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_cap.h"
  47 #include "xfs_mac.h"
  48 #include "xfs_attr.h"
  49 #include "xfs_buf_item.h"
  50 #include "xfs_trans_space.h"
  51 #include "xfs_utils.h"
  52 #include "xfs_iomap.h"
  53
  54 #if defined(XFS_RW_TRACE)
  55 void
  56 xfs_iomap_enter_trace(
  57         int             tag,
  58         xfs_iocore_t    *io,
  59         xfs_off_t       offset,
  60         ssize_t         count)
  61 {
  62         xfs_inode_t     *ip = XFS_IO_INODE(io);
  63
  64         if (!ip->i_rwtrace)
  65                 return;
  66
  67         ktrace_enter(ip->i_rwtrace,
  68                 (void *)((unsigned long)tag),
  69                 (void *)ip,
  70                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
  71                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
  72                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
  73                 (void *)((unsigned long)(offset & 0xffffffff)),
  74                 (void *)((unsigned long)count),
  75                 (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
  76                 (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
  77                 (void *)((unsigned long)current_pid()),
  78                 (void *)NULL,
  79                 (void *)NULL,
  80                 (void *)NULL,
  81                 (void *)NULL,
  82                 (void *)NULL,
  83                 (void *)NULL);
  84 }
  85
  86 void
  87 xfs_iomap_map_trace(
  88         int             tag,
  89         xfs_iocore_t    *io,
  90         xfs_off_t       offset,
  91         ssize_t         count,
  92         xfs_iomap_t     *iomapp,
  93         xfs_bmbt_irec_t *imapp,
  94         int             flags)
  95 {
  96         xfs_inode_t     *ip = XFS_IO_INODE(io);
  97
  98         if (!ip->i_rwtrace)
  99                 return;
 100
 101         ktrace_enter(ip->i_rwtrace,
 102                 (void *)((unsigned long)tag),
 103                 (void *)ip,
 104                 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
 105                 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
 106                 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
 107                 (void *)((unsigned long)(offset & 0xffffffff)),
 108                 (void *)((unsigned long)count),
 109                 (void *)((unsigned long)flags),
 110                 (void *)((unsigned long)((iomapp->iomap_offset >> 32) & 0xffffffff)),
 111                 (void *)((unsigned long)(iomapp->iomap_offset & 0xffffffff)),
 112                 (void *)((unsigned long)(iomapp->iomap_delta)),
 113                 (void *)((unsigned long)(iomapp->iomap_bsize)),
 114                 (void *)((unsigned long)(iomapp->iomap_bn)),
 115                 (void *)(__psint_t)(imapp->br_startoff),
 116                 (void *)((unsigned long)(imapp->br_blockcount)),
 117                 (void *)(__psint_t)(imapp->br_startblock));
 118 }
 119 #else
 120 #define xfs_iomap_enter_trace(tag, io, offset, count)
 121 #define xfs_iomap_map_trace(tag, io, offset, count, iomapp, imapp, flags)
 122 #endif
 123
 124 #define XFS_WRITEIO_ALIGN(mp,off)       (((off) >> mp->m_writeio_log) \
 125                                                 << mp->m_writeio_log)
 126 #define XFS_STRAT_WRITE_IMAPS   2
 127 #define XFS_WRITE_IMAPS         XFS_BMAP_MAX_NMAP
 128
 129 STATIC int
 130 xfs_imap_to_bmap(
 131         xfs_iocore_t    *io,
 132         xfs_off_t       offset,
 133         xfs_bmbt_irec_t *imap,
 134         xfs_iomap_t     *iomapp,
 135         int             imaps,                  /* Number of imap entries */
 136         int             iomaps,                 /* Number of iomap entries */
 137         int             flags)
 138 {
 139         xfs_mount_t     *mp;
 140         xfs_fsize_t     nisize;
 141         int             pbm;
 142         xfs_fsblock_t   start_block;
 143
 144         mp = io->io_mount;
 145         nisize = XFS_SIZE(mp, io);
 146         if (io->io_new_size > nisize)
 147                 nisize = io->io_new_size;
 148
