fs/xfs/xfs_ialloc.c

   1 /*
   2  * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #include "xfs.h"
  19 #include "xfs_fs.h"
  20 #include "xfs_types.h"
  21 #include "xfs_bit.h"
  22 #include "xfs_log.h"
  23 #include "xfs_inum.h"
  24 #include "xfs_trans.h"
  25 #include "xfs_sb.h"
  26 #include "xfs_ag.h"
  27 #include "xfs_dir2.h"
  28 #include "xfs_dmapi.h"
  29 #include "xfs_mount.h"
  30 #include "xfs_bmap_btree.h"
  31 #include "xfs_alloc_btree.h"
  32 #include "xfs_ialloc_btree.h"
  33 #include "xfs_dir2_sf.h"
  34 #include "xfs_attr_sf.h"
  35 #include "xfs_dinode.h"
  36 #include "xfs_inode.h"
  37 #include "xfs_btree.h"
  38 #include "xfs_ialloc.h"
  39 #include "xfs_alloc.h"
  40 #include "xfs_rtalloc.h"
  41 #include "xfs_error.h"
  42 #include "xfs_bmap.h"
  43
  44 /*
  45  * Log specified fields for the inode given by bp and off.
  46  */
  47 STATIC void
  48 xfs_ialloc_log_di(
  49         xfs_trans_t     *tp,            /* transaction pointer */
  50         xfs_buf_t       *bp,            /* inode buffer */
  51         int             off,            /* index of inode in buffer */
  52         int             fields)         /* bitmask of fields to log */
  53 {
  54         int                     first;          /* first byte number */
  55         int                     ioffset;        /* off in bytes */
  56         int                     last;           /* last byte number */
  57         xfs_mount_t             *mp;            /* mount point structure */
  58         static const short      offsets[] = {   /* field offsets */
  59                                                 /* keep in sync with bits */
  60                 offsetof(xfs_dinode_core_t, di_magic),
  61                 offsetof(xfs_dinode_core_t, di_mode),
  62                 offsetof(xfs_dinode_core_t, di_version),
  63                 offsetof(xfs_dinode_core_t, di_format),
  64                 offsetof(xfs_dinode_core_t, di_onlink),
  65                 offsetof(xfs_dinode_core_t, di_uid),
  66                 offsetof(xfs_dinode_core_t, di_gid),
  67                 offsetof(xfs_dinode_core_t, di_nlink),
  68                 offsetof(xfs_dinode_core_t, di_projid),
  69                 offsetof(xfs_dinode_core_t, di_pad),
  70                 offsetof(xfs_dinode_core_t, di_atime),
  71                 offsetof(xfs_dinode_core_t, di_mtime),
  72                 offsetof(xfs_dinode_core_t, di_ctime),
  73                 offsetof(xfs_dinode_core_t, di_size),
  74                 offsetof(xfs_dinode_core_t, di_nblocks),
  75                 offsetof(xfs_dinode_core_t, di_extsize),
  76                 offsetof(xfs_dinode_core_t, di_nextents),
  77                 offsetof(xfs_dinode_core_t, di_anextents),
  78                 offsetof(xfs_dinode_core_t, di_forkoff),
  79                 offsetof(xfs_dinode_core_t, di_aformat),
  80                 offsetof(xfs_dinode_core_t, di_dmevmask),
  81                 offsetof(xfs_dinode_core_t, di_dmstate),
  82                 offsetof(xfs_dinode_core_t, di_flags),
  83                 offsetof(xfs_dinode_core_t, di_gen),
  84                 offsetof(xfs_dinode_t, di_next_unlinked),
  85                 offsetof(xfs_dinode_t, di_u),
  86                 offsetof(xfs_dinode_t, di_a),
  87                 sizeof(xfs_dinode_t)
  88         };
  89
  90
  91         ASSERT(offsetof(xfs_dinode_t, di_core) == 0);
  92         ASSERT((fields & (XFS_DI_U|XFS_DI_A)) == 0);
  93         mp = tp->t_mountp;
  94         /*
  95          * Get the inode-relative first and last bytes for these fields
  96          */
  97         xfs_btree_offsets(fields, offsets, XFS_DI_NUM_BITS, &first, &last);
  98         /*
  99          * Convert to buffer offsets and log it.
 100          */
 101         ioffset = off << mp->m_sb.sb_inodelog;
 102         first += ioffset;
 103         last += ioffset;
 104         xfs_trans_log_buf(tp, bp, first, last);
 105 }
 106
 107 /*
 108  * Allocation group level functions.
 109  */
 110 static inline int
 111 xfs_ialloc_cluster_alignment(
 112         xfs_alloc_arg_t *args)
 113 {
 114         if (xfs_sb_version_hasalign(&args->mp->m_sb) &&
 115             args->mp->m_sb.sb_inoalignmt >=
 116              XFS_B_TO_FSBT(args->mp, XFS_INODE_CLUSTER_SIZE(args->mp)))
 117                 return args->mp->m_sb.sb_inoalignmt;
 118         return 1;
 119 }
 120
 121 /*
 122  * Allocate new inodes in the allocation group specified by agbp.
 123  * Return 0 for success, else error code.
 124  */
 125 STATIC int                              /* error code or 0 */
 126 xfs_ialloc_ag_alloc(
 127         xfs_trans_t     *tp,            /* transaction pointer */
 128         xfs_buf_t       *agbp,          /* alloc group buffer */
 129         int             *alloc)
 130 {
 131         xfs_agi_t       *agi;           /* allocation group header */
 132         xfs_alloc_arg_t args;           /* allocation argument structure */
 133         int             blks_per_cluster;  /* fs blocks per inode cluster */
 134         xfs_btree_cur_t *cur;           /* inode btree cursor */
 135         xfs_daddr_t     d;              /* disk addr of buffer */
 136         xfs_agnumber_t  agno;
 137         int             error;
 138         xfs_buf_t       *fbuf;          /* new free inodes' buffer */
 139         xfs_dinode_t    *free;          /* new free inode structure */
 140         int             i;              /* inode counter */
 141         int             j;              /* block counter */
 142         int             nbufs;          /* num bufs of new inodes */
 143         xfs_agino_t     newino;         /* new first inode's number */
 144         xfs_agino_t     newlen;         /* new number of inodes */
 145         int             ninodes;        /* num inodes per buf */
 146         xfs_agino_t     thisino;        /* current inode number, for loop */
 147         int             version;        /* inode version number to use */
 148         int             isaligned = 0;  /* inode allocation at stripe unit */
 149                                         /* boundary */
 150         unsigned int    gen;
 151
 152         args.tp = tp;
 153         args.mp = tp->t_mountp;
 154
 155         /*
 156          * Locking will ensure that we don't have two callers in here
 157          * at one time.
 158          */
 159         newlen = XFS_IALLOC_INODES(args.mp);
 160         if (args.mp->m_maxicount &&
 161             args.mp->m_sb.sb_icount + newlen > args.mp->m_maxicount)
 162                 return XFS_ERROR(ENOSPC);
 163         args.minlen = args.maxlen = XFS_IALLOC_BLOCKS(args.mp);
 164         /*
 165          * First try to allocate inodes contiguous with the last-allocated
 166          * chunk of inodes.  If the filesystem is striped, this will fill
 167          * an entire stripe unit with inodes.
