git.oblomov.eu Git - linux-2.6/blob - fs/xfs/xfs_iomap.c

   1 /*
   2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_fs.h"
  20 #include "xfs_bit.h"
  21 #include "xfs_log.h"
  22 #include "xfs_inum.h"
  23 #include "xfs_trans.h"
  24 #include "xfs_sb.h"
  25 #include "xfs_ag.h"
  26 #include "xfs_dir2.h"
  27 #include "xfs_alloc.h"
  28 #include "xfs_dmapi.h"
  29 #include "xfs_quota.h"
  30 #include "xfs_mount.h"
  31 #include "xfs_bmap_btree.h"
  32 #include "xfs_alloc_btree.h"
  33 #include "xfs_ialloc_btree.h"
  34 #include "xfs_dir2_sf.h"
  35 #include "xfs_attr_sf.h"
  36 #include "xfs_dinode.h"
  37 #include "xfs_inode.h"
  38 #include "xfs_ialloc.h"
  39 #include "xfs_btree.h"
  40 #include "xfs_bmap.h"
  41 #include "xfs_rtalloc.h"
  42 #include "xfs_error.h"
  43 #include "xfs_itable.h"
  44 #include "xfs_rw.h"
  45 #include "xfs_acl.h"
  46 #include "xfs_attr.h"
  47 #include "xfs_buf_item.h"
  48 #include "xfs_trans_space.h"
  49 #include "xfs_utils.h"
  50 #include "xfs_iomap.h"
  51
  52 #if defined(XFS_RW_TRACE)
  53 void
  54 xfs_iomap_enter_trace(
  55         int             tag,
  56         xfs_iocore_t    *io,
  57         xfs_off_t       offset,
  58         ssize_t         count)
  59 {
  60         xfs_inode_t     *ip = XFS_IO_INODE(io);
  61
  62         if (!ip->i_rwtrace)
  63                 return;
  64
  65         ktrace_enter(ip->i_rwtrace,
  66                 (void *)((unsigned long)tag),
  67                 (void *)ip,
  68                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
  69                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
  70                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
  71                 (void *)((unsigned long)(offset & 0xffffffff)),
  72                 (void *)((unsigned long)count),
  73                 (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
  74                 (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
  75                 (void *)((unsigned long)current_pid()),
  76                 (void *)NULL,
  77                 (void *)NULL,
  78                 (void *)NULL,
  79                 (void *)NULL,
  80                 (void *)NULL,
  81                 (void *)NULL);
  82 }
  83
  84 void
  85 xfs_iomap_map_trace(
  86         int             tag,
  87         xfs_iocore_t    *io,
  88         xfs_off_t       offset,
  89         ssize_t         count,
  90         xfs_iomap_t     *iomapp,
  91         xfs_bmbt_irec_t *imapp,
  92         int             flags)
  93 {
  94         xfs_inode_t     *ip = XFS_IO_INODE(io);
  95
  96         if (!ip->i_rwtrace)
  97                 return;
  98
  99         ktrace_enter(ip->i_rwtrace,
 100                 (void *)((unsigned long)tag),
 101                 (void *)ip,
 102                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
 103                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
 104                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
 105                 (void *)((unsigned long)(offset & 0xffffffff)),
 106                 (void *)((unsigned long)count),
 107                 (void *)((unsigned long)flags),
 108                 (void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)),
 109                 (void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)),
 110                 (void *)((unsigned long)(iomapp->iomap_delta)),
 111                 (void *)((unsigned long)(iomapp->iomap_bsize)),
 112                 (void *)((unsigned long)(iomapp->iomap_bn)),
 113                 (void *)(__psint_t)(imapp->br_startoff),
 114                 (void *)((unsigned long)(imapp->br_blockcount)),
 115                 (void *)(__psint_t)(imapp->br_startblock));
 116 }
 117 #else
 118 #define xfs_iomap_enter_trace(tag, io, offset, count)
 119 #define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags)
 120 #endif
 121
 122 #define XFS_WRITEIO_ALIGN(mp,off)       (((off) >> mp->m_writeio_log) \
 123                                                 << mp->m_writeio_log)
 124 #define XFS_STRAT_WRITE_IMAPS   2
 125 #define XFS_WRITE_IMAPS         XFS_BMAP_MAX_NMAP
 126
 127 STATIC int
 128 xfs_imap_to_bmap(
 129         xfs_iocore_t    *io,
 130         xfs_off_t       offset,
 131         xfs_bmbt_irec_t *imap,
 132         xfs_iomap_t     *iomapp,
 133         int             imaps,                  /* Number of imap entries */
 134         int             iomaps,                 /* Number of iomap entries */