 149         for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
 150                 iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
 151                 iomapp->iomap_delta = offset - iomapp->iomap_offset;
 152                 iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
 153                 iomapp->iomap_flags = flags;
 154
 155                 if (io->io_flags & XFS_IOCORE_RT) {
 156                         iomapp->iomap_flags |= IOMAP_REALTIME;
 157                         iomapp->iomap_target = mp->m_rtdev_targp;
 158                 } else {
 159                         iomapp->iomap_target = mp->m_ddev_targp;
 160                 }
 161                 start_block = imap->br_startblock;
 162                 if (start_block == HOLESTARTBLOCK) {
 163                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
 164                         iomapp->iomap_flags |= IOMAP_HOLE;
 165                 } else if (start_block == DELAYSTARTBLOCK) {
 166                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
 167                         iomapp->iomap_flags |= IOMAP_DELAY;
 168                 } else {
 169                         iomapp->iomap_bn = XFS_FSB_TO_DB_IO(io, start_block);
 170                         if (ISUNWRITTEN(imap))
 171                                 iomapp->iomap_flags |= IOMAP_UNWRITTEN;
 172                 }
 173
 174                 if ((iomapp->iomap_offset + iomapp->iomap_bsize) >= nisize) {
 175                         iomapp->iomap_flags |= IOMAP_EOF;
 176                 }
 177
 178                 offset += iomapp->iomap_bsize - iomapp->iomap_delta;
 179         }
 180         return pbm;     /* Return the number filled */
 181 }
 182
 183 int
 184 xfs_iomap(
 185         xfs_iocore_t    *io,
 186         xfs_off_t       offset,
 187         ssize_t         count,
 188         int             flags,
 189         xfs_iomap_t     *iomapp,
 190         int             *niomaps)
 191 {
 192         xfs_mount_t     *mp = io->io_mount;
 193         xfs_fileoff_t   offset_fsb, end_fsb;
 194         int             error = 0;
 195         int             lockmode = 0;
 196         xfs_bmbt_irec_t imap;
 197         int             nimaps = 1;
 198         int             bmapi_flags = 0;
 199         int             iomap_flags = 0;
 200
 201         if (XFS_FORCED_SHUTDOWN(mp))
 202                 return XFS_ERROR(EIO);
 203
 204         switch (flags &
 205                 (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE |
 206                  BMAPI_UNWRITTEN | BMAPI_DEVICE)) {
 207         case BMAPI_READ:
 208                 xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, io, offset, count);
 209                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
 210                 bmapi_flags = XFS_BMAPI_ENTIRE;
 211                 break;
 212         case BMAPI_WRITE:
 213                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, io, offset, count);
 214                 lockmode = XFS_ILOCK_EXCL|XFS_EXTSIZE_WR;
 215                 if (flags & BMAPI_IGNSTATE)
 216                         bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE;
 217                 XFS_ILOCK(mp, io, lockmode);
 218                 break;
 219         case BMAPI_ALLOCATE:
 220                 xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, io, offset, count);
 221                 lockmode = XFS_ILOCK_SHARED|XFS_EXTSIZE_RD;
 222                 bmapi_flags = XFS_BMAPI_ENTIRE;
 223                 /* Attempt non-blocking lock */
 224                 if (flags & BMAPI_TRYLOCK) {
 225                         if (!XFS_ILOCK_NOWAIT(mp, io, lockmode))
 226                                 return XFS_ERROR(EAGAIN);
 227                 } else {
 228                         XFS_ILOCK(mp, io, lockmode);
 229                 }
 230                 break;
 231         case BMAPI_UNWRITTEN:
 232                 goto phase2;
 233         case BMAPI_DEVICE:
 234                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
 235                 iomapp->iomap_target = io->io_flags & XFS_IOCORE_RT ?
