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Merge branch 'fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6
[mirror_ubuntu-bionic-kernel.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_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_dir2.h"
27 #include "xfs_alloc.h"
28 #include "xfs_dmapi.h"
29 #include "xfs_quota.h"
30 #include "xfs_mount.h"
31 #include "xfs_bmap_btree.h"
32 #include "xfs_alloc_btree.h"
33 #include "xfs_ialloc_btree.h"
34 #include "xfs_dir2_sf.h"
35 #include "xfs_attr_sf.h"
36 #include "xfs_dinode.h"
37 #include "xfs_inode.h"
38 #include "xfs_ialloc.h"
39 #include "xfs_btree.h"
40 #include "xfs_bmap.h"
41 #include "xfs_rtalloc.h"
42 #include "xfs_error.h"
43 #include "xfs_itable.h"
44 #include "xfs_rw.h"
45 #include "xfs_acl.h"
46 #include "xfs_attr.h"
47 #include "xfs_buf_item.h"
48 #include "xfs_trans_space.h"
49 #include "xfs_utils.h"
50 #include "xfs_iomap.h"
51
52 #if defined(XFS_RW_TRACE)
53 void
54 xfs_iomap_enter_trace(
55 int tag,
56 xfs_inode_t *ip,
57 xfs_off_t offset,
58 ssize_t count)
59 {
60 if (!ip->i_rwtrace)
61 return;
62
63 ktrace_enter(ip->i_rwtrace,
64 (void *)((unsigned long)tag),
65 (void *)ip,
66 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
67 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
68 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
69 (void *)((unsigned long)(offset & 0xffffffff)),
70 (void *)((unsigned long)count),
71 (void *)((unsigned long)((ip->i_new_size >> 32) & 0xffffffff)),
72 (void *)((unsigned long)(ip->i_new_size & 0xffffffff)),
73 (void *)((unsigned long)current_pid()),
74 (void *)NULL,
75 (void *)NULL,
76 (void *)NULL,
77 (void *)NULL,
78 (void *)NULL,
79 (void *)NULL);
80 }
81
82 void
83 xfs_iomap_map_trace(
84 int tag,
85 xfs_inode_t *ip,
86 xfs_off_t offset,
87 ssize_t count,
88 xfs_iomap_t *iomapp,
89 xfs_bmbt_irec_t *imapp,
90 int flags)
91 {
92 if (!ip->i_rwtrace)
93 return;
94
95 ktrace_enter(ip->i_rwtrace,
96 (void *)((unsigned long)tag),
97 (void *)ip,
98 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
99 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
100 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
101 (void *)((unsigned long)(offset & 0xffffffff)),
102 (void *)((unsigned long)count),
103 (void *)((unsigned long)flags),
104 (void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)),
105 (void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)),
106 (void *)((unsigned long)(iomapp->iomap_delta)),
107 (void *)((unsigned long)(iomapp->iomap_bsize)),
108 (void *)((unsigned long)(iomapp->iomap_bn)),
109 (void *)(__psint_t)(imapp->br_startoff),
110 (void *)((unsigned long)(imapp->br_blockcount)),
111 (void *)(__psint_t)(imapp->br_startblock));
112 }
113 #else
114 #define xfs_iomap_enter_trace(tag, io, offset, count)
115 #define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags)
116 #endif
117
118 #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
119 << mp->m_writeio_log)
120 #define XFS_STRAT_WRITE_IMAPS 2
121 #define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP
122
123 STATIC int
124 xfs_imap_to_bmap(
125 xfs_inode_t *ip,
126 xfs_off_t offset,
127 xfs_bmbt_irec_t *imap,
128 xfs_iomap_t *iomapp,
129 int imaps, /* Number of imap entries */
130 int iomaps, /* Number of iomap entries */
131 int flags)
132 {
133 xfs_mount_t *mp = ip->i_mount;
134 int pbm;
135 xfs_fsblock_t start_block;
136
137
138 for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
