Automatic merge of /spare/repo/netdev-2.6 branch viro
[linux-2.6] / fs / xfs / xfs_iomap.c
1 /*
2  * Copyright (c) 2000-2004 Silicon Graphics, Inc.  All Rights Reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it would be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11  *
12  * Further, this software is distributed without any warranty that it is
13  * free of the rightful claim of any third person regarding infringement
14  * or the like.  Any license provided herein, whether implied or
15  * otherwise, applies only to this software file.  Patent licenses, if
16  * any, provided herein do not apply to combinations of this program with
17  * other software, or any other product whatsoever.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write the Free Software Foundation, Inc., 59
21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22  *
23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24  * Mountain View, CA  94043, or:
25  *
26  * http://www.sgi.com
27  *
28  * For further information regarding this notice, see:
29  *
30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31  */
32
33 #include "xfs.h"
34
35 #include "xfs_fs.h"
36 #include "xfs_inum.h"
37 #include "xfs_log.h"
38 #include "xfs_trans.h"
39 #include "xfs_sb.h"
40 #include "xfs_ag.h"
41 #include "xfs_dir.h"
42 #include "xfs_dir2.h"
43 #include "xfs_alloc.h"
44 #include "xfs_dmapi.h"
45 #include "xfs_quota.h"
46 #include "xfs_mount.h"
47 #include "xfs_alloc_btree.h"
48 #include "xfs_bmap_btree.h"
49 #include "xfs_ialloc_btree.h"
50 #include "xfs_btree.h"
51 #include "xfs_ialloc.h"
52 #include "xfs_attr_sf.h"
53 #include "xfs_dir_sf.h"
54 #include "xfs_dir2_sf.h"
55 #include "xfs_dinode.h"
56 #include "xfs_inode.h"
57 #include "xfs_bmap.h"
58 #include "xfs_bit.h"
59 #include "xfs_rtalloc.h"
60 #include "xfs_error.h"
61 #include "xfs_itable.h"
62 #include "xfs_rw.h"
63 #include "xfs_acl.h"
64 #include "xfs_cap.h"
65 #include "xfs_mac.h"
66 #include "xfs_attr.h"
67 #include "xfs_buf_item.h"
68 #include "xfs_trans_space.h"
69 #include "xfs_utils.h"
70 #include "xfs_iomap.h"
71
72 #if defined(XFS_RW_TRACE)
73 void
74 xfs_iomap_enter_trace(
75         int             tag,
76         xfs_iocore_t    *io,
77         xfs_off_t       offset,
78         ssize_t         count)
79 {
80         xfs_inode_t     *ip = XFS_IO_INODE(io);
81
82         if (!ip->i_rwtrace)
83                 return;
84
85         ktrace_enter(ip->i_rwtrace,
86                 (void *)((unsigned long)tag),
87                 (void *)ip,
88                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
89                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
90                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
91                 (void *)((unsigned long)(offset & 0xffffffff)),
92                 (void *)((unsigned long)count),
93                 (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
94                 (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
95                 (void *)NULL,
96                 (void *)NULL,
97                 (void *)NULL,
98                 (void *)NULL,
99                 (void *)NULL,
100                 (void *)NULL,
101                 (void *)NULL);
102 }
103
104 void
105 xfs_iomap_map_trace(
106         int             tag,
107         xfs_iocore_t    *io,
108         xfs_off_t       offset,
109         ssize_t         count,
110         xfs_iomap_t     *iomapp,
111         xfs_bmbt_irec_t *imapp,
112         int             flags)
113 {
114         xfs_inode_t     *ip = XFS_IO_INODE(io);
115
116         if (!ip->i_rwtrace)
117                 return;
118
119         ktrace_enter(ip->i_rwtrace,
120                 (void *)((unsigned long)tag),
121                 (void *)ip,
122                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
123                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
124                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
125                 (void *)((unsigned long)(offset & 0xffffffff)),
126                 (void *)((unsigned long)count),
127                 (void *)((unsigned long)flags),
128                 (void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)),
129                 (void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)),
130                 (void *)((unsigned long)(iomapp->iomap_delta)),
131                 (void *)((unsigned long)(iomapp->iomap_bsize)),
132                 (void *)((unsigned long)(iomapp->iomap_bn)),
133                 (void *)(__psint_t)(imapp->br_startoff),
134                 (void *)((unsigned long)(imapp->br_blockcount)),
135                 (void *)(__psint_t)(imapp->br_startblock));
136 }
137 #else
138 #define xfs_iomap_enter_trace(tag, io, offset, count)
139 #define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags)
140 #endif
141
142 #define XFS_WRITEIO_ALIGN(mp,off)       (((off) >> mp->m_writeio_log) \