 236                         mp->m_rtdev_targp : mp->m_ddev_targp;
 237                 error = 0;
 238                 *niomaps = 1;
 239                 goto out;
 240         default:
 241                 BUG();
 242         }
 243
 244         ASSERT(offset <= mp->m_maxioffset);
 245         if ((xfs_fsize_t)offset + count > mp->m_maxioffset)
 246                 count = mp->m_maxioffset - offset;
 247         end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
 248         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 249
 250         error = XFS_BMAPI(mp, NULL, io, offset_fsb,
 251                         (xfs_filblks_t)(end_fsb - offset_fsb),
 252                         bmapi_flags,  NULL, 0, &imap,
 253                         &nimaps, NULL, NULL);
 254
 255         if (error)
 256                 goto out;
 257
 258 phase2:
 259         switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE|BMAPI_UNWRITTEN)) {
 260         case BMAPI_WRITE:
 261                 /* If we found an extent, return it */
 262                 if (nimaps &&
 263                     (imap.br_startblock != HOLESTARTBLOCK) &&
 264                     (imap.br_startblock != DELAYSTARTBLOCK)) {
 265                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
 266                                         offset, count, iomapp, &imap, flags);
 267                         break;
 268                 }
 269
 270                 if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
 271                         error = XFS_IOMAP_WRITE_DIRECT(mp, io, offset,
 272                                         count, flags, &imap, &nimaps, nimaps);
 273                 } else {
 274                         error = XFS_IOMAP_WRITE_DELAY(mp, io, offset, count,
 275                                         flags, &imap, &nimaps);
 276                 }
 277                 if (!error) {
 278                         xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, io,
 279                                         offset, count, iomapp, &imap, flags);
 280                 }
 281                 iomap_flags = IOMAP_NEW;
 282                 break;
 283         case BMAPI_ALLOCATE:
 284                 /* If we found an extent, return it */
 285                 XFS_IUNLOCK(mp, io, lockmode);
 286                 lockmode = 0;
 287
 288                 if (nimaps && !ISNULLSTARTBLOCK(imap.br_startblock)) {
 289                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
 290                                         offset, count, iomapp, &imap, flags);
 291                         break;
 292                 }
 293
 294                 error = XFS_IOMAP_WRITE_ALLOCATE(mp, io, offset, count,
 295                                                  &imap, &nimaps);
 296                 break;
 297         case BMAPI_UNWRITTEN:
 298                 lockmode = 0;
 299                 error = XFS_IOMAP_WRITE_UNWRITTEN(mp, io, offset, count);
 300                 nimaps = 0;
 301                 break;
 302         }
 303
 304         if (nimaps) {
 305                 *niomaps = xfs_imap_to_bmap(io, offset, &imap,
 306                                             iomapp, nimaps, *niomaps, iomap_flags);
 307         } else if (niomaps) {
 308                 *niomaps = 0;
 309         }
 310
 311 out:
 312         if (lockmode)
 313                 XFS_IUNLOCK(mp, io, lockmode);
 314         return XFS_ERROR(error);
 315 }
 316
 317 STATIC int
 318 xfs_iomap_eof_align_last_fsb(
 319         xfs_mount_t     *mp,
 320         xfs_iocore_t    *io,
 321         xfs_fsize_t     isize,
 322         xfs_extlen_t    extsize,
 323         xfs_fileoff_t   *last_fsb)
 324 {
 325         xfs_fileoff_t   new_last_fsb = 0;
 326         xfs_extlen_t    align;
 327         int             eof, error;
 328
 329         if (io->io_flags & XFS_IOCORE_RT)
 330                 ;
 331         /*
 332          * If mounted with the "-o swalloc" option, roundup the allocation
 333          * request to a stripe width boundary if the file size is >=
 334          * stripe width and we are allocating past the allocation eof.
 335          */
 336         else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) &&
 337                 (isize >= XFS_FSB_TO_B(mp, mp->m_swidth)))
 338                 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth);
 339         /*
 340          * Roundup the allocation request to a stripe unit (m_dalign) boundary
 341          * if the file size is >= stripe unit size, and we are allocating past
 342          * the allocation eof.
 343          */
 344         else if (mp->m_dalign && (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)))
 345                 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign);
 346
 347         /*
 348          * Always round up the allocation request to an extent boundary
 349          * (when file on a real-time subvolume or has di_extsize hint).
