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Merge branch 'x86/uaccess' into core/percpu
[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_flush_space(
342 xfs_inode_t *ip,
343 int *fsynced,
344 int *ioflags)
345 {
346 switch (*fsynced) {
347 case 0:
348 if (ip->i_delayed_blks) {
349 xfs_iunlock(ip, XFS_ILOCK_EXCL);
350 xfs_flush_inode(ip);
351 xfs_ilock(ip, XFS_ILOCK_EXCL);
352 *fsynced = 1;
353 } else {
354 *ioflags |= BMAPI_SYNC;
355 *fsynced = 2;
356 }
357 return 0;
358 case 1:
359 *fsynced = 2;
360 *ioflags |= BMAPI_SYNC;
361 return 0;
362 case 2:
363 xfs_iunlock(ip, XFS_ILOCK_EXCL);
364 xfs_flush_device(ip);
365 xfs_ilock(ip, XFS_ILOCK_EXCL);
366 *fsynced = 3;
367 return 0;
368 }
369 return 1;
370 }
371
372 STATIC int
373 xfs_cmn_err_fsblock_zero(
374 xfs_inode_t *ip,
375 xfs_bmbt_irec_t *imap)
376 {
377 xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount,
378 "Access to block zero in inode %llu "
379 "start_block: %llx start_off: %llx "
380 "blkcnt: %llx extent-state: %x\n",
381 (unsigned long long)ip->i_ino,
382 (unsigned long long)imap->br_startblock,
383 (unsigned long long)imap->br_startoff,
384 (unsigned long long)imap->br_blockcount,
385 imap->br_state);
386 return EFSCORRUPTED;
387 }
388
389 int
390 xfs_iomap_write_direct(
391 xfs_inode_t *ip,
392 xfs_off_t offset,
393 size_t count,
394 int flags,
395 xfs_bmbt_irec_t *ret_imap,
396 int *nmaps,
397 int found)
398 {
399 xfs_mount_t *mp = ip->i_mount;
400 xfs_fileoff_t offset_fsb;
401 xfs_fileoff_t last_fsb;
402 xfs_filblks_t count_fsb, resaligned;
403 xfs_fsblock_t firstfsb;
404 xfs_extlen_t extsz, temp;
405 int nimaps;
406 int bmapi_flag;
407 int quota_flag;
408 int rt;
409 xfs_trans_t *tp;
410 xfs_bmbt_irec_t imap;
411 xfs_bmap_free_t free_list;
412 uint qblocks, resblks, resrtextents;
413 int committed;
414 int error;
415
416 /*
417 * Make sure that the dquots are there. This doesn't hold
418 * the ilock across a disk read.
419 */
420 error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
421 if (error)
422 return XFS_ERROR(error);
423
424 rt = XFS_IS_REALTIME_INODE(ip);
425 extsz = xfs_get_extsz_hint(ip);
426
427 offset_fsb = XFS_B_TO_FSBT(mp, offset);
428 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
429 if ((offset + count) > ip->i_size) {
430 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
431 if (error)
432 goto error_out;
433 } else {
434 if (found && (ret_imap->br_startblock == HOLESTARTBLOCK))
435 last_fsb = MIN(last_fsb, (xfs_fileoff_t)
436 ret_imap->br_blockcount +
437 ret_imap->br_startoff);
438 }
439 count_fsb = last_fsb - offset_fsb;
440 ASSERT(count_fsb > 0);
441
442 resaligned = count_fsb;
443 if (unlikely(extsz)) {
444 if ((temp = do_mod(offset_fsb, extsz)))
445 resaligned += temp;
446 if ((temp = do_mod(resaligned, extsz)))
447 resaligned += extsz - temp;
448 }
449
450 if (unlikely(rt)) {
451 resrtextents = qblocks = resaligned;
452 resrtextents /= mp->m_sb.sb_rextsize;
453 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
454 quota_flag = XFS_QMOPT_RES_RTBLKS;
455 } else {
456 resrtextents = 0;
457 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
