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cfq-iosched: make checkpatch compliant
[linux-2.6/pdupreez.git] / fs / xfs / xfs_iomap.c
blob72786e356d56ebba6e1f6455cf9f471fd52745fa
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_iocore_t *io,
57 xfs_off_t offset,
58 ssize_t count)
59 {
60 xfs_inode_t *ip = XFS_IO_INODE(io);
61
62 if (!ip->i_rwtrace)
63 return;
64
65 ktrace_enter(ip->i_rwtrace,
66 (void *)((unsigned long)tag),
67 (void *)ip,
68 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
69 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
70 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
71 (void *)((unsigned long)(offset & 0xffffffff)),
72 (void *)((unsigned long)count),
73 (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
74 (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
75 (void *)((unsigned long)current_pid()),
76 (void *)NULL,
77 (void *)NULL,
78 (void *)NULL,
79 (void *)NULL,
80 (void *)NULL,
81 (void *)NULL);
82 }
83
84 void
85 xfs_iomap_map_trace(
86 int tag,
87 xfs_iocore_t *io,
88 xfs_off_t offset,
89 ssize_t count,
90 xfs_iomap_t *iomapp,
91 xfs_bmbt_irec_t *imapp,
92 int flags)
93 {
94 xfs_inode_t *ip = XFS_IO_INODE(io);
95
96 if (!ip->i_rwtrace)
97 return;
98
99 ktrace_enter(ip->i_rwtrace,
100 (void *)((unsigned long)tag),
101 (void *)ip,
102 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
103 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
104 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
105 (void *)((unsigned long)(offset & 0xffffffff)),
106 (void *)((unsigned long)count),
107 (void *)((unsigned long)flags),
108 (void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)),
109 (void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)),
110 (void *)((unsigned long)(iomapp->iomap_delta)),
111 (void *)((unsigned long)(iomapp->iomap_bsize)),
112 (void *)((unsigned long)(iomapp->iomap_bn)),
113 (void *)(__psint_t)(imapp->br_startoff),
114 (void *)((unsigned long)(imapp->br_blockcount)),
115 (void *)(__psint_t)(imapp->br_startblock));
116 }
117 #else
118 #define xfs_iomap_enter_trace(tag, io, offset, count)
119 #define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags)
120 #endif
121
122 #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
123 << mp->m_writeio_log)
124 #define XFS_STRAT_WRITE_IMAPS 2
125 #define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP
126
127 STATIC int
128 xfs_imap_to_bmap(
129 xfs_iocore_t *io,
130 xfs_off_t offset,
131 xfs_bmbt_irec_t *imap,
132 xfs_iomap_t *iomapp,
133 int imaps, /* Number of imap entries */
134 int iomaps, /* Number of iomap entries */
135 int flags)
136 {
137 xfs_mount_t *mp;
138 int pbm;
139 xfs_fsblock_t start_block;
140
141 mp = io->io_mount;
142
143 for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
144 iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
145 iomapp->iomap_delta = offset - iomapp->iomap_offset;
146 iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
147 iomapp->iomap_flags = flags;
148
149 if (io->io_flags & XFS_IOCORE_RT) {
150 iomapp->iomap_flags |= IOMAP_REALTIME;
151 iomapp->iomap_target = mp->m_rtdev_targp;
152 } else {
153 iomapp->iomap_target = mp->m_ddev_targp;
154 }
155 start_block = imap->br_startblock;
156 if (start_block == HOLESTARTBLOCK) {
157 iomapp->iomap_bn = IOMAP_DADDR_NULL;
158 iomapp->iomap_flags |= IOMAP_HOLE;
159 } else if (start_block == DELAYSTARTBLOCK) {
160 iomapp->iomap_bn = IOMAP_DADDR_NULL;
161 iomapp->iomap_flags |= IOMAP_DELAY;
162 } else {
163 iomapp->iomap_bn = XFS_FSB_TO_DB_IO(io, start_block);
164 if (ISUNWRITTEN(imap))
165 iomapp->iomap_flags |= IOMAP_UNWRITTEN;
166 }
167