 350          */
 351         if (extsize) {
 352                 if (new_last_fsb)
 353                         align = roundup_64(new_last_fsb, extsize);
 354                 else
 355                         align = extsize;
 356                 new_last_fsb = roundup_64(*last_fsb, align);
 357         }
 358
 359         if (new_last_fsb) {
 360                 error = XFS_BMAP_EOF(mp, io, new_last_fsb, XFS_DATA_FORK, &eof);
 361                 if (error)
 362                         return error;
 363                 if (eof)
 364                         *last_fsb = new_last_fsb;
 365         }
 366         return 0;
 367 }
 368
 369 STATIC int
 370 xfs_flush_space(
 371         xfs_inode_t     *ip,
 372         int             *fsynced,
 373         int             *ioflags)
 374 {
 375         switch (*fsynced) {
 376         case 0:
 377                 if (ip->i_delayed_blks) {
 378                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 379                         xfs_flush_inode(ip);
 380                         xfs_ilock(ip, XFS_ILOCK_EXCL);
 381                         *fsynced = 1;
 382                 } else {
 383                         *ioflags |= BMAPI_SYNC;
 384                         *fsynced = 2;
 385                 }
 386                 return 0;
 387         case 1:
 388                 *fsynced = 2;
 389                 *ioflags |= BMAPI_SYNC;
 390                 return 0;
 391         case 2:
 392                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 393                 xfs_flush_device(ip);
 394                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 395                 *fsynced = 3;
 396                 return 0;
 397         }
 398         return 1;
 399 }
 400
 401 STATIC int
 402 xfs_cmn_err_fsblock_zero(
 403         xfs_inode_t     *ip,
 404         xfs_bmbt_irec_t *imap)
 405 {
 406         xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount,
 407                         "Access to block zero in inode %llu "
 408                         "start_block: %llx start_off: %llx "
 409                         "blkcnt: %llx extent-state: %x\n",
 410                 (unsigned long long)ip->i_ino,
 411                 (unsigned long long)imap->br_startblock,
 412                 (unsigned long long)imap->br_startoff,
 413                 (unsigned long long)imap->br_blockcount,
 414                 imap->br_state);
 415         return EFSCORRUPTED;
 416 }
 417
 418 int
 419 xfs_iomap_write_direct(
 420         xfs_inode_t     *ip,
 421         xfs_off_t       offset,
 422         size_t          count,
 423         int             flags,
 424         xfs_bmbt_irec_t *ret_imap,
 425         int             *nmaps,
 426         int             found)
 427 {
 428         xfs_mount_t     *mp = ip->i_mount;
 429         xfs_iocore_t    *io = &ip->i_iocore;
 430         xfs_fileoff_t   offset_fsb;
 431         xfs_fileoff_t   last_fsb;
 432         xfs_filblks_t   count_fsb, resaligned;
 433         xfs_fsblock_t   firstfsb;
 434         xfs_extlen_t    extsz, temp;
 435         xfs_fsize_t     isize;
 436         int             nimaps;
 437         int             bmapi_flag;
 438         int             quota_flag;
 439         int             rt;
 440         xfs_trans_t     *tp;
 441         xfs_bmbt_irec_t imap;
 442         xfs_bmap_free_t free_list;
 443         uint            qblocks, resblks, resrtextents;
 444         int             committed;
 445         int             error;
 446
 447         /*
 448          * Make sure that the dquots are there. This doesn't hold
 449          * the ilock across a disk read.
 450          */
 451         error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
 452         if (error)
 453                 return XFS_ERROR(error);
 454
 455         rt = XFS_IS_REALTIME_INODE(ip);
 456         if (unlikely(rt)) {
 457                 if (!(extsz = ip->i_d.di_extsize))
 458                         extsz = mp->m_sb.sb_rextsize;
 459         } else {
 460                 extsz = ip->i_d.di_extsize;
 461         }
 462
 463         isize = ip->i_d.di_size;
 464         if (io->io_new_size > isize)
 465                 isize = io->io_new_size;
 466
 467         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 468         last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
 469         if ((offset + count) > isize) {
 470                 error = xfs_iomap_eof_align_last_fsb(mp, io, isize, extsz,
 471                                                         &last_fsb);
 472                 if (error)
 473                         goto error_out;
 474         } else {
 475                 if (found && (ret_imap->br_startblock == HOLESTARTBLOCK))
 476                         last_fsb = MIN(last_fsb, (xfs_fileoff_t)
 477                                         ret_imap->br_blockcount +
 478                                         ret_imap->br_startoff);
 479         }
 480         count_fsb = last_fsb - offset_fsb;