139 iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
140 iomapp->iomap_delta = offset - iomapp->iomap_offset;
141 iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
142 iomapp->iomap_flags = flags;
143
144 if (XFS_IS_REALTIME_INODE(ip)) {
145 iomapp->iomap_flags |= IOMAP_REALTIME;
146 iomapp->iomap_target = mp->m_rtdev_targp;
147 } else {
148 iomapp->iomap_target = mp->m_ddev_targp;
149 }
150 start_block = imap->br_startblock;
151 if (start_block == HOLESTARTBLOCK) {
152 iomapp->iomap_bn = IOMAP_DADDR_NULL;
153 iomapp->iomap_flags |= IOMAP_HOLE;
154 } else if (start_block == DELAYSTARTBLOCK) {
155 iomapp->iomap_bn = IOMAP_DADDR_NULL;
156 iomapp->iomap_flags |= IOMAP_DELAY;
157 } else {
158 iomapp->iomap_bn = xfs_fsb_to_db(ip, start_block);
159 if (ISUNWRITTEN(imap))
160 iomapp->iomap_flags |= IOMAP_UNWRITTEN;
161 }
162
163 offset += iomapp->iomap_bsize - iomapp->iomap_delta;
164 }
165 return pbm; /* Return the number filled */
166 }
167
168 int
169 xfs_iomap(
170 xfs_inode_t *ip,
171 xfs_off_t offset,
172 ssize_t count,
173 int flags,
174 xfs_iomap_t *iomapp,
175 int *niomaps)
176 {
177 xfs_mount_t *mp = ip->i_mount;
178 xfs_fileoff_t offset_fsb, end_fsb;
179 int error = 0;
180 int lockmode = 0;
181 xfs_bmbt_irec_t imap;
182 int nimaps = 1;
183 int bmapi_flags = 0;
184 int iomap_flags = 0;
185
186 ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
187
188 if (XFS_FORCED_SHUTDOWN(mp))
189 return XFS_ERROR(EIO);
190
191 switch (flags & (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE)) {
192 case BMAPI_READ:
193 xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, ip, offset, count);
194 lockmode = xfs_ilock_map_shared(ip);
195 bmapi_flags = XFS_BMAPI_ENTIRE;
196 break;
197 case BMAPI_WRITE:
198 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, ip, offset, count);
199 lockmode = XFS_ILOCK_EXCL;
200 if (flags & BMAPI_IGNSTATE)
201 bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE;
202 xfs_ilock(ip, lockmode);
203 break;
204 case BMAPI_ALLOCATE:
205 xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, ip, offset, count);
206 lockmode = XFS_ILOCK_SHARED;
207 bmapi_flags = XFS_BMAPI_ENTIRE;
208
209 /* Attempt non-blocking lock */
210 if (flags & BMAPI_TRYLOCK) {
211 if (!xfs_ilock_nowait(ip, lockmode))
212 return XFS_ERROR(EAGAIN);
213 } else {
214 xfs_ilock(ip, lockmode);
215 }
216 break;
217 default:
218 BUG();
219 }
220
221 ASSERT(offset <= mp->m_maxioffset);
222 if ((xfs_fsize_t)offset + count > mp->m_maxioffset)
223 count = mp->m_maxioffset - offset;
224 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
225 offset_fsb = XFS_B_TO_FSBT(mp, offset);
226
227 error = xfs_bmapi(NULL, ip, offset_fsb,
228 (xfs_filblks_t)(end_fsb - offset_fsb),
229 bmapi_flags, NULL, 0, &imap,
230 &nimaps, NULL, NULL);
231
232 if (error)
233 goto out;
234
235 switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE)) {
236 case BMAPI_WRITE:
237 /* If we found an extent, return it */
238 if (nimaps &&
239 (imap.br_startblock != HOLESTARTBLOCK) &&
240 (imap.br_startblock != DELAYSTARTBLOCK)) {
241 xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, ip,
242 offset, count, iomapp, &imap, flags);
243 break;
244 }
245
246 if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
247 error = xfs_iomap_write_direct(ip, offset, count, flags,
248 &imap, &nimaps, nimaps);
249 } else {
250 error = xfs_iomap_write_delay(ip, offset, count, flags,
251 &imap, &nimaps);
252 }
253 if (!error) {
254 xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, ip,