 168          */
 169         agi = XFS_BUF_TO_AGI(agbp);
 170         newino = be32_to_cpu(agi->agi_newino);
 171         args.agbno = XFS_AGINO_TO_AGBNO(args.mp, newino) +
 172                         XFS_IALLOC_BLOCKS(args.mp);
 173         if (likely(newino != NULLAGINO &&
 174                   (args.agbno < be32_to_cpu(agi->agi_length)))) {
 175                 args.fsbno = XFS_AGB_TO_FSB(args.mp,
 176                                 be32_to_cpu(agi->agi_seqno), args.agbno);
 177                 args.type = XFS_ALLOCTYPE_THIS_BNO;
 178                 args.mod = args.total = args.wasdel = args.isfl =
 179                         args.userdata = args.minalignslop = 0;
 180                 args.prod = 1;
 181
 182                 /*
 183                  * We need to take into account alignment here to ensure that
 184                  * we don't modify the free list if we fail to have an exact
 185                  * block. If we don't have an exact match, and every oher
 186                  * attempt allocation attempt fails, we'll end up cancelling
 187                  * a dirty transaction and shutting down.
 188                  *
 189                  * For an exact allocation, alignment must be 1,
 190                  * however we need to take cluster alignment into account when
 191                  * fixing up the freelist. Use the minalignslop field to
 192                  * indicate that extra blocks might be required for alignment,
 193                  * but not to use them in the actual exact allocation.
 194                  */
 195                 args.alignment = 1;
 196                 args.minalignslop = xfs_ialloc_cluster_alignment(&args) - 1;
 197
 198                 /* Allow space for the inode btree to split. */
 199                 args.minleft = XFS_IN_MAXLEVELS(args.mp) - 1;
 200                 if ((error = xfs_alloc_vextent(&args)))
 201                         return error;
 202         } else
 203                 args.fsbno = NULLFSBLOCK;
 204
 205         if (unlikely(args.fsbno == NULLFSBLOCK)) {
 206                 /*
 207                  * Set the alignment for the allocation.
 208                  * If stripe alignment is turned on then align at stripe unit
 209                  * boundary.
 210                  * If the cluster size is smaller than a filesystem block
 211                  * then we're doing I/O for inodes in filesystem block size
 212                  * pieces, so don't need alignment anyway.
 213                  */
 214                 isaligned = 0;
 215                 if (args.mp->m_sinoalign) {
 216                         ASSERT(!(args.mp->m_flags & XFS_MOUNT_NOALIGN));
 217                         args.alignment = args.mp->m_dalign;
 218                         isaligned = 1;
 219                 } else
 220                         args.alignment = xfs_ialloc_cluster_alignment(&args);
 221                 /*
 222                  * Need to figure out where to allocate the inode blocks.
 223                  * Ideally they should be spaced out through the a.g.
 224                  * For now, just allocate blocks up front.
 225                  */
 226                 args.agbno = be32_to_cpu(agi->agi_root);
 227                 args.fsbno = XFS_AGB_TO_FSB(args.mp,
 228                                 be32_to_cpu(agi->agi_seqno), args.agbno);
 229                 /*
 230                  * Allocate a fixed-size extent of inodes.
 231                  */
 232                 args.type = XFS_ALLOCTYPE_NEAR_BNO;
 233                 args.mod = args.total = args.wasdel = args.isfl =
 234                         args.userdata = args.minalignslop = 0;
 235                 args.prod = 1;
 236                 /*
 237                  * Allow space for the inode btree to split.
 238                  */
 239                 args.minleft = XFS_IN_MAXLEVELS(args.mp) - 1;
 240                 if ((error = xfs_alloc_vextent(&args)))
 241                         return error;
 242         }
 243
 244         /*
 245          * If stripe alignment is turned on, then try again with cluster
 246          * alignment.
 247          */
 248         if (isaligned && args.fsbno == NULLFSBLOCK) {
 249                 args.type = XFS_ALLOCTYPE_NEAR_BNO;
 250                 args.agbno = be32_to_cpu(agi->agi_root);
 251                 args.fsbno = XFS_AGB_TO_FSB(args.mp,
 252                                 be32_to_cpu(agi->agi_seqno), args.agbno);
 253                 args.alignment = xfs_ialloc_cluster_alignment(&args);
 254                 if ((error = xfs_alloc_vextent(&args)))
 255                         return error;
 256         }
 257
 258         if (args.fsbno == NULLFSBLOCK) {
 259                 *alloc = 0;
 260                 return 0;
 261         }
 262         ASSERT(args.len == args.minlen);
 263         /*
 264          * Convert the results.
 265          */
 266         newino = XFS_OFFBNO_TO_AGINO(args.mp, args.agbno, 0);
 267         /*
 268          * Loop over the new block(s), filling in the inodes.
 269          * For small block sizes, manipulate the inodes in buffers
 270          * which are multiples of the blocks size.
 271          */
 272         if (args.mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(args.mp)) {
 273                 blks_per_cluster = 1;
 274                 nbufs = (int)args.len;
 275                 ninodes = args.mp->m_sb.sb_inopblock;
 276         } else {
 277                 blks_per_cluster = XFS_INODE_CLUSTER_SIZE(args.mp) /
 278                                    args.mp->m_sb.sb_blocksize;
 279                 nbufs = (int)args.len / blks_per_cluster;
 280                 ninodes = blks_per_cluster * args.mp->m_sb.sb_inopblock;
 281         }
 282         /*
 283          * Figure out what version number to use in the inodes we create.
 284          * If the superblock version has caught up to the one that supports
 285          * the new inode format, then use the new inode version.  Otherwise
 286          * use the old version so that old kernels will continue to be
 287          * able to use the file system.
 288          */
 289         if (xfs_sb_version_hasnlink(&args.mp->m_sb))
 290                 version = XFS_DINODE_VERSION_2;
 291         else
 292                 version = XFS_DINODE_VERSION_1;
 293
 294         /*
 295          * Seed the new inode cluster with a random generation number. This
 296          * prevents short-term reuse of generation numbers if a chunk is
 297          * freed and then immediately reallocated. We use random numbers
 298          * rather than a linear progression to prevent the next generation
 299          * number from being easily guessable.
 300          */
 301         gen = random32();
 302         for (j = 0; j < nbufs; j++) {
 303                 /*
 304                  * Get the block.
 305                  */
 306                 d = XFS_AGB_TO_DADDR(args.mp, be32_to_cpu(agi->agi_seqno),
 307                                      args.agbno + (j * blks_per_cluster));
 308                 fbuf = xfs_trans_get_buf(tp, args.mp->m_ddev_targp, d,
 309                                          args.mp->m_bsize * blks_per_cluster,
 310                                          XFS_BUF_LOCK);
 311                 ASSERT(fbuf);
 312                 ASSERT(!XFS_BUF_GETERROR(fbuf));
 313                 /*
 314                  * Set initial values for the inodes in this buffer.
 315                  */
 316                 xfs_biozero(fbuf, 0, ninodes << args.mp->m_sb.sb_inodelog);
 317                 for (i = 0; i < ninodes; i++) {
 318                         free = XFS_MAKE_IPTR(args.mp, fbuf, i);
 319                         free->di_core.di_magic = cpu_to_be16(XFS_DINODE_MAGIC);
 320                         free->di_core.di_version = version;
 321                         free->di_core.di_gen = cpu_to_be32(gen);
 322                         free->di_next_unlinked = cpu_to_be32(NULLAGINO);
 323                         xfs_ialloc_log_di(tp, fbuf, i,
 324                                 XFS_DI_CORE_BITS | XFS_DI_NEXT_UNLINKED);
 325                 }
 326                 xfs_trans_inode_alloc_buf(tp, fbuf);
 327         }
 328         be32_add_cpu(&agi->agi_count, newlen);
 329         be32_add_cpu(&agi->agi_freecount, newlen);
 330         agno = be32_to_cpu(agi->agi_seqno);
 331         down_read(&args.mp->m_peraglock);
 332         args.mp->m_perag[agno].pagi_freecount += newlen;
 333         up_read(&args.mp->m_peraglock);
 334         agi->agi_newino = cpu_to_be32(newino);
 335         /*
 336          * Insert records describing the new inode chunk into the btree.