143                                                 << mp->m_writeio_log)
144 #define XFS_STRAT_WRITE_IMAPS   2
145 #define XFS_WRITE_IMAPS         XFS_BMAP_MAX_NMAP
146
147 STATIC int
148 xfs_imap_to_bmap(
149         xfs_iocore_t    *io,
150         xfs_off_t       offset,
151         xfs_bmbt_irec_t *imap,
152         xfs_iomap_t     *iomapp,
153         int             imaps,                  /* Number of imap entries */
154         int             iomaps,                 /* Number of iomap entries */
155         int             flags)
156 {
157         xfs_mount_t     *mp;
158         xfs_fsize_t     nisize;
159         int             pbm;
160         xfs_fsblock_t   start_block;
161
162         mp = io->io_mount;
163         nisize = XFS_SIZE(mp, io);
164         if (io->io_new_size > nisize)
165                 nisize = io->io_new_size;
166
167         for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
168                 iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
169                 iomapp->iomap_delta = offset - iomapp->iomap_offset;
170                 iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
171                 iomapp->iomap_flags = flags;
172
173                 if (io->io_flags & XFS_IOCORE_RT) {
174                         iomapp->iomap_flags |= IOMAP_REALTIME;
175                         iomapp->iomap_target = mp->m_rtdev_targp;
176                 } else {
177                         iomapp->iomap_target = mp->m_ddev_targp;
178                 }
179                 start_block = imap->br_startblock;
180                 if (start_block == HOLESTARTBLOCK) {
181                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
182                         iomapp->iomap_flags |= IOMAP_HOLE;
183                 } else if (start_block == DELAYSTARTBLOCK) {
184                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
185                         iomapp->iomap_flags |= IOMAP_DELAY;
186                 } else {
187                         iomapp->iomap_bn = XFS_FSB_TO_DB_IO(io, start_block);
188                         if (ISUNWRITTEN(imap))
189                                 iomapp->iomap_flags |= IOMAP_UNWRITTEN;
190                 }
191
192                 if ((iomapp->iomap_offset + iomapp->iomap_bsize) >= nisize) {
193                         iomapp->iomap_flags |= IOMAP_EOF;
194                 }
195
196                 offset += iomapp->iomap_bsize - iomapp->iomap_delta;
197         }
198         return pbm;     /* Return the number filled */
199 }
200
201 int
202 xfs_iomap(
203         xfs_iocore_t    *io,
204         xfs_off_t       offset,
205         ssize_t         count,
206         int             flags,
207         xfs_iomap_t     *iomapp,
208         int             *niomaps)
209 {
210         xfs_mount_t     *mp = io->io_mount;
211         xfs_fileoff_t   offset_fsb, end_fsb;
212         int             error = 0;
213         int             lockmode = 0;
214         xfs_bmbt_irec_t imap;
215         int             nimaps = 1;
216         int             bmapi_flags = 0;
217         int             iomap_flags = 0;
218
219         if (XFS_FORCED_SHUTDOWN(mp))
220                 return XFS_ERROR(EIO);
221
222         switch (flags &
223                 (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE |
224                  BMAPI_UNWRITTEN | BMAPI_DEVICE)) {
225         case BMAPI_READ:
226                 xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, io, offset, count);
227                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
228                 bmapi_flags = XFS_BMAPI_ENTIRE;
229                 if (flags & BMAPI_IGNSTATE)
230                         bmapi_flags |= XFS_BMAPI_IGSTATE;
231                 break;
232         case BMAPI_WRITE:
233                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, io, offset, count);
234                 lockmode = XFS_ILOCK_EXCL|XFS_EXTSIZE_WR;
235                 bmapi_flags = 0;
236                 XFS_ILOCK(mp, io, lockmode);
237                 break;
238         case BMAPI_ALLOCATE:
239                 xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, io, offset, count);
240                 lockmode = XFS_ILOCK_SHARED|XFS_EXTSIZE_RD;
241                 bmapi_flags = XFS_BMAPI_ENTIRE;
242                 /* Attempt non-blocking lock */
243                 if (flags & BMAPI_TRYLOCK) {
244                         if (!XFS_ILOCK_NOWAIT(mp, io, lockmode))
245                                 return XFS_ERROR(EAGAIN);
246                 } else {
247                         XFS_ILOCK(mp, io, lockmode);
248                 }
249                 break;
250         case BMAPI_UNWRITTEN:
251                 goto phase2;
252         case BMAPI_DEVICE:
253                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
254                 iomapp->iomap_target = io->io_flags & XFS_IOCORE_RT ?