255 offset, count, iomapp, &imap, flags);
256 }
257 iomap_flags = IOMAP_NEW;
258 break;
259 case BMAPI_ALLOCATE:
260 /* If we found an extent, return it */
261 xfs_iunlock(ip, lockmode);
262 lockmode = 0;
263
264 if (nimaps && !isnullstartblock(imap.br_startblock)) {
265 xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, ip,
266 offset, count, iomapp, &imap, flags);
267 break;
268 }
269
270 error = xfs_iomap_write_allocate(ip, offset, count,
271 &imap, &nimaps);
272 break;
273 }
274
275 if (nimaps) {
276 *niomaps = xfs_imap_to_bmap(ip, offset, &imap,
277 iomapp, nimaps, *niomaps, iomap_flags);
278 } else if (niomaps) {
279 *niomaps = 0;
280 }
281
282 out:
283 if (lockmode)
284 xfs_iunlock(ip, lockmode);
285 return XFS_ERROR(error);
286 }
287
288
289 STATIC int
290 xfs_iomap_eof_align_last_fsb(
291 xfs_mount_t *mp,
292 xfs_inode_t *ip,
293 xfs_extlen_t extsize,
294 xfs_fileoff_t *last_fsb)
295 {
296 xfs_fileoff_t new_last_fsb = 0;
297 xfs_extlen_t align;
298 int eof, error;
299
300 if (XFS_IS_REALTIME_INODE(ip))
301 ;
302 /*
303 * If mounted with the "-o swalloc" option, roundup the allocation
304 * request to a stripe width boundary if the file size is >=
305 * stripe width and we are allocating past the allocation eof.
306 */
307 else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) &&
308 (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_swidth)))
309 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth);
310 /*
311 * Roundup the allocation request to a stripe unit (m_dalign) boundary
312 * if the file size is >= stripe unit size, and we are allocating past
313 * the allocation eof.
314 */
315 else if (mp->m_dalign && (ip->i_size >= XFS_FSB_TO_B(mp, mp->m_dalign)))
316 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign);
317
318 /*
319 * Always round up the allocation request to an extent boundary
320 * (when file on a real-time subvolume or has di_extsize hint).
321 */
322 if (extsize) {
323 if (new_last_fsb)
324 align = roundup_64(new_last_fsb, extsize);
325 else
326 align = extsize;
327 new_last_fsb = roundup_64(*last_fsb, align);
328 }
329
330 if (new_last_fsb) {
331 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
332 if (error)
333 return error;
334 if (eof)
335 *last_fsb = new_last_fsb;
336 }
337 return 0;
338 }
339
340 STATIC int
341 xfs_cmn_err_fsblock_zero(
342 xfs_inode_t *ip,
343 xfs_bmbt_irec_t *imap)
344 {
345 xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount,
346 "Access to block zero in inode %llu "
347 "start_block: %llx start_off: %llx "
348 "blkcnt: %llx extent-state: %x\n",
349 (unsigned long long)ip->i_ino,
350 (unsigned long long)imap->br_startblock,
351 (unsigned long long)imap->br_startoff,
352 (unsigned long long)imap->br_blockcount,
353 imap->br_state);
354 return EFSCORRUPTED;
355 }
356
357 int
358 xfs_iomap_write_direct(
359 xfs_inode_t *ip,
360 xfs_off_t offset,
361 size_t count,
362 int flags,
363 xfs_bmbt_irec_t *ret_imap,
364 int *nmaps,
365 int found)
366 {
367 xfs_mount_t *mp = ip->i_mount;
368 xfs_fileoff_t offset_fsb;
369 xfs_fileoff_t last_fsb;
370 xfs_filblks_t count_fsb, resaligned;
371 xfs_fsblock_t firstfsb;
372 xfs_extlen_t extsz, temp;
373 int nimaps;
374 int bmapi_flag;
375 int quota_flag;
376 int rt;
377 xfs_trans_t *tp;
378 xfs_bmbt_irec_t imap;
379 xfs_bmap_free_t free_list;
380 uint qblocks, resblks, resrtextents;
381 int committed;
382 int error;
383
384 /*
385 * Make sure that the dquots are there. This doesn't hold
386 * the ilock across a disk read.