 481         ASSERT(count_fsb > 0);
 482
 483         resaligned = count_fsb;
 484         if (unlikely(extsz)) {
 485                 if ((temp = do_mod(offset_fsb, extsz)))
 486                         resaligned += temp;
 487                 if ((temp = do_mod(resaligned, extsz)))
 488                         resaligned += extsz - temp;
 489         }
 490
 491         if (unlikely(rt)) {
 492                 resrtextents = qblocks = resaligned;
 493                 resrtextents /= mp->m_sb.sb_rextsize;
 494                 resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
 495                 quota_flag = XFS_QMOPT_RES_RTBLKS;
 496         } else {
 497                 resrtextents = 0;
 498                 resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
 499                 quota_flag = XFS_QMOPT_RES_REGBLKS;
 500         }
 501
 502         /*
 503          * Allocate and setup the transaction
 504          */
 505         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 506         tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
 507         error = xfs_trans_reserve(tp, resblks,
 508                         XFS_WRITE_LOG_RES(mp), resrtextents,
 509                         XFS_TRANS_PERM_LOG_RES,
 510                         XFS_WRITE_LOG_COUNT);
 511         /*
 512          * Check for running out of space, note: need lock to return
 513          */
 514         if (error)
 515                 xfs_trans_cancel(tp, 0);
 516         xfs_ilock(ip, XFS_ILOCK_EXCL);
 517         if (error)
 518                 goto error_out;
 519
 520         error = XFS_TRANS_RESERVE_QUOTA_NBLKS(mp, tp, ip,
 521                                               qblocks, 0, quota_flag);
 522         if (error)
 523                 goto error1;
 524
 525         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 526         xfs_trans_ihold(tp, ip);
 527
 528         bmapi_flag = XFS_BMAPI_WRITE;
 529         if ((flags & BMAPI_DIRECT) && (offset < ip->i_d.di_size || extsz))
 530                 bmapi_flag |= XFS_BMAPI_PREALLOC;
 531
 532         /*
 533          * Issue the xfs_bmapi() call to allocate the blocks
 534          */
 535         XFS_BMAP_INIT(&free_list, &firstfsb);
 536         nimaps = 1;
 537         error = XFS_BMAPI(mp, tp, io, offset_fsb, count_fsb, bmapi_flag,
 538                 &firstfsb, 0, &imap, &nimaps, &free_list, NULL);
 539         if (error)
 540                 goto error0;
 541
 542         /*
 543          * Complete the transaction
 544          */
 545         error = xfs_bmap_finish(&tp, &free_list, firstfsb, &committed);
 546         if (error)
 547                 goto error0;
 548         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
 549         if (error)
 550                 goto error_out;
 551
 552         /*
 553          * Copy any maps to caller's array and return any error.
 554          */
 555         if (nimaps == 0) {
 556                 error = ENOSPC;
 557                 goto error_out;
 558         }
 559
 560         if (unlikely(!imap.br_startblock && !(io->io_flags & XFS_IOCORE_RT))) {
 561                 error = xfs_cmn_err_fsblock_zero(ip, &imap);
 562                 goto error_out;
 563         }
 564
 565         *ret_imap = imap;
 566         *nmaps = 1;
 567         return 0;
 568
 569 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
 570         xfs_bmap_cancel(&free_list);
 571         XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
 572
 573 error1: /* Just cancel transaction */
 574         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
 575         *nmaps = 0;     /* nothing set-up here */
 576
 577 error_out:
 578         return XFS_ERROR(error);
 579 }
 580
 581 /*
 582  * If the caller is doing a write at the end of the file,
 583  * then extend the allocation out to the file system's write
 584  * iosize.  We clean up any extra space left over when the
 585  * file is closed in xfs_inactive().
 586  *
 587  * For sync writes, we are flushing delayed allocate space to
 588  * try to make additional space available for allocation near
 589  * the filesystem full boundary - preallocation hurts in that
 590  * situation, of course.
 591  */
 592 STATIC int
 593 xfs_iomap_eof_want_preallocate(
 594         xfs_mount_t     *mp,
 595         xfs_iocore_t    *io,
 596         xfs_fsize_t     isize,
 597         xfs_off_t       offset,
 598         size_t          count,
 599         int             ioflag,
 600         xfs_bmbt_irec_t *imap,
 601         int             nimaps,
 602         int             *prealloc)
 603 {
 604         xfs_fileoff_t   start_fsb;
 605         xfs_filblks_t   count_fsb;
 606         xfs_fsblock_t   firstblock;
 607         int             n, error, imaps;
 608
 609         *prealloc = 0;
 610         if ((ioflag & BMAPI_SYNC) || (offset + count) <= isize)
 611                 return 0;
 612
 613         /*
 614          * If there are any real blocks past eof, then don't
 615          * do any speculative allocation.
