[XFS] Fixing KDB's xrwtrc command, also added the current process id into
[linux-2.6.git] / 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_rtalloc.h"
44 #include "xfs_error.h"
45 #include "xfs_itable.h"
46 #include "xfs_rw.h"
47 #include "xfs_acl.h"
48 #include "xfs_cap.h"
49 #include "xfs_mac.h"
50 #include "xfs_attr.h"
51 #include "xfs_buf_item.h"
52 #include "xfs_trans_space.h"
53 #include "xfs_utils.h"
54 #include "xfs_iomap.h"
55
56 #if defined(XFS_RW_TRACE)
57 void
58 xfs_iomap_enter_trace(
59         int             tag,
60         xfs_iocore_t    *io,
61         xfs_off_t       offset,
62         ssize_t         count)
63 {
64         xfs_inode_t     *ip = XFS_IO_INODE(io);
65
66         if (!ip->i_rwtrace)
67                 return;
68
69         ktrace_enter(ip->i_rwtrace,
70                 (void *)((unsigned long)tag),
71                 (void *)ip,
72                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
73                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
74                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
75                 (void *)((unsigned long)(offset & 0xffffffff)),
76                 (void *)((unsigned long)count),
77                 (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
78                 (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
79                 (void *)((unsigned long)current_pid()),
80                 (void *)NULL,
81                 (void *)NULL,
82                 (void *)NULL,
83                 (void *)NULL,
84                 (void *)NULL,
85                 (void *)NULL);
86 }
87
88 void
89 xfs_iomap_map_trace(
90         int             tag,
91         xfs_iocore_t    *io,
92         xfs_off_t       offset,
93         ssize_t         count,
94         xfs_iomap_t     *iomapp,
95         xfs_bmbt_irec_t *imapp,
96         int             flags)
97 {
98         xfs_inode_t     *ip = XFS_IO_INODE(io);
99
100         if (!ip->i_rwtrace)
101                 return;
102
103         ktrace_enter(ip->i_rwtrace,
104                 (void *)((unsigned long)tag),
105                 (void *)ip,
106                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
107                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
108                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
109                 (void *)((unsigned long)(offset & 0xffffffff)),
110                 (void *)((unsigned long)count),
111                 (void *)((unsigned long)flags),
112                 (void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)),
113                 (void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)),
114                 (void *)((unsigned long)(iomapp->iomap_delta)),
115                 (void *)((unsigned long)(iomapp->iomap_bsize)),
116                 (void *)((unsigned long)(iomapp->iomap_bn)),
117                 (void *)(__psint_t)(imapp->br_startoff),
118                 (void *)((unsigned long)(imapp->br_blockcount)),
119                 (void *)(__psint_t)(imapp->br_startblock));
120 }
121 #else
122 #define xfs_iomap_enter_trace(tag, io, offset, count)
123 #define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags)
124 #endif
125
126 #define XFS_WRITEIO_ALIGN(mp,off)       (((off) >> mp->m_writeio_log) \
127                                                 << mp->m_writeio_log)
128 #define XFS_STRAT_WRITE_IMAPS   2
129 #define XFS_WRITE_IMAPS         XFS_BMAP_MAX_NMAP
130
131 STATIC int
132 xfs_imap_to_bmap(
133         xfs_iocore_t    *io,
134         xfs_off_t       offset,
135         xfs_bmbt_irec_t *imap,
136         xfs_iomap_t     *iomapp,
137         int             imaps,                  /* Number of imap entries */
138         int             iomaps,                 /* Number of iomap entries */
139         int             flags)
140 {
141         xfs_mount_t     *mp;
142         xfs_fsize_t     nisize;
143         int             pbm;
144         xfs_fsblock_t   start_block;
145
146         mp = io->io_mount;
147         nisize = XFS_SIZE(mp, io);
148         if (io->io_new_size > nisize)