168 offset += iomapp->iomap_bsize - iomapp->iomap_delta;
169 }
170 return pbm; /* Return the number filled */
171 }
172
173 int
174 xfs_iomap(
175 xfs_iocore_t *io,
176 xfs_off_t offset,
177 ssize_t count,
178 int flags,
179 xfs_iomap_t *iomapp,
180 int *niomaps)
181 {
182 xfs_mount_t *mp = io->io_mount;
183 xfs_fileoff_t offset_fsb, end_fsb;
184 int error = 0;
185 int lockmode = 0;
186 xfs_bmbt_irec_t imap;
187 int nimaps = 1;
188 int bmapi_flags = 0;
189 int iomap_flags = 0;
190
191 if (XFS_FORCED_SHUTDOWN(mp))
192 return XFS_ERROR(EIO);
193
194 switch (flags &
195 (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE |
196 BMAPI_UNWRITTEN | BMAPI_DEVICE)) {
197 case BMAPI_READ:
198 xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, io, offset, count);
199 lockmode = XFS_LCK_MAP_SHARED(mp, io);
200 bmapi_flags = XFS_BMAPI_ENTIRE;
201 break;
202 case BMAPI_WRITE:
203 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, io, offset, count);
204 lockmode = XFS_ILOCK_EXCL|XFS_EXTSIZE_WR;
205 if (flags & BMAPI_IGNSTATE)
206 bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE;
207 XFS_ILOCK(mp, io, lockmode);
208 break;
209 case BMAPI_ALLOCATE:
210 xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, io, offset, count);
211 lockmode = XFS_ILOCK_SHARED|XFS_EXTSIZE_RD;
212 bmapi_flags = XFS_BMAPI_ENTIRE;
213 /* Attempt non-blocking lock */
214 if (flags & BMAPI_TRYLOCK) {
215 if (!XFS_ILOCK_NOWAIT(mp, io, lockmode))
216 return XFS_ERROR(EAGAIN);
217 } else {
218 XFS_ILOCK(mp, io, lockmode);
219 }
220 break;
221 case BMAPI_UNWRITTEN:
222 goto phase2;
223 case BMAPI_DEVICE:
224 lockmode = XFS_LCK_MAP_SHARED(mp, io);
225 iomapp->iomap_target = io->io_flags & XFS_IOCORE_RT ?
226 mp->m_rtdev_targp : mp->m_ddev_targp;
227 error = 0;
228 *niomaps = 1;
229 goto out;
230 default:
231 BUG();
232 }
233
234 ASSERT(offset <= mp->m_maxioffset);
235 if ((xfs_fsize_t)offset + count > mp->m_maxioffset)
236 count = mp->m_maxioffset - offset;
237 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
238 offset_fsb = XFS_B_TO_FSBT(mp, offset);
239
240 error = XFS_BMAPI(mp, NULL, io, offset_fsb,
241 (xfs_filblks_t)(end_fsb - offset_fsb),
242 bmapi_flags, NULL, 0, &imap,
243 &nimaps, NULL, NULL);
244
245 if (error)
246 goto out;
247
248 phase2:
249 switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE|BMAPI_UNWRITTEN)) {
250 case BMAPI_WRITE:
251 /* If we found an extent, return it */
252 if (nimaps &&
253 (imap.br_startblock != HOLESTARTBLOCK) &&
254 (imap.br_startblock != DELAYSTARTBLOCK)) {
255 xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
256 offset, count, iomapp, &imap, flags);
257 break;
258 }
259
260 if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
261 error = XFS_IOMAP_WRITE_DIRECT(mp, io, offset,
262 count, flags, &imap, &nimaps, nimaps);
263 } else {
264 error = XFS_IOMAP_WRITE_DELAY(mp, io, offset, count,
265 flags, &imap, &nimaps);
266 }
267 if (!error) {
268 xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, io,
269 offset, count, iomapp, &imap, flags);
270 }
271 iomap_flags = IOMAP_NEW;
272 break;
273 case BMAPI_ALLOCATE:
274 /* If we found an extent, return it */
275 XFS_IUNLOCK(mp, io, lockmode);
276 lockmode = 0;
277
278 if (nimaps && !ISNULLSTARTBLOCK(imap.br_startblock)) {
279 xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
280 offset, count, iomapp, &imap, flags);
281 break;
282 }
283
284 error = XFS_IOMAP_WRITE_ALLOCATE(mp, io, offset, count,
285 &imap, &nimaps);
286 break;
287 case BMAPI_UNWRITTEN:
288 lockmode = 0;
289 error = XFS_IOMAP_WRITE_UNWRITTEN(mp, io, offset, count);
290 nimaps = 0;
291 break;
292 }
293
294 if (nimaps) {
295 *niomaps = xfs_imap_to_bmap(io, offset, &imap,