255                         mp->m_rtdev_targp : mp->m_ddev_targp;
256                 error = 0;
257                 *niomaps = 1;
258                 goto out;
259         default:
260                 BUG();
261         }
262
263         ASSERT(offset <= mp->m_maxioffset);
264         if ((xfs_fsize_t)offset + count > mp->m_maxioffset)
265                 count = mp->m_maxioffset - offset;
266         end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
267         offset_fsb = XFS_B_TO_FSBT(mp, offset);
268
269         error = XFS_BMAPI(mp, NULL, io, offset_fsb,
270                         (xfs_filblks_t)(end_fsb - offset_fsb),
271                         bmapi_flags,  NULL, 0, &imap,
272                         &nimaps, NULL);
273
274         if (error)
275                 goto out;
276
277 phase2:
278         switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE|BMAPI_UNWRITTEN)) {
279         case BMAPI_WRITE:
280                 /* If we found an extent, return it */
281                 if (nimaps &&
282                     (imap.br_startblock != HOLESTARTBLOCK) && 
283                     (imap.br_startblock != DELAYSTARTBLOCK)) {
284                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
285                                         offset, count, iomapp, &imap, flags);
286                         break;
287                 }
288
289                 if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
290                         error = XFS_IOMAP_WRITE_DIRECT(mp, io, offset,
291                                         count, flags, &imap, &nimaps, nimaps);
292                 } else {
293                         error = XFS_IOMAP_WRITE_DELAY(mp, io, offset, count,
294                                         flags, &imap, &nimaps);
295                 }
296                 if (!error) {
297                         xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, io,
298                                         offset, count, iomapp, &imap, flags);
299                 }
300                 iomap_flags = IOMAP_NEW;
301                 break;
302         case BMAPI_ALLOCATE:
303                 /* If we found an extent, return it */
304                 XFS_IUNLOCK(mp, io, lockmode);
305                 lockmode = 0;
306
307                 if (nimaps && !ISNULLSTARTBLOCK(imap.br_startblock)) {
308                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
309                                         offset, count, iomapp, &imap, flags);
310                         break;
311                 }
312
313                 error = XFS_IOMAP_WRITE_ALLOCATE(mp, io, offset, count,
314                                                  &imap, &nimaps);
315                 break;
316         case BMAPI_UNWRITTEN:
317                 lockmode = 0;
318                 error = XFS_IOMAP_WRITE_UNWRITTEN(mp, io, offset, count);
319                 nimaps = 0;
320                 break;
321         }
322
323         if (nimaps) {
324                 *niomaps = xfs_imap_to_bmap(io, offset, &imap,
325                                             iomapp, nimaps, *niomaps, iomap_flags);
326         } else if (niomaps) {
327                 *niomaps = 0;
328         }
329
330 out:
331         if (lockmode)
332                 XFS_IUNLOCK(mp, io, lockmode);
333         return XFS_ERROR(error);
334 }
335
336 STATIC int
337 xfs_flush_space(
338         xfs_inode_t     *ip,
339         int             *fsynced,
340         int             *ioflags)
341 {
342         switch (*fsynced) {
343         case 0:
344                 if (ip->i_delayed_blks) {
345                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
346                         xfs_flush_inode(ip);
347                         xfs_ilock(ip, XFS_ILOCK_EXCL);
348                         *fsynced = 1;
349                 } else {
350                         *ioflags |= BMAPI_SYNC;
351                         *fsynced = 2;
352                 }
353                 return 0;
354         case 1:
355                 *fsynced = 2;
356                 *ioflags |= BMAPI_SYNC;
357                 return 0;
358         case 2:
359                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
360                 xfs_flush_device(ip);
361                 xfs_ilock(ip, XFS_ILOCK_EXCL);
362                 *fsynced = 3;
363                 return 0;
364         }
365         return 1;
366 }
367
368 int
369 xfs_iomap_write_direct(
370         xfs_inode_t     *ip,
371         xfs_off_t       offset,
372         size_t          count,
373         int             flags,
374         xfs_bmbt_irec_t *ret_imap,
375         int             *nmaps,
376         int             found)
377 {
378         xfs_mount_t     *mp = ip->i_mount;
379         xfs_iocore_t    *io = &ip->i_iocore;
380         xfs_fileoff_t   offset_fsb;
381         xfs_fileoff_t   last_fsb;
382         xfs_filblks_t   count_fsb;
383         xfs_fsize_t     isize;
384         xfs_fsblock_t   firstfsb;
385         int             nimaps, maps;
386         int             error;
387         int             bmapi_flag;
388         int             rt;
389         xfs_trans_t     *tp;
390         xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS], *imapp;
391         xfs_bmap_free_t free_list;
392         int             aeof;
393         xfs_filblks_t   datablocks;
394         int             committed;
395         int             numrtextents;
396         uint            resblks;
397
398         /*
399          * Make sure that the dquots are there. This doesn't hold
400          * the ilock across a disk read.