387 */
388 error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
389 if (error)
390 return XFS_ERROR(error);
391
392 rt = XFS_IS_REALTIME_INODE(ip);
393 extsz = xfs_get_extsz_hint(ip);
394
395 offset_fsb = XFS_B_TO_FSBT(mp, offset);
396 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
397 if ((offset + count) > ip->i_size) {
398 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
399 if (error)
400 goto error_out;
401 } else {
402 if (found && (ret_imap->br_startblock == HOLESTARTBLOCK))
403 last_fsb = MIN(last_fsb, (xfs_fileoff_t)
404 ret_imap->br_blockcount +
405 ret_imap->br_startoff);
406 }
407 count_fsb = last_fsb - offset_fsb;
408 ASSERT(count_fsb > 0);
409
410 resaligned = count_fsb;
411 if (unlikely(extsz)) {
412 if ((temp = do_mod(offset_fsb, extsz)))
413 resaligned += temp;
414 if ((temp = do_mod(resaligned, extsz)))
415 resaligned += extsz - temp;
416 }
417
418 if (unlikely(rt)) {
419 resrtextents = qblocks = resaligned;
420 resrtextents /= mp->m_sb.sb_rextsize;
421 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
422 quota_flag = XFS_QMOPT_RES_RTBLKS;
423 } else {
424 resrtextents = 0;
425 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
426 quota_flag = XFS_QMOPT_RES_REGBLKS;
427 }
428
429 /*
430 * Allocate and setup the transaction
431 */
432 xfs_iunlock(ip, XFS_ILOCK_EXCL);
433 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
434 error = xfs_trans_reserve(tp, resblks,
435 XFS_WRITE_LOG_RES(mp), resrtextents,
436 XFS_TRANS_PERM_LOG_RES,
437 XFS_WRITE_LOG_COUNT);
438 /*
439 * Check for running out of space, note: need lock to return
440 */
441 if (error)
442 xfs_trans_cancel(tp, 0);
443 xfs_ilock(ip, XFS_ILOCK_EXCL);
444 if (error)
445 goto error_out;
446
447 error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip,
448 qblocks, 0, quota_flag);
449 if (error)
450 goto error1;
451
452 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
453 xfs_trans_ihold(tp, ip);
454
455 bmapi_flag = XFS_BMAPI_WRITE;
456 if ((flags & BMAPI_DIRECT) && (offset < ip->i_size || extsz))
457 bmapi_flag |= XFS_BMAPI_PREALLOC;
458
459 /*
460 * Issue the xfs_bmapi() call to allocate the blocks
461 */
462 xfs_bmap_init(&free_list, &firstfsb);
463 nimaps = 1;
464 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, bmapi_flag,
465 &firstfsb, 0, &imap, &nimaps, &free_list, NULL);
466 if (error)
467 goto error0;
468
469 /*
470 * Complete the transaction
471 */
472 error = xfs_bmap_finish(&tp, &free_list, &committed);
473 if (error)
474 goto error0;
475 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
476 if (error)
477 goto error_out;
478
479 /*
480 * Copy any maps to caller's array and return any error.
481 */
482 if (nimaps == 0) {
483 error = ENOSPC;
484 goto error_out;
485 }
486
487 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) {
488 error = xfs_cmn_err_fsblock_zero(ip, &imap);
489 goto error_out;
490 }
491
492 *ret_imap = imap;
493 *nmaps = 1;
494 return 0;
495
496 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
497 xfs_bmap_cancel(&free_list);
498 XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
499
500 error1: /* Just cancel transaction */
501 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
502 *nmaps = 0; /* nothing set-up here */
503
504 error_out:
505 return XFS_ERROR(error);
506 }
507
508 /*
509 * If the caller is doing a write at the end of the file, then extend the
510 * allocation out to the file system's write iosize. We clean up any extra
511 * space left over when the file is closed in xfs_inactive().