 616          */
 617         start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
 618         count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
 619         while (count_fsb > 0) {
 620                 imaps = nimaps;
 621                 firstblock = NULLFSBLOCK;
 622                 error = XFS_BMAPI(mp, NULL, io, start_fsb, count_fsb, 0,
 623                                   &firstblock, 0, imap, &imaps, NULL, NULL);
 624                 if (error)
 625                         return error;
 626                 for (n = 0; n < imaps; n++) {
 627                         if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
 628                             (imap[n].br_startblock != DELAYSTARTBLOCK))
 629                                 return 0;
 630                         start_fsb += imap[n].br_blockcount;
 631                         count_fsb -= imap[n].br_blockcount;
 632                 }
 633         }
 634         *prealloc = 1;
 635         return 0;
 636 }
 637
 638 int
 639 xfs_iomap_write_delay(
 640         xfs_inode_t     *ip,
 641         xfs_off_t       offset,
 642         size_t          count,
 643         int             ioflag,
 644         xfs_bmbt_irec_t *ret_imap,
 645         int             *nmaps)
 646 {
 647         xfs_mount_t     *mp = ip->i_mount;
 648         xfs_iocore_t    *io = &ip->i_iocore;
 649         xfs_fileoff_t   offset_fsb;
 650         xfs_fileoff_t   last_fsb;
 651         xfs_off_t       aligned_offset;
 652         xfs_fileoff_t   ioalign;
 653         xfs_fsblock_t   firstblock;
 654         xfs_extlen_t    extsz;
 655         xfs_fsize_t     isize;
 656         int             nimaps;
 657         xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
 658         int             prealloc, fsynced = 0;
 659         int             error;
 660
 661         ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
 662
 663         /*
 664          * Make sure that the dquots are there. This doesn't hold
 665          * the ilock across a disk read.
 666          */
 667         error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
 668         if (error)
 669                 return XFS_ERROR(error);
 670
 671         if (XFS_IS_REALTIME_INODE(ip)) {
 672                 if (!(extsz = ip->i_d.di_extsize))
 673                         extsz = mp->m_sb.sb_rextsize;
 674         } else {
 675                 extsz = ip->i_d.di_extsize;
 676         }
 677
 678         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 679
 680 retry:
 681         isize = ip->i_d.di_size;
 682         if (io->io_new_size > isize)
 683                 isize = io->io_new_size;
 684
 685         error = xfs_iomap_eof_want_preallocate(mp, io, isize, offset, count,
 686                                 ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
 687         if (error)
 688                 return error;
 689
 690         if (prealloc) {
 691                 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
 692                 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
 693                 last_fsb = ioalign + mp->m_writeio_blocks;
 694         } else {
 695                 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
 696         }
 697
 698         if (prealloc || extsz) {
 699                 error = xfs_iomap_eof_align_last_fsb(mp, io, isize, extsz,
 700                                                         &last_fsb);
 701                 if (error)
 702                         return error;
 703         }
 704
 705         nimaps = XFS_WRITE_IMAPS;
 706         firstblock = NULLFSBLOCK;
 707         error = XFS_BMAPI(mp, NULL, io, offset_fsb,
 708                           (xfs_filblks_t)(last_fsb - offset_fsb),
 709                           XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
 710                           XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
 711                           &nimaps, NULL, NULL);
 712         if (error && (error != ENOSPC))
 713                 return XFS_ERROR(error);
 714
 715         /*
 716          * If bmapi returned us nothing, and if we didn't get back EDQUOT,
 717          * then we must have run out of space - flush delalloc, and retry..
 718          */
 719         if (nimaps == 0) {
 720                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
 721                                         io, offset, count);
 722                 if (xfs_flush_space(ip, &fsynced, &ioflag))
 723                         return XFS_ERROR(ENOSPC);
 724
 725                 error = 0;
 726                 goto retry;
 727         }
 728
 729         if (unlikely(!imap[0].br_startblock && !(io->io_flags & XFS_IOCORE_RT)))
 730                 return xfs_cmn_err_fsblock_zero(ip, &imap[0]);
 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(mp, tp, io, map_start_fsb, count_fsb,
 836                                         XFS_BMAPI_WRITE, &first_block, 1,
 837                                         imap, &nimaps, &free_list, NULL);
 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                 for (i = 0; i < nimaps; i++) {
 859                         if (unlikely(!imap[i].br_startblock &&
 860                                      !(io->io_flags & XFS_IOCORE_RT)))
 861                                 return xfs_cmn_err_fsblock_zero(ip, &imap[i]);
 862                         if ((offset_fsb >= imap[i].br_startoff) &&
 863                             (offset_fsb < (imap[i].br_startoff +
 864                                            imap[i].br_blockcount))) {
 865                                 *map = imap[i];
 866                                 *retmap = 1;
 867                                 XFS_STATS_INC(xs_xstrat_quick);
 868                                 return 0;
 869                         }
 870                         count_fsb -= imap[i].br_blockcount;
 871                 }
 872
 873                 /* So far we have not mapped the requested part of the
 874                  * file, just surrounding data, try again.
