_zero(xfs_inode_t * ip,xfs_bmbt_irec_t * imap)105 xfs_alert_fsblock_zero(
106 xfs_inode_t *ip,
107 xfs_bmbt_irec_t *imap)
108 {
109 xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO,
110 "Access to block zero in inode %llu "
111 "start_block: %llx start_off: %llx "
112 "blkcnt: %llx extent-state: %x\n",
113 (unsigned long long)ip->i_ino,
114 (unsigned long long)imap->br_startblock,
115 (unsigned long long)imap->br_startoff,
116 (unsigned long long)imap->br_blockcount,
117 imap->br_state);
118 return EFSCORRUPTED;
119 }
120
121 int
xfs_iomap_write_direct(xfs_inode_t * ip,xfs_off_t offset,size_t count,xfs_bmbt_irec_t * imap,int nmaps)122 xfs_iomap_write_direct(
123 xfs_inode_t *ip,
124 xfs_off_t offset,
125 size_t count,
126 xfs_bmbt_irec_t *imap,
127 int nmaps)
128 {
129 xfs_mount_t *mp = ip->i_mount;
130 xfs_fileoff_t offset_fsb;
131 xfs_fileoff_t last_fsb;
132 xfs_filblks_t count_fsb, resaligned;
133 xfs_fsblock_t firstfsb;
134 xfs_extlen_t extsz, temp;
135 int nimaps;
136 int bmapi_flag;
137 int quota_flag;
138 int rt;
139 xfs_trans_t *tp;
140 xfs_bmap_free_t free_list;
141 uint qblocks, resblks, resrtextents;
142 int committed;
143 int error;
144
145 /*
146 * Make sure that the dquots are there. This doesn't hold
147 * the ilock across a disk read.
148 */
149 error = xfs_qm_dqattach_locked(ip, 0);
150 if (error)
151 return XFS_ERROR(error);
152
153 rt = XFS_IS_REALTIME_INODE(ip);
154 extsz = xfs_get_extsz_hint(ip);
155
156 offset_fsb = XFS_B_TO_FSBT(mp, offset);
157 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
158 if ((offset + count) > XFS_ISIZE(ip)) {
159 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
160 if (error)
161 goto error_out;
162 } else {
163 if (nmaps && (imap->br_startblock == HOLESTARTBLOCK))
164 last_fsb = MIN(last_fsb, (xfs_fileoff_t)
165 imap->br_blockcount +
166 imap->br_startoff);
167 }
168 count_fsb = last_fsb - offset_fsb;
169 ASSERT(count_fsb > 0);
170
171 resaligned = count_fsb;
172 if (unlikely(extsz)) {
173 if ((temp = do_mod(offset_fsb, extsz)))
174 resaligned += temp;
175 if ((temp = do_mod(resaligned, extsz)))
176 resaligned += extsz - temp;
177 }
178
179 if (unlikely(rt)) {
180 resrtextents = qblocks = resaligned;
181 resrtextents /= mp->m_sb.sb_rextsize;
182 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
183 quota_flag = XFS_QMOPT_RES_RTBLKS;
184 } else {
185 resrtextents = 0;
186 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
187 quota_flag = XFS_QMOPT_RES_REGBLKS;
188 }
189
190 /*
191 * Allocate and setup the transaction
192 */
193 xfs_iunlock(ip, XFS_ILOCK_EXCL);
194 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
195 error = xfs_trans_reserve(tp, resblks,
196 XFS_WRITE_LOG_RES(mp), resrtextents,
197 XFS_TRANS_PERM_LOG_RES,
198 XFS_WRITE_LOG_COUNT);
199 /*
200 * Check for running out of space, note: need lock to return
201 */
202 if (error)
203 xfs_trans_cancel(tp, 0);
204 xfs_ilock(ip, XFS_ILOCK_EXCL);
205 if (error)
206 goto error_out;
207
208 error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
209 if (error)
210 goto error1;
211
212 xfs_trans_ijoin(tp, ip, 0);
213
214 bmapi_flag = 0;
215 if (offset < XFS_ISIZE(ip) || extsz)
216 bmapi_flag |= XFS_BMAPI_PREALLOC;
217
218 /*
219 * From this point onwards we overwrite the imap pointer that the
220 * caller gave to us.
