fs/xfs/xfs_itable.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_log.h"
  22 #include "xfs_inum.h"
  23 #include "xfs_trans.h"
  24 #include "xfs_sb.h"
  25 #include "xfs_ag.h"
  26 #include "xfs_mount.h"
  27 #include "xfs_bmap_btree.h"
  28 #include "xfs_alloc_btree.h"
  29 #include "xfs_ialloc_btree.h"
  30 #include "xfs_dinode.h"
  31 #include "xfs_inode.h"
  32 #include "xfs_ialloc.h"
  33 #include "xfs_itable.h"
  34 #include "xfs_error.h"
  35 #include "xfs_btree.h"
  36 #include "xfs_trace.h"
  37 #include "xfs_icache.h"
  38
  39 STATIC int
  40 xfs_internal_inum(
  41         xfs_mount_t     *mp,
  42         xfs_ino_t       ino)
  43 {
  44         return (ino == mp->m_sb.sb_rbmino || ino == mp->m_sb.sb_rsumino ||
  45                 (xfs_sb_version_hasquota(&mp->m_sb) &&
  46                  xfs_is_quota_inode(&mp->m_sb, ino)));
  47 }
  48
  49 /*
  50  * Return stat information for one inode.
  51  * Return 0 if ok, else errno.
  52  */
  53 int
  54 xfs_bulkstat_one_int(
  55         struct xfs_mount        *mp,            /* mount point for filesystem */
  56         xfs_ino_t               ino,            /* inode to get data for */
  57         void __user             *buffer,        /* buffer to place output in */
  58         int                     ubsize,         /* size of buffer */
  59         bulkstat_one_fmt_pf     formatter,      /* formatter, copy to user */
  60         int                     *ubused,        /* bytes used by me */
  61         int                     *stat)          /* BULKSTAT_RV_... */
  62 {
  63         struct xfs_icdinode     *dic;           /* dinode core info pointer */
  64         struct xfs_inode        *ip;            /* incore inode pointer */
  65         struct xfs_bstat        *buf;           /* return buffer */
  66         int                     error = 0;      /* error value */
  67
  68         *stat = BULKSTAT_RV_NOTHING;
  69
  70         if (!buffer || xfs_internal_inum(mp, ino))
  71                 return XFS_ERROR(EINVAL);
  72
  73         buf = kmem_alloc(sizeof(*buf), KM_SLEEP | KM_MAYFAIL);
  74         if (!buf)
  75                 return XFS_ERROR(ENOMEM);
  76
  77         error = xfs_iget(mp, NULL, ino,
  78                          (XFS_IGET_DONTCACHE | XFS_IGET_UNTRUSTED),
  79                          XFS_ILOCK_SHARED, &ip);
  80         if (error) {
  81                 *stat = BULKSTAT_RV_NOTHING;
  82                 goto out_free;
  83         }
  84
  85         ASSERT(ip != NULL);
  86         ASSERT(ip->i_imap.im_blkno != 0);
  87
  88         dic = &ip->i_d;
  89
  90         /* xfs_iget returns the following without needing
  91          * further change.
  92          */
  93         buf->bs_nlink = dic->di_nlink;
  94         buf->bs_projid_lo = dic->di_projid_lo;
  95         buf->bs_projid_hi = dic->di_projid_hi;
  96         buf->bs_ino = ino;
  97         buf->bs_mode = dic->di_mode;
  98         buf->bs_uid = dic->di_uid;
  99         buf->bs_gid = dic->di_gid;
 100         buf->bs_size = dic->di_size;
 101         buf->bs_atime.tv_sec = dic->di_atime.t_sec;
 102         buf->bs_atime.tv_nsec = dic->di_atime.t_nsec;
 103         buf->bs_mtime.tv_sec = dic->di_mtime.t_sec;
 104         buf->bs_mtime.tv_nsec = dic->di_mtime.t_nsec;
 105         buf->bs_ctime.tv_sec = dic->di_ctime.t_sec;
 106         buf->bs_ctime.tv_nsec = dic->di_ctime.t_nsec;
 107         buf->bs_xflags = xfs_ip2xflags(ip);
 108         buf->bs_extsize = dic->di_extsize << mp->m_sb.sb_blocklog;
 109         buf->bs_extents = dic->di_nextents;
 110         buf->bs_gen = dic->di_gen;
 111         memset(buf->bs_pad, 0, sizeof(buf->bs_pad));
 112         buf->bs_dmevmask = dic->di_dmevmask;
 113         buf->bs_dmstate = dic->di_dmstate;
 114         buf->bs_aextents = dic->di_anextents;
 115         buf->bs_forkoff = XFS_IFORK_BOFF(ip);
 116
 117         switch (dic->di_format) {
 118         case XFS_DINODE_FMT_DEV:
 119                 buf->bs_rdev = ip->i_df.if_u2.if_rdev;
 120                 buf->bs_blksize = BLKDEV_IOSIZE;
 121                 buf->bs_blocks = 0;
 122                 break;
 123         case XFS_DINODE_FMT_LOCAL:
 124         case XFS_DINODE_FMT_UUID:
 125                 buf->bs_rdev = 0;
 126                 buf->bs_blksize = mp->m_sb.sb_blocksize;
 127                 buf->bs_blocks = 0;
 128                 break;
 129         case XFS_DINODE_FMT_EXTENTS:
 130         case XFS_DINODE_FMT_BTREE:
 131                 buf->bs_rdev = 0;
 132                 buf->bs_blksize = mp->m_sb.sb_blocksize;
 133                 buf->bs_blocks = dic->di_nblocks + ip->i_delayed_blks;
 134                 break;
 135         }
 136         xfs_iunlock(ip, XFS_ILOCK_SHARED);