 135         int             flags)
 136 {
 137         xfs_mount_t     *mp;
 138         xfs_fsize_t     nisize;
 139         int             pbm;
 140         xfs_fsblock_t   start_block;
 141
 142         mp = io->io_mount;
 143         nisize = XFS_SIZE(mp, io);
 144         if (io->io_new_size > nisize)
 145                 nisize = io->io_new_size;
 146
 147         for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
 148                 iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
 149                 iomapp->iomap_delta = offset - iomapp->iomap_offset;
 150                 iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
 151                 iomapp->iomap_flags = flags;
 152
 153                 if (io->io_flags & XFS_IOCORE_RT) {
 154                         iomapp->iomap_flags |= IOMAP_REALTIME;
 155                         iomapp->iomap_target = mp->m_rtdev_targp;
 156                 } else {
 157                         iomapp->iomap_target = mp->m_ddev_targp;
 158                 }
 159                 start_block = imap->br_startblock;
 160                 if (start_block == HOLESTARTBLOCK) {
 161                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
 162                         iomapp->iomap_flags |= IOMAP_HOLE;
 163                 } else if (start_block == DELAYSTARTBLOCK) {
 164                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
 165                         iomapp->iomap_flags |= IOMAP_DELAY;
 166                 } else {
 167                         iomapp->iomap_bn = XFS_FSB_TO_DB_IO(io, start_block);
 168                         if (ISUNWRITTEN(imap))
 169                                 iomapp->iomap_flags |= IOMAP_UNWRITTEN;
 170                 }
 171
 172                 if ((iomapp->iomap_offset + iomapp->iomap_bsize) >= nisize) {
 173                         iomapp->iomap_flags |= IOMAP_EOF;
 174                 }
 175
 176                 offset += iomapp->iomap_bsize - iomapp->iomap_delta;
 177         }
 178         return pbm;     /* Return the number filled */
 179 }
 180
 181 int
 182 xfs_iomap(
 183         xfs_iocore_t    *io,
 184         xfs_off_t       offset,
 185         ssize_t         count,
 186         int             flags,
 187         xfs_iomap_t     *iomapp,
 188         int             *niomaps)
 189 {
 190         xfs_mount_t     *mp = io->io_mount;
 191         xfs_fileoff_t   offset_fsb, end_fsb;
 192         int             error = 0;
 193         int             lockmode = 0;
 194         xfs_bmbt_irec_t imap;
 195         int             nimaps = 1;
 196         int             bmapi_flags = 0;
 197         int             iomap_flags = 0;
 198
 199         if (XFS_FORCED_SHUTDOWN(mp))
 200                 return XFS_ERROR(EIO);
 201
 202         switch (flags &
 203                 (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE |
 204                  BMAPI_UNWRITTEN | BMAPI_DEVICE)) {
 205         case BMAPI_READ:
 206                 xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, io, offset, count);
 207                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
 208                 bmapi_flags = XFS_BMAPI_ENTIRE;
 209                 break;
 210         case BMAPI_WRITE:
 211                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, io, offset, count);
 212                 lockmode = XFS_ILOCK_EXCL|XFS_EXTSIZE_WR;
 213                 if (flags & BMAPI_IGNSTATE)
 214                         bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE;
 215                 XFS_ILOCK(mp, io, lockmode);
 216                 break;
 217         case BMAPI_ALLOCATE:
 218                 xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, io, offset, count);
 219                 lockmode = XFS_ILOCK_SHARED|XFS_EXTSIZE_RD;
 220                 bmapi_flags = XFS_BMAPI_ENTIRE;
 221                 /* Attempt non-blocking lock */
 222                 if (flags & BMAPI_TRYLOCK) {
 223                         if (!XFS_ILOCK_NOWAIT(mp, io, lockmode))
 224                                 return XFS_ERROR(EAGAIN);
 225                 } else {
 226                         XFS_ILOCK(mp, io, lockmode);
 227                 }
 228                 break;
 229         case BMAPI_UNWRITTEN:
 230                 goto phase2;
 231         case BMAPI_DEVICE:
 232                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
 233                 iomapp->iomap_target = io->io_flags & XFS_IOCORE_RT ?