296 iomapp, nimaps, *niomaps, iomap_flags);
297 } else if (niomaps) {
298 *niomaps = 0;
299 }
300
301 out:
302 if (lockmode)
303 XFS_IUNLOCK(mp, io, lockmode);
304 return XFS_ERROR(error);
305 }
306
307 STATIC int
308 xfs_iomap_eof_align_last_fsb(
309 xfs_mount_t *mp,
310 xfs_iocore_t *io,
311 xfs_fsize_t isize,
312 xfs_extlen_t extsize,
313 xfs_fileoff_t *last_fsb)
314 {
315 xfs_fileoff_t new_last_fsb = 0;
316 xfs_extlen_t align;
317 int eof, error;
318
319 if (io->io_flags & XFS_IOCORE_RT)
320 ;
321 /*
322 * If mounted with the "-o swalloc" option, roundup the allocation
323 * request to a stripe width boundary if the file size is >=
324 * stripe width and we are allocating past the allocation eof.
325 */
326 else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) &&
327 (isize >= XFS_FSB_TO_B(mp, mp->m_swidth)))
328 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth);
329 /*
330 * Roundup the allocation request to a stripe unit (m_dalign) boundary
331 * if the file size is >= stripe unit size, and we are allocating past
332 * the allocation eof.
333 */
334 else if (mp->m_dalign && (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)))
335 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign);
336
337 /*
338 * Always round up the allocation request to an extent boundary
339 * (when file on a real-time subvolume or has di_extsize hint).
340 */
341 if (extsize) {
342 if (new_last_fsb)
343 align = roundup_64(new_last_fsb, extsize);
344 else
345 align = extsize;
346 new_last_fsb = roundup_64(*last_fsb, align);
347 }
348
349 if (new_last_fsb) {
350 error = XFS_BMAP_EOF(mp, io, new_last_fsb, XFS_DATA_FORK, &eof);
351 if (error)
352 return error;
353 if (eof)
354 *last_fsb = new_last_fsb;
355 }
356 return 0;
357 }
358
359 STATIC int
360 xfs_flush_space(
361 xfs_inode_t *ip,
362 int *fsynced,
363 int *ioflags)
364 {
365 switch (*fsynced) {
366 case 0:
367 if (ip->i_delayed_blks) {
368 xfs_iunlock(ip, XFS_ILOCK_EXCL);
369 xfs_flush_inode(ip);
370 xfs_ilock(ip, XFS_ILOCK_EXCL);
371 *fsynced = 1;
372 } else {
373 *ioflags |= BMAPI_SYNC;
374 *fsynced = 2;
375 }
376 return 0;
377 case 1:
378 *fsynced = 2;
379 *ioflags |= BMAPI_SYNC;
380 return 0;
381 case 2:
382 xfs_iunlock(ip, XFS_ILOCK_EXCL);
383 xfs_flush_device(ip);
384 xfs_ilock(ip, XFS_ILOCK_EXCL);
385 *fsynced = 3;
386 return 0;
387 }
388 return 1;
389 }
390
391 STATIC int
392 xfs_cmn_err_fsblock_zero(
393 xfs_inode_t *ip,
394 xfs_bmbt_irec_t *imap)
395 {
396 xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount,
397 "Access to block zero in inode %llu "
398 "start_block: %llx start_off: %llx "
399 "blkcnt: %llx extent-state: %x\n",
400 (unsigned long long)ip->i_ino,
401 (unsigned long long)imap->br_startblock,
402 (unsigned long long)imap->br_startoff,
403 (unsigned long long)imap->br_blockcount,
404 imap->br_state);
405 return EFSCORRUPTED;
406 }
407
408 int
409 xfs_iomap_write_direct(
410 xfs_inode_t *ip,
411 xfs_off_t offset,
412 size_t count,
413 int flags,
414 xfs_bmbt_irec_t *ret_imap,
415 int *nmaps,
416 int found)
417 {
418 xfs_mount_t *mp = ip->i_mount;
419 xfs_iocore_t *io = &ip->i_iocore;
420 xfs_fileoff_t offset_fsb;
421 xfs_fileoff_t last_fsb;
422 xfs_filblks_t count_fsb, resaligned;
423 xfs_fsblock_t firstfsb;
424 xfs_extlen_t extsz, temp;
425 xfs_fsize_t isize;
426 int nimaps;
427 int bmapi_flag;
428 int quota_flag;
429 int rt;
430 xfs_trans_t *tp;
431 xfs_bmbt_irec_t imap;
432 xfs_bmap_free_t free_list;
433 uint qblocks, resblks, resrtextents;
434 int committed;
435 int error;
436
437 /*
438 * Make sure that the dquots are there. This doesn't hold
439 * the ilock across a disk read.
