Merge branch 'atmel'
[linux-2.6] / fs / xfs / xfs_iomap.c
1 /*
2  * Copyright (c) 2000-2005 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_dir.h"
27 #include "xfs_dir2.h"
28 #include "xfs_alloc.h"
29 #include "xfs_dmapi.h"
30 #include "xfs_quota.h"
31 #include "xfs_mount.h"
32 #include "xfs_bmap_btree.h"
33 #include "xfs_alloc_btree.h"
34 #include "xfs_ialloc_btree.h"
35 #include "xfs_dir_sf.h"
36 #include "xfs_dir2_sf.h"
37 #include "xfs_attr_sf.h"
38 #include "xfs_dinode.h"
39 #include "xfs_inode.h"
40 #include "xfs_ialloc.h"
41 #include "xfs_btree.h"
42 #include "xfs_bmap.h"
43 #include "xfs_bit.h"
44 #include "xfs_rtalloc.h"
45 #include "xfs_error.h"
46 #include "xfs_itable.h"
47 #include "xfs_rw.h"
48 #include "xfs_acl.h"
49 #include "xfs_cap.h"
50 #include "xfs_mac.h"
51 #include "xfs_attr.h"
52 #include "xfs_buf_item.h"
53 #include "xfs_trans_space.h"
54 #include "xfs_utils.h"
55 #include "xfs_iomap.h"
56
57 #if defined(XFS_RW_TRACE)
58 void
59 xfs_iomap_enter_trace(
60         int             tag,
61         xfs_iocore_t    *io,
62         xfs_off_t       offset,
63         ssize_t         count)
64 {
65         xfs_inode_t     *ip = XFS_IO_INODE(io);
66
67         if (!ip->i_rwtrace)
68                 return;
69
70         ktrace_enter(ip->i_rwtrace,
71                 (void *)((unsigned long)tag),
72                 (void *)ip,
73                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
74                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
75                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
76                 (void *)((unsigned long)(offset & 0xffffffff)),
77                 (void *)((unsigned long)count),
78                 (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
79                 (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
80                 (void *)NULL,
81                 (void *)NULL,
82                 (void *)NULL,
83                 (void *)NULL,
84                 (void *)NULL,
85                 (void *)NULL,
86                 (void *)NULL);
87 }
88
89 void
90 xfs_iomap_map_trace(
91         int             tag,
92         xfs_iocore_t    *io,
93         xfs_off_t       offset,
94         ssize_t         count,
95         xfs_iomap_t     *iomapp,
96         xfs_bmbt_irec_t *imapp,
97         int             flags)
98 {
99         xfs_inode_t     *ip = XFS_IO_INODE(io);
100
101         if (!ip->i_rwtrace)
102                 return;
103
104         ktrace_enter(ip->i_rwtrace,
105                 (void *)((unsigned long)tag),
106                 (void *)ip,
107                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
108                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
109                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
110                 (void *)((unsigned long)(offset & 0xffffffff)),
111                 (void *)((unsigned long)count),
112                 (void *)((unsigned long)flags),
113                 (void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)),
114                 (void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)),
115                 (void *)((unsigned long)(iomapp->iomap_delta)),
116                 (void *)((unsigned long)(iomapp->iomap_bsize)),
117                 (void *)((unsigned long)(iomapp->iomap_bn)),
118                 (void *)(__psint_t)(imapp->br_startoff),
119                 (void *)((unsigned long)(imapp->br_blockcount)),
120                 (void *)(__psint_t)(imapp->br_startblock));
121 }
122 #else
123 #define xfs_iomap_enter_trace(tag, io, offset, count)
124 #define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags)
125 #endif
126
127 #define XFS_WRITEIO_ALIGN(mp,off)       (((off) >> mp->m_writeio_log) \
128                                                 << mp->m_writeio_log)
129 #define XFS_STRAT_WRITE_IMAPS   2
130 #define XFS_WRITE_IMAPS         XFS_BMAP_MAX_NMAP
131
132 STATIC int
133 xfs_imap_to_bmap(
134         xfs_iocore_t    *io,
135         xfs_off_t       offset,
136         xfs_bmbt_irec_t *imap,
137         xfs_iomap_t     *iomapp,
138         int             imaps,                  /* Number of imap entries */
139         int             iomaps,                 /* Number of iomap entries */
140         int             flags)
141 {