401          */
402         error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
403         if (error)
404                 return XFS_ERROR(error);
405
406         maps = min(XFS_WRITE_IMAPS, *nmaps);
407         nimaps = maps;
408
409         isize = ip->i_d.di_size;
410         aeof = (offset + count) > isize;
411
412         if (io->io_new_size > isize)
413                 isize = io->io_new_size;
414
415         offset_fsb = XFS_B_TO_FSBT(mp, offset);
416         last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
417         count_fsb = last_fsb - offset_fsb;
418         if (found && (ret_imap->br_startblock == HOLESTARTBLOCK)) {
419                 xfs_fileoff_t   map_last_fsb;
420
421                 map_last_fsb = ret_imap->br_blockcount + ret_imap->br_startoff;
422
423                 if (map_last_fsb < last_fsb) {
424                         last_fsb = map_last_fsb;
425                         count_fsb = last_fsb - offset_fsb;
426                 }
427                 ASSERT(count_fsb > 0);
428         }
429
430         /*
431          * determine if reserving space on
432          * the data or realtime partition.
433          */
434         if ((rt = XFS_IS_REALTIME_INODE(ip))) {
435                 int     sbrtextsize, iprtextsize;
436
437                 sbrtextsize = mp->m_sb.sb_rextsize;
438                 iprtextsize =
439                         ip->i_d.di_extsize ? ip->i_d.di_extsize : sbrtextsize;
440                 numrtextents = (count_fsb + iprtextsize - 1);
441                 do_div(numrtextents, sbrtextsize);
442                 datablocks = 0;
443         } else {
444                 datablocks = count_fsb;
445                 numrtextents = 0;
446         }
447
448         /*
449          * allocate and setup the transaction
450          */
451         xfs_iunlock(ip, XFS_ILOCK_EXCL);
452         tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
453
454         resblks = XFS_DIOSTRAT_SPACE_RES(mp, datablocks);
455
456         error = xfs_trans_reserve(tp, resblks,
457                         XFS_WRITE_LOG_RES(mp), numrtextents,
458                         XFS_TRANS_PERM_LOG_RES,
459                         XFS_WRITE_LOG_COUNT);
460
461         /*
462          * check for running out of space
463          */
464         if (error)
465                 /*
466                  * Free the transaction structure.