 137         IRELE(ip);
 138
 139         error = formatter(buffer, ubsize, ubused, buf);
 140
 141         if (!error)
 142                 *stat = BULKSTAT_RV_DIDONE;
 143
 144  out_free:
 145         kmem_free(buf);
 146         return error;
 147 }
 148
 149 /* Return 0 on success or positive error */
 150 STATIC int
 151 xfs_bulkstat_one_fmt(
 152         void                    __user *ubuffer,
 153         int                     ubsize,
 154         int                     *ubused,
 155         const xfs_bstat_t       *buffer)
 156 {
 157         if (ubsize < sizeof(*buffer))
 158                 return XFS_ERROR(ENOMEM);
 159         if (copy_to_user(ubuffer, buffer, sizeof(*buffer)))
 160                 return XFS_ERROR(EFAULT);
 161         if (ubused)
 162                 *ubused = sizeof(*buffer);
 163         return 0;
 164 }
 165
 166 int
 167 xfs_bulkstat_one(
 168         xfs_mount_t     *mp,            /* mount point for filesystem */
 169         xfs_ino_t       ino,            /* inode number to get data for */
 170         void            __user *buffer, /* buffer to place output in */
 171         int             ubsize,         /* size of buffer */
 172         int             *ubused,        /* bytes used by me */
 173         int             *stat)          /* BULKSTAT_RV_... */
 174 {
 175         return xfs_bulkstat_one_int(mp, ino, buffer, ubsize,
 176                                     xfs_bulkstat_one_fmt, ubused, stat);
 177 }
 178
 179 #define XFS_BULKSTAT_UBLEFT(ubleft)     ((ubleft) >= statstruct_size)
 180
 181 /*
 182  * Return stat information in bulk (by-inode) for the filesystem.
 183  */
 184 int                                     /* error status */
 185 xfs_bulkstat(
 186         xfs_mount_t             *mp,    /* mount point for filesystem */
 187         xfs_ino_t               *lastinop, /* last inode returned */
 188         int                     *ubcountp, /* size of buffer/count returned */
 189         bulkstat_one_pf         formatter, /* func that'd fill a single buf */
 190         size_t                  statstruct_size, /* sizeof struct filling */
 191         char                    __user *ubuffer, /* buffer with inode stats */
 192         int                     *done)  /* 1 if there are more stats to get */
 193 {
 194         xfs_agblock_t           agbno=0;/* allocation group block number */
 195         xfs_buf_t               *agbp;  /* agi header buffer */
 196         xfs_agi_t               *agi;   /* agi header data */
 197         xfs_agino_t             agino;  /* inode # in allocation group */
 198         xfs_agnumber_t          agno;   /* allocation group number */
 199         int                     chunkidx; /* current index into inode chunk */
 200         int                     clustidx; /* current index into inode cluster */
 201         xfs_btree_cur_t         *cur;   /* btree cursor for ialloc btree */
 202         int                     end_of_ag; /* set if we've seen the ag end */
 203         int                     error;  /* error code */
 204         int                     fmterror;/* bulkstat formatter result */
 205         int                     i;      /* loop index */
 206         int                     icount; /* count of inodes good in irbuf */
 207         size_t                  irbsize; /* size of irec buffer in bytes */
 208         xfs_ino_t               ino;    /* inode number (filesystem) */
 209         xfs_inobt_rec_incore_t  *irbp;  /* current irec buffer pointer */
 210         xfs_inobt_rec_incore_t  *irbuf; /* start of irec buffer */
 211         xfs_inobt_rec_incore_t  *irbufend; /* end of good irec buffer entries */
 212         xfs_ino_t               lastino; /* last inode number returned */
 213         int                     nbcluster; /* # of blocks in a cluster */
 214         int                     nicluster; /* # of inodes in a cluster */
 215         int                     nimask; /* mask for inode clusters */
 216         int                     nirbuf; /* size of irbuf */
 217         int                     rval;   /* return value error code */
 218         int                     tmp;    /* result value from btree calls */
 219         int                     ubcount; /* size of user's buffer */
 220         int                     ubleft; /* bytes left in user's buffer */
 221         char                    __user *ubufp;  /* pointer into user's buffer */
 222         int                     ubelem; /* spaces used in user's buffer */
 223         int                     ubused; /* bytes used by formatter */
 224
 225         /*
 226          * Get the last inode value, see if there's nothing to do.