149                 nisize = io->io_new_size;
150
151         for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
152                 iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
153                 iomapp->iomap_delta = offset - iomapp->iomap_offset;
154                 iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
155                 iomapp->iomap_flags = flags;
156
157                 if (io->io_flags & XFS_IOCORE_RT) {
158                         iomapp->iomap_flags |= IOMAP_REALTIME;
159                         iomapp->iomap_target = mp->m_rtdev_targp;
160                 } else {
161                         iomapp->iomap_target = mp->m_ddev_targp;
162                 }
163                 start_block = imap->br_startblock;
164                 if (start_block == HOLESTARTBLOCK) {
165                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
166                         iomapp->iomap_flags |= IOMAP_HOLE;
167                 } else if (start_block == DELAYSTARTBLOCK) {
168                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
169                         iomapp->iomap_flags |= IOMAP_DELAY;
170                 } else {
171                         iomapp->iomap_bn = XFS_FSB_TO_DB_IO(io, start_block);
172                         if (ISUNWRITTEN(imap))
173                                 iomapp->iomap_flags |= IOMAP_UNWRITTEN;
174                 }
175
176                 if ((iomapp->iomap_offset + iomapp->iomap_bsize) >= nisize) {
177                         iomapp->iomap_flags |= IOMAP_EOF;
178                 }
179
180                 offset += iomapp->iomap_bsize - iomapp->iomap_delta;
181         }
182         return pbm;     /* Return the number filled */
183 }
184
185 int
186 xfs_iomap(
187         xfs_iocore_t    *io,
188         xfs_off_t       offset,
189         ssize_t         count,
190         int             flags,
191         xfs_iomap_t     *iomapp,
192         int             *niomaps)
193 {
194         xfs_mount_t     *mp = io->io_mount;
195         xfs_fileoff_t   offset_fsb, end_fsb;
196         int             error = 0;
197         int             lockmode = 0;
198         xfs_bmbt_irec_t imap;
199         int             nimaps = 1;
200         int             bmapi_flags = 0;
201         int             iomap_flags = 0;
202
203         if (XFS_FORCED_SHUTDOWN(mp))
204                 return XFS_ERROR(EIO);
205
206         switch (flags &
207                 (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE |
208                  BMAPI_UNWRITTEN | BMAPI_DEVICE)) {
209         case BMAPI_READ:
210                 xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, io, offset, count);
211                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
212                 bmapi_flags = XFS_BMAPI_ENTIRE;
213                 break;
214         case BMAPI_WRITE:
215                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, io, offset, count);
216                 lockmode = XFS_ILOCK_EXCL|XFS_EXTSIZE_WR;
217                 if (flags & BMAPI_IGNSTATE)
218                         bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE;
219                 XFS_ILOCK(mp, io, lockmode);
220                 break;
221         case BMAPI_ALLOCATE:
222                 xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, io, offset, count);
223                 lockmode = XFS_ILOCK_SHARED|XFS_EXTSIZE_RD;
224                 bmapi_flags = XFS_BMAPI_ENTIRE;
225                 /* Attempt non-blocking lock */
226                 if (flags & BMAPI_TRYLOCK) {
227                         if (!XFS_ILOCK_NOWAIT(mp, io, lockmode))
228                                 return XFS_ERROR(EAGAIN);
229                 } else {
230                         XFS_ILOCK(mp, io, lockmode);
231                 }
232                 break;
233         case BMAPI_UNWRITTEN:
234                 goto phase2;
235         case BMAPI_DEVICE:
236                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
237                 iomapp->iomap_target = io->io_flags & XFS_IOCORE_RT ?