458 quota_flag = XFS_QMOPT_RES_REGBLKS;
459 }
460
461 /*
462 * Allocate and setup the transaction
463 */
464 xfs_iunlock(ip, XFS_ILOCK_EXCL);
465 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
466 error = xfs_trans_reserve(tp, resblks,
467 XFS_WRITE_LOG_RES(mp), resrtextents,
468 XFS_TRANS_PERM_LOG_RES,
469 XFS_WRITE_LOG_COUNT);
470 /*
471 * Check for running out of space, note: need lock to return
472 */
473 if (error)
474 xfs_trans_cancel(tp, 0);
475 xfs_ilock(ip, XFS_ILOCK_EXCL);
476 if (error)
477 goto error_out;
478
479 error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip,
480 qblocks, 0, quota_flag);
481 if (error)
482 goto error1;
483
484 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
485 xfs_trans_ihold(tp, ip);
486
487 bmapi_flag = XFS_BMAPI_WRITE;
488 if ((flags & BMAPI_DIRECT) && (offset < ip->i_size || extsz))
489 bmapi_flag |= XFS_BMAPI_PREALLOC;
490
491 /*
492 * Issue the xfs_bmapi() call to allocate the blocks
493 */
494 xfs_bmap_init(&free_list, &firstfsb);
495 nimaps = 1;
496 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb, bmapi_flag,
497 &firstfsb, 0, &imap, &nimaps, &free_list, NULL);
498 if (error)
499 goto error0;
500
501 /*
502 * Complete the transaction
503 */
504 error = xfs_bmap_finish(&tp, &free_list, &committed);
505 if (error)
506 goto error0;
507 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
508 if (error)
509 goto error_out;
510
511 /*
512 * Copy any maps to caller's array and return any error.
513 */
514 if (nimaps == 0) {
515 error = ENOSPC;
516 goto error_out;
517 }
518
519 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) {
520 error = xfs_cmn_err_fsblock_zero(ip, &imap);
521 goto error_out;
522 }
523
524 *ret_imap = imap;
525 *nmaps = 1;
526 return 0;
527
528 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
529 xfs_bmap_cancel(&free_list);
530 XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
531
532 error1: /* Just cancel transaction */
533 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
534 *nmaps = 0; /* nothing set-up here */
535
536 error_out:
537 return XFS_ERROR(error);
538 }
539
540 /*
541 * If the caller is doing a write at the end of the file,
542 * then extend the allocation out to the file system's write
543 * iosize. We clean up any extra space left over when the
544 * file is closed in xfs_inactive().
545 *
546 * For sync writes, we are flushing delayed allocate space to
547 * try to make additional space available for allocation near
548 * the filesystem full boundary - preallocation hurts in that
549 * situation, of course.
550 */
551 STATIC int
552 xfs_iomap_eof_want_preallocate(
553 xfs_mount_t *mp,
554 xfs_inode_t *ip,
555 xfs_off_t offset,
556 size_t count,
557 int ioflag,
558 xfs_bmbt_irec_t *imap,
559 int nimaps,
560 int *prealloc)
561 {
562 xfs_fileoff_t start_fsb;
563 xfs_filblks_t count_fsb;
564 xfs_fsblock_t firstblock;
565 int n, error, imaps;
566
567 *prealloc = 0;
568 if ((ioflag & BMAPI_SYNC) || (offset + count) <= ip->i_size)
569 return 0;
570
571 /*
572 * If there are any real blocks past eof, then don't
573 * do any speculative allocation.