467                  */
468                 xfs_trans_cancel(tp, 0);
469
470         xfs_ilock(ip, XFS_ILOCK_EXCL);
471
472         if (error)
473                 goto error_out; /* Don't return in above if .. trans ..,
474                                         need lock to return */
475
476         if (XFS_TRANS_RESERVE_BLKQUOTA(mp, tp, ip, resblks)) {
477                 error = (EDQUOT);
478                 goto error1;
479         }
480         nimaps = 1;
481
482         bmapi_flag = XFS_BMAPI_WRITE;
483         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
484         xfs_trans_ihold(tp, ip);
485
486         if (!(flags & BMAPI_MMAP) && (offset < ip->i_d.di_size || rt))
487                 bmapi_flag |= XFS_BMAPI_PREALLOC;
488
489         /*
490          * issue the bmapi() call to allocate the blocks
491          */
492         XFS_BMAP_INIT(&free_list, &firstfsb);
493         imapp = &imap[0];
494         error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
495                 bmapi_flag, &firstfsb, 0, imapp, &nimaps, &free_list);
496         if (error) {
497                 goto error0;
498         }
499
500         /*
501          * complete the transaction
502          */
503
504         error = xfs_bmap_finish(&tp, &free_list, firstfsb, &committed);
505         if (error) {
506                 goto error0;
507         }
508
509         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
510         if (error) {
511                 goto error_out;
512         }
513
514         /* copy any maps to caller's array and return any error. */
515         if (nimaps == 0) {
516                 error = (ENOSPC);
517                 goto error_out;
518         }
519
520         *ret_imap = imap[0];
521         *nmaps = 1;
522         if ( !(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
523                 cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
524                         "start_block : %llx start_off : %llx blkcnt : %llx "
525                         "extent-state : %x \n",
526                         (ip->i_mount)->m_fsname,
527                         (long long)ip->i_ino,
528                         ret_imap->br_startblock, ret_imap->br_startoff,
529                         ret_imap->br_blockcount,ret_imap->br_state);
530         }
531         return 0;
532
533  error0:        /* Cancel bmap, unlock inode, and cancel trans */
534         xfs_bmap_cancel(&free_list);
535
536  error1:        /* Just cancel transaction */
537         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
538         *nmaps = 0;     /* nothing set-up here */
539
540 error_out:
541         return XFS_ERROR(error);
542 }
543
544 int
545 xfs_iomap_write_delay(
546         xfs_inode_t     *ip,
547         xfs_off_t       offset,
548         size_t          count,
549         int             ioflag,
550         xfs_bmbt_irec_t *ret_imap,
551         int             *nmaps)
552 {
553         xfs_mount_t     *mp = ip->i_mount;
554         xfs_iocore_t    *io = &ip->i_iocore;
555         xfs_fileoff_t   offset_fsb;
556         xfs_fileoff_t   last_fsb;
557         xfs_fsize_t     isize;
558         xfs_fsblock_t   firstblock;
559         int             nimaps;
560         int             error;
561         xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
562         int             aeof;
563         int             fsynced = 0;
564
565         ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
566
567         /*
568          * Make sure that the dquots are there. This doesn't hold
569          * the ilock across a disk read.
570          */
571
572         error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
573         if (error)
574                 return XFS_ERROR(error);
575
576 retry:
577         isize = ip->i_d.di_size;
578         if (io->io_new_size > isize) {
579                 isize = io->io_new_size;
580         }
581
582         aeof = 0;
583         offset_fsb = XFS_B_TO_FSBT(mp, offset);
584         last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
585         /*
586          * If the caller is doing a write at the end of the file,
587          * then extend the allocation (and the buffer used for the write)
588          * out to the file system's write iosize.  We clean up any extra
589          * space left over when the file is closed in xfs_inactive().
590          *
591          * For sync writes, we are flushing delayed allocate space to
592          * try to make additional space available for allocation near
593          * the filesystem full boundary - preallocation hurts in that
594          * situation, of course.
595          */
596         if (!(ioflag & BMAPI_SYNC) && ((offset + count) > ip->i_d.di_size)) {
597                 xfs_off_t       aligned_offset;
598                 xfs_filblks_t   count_fsb;
599                 unsigned int    iosize;
600                 xfs_fileoff_t   ioalign;
601                 int             n;
602                 xfs_fileoff_t   start_fsb;
603
604                 /*
605                  * If there are any real blocks past eof, then don't
606                  * do any speculative allocation.
607                  */
608                 start_fsb = XFS_B_TO_FSBT(mp,
609                                         ((xfs_ufsize_t)(offset + count - 1)));
610                 count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
611                 while (count_fsb > 0) {
612                         nimaps = XFS_WRITE_IMAPS;
613                         error = XFS_BMAPI(mp, NULL, io, start_fsb, count_fsb,
614                                         0, &firstblock, 0, imap, &nimaps, NULL);
615                         if (error) {
616                                 return error;
617                         }
618                         for (n = 0; n < nimaps; n++) {
619                                 if ( !(io->io_flags & XFS_IOCORE_RT)  && 
620                                         !imap[n].br_startblock) {
621                                         cmn_err(CE_PANIC,"Access to block "
622                                                 "zero:  fs <%s> inode: %lld "
623                                                 "start_block : %llx start_off "
624                                                 ": %llx blkcnt : %llx "
625                                                 "extent-state : %x \n",
626                                                 (ip->i_mount)->m_fsname,
627                                                 (long long)ip->i_ino,
628                                                 imap[n].br_startblock,
629                                                 imap[n].br_startoff,
630                                                 imap[n].br_blockcount,
631                                                 imap[n].br_state);
632                                 }
633                                 if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
634                                     (imap[n].br_startblock != DELAYSTARTBLOCK)) {
635                                         goto write_map;
636                                 }
637                                 start_fsb += imap[n].br_blockcount;
638                                 count_fsb -= imap[n].br_blockcount;
639                         }
640                 }
641                 iosize = mp->m_writeio_blocks;
642                 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
643                 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
644                 last_fsb = ioalign + iosize;
645                 aeof = 1;
646         }
647 write_map:
648         nimaps = XFS_WRITE_IMAPS;
649         firstblock = NULLFSBLOCK;
650
651         /*
652          * If mounted with the "-o swalloc" option, roundup the allocation
653          * request to a stripe width boundary if the file size is >=
654          * stripe width and we are allocating past the allocation eof.