 234                         mp->m_rtdev_targp : mp->m_ddev_targp;
 235                 error = 0;
 236                 *niomaps = 1;
 237                 goto out;
 238         default:
 239                 BUG();
 240         }
 241
 242         ASSERT(offset <= mp->m_maxioffset);
 243         if ((xfs_fsize_t)offset + count > mp->m_maxioffset)
 244                 count = mp->m_maxioffset - offset;
 245         end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
 246         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 247
 248         error = XFS_BMAPI(mp, NULL, io, offset_fsb,
 249                         (xfs_filblks_t)(end_fsb - offset_fsb),
 250                         bmapi_flags,  NULL, 0, &imap,
 251                         &nimaps, NULL, NULL);
 252
 253         if (error)
 254                 goto out;
 255
 256 phase2:
 257         switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE|BMAPI_UNWRITTEN)) {
 258         case BMAPI_WRITE:
 259                 /* If we found an extent, return it */
 260                 if (nimaps &&
 261                     (imap.br_startblock != HOLESTARTBLOCK) &&
 262                     (imap.br_startblock != DELAYSTARTBLOCK)) {
 263                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
 264                                         offset, count, iomapp, &imap, flags);
 265                         break;
 266                 }
 267
 268                 if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
 269                         error = XFS_IOMAP_WRITE_DIRECT(mp, io, offset,
 270                                         count, flags, &imap, &nimaps, nimaps);
 271                 } else {
 272                         error = XFS_IOMAP_WRITE_DELAY(mp, io, offset, count,
 273                                         flags, &imap, &nimaps);
 274                 }
 275                 if (!error) {
 276                         xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, io,
 277                                         offset, count, iomapp, &imap, flags);
 278                 }
 279                 iomap_flags = IOMAP_NEW;
 280                 break;
 281         case BMAPI_ALLOCATE:
 282                 /* If we found an extent, return it */
 283                 XFS_IUNLOCK(mp, io, lockmode);
 284                 lockmode = 0;
 285
 286                 if (nimaps && !ISNULLSTARTBLOCK(imap.br_startblock)) {
 287                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
 288                                         offset, count, iomapp, &imap, flags);
 289                         break;
 290                 }
 291
 292                 error = XFS_IOMAP_WRITE_ALLOCATE(mp, io, offset, count,
 293                                                  &imap, &nimaps);
 294                 break;
 295         case BMAPI_UNWRITTEN:
 296                 lockmode = 0;
 297                 error = XFS_IOMAP_WRITE_UNWRITTEN(mp, io, offset, count);
 298                 nimaps = 0;
 299                 break;
 300         }
 301
 302         if (nimaps) {
 303                 *niomaps = xfs_imap_to_bmap(io, offset, &imap,
 304                                             iomapp, nimaps, *niomaps, iomap_flags);
 305         } else if (niomaps) {
 306                 *niomaps = 0;
 307         }
 308
 309 out:
 310         if (lockmode)
 311                 XFS_IUNLOCK(mp, io, lockmode);
 312         return XFS_ERROR(error);
 313 }
 314
 315 STATIC int
 316 xfs_iomap_eof_align_last_fsb(
 317         xfs_mount_t     *mp,
 318         xfs_iocore_t    *io,
 319         xfs_fsize_t     isize,
 320         xfs_extlen_t    extsize,
 321         xfs_fileoff_t   *last_fsb)
 322 {
 323         xfs_fileoff_t   new_last_fsb = 0;
 324         xfs_extlen_t    align;
 325         int             eof, error;
 326
 327         if (io->io_flags & XFS_IOCORE_RT)
 328                 ;
 329         /*
 330          * If mounted with the "-o swalloc" option, roundup the allocation
 331          * request to a stripe width boundary if the file size is >=
 332          * stripe width and we are allocating past the allocation eof.
 333          */
 334         else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) &&
 335                 (isize >= XFS_FSB_TO_B(mp, mp->m_swidth)))
 336                 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth);
 337         /*
 338          * Roundup the allocation request to a stripe unit (m_dalign) boundary
 339          * if the file size is >= stripe unit size, and we are allocating past
 340          * the allocation eof.
 341          */
 342         else if (mp->m_dalign && (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)))
 343                 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign);
 344
 345         /*
 346          * Always round up the allocation request to an extent boundary
 347          * (when file on a real-time subvolume or has di_extsize hint).