 875                  */
 876                 nimaps--;
 877                 map_start_fsb = imap[nimaps].br_startoff +
 878                                 imap[nimaps].br_blockcount;
 879         }
 880
 881 trans_cancel:
 882         xfs_bmap_cancel(&free_list);
 883         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
 884 error0:
 885         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 886         return XFS_ERROR(error);
 887 }
 888
 889 int
 890 xfs_iomap_write_unwritten(
 891         xfs_inode_t     *ip,
 892         xfs_off_t       offset,
 893         size_t          count)
 894 {
 895         xfs_mount_t     *mp = ip->i_mount;
 896         xfs_iocore_t    *io = &ip->i_iocore;
 897         xfs_fileoff_t   offset_fsb;
 898         xfs_filblks_t   count_fsb;
 899         xfs_filblks_t   numblks_fsb;
 900         xfs_fsblock_t   firstfsb;
 901         int             nimaps;
 902         xfs_trans_t     *tp;
 903         xfs_bmbt_irec_t imap;
 904         xfs_bmap_free_t free_list;
 905         uint            resblks;
 906         int             committed;
 907         int             error;
 908
 909         xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN,
 910                                 &ip->i_iocore, offset, count);
 911
 912         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 913         count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
 914         count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
 915
 916         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
 917
 918         do {
 919                 /*
 920                  * set up a transaction to convert the range of extents
 921                  * from unwritten to real. Do allocations in a loop until
 922                  * we have covered the range passed in.
 923                  */
 924
 925                 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
 926                 error = xfs_trans_reserve(tp, resblks,
 927                                 XFS_WRITE_LOG_RES(mp), 0,
 928                                 XFS_TRANS_PERM_LOG_RES,
 929                                 XFS_WRITE_LOG_COUNT);
 930                 if (error) {
 931                         xfs_trans_cancel(tp, 0);
 932                         return XFS_ERROR(error);
 933                 }
 934
 935                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 936                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 937                 xfs_trans_ihold(tp, ip);
 938
 939                 /*
 940                  * Modify the unwritten extent state of the buffer.
 941                  */
 942                 XFS_BMAP_INIT(&free_list, &firstfsb);
 943                 nimaps = 1;
 944                 error = XFS_BMAPI(mp, tp, io, offset_fsb, count_fsb,
 945                                   XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb,
 946                                   1, &imap, &nimaps, &free_list, NULL);
 947                 if (error)
 948                         goto error_on_bmapi_transaction;
 949
 950                 error = xfs_bmap_finish(&(tp), &(free_list),
 951                                 firstfsb, &committed);
 952                 if (error)
 953                         goto error_on_bmapi_transaction;
 954
 955                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
 956                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 957                 if (error)
 958                         return XFS_ERROR(error);
 959
 960                 if (unlikely(!imap.br_startblock &&
 961                              !(io->io_flags & XFS_IOCORE_RT)))
 962                         return xfs_cmn_err_fsblock_zero(ip, &imap);
 963
 964                 if ((numblks_fsb = imap.br_blockcount) == 0) {
 965                         /*
 966                          * The numblks_fsb value should always get
 967                          * smaller, otherwise the loop is stuck.
 968                          */
 969                         ASSERT(imap.br_blockcount);
 970                         break;
 971                 }
 972                 offset_fsb += numblks_fsb;
 973                 count_fsb -= numblks_fsb;
 974         } while (count_fsb > 0);
 975
 976         return 0;
 977
 978 error_on_bmapi_transaction:
 979         xfs_bmap_cancel(&free_list);
 980         xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
 981         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 982         return XFS_ERROR(error);
 983 }