 337          */
 338         cur = xfs_btree_init_cursor(args.mp, tp, agbp, agno,
 339                         XFS_BTNUM_INO, (xfs_inode_t *)0, 0);
 340         for (thisino = newino;
 341              thisino < newino + newlen;
 342              thisino += XFS_INODES_PER_CHUNK) {
 343                 if ((error = xfs_inobt_lookup_eq(cur, thisino,
 344                                 XFS_INODES_PER_CHUNK, XFS_INOBT_ALL_FREE, &i))) {
 345                         xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
 346                         return error;
 347                 }
 348                 ASSERT(i == 0);
 349                 if ((error = xfs_inobt_insert(cur, &i))) {
 350                         xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
 351                         return error;
 352                 }
 353                 ASSERT(i == 1);
 354         }
 355         xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
 356         /*
 357          * Log allocation group header fields
 358          */
 359         xfs_ialloc_log_agi(tp, agbp,
 360                 XFS_AGI_COUNT | XFS_AGI_FREECOUNT | XFS_AGI_NEWINO);
 361         /*
 362          * Modify/log superblock values for inode count and inode free count.
 363          */
 364         xfs_trans_mod_sb(tp, XFS_TRANS_SB_ICOUNT, (long)newlen);
 365         xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, (long)newlen);
 366         *alloc = 1;
 367         return 0;
 368 }
 369
 370 STATIC_INLINE xfs_agnumber_t
 371 xfs_ialloc_next_ag(
 372         xfs_mount_t     *mp)
 373 {
 374         xfs_agnumber_t  agno;
 375
 376         spin_lock(&mp->m_agirotor_lock);
 377         agno = mp->m_agirotor;
 378         if (++mp->m_agirotor == mp->m_maxagi)
 379                 mp->m_agirotor = 0;
 380         spin_unlock(&mp->m_agirotor_lock);
 381
 382         return agno;
 383 }
 384
 385 /*
 386  * Select an allocation group to look for a free inode in, based on the parent
 387  * inode and then mode.  Return the allocation group buffer.
 388  */
 389 STATIC xfs_buf_t *                      /* allocation group buffer */
 390 xfs_ialloc_ag_select(
 391         xfs_trans_t     *tp,            /* transaction pointer */
 392         xfs_ino_t       parent,         /* parent directory inode number */
 393         mode_t          mode,           /* bits set to indicate file type */
 394         int             okalloc)        /* ok to allocate more space */
 395 {
 396         xfs_buf_t       *agbp;          /* allocation group header buffer */
 397         xfs_agnumber_t  agcount;        /* number of ag's in the filesystem */
 398         xfs_agnumber_t  agno;           /* current ag number */
 399         int             flags;          /* alloc buffer locking flags */
 400         xfs_extlen_t    ineed;          /* blocks needed for inode allocation */
 401         xfs_extlen_t    longest = 0;    /* longest extent available */
 402         xfs_mount_t     *mp;            /* mount point structure */
 403         int             needspace;      /* file mode implies space allocated */
 404         xfs_perag_t     *pag;           /* per allocation group data */
 405         xfs_agnumber_t  pagno;          /* parent (starting) ag number */
 406
 407         /*
 408          * Files of these types need at least one block if length > 0
 409          * (and they won't fit in the inode, but that's hard to figure out).
 410          */
 411         needspace = S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode);
 412         mp = tp->t_mountp;
 413         agcount = mp->m_maxagi;
 414         if (S_ISDIR(mode))
 415                 pagno = xfs_ialloc_next_ag(mp);
 416         else {
 417                 pagno = XFS_INO_TO_AGNO(mp, parent);
 418                 if (pagno >= agcount)
 419                         pagno = 0;
 420         }
 421         ASSERT(pagno < agcount);
 422         /*
 423          * Loop through allocation groups, looking for one with a little
 424          * free space in it.  Note we don't look for free inodes, exactly.
 425          * Instead, we include whether there is a need to allocate inodes
 426          * to mean that blocks must be allocated for them,
 427          * if none are currently free.
 428          */
 429         agno = pagno;
 430         flags = XFS_ALLOC_FLAG_TRYLOCK;
 431         down_read(&mp->m_peraglock);
 432         for (;;) {
 433                 pag = &mp->m_perag[agno];
 434                 if (!pag->pagi_init) {
 435                         if (xfs_ialloc_read_agi(mp, tp, agno, &agbp)) {
 436                                 agbp = NULL;
 437                                 goto nextag;
 438                         }
 439                 } else
 440                         agbp = NULL;
 441
 442                 if (!pag->pagi_inodeok) {
 443                         xfs_ialloc_next_ag(mp);
 444                         goto unlock_nextag;
 445                 }
 446
 447                 /*
 448                  * Is there enough free space for the file plus a block
 449                  * of inodes (if we need to allocate some)?
 450                  */
 451                 ineed = pag->pagi_freecount ? 0 : XFS_IALLOC_BLOCKS(mp);
 452                 if (ineed && !pag->pagf_init) {
 453                         if (agbp == NULL &&
 454                             xfs_ialloc_read_agi(mp, tp, agno, &agbp)) {
 455                                 agbp = NULL;
 456                                 goto nextag;
 457                         }
 458                         (void)xfs_alloc_pagf_init(mp, tp, agno, flags);
 459                 }
 460                 if (!ineed || pag->pagf_init) {
 461                         if (ineed && !(longest = pag->pagf_longest))
 462                                 longest = pag->pagf_flcount > 0;
 463                         if (!ineed ||
 464                             (pag->pagf_freeblks >= needspace + ineed &&
 465                              longest >= ineed &&
 466                              okalloc)) {
 467                                 if (agbp == NULL &&
 468                                     xfs_ialloc_read_agi(mp, tp, agno, &agbp)) {
 469                                         agbp = NULL;
 470                                         goto nextag;
 471                                 }
 472                                 up_read(&mp->m_peraglock);
 473                                 return agbp;
 474                         }
 475                 }
 476 unlock_nextag:
 477                 if (agbp)
 478                         xfs_trans_brelse(tp, agbp);
 479 nextag:
 480                 /*
 481                  * No point in iterating over the rest, if we're shutting
 482                  * down.
 483                  */
 484                 if (XFS_FORCED_SHUTDOWN(mp)) {
 485                         up_read(&mp->m_peraglock);
 486                         return NULL;
 487                 }
 488                 agno++;
 489                 if (agno >= agcount)
 490                         agno = 0;
 491                 if (agno == pagno) {
 492                         if (flags == 0) {
 493                                 up_read(&mp->m_peraglock);
 494                                 return NULL;
 495                         }
 496                         flags = 0;
 497                 }
 498         }
 499 }
 500
 501 /*
 502  * Visible inode allocation functions.
 503  */
 504
 505 /*
 506  * Allocate an inode on disk.
 507  * Mode is used to tell whether the new inode will need space, and whether
 508  * it is a directory.
 509  *
 510  * The arguments IO_agbp and alloc_done are defined to work within
 511  * the constraint of one allocation per transaction.
 512  * xfs_dialloc() is designed to be called twice if it has to do an
 513  * allocation to make more free inodes.  On the first call,
 514  * IO_agbp should be set to NULL. If an inode is available,
 515  * i.e., xfs_dialloc() did not need to do an allocation, an inode
 516  * number is returned.  In this case, IO_agbp would be set to the
 517  * current ag_buf and alloc_done set to false.
 518  * If an allocation needed to be done, xfs_dialloc would return
 519  * the current ag_buf in IO_agbp and set alloc_done to true.
 520  * The caller should then commit the current transaction, allocate a new
 521  * transaction, and call xfs_dialloc() again, passing in the previous
 522  * value of IO_agbp.  IO_agbp should be held across the transactions.