238                         mp->m_rtdev_targp : mp->m_ddev_targp;
239                 error = 0;
240                 *niomaps = 1;
241                 goto out;
242         default:
243                 BUG();
244         }
245
246         ASSERT(offset <= mp->m_maxioffset);
247         if ((xfs_fsize_t)offset + count > mp->m_maxioffset)
248                 count = mp->m_maxioffset - offset;
249         end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
250         offset_fsb = XFS_B_TO_FSBT(mp, offset);
251
252         error = XFS_BMAPI(mp, NULL, io, offset_fsb,
253                         (xfs_filblks_t)(end_fsb - offset_fsb),
254                         bmapi_flags,  NULL, 0, &imap,
255                         &nimaps, NULL);
256
257         if (error)
258                 goto out;
259
260 phase2:
261         switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE|BMAPI_UNWRITTEN)) {
262         case BMAPI_WRITE:
263                 /* If we found an extent, return it */
264                 if (nimaps &&
265                     (imap.br_startblock != HOLESTARTBLOCK) &&
266                     (imap.br_startblock != DELAYSTARTBLOCK)) {
267                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
268                                         offset, count, iomapp, &imap, flags);
269                         break;
270                 }
271
272                 if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
273                         error = XFS_IOMAP_WRITE_DIRECT(mp, io, offset,
274                                         count, flags, &imap, &nimaps, nimaps);
275                 } else {
276                         error = XFS_IOMAP_WRITE_DELAY(mp, io, offset, count,
277                                         flags, &imap, &nimaps);
278                 }
279                 if (!error) {
280                         xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, io,
281                                         offset, count, iomapp, &imap, flags);
282                 }
283                 iomap_flags = IOMAP_NEW;
284                 break;
285         case BMAPI_ALLOCATE:
286                 /* If we found an extent, return it */
287                 XFS_IUNLOCK(mp, io, lockmode);
288                 lockmode = 0;
289
290                 if (nimaps && !ISNULLSTARTBLOCK(imap.br_startblock)) {
291                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
292                                         offset, count, iomapp, &imap, flags);
293                         break;
294                 }
295
296                 error = XFS_IOMAP_WRITE_ALLOCATE(mp, io, offset, count,
297                                                  &imap, &nimaps);
298                 break;
299         case BMAPI_UNWRITTEN:
300                 lockmode = 0;
301                 error = XFS_IOMAP_WRITE_UNWRITTEN(mp, io, offset, count);
302                 nimaps = 0;
303                 break;
304         }
305
306         if (nimaps) {
307                 *niomaps = xfs_imap_to_bmap(io, offset, &imap,
308                                             iomapp, nimaps, *niomaps, iomap_flags);
309         } else if (niomaps) {
310                 *niomaps = 0;
311         }
312
313 out:
314         if (lockmode)
315                 XFS_IUNLOCK(mp, io, lockmode);
316         return XFS_ERROR(error);
317 }
318
319 STATIC int
320 xfs_iomap_eof_align_last_fsb(
321         xfs_mount_t     *mp,
322         xfs_iocore_t    *io,
323         xfs_fsize_t     isize,
324         xfs_extlen_t    extsize,
325         xfs_fileoff_t   *last_fsb)
326 {
327         xfs_fileoff_t   new_last_fsb = 0;
328         xfs_extlen_t    align;
329         int             eof, error;
330
331         if (io->io_flags & XFS_IOCORE_RT)
332                 ;
333         /*
334          * If mounted with the "-o swalloc" option, roundup the allocation
335          * request to a stripe width boundary if the file size is >=
336          * stripe width and we are allocating past the allocation eof.
337          */
338         else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) &&
339                 (isize >= XFS_FSB_TO_B(mp, mp->m_swidth)))
340                 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth);
341         /*
342          * Roundup the allocation request to a stripe unit (m_dalign) boundary
343          * if the file size is >= stripe unit size, and we are allocating past
344          * the allocation eof.
345          */
346         else if (mp->m_dalign && (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)))
347                 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign);
348
349         /*
350          * Always round up the allocation request to an extent boundary
351          * (when file on a real-time subvolume or has di_extsize hint).
