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         int             pbm;
 139         xfs_fsblock_t   start_block;
 140
 141         mp = io->io_mount;
 142
 143         for (pbm = 0; imaps && pbm < iomaps; imaps--, iomapp++, imap++, pbm++) {
 144                 iomapp->iomap_offset = XFS_FSB_TO_B(mp, imap->br_startoff);
 145                 iomapp->iomap_delta = offset - iomapp->iomap_offset;
 146                 iomapp->iomap_bsize = XFS_FSB_TO_B(mp, imap->br_blockcount);
 147                 iomapp->iomap_flags = flags;
 148
 149                 if (io->io_flags & XFS_IOCORE_RT) {
 150                         iomapp->iomap_flags |= IOMAP_REALTIME;
 151                         iomapp->iomap_target = mp->m_rtdev_targp;
 152                 } else {
 153                         iomapp->iomap_target = mp->m_ddev_targp;
 154                 }
 155                 start_block = imap->br_startblock;
 156                 if (start_block == HOLESTARTBLOCK) {
 157                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
 158                         iomapp->iomap_flags |= IOMAP_HOLE;
 159                 } else if (start_block == DELAYSTARTBLOCK) {
 160                         iomapp->iomap_bn = IOMAP_DADDR_NULL;
 161                         iomapp->iomap_flags |= IOMAP_DELAY;
 162                 } else {
 163                         iomapp->iomap_bn = XFS_FSB_TO_DB_IO(io, start_block);
 164                         if (ISUNWRITTEN(imap))
 165                                 iomapp->iomap_flags |= IOMAP_UNWRITTEN;
 166                 }
 167
 168                 offset += iomapp->iomap_bsize - iomapp->iomap_delta;
 169         }
 170         return pbm;     /* Return the number filled */
 171 }
 172
 173 int
 174 xfs_iomap(
 175         xfs_iocore_t    *io,
 176         xfs_off_t       offset,
 177         ssize_t         count,
 178         int             flags,
 179         xfs_iomap_t     *iomapp,
 180         int             *niomaps)
 181 {
 182         xfs_mount_t     *mp = io->io_mount;
 183         xfs_fileoff_t   offset_fsb, end_fsb;
 184         int             error = 0;
 185         int             lockmode = 0;
 186         xfs_bmbt_irec_t imap;
 187         int             nimaps = 1;
 188         int             bmapi_flags = 0;
 189         int             iomap_flags = 0;
 190
 191         if (XFS_FORCED_SHUTDOWN(mp))
 192                 return XFS_ERROR(EIO);
 193
 194         switch (flags &
 195                 (BMAPI_READ | BMAPI_WRITE | BMAPI_ALLOCATE |
 196                  BMAPI_UNWRITTEN | BMAPI_DEVICE)) {
 197         case BMAPI_READ:
 198                 xfs_iomap_enter_trace(XFS_IOMAP_READ_ENTER, io, offset, count);
 199                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
 200                 bmapi_flags = XFS_BMAPI_ENTIRE;
 201                 break;
 202         case BMAPI_WRITE:
 203                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_ENTER, io, offset, count);
 204                 lockmode = XFS_ILOCK_EXCL|XFS_EXTSIZE_WR;
 205                 if (flags & BMAPI_IGNSTATE)
 206                         bmapi_flags |= XFS_BMAPI_IGSTATE|XFS_BMAPI_ENTIRE;
 207                 XFS_ILOCK(mp, io, lockmode);
 208                 break;
 209         case BMAPI_ALLOCATE:
 210                 xfs_iomap_enter_trace(XFS_IOMAP_ALLOC_ENTER, io, offset, count);
 211                 lockmode = XFS_ILOCK_SHARED|XFS_EXTSIZE_RD;
 212                 bmapi_flags = XFS_BMAPI_ENTIRE;
 213                 /* Attempt non-blocking lock */
 214                 if (flags & BMAPI_TRYLOCK) {
 215                         if (!XFS_ILOCK_NOWAIT(mp, io, lockmode))
 216                                 return XFS_ERROR(EAGAIN);
 217                 } else {
 218                         XFS_ILOCK(mp, io, lockmode);
 219                 }
 220                 break;
 221         case BMAPI_UNWRITTEN:
 222                 goto phase2;
 223         case BMAPI_DEVICE:
 224                 lockmode = XFS_LCK_MAP_SHARED(mp, io);
 225                 iomapp->iomap_target = io->io_flags & XFS_IOCORE_RT ?