440 */
441 error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
442 if (error)
443 return XFS_ERROR(error);
444
445 rt = XFS_IS_REALTIME_INODE(ip);
446 extsz = xfs_get_extsz_hint(ip);
447
448 isize = ip->i_size;
449 if (io->io_new_size > isize)
450 isize = io->io_new_size;
451
452 offset_fsb = XFS_B_TO_FSBT(mp, offset);
453 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
454 if ((offset + count) > isize) {
455 error = xfs_iomap_eof_align_last_fsb(mp, io, isize, extsz,
456 &last_fsb);
457 if (error)
458 goto error_out;
459 } else {
460 if (found && (ret_imap->br_startblock == HOLESTARTBLOCK))
461 last_fsb = MIN(last_fsb, (xfs_fileoff_t)
462 ret_imap->br_blockcount +
463 ret_imap->br_startoff);
464 }
465 count_fsb = last_fsb - offset_fsb;
466 ASSERT(count_fsb > 0);
467
468 resaligned = count_fsb;
469 if (unlikely(extsz)) {
470 if ((temp = do_mod(offset_fsb, extsz)))
471 resaligned += temp;
472 if ((temp = do_mod(resaligned, extsz)))
473 resaligned += extsz - temp;
474 }
475
476 if (unlikely(rt)) {
477 resrtextents = qblocks = resaligned;
478 resrtextents /= mp->m_sb.sb_rextsize;
479 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
480 quota_flag = XFS_QMOPT_RES_RTBLKS;
481 } else {
482 resrtextents = 0;
483 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
484 quota_flag = XFS_QMOPT_RES_REGBLKS;
485 }
486
487 /*
488 * Allocate and setup the transaction
489 */
490 xfs_iunlock(ip, XFS_ILOCK_EXCL);
491 tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
492 error = xfs_trans_reserve(tp, resblks,
493 XFS_WRITE_LOG_RES(mp), resrtextents,
494 XFS_TRANS_PERM_LOG_RES,
495 XFS_WRITE_LOG_COUNT);
496 /*
497 * Check for running out of space, note: need lock to return
498 */
499 if (error)
500 xfs_trans_cancel(tp, 0);
501 xfs_ilock(ip, XFS_ILOCK_EXCL);
502 if (error)
503 goto error_out;
504
505 error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip,
506 qblocks, 0, quota_flag);
507 if (error)
508 goto error1;
509
510 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
511 xfs_trans_ihold(tp, ip);
512
513 bmapi_flag = XFS_BMAPI_WRITE;
514 if ((flags & BMAPI_DIRECT) && (offset < ip->i_size || extsz))
515 bmapi_flag |= XFS_BMAPI_PREALLOC;
516
517 /*
518 * Issue the xfs_bmapi() call to allocate the blocks
519 */
520 XFS_BMAP_INIT(&free_list, &firstfsb);
521 nimaps = 1;
522 error = XFS_BMAPI(mp, tp, io, offset_fsb, count_fsb, bmapi_flag,
523 &firstfsb, 0, &imap, &nimaps, &free_list, NULL);
524 if (error)
525 goto error0;
526
527 /*
528 * Complete the transaction
529 */
530 error = xfs_bmap_finish(&tp, &free_list, &committed);
531 if (error)
532 goto error0;
533 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
534 if (error)
535 goto error_out;
536
537 /*
538 * Copy any maps to caller's array and return any error.