574 */
575 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
576 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
577 while (count_fsb > 0) {
578 imaps = nimaps;
579 firstblock = NULLFSBLOCK;
580 error = xfs_bmapi(NULL, ip, start_fsb, count_fsb, 0,
581 &firstblock, 0, imap, &imaps, NULL, NULL);
582 if (error)
583 return error;
584 for (n = 0; n < imaps; n++) {
585 if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
586 (imap[n].br_startblock != DELAYSTARTBLOCK))
587 return 0;
588 start_fsb += imap[n].br_blockcount;
589 count_fsb -= imap[n].br_blockcount;
590 }
591 }
592 *prealloc = 1;
593 return 0;
594 }
595
596 int
597 xfs_iomap_write_delay(
598 xfs_inode_t *ip,
599 xfs_off_t offset,
600 size_t count,
601 int ioflag,
602 xfs_bmbt_irec_t *ret_imap,
603 int *nmaps)
604 {
605 xfs_mount_t *mp = ip->i_mount;
606 xfs_fileoff_t offset_fsb;
607 xfs_fileoff_t last_fsb;
608 xfs_off_t aligned_offset;
609 xfs_fileoff_t ioalign;
610 xfs_fsblock_t firstblock;
611 xfs_extlen_t extsz;
612 int nimaps;
613 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
614 int prealloc, fsynced = 0;
615 int error;
616
617 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
618
619 /*
620 * Make sure that the dquots are there. This doesn't hold
621 * the ilock across a disk read.
622 */
623 error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
624 if (error)
625 return XFS_ERROR(error);
626
627 extsz = xfs_get_extsz_hint(ip);
628 offset_fsb = XFS_B_TO_FSBT(mp, offset);
629
630 retry:
631 error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count,
632 ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
633 if (error)
634 return error;
635
636 if (prealloc) {
637 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
638 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
639 last_fsb = ioalign + mp->m_writeio_blocks;
640 } else {
641 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
642 }
643
644 if (prealloc || extsz) {
645 error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb);
646 if (error)
647 return error;
648 }
649
650 nimaps = XFS_WRITE_IMAPS;
651 firstblock = NULLFSBLOCK;
652 error = xfs_bmapi(NULL, ip, offset_fsb,
653 (xfs_filblks_t)(last_fsb - offset_fsb),
654 XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
655 XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
656 &nimaps, NULL, NULL);
657 if (error && (error != ENOSPC))
658 return XFS_ERROR(error);
659
660 /*
661 * If bmapi returned us nothing, and if we didn't get back EDQUOT,
662 * then we must have run out of space - flush delalloc, and retry..
663 */
664 if (nimaps == 0) {
665 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
666 ip, offset, count);
667 if (xfs_flush_space(ip, &fsynced, &ioflag))
668 return XFS_ERROR(ENOSPC);
669
670 error = 0;
671 goto retry;
672 }
673
674 if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip)))
675 return xfs_cmn_err_fsblock_zero(ip, &imap[0]);
676
677 *ret_imap = imap[0];
678 *nmaps = 1;
679
680 return 0;
681 }
682
683 /*
684 * Pass in a delayed allocate extent, convert it to real extents;
685 * return to the caller the extent we create which maps on top of
686 * the originating callers request.
687 *
688 * Called without a lock on the inode.
689 *
690 * We no longer bother to look at the incoming map - all we have to
691 * guarantee is that whatever we allocate fills the required range.
692 */
693 int
694 xfs_iomap_write_allocate(
695 xfs_inode_t *ip,
696 xfs_off_t offset,
697 size_t count,
698 xfs_bmbt_irec_t *map,
699 int *retmap)
700 {
701 xfs_mount_t *mp = ip->i_mount;
702 xfs_fileoff_t offset_fsb, last_block;
703 xfs_fileoff_t end_fsb, map_start_fsb;
704 xfs_fsblock_t first_block;
705 xfs_bmap_free_t free_list;
706 xfs_filblks_t count_fsb;
707 xfs_bmbt_irec_t imap;
708 xfs_trans_t *tp;
709 int nimaps, committed;
710 int error = 0;
711 int nres;
712
713 *retmap = 0;
714
715 /*
716 * Make sure that the dquots are there.