142         xfs_mount_t     *mp;
143         xfs_fsize_t     nisize;
144         int             pbm;
145         xfs_fsblock_t   start_block;
146
147         mp = io->io_mount;
148         nisize = XFS_SIZE(mp, io);
149         if (io->io_new_size > nisize)
150                 nisize = io->io_new_size;
151
152         for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
153                 iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
154                 iomapp->iomap_delta = offset - iomapp->iomap_offset;
155                 iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
156                 iomapp->iomap_flags = flags;
157
158                 if (io->io_flags & XFS_IOCORE_RT) {
159                         iomapp->iomap_flags |= IOMAP_REALTIME;
160                         iomapp->iomap_target = mp->m_rtdev_targp;
161                 } else {
162                         iomapp->iomap_target = mp->m_ddev_targp;
163                 }
164                 start_block = imap->br_startblock;
165                 if (start_block == HOLESTARTBLOCK) {
166                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
167                         iomapp->iomap_flags |= IOMAP_HOLE;
168                 } else if (start_block == DELAYSTARTBLOCK) {
169                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
170                         iomapp->iomap_flags |= IOMAP_DELAY;
171                 } else {
172                         iomapp->iomap_bn = XFS_FSB_TO_DB_IO(io, start_block);
173                         if (ISUNWRITTEN(imap))
174                                 iomapp->iomap_flags |= IOMAP_UNWRITTEN;
175                 }
176
177                 if ((iomapp->iomap_offset + iomapp->iomap_bsize) >= nisize) {
178                         iomapp->iomap_flags |= IOMAP_EOF;
179                 }
180
181                 offset += iomapp->iomap_bsize - iomapp->iomap_delta;
182         }
183         return pbm;     /* Return the number filled */
184 }
185
186 int
187 xfs_iomap(
188         xfs_iocore_t    *io,
189         xfs_off_t       offset,
190         ssize_t         count,
191         int             flags,
192         xfs_iomap_t     *iomapp,
193         int             *niomaps)
194 {
195         xfs_mount_t     *mp = io->io_mount;
196         xfs_fileoff_t   offset_fsb, end_fsb;
197         int             error = 0;
198         int             lockmode = 0;
199         xfs_bmbt_irec_t imap;
200         int             nimaps = 1;
201         int             bmapi_flags = 0;
202         int             iomap_flags = 0;
203
204         if (XFS_FORCED_SHUTDOWN(mp))
205                 return XFS_ERROR(EIO);
206
207         switch (flags &
208                 (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE |
209                  BMAPI_UNWRITTEN | BMAPI_DEVICE)) {
210         case BMAPI_READ:
211                 xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, io, offset, count);
212                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
213                 bmapi_flags = XFS_BMAPI_ENTIRE;
214                 break;
215         case BMAPI_WRITE:
216                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, io, offset, count);
217                 lockmode = XFS_ILOCK_EXCL|XFS_EXTSIZE_WR;
218                 if (flags & BMAPI_IGNSTATE)
219                         bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE;
220                 XFS_ILOCK(mp, io, lockmode);
221                 break;
222         case BMAPI_ALLOCATE:
223                 xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, io, offset, count);
224                 lockmode = XFS_ILOCK_SHARED|XFS_EXTSIZE_RD;
225                 bmapi_flags = XFS_BMAPI_ENTIRE;
226                 /* Attempt non-blocking lock */
227                 if (flags & BMAPI_TRYLOCK) {
228                         if (!XFS_ILOCK_NOWAIT(mp, io, lockmode))
229                                 return XFS_ERROR(EAGAIN);
230                 } else {
231                         XFS_ILOCK(mp, io, lockmode);
232                 }
233                 break;
234         case BMAPI_UNWRITTEN:
235                 goto phase2;
236         case BMAPI_DEVICE:
237                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
238                 iomapp->iomap_target = io->io_flags & XFS_IOCORE_RT ?