 348          */
 349         if (extsize) {
 350                 if (new_last_fsb)
 351                         align = roundup_64(new_last_fsb, extsize);
 352                 else
 353                         align = extsize;
 354                 new_last_fsb = roundup_64(*last_fsb, align);
 355         }
 356
 357         if (new_last_fsb) {
 358                 error = XFS_BMAP_EOF(mp, io, new_last_fsb, XFS_DATA_FORK, &eof);
 359                 if (error)
 360                         return error;
 361                 if (eof)
 362                         *last_fsb = new_last_fsb;
 363         }
 364         return 0;
 365 }
 366
 367 STATIC int
 368 xfs_flush_space(
 369         xfs_inode_t     *ip,
 370         int             *fsynced,
 371         int             *ioflags)
 372 {
 373         switch (*fsynced) {
 374         case 0:
 375                 if (ip->i_delayed_blks) {
 376                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 377                         xfs_flush_inode(ip);
 378                         xfs_ilock(ip, XFS_ILOCK_EXCL);
 379                         *fsynced = 1;
 380                 } else {
 381                         *ioflags |= BMAPI_SYNC;
 382                         *fsynced = 2;
 383                 }
 384                 return 0;
 385         case 1:
 386                 *fsynced = 2;
 387                 *ioflags |= BMAPI_SYNC;
 388                 return 0;
 389         case 2:
 390                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 391                 xfs_flush_device(ip);
 392                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 393                 *fsynced = 3;
 394                 return 0;
 395         }
 396         return 1;
 397 }
 398
 399 STATIC int
 400 xfs_cmn_err_fsblock_zero(
 401         xfs_inode_t     *ip,
 402         xfs_bmbt_irec_t *imap)
 403 {
 404         xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount,
 405                         "Access to block zero in inode %llu "
 406                         "start_block: %llx start_off: %llx "
 407                         "blkcnt: %llx extent-state: %x\n",
 408                 (unsigned long long)ip->i_ino,
 409                 (unsigned long long)imap->br_startblock,
 410                 (unsigned long long)imap->br_startoff,
 411                 (unsigned long long)imap->br_blockcount,
 412                 imap->br_state);
 413         return EFSCORRUPTED;
 414 }
 415
 416 int
 417 xfs_iomap_write_direct(
 418         xfs_inode_t     *ip,
 419         xfs_off_t       offset,
 420         size_t          count,
 421         int             flags,
 422         xfs_bmbt_irec_t *ret_imap,
 423         int             *nmaps,
 424         int             found)
 425 {
 426         xfs_mount_t     *mp = ip->i_mount;
 427         xfs_iocore_t    *io = &ip->i_iocore;
 428         xfs_fileoff_t   offset_fsb;
 429         xfs_fileoff_t   last_fsb;
 430         xfs_filblks_t   count_fsb, resaligned;
 431         xfs_fsblock_t   firstfsb;
 432         xfs_extlen_t    extsz, temp;
 433         xfs_fsize_t     isize;
 434         int             nimaps;
 435         int             bmapi_flag;
 436         int             quota_flag;
 437         int             rt;
 438         xfs_trans_t     *tp;
 439         xfs_bmbt_irec_t imap;
 440         xfs_bmap_free_t free_list;
 441         uint            qblocks, resblks, resrtextents;
 442         int             committed;
 443         int             error;
 444
 445         /*
 446          * Make sure that the dquots are there. This doesn't hold
 447          * the ilock across a disk read.