221 */
222 xfs_bmap_init(&free_list, &firstfsb);
223 nimaps = 1;
224 error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, bmapi_flag,
225 &firstfsb, 0, imap, &nimaps, &free_list);
226 if (error)
227 goto error0;
228
229 /*
230 * Complete the transaction
231 */
232 error = xfs_bmap_finish(&tp, &free_list, &committed);
233 if (error)
234 goto error0;
235 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
236 if (error)
237 goto error_out;
238
239 /*
240 * Copy any maps to caller's array and return any error.
241 */
242 if (nimaps == 0) {
243 error = ENOSPC;
244 goto error_out;
245 }
246
247 if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) {
248 error = xfs_alert_fsblock_zero(ip, imap);
249 goto error_out;
250 }
251
252 return 0;
253
254 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
255 xfs_bmap_cancel(&free_list);
256 xfs_trans_unreserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
257
258 error1: /* Just cancel transaction */
259 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
260
261 error_out:
262 return XFS_ERROR(error);
263 }
264
265 /*
266 * If the caller is doing a write at the end of the file, then extend the
267 * allocation out to the file system's write iosize. We clean up any extra
268 * space left over when the file is closed in xfs_inactive().
269 *
270 * If we find we already have delalloc preallocation beyond EOF, don't do more
271 * preallocation as it it not needed.
272 */
273 STATIC int
xfs_iomap_eof_want_preallocate(xfs_mount_t * mp,xfs_inode_t * ip,xfs_off_t offset,size_t count,xfs_bmbt_irec_t * imap,int nimaps,int * prealloc)274 xfs_iomap_eof_want_preallocate(
275 xfs_mount_t *mp,
276 xfs_inode_t *ip,
277 xfs_off_t offset,
278 size_t count,
279 xfs_bmbt_irec_t *imap,
280 int nimaps,
281 int *prealloc)
282 {
283 xfs_fileoff_t start_fsb;
284 xfs_filblks_t count_fsb;
285 xfs_fsblock_t firstblock;
286 int n, error, imaps;
287 int found_delalloc = 0;
288
289 *prealloc = 0;
290 if (offset + count <= XFS_ISIZE(ip))
291 return 0;
292
293 /*
294 * If there are any real blocks past eof, then don't
295 * do any speculative allocation.
296 */
297 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
298 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
299 while (count_fsb > 0) {
300 imaps = nimaps;
301 firstblock = NULLFSBLOCK;
302 error = xfs_bmapi_read(ip, start_fsb, count_fsb, imap, &imaps,
303 0);
304 if (error)
305 return error;
306 for (n = 0; n < imaps; n++) {
307 if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
308 (imap[n].br_startblock != DELAYSTARTBLOCK))
309 return 0;
310 start_fsb += imap[n].br_blockcount;
311 count_fsb -= imap[n].br_blockcount;
312
313 if (imap[n].br_startblock == DELAYSTARTBLOCK)
314 found_delalloc = 1;
315 }
316 }
317 if (!found_delalloc)
318 *prealloc = 1;
319 return 0;
320 }
321
322 /*
323 * If we don't have a user specified preallocation size, dynamically increase
324 * the preallocation size as the size of the file grows. Cap the maximum size
325 * at a single extent or less if the filesystem is near full. The closer the
326 * filesystem is to full, the smaller the maximum prealocation.
327 */
328 STATIC xfs_fsblock_t
xfs_iomap_prealloc_size(struct xfs_mount * mp,struct xfs_inode * ip)329 xfs_iomap_prealloc_size(
330 struct xfs_mount *mp,
331 struct xfs_inode *ip)
332 {
333 xfs_fsblock_t alloc_blocks = 0;
334
335 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
336 int shift = 0;
337 int64_t freesp;
338
339 /*
340 * rounddown_pow_of_two() returns an undefined result
341 * if we pass in alloc_blocks = 0. Hence the "+ 1" to
342 * ensure we always pass in a non-zero value.