 523  * Since the agbp is locked across the two calls, the second call is
 524  * guaranteed to have a free inode available.
 525  *
 526  * Once we successfully pick an inode its number is returned and the
 527  * on-disk data structures are updated.  The inode itself is not read
 528  * in, since doing so would break ordering constraints with xfs_reclaim.
 529  */
 530 int
 531 xfs_dialloc(
 532         xfs_trans_t     *tp,            /* transaction pointer */
 533         xfs_ino_t       parent,         /* parent inode (directory) */
 534         mode_t          mode,           /* mode bits for new inode */
 535         int             okalloc,        /* ok to allocate more space */
 536         xfs_buf_t       **IO_agbp,      /* in/out ag header's buffer */
 537         boolean_t       *alloc_done,    /* true if we needed to replenish
 538                                            inode freelist */
 539         xfs_ino_t       *inop)          /* inode number allocated */
 540 {
 541         xfs_agnumber_t  agcount;        /* number of allocation groups */
 542         xfs_buf_t       *agbp;          /* allocation group header's buffer */
 543         xfs_agnumber_t  agno;           /* allocation group number */
 544         xfs_agi_t       *agi;           /* allocation group header structure */
 545         xfs_btree_cur_t *cur;           /* inode allocation btree cursor */
 546         int             error;          /* error return value */
 547         int             i;              /* result code */
 548         int             ialloced;       /* inode allocation status */
 549         int             noroom = 0;     /* no space for inode blk allocation */
 550         xfs_ino_t       ino;            /* fs-relative inode to be returned */
 551         /* REFERENCED */
 552         int             j;              /* result code */
 553         xfs_mount_t     *mp;            /* file system mount structure */
 554         int             offset;         /* index of inode in chunk */
 555         xfs_agino_t     pagino;         /* parent's a.g. relative inode # */
 556         xfs_agnumber_t  pagno;          /* parent's allocation group number */
 557         xfs_inobt_rec_incore_t rec;     /* inode allocation record */
 558         xfs_agnumber_t  tagno;          /* testing allocation group number */
 559         xfs_btree_cur_t *tcur;          /* temp cursor */
 560         xfs_inobt_rec_incore_t trec;    /* temp inode allocation record */
 561
 562
 563         if (*IO_agbp == NULL) {
 564                 /*
 565                  * We do not have an agbp, so select an initial allocation
 566                  * group for inode allocation.
 567                  */
 568                 agbp = xfs_ialloc_ag_select(tp, parent, mode, okalloc);
 569                 /*
 570                  * Couldn't find an allocation group satisfying the
 571                  * criteria, give up.
 572                  */
 573                 if (!agbp) {
 574                         *inop = NULLFSINO;
 575                         return 0;
 576                 }
 577                 agi = XFS_BUF_TO_AGI(agbp);
 578                 ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
 579         } else {
 580                 /*
 581                  * Continue where we left off before.  In this case, we
 582                  * know that the allocation group has free inodes.
 583                  */
 584                 agbp = *IO_agbp;
 585                 agi = XFS_BUF_TO_AGI(agbp);
 586                 ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
 587                 ASSERT(be32_to_cpu(agi->agi_freecount) > 0);
 588         }
 589         mp = tp->t_mountp;
 590         agcount = mp->m_sb.sb_agcount;
 591         agno = be32_to_cpu(agi->agi_seqno);
 592         tagno = agno;
 593         pagno = XFS_INO_TO_AGNO(mp, parent);
 594         pagino = XFS_INO_TO_AGINO(mp, parent);
 595
 596         /*
 597          * If we have already hit the ceiling of inode blocks then clear
 598          * okalloc so we scan all available agi structures for a free
 599          * inode.
 600          */
 601
 602         if (mp->m_maxicount &&
 603             mp->m_sb.sb_icount + XFS_IALLOC_INODES(mp) > mp->m_maxicount) {
 604                 noroom = 1;
 605                 okalloc = 0;
 606         }
 607
 608         /*
 609          * Loop until we find an allocation group that either has free inodes
 610          * or in which we can allocate some inodes.  Iterate through the
 611          * allocation groups upward, wrapping at the end.
 612          */
 613         *alloc_done = B_FALSE;
 614         while (!agi->agi_freecount) {
 615                 /*
 616                  * Don't do anything if we're not supposed to allocate
 617                  * any blocks, just go on to the next ag.
 618                  */
 619                 if (okalloc) {
 620                         /*
 621                          * Try to allocate some new inodes in the allocation
 622                          * group.
 623                          */
 624                         if ((error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced))) {
 625                                 xfs_trans_brelse(tp, agbp);
 626                                 if (error == ENOSPC) {
 627                                         *inop = NULLFSINO;
 628                                         return 0;
 629                                 } else
 630                                         return error;
 631                         }
 632                         if (ialloced) {
 633                                 /*
 634                                  * We successfully allocated some inodes, return
 635                                  * the current context to the caller so that it
 636                                  * can commit the current transaction and call
 637                                  * us again where we left off.
 638                                  */
 639                                 ASSERT(be32_to_cpu(agi->agi_freecount) > 0);
 640                                 *alloc_done = B_TRUE;
 641                                 *IO_agbp = agbp;
 642                                 *inop = NULLFSINO;
 643                                 return 0;
 644                         }
 645                 }
 646                 /*
 647                  * If it failed, give up on this ag.
 648                  */
 649                 xfs_trans_brelse(tp, agbp);
 650                 /*
 651                  * Go on to the next ag: get its ag header.
 652                  */
 653 nextag:
 654                 if (++tagno == agcount)
 655                         tagno = 0;
 656                 if (tagno == agno) {
 657                         *inop = NULLFSINO;
 658                         return noroom ? ENOSPC : 0;
 659                 }
 660                 down_read(&mp->m_peraglock);
 661                 if (mp->m_perag[tagno].pagi_inodeok == 0) {
 662                         up_read(&mp->m_peraglock);
 663                         goto nextag;
 664                 }
 665                 error = xfs_ialloc_read_agi(mp, tp, tagno, &agbp);
 666                 up_read(&mp->m_peraglock);
 667                 if (error)
 668                         goto nextag;
 669                 agi = XFS_BUF_TO_AGI(agbp);
 670                 ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
 671         }
 672         /*
 673          * Here with an allocation group that has a free inode.
 674          * Reset agno since we may have chosen a new ag in the
 675          * loop above.
 676          */
 677         agno = tagno;
 678         *IO_agbp = NULL;
 679         cur = xfs_btree_init_cursor(mp, tp, agbp, be32_to_cpu(agi->agi_seqno),
 680                                     XFS_BTNUM_INO, (xfs_inode_t *)0, 0);
 681         /*
 682          * If pagino is 0 (this is the root inode allocation) use newino.
 683          * This must work because we've just allocated some.
 684          */
 685         if (!pagino)
 686                 pagino = be32_to_cpu(agi->agi_newino);
 687 #ifdef DEBUG
 688         if (cur->bc_nlevels == 1) {
 689                 int     freecount = 0;
 690
 691                 if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
 692                         goto error0;
 693                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 694                 do {
 695                         if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino,
 696                                         &rec.ir_freecount, &rec.ir_free, &i)))
 697                                 goto error0;
 698                         XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 699                         freecount += rec.ir_freecount;
 700                         if ((error = xfs_inobt_increment(cur, 0, &i)))
 701                                 goto error0;
 702                 } while (i == 1);
 703
 704                 ASSERT(freecount == be32_to_cpu(agi->agi_freecount) ||
 705                        XFS_FORCED_SHUTDOWN(mp));
 706         }
 707 #endif
 708         /*
 709          * If in the same a.g. as the parent, try to get near the parent.