655          */
656         if (!(io->io_flags & XFS_IOCORE_RT) && mp->m_swidth 
657             && (mp->m_flags & XFS_MOUNT_SWALLOC)
658             && (isize >= XFS_FSB_TO_B(mp, mp->m_swidth)) && aeof) {
659                 int eof;
660                 xfs_fileoff_t new_last_fsb;
661
662                 new_last_fsb = roundup_64(last_fsb, mp->m_swidth);
663                 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
664                 if (error) {
665                         return error;
666                 }
667                 if (eof) {
668                         last_fsb = new_last_fsb;
669                 }
670         /*
671          * Roundup the allocation request to a stripe unit (m_dalign) boundary
672          * if the file size is >= stripe unit size, and we are allocating past
673          * the allocation eof.
674          */
675         } else if (!(io->io_flags & XFS_IOCORE_RT) && mp->m_dalign &&
676                    (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)) && aeof) {
677                 int eof;
678                 xfs_fileoff_t new_last_fsb;
679                 new_last_fsb = roundup_64(last_fsb, mp->m_dalign);
680                 error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof);
681                 if (error) {
682                         return error;
683                 }
684                 if (eof) {
685                         last_fsb = new_last_fsb;
686                 }
687         /*
688          * Round up the allocation request to a real-time extent boundary
689          * if the file is on the real-time subvolume.
690          */
691         } else if (io->io_flags & XFS_IOCORE_RT && aeof) {
692                 int eof;
693                 xfs_fileoff_t new_last_fsb;
694
695                 new_last_fsb = roundup_64(last_fsb, mp->m_sb.sb_rextsize);
696                 error = XFS_BMAP_EOF(mp, io, new_last_fsb, XFS_DATA_FORK, &eof);
697                 if (error) {
698                         return error;
699                 }
700                 if (eof)
701                         last_fsb = new_last_fsb;
702         }
703         error = xfs_bmapi(NULL, ip, offset_fsb,
704                           (xfs_filblks_t)(last_fsb - offset_fsb),
705                           XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
706                           XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
707                           &nimaps, NULL);
708         /*
709          * This can be EDQUOT, if nimaps == 0
710          */
711         if (error && (error != ENOSPC)) {
712                 return XFS_ERROR(error);
713         }
714         /*
715          * If bmapi returned us nothing, and if we didn't get back EDQUOT,
716          * then we must have run out of space.
717          */
718         if (nimaps == 0) {
719                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
720                                         io, offset, count);
721                 if (xfs_flush_space(ip, &fsynced, &ioflag))
722                         return XFS_ERROR(ENOSPC);
723
724                 error = 0;
725                 goto retry;
726         }
727
728         *ret_imap = imap[0];
729         *nmaps = 1;
730         if ( !(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
731                 cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
732                         "start_block : %llx start_off : %llx blkcnt : %llx "
733                         "extent-state : %x \n",
734                         (ip->i_mount)->m_fsname,
735                         (long long)ip->i_ino,
736                         ret_imap->br_startblock, ret_imap->br_startoff,
737                         ret_imap->br_blockcount,ret_imap->br_state);
738         }
739         return 0;
740 }
741
742 /*
743  * Pass in a delayed allocate extent, convert it to real extents;
744  * return to the caller the extent we create which maps on top of
745  * the originating callers request.
746  *
747  * Called without a lock on the inode.