343 */
344 alloc_blocks = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)) + 1;
345 alloc_blocks = XFS_FILEOFF_MIN(MAXEXTLEN,
346 rounddown_pow_of_two(alloc_blocks));
347
348 xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT);
349 freesp = mp->m_sb.sb_fdblocks;
350 if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) {
351 shift = 2;
352 if (freesp < mp->m_low_space[XFS_LOWSP_4_PCNT])
353 shift++;
354 if (freesp < mp->m_low_space[XFS_LOWSP_3_PCNT])
355 shift++;
356 if (freesp < mp->m_low_space[XFS_LOWSP_2_PCNT])
357 shift++;
358 if (freesp < mp->m_low_space[XFS_LOWSP_1_PCNT])
359 shift++;
360 }
361 if (shift)
362 alloc_blocks >>= shift;
363 }
364
365 if (alloc_blocks < mp->m_writeio_blocks)
366 alloc_blocks = mp->m_writeio_blocks;
367
368 return alloc_blocks;
369 }
370
371 int
xfs_iomap_write_delay(xfs_inode_t * ip,xfs_off_t offset,size_t count,xfs_bmbt_irec_t * ret_imap)372 xfs_iomap_write_delay(
373 xfs_inode_t *ip,
374 xfs_off_t offset,
375 size_t count,
376 xfs_bmbt_irec_t *ret_imap)
377 {
378 xfs_mount_t *mp = ip->i_mount;
379 xfs_fileoff_t offset_fsb;
380 xfs_fileoff_t last_fsb;
381 xfs_off_t aligned_offset;
382 xfs_fileoff_t ioalign;
383 xfs_extlen_t extsz;
384 int nimaps;
385 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
386 int prealloc, flushed = 0;
387 int error;
388
389 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
390
391 /*
392 * Make sure that the dquots are there. This doesn't hold
393 * the ilock across a disk read.
394 */
395 error = xfs_qm_dqattach_locked(ip, 0);
396 if (error)
397 return XFS_ERROR(error);
398
399 extsz = xfs_get_extsz_hint(ip);
400 offset_fsb = XFS_B_TO_FSBT(mp, offset);
401
402
403 error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count,
404 imap, XFS_WRITE_IMAPS, &prealloc);
405 if (error)
406 return error;
407
408 retry:
409 if (prealloc) {
410 xfs_fsblock_t alloc_blocks = xfs_iomap_prealloc_size(mp, ip);
411
412 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
413 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
414 last_fsb = ioalign + alloc_blocks;
415 } else {
416 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
417 }
418
419 if (prealloc || extsz) {
420 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
421 if (error)
422 return error;
423 }
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. For
439 * ENOSPC, * flush all other inodes with delalloc blocks to free up
440 * some of the excess reserved metadata space. For both cases, retry
441 * without EOF preallocation.
442 */
443 if (nimaps == 0) {
444 trace_xfs_delalloc_enospc(ip, offset, count);
445 if (flushed)
446 return XFS_ERROR(error ? error : ENOSPC);
447
448 if (error == ENOSPC) {
449 xfs_iunlock(ip, XFS_ILOCK_EXCL);
450 xfs_flush_inodes(ip);
451 xfs_ilock(ip, XFS_ILOCK_EXCL);
452 }
453
454 flushed = 1;
455 error = 0;
456 prealloc = 0;
457 goto retry;
458 }
459
460 if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip)))
461 return xfs_alert_fsblock_zero(ip, &imap[0]);
462
463 *ret_imap = imap[0];
464 return 0;
465 }
466
467 /*
468 * Pass in a delayed allocate extent, convert it to real extents;
469 * return to the caller the extent we create which maps on top of
470 * the originating callers request.
471 *
472 * Called without a lock on the inode.
473 *
474 * We no longer bother to look at the incoming map - all we have to
475 * guarantee is that whatever we allocate fills the required range.