539 */
540 if (nimaps == 0) {
541 error = ENOSPC;
542 goto error_out;
543 }
544
545 if (unlikely(!imap.br_startblock && !(io->io_flags & XFS_IOCORE_RT))) {
546 error = xfs_cmn_err_fsblock_zero(ip, &imap);
547 goto error_out;
548 }
549
550 *ret_imap = imap;
551 *nmaps = 1;
552 return 0;
553
554 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
555 xfs_bmap_cancel(&free_list);
556 XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
557
558 error1: /* Just cancel transaction */
559 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
560 *nmaps = 0; /* nothing set-up here */
561
562 error_out:
563 return XFS_ERROR(error);
564 }
565
566 /*
567 * If the caller is doing a write at the end of the file,
568 * then extend the allocation out to the file system's write
569 * iosize. We clean up any extra space left over when the
570 * file is closed in xfs_inactive().
571 *
572 * For sync writes, we are flushing delayed allocate space to
573 * try to make additional space available for allocation near
574 * the filesystem full boundary - preallocation hurts in that
575 * situation, of course.
576 */
577 STATIC int
578 xfs_iomap_eof_want_preallocate(
579 xfs_mount_t *mp,
580 xfs_iocore_t *io,
581 xfs_fsize_t isize,
582 xfs_off_t offset,
583 size_t count,
584 int ioflag,
585 xfs_bmbt_irec_t *imap,
586 int nimaps,
587 int *prealloc)
588 {
589 xfs_fileoff_t start_fsb;
590 xfs_filblks_t count_fsb;
591 xfs_fsblock_t firstblock;
592 int n, error, imaps;
593
594 *prealloc = 0;
595 if ((ioflag & BMAPI_SYNC) || (offset + count) <= isize)
596 return 0;
597
598 /*
599 * If there are any real blocks past eof, then don't
600 * do any speculative allocation.
601 */
602 start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
603 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
604 while (count_fsb > 0) {
605 imaps = nimaps;
606 firstblock = NULLFSBLOCK;
607 error = XFS_BMAPI(mp, NULL, io, start_fsb, count_fsb, 0,
608 &firstblock, 0, imap, &imaps, NULL, NULL);
609 if (error)
610 return error;
611 for (n = 0; n < imaps; n++) {
612 if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
613 (imap[n].br_startblock != DELAYSTARTBLOCK))
614 return 0;
615 start_fsb += imap[n].br_blockcount;
616 count_fsb -= imap[n].br_blockcount;
617 }
618 }
619 *prealloc = 1;
620 return 0;
621 }
622
623 int
624 xfs_iomap_write_delay(
625 xfs_inode_t *ip,
626 xfs_off_t offset,
627 size_t count,
628 int ioflag,
629 xfs_bmbt_irec_t *ret_imap,
630 int *nmaps)
631 {
632 xfs_mount_t *mp = ip->i_mount;
633 xfs_iocore_t *io = &ip->i_iocore;
634 xfs_fileoff_t offset_fsb;
635 xfs_fileoff_t last_fsb;
636 xfs_off_t aligned_offset;
637 xfs_fileoff_t ioalign;
638 xfs_fsblock_t firstblock;
639 xfs_extlen_t extsz;
640 xfs_fsize_t isize;
641 int nimaps;
642 xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
643 int prealloc, fsynced = 0;
644 int error;
645
646 ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
647
648 /*
649 * Make sure that the dquots are there. This doesn't hold
650 * the ilock across a disk read.
651 */
652 error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
653 if (error)
654 return XFS_ERROR(error);
655
656 extsz = xfs_get_extsz_hint(ip);
657 offset_fsb = XFS_B_TO_FSBT(mp, offset);
658
659 retry:
660 isize = ip->i_size;
661 if (io->io_new_size > isize)
662 isize = io->io_new_size;
663
664 error = xfs_iomap_eof_want_preallocate(mp, io, isize, offset, count,
665 ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
666 if (error)
667 return error;
668
669 if (prealloc) {
670 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
671 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
672 last_fsb = ioalign + mp->m_writeio_blocks;
673 } else {
674 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
675 }
676
677 if (prealloc || extsz) {
678 error = xfs_iomap_eof_align_last_fsb(mp, io, isize, extsz,
679 &last_fsb);
680 if (error)
681 return error;
682 }
683
684 nimaps = XFS_WRITE_IMAPS;
685 firstblock = NULLFSBLOCK;
686 error = XFS_BMAPI(mp, NULL, io, offset_fsb,
687 (xfs_filblks_t)(last_fsb - offset_fsb),
688 XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
689 XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
690 &nimaps, NULL, NULL);
691 if (error && (error != ENOSPC))
692 return XFS_ERROR(error);
693
694 /*
695 * If bmapi returned us nothing, and if we didn't get back EDQUOT,
696 * then we must have run out of space - flush delalloc, and retry..