 710          */
 711         if (pagno == agno) {
 712                 if ((error = xfs_inobt_lookup_le(cur, pagino, 0, 0, &i)))
 713                         goto error0;
 714                 if (i != 0 &&
 715                     (error = xfs_inobt_get_rec(cur, &rec.ir_startino,
 716                             &rec.ir_freecount, &rec.ir_free, &j)) == 0 &&
 717                     j == 1 &&
 718                     rec.ir_freecount > 0) {
 719                         /*
 720                          * Found a free inode in the same chunk
 721                          * as parent, done.
 722                          */
 723                 }
 724                 /*
 725                  * In the same a.g. as parent, but parent's chunk is full.
 726                  */
 727                 else {
 728                         int     doneleft;       /* done, to the left */
 729                         int     doneright;      /* done, to the right */
 730
 731                         if (error)
 732                                 goto error0;
 733                         ASSERT(i == 1);
 734                         ASSERT(j == 1);
 735                         /*
 736                          * Duplicate the cursor, search left & right
 737                          * simultaneously.
 738                          */
 739                         if ((error = xfs_btree_dup_cursor(cur, &tcur)))
 740                                 goto error0;
 741                         /*
 742                          * Search left with tcur, back up 1 record.
 743                          */
 744                         if ((error = xfs_inobt_decrement(tcur, 0, &i)))
 745                                 goto error1;
 746                         doneleft = !i;
 747                         if (!doneleft) {
 748                                 if ((error = xfs_inobt_get_rec(tcur,
 749                                                 &trec.ir_startino,
 750                                                 &trec.ir_freecount,
 751                                                 &trec.ir_free, &i)))
 752                                         goto error1;
 753                                 XFS_WANT_CORRUPTED_GOTO(i == 1, error1);
 754                         }
 755                         /*
 756                          * Search right with cur, go forward 1 record.
 757                          */
 758                         if ((error = xfs_inobt_increment(cur, 0, &i)))
 759                                 goto error1;
 760                         doneright = !i;
 761                         if (!doneright) {
 762                                 if ((error = xfs_inobt_get_rec(cur,
 763                                                 &rec.ir_startino,
 764                                                 &rec.ir_freecount,
 765                                                 &rec.ir_free, &i)))
 766                                         goto error1;
 767                                 XFS_WANT_CORRUPTED_GOTO(i == 1, error1);
 768                         }
 769                         /*
 770                          * Loop until we find the closest inode chunk
 771                          * with a free one.
 772                          */
 773                         while (!doneleft || !doneright) {
 774                                 int     useleft;  /* using left inode
 775                                                      chunk this time */
 776
 777                                 /*
 778                                  * Figure out which block is closer,
 779                                  * if both are valid.
 780                                  */
 781                                 if (!doneleft && !doneright)
 782                                         useleft =
 783                                                 pagino -
 784                                                 (trec.ir_startino +
 785                                                  XFS_INODES_PER_CHUNK - 1) <
 786                                                  rec.ir_startino - pagino;
 787                                 else
 788                                         useleft = !doneleft;
 789                                 /*
 790                                  * If checking the left, does it have
 791                                  * free inodes?
 792                                  */
 793                                 if (useleft && trec.ir_freecount) {
 794                                         /*
 795                                          * Yes, set it up as the chunk to use.
 796                                          */
 797                                         rec = trec;
 798                                         xfs_btree_del_cursor(cur,
 799                                                 XFS_BTREE_NOERROR);
 800                                         cur = tcur;
 801                                         break;
 802                                 }
 803                                 /*
 804                                  * If checking the right, does it have
 805                                  * free inodes?
 806                                  */
 807                                 if (!useleft && rec.ir_freecount) {
 808                                         /*
 809                                          * Yes, it's already set up.
 810                                          */
 811                                         xfs_btree_del_cursor(tcur,
 812                                                 XFS_BTREE_NOERROR);
 813                                         break;
 814                                 }
 815                                 /*
 816                                  * If used the left, get another one
 817                                  * further left.
 818                                  */
 819                                 if (useleft) {
 820                                         if ((error = xfs_inobt_decrement(tcur, 0,
 821                                                         &i)))
 822                                                 goto error1;
 823                                         doneleft = !i;
 824                                         if (!doneleft) {
 825                                                 if ((error = xfs_inobt_get_rec(
 826                                                             tcur,
 827                                                             &trec.ir_startino,
 828                                                             &trec.ir_freecount,
 829                                                             &trec.ir_free, &i)))
 830                                                         goto error1;
 831                                                 XFS_WANT_CORRUPTED_GOTO(i == 1,
 832                                                         error1);
 833                                         }
 834                                 }
 835                                 /*
 836                                  * If used the right, get another one
 837                                  * further right.
 838                                  */
 839                                 else {
 840                                         if ((error = xfs_inobt_increment(cur, 0,
 841                                                         &i)))
 842                                                 goto error1;
 843                                         doneright = !i;
 844                                         if (!doneright) {
 845                                                 if ((error = xfs_inobt_get_rec(
 846                                                             cur,
 847                                                             &rec.ir_startino,
 848                                                             &rec.ir_freecount,
 849                                                             &rec.ir_free, &i)))
 850                                                         goto error1;
 851                                                 XFS_WANT_CORRUPTED_GOTO(i == 1,
 852                                                         error1);
 853                                         }
 854                                 }
 855                         }
 856                         ASSERT(!doneleft || !doneright);
 857                 }
 858         }
 859         /*
 860          * In a different a.g. from the parent.
 861          * See if the most recently allocated block has any free.
 862          */
 863         else if (be32_to_cpu(agi->agi_newino) != NULLAGINO) {
 864                 if ((error = xfs_inobt_lookup_eq(cur,
 865                                 be32_to_cpu(agi->agi_newino), 0, 0, &i)))
 866                         goto error0;
 867                 if (i == 1 &&
 868                     (error = xfs_inobt_get_rec(cur, &rec.ir_startino,
 869                             &rec.ir_freecount, &rec.ir_free, &j)) == 0 &&
 870                     j == 1 &&
 871                     rec.ir_freecount > 0) {
 872                         /*
 873                          * The last chunk allocated in the group still has
 874                          * a free inode.
 875                          */
 876                 }
 877                 /*
 878                  * None left in the last group, search the whole a.g.
 879                  */
 880                 else {
 881                         if (error)
 882                                 goto error0;
 883                         if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
 884                                 goto error0;
 885                         ASSERT(i == 1);
 886                         for (;;) {
 887                                 if ((error = xfs_inobt_get_rec(cur,
 888                                                 &rec.ir_startino,
 889                                                 &rec.ir_freecount, &rec.ir_free,
 890                                                 &i)))
 891                                         goto error0;
 892                                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 893                                 if (rec.ir_freecount > 0)
 894                                         break;
 895                                 if ((error = xfs_inobt_increment(cur, 0, &i)))
 896                                         goto error0;
 897                                 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 898                         }
 899                 }
 900         }
 901         offset = XFS_IALLOC_FIND_FREE(&rec.ir_free);
 902         ASSERT(offset >= 0);
 903         ASSERT(offset < XFS_INODES_PER_CHUNK);
 904         ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) %
 905                                    XFS_INODES_PER_CHUNK) == 0);
 906         ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset);
 907         XFS_INOBT_CLR_FREE(&rec, offset);
 908         rec.ir_freecount--;
 909         if ((error = xfs_inobt_update(cur, rec.ir_startino, rec.ir_freecount,
 910                         rec.ir_free)))
 911                 goto error0;
 912         be32_add_cpu(&agi->agi_freecount, -1);
 913         xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
 914         down_read(&mp->m_peraglock);
 915         mp->m_perag[tagno].pagi_freecount--;
 916         up_read(&mp->m_peraglock);
 917 #ifdef DEBUG
 918         if (cur->bc_nlevels == 1) {
 919                 int     freecount = 0;
 920
 921                 if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
 922                         goto error0;
 923                 do {
 924                         if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino,
 925                                         &rec.ir_freecount, &rec.ir_free, &i)))
 926                                 goto error0;
 927                         XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 928                         freecount += rec.ir_freecount;
 929                         if ((error = xfs_inobt_increment(cur, 0, &i)))
 930                                 goto error0;
 931                 } while (i == 1);
 932                 ASSERT(freecount == be32_to_cpu(agi->agi_freecount) ||
 933                        XFS_FORCED_SHUTDOWN(mp));
 934         }
 935 #endif
 936         xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
 937         xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1);
 938         *inop = ino;
 939         return 0;
 940 error1:
 941         xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
 942 error0:
 943         xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
 944         return error;
 945 }
 946
 947 /*
 948  * Free disk inode.  Carefully avoids touching the incore inode, all
 949  * manipulations incore are the caller's responsibility.