 226                         mp->m_rtdev_targp : mp->m_ddev_targp;
 227                 error = 0;
 228                 *niomaps = 1;
 229                 goto out;
 230         default:
 231                 BUG();
 232         }
 233
 234         ASSERT(offset <= mp->m_maxioffset);
 235         if ((xfs_fsize_t)offset + count > mp->m_maxioffset)
 236                 count = mp->m_maxioffset - offset;
 237         end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
 238         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 239
 240         error = XFS_BMAPI(mp, NULL, io, offset_fsb,
 241                         (xfs_filblks_t)(end_fsb - offset_fsb),
 242                         bmapi_flags,  NULL, 0, &imap,
 243                         &nimaps, NULL, NULL);
 244
 245         if (error)
 246                 goto out;
 247
 248 phase2:
 249         switch (flags & (BMAPI_WRITE|BMAPI_ALLOCATE|BMAPI_UNWRITTEN)) {
 250         case BMAPI_WRITE:
 251                 /* If we found an extent, return it */
 252                 if (nimaps &&
 253                     (imap.br_startblock != HOLESTARTBLOCK) &&
 254                     (imap.br_startblock != DELAYSTARTBLOCK)) {
 255                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
 256                                         offset, count, iomapp, &imap, flags);
 257                         break;
 258                 }
 259
 260                 if (flags & (BMAPI_DIRECT|BMAPI_MMAP)) {
 261                         error = XFS_IOMAP_WRITE_DIRECT(mp, io, offset,
 262                                         count, flags, &imap, &nimaps, nimaps);
 263                 } else {
 264                         error = XFS_IOMAP_WRITE_DELAY(mp, io, offset, count,
 265                                         flags, &imap, &nimaps);
 266                 }
 267                 if (!error) {
 268                         xfs_iomap_map_trace(XFS_IOMAP_ALLOC_MAP, io,
 269                                         offset, count, iomapp, &imap, flags);
 270                 }
 271                 iomap_flags = IOMAP_NEW;
 272                 break;
 273         case BMAPI_ALLOCATE:
 274                 /* If we found an extent, return it */
 275                 XFS_IUNLOCK(mp, io, lockmode);
 276                 lockmode = 0;
 277
 278                 if (nimaps && !ISNULLSTARTBLOCK(imap.br_startblock)) {
 279                         xfs_iomap_map_trace(XFS_IOMAP_WRITE_MAP, io,
 280                                         offset, count, iomapp, &imap, flags);
 281                         break;
 282                 }
 283
 284                 error = XFS_IOMAP_WRITE_ALLOCATE(mp, io, offset, count,
 285                                                  &imap, &nimaps);
 286                 break;
 287         case BMAPI_UNWRITTEN:
 288                 lockmode = 0;
 289                 error = XFS_IOMAP_WRITE_UNWRITTEN(mp, io, offset, count);
 290                 nimaps = 0;
 291                 break;
 292         }
 293
 294         if (nimaps) {
 295                 *niomaps = xfs_imap_to_bmap(io, offset, &imap,
 296                                             iomapp, nimaps, *niomaps, iomap_flags);
 297         } else if (niomaps) {
 298                 *niomaps = 0;
 299         }
 300
 301 out:
 302         if (lockmode)
 303                 XFS_IUNLOCK(mp, io, lockmode);
 304         return XFS_ERROR(error);
 305 }
 306
 307 STATIC int
 308 xfs_iomap_eof_align_last_fsb(
 309         xfs_mount_t     *mp,
 310         xfs_iocore_t    *io,
 311         xfs_fsize_t     isize,
 312         xfs_extlen_t    extsize,
 313         xfs_fileoff_t   *last_fsb)
 314 {
 315         xfs_fileoff_t   new_last_fsb = 0;
 316         xfs_extlen_t    align;
 317         int             eof, error;
 318
 319         if (io->io_flags & XFS_IOCORE_RT)
 320                 ;
 321         /*
 322          * If mounted with the "-o swalloc" option, roundup the allocation
 323          * request to a stripe width boundary if the file size is >=
 324          * stripe width and we are allocating past the allocation eof.