697 */
698 if (nimaps == 0) {
699 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
700 io, offset, count);
701 if (xfs_flush_space(ip, &fsynced, &ioflag))
702 return XFS_ERROR(ENOSPC);
703
704 error = 0;
705 goto retry;
706 }
707
708 if (unlikely(!imap[0].br_startblock && !(io->io_flags & XFS_IOCORE_RT)))
709 return xfs_cmn_err_fsblock_zero(ip, &imap[0]);
710
711 *ret_imap = imap[0];
712 *nmaps = 1;
713
714 return 0;
715 }
716
717 /*
718 * Pass in a delayed allocate extent, convert it to real extents;
719 * return to the caller the extent we create which maps on top of
720 * the originating callers request.
721 *
722 * Called without a lock on the inode.
723 */
724 int
725 xfs_iomap_write_allocate(
726 xfs_inode_t *ip,
727 xfs_off_t offset,
728 size_t count,
729 xfs_bmbt_irec_t *map,
730 int *retmap)
731 {
732 xfs_mount_t *mp = ip->i_mount;
733 xfs_iocore_t *io = &ip->i_iocore;
734 xfs_fileoff_t offset_fsb, last_block;
735 xfs_fileoff_t end_fsb, map_start_fsb;
736 xfs_fsblock_t first_block;
737 xfs_bmap_free_t free_list;
738 xfs_filblks_t count_fsb;
739 xfs_bmbt_irec_t imap[XFS_STRAT_WRITE_IMAPS];
740 xfs_trans_t *tp;
741 int i, nimaps, committed;
742 int error = 0;
743 int nres;
744
745 *retmap = 0;
746
747 /*
748 * Make sure that the dquots are there.
749 */
750 if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
751 return XFS_ERROR(error);
752
753 offset_fsb = XFS_B_TO_FSBT(mp, offset);
754 count_fsb = map->br_blockcount;
755 map_start_fsb = map->br_startoff;
756
757 XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
758
759 while (count_fsb != 0) {
760 /*
761 * Set up a transaction with which to allocate the
762 * backing store for the file. Do allocations in a
763 * loop until we get some space in the range we are
764 * interested in. The other space that might be allocated
765 * is in the delayed allocation extent on which we sit
766 * but before our buffer starts.
767 */
768
769 nimaps = 0;
770 while (nimaps == 0) {
771 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
772 tp->t_flags |= XFS_TRANS_RESERVE;
773 nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
774 error = xfs_trans_reserve(tp, nres,
775 XFS_WRITE_LOG_RES(mp),
776 0, XFS_TRANS_PERM_LOG_RES,
777 XFS_WRITE_LOG_COUNT);
778 if (error) {
779 xfs_trans_cancel(tp, 0);
780 return XFS_ERROR(error);
781 }
782 xfs_ilock(ip, XFS_ILOCK_EXCL);
783 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
784 xfs_trans_ihold(tp, ip);
785
786 XFS_BMAP_INIT(&free_list, &first_block);
787
788 nimaps = XFS_STRAT_WRITE_IMAPS;
789 /*
790 * Ensure we don't go beyond eof - it is possible
791 * the extents changed since we did the read call,
792 * we dropped the ilock in the interim.