352          */
353         if (extsize) {
354                 if (new_last_fsb)
355                         align = roundup_64(new_last_fsb, extsize);
356                 else
357                         align = extsize;
358                 new_last_fsb = roundup_64(*last_fsb, align);
359         }
360
361         if (new_last_fsb) {
362                 error = XFS_BMAP_EOF(mp, io, new_last_fsb, XFS_DATA_FORK, &eof);
363                 if (error)
364                         return error;
365                 if (eof)
366                         *last_fsb = new_last_fsb;
367         }
368         return 0;
369 }
370
371 STATIC int
372 xfs_flush_space(
373         xfs_inode_t     *ip,
374         int             *fsynced,
375         int             *ioflags)
376 {
377         switch (*fsynced) {
378         case 0:
379                 if (ip->i_delayed_blks) {
380                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
381                         xfs_flush_inode(ip);
382                         xfs_ilock(ip, XFS_ILOCK_EXCL);
383                         *fsynced = 1;
384                 } else {
385                         *ioflags |= BMAPI_SYNC;
386                         *fsynced = 2;
387                 }
388                 return 0;
389         case 1:
390                 *fsynced = 2;
391                 *ioflags |= BMAPI_SYNC;
392                 return 0;
393         case 2:
394                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
395                 xfs_flush_device(ip);
396                 xfs_ilock(ip, XFS_ILOCK_EXCL);
397                 *fsynced = 3;
398                 return 0;
399         }
400         return 1;
401 }
402
403 int
404 xfs_iomap_write_direct(
405         xfs_inode_t     *ip,
406         xfs_off_t       offset,
407         size_t          count,
408         int             flags,
409         xfs_bmbt_irec_t *ret_imap,
410         int             *nmaps,
411         int             found)
412 {
413         xfs_mount_t     *mp = ip->i_mount;
414         xfs_iocore_t    *io = &ip->i_iocore;
415         xfs_fileoff_t   offset_fsb;
416         xfs_fileoff_t   last_fsb;
417         xfs_filblks_t   count_fsb, resaligned;
418         xfs_fsblock_t   firstfsb;
419         xfs_extlen_t    extsz, temp;
420         xfs_fsize_t     isize;
421         int             nimaps;
422         int             bmapi_flag;
423         int             quota_flag;
424         int             rt;
425         xfs_trans_t     *tp;
426         xfs_bmbt_irec_t imap;
427         xfs_bmap_free_t free_list;
428         uint            qblocks, resblks, resrtextents;
429         int             committed;
430         int             error;
431
432         /*
433          * Make sure that the dquots are there. This doesn't hold
434          * the ilock across a disk read.
435          */
436         error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
437         if (error)
438                 return XFS_ERROR(error);
439
440         rt = XFS_IS_REALTIME_INODE(ip);
441         if (unlikely(rt)) {
442                 if (!(extsz = ip->i_d.di_extsize))
443                         extsz = mp->m_sb.sb_rextsize;
444         } else {
445                 extsz = ip->i_d.di_extsize;
446         }
447
448         isize = ip->i_d.di_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_d.di_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(tp, ip, offset_fsb, count_fsb,
523                 bmapi_flag, &firstfsb, 0, &imap, &nimaps, &free_list);
524         if (error)
525                 goto error0;
526
527         /*
528          * Complete the transaction
529          */
530         error = xfs_bmap_finish(&tp, &free_list, firstfsb, &committed);
531         if (error)
532                 goto error0;
533         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
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         *ret_imap = imap;
546         *nmaps = 1;
547         if ( !(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
548                 cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
549                         "start_block : %llx start_off : %llx blkcnt : %llx "
550                         "extent-state : %x \n",
551                         (ip->i_mount)->m_fsname,
552                         (long long)ip->i_ino,
553                         (unsigned long long)ret_imap->br_startblock,
554                         (unsigned long long)ret_imap->br_startoff,
555                         (unsigned long long)ret_imap->br_blockcount,
556                         ret_imap->br_state);
557         }
558         return 0;
559
560 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
561         xfs_bmap_cancel(&free_list);
562         XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
563
564 error1: /* Just cancel transaction */
565         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
566         *nmaps = 0;     /* nothing set-up here */
567
568 error_out:
569         return XFS_ERROR(error);
570 }
571
572 /*
573  * If the caller is doing a write at the end of the file,
574  * then extend the allocation out to the file system's write
575  * iosize.  We clean up any extra space left over when the
576  * file is closed in xfs_inactive().