 325          */
 326         else if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC) &&
 327                 (isize >= XFS_FSB_TO_B(mp, mp->m_swidth)))
 328                 new_last_fsb = roundup_64(*last_fsb, mp->m_swidth);
 329         /*
 330          * Roundup the allocation request to a stripe unit (m_dalign) boundary
 331          * if the file size is >= stripe unit size, and we are allocating past
 332          * the allocation eof.
 333          */
 334         else if (mp->m_dalign && (isize >= XFS_FSB_TO_B(mp, mp->m_dalign)))
 335                 new_last_fsb = roundup_64(*last_fsb, mp->m_dalign);
 336
 337         /*
 338          * Always round up the allocation request to an extent boundary
 339          * (when file on a real-time subvolume or has di_extsize hint).
 340          */
 341         if (extsize) {
 342                 if (new_last_fsb)
 343                         align = roundup_64(new_last_fsb, extsize);
 344                 else
 345                         align = extsize;
 346                 new_last_fsb = roundup_64(*last_fsb, align);
 347         }
 348
 349         if (new_last_fsb) {
 350                 error = XFS_BMAP_EOF(mp, io, new_last_fsb, XFS_DATA_FORK, &eof);
 351                 if (error)
 352                         return error;
 353                 if (eof)
 354                         *last_fsb = new_last_fsb;
 355         }
 356         return 0;
 357 }
 358
 359 STATIC int
 360 xfs_flush_space(
 361         xfs_inode_t     *ip,
 362         int             *fsynced,
 363         int             *ioflags)
 364 {
 365         switch (*fsynced) {
 366         case 0:
 367                 if (ip->i_delayed_blks) {
 368                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 369                         xfs_flush_inode(ip);
 370                         xfs_ilock(ip, XFS_ILOCK_EXCL);
 371                         *fsynced = 1;
 372                 } else {
 373                         *ioflags |= BMAPI_SYNC;
 374                         *fsynced = 2;
 375                 }
 376                 return 0;
 377         case 1:
 378                 *fsynced = 2;
 379                 *ioflags |= BMAPI_SYNC;
 380                 return 0;
 381         case 2:
 382                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 383                 xfs_flush_device(ip);
 384                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 385                 *fsynced = 3;
 386                 return 0;
 387         }
 388         return 1;
 389 }
 390
 391 STATIC int
 392 xfs_cmn_err_fsblock_zero(
 393         xfs_inode_t     *ip,
 394         xfs_bmbt_irec_t *imap)
 395 {
 396         xfs_cmn_err(XFS_PTAG_FSBLOCK_ZERO, CE_ALERT, ip->i_mount,
 397                         "Access to block zero in inode %llu "
 398                         "start_block: %llx start_off: %llx "
 399                         "blkcnt: %llx extent-state: %x\n",
 400                 (unsigned long long)ip->i_ino,
 401                 (unsigned long long)imap->br_startblock,
 402                 (unsigned long long)imap->br_startoff,
 403                 (unsigned long long)imap->br_blockcount,
 404                 imap->br_state);
 405         return EFSCORRUPTED;
 406 }
 407
 408 int
 409 xfs_iomap_write_direct(
 410         xfs_inode_t     *ip,
 411         xfs_off_t       offset,
 412         size_t          count,
 413         int             flags,
 414         xfs_bmbt_irec_t *ret_imap,
 415         int             *nmaps,
 416         int             found)
 417 {
 418         xfs_mount_t     *mp = ip->i_mount;
 419         xfs_iocore_t    *io = &ip->i_iocore;
 420         xfs_fileoff_t   offset_fsb;
 421         xfs_fileoff_t   last_fsb;
 422         xfs_filblks_t   count_fsb, resaligned;
 423         xfs_fsblock_t   firstfsb;
 424         xfs_extlen_t    extsz, temp;
 425         xfs_fsize_t     isize;
 426         int             nimaps;
 427         int             bmapi_flag;
 428         int             quota_flag;
 429         int             rt;
 430         xfs_trans_t     *tp;
 431         xfs_bmbt_irec_t imap;
 432         xfs_bmap_free_t free_list;
 433         uint            qblocks, resblks, resrtextents;
 434         int             committed;
 435         int             error;
 436
 437         /*
 438          * Make sure that the dquots are there. This doesn't hold
 439          * the ilock across a disk read.