 448          */
 449         error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
 450         if (error)
 451                 return XFS_ERROR(error);
 452
 453         rt = XFS_IS_REALTIME_INODE(ip);
 454         if (unlikely(rt)) {
 455                 if (!(extsz = ip->i_d.di_extsize))
 456                         extsz = mp->m_sb.sb_rextsize;
 457         } else {
 458                 extsz = ip->i_d.di_extsize;
 459         }
 460
 461         isize = ip->i_d.di_size;
 462         if (io->io_new_size > isize)
 463                 isize = io->io_new_size;
 464
 465         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 466         last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
 467         if ((offset + count) > isize) {
 468                 error = xfs_iomap_eof_align_last_fsb(mp, io, isize, extsz,
 469                                                         &last_fsb);
 470                 if (error)
 471                         goto error_out;
 472         } else {
 473                 if (found && (ret_imap->br_startblock == HOLESTARTBLOCK))
 474                         last_fsb = MIN(last_fsb, (xfs_fileoff_t)
 475                                         ret_imap->br_blockcount +
 476                                         ret_imap->br_startoff);
 477         }
 478         count_fsb = last_fsb - offset_fsb;
 479         ASSERT(count_fsb > 0);
 480
 481         resaligned = count_fsb;
 482         if (unlikely(extsz)) {
 483                 if ((temp = do_mod(offset_fsb, extsz)))
 484                         resaligned += temp;
 485                 if ((temp = do_mod(resaligned, extsz)))
 486                         resaligned += extsz - temp;
 487         }
 488
 489         if (unlikely(rt)) {
 490                 resrtextents = qblocks = resaligned;
 491                 resrtextents /= mp->m_sb.sb_rextsize;
 492                 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
 493                 quota_flag = XFS_QMOPT_RES_RTBLKS;
 494         } else {
 495                 resrtextents = 0;
 496                 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
 497                 quota_flag = XFS_QMOPT_RES_REGBLKS;
 498         }
 499
 500         /*
 501          * Allocate and setup the transaction
 502          */
 503         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 504         tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
 505         error = xfs_trans_reserve(tp, resblks,
 506                         XFS_WRITE_LOG_RES(mp), resrtextents,
 507                         XFS_TRANS_PERM_LOG_RES,
 508                         XFS_WRITE_LOG_COUNT);
 509         /*
 510          * Check for running out of space, note: need lock to return
 511          */
 512         if (error)
 513                 xfs_trans_cancel(tp, 0);
 514         xfs_ilock(ip, XFS_ILOCK_EXCL);
 515         if (error)
 516                 goto error_out;
 517
 518         error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip,
 519                                               qblocks, 0, quota_flag);
 520         if (error)
 521                 goto error1;
 522
 523         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 524         xfs_trans_ihold(tp, ip);
 525
 526         bmapi_flag = XFS_BMAPI_WRITE;
 527         if ((flags & BMAPI_DIRECT) && (offset < ip->i_d.di_size || extsz))
 528                 bmapi_flag |= XFS_BMAPI_PREALLOC;
 529
 530         /*
 531          * Issue the xfs_bmapi() call to allocate the blocks
 532          */
 533         XFS_BMAP_INIT(&free_list, &firstfsb);
 534         nimaps = 1;
 535         error = XFS_BMAPI(mp, tp, io, offset_fsb, count_fsb, bmapi_flag,
 536                 &firstfsb, 0, &imap, &nimaps, &free_list, NULL);
 537         if (error)
 538                 goto error0;
 539
 540         /*
 541          * Complete the transaction
 542          */
 543         error = xfs_bmap_finish(&tp, &free_list, &committed);
 544         if (error)
 545                 goto error0;
 546         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
 547         if (error)
 548                 goto error_out;
 549
 550         /*
 551          * Copy any maps to caller's array and return any error.
 552          */
 553         if (nimaps == 0) {
 554                 error = ENOSPC;
 555                 goto error_out;
 556         }
 557
 558         if (unlikely(!imap.br_startblock && !(io->io_flags & XFS_IOCORE_RT))) {
 559                 error = xfs_cmn_err_fsblock_zero(ip, &imap);
 560                 goto error_out;
 561         }
 562
 563         *ret_imap = imap;
 564         *nmaps = 1;
 565         return 0;
 566
 567 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
 568         xfs_bmap_cancel(&free_list);
 569         XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
 570
 571 error1: /* Just cancel transaction */
 572         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
 573         *nmaps = 0;     /* nothing set-up here */
 574
 575 error_out:
 576         return XFS_ERROR(error);
 577 }
 578
 579 /*
 580  * If the caller is doing a write at the end of the file,
 581  * then extend the allocation out to the file system's write
 582  * iosize.  We clean up any extra space left over when the
 583  * file is closed in xfs_inactive().
 584  *
 585  * For sync writes, we are flushing delayed allocate space to
 586  * try to make additional space available for allocation near
 587  * the filesystem full boundary - preallocation hurts in that
 588  * situation, of course.
 589  */
 590 STATIC int
 591 xfs_iomap_eof_want_preallocate(
 592         xfs_mount_t     *mp,
 593         xfs_iocore_t    *io,
 594         xfs_fsize_t     isize,
 595         xfs_off_t       offset,
 596         size_t          count,
 597         int             ioflag,
 598         xfs_bmbt_irec_t *imap,
 599         int             nimaps,
 600         int             *prealloc)
 601 {
 602         xfs_fileoff_t   start_fsb;
 603         xfs_filblks_t   count_fsb;
 604         xfs_fsblock_t   firstblock;
 605         int             n, error, imaps;
 606
 607         *prealloc = 0;
 608         if ((ioflag & BMAPI_SYNC) || (offset + count) <= isize)
 609                 return 0;
 610
 611         /*
 612          * If there are any real blocks past eof, then don't
 613          * do any speculative allocation.