748  */
749 int
750 xfs_iomap_write_allocate(
751         xfs_inode_t     *ip,
752         xfs_off_t       offset,
753         size_t          count,
754         xfs_bmbt_irec_t *map,
755         int             *retmap)
756 {
757         xfs_mount_t     *mp = ip->i_mount;
758         xfs_iocore_t    *io = &ip->i_iocore;
759         xfs_fileoff_t   offset_fsb, last_block;
760         xfs_fileoff_t   end_fsb, map_start_fsb;
761         xfs_fsblock_t   first_block;
762         xfs_bmap_free_t free_list;
763         xfs_filblks_t   count_fsb;
764         xfs_bmbt_irec_t imap[XFS_STRAT_WRITE_IMAPS];
765         xfs_trans_t     *tp;
766         int             i, nimaps, committed;
767         int             error = 0;
768         int             nres;
769
770         *retmap = 0;
771
772         /*
773          * Make sure that the dquots are there.
774          */
775         if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
776                 return XFS_ERROR(error);
777
778         offset_fsb = XFS_B_TO_FSBT(mp, offset);
779         count_fsb = map->br_blockcount;
780         map_start_fsb = map->br_startoff;
781
782         XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
783
784         while (count_fsb != 0) {
785                 /*
786                  * Set up a transaction with which to allocate the
787                  * backing store for the file.  Do allocations in a
788                  * loop until we get some space in the range we are
789                  * interested in.  The other space that might be allocated
790                  * is in the delayed allocation extent on which we sit
791                  * but before our buffer starts.
792                  */
793
794                 nimaps = 0;
795                 while (nimaps == 0) {
796                         tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
797                         nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
798                         error = xfs_trans_reserve(tp, nres,
799                                         XFS_WRITE_LOG_RES(mp),
800                                         0, XFS_TRANS_PERM_LOG_RES,
801                                         XFS_WRITE_LOG_COUNT);
802                         if (error == ENOSPC) {
803                                 error = xfs_trans_reserve(tp, 0,
804                                                 XFS_WRITE_LOG_RES(mp),
805                                                 0,
806                                                 XFS_TRANS_PERM_LOG_RES,
807                                                 XFS_WRITE_LOG_COUNT);
808                         }
809                         if (error) {
810                                 xfs_trans_cancel(tp, 0);
811                                 return XFS_ERROR(error);
812                         }
813                         xfs_ilock(ip, XFS_ILOCK_EXCL);
814                         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
815                         xfs_trans_ihold(tp, ip);
816
817                         XFS_BMAP_INIT(&free_list, &first_block);
818
819                         nimaps = XFS_STRAT_WRITE_IMAPS;
820                         /*
821                          * Ensure we don't go beyond eof - it is possible
822                          * the extents changed since we did the read call,
823                          * we dropped the ilock in the interim.
824                          */
825
826                         end_fsb = XFS_B_TO_FSB(mp, ip->i_d.di_size);
827                         xfs_bmap_last_offset(NULL, ip, &last_block,
828                                 XFS_DATA_FORK);
829                         last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
830                         if ((map_start_fsb + count_fsb) > last_block) {
831                                 count_fsb = last_block - map_start_fsb;
832                                 if (count_fsb == 0) {
833                                         error = EAGAIN;
834                                         goto trans_cancel;
835                                 }
836                         }
837
838                         /* Go get the actual blocks */
839                         error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
840                                         XFS_BMAPI_WRITE, &first_block, 1,
841                                         imap, &nimaps, &free_list);
842                         if (error)
843                                 goto trans_cancel;
844
845                         error = xfs_bmap_finish(&tp, &free_list,
846                                         first_block, &committed);
847                         if (error)
848                                 goto trans_cancel;
849
850                         error = xfs_trans_commit(tp,
851                                         XFS_TRANS_RELEASE_LOG_RES, NULL);
852                         if (error)
853                                 goto error0;
854
855                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
856                 }
857
858                 /*
859                  * See if we were able to allocate an extent that
860                  * covers at least part of the callers request
861                  */
862
863                 for (i = 0; i < nimaps; i++) {
864                         if ( !(io->io_flags & XFS_IOCORE_RT)  && 
865                                 !imap[i].br_startblock) {
866                                 cmn_err(CE_PANIC,"Access to block zero:  "
867                                         "fs <%s> inode: %lld "
868                                         "start_block : %llx start_off : %llx " 
869                                         "blkcnt : %llx extent-state : %x \n",
870                                         (ip->i_mount)->m_fsname,
871                                         (long long)ip->i_ino,
872                                         imap[i].br_startblock,
873                                         imap[i].br_startoff,
874                                         imap[i].br_blockcount,imap[i].br_state);
875                         }
876                         if ((offset_fsb >= imap[i].br_startoff) &&
877                             (offset_fsb < (imap[i].br_startoff +
878                                            imap[i].br_blockcount))) {
879                                 *map = imap[i];
880                                 *retmap = 1;
881                                 XFS_STATS_INC(xs_xstrat_quick);
882                                 return 0;
883                         }
884                         count_fsb -= imap[i].br_blockcount;
885                 }
886
887                 /* So far we have not mapped the requested part of the
888                  * file, just surrounding data, try again.