 440          */
 441         error = XFS_QM_DQATTACH(ip->i_mount, ip, XFS_QMOPT_ILOCKED);
 442         if (error)
 443                 return XFS_ERROR(error);
 444
 445         rt = XFS_IS_REALTIME_INODE(ip);
 446         extsz = xfs_get_extsz_hint(ip);
 447
 448         isize = ip->i_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_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(mp, tp, io, offset_fsb, count_fsb, bmapi_flag,
 523                 &firstfsb, 0, &imap, &nimaps, &free_list, NULL);
 524         if (error)
 525                 goto error0;
 526
 527         /*
 528          * Complete the transaction
 529          */
 530         error = xfs_bmap_finish(&tp, &free_list, &committed);
 531         if (error)
 532                 goto error0;
 533         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 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         if (unlikely(!imap.br_startblock && !(io->io_flags & XFS_IOCORE_RT))) {
 546                 error = xfs_cmn_err_fsblock_zero(ip, &imap);
 547                 goto error_out;
 548         }
 549
 550         *ret_imap = imap;
 551         *nmaps = 1;
 552         return 0;
 553
 554 error0: /* Cancel bmap, unlock inode, unreserve quota blocks, cancel trans */
 555         xfs_bmap_cancel(&free_list);
 556         XFS_TRANS_UNRESERVE_QUOTA_NBLKS(mp, tp, ip, qblocks, 0, quota_flag);
 557
 558 error1: /* Just cancel transaction */
 559         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
 560         *nmaps = 0;     /* nothing set-up here */
 561
 562 error_out:
 563         return XFS_ERROR(error);
 564 }
 565
 566 /*
 567  * If the caller is doing a write at the end of the file,
 568  * then extend the allocation out to the file system's write
 569  * iosize.  We clean up any extra space left over when the
 570  * file is closed in xfs_inactive().
 571  *
 572  * For sync writes, we are flushing delayed allocate space to
 573  * try to make additional space available for allocation near
 574  * the filesystem full boundary - preallocation hurts in that
 575  * situation, of course.
 576  */
 577 STATIC int
 578 xfs_iomap_eof_want_preallocate(
 579         xfs_mount_t     *mp,
 580         xfs_iocore_t    *io,
 581         xfs_fsize_t     isize,
 582         xfs_off_t       offset,
 583         size_t          count,
 584         int             ioflag,
 585         xfs_bmbt_irec_t *imap,
 586         int             nimaps,
 587         int             *prealloc)
 588 {
 589         xfs_fileoff_t   start_fsb;
 590         xfs_filblks_t   count_fsb;
 591         xfs_fsblock_t   firstblock;
 592         int             n, error, imaps;
 593
 594         *prealloc = 0;
 595         if ((ioflag & BMAPI_SYNC) || (offset + count) <= isize)
 596                 return 0;
 597
 598         /*
 599          * If there are any real blocks past eof, then don't
 600          * do any speculative allocation.
 601          */
 602         start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1)));
 603         count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
 604         while (count_fsb > 0) {
 605                 imaps = nimaps;
 606                 firstblock = NULLFSBLOCK;
 607                 error = XFS_BMAPI(mp, NULL, io, start_fsb, count_fsb, 0,
 608                                   &firstblock, 0, imap, &imaps, NULL, NULL);
 609                 if (error)
 610                         return error;
 611                 for (n = 0; n < imaps; n++) {
 612                         if ((imap[n].br_startblock != HOLESTARTBLOCK) &&
 613                             (imap[n].br_startblock != DELAYSTARTBLOCK))
 614                                 return 0;
 615                         start_fsb += imap[n].br_blockcount;
 616                         count_fsb -= imap[n].br_blockcount;
 617                 }
 618         }
 619         *prealloc = 1;
 620         return 0;
 621 }
 622
 623 int
 624 xfs_iomap_write_delay(
 625         xfs_inode_t     *ip,
 626         xfs_off_t       offset,
 627         size_t          count,
 628         int             ioflag,
 629         xfs_bmbt_irec_t *ret_imap,
 630         int             *nmaps)
 631 {
 632         xfs_mount_t     *mp = ip->i_mount;
 633         xfs_iocore_t    *io = &ip->i_iocore;
 634         xfs_fileoff_t   offset_fsb;
 635         xfs_fileoff_t   last_fsb;
 636         xfs_off_t       aligned_offset;
 637         xfs_fileoff_t   ioalign;
 638         xfs_fsblock_t   firstblock;
 639         xfs_extlen_t    extsz;
 640         xfs_fsize_t     isize;
 641         int             nimaps;
 642         xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
 643         int             prealloc, fsynced = 0;
 644         int             error;
 645
 646         ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
 647
 648         /*
 649          * Make sure that the dquots are there. This doesn't hold
 650          * the ilock across a disk read.