239                         mp->m_rtdev_targp : mp->m_ddev_targp;
240                 error = 0;
241                 *niomaps = 1;
242                 goto out;
243         default:
244                 BUG();
245         }
246
247         ASSERT(offset <= mp->m_maxioffset);
248         if ((xfs_fsize_t)offset + count > mp->m_maxioffset)
249                 count = mp->m_maxioffset - offset;
250         end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
251         offset_fsb = XFS_B_TO_FSBT(mp, offset);
252
253         error = XFS_BMAPI(mp, NULL, io, offset_fsb,
254                         (xfs_filblks_t)(end_fsb - offset_fsb),
255                         bmapi_flags,  NULL, 0, &imap,
256                         &nimaps, NULL);
257
258         if (error)
259                 goto out;
260
261 phase2:
262         switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE|BMAPI_UNWRITTEN)) {
263         case BMAPI_WRITE:
264                 /* If we found an extent, return it */
265                 if (nimaps &&
266                     (imap.br_startblock != HOLESTARTBLOCK) && 
267                     (imap.br_startblock != DELAYSTARTBLOCK)) {
268                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
269                                         offset, count, iomapp, &imap, flags);
270                         break;
271                 }
272
273                 if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
274                         error = XFS_IOMAP_WRITE_DIRECT(mp, io, offset,
275                                         count, flags, &imap, &nimaps, nimaps);
276                 } else {
277                         error = XFS_IOMAP_WRITE_DELAY(mp, io, offset, count,
278                                         flags, &imap, &nimaps);
279                 }
280                 if (!error) {
281                         xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, io,
282                                         offset, count, iomapp, &imap, flags);
283                 }
284                 iomap_flags = IOMAP_NEW;
285                 break;
286         case BMAPI_ALLOCATE:
287                 /* If we found an extent, return it */
288                 XFS_IUNLOCK(mp, io, lockmode);
289                 lockmode = 0;
290
291                 if (nimaps && !ISNULLSTARTBLOCK(imap.br_startblock)) {
292                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
293                                         offset, count, iomapp, &imap, flags);
294                         break;
295                 }
296
297                 error = XFS_IOMAP_WRITE_ALLOCATE(mp, io, offset, count,
298                                                  &imap, &nimaps);
299                 break;
300         case BMAPI_UNWRITTEN:
301                 lockmode = 0;
302                 error = XFS_IOMAP_WRITE_UNWRITTEN(mp, io, offset, count);
303                 nimaps = 0;
304                 break;
305         }
306
307         if (nimaps) {
308                 *niomaps = xfs_imap_to_bmap(io, offset, &imap,
309                                             iomapp, nimaps, *niomaps, iomap_flags);
310         } else if (niomaps) {
311                 *niomaps = 0;
312         }
313
314 out:
315         if (lockmode)
316                 XFS_IUNLOCK(mp, io, lockmode);
317         return XFS_ERROR(error);
318 }
319
320 STATIC int
321 xfs_flush_space(
322         xfs_inode_t     *ip,
323         int             *fsynced,
324         int             *ioflags)
325 {
326         switch (*fsynced) {
327         case 0:
328                 if (ip->i_delayed_blks) {
329                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
330                         xfs_flush_inode(ip);
331                         xfs_ilock(ip, XFS_ILOCK_EXCL);
332                         *fsynced = 1;
333                 } else {
334                         *ioflags |= BMAPI_SYNC;
335                         *fsynced = 2;
336                 }
337                 return 0;
338         case 1:
339                 *fsynced = 2;
340                 *ioflags |= BMAPI_SYNC;
341                 return 0;
342         case 2:
343                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
344                 xfs_flush_device(ip);
345                 xfs_ilock(ip, XFS_ILOCK_EXCL);
346                 *fsynced = 3;
347                 return 0;
348         }
349         return 1;
350 }
351
352 int
353 xfs_iomap_write_direct(
354         xfs_inode_t     *ip,
355         xfs_off_t       offset,
356         size_t          count,
357         int             flags,
358         xfs_bmbt_irec_t *ret_imap,
359         int             *nmaps,
360         int             found)
361 {
362         xfs_mount_t     *mp = ip->i_mount;
363         xfs_iocore_t    *io = &ip->i_iocore;
364         xfs_fileoff_t   offset_fsb;
365         xfs_fileoff_t   last_fsb;
366         xfs_filblks_t   count_fsb;
367         xfs_fsblock_t   firstfsb;
368         int             nimaps;
369         int             error;
370         int             bmapi_flag;
371         int             quota_flag;
372         int             rt;
373         xfs_trans_t     *tp;
374         xfs_bmbt_irec_t imap;
375         xfs_bmap_free_t free_list;
376         xfs_filblks_t   qblocks, resblks;
377         int             committed;
378         int             resrtextents;
379
380         /*
381          * Make sure that the dquots are there. This doesn't hold
382          * the ilock across a disk read.