889                  */
890                 nimaps--;
891                 map_start_fsb = imap[nimaps].br_startoff +
892                                 imap[nimaps].br_blockcount;
893         }
894
895 trans_cancel:
896         xfs_bmap_cancel(&free_list);
897         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
898 error0:
899         xfs_iunlock(ip, XFS_ILOCK_EXCL);
900         return XFS_ERROR(error);
901 }
902
903 int
904 xfs_iomap_write_unwritten(
905         xfs_inode_t     *ip,
906         xfs_off_t       offset,
907         size_t          count)
908 {
909         xfs_mount_t     *mp = ip->i_mount;
910         xfs_iocore_t    *io = &ip->i_iocore;
911         xfs_trans_t     *tp;
912         xfs_fileoff_t   offset_fsb;
913         xfs_filblks_t   count_fsb;
914         xfs_filblks_t   numblks_fsb;
915         xfs_bmbt_irec_t imap;
916         int             committed;
917         int             error;
918         int             nres;
919         int             nimaps;
920         xfs_fsblock_t   firstfsb;
921         xfs_bmap_free_t free_list;
922
923         xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN,
924                                 &ip->i_iocore, offset, count);
925
926         offset_fsb = XFS_B_TO_FSBT(mp, offset);
927         count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
928         count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
929
930         do {
931                 nres = XFS_DIOSTRAT_SPACE_RES(mp, 0);
932
933                 /*
934                  * set up a transaction to convert the range of extents
935                  * from unwritten to real. Do allocations in a loop until
936                  * we have covered the range passed in.
937                  */
938
939                 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
940                 error = xfs_trans_reserve(tp, nres,
941                                 XFS_WRITE_LOG_RES(mp), 0,
942                                 XFS_TRANS_PERM_LOG_RES,
943                                 XFS_WRITE_LOG_COUNT);
944                 if (error) {
945                         xfs_trans_cancel(tp, 0);
946                         goto error0;
947                 }
948
949                 xfs_ilock(ip, XFS_ILOCK_EXCL);
950                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
951                 xfs_trans_ihold(tp, ip);
952
953                 /*
954                  * Modify the unwritten extent state of the buffer.
955                  */
956                 XFS_BMAP_INIT(&free_list, &firstfsb);
957                 nimaps = 1;
958                 error = xfs_bmapi(tp, ip, offset_fsb, count_fsb,
959                                   XFS_BMAPI_WRITE, &firstfsb,
960                                   1, &imap, &nimaps, &free_list);
961                 if (error)
962                         goto error_on_bmapi_transaction;
963
964                 error = xfs_bmap_finish(&(tp), &(free_list),
965                                 firstfsb, &committed);
966                 if (error)
967                         goto error_on_bmapi_transaction;
968
969                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
970                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
971                 if (error)
972                         goto error0;
973                 
974                 if ( !(io->io_flags & XFS_IOCORE_RT)  && !imap.br_startblock) {
975                         cmn_err(CE_PANIC,"Access to block zero:  fs <%s> "
976                                 "inode: %lld start_block : %llx start_off : "
977                                 "%llx blkcnt : %llx extent-state : %x \n",
978                                 (ip->i_mount)->m_fsname,
979                                 (long long)ip->i_ino,
980                                 imap.br_startblock,imap.br_startoff,
981                                 imap.br_blockcount,imap.br_state);
982                 }
983
984                 if ((numblks_fsb = imap.br_blockcount) == 0) {
985                         /*
986                          * The numblks_fsb value should always get
987                          * smaller, otherwise the loop is stuck.
988                          */
989                         ASSERT(imap.br_blockcount);
990                         break;
991                 }
992                 offset_fsb += numblks_fsb;
993                 count_fsb -= numblks_fsb;
994         } while (count_fsb > 0);
995
996         return 0;
997
998 error_on_bmapi_transaction:
999         xfs_bmap_cancel(&free_list);
1000         xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
1001         xfs_iunlock(ip, XFS_ILOCK_EXCL);
1002 error0:
1003         return XFS_ERROR(error);
1004 }