512 */
513 STATIC int
514 xfs_iomap_eof_want_preallocate(
515 xfs_mount_t *mp,
516 xfs_inode_t *ip,
517 xfs_off_t offset,
518 size_t count,
519 int ioflag,
520 xfs_bmbt_irec_t *imap,
521 int nimaps,
522 int *prealloc)
523 {
524 xfs_fileoff_t start_fsb;
525 xfs_filblks_t count_fsb;
526 xfs_fsblock_t firstblock;
527 int n, error, imaps;
528
529 *prealloc = 0;
530 if ((offset + count) <= ip->i_size)
531 return 0;
532
533 /*
534 * If there are any real blocks past eof, then don't
535 * do any speculative allocation.
536 */
537 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
538 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
539 while (count_fsb > 0) {
540 imaps = nimaps;
541 firstblock = NULLFSBLOCK;
542 error = xfs_bmapi(NULL, ip, start_fsb, count_fsb, 0,
543 &firstblock, 0, imap, &imaps, NULL, NULL);
544 if (error)
545 return error;
546 for (n = 0; n < imaps; n++) {
547 if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
548 (imap[n].br_startblock != DELAYSTARTBLOCK))
549 return 0;
550 start_fsb += imap[n].br_blockcount;
551 count_fsb -= imap[n].br_blockcount;
552 }
553 }
554 *prealloc = 1;
555 return 0;
556 }
557
558 int
559 xfs_iomap_write_delay(
560 xfs_inode_t *ip,
561 xfs_off_t offset,
562 size_t count,
563 int ioflag,
564 xfs_bmbt_irec_t *ret_imap,
565 int *nmaps)
566 {
567 xfs_mount_t *mp = ip->i_mount;
568 xfs_fileoff_t offset_fsb;
569 xfs_fileoff_t last_fsb;
570 xfs_off_t aligned_offset;
571 xfs_fileoff_t ioalign;
572 xfs_fsblock_t firstblock;
573 xfs_extlen_t extsz;
574 int nimaps;
575 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
576 int prealloc, flushed = 0;
577 int error;
578
579 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
580
581 /*
582 * Make sure that the dquots are there. This doesn't hold
583 * the ilock across a disk read.
584 */
585 error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
586 if (error)
587 return XFS_ERROR(error);
588
589 extsz = xfs_get_extsz_hint(ip);
590 offset_fsb = XFS_B_TO_FSBT(mp, offset);
591
592 error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count,
593 ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
594 if (error)
595 return error;
596
597 retry:
598 if (prealloc) {
599 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
600 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
601 last_fsb = ioalign + mp->m_writeio_blocks;
602 } else {
603 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
604 }
605
606 if (prealloc || extsz) {
607 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
608 if (error)
609 return error;
610 }
611
612 nimaps = XFS_WRITE_IMAPS;
613 firstblock = NULLFSBLOCK;
614 error = xfs_bmapi(NULL, ip, offset_fsb,
615 (xfs_filblks_t)(last_fsb - offset_fsb),
616 XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
617 XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
618 &nimaps, NULL, NULL);
619 if (error && (error != ENOSPC))
620 return XFS_ERROR(error);
621
622 /*
623 * If bmapi returned us nothing, and if we didn't get back EDQUOT,
624 * then we must have run out of space - flush all other inodes with
625 * delalloc blocks and retry without EOF preallocation.
626 */
627 if (nimaps == 0) {
628 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
629 ip, offset, count);
630 if (flushed)
631 return XFS_ERROR(ENOSPC);
632
633 xfs_iunlock(ip, XFS_ILOCK_EXCL);
634 xfs_flush_inodes(ip);
635 xfs_ilock(ip, XFS_ILOCK_EXCL);
636
637 flushed = 1;
638 error = 0;
639 prealloc = 0;
640 goto retry;
641 }
642
643 if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip)))
644 return xfs_cmn_err_fsblock_zero(ip, &imap[0]);
645
646 *ret_imap = imap[0];
647 *nmaps = 1;
648
649 return 0;
650 }
651
652 /*
653 * Pass in a delayed allocate extent, convert it to real extents;
654 * return to the caller the extent we create which maps on top of
655 * the originating callers request.
656 *
657 * Called without a lock on the inode.
658 *
659 * We no longer bother to look at the incoming map - all we have to
660 * guarantee is that whatever we allocate fills the required range.