 651          */
 652         error = XFS_QM_DQATTACH(mp, ip, XFS_QMOPT_ILOCKED);
 653         if (error)
 654                 return XFS_ERROR(error);
 655
 656         extsz = xfs_get_extsz_hint(ip);
 657         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 658
 659 retry:
 660         isize = ip->i_size;
 661         if (io->io_new_size > isize)
 662                 isize = io->io_new_size;
 663
 664         error = xfs_iomap_eof_want_preallocate(mp, io, isize, offset, count,
 665                                 ioflag, imap, XFS_WRITE_IMAPS, &prealloc);
 666         if (error)
 667                 return error;
 668
 669         if (prealloc) {
 670                 aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1));
 671                 ioalign = XFS_B_TO_FSBT(mp, aligned_offset);
 672                 last_fsb = ioalign + mp->m_writeio_blocks;
 673         } else {
 674                 last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
 675         }
 676
 677         if (prealloc || extsz) {
 678                 error = xfs_iomap_eof_align_last_fsb(mp, io, isize, extsz,
 679                                                         &last_fsb);
 680                 if (error)
 681                         return error;
 682         }
 683
 684         nimaps = XFS_WRITE_IMAPS;
 685         firstblock = NULLFSBLOCK;
 686         error = XFS_BMAPI(mp, NULL, io, offset_fsb,
 687                           (xfs_filblks_t)(last_fsb - offset_fsb),
 688                           XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
 689                           XFS_BMAPI_ENTIRE, &firstblock, 1, imap,
 690                           &nimaps, NULL, NULL);
 691         if (error && (error != ENOSPC))
 692                 return XFS_ERROR(error);
 693
 694         /*
 695          * If bmapi returned us nothing, and if we didn't get back EDQUOT,
 696          * then we must have run out of space - flush delalloc, and retry..
 697          */
 698         if (nimaps == 0) {
 699                 xfs_iomap_enter_trace(XFS_IOMAP_WRITE_NOSPACE,
 700                                         io, offset, count);
 701                 if (xfs_flush_space(ip, &fsynced, &ioflag))
 702                         return XFS_ERROR(ENOSPC);
 703
 704                 error = 0;
 705                 goto retry;
 706         }
 707
 708         if (unlikely(!imap[0].br_startblock && !(io->io_flags & XFS_IOCORE_RT)))
 709                 return xfs_cmn_err_fsblock_zero(ip, &imap[0]);
 710
 711         *ret_imap = imap[0];
 712         *nmaps = 1;
 713
 714         return 0;
 715 }
 716
 717 /*
 718  * Pass in a delayed allocate extent, convert it to real extents;
 719  * return to the caller the extent we create which maps on top of
 720  * the originating callers request.
 721  *
 722  * Called without a lock on the inode.
 723  */
 724 int
 725 xfs_iomap_write_allocate(
 726         xfs_inode_t     *ip,
 727         xfs_off_t       offset,
 728         size_t          count,
 729         xfs_bmbt_irec_t *map,
 730         int             *retmap)
 731 {
 732         xfs_mount_t     *mp = ip->i_mount;
 733         xfs_iocore_t    *io = &ip->i_iocore;
 734         xfs_fileoff_t   offset_fsb, last_block;
 735         xfs_fileoff_t   end_fsb, map_start_fsb;
 736         xfs_fsblock_t   first_block;
 737         xfs_bmap_free_t free_list;
 738         xfs_filblks_t   count_fsb;
 739         xfs_bmbt_irec_t imap[XFS_STRAT_WRITE_IMAPS];
 740         xfs_trans_t     *tp;
 741         int             i, nimaps, committed;
 742         int             error = 0;
 743         int             nres;
 744
 745         *retmap = 0;
 746
 747         /*
 748          * Make sure that the dquots are there.