383          */
384         error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
385         if (error)
386                 return XFS_ERROR(error);
387
388         offset_fsb = XFS_B_TO_FSBT(mp, offset);
389         last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
390         count_fsb = last_fsb - offset_fsb;
391         if (found && (ret_imap->br_startblock == HOLESTARTBLOCK)) {
392                 xfs_fileoff_t   map_last_fsb;
393
394                 map_last_fsb = ret_imap->br_blockcount + ret_imap->br_startoff;
395                 if (map_last_fsb < last_fsb) {
396                         last_fsb = map_last_fsb;
397                         count_fsb = last_fsb - offset_fsb;
398                 }
399                 ASSERT(count_fsb > 0);
400         }
401
402         /*
403          * Determine if reserving space on the data or realtime partition.
404          */
405         if ((rt = XFS_IS_REALTIME_INODE(ip))) {
406                 xfs_extlen_t    extsz;
407
408                 if (!(extsz = ip->i_d.di_extsize))
409                         extsz = mp->m_sb.sb_rextsize;
410                 resrtextents = qblocks = (count_fsb + extsz - 1);
411                 do_div(resrtextents, mp->m_sb.sb_rextsize);
412                 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
413                 quota_flag = XFS_QMOPT_RES_RTBLKS;
414         } else {
415                 resrtextents = 0;
416                 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, count_fsb);
417                 quota_flag = XFS_QMOPT_RES_REGBLKS;
418         }
419
420         /*
421          * Allocate and setup the transaction
422          */
423         xfs_iunlock(ip, XFS_ILOCK_EXCL);
424         tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
425         error = xfs_trans_reserve(tp, resblks,
426                         XFS_WRITE_LOG_RES(mp), resrtextents,
427                         XFS_TRANS_PERM_LOG_RES,
428                         XFS_WRITE_LOG_COUNT);
429
430         /*
431          * Check for running out of space, note: need lock to return
432          */
433         if (error)
434                 xfs_trans_cancel(tp, 0);
435         xfs_ilock(ip, XFS_ILOCK_EXCL);
436         if (error)
437                 goto error_out;
438
439         if (XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag)) {
440                 error = (EDQUOT);
441                 goto error1;
442         }
443
444         bmapi_flag = XFS_BMAPI_WRITE;
445         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
446         xfs_trans_ihold(tp, ip);
447
448         if (!(flags & BMAPI_MMAP) && (offset < ip->i_d.di_size || rt))
449                 bmapi_flag |= XFS_BMAPI_PREALLOC;
450
451         /*
452          * Issue the bmapi() call to allocate the blocks
453          */
454         XFS_BMAP_INIT(&free_list, &firstfsb);
455         nimaps = 1;
456         error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
457                 bmapi_flag, &firstfsb, 0, &imap, &nimaps, &free_list);
458         if (error)
459                 goto error0;
460
461         /*
462          * Complete the transaction
463          */
464         error = xfs_bmap_finish(&tp, &free_list, firstfsb, &committed);
465         if (error)
466                 goto error0;
467         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
468         if (error)
469                 goto error_out;
470
471         /*
472          * Copy any maps to caller's array and return any error.