476 */
477 int
xfs_iomap_write_allocate(xfs_inode_t * ip,xfs_off_t offset,size_t count,xfs_bmbt_irec_t * imap)478 xfs_iomap_write_allocate(
479 xfs_inode_t *ip,
480 xfs_off_t offset,
481 size_t count,
482 xfs_bmbt_irec_t *imap)
483 {
484 xfs_mount_t *mp = ip->i_mount;
485 xfs_fileoff_t offset_fsb, last_block;
486 xfs_fileoff_t end_fsb, map_start_fsb;
487 xfs_fsblock_t first_block;
488 xfs_bmap_free_t free_list;
489 xfs_filblks_t count_fsb;
490 xfs_trans_t *tp;
491 int nimaps, committed;
492 int error = 0;
493 int nres;
494
495 /*
496 * Make sure that the dquots are there.
497 */
498 error = xfs_qm_dqattach(ip, 0);
499 if (error)
500 return XFS_ERROR(error);
501
502 offset_fsb = XFS_B_TO_FSBT(mp, offset);
503 count_fsb = imap->br_blockcount;
504 map_start_fsb = imap->br_startoff;
505
506 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
507
508 while (count_fsb != 0) {
509 /*
510 * Set up a transaction with which to allocate the
511 * backing store for the file. Do allocations in a
512 * loop until we get some space in the range we are
513 * interested in. The other space that might be allocated
514 * is in the delayed allocation extent on which we sit
515 * but before our buffer starts.
516 */
517
518 nimaps = 0;
519 while (nimaps == 0) {
520 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
521 tp->t_flags |= XFS_TRANS_RESERVE;
522 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
523 error = xfs_trans_reserve(tp, nres,
524 XFS_WRITE_LOG_RES(mp),
525 0, XFS_TRANS_PERM_LOG_RES,
526 XFS_WRITE_LOG_COUNT);
527 if (error) {
528 xfs_trans_cancel(tp, 0);
529 return XFS_ERROR(error);
530 }
531 xfs_ilock(ip, XFS_ILOCK_EXCL);
532 xfs_trans_ijoin(tp, ip, 0);
533
534 xfs_bmap_init(&free_list, &first_block);
535
536 /*
537 * it is possible that the extents have changed since
538 * we did the read call as we dropped the ilock for a
539 * while. We have to be careful about truncates or hole
540 * punchs here - we are not allowed to allocate
541 * non-delalloc blocks here.
542 *
543 * The only protection against truncation is the pages
544 * for the range we are being asked to convert are
545 * locked and hence a truncate will block on them
546 * first.
547 *
548 * As a result, if we go beyond the range we really
549 * need and hit an delalloc extent boundary followed by
550 * a hole while we have excess blocks in the map, we
551 * will fill the hole incorrectly and overrun the
552 * transaction reservation.
553 *
554 * Using a single map prevents this as we are forced to
555 * check each map we look for overlap with the desired
556 * range and abort as soon as we find it. Also, given
557 * that we only return a single map, having one beyond
558 * what we can return is probably a bit silly.
559 *
560 * We also need to check that we don't go beyond EOF;
561 * this is a truncate optimisation as a truncate sets
562 * the new file size before block on the pages we
563 * currently have locked under writeback. Because they
564 * are about to be tossed, we don't need to write them
565 * back....
566 */
567 nimaps = 1;
568 end_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
569 error = xfs_bmap_last_offset(NULL, ip, &last_block,
570 XFS_DATA_FORK);
571 if (error)
572 goto trans_cancel;
573
574 last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
575 if ((map_start_fsb + count_fsb) > last_block) {
576 count_fsb = last_block - map_start_fsb;
577 if (count_fsb == 0) {
578 error = EAGAIN;
579 goto trans_cancel;
580 }
581 }
582
583 /*
584 * From this point onwards we overwrite the imap
585 * pointer that the caller gave to us.
586 */
587 error = xfs_bmapi_write(tp, ip, map_start_fsb,
588 count_fsb, 0, &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
xfs_iomap_write_unwritten(xfs_inode_t * ip,xfs_off_t offset,size_t count)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 xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
685 tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS);
686 tp->t_flags |= XFS_TRANS_RESERVE;
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 }
757