577  *
578  * For sync writes, we are flushing delayed allocate space to
579  * try to make additional space available for allocation near
580  * the filesystem full boundary - preallocation hurts in that
581  * situation, of course.
582  */
583 STATIC int
584 xfs_iomap_eof_want_preallocate(
585         xfs_mount_t     *mp,
586         xfs_iocore_t    *io,
587         xfs_fsize_t     isize,
588         xfs_off_t       offset,
589         size_t          count,
590         int             ioflag,
591         xfs_bmbt_irec_t *imap,
592         int             nimaps,
593         int             *prealloc)
594 {
595         xfs_fileoff_t   start_fsb;
596         xfs_filblks_t   count_fsb;
597         xfs_fsblock_t   firstblock;
598         int             n, error, imaps;
599
600         *prealloc = 0;
601         if ((ioflag & BMAPI_SYNC) || (offset + count) <= isize)
602                 return 0;
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, ((xfs_ufsize_t)(offset + count - 1)));
609         count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
610         while (count_fsb > 0) {
611                 imaps = nimaps;
612                 firstblock = NULLFSBLOCK;
613                 error = XFS_BMAPI(mp, NULL, io, start_fsb, count_fsb,
614                                   0, &firstblock, 0, imap, &imaps, NULL);
615                 if (error)
616                         return error;
617                 for (n = 0; n < imaps; n++) {
618                         if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
619                             (imap[n].br_startblock != DELAYSTARTBLOCK))
620                                 return 0;
621                         start_fsb += imap[n].br_blockcount;
622                         count_fsb -= imap[n].br_blockcount;
623                 }
624         }
625         *prealloc = 1;
626         return 0;
627 }
628
629 int
630 xfs_iomap_write_delay(
631         xfs_inode_t     *ip,
632         xfs_off_t       offset,
633         size_t          count,
634         int             ioflag,
635         xfs_bmbt_irec_t *ret_imap,
636         int             *nmaps)
637 {
638         xfs_mount_t     *mp = ip->i_mount;
639         xfs_iocore_t    *io = &ip->i_iocore;
640         xfs_fileoff_t   offset_fsb;
641         xfs_fileoff_t   last_fsb;
642         xfs_off_t       aligned_offset;
643         xfs_fileoff_t   ioalign;
644         xfs_fsblock_t   firstblock;
645         xfs_extlen_t    extsz;
646         xfs_fsize_t     isize;
647         int             nimaps;
648         xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
649         int             prealloc, fsynced = 0;
650         int             error;
651
652         ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
653
654         /*
655          * Make sure that the dquots are there. This doesn't hold
656          * the ilock across a disk read.
657          */
658         error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
659         if (error)
660                 return XFS_ERROR(error);
661
662         if (XFS_IS_REALTIME_INODE(ip)) {
663                 if (!(extsz = ip->i_d.di_extsize))
664                         extsz = mp->m_sb.sb_rextsize;
665         } else {
666                 extsz = ip->i_d.di_extsize;
667         }
668
669         offset_fsb = XFS_B_TO_FSBT(mp, offset);
670
671 retry:
672         isize = ip->i_d.di_size;
673         if (io->io_new_size > isize)
674                 isize = io->io_new_size;
675
676         error = xfs_iomap_eof_want_preallocate(mp, io, isize, offset, count,
677                                 ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
678         if (error)
679                 return error;
680
681         if (prealloc) {
682                 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
683                 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
684                 last_fsb = ioalign + mp->m_writeio_blocks;
685         } else {
686                 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
687         }
688
689         if (prealloc || extsz) {
690                 error = xfs_iomap_eof_align_last_fsb(mp, io, isize, extsz,
691                                                         &last_fsb);
692                 if (error)
693                         return error;
694         }
695
696         nimaps = XFS_WRITE_IMAPS;
697         firstblock = NULLFSBLOCK;
698         error = xfs_bmapi(NULL, ip, offset_fsb,
699                           (xfs_filblks_t)(last_fsb - offset_fsb),
700                           XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
701                           XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
702                           &nimaps, NULL);
703         if (error && (error != ENOSPC))
704                 return XFS_ERROR(error);
705
706         /*
707          * If bmapi returned us nothing, and if we didn't get back EDQUOT,
708          * then we must have run out of space - flush delalloc, and retry..