661 */
662 int
663 xfs_iomap_write_allocate(
664 xfs_inode_t *ip,
665 xfs_off_t offset,
666 size_t count,
667 xfs_bmbt_irec_t *map,
668 int *retmap)
669 {
670 xfs_mount_t *mp = ip->i_mount;
671 xfs_fileoff_t offset_fsb, last_block;
672 xfs_fileoff_t end_fsb, map_start_fsb;
673 xfs_fsblock_t first_block;
674 xfs_bmap_free_t free_list;
675 xfs_filblks_t count_fsb;
676 xfs_bmbt_irec_t imap;
677 xfs_trans_t *tp;
678 int nimaps, committed;
679 int error = 0;
680 int nres;
681
682 *retmap = 0;
683
684 /*
685 * Make sure that the dquots are there.
686 */
687 if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
688 return XFS_ERROR(error);
689
690 offset_fsb = XFS_B_TO_FSBT(mp, offset);
691 count_fsb = map->br_blockcount;
692 map_start_fsb = map->br_startoff;
693
694 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
695
696 while (count_fsb != 0) {
697 /*
698 * Set up a transaction with which to allocate the
699 * backing store for the file. Do allocations in a
700 * loop until we get some space in the range we are
701 * interested in. The other space that might be allocated
702 * is in the delayed allocation extent on which we sit
703 * but before our buffer starts.
704 */
705
706 nimaps = 0;
707 while (nimaps == 0) {
708 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
709 tp->t_flags |= XFS_TRANS_RESERVE;
710 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
711 error = xfs_trans_reserve(tp, nres,
712 XFS_WRITE_LOG_RES(mp),
713 0, XFS_TRANS_PERM_LOG_RES,
714 XFS_WRITE_LOG_COUNT);
715 if (error) {
716 xfs_trans_cancel(tp, 0);
717 return XFS_ERROR(error);
718 }
719 xfs_ilock(ip, XFS_ILOCK_EXCL);
720 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
721 xfs_trans_ihold(tp, ip);
722
723 xfs_bmap_init(&free_list, &first_block);
724
725 /*
726 * it is possible that the extents have changed since
727 * we did the read call as we dropped the ilock for a
728 * while. We have to be careful about truncates or hole
729 * punchs here - we are not allowed to allocate
730 * non-delalloc blocks here.
731 *
732 * The only protection against truncation is the pages
733 * for the range we are being asked to convert are
734 * locked and hence a truncate will block on them
735 * first.
736 *
737 * As a result, if we go beyond the range we really
738 * need and hit an delalloc extent boundary followed by
739 * a hole while we have excess blocks in the map, we
740 * will fill the hole incorrectly and overrun the
741 * transaction reservation.
742 *
743 * Using a single map prevents this as we are forced to
744 * check each map we look for overlap with the desired
745 * range and abort as soon as we find it. Also, given
746 * that we only return a single map, having one beyond
747 * what we can return is probably a bit silly.
748 *
749 * We also need to check that we don't go beyond EOF;
750 * this is a truncate optimisation as a truncate sets
751 * the new file size before block on the pages we
752 * currently have locked under writeback. Because they
753 * are about to be tossed, we don't need to write them
754 * back....
755 */
756 nimaps = 1;
757 end_fsb = XFS_B_TO_FSB(mp, ip->i_size);
758 error = xfs_bmap_last_offset(NULL, ip, &last_block,
759 XFS_DATA_FORK);
760 if (error)
761 goto trans_cancel;
762
763 last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
764 if ((map_start_fsb + count_fsb) > last_block) {
765 count_fsb = last_block - map_start_fsb;
766 if (count_fsb == 0) {
767 error = EAGAIN;
768 goto trans_cancel;
769 }
770 }
771
772 /* Go get the actual blocks */
773 error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
774 XFS_BMAPI_WRITE, &first_block, 1,
775 &imap, &nimaps, &free_list, NULL);
776 if (error)
777 goto trans_cancel;
778
779 error = xfs_bmap_finish(&tp, &free_list, &committed);
780 if (error)
781 goto trans_cancel;
782
783 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
784 if (error)
785 goto error0;
786
787 xfs_iunlock(ip, XFS_ILOCK_EXCL);
788 }
789
790 /*
791 * See if we were able to allocate an extent that
792 * covers at least part of the callers request
793 */
794 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
795 return xfs_cmn_err_fsblock_zero(ip, &imap);
796
797 if ((offset_fsb >= imap.br_startoff) &&
798 (offset_fsb < (imap.br_startoff +
799 imap.br_blockcount))) {
800 *map = imap;
801 *retmap = 1;
802 XFS_STATS_INC(xs_xstrat_quick);
803 return 0;
804 }
805
806 /*
807 * So far we have not mapped the requested part of the
808 * file, just surrounding data, try again.