 950  * The on-disk inode is not changed by this operation, only the
 951  * btree (free inode mask) is changed.
 952  */
 953 int
 954 xfs_difree(
 955         xfs_trans_t     *tp,            /* transaction pointer */
 956         xfs_ino_t       inode,          /* inode to be freed */
 957         xfs_bmap_free_t *flist,         /* extents to free */
 958         int             *delete,        /* set if inode cluster was deleted */
 959         xfs_ino_t       *first_ino)     /* first inode in deleted cluster */
 960 {
 961         /* REFERENCED */
 962         xfs_agblock_t   agbno;  /* block number containing inode */
 963         xfs_buf_t       *agbp;  /* buffer containing allocation group header */
 964         xfs_agino_t     agino;  /* inode number relative to allocation group */
 965         xfs_agnumber_t  agno;   /* allocation group number */
 966         xfs_agi_t       *agi;   /* allocation group header */
 967         xfs_btree_cur_t *cur;   /* inode btree cursor */
 968         int             error;  /* error return value */
 969         int             i;      /* result code */
 970         int             ilen;   /* inodes in an inode cluster */
 971         xfs_mount_t     *mp;    /* mount structure for filesystem */
 972         int             off;    /* offset of inode in inode chunk */
 973         xfs_inobt_rec_incore_t rec;     /* btree record */
 974
 975         mp = tp->t_mountp;
 976
 977         /*
 978          * Break up inode number into its components.
 979          */
 980         agno = XFS_INO_TO_AGNO(mp, inode);
 981         if (agno >= mp->m_sb.sb_agcount)  {
 982                 cmn_err(CE_WARN,
 983                         "xfs_difree: agno >= mp->m_sb.sb_agcount (%d >= %d) on %s.  Returning EINVAL.",
 984                         agno, mp->m_sb.sb_agcount, mp->m_fsname);
 985                 ASSERT(0);
 986                 return XFS_ERROR(EINVAL);
 987         }
 988         agino = XFS_INO_TO_AGINO(mp, inode);
 989         if (inode != XFS_AGINO_TO_INO(mp, agno, agino))  {
 990                 cmn_err(CE_WARN,
 991                         "xfs_difree: inode != XFS_AGINO_TO_INO() "
 992                         "(%llu != %llu) on %s.  Returning EINVAL.",
 993                         (unsigned long long)inode,
 994                         (unsigned long long)XFS_AGINO_TO_INO(mp, agno, agino),
 995                         mp->m_fsname);
 996                 ASSERT(0);
 997                 return XFS_ERROR(EINVAL);
 998         }
 999         agbno = XFS_AGINO_TO_AGBNO(mp, agino);
1000         if (agbno >= mp->m_sb.sb_agblocks)  {
1001                 cmn_err(CE_WARN,
1002                         "xfs_difree: agbno >= mp->m_sb.sb_agblocks (%d >= %d) on %s.  Returning EINVAL.",
1003                         agbno, mp->m_sb.sb_agblocks, mp->m_fsname);
1004                 ASSERT(0);
1005                 return XFS_ERROR(EINVAL);
1006         }
1007         /*
1008          * Get the allocation group header.
1009          */
1010         down_read(&mp->m_peraglock);
1011         error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
1012         up_read(&mp->m_peraglock);
1013         if (error) {
1014                 cmn_err(CE_WARN,
1015                         "xfs_difree: xfs_ialloc_read_agi() returned an error %d on %s.  Returning error.",
1016                         error, mp->m_fsname);
1017                 return error;
1018         }
1019         agi = XFS_BUF_TO_AGI(agbp);
1020         ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
1021         ASSERT(agbno < be32_to_cpu(agi->agi_length));
1022         /*
1023          * Initialize the cursor.
1024          */
1025         cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO,
1026                 (xfs_inode_t *)0, 0);
1027 #ifdef DEBUG
1028         if (cur->bc_nlevels == 1) {
1029                 int freecount = 0;
1030
1031                 if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
1032                         goto error0;
1033                 do {
1034                         if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino,
1035                                         &rec.ir_freecount, &rec.ir_free, &i)))
1036                                 goto error0;
1037                         if (i) {
1038                                 freecount += rec.ir_freecount;
1039                                 if ((error = xfs_inobt_increment(cur, 0, &i)))
1040                                         goto error0;
1041                         }
1042                 } while (i == 1);
1043                 ASSERT(freecount == be32_to_cpu(agi->agi_freecount) ||
1044                        XFS_FORCED_SHUTDOWN(mp));
1045         }
1046 #endif
1047         /*
1048          * Look for the entry describing this inode.
1049          */
1050         if ((error = xfs_inobt_lookup_le(cur, agino, 0, 0, &i))) {
1051                 cmn_err(CE_WARN,
1052                         "xfs_difree: xfs_inobt_lookup_le returned()  an error %d on %s.  Returning error.",
1053                         error, mp->m_fsname);
1054                 goto error0;
1055         }
1056         XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1057         if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino, &rec.ir_freecount,
1058                         &rec.ir_free, &i))) {
1059                 cmn_err(CE_WARN,
1060                         "xfs_difree: xfs_inobt_get_rec()  returned an error %d on %s.  Returning error.",
1061                         error, mp->m_fsname);
1062                 goto error0;
1063         }
1064         XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1065         /*
1066          * Get the offset in the inode chunk.
1067          */
1068         off = agino - rec.ir_startino;
1069         ASSERT(off >= 0 && off < XFS_INODES_PER_CHUNK);
1070         ASSERT(!XFS_INOBT_IS_FREE(&rec, off));
1071         /*
1072          * Mark the inode free & increment the count.
1073          */
1074         XFS_INOBT_SET_FREE(&rec, off);
1075         rec.ir_freecount++;
1076
1077         /*
1078          * When an inode cluster is free, it becomes eligible for removal
1079          */
1080         if (!(mp->m_flags & XFS_MOUNT_IKEEP) &&
1081             (rec.ir_freecount == XFS_IALLOC_INODES(mp))) {
1082
1083                 *delete = 1;
1084                 *first_ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino);
1085
1086                 /*
1087                  * Remove the inode cluster from the AGI B+Tree, adjust the
1088                  * AGI and Superblock inode counts, and mark the disk space
1089                  * to be freed when the transaction is committed.