709          */
710         if (nimaps == 0) {
711                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
712                                         io, offset, count);
713                 if (xfs_flush_space(ip, &fsynced, &ioflag))
714                         return XFS_ERROR(ENOSPC);
715
716                 error = 0;
717                 goto retry;
718         }
719
720         if (!(io->io_flags & XFS_IOCORE_RT)  && !ret_imap->br_startblock) {
721                 cmn_err(CE_PANIC,"Access to block zero:  fs <%s> inode: %lld "
722                         "start_block : %llx start_off : %llx blkcnt : %llx "
723                         "extent-state : %x \n",
724                         (ip->i_mount)->m_fsname,
725                         (long long)ip->i_ino,
726                         (unsigned long long)ret_imap->br_startblock,
727                         (unsigned long long)ret_imap->br_startoff,
728                         (unsigned long long)ret_imap->br_blockcount,
729                         ret_imap->br_state);
730         }
731
732         *ret_imap = imap[0];
733         *nmaps = 1;
734
735         return 0;
736 }
737
738 /*
739  * Pass in a delayed allocate extent, convert it to real extents;
740  * return to the caller the extent we create which maps on top of
741  * the originating callers request.
742  *
743  * Called without a lock on the inode.
744  */
745 int
746 xfs_iomap_write_allocate(
747         xfs_inode_t     *ip,
748         xfs_off_t       offset,
749         size_t          count,
750         xfs_bmbt_irec_t *map,
751         int             *retmap)
752 {
753         xfs_mount_t     *mp = ip->i_mount;
754         xfs_iocore_t    *io = &ip->i_iocore;
755         xfs_fileoff_t   offset_fsb, last_block;
756         xfs_fileoff_t   end_fsb, map_start_fsb;
757         xfs_fsblock_t   first_block;
758         xfs_bmap_free_t free_list;
759         xfs_filblks_t   count_fsb;
760         xfs_bmbt_irec_t imap[XFS_STRAT_WRITE_IMAPS];
761         xfs_trans_t     *tp;
762         int             i, nimaps, committed;
763         int             error = 0;
764         int             nres;
765
766         *retmap = 0;
767
768         /*
769          * Make sure that the dquots are there.
770          */
771         if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
772                 return XFS_ERROR(error);
773
774         offset_fsb = XFS_B_TO_FSBT(mp, offset);
775         count_fsb = map->br_blockcount;
776         map_start_fsb = map->br_startoff;
777
778         XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
779
780         while (count_fsb != 0) {
781                 /*
782                  * Set up a transaction with which to allocate the
783                  * backing store for the file.  Do allocations in a
784                  * loop until we get some space in the range we are
785                  * interested in.  The other space that might be allocated
786                  * is in the delayed allocation extent on which we sit
787                  * but before our buffer starts.
788                  */
789
790                 nimaps = 0;
791                 while (nimaps == 0) {
792                         tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
793                         nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
794                         error = xfs_trans_reserve(tp, nres,
795                                         XFS_WRITE_LOG_RES(mp),
796                                         0, XFS_TRANS_PERM_LOG_RES,
797                                         XFS_WRITE_LOG_COUNT);
798                         if (error == ENOSPC) {
799                                 error = xfs_trans_reserve(tp, 0,
800                                                 XFS_WRITE_LOG_RES(mp),
801                                                 0,
802                                                 XFS_TRANS_PERM_LOG_RES,
803                                                 XFS_WRITE_LOG_COUNT);
804                         }
805                         if (error) {
806                                 xfs_trans_cancel(tp, 0);
807                                 return XFS_ERROR(error);
808                         }
809                         xfs_ilock(ip, XFS_ILOCK_EXCL);
810                         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
811                         xfs_trans_ihold(tp, ip);
812
813                         XFS_BMAP_INIT(&free_list, &first_block);
814
815                         nimaps = XFS_STRAT_WRITE_IMAPS;
816                         /*
817                          * Ensure we don't go beyond eof - it is possible
818                          * the extents changed since we did the read call,
819                          * we dropped the ilock in the interim.
