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