473          */
474         if (nimaps == 0) {
475                 error = (ENOSPC);
476                 goto error_out;
477         }
478
479         *ret_imap = imap;
480         *nmaps = 1;
481         if ( !(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
482                 cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
483                         "start_block : %llx start_off : %llx blkcnt : %llx "
484                         "extent-state : %x \n",
485                         (ip->i_mount)->m_fsname,
486                         (long long)ip->i_ino,
487                         ret_imap->br_startblock, ret_imap->br_startoff,
488                         ret_imap->br_blockcount,ret_imap->br_state);
489         }
490         return 0;
491
492 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
493         xfs_bmap_cancel(&free_list);
494         XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
495
496 error1: /* Just cancel transaction */
497         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
498         *nmaps = 0;     /* nothing set-up here */
499
500 error_out:
501         return XFS_ERROR(error);
502 }
503
504 int
505 xfs_iomap_write_delay(
506         xfs_inode_t     *ip,
507         xfs_off_t       offset,
508         size_t          count,
509         int             ioflag,
510         xfs_bmbt_irec_t *ret_imap,
511         int             *nmaps)
512 {
513         xfs_mount_t     *mp = ip->i_mount;
514         xfs_iocore_t    *io = &ip->i_iocore;
515         xfs_fileoff_t   offset_fsb;
516         xfs_fileoff_t   last_fsb;
517         xfs_fsize_t     isize;
518         xfs_fsblock_t   firstblock;
519         int             nimaps;
520         int             error;
521         xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
522         int             aeof;
523         int             fsynced = 0;
524
525         ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
526
527         /*
528          * Make sure that the dquots are there. This doesn't hold
529          * the ilock across a disk read.
530          */
531
532         error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
533         if (error)
534                 return XFS_ERROR(error);
535
536 retry:
537         isize = ip->i_d.di_size;
538         if (io->io_new_size > isize) {
539                 isize = io->io_new_size;
540         }
541
542         aeof = 0;
543         offset_fsb = XFS_B_TO_FSBT(mp, offset);
544         last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
545         /*
546          * If the caller is doing a write at the end of the file,
547          * then extend the allocation (and the buffer used for the write)
548          * out to the file system's write iosize.  We clean up any extra
549          * space left over when the file is closed in xfs_inactive().
550          *
551          * For sync writes, we are flushing delayed allocate space to
552          * try to make additional space available for allocation near
553          * the filesystem full boundary - preallocation hurts in that
554          * situation, of course.
555          */
556         if (!(ioflag & BMAPI_SYNC) && ((offset + count) > ip->i_d.di_size)) {
557                 xfs_off_t       aligned_offset;
558                 xfs_filblks_t   count_fsb;
559                 unsigned int    iosize;
560                 xfs_fileoff_t   ioalign;
561                 int             n;
562                 xfs_fileoff_t   start_fsb;
563
564                 /*
565                  * If there are any real blocks past eof, then don't
566                  * do any speculative allocation.
567                  */
568                 start_fsb = XFS_B_TO_FSBT(mp,
569                                         ((xfs_ufsize_t)(offset + count - 1)));
570                 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
571                 while (count_fsb > 0) {
572                         nimaps = XFS_WRITE_IMAPS;
573                         error = XFS_BMAPI(mp, NULL, io, start_fsb, count_fsb,
574                                         0, &firstblock, 0, imap, &nimaps, NULL);
575                         if (error) {
576                                 return error;
577                         }
578                         for (n = 0; n < nimaps; n++) {
579                                 if ( !(io->io_flags & XFS_IOCORE_RT)  && 
580                                         !imap[n].br_startblock) {
581                                         cmn_err(CE_PANIC,"Access to block "
582                                                 "zero:  fs <%s> inode: %lld "
583                                                 "start_block : %llx start_off "
584                                                 ": %llx blkcnt : %llx "
585                                                 "extent-state : %x \n",
586                                                 (ip->i_mount)->m_fsname,
587                                                 (long long)ip->i_ino,
588                                                 imap[n].br_startblock,
589                                                 imap[n].br_startoff,
590                                                 imap[n].br_blockcount,
591                                                 imap[n].br_state);
592                                 }
593                                 if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
594                                     (imap[n].br_startblock != DELAYSTARTBLOCK)) {
595                                         goto write_map;
596                                 }
597                                 start_fsb += imap[n].br_blockcount;
598                                 count_fsb -= imap[n].br_blockcount;
599                         }
600                 }
601                 iosize = mp->m_writeio_blocks;
602                 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
603                 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
604                 last_fsb = ioalign + iosize;
605                 aeof = 1;
606         }
607 write_map:
608         nimaps = XFS_WRITE_IMAPS;
609         firstblock = NULLFSBLOCK;
610
611         /*
612          * If mounted with the "-o swalloc" option, roundup the allocation
613          * request to a stripe width boundary if the file size is >=
614          * stripe width and we are allocating past the allocation eof.