 614          */
 615         start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
 616         count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
 617         while (count_fsb > 0) {
 618                 imaps = nimaps;
 619                 firstblock = NULLFSBLOCK;
 620                 error = XFS_BMAPI(mp, NULL, io, start_fsb, count_fsb, 0,
 621                                   &firstblock, 0, imap, &imaps, NULL, NULL);
 622                 if (error)
 623                         return error;
 624                 for (n = 0; n < imaps; n++) {
 625                         if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
 626                             (imap[n].br_startblock != DELAYSTARTBLOCK))
 627                                 return 0;
 628                         start_fsb += imap[n].br_blockcount;
 629                         count_fsb -= imap[n].br_blockcount;
 630                 }
 631         }
 632         *prealloc = 1;
 633         return 0;
 634 }
 635
 636 int
 637 xfs_iomap_write_delay(
 638         xfs_inode_t     *ip,
 639         xfs_off_t       offset,
 640         size_t          count,
 641         int             ioflag,
 642         xfs_bmbt_irec_t *ret_imap,
 643         int             *nmaps)
 644 {
 645         xfs_mount_t     *mp = ip->i_mount;
 646         xfs_iocore_t    *io = &ip->i_iocore;
 647         xfs_fileoff_t   offset_fsb;
 648         xfs_fileoff_t   last_fsb;
 649         xfs_off_t       aligned_offset;
 650         xfs_fileoff_t   ioalign;
 651         xfs_fsblock_t   firstblock;
 652         xfs_extlen_t    extsz;
 653         xfs_fsize_t     isize;
 654         int             nimaps;
 655         xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
 656         int             prealloc, fsynced = 0;
 657         int             error;
 658
 659         ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
 660
 661         /*
 662          * Make sure that the dquots are there. This doesn't hold
 663          * the ilock across a disk read.
 664          */
 665         error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
 666         if (error)
 667                 return XFS_ERROR(error);
 668
 669         if (XFS_IS_REALTIME_INODE(ip)) {
 670                 if (!(extsz = ip->i_d.di_extsize))
 671                         extsz = mp->m_sb.sb_rextsize;
 672         } else {
 673                 extsz = ip->i_d.di_extsize;
 674         }
 675
 676         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 677
 678 retry:
 679         isize = ip->i_d.di_size;
 680         if (io->io_new_size > isize)
 681                 isize = io->io_new_size;
 682
 683         error = xfs_iomap_eof_want_preallocate(mp, io, isize, offset, count,
 684                                 ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
 685         if (error)
 686                 return error;
 687
 688         if (prealloc) {
 689                 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
 690                 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
 691                 last_fsb = ioalign + mp->m_writeio_blocks;
 692         } else {
 693                 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
 694         }
 695
 696         if (prealloc || extsz) {
 697                 error = xfs_iomap_eof_align_last_fsb(mp, io, isize, extsz,
 698                                                         &last_fsb);
 699                 if (error)
 700                         return error;
 701         }
 702
 703         nimaps = XFS_WRITE_IMAPS;
 704         firstblock = NULLFSBLOCK;
 705         error = XFS_BMAPI(mp, NULL, io, offset_fsb,
 706                           (xfs_filblks_t)(last_fsb - offset_fsb),
 707                           XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
 708                           XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
 709                           &nimaps, NULL, NULL);
 710         if (error && (error != ENOSPC))
 711                 return XFS_ERROR(error);
 712
 713         /*
 714          * If bmapi returned us nothing, and if we didn't get back EDQUOT,
 715          * then we must have run out of space - flush delalloc, and retry..
 716          */
 717         if (nimaps == 0) {
 718                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
 719                                         io, offset, count);
 720                 if (xfs_flush_space(ip, &fsynced, &ioflag))
 721                         return XFS_ERROR(ENOSPC);
 722
 723                 error = 0;
 724                 goto retry;
 725         }
 726
 727         if (unlikely(!imap[0].br_startblock && !(io->io_flags & XFS_IOCORE_RT)))
 728                 return xfs_cmn_err_fsblock_zero(ip, &imap[0]);
 729
 730         *ret_imap = imap[0];
 731         *nmaps = 1;
 732
 733         return 0;
 734 }
 735
 736 /*
 737  * Pass in a delayed allocate extent, convert it to real extents;
 738  * return to the caller the extent we create which maps on top of
 739  * the originating callers request.