717 */
718 if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
719 return XFS_ERROR(error);
720
721 offset_fsb = XFS_B_TO_FSBT(mp, offset);
722 count_fsb = map->br_blockcount;
723 map_start_fsb = map->br_startoff;
724
725 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
726
727 while (count_fsb != 0) {
728 /*
729 * Set up a transaction with which to allocate the
730 * backing store for the file. Do allocations in a
731 * loop until we get some space in the range we are
732 * interested in. The other space that might be allocated
733 * is in the delayed allocation extent on which we sit
734 * but before our buffer starts.
735 */
736
737 nimaps = 0;
738 while (nimaps == 0) {
739 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
740 tp->t_flags |= XFS_TRANS_RESERVE;
741 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
742 error = xfs_trans_reserve(tp, nres,
743 XFS_WRITE_LOG_RES(mp),
744 0, XFS_TRANS_PERM_LOG_RES,
745 XFS_WRITE_LOG_COUNT);
746 if (error) {
747 xfs_trans_cancel(tp, 0);
748 return XFS_ERROR(error);
749 }
750 xfs_ilock(ip, XFS_ILOCK_EXCL);
751 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
752 xfs_trans_ihold(tp, ip);
753
754 xfs_bmap_init(&free_list, &first_block);
755
756 /*
757 * it is possible that the extents have changed since
758 * we did the read call as we dropped the ilock for a
759 * while. We have to be careful about truncates or hole
760 * punchs here - we are not allowed to allocate
761 * non-delalloc blocks here.
762 *
763 * The only protection against truncation is the pages
764 * for the range we are being asked to convert are
765 * locked and hence a truncate will block on them
766 * first.
767 *
768 * As a result, if we go beyond the range we really
769 * need and hit an delalloc extent boundary followed by
770 * a hole while we have excess blocks in the map, we
771 * will fill the hole incorrectly and overrun the
772 * transaction reservation.
773 *
774 * Using a single map prevents this as we are forced to
775 * check each map we look for overlap with the desired
776 * range and abort as soon as we find it. Also, given
777 * that we only return a single map, having one beyond
778 * what we can return is probably a bit silly.
779 *
780 * We also need to check that we don't go beyond EOF;
781 * this is a truncate optimisation as a truncate sets
782 * the new file size before block on the pages we
783 * currently have locked under writeback. Because they
784 * are about to be tossed, we don't need to write them
785 * back....
786 */
787 nimaps = 1;
788 end_fsb = XFS_B_TO_FSB(mp, ip->i_size);
789 error = xfs_bmap_last_offset(NULL, ip, &last_block,
790 XFS_DATA_FORK);
791 if (error)
792 goto trans_cancel;
793
794 last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
795 if ((map_start_fsb + count_fsb) > last_block) {
796 count_fsb = last_block - map_start_fsb;
797 if (count_fsb == 0) {
798 error = EAGAIN;
799 goto trans_cancel;
800 }
801 }
802
803 /* Go get the actual blocks */
804 error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
805 XFS_BMAPI_WRITE, &first_block, 1,
806 &imap, &nimaps, &free_list, NULL);
807 if (error)
808 goto trans_cancel;
809
810 error = xfs_bmap_finish(&tp, &free_list, &committed);
811 if (error)
812 goto trans_cancel;
813
814 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
815 if (error)
816 goto error0;
817
818 xfs_iunlock(ip, XFS_ILOCK_EXCL);
819 }
820
821 /*
822 * See if we were able to allocate an extent that
823 * covers at least part of the callers request
824 */
825 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
826 return xfs_cmn_err_fsblock_zero(ip, &imap);
827
828 if ((offset_fsb >= imap.br_startoff) &&
829 (offset_fsb < (imap.br_startoff +
830 imap.br_blockcount))) {
831 *map = imap;
832 *retmap = 1;
833 XFS_STATS_INC(xs_xstrat_quick);
834 return 0;
835 }
836
837 /*
838 * So far we have not mapped the requested part of the
839 * file, just surrounding data, try again.