809 */
810 count_fsb -= imap.br_blockcount;
811 map_start_fsb = imap.br_startoff + imap.br_blockcount;
812 }
813
814 trans_cancel:
815 xfs_bmap_cancel(&free_list);
816 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
817 error0:
818 xfs_iunlock(ip, XFS_ILOCK_EXCL);
819 return XFS_ERROR(error);
820 }
821
822 int
823 xfs_iomap_write_unwritten(
824 xfs_inode_t *ip,
825 xfs_off_t offset,
826 size_t count)
827 {
828 xfs_mount_t *mp = ip->i_mount;
829 xfs_fileoff_t offset_fsb;
830 xfs_filblks_t count_fsb;
831 xfs_filblks_t numblks_fsb;
832 xfs_fsblock_t firstfsb;
833 int nimaps;
834 xfs_trans_t *tp;
835 xfs_bmbt_irec_t imap;
836 xfs_bmap_free_t free_list;
837 uint resblks;
838 int committed;
839 int error;
840
841 xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN, ip, offset, count);
842
843 offset_fsb = XFS_B_TO_FSBT(mp, offset);
844 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
845 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
846
847 /*
848 * Reserve enough blocks in this transaction for two complete extent
849 * btree splits. We may be converting the middle part of an unwritten
850 * extent and in this case we will insert two new extents in the btree
851 * each of which could cause a full split.
852 *
853 * This reservation amount will be used in the first call to
854 * xfs_bmbt_split() to select an AG with enough space to satisfy the
855 * rest of the operation.
856 */
857 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
858
859 do {
860 /*
861 * set up a transaction to convert the range of extents
862 * from unwritten to real. Do allocations in a loop until
863 * we have covered the range passed in.
864 */
865 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
866 tp->t_flags |= XFS_TRANS_RESERVE;
867 error = xfs_trans_reserve(tp, resblks,
868 XFS_WRITE_LOG_RES(mp), 0,
869 XFS_TRANS_PERM_LOG_RES,
870 XFS_WRITE_LOG_COUNT);
871 if (error) {
872 xfs_trans_cancel(tp, 0);
873 return XFS_ERROR(error);
874 }
875
876 xfs_ilock(ip, XFS_ILOCK_EXCL);
877 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
878 xfs_trans_ihold(tp, ip);
879
880 /*
881 * Modify the unwritten extent state of the buffer.
882 */
883 xfs_bmap_init(&free_list, &firstfsb);
884 nimaps = 1;
885 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
886 XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb,
887 1, &imap, &nimaps, &free_list, NULL);
888 if (error)
889 goto error_on_bmapi_transaction;
890
891 error = xfs_bmap_finish(&(tp), &(free_list), &committed);
892 if (error)
893 goto error_on_bmapi_transaction;
894
895 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
896 xfs_iunlock(ip, XFS_ILOCK_EXCL);
897 if (error)
898 return XFS_ERROR(error);
899
900 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
901 return xfs_cmn_err_fsblock_zero(ip, &imap);
902
903 if ((numblks_fsb = imap.br_blockcount) == 0) {
904 /*
905 * The numblks_fsb value should always get
906 * smaller, otherwise the loop is stuck.
907 */
908 ASSERT(imap.br_blockcount);
909 break;
910 }
911 offset_fsb += numblks_fsb;
912 count_fsb -= numblks_fsb;
913 } while (count_fsb > 0);
914
915 return 0;
916
917 error_on_bmapi_transaction:
918 xfs_bmap_cancel(&free_list);
919 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
920 xfs_iunlock(ip, XFS_ILOCK_EXCL);
921 return XFS_ERROR(error);
922 }
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