615          */
616         if (!(io->io_flags & XFS_IOCORE_RT) && mp->m_swidth 
617             && (mp->m_flags & XFS_MOUNT_SWALLOC)
618             && (isize >= XFS_FSB_TO_B(mp, mp->m_swidth)) && aeof) {
619                 int eof;
620                 xfs_fileoff_t new_last_fsb;
621
622                 new_last_fsb = roundup_64(last_fsb, mp->m_swidth);
623                 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
624                 if (error) {
625                         return error;
626                 }
627                 if (eof) {
628                         last_fsb = new_last_fsb;
629                 }
630         /*
631          * Roundup the allocation request to a stripe unit (m_dalign) boundary
632          * if the file size is >= stripe unit size, and we are allocating past
633          * the allocation eof.
634          */
635         } else if (!(io->io_flags & XFS_IOCORE_RT) && mp->m_dalign &&
636                    (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)) && aeof) {
637                 int eof;
638                 xfs_fileoff_t new_last_fsb;
639                 new_last_fsb = roundup_64(last_fsb, mp->m_dalign);
640                 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
641                 if (error) {
642                         return error;
643                 }
644                 if (eof) {
645                         last_fsb = new_last_fsb;
646                 }
647         /*
648          * Round up the allocation request to a real-time extent boundary
649          * if the file is on the real-time subvolume.
650          */
651         } else if (io->io_flags & XFS_IOCORE_RT && aeof) {
652                 int eof;
653                 xfs_fileoff_t new_last_fsb;
654
655                 new_last_fsb = roundup_64(last_fsb, mp->m_sb.sb_rextsize);
656                 error = XFS_BMAP_EOF(mp, io, new_last_fsb, XFS_DATA_FORK, &eof);
657                 if (error) {
658                         return error;
659                 }
660                 if (eof)
661                         last_fsb = new_last_fsb;
662         }
663         error = xfs_bmapi(NULL, ip, offset_fsb,
664                           (xfs_filblks_t)(last_fsb - offset_fsb),
665                           XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
666                           XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
667                           &nimaps, NULL);
668         /*
669          * This can be EDQUOT, if nimaps == 0
670          */
671         if (error && (error != ENOSPC)) {
672                 return XFS_ERROR(error);
673         }
674         /*
675          * If bmapi returned us nothing, and if we didn't get back EDQUOT,
676          * then we must have run out of space.
677          */
678         if (nimaps == 0) {
679                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
680                                         io, offset, count);
681                 if (xfs_flush_space(ip, &fsynced, &ioflag))
682                         return XFS_ERROR(ENOSPC);
683
684                 error = 0;
685                 goto retry;
686         }
687
688         *ret_imap = imap[0];
689         *nmaps = 1;
690         if ( !(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
691                 cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
692                         "start_block : %llx start_off : %llx blkcnt : %llx "
693                         "extent-state : %x \n",
694                         (ip->i_mount)->m_fsname,
695                         (long long)ip->i_ino,
696                         ret_imap->br_startblock, ret_imap->br_startoff,
697                         ret_imap->br_blockcount,ret_imap->br_state);
698         }
699         return 0;
700 }
701
702 /*
703  * Pass in a delayed allocate extent, convert it to real extents;
704  * return to the caller the extent we create which maps on top of
705  * the originating callers request.
706  *
707  * Called without a lock on the inode.
708  */
709 int
710 xfs_iomap_write_allocate(
711         xfs_inode_t     *ip,
712         xfs_off_t       offset,
713         size_t          count,
714         xfs_bmbt_irec_t *map,
715         int             *retmap)
716 {
717         xfs_mount_t     *mp = ip->i_mount;
718         xfs_iocore_t    *io = &ip->i_iocore;
719         xfs_fileoff_t   offset_fsb, last_block;
720         xfs_fileoff_t   end_fsb, map_start_fsb;
721         xfs_fsblock_t   first_block;
722         xfs_bmap_free_t free_list;
723         xfs_filblks_t   count_fsb;
724         xfs_bmbt_irec_t imap[XFS_STRAT_WRITE_IMAPS];
725         xfs_trans_t     *tp;
726         int             i, nimaps, committed;
727         int             error = 0;
728         int             nres;
729
730         *retmap = 0;
731
732         /*
733          * Make sure that the dquots are there.