 227          */
 228         ino = (xfs_ino_t)*lastinop;
 229         lastino = ino;
 230         agno = XFS_INO_TO_AGNO(mp, ino);
 231         agino = XFS_INO_TO_AGINO(mp, ino);
 232         if (agno >= mp->m_sb.sb_agcount ||
 233             ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
 234                 *done = 1;
 235                 *ubcountp = 0;
 236                 return 0;
 237         }
 238         if (!ubcountp || *ubcountp <= 0) {
 239                 return EINVAL;
 240         }
 241         ubcount = *ubcountp; /* statstruct's */
 242         ubleft = ubcount * statstruct_size; /* bytes */
 243         *ubcountp = ubelem = 0;
 244         *done = 0;
 245         fmterror = 0;
 246         ubufp = ubuffer;
 247         nicluster = mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(mp) ?
 248                 mp->m_sb.sb_inopblock :
 249                 (XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog);
 250         nimask = ~(nicluster - 1);
 251         nbcluster = nicluster >> mp->m_sb.sb_inopblog;
 252         irbuf = kmem_zalloc_greedy(&irbsize, PAGE_SIZE, PAGE_SIZE * 4);
 253         if (!irbuf)
 254                 return ENOMEM;
 255
 256         nirbuf = irbsize / sizeof(*irbuf);
 257
 258         /*
 259          * Loop over the allocation groups, starting from the last
 260          * inode returned; 0 means start of the allocation group.
 261          */
 262         rval = 0;
 263         while (XFS_BULKSTAT_UBLEFT(ubleft) && agno < mp->m_sb.sb_agcount) {
 264                 cond_resched();
 265                 error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
 266                 if (error) {
 267                         /*
 268                          * Skip this allocation group and go to the next one.
 269                          */
 270                         agno++;
 271                         agino = 0;
 272                         continue;
 273                 }
 274                 agi = XFS_BUF_TO_AGI(agbp);
 275                 /*
 276                  * Allocate and initialize a btree cursor for ialloc btree.
 277                  */
 278                 cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno);
 279                 irbp = irbuf;
 280                 irbufend = irbuf + nirbuf;
 281                 end_of_ag = 0;
 282                 /*
 283                  * If we're returning in the middle of an allocation group,
 284                  * we need to get the remainder of the chunk we're in.
 285                  */
 286                 if (agino > 0) {
 287                         xfs_inobt_rec_incore_t r;
 288
 289                         /*
 290                          * Lookup the inode chunk that this inode lives in.
 291                          */
 292                         error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE,
 293                                                  &tmp);
 294                         if (!error &&   /* no I/O error */
 295                             tmp &&      /* lookup succeeded */
 296                                         /* got the record, should always work */
 297                             !(error = xfs_inobt_get_rec(cur, &r, &i)) &&
 298                             i == 1 &&
 299                                         /* this is the right chunk */
 300                             agino < r.ir_startino + XFS_INODES_PER_CHUNK &&
 301                                         /* lastino was not last in chunk */
 302                             (chunkidx = agino - r.ir_startino + 1) <
 303                                     XFS_INODES_PER_CHUNK &&
 304                                         /* there are some left allocated */
 305                             xfs_inobt_maskn(chunkidx,
 306                                     XFS_INODES_PER_CHUNK - chunkidx) &
 307                                     ~r.ir_free) {
 308                                 /*
 309                                  * Grab the chunk record.  Mark all the
 310                                  * uninteresting inodes (because they're
 311                                  * before our start point) free.