 749          */
 750         if ((error = XFS_QM_DQATTACH(mp, ip, 0)))
 751                 return XFS_ERROR(error);
 752
 753         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 754         count_fsb = map->br_blockcount;
 755         map_start_fsb = map->br_startoff;
 756
 757         XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb));
 758
 759         while (count_fsb != 0) {
 760                 /*
 761                  * Set up a transaction with which to allocate the
 762                  * backing store for the file.  Do allocations in a
 763                  * loop until we get some space in the range we are
 764                  * interested in.  The other space that might be allocated
 765                  * is in the delayed allocation extent on which we sit
 766                  * but before our buffer starts.
 767                  */
 768
 769                 nimaps = 0;
 770                 while (nimaps == 0) {
 771                         tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
 772                         tp->t_flags |= XFS_TRANS_RESERVE;
 773                         nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK);
 774                         error = xfs_trans_reserve(tp, nres,
 775                                         XFS_WRITE_LOG_RES(mp),
 776                                         0, XFS_TRANS_PERM_LOG_RES,
 777                                         XFS_WRITE_LOG_COUNT);
 778                         if (error) {
 779                                 xfs_trans_cancel(tp, 0);
 780                                 return XFS_ERROR(error);
 781                         }
 782                         xfs_ilock(ip, XFS_ILOCK_EXCL);
 783                         xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 784                         xfs_trans_ihold(tp, ip);
 785
 786                         XFS_BMAP_INIT(&free_list, &first_block);
 787
 788                         nimaps = XFS_STRAT_WRITE_IMAPS;
 789                         /*
 790                          * Ensure we don't go beyond eof - it is possible
 791                          * the extents changed since we did the read call,
 792                          * we dropped the ilock in the interim.
 793                          */
 794
 795                         end_fsb = XFS_B_TO_FSB(mp, ip->i_size);
 796                         xfs_bmap_last_offset(NULL, ip, &last_block,
 797                                 XFS_DATA_FORK);
 798                         last_block = XFS_FILEOFF_MAX(last_block, end_fsb);
 799                         if ((map_start_fsb + count_fsb) > last_block) {
 800                                 count_fsb = last_block - map_start_fsb;
 801                                 if (count_fsb == 0) {
 802                                         error = EAGAIN;
 803                                         goto trans_cancel;
 804                                 }
 805                         }
 806
 807                         /* Go get the actual blocks */
 808                         error = XFS_BMAPI(mp, tp, io, map_start_fsb, count_fsb,
 809                                         XFS_BMAPI_WRITE, &first_block, 1,
 810                                         imap, &nimaps, &free_list, NULL);
 811                         if (error)
 812                                 goto trans_cancel;
 813
 814                         error = xfs_bmap_finish(&tp, &free_list, &committed);
 815                         if (error)
 816                                 goto trans_cancel;
 817
 818                         error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 819                         if (error)
 820                                 goto error0;
 821
 822                         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 823                 }
 824
 825                 /*
 826                  * See if we were able to allocate an extent that
 827                  * covers at least part of the callers request
 828                  */
 829                 for (i = 0; i < nimaps; i++) {
 830                         if (unlikely(!imap[i].br_startblock &&
 831                                      !(io->io_flags & XFS_IOCORE_RT)))
 832                                 return xfs_cmn_err_fsblock_zero(ip, &imap[i]);
 833                         if ((offset_fsb >= imap[i].br_startoff) &&
 834                             (offset_fsb < (imap[i].br_startoff +
 835                                            imap[i].br_blockcount))) {
 836                                 *map = imap[i];
 837                                 *retmap = 1;
 838                                 XFS_STATS_INC(xs_xstrat_quick);
 839                                 return 0;
 840                         }
 841                         count_fsb -= imap[i].br_blockcount;
 842                 }
 843
 844                 /* So far we have not mapped the requested part of the
 845                  * file, just surrounding data, try again.