734          */
735         if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
736                 return XFS_ERROR(error);
737
738         offset_fsb = XFS_B_TO_FSBT(mp, offset);
739         count_fsb = map->br_blockcount;
740         map_start_fsb = map->br_startoff;
741
742         XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
743
744         while (count_fsb != 0) {
745                 /*
746                  * Set up a transaction with which to allocate the
747                  * backing store for the file.  Do allocations in a
748                  * loop until we get some space in the range we are
749                  * interested in.  The other space that might be allocated
750                  * is in the delayed allocation extent on which we sit
751                  * but before our buffer starts.
752                  */
753
754                 nimaps = 0;
755                 while (nimaps == 0) {
756                         tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
757                         nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
758                         error = xfs_trans_reserve(tp, nres,
759                                         XFS_WRITE_LOG_RES(mp),
760                                         0, XFS_TRANS_PERM_LOG_RES,
761                                         XFS_WRITE_LOG_COUNT);
762                         if (error == ENOSPC) {
763                                 error = xfs_trans_reserve(tp, 0,
764                                                 XFS_WRITE_LOG_RES(mp),
765                                                 0,
766                                                 XFS_TRANS_PERM_LOG_RES,
767                                                 XFS_WRITE_LOG_COUNT);
768                         }
769                         if (error) {
770                                 xfs_trans_cancel(tp, 0);
771                                 return XFS_ERROR(error);
772                         }
773                         xfs_ilock(ip, XFS_ILOCK_EXCL);
774                         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
775                         xfs_trans_ihold(tp, ip);
776
777                         XFS_BMAP_INIT(&free_list, &first_block);
778
779                         nimaps = XFS_STRAT_WRITE_IMAPS;
780                         /*
781                          * Ensure we don't go beyond eof - it is possible
782                          * the extents changed since we did the read call,
783                          * we dropped the ilock in the interim.
784                          */
785
786                         end_fsb = XFS_B_TO_FSB(mp, ip->i_d.di_size);
787                         xfs_bmap_last_offset(NULL, ip, &last_block,
788                                 XFS_DATA_FORK);
789                         last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
790                         if ((map_start_fsb + count_fsb) > last_block) {
791                                 count_fsb = last_block - map_start_fsb;
792                                 if (count_fsb == 0) {
793                                         error = EAGAIN;
794                                         goto trans_cancel;
795                                 }
796                         }
797
798                         /* Go get the actual blocks */
799                         error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
800                                         XFS_BMAPI_WRITE, &first_block, 1,
801                                         imap, &nimaps, &free_list);
802                         if (error)
803                                 goto trans_cancel;
804
805                         error = xfs_bmap_finish(&tp, &free_list,
806                                         first_block, &committed);
807                         if (error)
808                                 goto trans_cancel;
809
810                         error = xfs_trans_commit(tp,
811                                         XFS_TRANS_RELEASE_LOG_RES, NULL);
812                         if (error)
813                                 goto error0;
814
815                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
816                 }
817
818                 /*
819                  * See if we were able to allocate an extent that
820                  * covers at least part of the callers request
821                  */
822
823                 for (i = 0; i < nimaps; i++) {
824                         if ( !(io->io_flags & XFS_IOCORE_RT)  && 
825                                 !imap[i].br_startblock) {
826                                 cmn_err(CE_PANIC,"Access to block zero:  "
827                                         "fs <%s> inode: %lld "
828                                         "start_block : %llx start_off : %llx " 
829                                         "blkcnt : %llx extent-state : %x \n",
830                                         (ip->i_mount)->m_fsname,
831                                         (long long)ip->i_ino,
832                                         imap[i].br_startblock,
833                                         imap[i].br_startoff,
834                                         imap[i].br_blockcount,imap[i].br_state);
835                         }
836                         if ((offset_fsb >= imap[i].br_startoff) &&
837                             (offset_fsb < (imap[i].br_startoff +
838                                            imap[i].br_blockcount))) {
839                                 *map = imap[i];
840                                 *retmap = 1;
841                                 XFS_STATS_INC(xs_xstrat_quick);
842                                 return 0;
843                         }
844                         count_fsb -= imap[i].br_blockcount;
845                 }
846
847                 /* So far we have not mapped the requested part of the
848                  * file, just surrounding data, try again.