840 */
841 count_fsb -= imap.br_blockcount;
842 map_start_fsb = imap.br_startoff + imap.br_blockcount;
843 }
844
845 trans_cancel:
846 xfs_bmap_cancel(&free_list);
847 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
848 error0:
849 xfs_iunlock(ip, XFS_ILOCK_EXCL);
850 return XFS_ERROR(error);
851 }
852
853 int
854 xfs_iomap_write_unwritten(
855 xfs_inode_t *ip,
856 xfs_off_t offset,
857 size_t count)
858 {
859 xfs_mount_t *mp = ip->i_mount;
860 xfs_fileoff_t offset_fsb;
861 xfs_filblks_t count_fsb;
862 xfs_filblks_t numblks_fsb;
863 xfs_fsblock_t firstfsb;
864 int nimaps;
865 xfs_trans_t *tp;
866 xfs_bmbt_irec_t imap;
867 xfs_bmap_free_t free_list;
868 uint resblks;
869 int committed;
870 int error;
871
872 xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN, ip, offset, count);
873
874 offset_fsb = XFS_B_TO_FSBT(mp, offset);
875 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
876 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
877
878 /*
879 * Reserve enough blocks in this transaction for two complete extent
880 * btree splits. We may be converting the middle part of an unwritten
881 * extent and in this case we will insert two new extents in the btree
882 * each of which could cause a full split.
883 *
884 * This reservation amount will be used in the first call to
885 * xfs_bmbt_split() to select an AG with enough space to satisfy the
886 * rest of the operation.
887 */
888 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
889
890 do {
891 /*
892 * set up a transaction to convert the range of extents
893 * from unwritten to real. Do allocations in a loop until
894 * we have covered the range passed in.
895 */
896 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
897 tp->t_flags |= XFS_TRANS_RESERVE;
898 error = xfs_trans_reserve(tp, resblks,
899 XFS_WRITE_LOG_RES(mp), 0,
900 XFS_TRANS_PERM_LOG_RES,
901 XFS_WRITE_LOG_COUNT);
902 if (error) {
903 xfs_trans_cancel(tp, 0);
904 return XFS_ERROR(error);
905 }
906
907 xfs_ilock(ip, XFS_ILOCK_EXCL);
908 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
909 xfs_trans_ihold(tp, ip);
910
911 /*
912 * Modify the unwritten extent state of the buffer.
913 */
914 xfs_bmap_init(&free_list, &firstfsb);
915 nimaps = 1;
916 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
917 XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb,
918 1, &imap, &nimaps, &free_list, NULL);
919 if (error)
920 goto error_on_bmapi_transaction;
921
922 error = xfs_bmap_finish(&(tp), &(free_list), &committed);
923 if (error)
924 goto error_on_bmapi_transaction;
925
926 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
927 xfs_iunlock(ip, XFS_ILOCK_EXCL);
928 if (error)
929 return XFS_ERROR(error);
930
931 if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
932 return xfs_cmn_err_fsblock_zero(ip, &imap);
933
934 if ((numblks_fsb = imap.br_blockcount) == 0) {
935 /*
936 * The numblks_fsb value should always get
937 * smaller, otherwise the loop is stuck.
938 */
939 ASSERT(imap.br_blockcount);
940 break;
941 }
942 offset_fsb += numblks_fsb;
943 count_fsb -= numblks_fsb;
944 } while (count_fsb > 0);
945
946 return 0;
947
948 error_on_bmapi_transaction:
949 xfs_bmap_cancel(&free_list);
950 xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
951 xfs_iunlock(ip, XFS_ILOCK_EXCL);
952 return XFS_ERROR(error);
953 }
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