1090                  */
1091                 ilen = XFS_IALLOC_INODES(mp);
1092                 be32_add_cpu(&agi->agi_count, -ilen);
1093                 be32_add_cpu(&agi->agi_freecount, -(ilen - 1));
1094                 xfs_ialloc_log_agi(tp, agbp, XFS_AGI_COUNT | XFS_AGI_FREECOUNT);
1095                 down_read(&mp->m_peraglock);
1096                 mp->m_perag[agno].pagi_freecount -= ilen - 1;
1097                 up_read(&mp->m_peraglock);
1098                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_ICOUNT, -ilen);
1099                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -(ilen - 1));
1100
1101                 if ((error = xfs_inobt_delete(cur, &i))) {
1102                         cmn_err(CE_WARN, "xfs_difree: xfs_inobt_delete returned an error %d on %s.\n",
1103                                 error, mp->m_fsname);
1104                         goto error0;
1105                 }
1106
1107                 xfs_bmap_add_free(XFS_AGB_TO_FSB(mp,
1108                                 agno, XFS_INO_TO_AGBNO(mp,rec.ir_startino)),
1109                                 XFS_IALLOC_BLOCKS(mp), flist, mp);
1110         } else {
1111                 *delete = 0;
1112
1113                 if ((error = xfs_inobt_update(cur, rec.ir_startino, rec.ir_freecount, rec.ir_free))) {
1114                         cmn_err(CE_WARN,
1115                                 "xfs_difree: xfs_inobt_update()  returned an error %d on %s.  Returning error.",
1116                                 error, mp->m_fsname);
1117                         goto error0;
1118                 }
1119                 /*
1120                  * Change the inode free counts and log the ag/sb changes.
1121                  */
1122                 be32_add_cpu(&agi->agi_freecount, 1);
1123                 xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
1124                 down_read(&mp->m_peraglock);
1125                 mp->m_perag[agno].pagi_freecount++;
1126                 up_read(&mp->m_peraglock);
1127                 xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, 1);
1128         }
1129
1130 #ifdef DEBUG
1131         if (cur->bc_nlevels == 1) {
1132                 int freecount = 0;
1133
1134                 if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
1135                         goto error0;
1136                 do {
1137                         if ((error = xfs_inobt_get_rec(cur,
1138                                         &rec.ir_startino,
1139                                         &rec.ir_freecount,
1140                                         &rec.ir_free, &i)))
1141                                 goto error0;
1142                         if (i) {
1143                                 freecount += rec.ir_freecount;
1144                                 if ((error = xfs_inobt_increment(cur, 0, &i)))
1145                                         goto error0;
1146                         }
1147                 } while (i == 1);
1148                 ASSERT(freecount == be32_to_cpu(agi->agi_freecount) ||
1149                        XFS_FORCED_SHUTDOWN(mp));
1150         }
1151 #endif
1152         xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
1153         return 0;
1154
1155 error0:
1156         xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
1157         return error;
1158 }
1159
1160 /*
1161  * Return the location of the inode in bno/off, for mapping it into a buffer.
1162  */
1163 /*ARGSUSED*/
1164 int
1165 xfs_dilocate(
1166         xfs_mount_t     *mp,    /* file system mount structure */
1167         xfs_trans_t     *tp,    /* transaction pointer */
1168         xfs_ino_t       ino,    /* inode to locate */
1169         xfs_fsblock_t   *bno,   /* output: block containing inode */
1170         int             *len,   /* output: num blocks in inode cluster */
1171         int             *off,   /* output: index in block of inode */
1172         uint            flags)  /* flags concerning inode lookup */
1173 {
1174         xfs_agblock_t   agbno;  /* block number of inode in the alloc group */
1175         xfs_buf_t       *agbp;  /* agi buffer */
1176         xfs_agino_t     agino;  /* inode number within alloc group */
1177         xfs_agnumber_t  agno;   /* allocation group number */
1178         int             blks_per_cluster; /* num blocks per inode cluster */
1179         xfs_agblock_t   chunk_agbno;    /* first block in inode chunk */
1180         xfs_agino_t     chunk_agino;    /* first agino in inode chunk */
1181         __int32_t       chunk_cnt;      /* count of free inodes in chunk */
1182         xfs_inofree_t   chunk_free;     /* mask of free inodes in chunk */
1183         xfs_agblock_t   cluster_agbno;  /* first block in inode cluster */
1184         xfs_btree_cur_t *cur;   /* inode btree cursor */
1185         int             error;  /* error code */
1186         int             i;      /* temp state */
1187         int             offset; /* index of inode in its buffer */
1188         int             offset_agbno;   /* blks from chunk start to inode */
1189
1190         ASSERT(ino != NULLFSINO);
1191         /*
1192          * Split up the inode number into its parts.
1193          */
1194         agno = XFS_INO_TO_AGNO(mp, ino);
1195         agino = XFS_INO_TO_AGINO(mp, ino);
1196         agbno = XFS_AGINO_TO_AGBNO(mp, agino);
1197         if (agno >= mp->m_sb.sb_agcount || agbno >= mp->m_sb.sb_agblocks ||
1198             ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
1199 #ifdef DEBUG
1200                 /* no diagnostics for bulkstat, ino comes from userspace */
1201                 if (flags & XFS_IMAP_BULKSTAT)
1202                         return XFS_ERROR(EINVAL);
1203                 if (agno >= mp->m_sb.sb_agcount) {
1204                         xfs_fs_cmn_err(CE_ALERT, mp,
1205                                         "xfs_dilocate: agno (%d) >= "
1206                                         "mp->m_sb.sb_agcount (%d)",
1207                                         agno,  mp->m_sb.sb_agcount);
1208                 }
1209                 if (agbno >= mp->m_sb.sb_agblocks) {
1210                         xfs_fs_cmn_err(CE_ALERT, mp,
1211                                         "xfs_dilocate: agbno (0x%llx) >= "
1212                                         "mp->m_sb.sb_agblocks (0x%lx)",
1213                                         (unsigned long long) agbno,
1214                                         (unsigned long) mp->m_sb.sb_agblocks);
1215                 }
1216                 if (ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
1217                         xfs_fs_cmn_err(CE_ALERT, mp,
1218                                         "xfs_dilocate: ino (0x%llx) != "
1219                                         "XFS_AGINO_TO_INO(mp, agno, agino) "
1220                                         "(0x%llx)",
1221                                         ino, XFS_AGINO_TO_INO(mp, agno, agino));
1222                 }
1223                 xfs_stack_trace();
1224 #endif /* DEBUG */
1225                 return XFS_ERROR(EINVAL);
1226         }
1227         if ((mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(mp)) ||
1228             !(flags & XFS_IMAP_LOOKUP)) {
1229                 offset = XFS_INO_TO_OFFSET(mp, ino);
1230                 ASSERT(offset < mp->m_sb.sb_inopblock);
1231                 *bno = XFS_AGB_TO_FSB(mp, agno, agbno);
1232                 *off = offset;
1233                 *len = 1;
1234                 return 0;
1235         }
1236         blks_per_cluster = XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_blocklog;
1237         if (*bno != NULLFSBLOCK) {
1238                 offset = XFS_INO_TO_OFFSET(mp, ino);
1239                 ASSERT(offset < mp->m_sb.sb_inopblock);
1240                 cluster_agbno = XFS_FSB_TO_AGBNO(mp, *bno);
1241                 *off = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
1242                         offset;
1243                 *len = blks_per_cluster;
1244                 return 0;
1245         }
1246         if (mp->m_inoalign_mask) {
1247                 offset_agbno = agbno & mp->m_inoalign_mask;
1248                 chunk_agbno = agbno - offset_agbno;
1249         } else {
1250                 down_read(&mp->m_peraglock);
1251                 error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
1252                 up_read(&mp->m_peraglock);
1253                 if (error) {
1254 #ifdef DEBUG
1255                         xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
1256                                         "xfs_ialloc_read_agi() returned "
1257                                         "error %d, agno %d",
1258                                         error, agno);
1259 #endif /* DEBUG */
1260                         return error;
1261                 }
1262                 cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO,
1263                         (xfs_inode_t *)0, 0);
1264                 if ((error = xfs_inobt_lookup_le(cur, agino, 0, 0, &i))) {
1265 #ifdef DEBUG
1266                         xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
1267                                         "xfs_inobt_lookup_le() failed");
1268 #endif /* DEBUG */
1269                         goto error0;
1270                 }
1271                 if ((error = xfs_inobt_get_rec(cur, &chunk_agino, &chunk_cnt,
1272                                 &chunk_free, &i))) {
1273 #ifdef DEBUG
1274                         xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
1275                                         "xfs_inobt_get_rec() failed");
1276 #endif /* DEBUG */
1277                         goto error0;
1278                 }
1279                 if (i == 0) {
1280 #ifdef DEBUG
1281                         xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
1282                                         "xfs_inobt_get_rec() failed");
1283 #endif /* DEBUG */
1284                         error = XFS_ERROR(EINVAL);
1285                 }
1286                 xfs_trans_brelse(tp, agbp);
1287                 xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
1288                 if (error)
1289                         return error;
1290                 chunk_agbno = XFS_AGINO_TO_AGBNO(mp, chunk_agino);
1291                 offset_agbno = agbno - chunk_agbno;
1292         }
1293         ASSERT(agbno >= chunk_agbno);
1294         cluster_agbno = chunk_agbno +
1295                 ((offset_agbno / blks_per_cluster) * blks_per_cluster);
1296         offset = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
1297                 XFS_INO_TO_OFFSET(mp, ino);
1298         *bno = XFS_AGB_TO_FSB(mp, agno, cluster_agbno);
1299         *off = offset;
1300         *len = blks_per_cluster;
1301         return 0;
1302 error0:
1303         xfs_trans_brelse(tp, agbp);
1304         xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
1305         return error;
1306 }
1307
1308 /*
1309  * Compute and fill in value of m_in_maxlevels.