849                  */
850                 nimaps--;
851                 map_start_fsb = imap[nimaps].br_startoff +
852                                 imap[nimaps].br_blockcount;
853         }
854
855 trans_cancel:
856         xfs_bmap_cancel(&free_list);
857         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
858 error0:
859         xfs_iunlock(ip, XFS_ILOCK_EXCL);
860         return XFS_ERROR(error);
861 }
862
863 int
864 xfs_iomap_write_unwritten(
865         xfs_inode_t     *ip,
866         xfs_off_t       offset,
867         size_t          count)
868 {
869         xfs_mount_t     *mp = ip->i_mount;
870         xfs_iocore_t    *io = &ip->i_iocore;
871         xfs_trans_t     *tp;
872         xfs_fileoff_t   offset_fsb;
873         xfs_filblks_t   count_fsb;
874         xfs_filblks_t   numblks_fsb;
875         xfs_bmbt_irec_t imap;
876         int             committed;
877         int             error;
878         int             nres;
879         int             nimaps;
880         xfs_fsblock_t   firstfsb;
881         xfs_bmap_free_t free_list;
882
883         xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN,
884                                 &ip->i_iocore, offset, count);
885
886         offset_fsb = XFS_B_TO_FSBT(mp, offset);
887         count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
888         count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
889
890         do {
891                 nres = XFS_DIOSTRAT_SPACE_RES(mp, 0);
892
893                 /*
894                  * set up a transaction to convert the range of extents
895                  * from unwritten to real. Do allocations in a loop until
896                  * we have covered the range passed in.
897                  */
898
899                 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
900                 error = xfs_trans_reserve(tp, nres,
901                                 XFS_WRITE_LOG_RES(mp), 0,
902                                 XFS_TRANS_PERM_LOG_RES,
903                                 XFS_WRITE_LOG_COUNT);
904                 if (error) {
905                         xfs_trans_cancel(tp, 0);
906                         goto error0;
907                 }
908
909                 xfs_ilock(ip, XFS_ILOCK_EXCL);
910                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
911                 xfs_trans_ihold(tp, ip);
912
913                 /*
914                  * Modify the unwritten extent state of the buffer.
915                  */
916                 XFS_BMAP_INIT(&free_list, &firstfsb);
917                 nimaps = 1;
918                 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
919                                   XFS_BMAPI_WRITE, &firstfsb,
920                                   1, &imap, &nimaps, &free_list);
921                 if (error)
922                         goto error_on_bmapi_transaction;
923
924                 error = xfs_bmap_finish(&(tp), &(free_list),
925                                 firstfsb, &committed);
926                 if (error)
927                         goto error_on_bmapi_transaction;
928
929                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
930                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
931                 if (error)
932                         goto error0;
933                 
934                 if ( !(io->io_flags & XFS_IOCORE_RT)  && !imap.br_startblock) {
935                         cmn_err(CE_PANIC,"Access to block zero:  fs <%s> "
936                                 "inode: %lld start_block : %llx start_off : "
937                                 "%llx blkcnt : %llx extent-state : %x \n",
938                                 (ip->i_mount)->m_fsname,
939                                 (long long)ip->i_ino,
940                                 imap.br_startblock,imap.br_startoff,
941                                 imap.br_blockcount,imap.br_state);
942                 }
943
944                 if ((numblks_fsb = imap.br_blockcount) == 0) {
945                         /*
946                          * The numblks_fsb value should always get
947                          * smaller, otherwise the loop is stuck.
948                          */
949                         ASSERT(imap.br_blockcount);
950                         break;
951                 }
952                 offset_fsb += numblks_fsb;
953                 count_fsb -= numblks_fsb;
954         } while (count_fsb > 0);
955
956         return 0;
957
958 error_on_bmapi_transaction:
959         xfs_bmap_cancel(&free_list);
960         xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
961         xfs_iunlock(ip, XFS_ILOCK_EXCL);
962 error0:
963         return XFS_ERROR(error);
964 }