 740  *
 741  * Called without a lock on the inode.
 742  */
 743 int
 744 xfs_iomap_write_allocate(
 745         xfs_inode_t     *ip,
 746         xfs_off_t       offset,
 747         size_t          count,
 748         xfs_bmbt_irec_t *map,
 749         int             *retmap)
 750 {
 751         xfs_mount_t     *mp = ip->i_mount;
 752         xfs_iocore_t    *io = &ip->i_iocore;
 753         xfs_fileoff_t   offset_fsb, last_block;
 754         xfs_fileoff_t   end_fsb, map_start_fsb;
 755         xfs_fsblock_t   first_block;
 756         xfs_bmap_free_t free_list;
 757         xfs_filblks_t   count_fsb;
 758         xfs_bmbt_irec_t imap[XFS_STRAT_WRITE_IMAPS];
 759         xfs_trans_t     *tp;
 760         int             i, nimaps, committed;
 761         int             error = 0;
 762         int             nres;
 763
 764         *retmap = 0;
 765
 766         /*
 767          * Make sure that the dquots are there.
 768          */
 769         if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
 770                 return XFS_ERROR(error);
 771
 772         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 773         count_fsb = map->br_blockcount;
 774         map_start_fsb = map->br_startoff;
 775
 776         XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
 777
 778         while (count_fsb != 0) {
 779                 /*
 780                  * Set up a transaction with which to allocate the
 781                  * backing store for the file.  Do allocations in a
 782                  * loop until we get some space in the range we are
 783                  * interested in.  The other space that might be allocated
 784                  * is in the delayed allocation extent on which we sit
 785                  * but before our buffer starts.
 786                  */
 787
 788                 nimaps = 0;
 789                 while (nimaps == 0) {
 790                         tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
 791                         nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
 792                         error = xfs_trans_reserve(tp, nres,
 793                                         XFS_WRITE_LOG_RES(mp),
 794                                         0, XFS_TRANS_PERM_LOG_RES,
 795                                         XFS_WRITE_LOG_COUNT);
 796                         if (error == ENOSPC) {
 797                                 error = xfs_trans_reserve(tp, 0,
 798                                                 XFS_WRITE_LOG_RES(mp),
 799                                                 0,
 800                                                 XFS_TRANS_PERM_LOG_RES,
 801                                                 XFS_WRITE_LOG_COUNT);
 802                         }
 803                         if (error) {
 804                                 xfs_trans_cancel(tp, 0);
 805                                 return XFS_ERROR(error);
 806                         }
 807                         xfs_ilock(ip, XFS_ILOCK_EXCL);
 808                         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 809                         xfs_trans_ihold(tp, ip);
 810
 811                         XFS_BMAP_INIT(&free_list, &first_block);
 812
 813                         nimaps = XFS_STRAT_WRITE_IMAPS;
 814                         /*
 815                          * Ensure we don't go beyond eof - it is possible
 816                          * the extents changed since we did the read call,
 817                          * we dropped the ilock in the interim.
 818                          */
 819
 820                         end_fsb = XFS_B_TO_FSB(mp, ip->i_d.di_size);
 821                         xfs_bmap_last_offset(NULL, ip, &last_block,
 822                                 XFS_DATA_FORK);
 823                         last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
 824                         if ((map_start_fsb + count_fsb) > last_block) {
 825                                 count_fsb = last_block - map_start_fsb;
 826                                 if (count_fsb == 0) {
 827                                         error = EAGAIN;
 828                                         goto trans_cancel;
 829                                 }
 830                         }
 831
 832                         /* Go get the actual blocks */
 833                         error = XFS_BMAPI(mp, tp, io, map_start_fsb, count_fsb,
 834                                         XFS_BMAPI_WRITE, &first_block, 1,
 835                                         imap, &nimaps, &free_list, NULL);
 836                         if (error)
 837                                 goto trans_cancel;
 838
 839                         error = xfs_bmap_finish(&tp, &free_list, &committed);
 840                         if (error)
 841                                 goto trans_cancel;
 842
 843                         error = xfs_trans_commit(tp,
 844                                         XFS_TRANS_RELEASE_LOG_RES, NULL);
 845                         if (error)
 846                                 goto error0;
 847
 848                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 849                 }
 850
 851                 /*
 852                  * See if we were able to allocate an extent that
 853                  * covers at least part of the callers request
 854                  */
 855                 for (i = 0; i < nimaps; i++) {
 856                         if (unlikely(!imap[i].br_startblock &&
 857                                      !(io->io_flags & XFS_IOCORE_RT)))
 858                                 return xfs_cmn_err_fsblock_zero(ip, &imap[i]);
 859                         if ((offset_fsb >= imap[i].br_startoff) &&
 860                             (offset_fsb < (imap[i].br_startoff +
 861                                            imap[i].br_blockcount))) {
 862                                 *map = imap[i];
 863                                 *retmap = 1;
 864                                 XFS_STATS_INC(xs_xstrat_quick);
 865                                 return 0;
 866                         }
 867                         count_fsb -= imap[i].br_blockcount;
 868                 }
 869
 870                 /* So far we have not mapped the requested part of the
 871                  * file, just surrounding data, try again.
