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

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