820                          */
821
822                         end_fsb = XFS_B_TO_FSB(mp, ip->i_d.di_size);
823                         xfs_bmap_last_offset(NULL, ip, &last_block,
824                                 XFS_DATA_FORK);
825                         last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
826                         if ((map_start_fsb + count_fsb) > last_block) {
827                                 count_fsb = last_block - map_start_fsb;
828                                 if (count_fsb == 0) {
829                                         error = EAGAIN;
830                                         goto trans_cancel;
831                                 }
832                         }
833
834                         /* Go get the actual blocks */
835                         error = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
836                                         XFS_BMAPI_WRITE, &first_block, 1,
837                                         imap, &nimaps, &free_list);
838                         if (error)
839                                 goto trans_cancel;
840
841                         error = xfs_bmap_finish(&tp, &free_list,
842                                         first_block, &committed);
843                         if (error)
844                                 goto trans_cancel;
845
846                         error = xfs_trans_commit(tp,
847                                         XFS_TRANS_RELEASE_LOG_RES, NULL);
848                         if (error)
849                                 goto error0;
850
851                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
852                 }
853
854                 /*
855                  * See if we were able to allocate an extent that
856                  * covers at least part of the callers request
857                  */
858
859                 for (i = 0; i < nimaps; i++) {
860                         if (!(io->io_flags & XFS_IOCORE_RT)  &&
861                             !imap[i].br_startblock) {
862                                 cmn_err(CE_PANIC,"Access to block zero:  "
863                                         "fs <%s> inode: %lld "
864                                         "start_block : %llx start_off : %llx "
865                                         "blkcnt : %llx extent-state : %x \n",
866                                         (ip->i_mount)->m_fsname,
867                                         (long long)ip->i_ino,
868                                         (unsigned long long)
869                                                 imap[i].br_startblock,
870                                         (unsigned long long)
871                                                 imap[i].br_startoff,
872                                         (unsigned long long)
873                                                 imap[i].br_blockcount,
874                                         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_fileoff_t   offset_fsb;
912         xfs_filblks_t   count_fsb;
913         xfs_filblks_t   numblks_fsb;
914         xfs_fsblock_t   firstfsb;
915         int             nimaps;
916         xfs_trans_t     *tp;
917         xfs_bmbt_irec_t imap;
918         xfs_bmap_free_t free_list;
919         uint            resblks;
920         int             committed;
921         int             error;
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         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
931
932         do {
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, resblks,
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|XFS_BMAPI_CONVERT, &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                                 (unsigned long long)imap.br_startblock,
981                                 (unsigned long long)imap.br_startoff,
982                                 (unsigned long long)imap.br_blockcount,
983                                 imap.br_state);
984                 }
985
986                 if ((numblks_fsb = imap.br_blockcount) == 0) {
987                         /*
988                          * The numblks_fsb value should always get
989                          * smaller, otherwise the loop is stuck.
990                          */
991                         ASSERT(imap.br_blockcount);
992                         break;
993                 }
994                 offset_fsb += numblks_fsb;
995                 count_fsb -= numblks_fsb;
996         } while (count_fsb > 0);
997
998         return 0;
999
1000 error_on_bmapi_transaction:
1001         xfs_bmap_cancel(&free_list);
1002         xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
1003         xfs_iunlock(ip, XFS_ILOCK_EXCL);
1004 error0:
1005         return XFS_ERROR(error);
1006 }