 872                  */
 873                 nimaps--;
 874                 map_start_fsb = imap[nimaps].br_startoff +
 875                                 imap[nimaps].br_blockcount;
 876         }
 877
 878 trans_cancel:
 879         xfs_bmap_cancel(&free_list);
 880         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
 881 error0:
 882         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 883         return XFS_ERROR(error);
 884 }
 885
 886 int
 887 xfs_iomap_write_unwritten(
 888         xfs_inode_t     *ip,
 889         xfs_off_t       offset,
 890         size_t          count)
 891 {
 892         xfs_mount_t     *mp = ip->i_mount;
 893         xfs_iocore_t    *io = &ip->i_iocore;
 894         xfs_fileoff_t   offset_fsb;
 895         xfs_filblks_t   count_fsb;
 896         xfs_filblks_t   numblks_fsb;
 897         xfs_fsblock_t   firstfsb;
 898         int             nimaps;
 899         xfs_trans_t     *tp;
 900         xfs_bmbt_irec_t imap;
 901         xfs_bmap_free_t free_list;
 902         uint            resblks;
 903         int             committed;
 904         int             error;
 905
 906         xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN,
 907                                 &ip->i_iocore, offset, count);
 908
 909         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 910         count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
 911         count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
 912
 913         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
 914
 915         do {
 916                 /*
 917                  * set up a transaction to convert the range of extents
 918                  * from unwritten to real. Do allocations in a loop until
 919                  * we have covered the range passed in.
 920                  */
 921
 922                 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
 923                 error = xfs_trans_reserve(tp, resblks,
 924                                 XFS_WRITE_LOG_RES(mp), 0,
 925                                 XFS_TRANS_PERM_LOG_RES,
 926                                 XFS_WRITE_LOG_COUNT);
 927                 if (error) {
 928                         xfs_trans_cancel(tp, 0);
 929                         return XFS_ERROR(error);
 930                 }
 931
 932                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 933                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 934                 xfs_trans_ihold(tp, ip);
 935
 936                 /*
 937                  * Modify the unwritten extent state of the buffer.
 938                  */
 939                 XFS_BMAP_INIT(&free_list, &firstfsb);
 940                 nimaps = 1;
 941                 error = XFS_BMAPI(mp, tp, io, offset_fsb, count_fsb,
 942                                   XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb,
 943                                   1, &imap, &nimaps, &free_list, NULL);
 944                 if (error)
 945                         goto error_on_bmapi_transaction;
 946
 947                 error = xfs_bmap_finish(&(tp), &(free_list), &committed);
 948                 if (error)
 949                         goto error_on_bmapi_transaction;
 950
 951                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
 952                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 953                 if (error)
 954                         return XFS_ERROR(error);
 955
 956                 if (unlikely(!imap.br_startblock &&
 957                              !(io->io_flags & XFS_IOCORE_RT)))
 958                         return xfs_cmn_err_fsblock_zero(ip, &imap);
 959
 960                 if ((numblks_fsb = imap.br_blockcount) == 0) {
 961                         /*
 962                          * The numblks_fsb value should always get
 963                          * smaller, otherwise the loop is stuck.
 964                          */
 965                         ASSERT(imap.br_blockcount);
 966                         break;
 967                 }
 968                 offset_fsb += numblks_fsb;
 969                 count_fsb -= numblks_fsb;
 970         } while (count_fsb > 0);
 971
 972         return 0;
 973
 974 error_on_bmapi_transaction:
 975         xfs_bmap_cancel(&free_list);
 976         xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
 977         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 978         return XFS_ERROR(error);
 979 }