793 */
794
795 end_fsb = XFS_B_TO_FSB(mp, ip->i_size);
796 xfs_bmap_last_offset(NULL, ip, &last_block,
797 XFS_DATA_FORK);
798 last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
799 if ((map_start_fsb + count_fsb) > last_block) {
800 count_fsb = last_block - map_start_fsb;
801 if (count_fsb == 0) {
802 error = EAGAIN;
803 goto trans_cancel;
804 }
805 }
806
807 /* Go get the actual blocks */
808 error = XFS_BMAPI(mp, tp, io, map_start_fsb, count_fsb,
809 XFS_BMAPI_WRITE, &first_block, 1,
810 imap, &nimaps, &free_list, NULL);
811 if (error)
812 goto trans_cancel;
813
814 error = xfs_bmap_finish(&tp, &free_list, &committed);
815 if (error)
816 goto trans_cancel;
817
818 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
819 if (error)
820 goto error0;
821
822 xfs_iunlock(ip, XFS_ILOCK_EXCL);
823 }
824
825 /*
826 * See if we were able to allocate an extent that
827 * covers at least part of the callers request
828 */
829 for (i = 0; i < nimaps; i++) {
830 if (unlikely(!imap[i].br_startblock &&
831 !(io->io_flags & XFS_IOCORE_RT)))
832 return xfs_cmn_err_fsblock_zero(ip, &imap[i]);
833 if ((offset_fsb >= imap[i].br_startoff) &&
834 (offset_fsb < (imap[i].br_startoff +
835 imap[i].br_blockcount))) {
836 *map = imap[i];
837 *retmap = 1;
838 XFS_STATS_INC(xs_xstrat_quick);
839 return 0;
840 }
841 count_fsb -= imap[i].br_blockcount;
842 }
843
844 /* So far we have not mapped the requested part of the
845 * file, just surrounding data, try again.
846 */
847 nimaps--;
848 map_start_fsb = imap[nimaps].br_startoff +
849 imap[nimaps].br_blockcount;
850 }
851
852 trans_cancel:
853 xfs_bmap_cancel(&free_list);
854 xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
855 error0:
856 xfs_iunlock(ip, XFS_ILOCK_EXCL);
857 return XFS_ERROR(error);
858 }
859
860 int
861 xfs_iomap_write_unwritten(
862 xfs_inode_t *ip,
863 xfs_off_t offset,
864 size_t count)
865 {
866 xfs_mount_t *mp = ip->i_mount;
867 xfs_iocore_t *io = &ip->i_iocore;
868 xfs_fileoff_t offset_fsb;
869 xfs_filblks_t count_fsb;
870 xfs_filblks_t numblks_fsb;
871 xfs_fsblock_t firstfsb;
872 int nimaps;
873 xfs_trans_t *tp;
874 xfs_bmbt_irec_t imap;
875 xfs_bmap_free_t free_list;
876 uint resblks;
877 int committed;
878 int error;
879
880 xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN,
881 &ip->i_iocore, offset, count);
882
883 offset_fsb = XFS_B_TO_FSBT(mp, offset);
884 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
885 count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
886
887 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
888
889 do {
890 /*
891 * set up a transaction to convert the range of extents
892 * from unwritten to real. Do allocations in a loop until
893 * we have covered the range passed in.
894 */
895 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
896 tp->t_flags |= XFS_TRANS_RESERVE;
897 error = xfs_trans_reserve(tp, resblks,
898 XFS_WRITE_LOG_RES(mp), 0,
899 XFS_TRANS_PERM_LOG_RES,
900 XFS_WRITE_LOG_COUNT);
901 if (error) {
902 xfs_trans_cancel(tp, 0);
903 return XFS_ERROR(error);
904 }
905
906 xfs_ilock(ip, XFS_ILOCK_EXCL);
907 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
908 xfs_trans_ihold(tp, ip);
909
910 /*
911 * Modify the unwritten extent state of the buffer.
912 */
913 XFS_BMAP_INIT(&free_list, &firstfsb);
914 nimaps = 1;
915 error = XFS_BMAPI(mp, tp, io, offset_fsb, count_fsb,
916 XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb,
917 1, &imap, &nimaps, &free_list, NULL);
918 if (error)
919 goto error_on_bmapi_transaction;
920
921 error = xfs_bmap_finish(&(tp), &(free_list), &committed);
922 if (error)
923 goto error_on_bmapi_transaction;
924
925 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
926 xfs_iunlock(ip, XFS_ILOCK_EXCL);
927 if (error)
928 return XFS_ERROR(error);
929
930 if (unlikely(!imap.br_startblock &&
931 !(io->io_flags & XFS_IOCORE_RT)))
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 }
Linux branches of Pieter du Preez