1310  */
1311 void
1312 xfs_ialloc_compute_maxlevels(
1313         xfs_mount_t     *mp)            /* file system mount structure */
1314 {
1315         int             level;
1316         uint            maxblocks;
1317         uint            maxleafents;
1318         int             minleafrecs;
1319         int             minnoderecs;
1320
1321         maxleafents = (1LL << XFS_INO_AGINO_BITS(mp)) >>
1322                 XFS_INODES_PER_CHUNK_LOG;
1323         minleafrecs = mp->m_alloc_mnr[0];
1324         minnoderecs = mp->m_alloc_mnr[1];
1325         maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1326         for (level = 1; maxblocks > 1; level++)
1327                 maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1328         mp->m_in_maxlevels = level;
1329 }
1330
1331 /*
1332  * Log specified fields for the ag hdr (inode section)
1333  */
1334 void
1335 xfs_ialloc_log_agi(
1336         xfs_trans_t     *tp,            /* transaction pointer */
1337         xfs_buf_t       *bp,            /* allocation group header buffer */
1338         int             fields)         /* bitmask of fields to log */
1339 {
1340         int                     first;          /* first byte number */
1341         int                     last;           /* last byte number */
1342         static const short      offsets[] = {   /* field starting offsets */
1343                                         /* keep in sync with bit definitions */
1344                 offsetof(xfs_agi_t, agi_magicnum),
1345                 offsetof(xfs_agi_t, agi_versionnum),
1346                 offsetof(xfs_agi_t, agi_seqno),
1347                 offsetof(xfs_agi_t, agi_length),
1348                 offsetof(xfs_agi_t, agi_count),
1349                 offsetof(xfs_agi_t, agi_root),
1350                 offsetof(xfs_agi_t, agi_level),
1351                 offsetof(xfs_agi_t, agi_freecount),
1352                 offsetof(xfs_agi_t, agi_newino),
1353                 offsetof(xfs_agi_t, agi_dirino),
1354                 offsetof(xfs_agi_t, agi_unlinked),
1355                 sizeof(xfs_agi_t)
1356         };
1357 #ifdef DEBUG
1358         xfs_agi_t               *agi;   /* allocation group header */
1359
1360         agi = XFS_BUF_TO_AGI(bp);
1361         ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
1362 #endif
1363         /*
1364          * Compute byte offsets for the first and last fields.
1365          */
1366         xfs_btree_offsets(fields, offsets, XFS_AGI_NUM_BITS, &first, &last);
1367         /*
1368          * Log the allocation group inode header buffer.
1369          */
1370         xfs_trans_log_buf(tp, bp, first, last);
1371 }
1372
1373 /*
1374  * Read in the allocation group header (inode allocation section)
1375  */
1376 int
1377 xfs_ialloc_read_agi(
1378         xfs_mount_t     *mp,            /* file system mount structure */
1379         xfs_trans_t     *tp,            /* transaction pointer */
1380         xfs_agnumber_t  agno,           /* allocation group number */
1381         xfs_buf_t       **bpp)          /* allocation group hdr buf */
1382 {
1383         xfs_agi_t       *agi;           /* allocation group header */
1384         int             agi_ok;         /* agi is consistent */
1385         xfs_buf_t       *bp;            /* allocation group hdr buf */
1386         xfs_perag_t     *pag;           /* per allocation group data */
1387         int             error;
1388
1389         ASSERT(agno != NULLAGNUMBER);
1390         error = xfs_trans_read_buf(
1391                         mp, tp, mp->m_ddev_targp,
1392                         XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
1393                         XFS_FSS_TO_BB(mp, 1), 0, &bp);
1394         if (error)
1395                 return error;
1396         ASSERT(bp && !XFS_BUF_GETERROR(bp));
1397
1398         /*
1399          * Validate the magic number of the agi block.
1400          */
1401         agi = XFS_BUF_TO_AGI(bp);
1402         agi_ok =
1403                 be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC &&
1404                 XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum));
1405         if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IALLOC_READ_AGI,
1406                         XFS_RANDOM_IALLOC_READ_AGI))) {
1407                 XFS_CORRUPTION_ERROR("xfs_ialloc_read_agi", XFS_ERRLEVEL_LOW,
1408                                      mp, agi);
1409                 xfs_trans_brelse(tp, bp);
1410                 return XFS_ERROR(EFSCORRUPTED);
1411         }
1412         pag = &mp->m_perag[agno];
1413         if (!pag->pagi_init) {
1414                 pag->pagi_freecount = be32_to_cpu(agi->agi_freecount);
1415                 pag->pagi_count = be32_to_cpu(agi->agi_count);
1416                 pag->pagi_init = 1;
1417         } else {
1418                 /*
1419                  * It's possible for these to be out of sync if
1420                  * we are in the middle of a forced shutdown.
1421                  */
1422                 ASSERT(pag->pagi_freecount == be32_to_cpu(agi->agi_freecount) ||
1423                         XFS_FORCED_SHUTDOWN(mp));
1424         }
1425
1426 #ifdef DEBUG
1427         {
1428                 int     i;
1429
1430                 for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)
1431                         ASSERT(agi->agi_unlinked[i]);
1432         }
1433 #endif
1434
1435         XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGI, XFS_AGI_REF);
1436         *bpp = bp;
1437         return 0;
1438 }
1439
1440 /*
1441  * Read in the agi to initialise the per-ag data in the mount structure
1442  */
1443 int
1444 xfs_ialloc_pagi_init(
1445         xfs_mount_t     *mp,            /* file system mount structure */
1446         xfs_trans_t     *tp,            /* transaction pointer */
1447         xfs_agnumber_t  agno)           /* allocation group number */
1448 {
1449         xfs_buf_t       *bp = NULL;
1450         int             error;
1451
1452         error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
1453         if (error)
1454                 return error;
1455         if (bp)
1456                 xfs_trans_brelse(tp, bp);
1457         return 0;
1458 }