 846                  */
 847                 nimaps--;
 848                 map_start_fsb = imap[nimaps].br_startoff +
 849                                 imap[nimaps].br_blockcount;
 850         }
 851
 852 trans_cancel:
 853         xfs_bmap_cancel(&free_list);
 854         xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
 855 error0:
 856         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 857         return XFS_ERROR(error);
 858 }
 859
 860 int
 861 xfs_iomap_write_unwritten(
 862         xfs_inode_t     *ip,
 863         xfs_off_t       offset,
 864         size_t          count)
 865 {
 866         xfs_mount_t     *mp = ip->i_mount;
 867         xfs_iocore_t    *io = &ip->i_iocore;
 868         xfs_fileoff_t   offset_fsb;
 869         xfs_filblks_t   count_fsb;
 870         xfs_filblks_t   numblks_fsb;
 871         xfs_fsblock_t   firstfsb;
 872         int             nimaps;
 873         xfs_trans_t     *tp;
 874         xfs_bmbt_irec_t imap;
 875         xfs_bmap_free_t free_list;
 876         uint            resblks;
 877         int             committed;
 878         int             error;
 879
 880         xfs_iomap_enter_trace(XFS_IOMAP_UNWRITTEN,
 881                                 &ip->i_iocore, offset, count);
 882
 883         offset_fsb = XFS_B_TO_FSBT(mp, offset);
 884         count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
 885         count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
 886
 887         resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
 888
 889         do {
 890                 /*
 891                  * set up a transaction to convert the range of extents
 892                  * from unwritten to real. Do allocations in a loop until
 893                  * we have covered the range passed in.
 894                  */
 895                 tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);
 896                 tp->t_flags |= XFS_TRANS_RESERVE;
 897                 error = xfs_trans_reserve(tp, resblks,
 898                                 XFS_WRITE_LOG_RES(mp), 0,
 899                                 XFS_TRANS_PERM_LOG_RES,
 900                                 XFS_WRITE_LOG_COUNT);
 901                 if (error) {
 902                         xfs_trans_cancel(tp, 0);
 903                         return XFS_ERROR(error);
 904                 }
 905
 906                 xfs_ilock(ip, XFS_ILOCK_EXCL);
 907                 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 908                 xfs_trans_ihold(tp, ip);
 909
 910                 /*
 911                  * Modify the unwritten extent state of the buffer.
 912                  */
 913                 XFS_BMAP_INIT(&free_list, &firstfsb);
 914                 nimaps = 1;
 915                 error = XFS_BMAPI(mp, tp, io, offset_fsb, count_fsb,
 916                                   XFS_BMAPI_WRITE|XFS_BMAPI_CONVERT, &firstfsb,
 917                                   1, &imap, &nimaps, &free_list, NULL);
 918                 if (error)
 919                         goto error_on_bmapi_transaction;
 920
 921                 error = xfs_bmap_finish(&(tp), &(free_list), &committed);
 922                 if (error)
 923                         goto error_on_bmapi_transaction;
 924
 925                 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
 926                 xfs_iunlock(ip, XFS_ILOCK_EXCL);
 927                 if (error)
 928                         return XFS_ERROR(error);
 929
 930                 if (unlikely(!imap.br_startblock &&
 931                              !(io->io_flags & XFS_IOCORE_RT)))
 932                         return xfs_cmn_err_fsblock_zero(ip, &imap);
 933
 934                 if ((numblks_fsb = imap.br_blockcount) == 0) {
 935                         /*
 936                          * The numblks_fsb value should always get
 937                          * smaller, otherwise the loop is stuck.
 938                          */
 939                         ASSERT(imap.br_blockcount);
 940                         break;
 941                 }
 942                 offset_fsb += numblks_fsb;
 943                 count_fsb -= numblks_fsb;
 944         } while (count_fsb > 0);
 945
 946         return 0;
 947
 948 error_on_bmapi_transaction:
 949         xfs_bmap_cancel(&free_list);
 950         xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT));
 951         xfs_iunlock(ip, XFS_ILOCK_EXCL);
 952         return XFS_ERROR(error);
 953 }