 312                                  */
 313                                 for (i = 0; i < chunkidx; i++) {
 314                                         if (XFS_INOBT_MASK(i) & ~r.ir_free)
 315                                                 r.ir_freecount++;
 316                                 }
 317                                 r.ir_free |= xfs_inobt_maskn(0, chunkidx);
 318                                 irbp->ir_startino = r.ir_startino;
 319                                 irbp->ir_freecount = r.ir_freecount;
 320                                 irbp->ir_free = r.ir_free;
 321                                 irbp++;
 322                                 agino = r.ir_startino + XFS_INODES_PER_CHUNK;
 323                                 icount = XFS_INODES_PER_CHUNK - r.ir_freecount;
 324                         } else {
 325                                 /*
 326                                  * If any of those tests failed, bump the
 327                                  * inode number (just in case).
 328                                  */
 329                                 agino++;
 330                                 icount = 0;
 331                         }
 332                         /*
 333                          * In any case, increment to the next record.
 334                          */
 335                         if (!error)
 336                                 error = xfs_btree_increment(cur, 0, &tmp);
 337                 } else {
 338                         /*
 339                          * Start of ag.  Lookup the first inode chunk.
 340                          */
 341                         error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &tmp);
 342                         icount = 0;
 343                 }
 344                 /*
 345                  * Loop through inode btree records in this ag,
 346                  * until we run out of inodes or space in the buffer.
 347                  */
 348                 while (irbp < irbufend && icount < ubcount) {
 349                         xfs_inobt_rec_incore_t r;
 350
 351                         /*
 352                          * Loop as long as we're unable to read the
 353                          * inode btree.
 354                          */
 355                         while (error) {
 356                                 agino += XFS_INODES_PER_CHUNK;
 357                                 if (XFS_AGINO_TO_AGBNO(mp, agino) >=
 358                                                 be32_to_cpu(agi->agi_length))
 359                                         break;
 360                                 error = xfs_inobt_lookup(cur, agino,
 361                                                          XFS_LOOKUP_GE, &tmp);
 362                                 cond_resched();
 363                         }
 364                         /*
 365                          * If ran off the end of the ag either with an error,
 366                          * or the normal way, set end and stop collecting.
 367                          */
 368                         if (error) {
 369                                 end_of_ag = 1;
 370                                 break;
 371                         }
 372
 373                         error = xfs_inobt_get_rec(cur, &r, &i);
 374                         if (error || i == 0) {
 375                                 end_of_ag = 1;
 376                                 break;
 377                         }
 378
 379                         /*
 380                          * If this chunk has any allocated inodes, save it.
 381                          * Also start read-ahead now for this chunk.
 382                          */
 383                         if (r.ir_freecount < XFS_INODES_PER_CHUNK) {
 384                                 struct blk_plug plug;
 385                                 /*
 386                                  * Loop over all clusters in the next chunk.
 387                                  * Do a readahead if there are any allocated
 388                                  * inodes in that cluster.
 389                                  */
 390                                 blk_start_plug(&plug);
 391                                 agbno = XFS_AGINO_TO_AGBNO(mp, r.ir_startino);
 392                                 for (chunkidx = 0;
 393                                      chunkidx < XFS_INODES_PER_CHUNK;
 394                                      chunkidx += nicluster,
 395                                      agbno += nbcluster) {
 396                                         if (xfs_inobt_maskn(chunkidx, nicluster)
 397                                                         & ~r.ir_free)
 398                                                 xfs_btree_reada_bufs(mp, agno,
 399                                                         agbno, nbcluster,
 400                                                         &xfs_inode_buf_ops);
 401                                 }
 402                                 blk_finish_plug(&plug);
 403                                 irbp->ir_startino = r.ir_startino;
 404                                 irbp->ir_freecount = r.ir_freecount;
 405                                 irbp->ir_free = r.ir_free;
 406                                 irbp++;
 407                                 icount += XFS_INODES_PER_CHUNK - r.ir_freecount;
 408                         }
 409                         /*
 410                          * Set agino to after this chunk and bump the cursor.
 411                          */
 412                         agino = r.ir_startino + XFS_INODES_PER_CHUNK;
 413                         error = xfs_btree_increment(cur, 0, &tmp);
 414                         cond_resched();
 415                 }
 416                 /*
 417                  * Drop the btree buffers and the agi buffer.
 418                  * We can't hold any of the locks these represent
 419                  * when calling iget.
 420                  */
 421                 xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
 422                 xfs_buf_relse(agbp);
 423                 /*
 424                  * Now format all the good inodes into the user's buffer.
 425                  */
 426                 irbufend = irbp;
 427                 for (irbp = irbuf;
 428                      irbp < irbufend && XFS_BULKSTAT_UBLEFT(ubleft); irbp++) {
 429                         /*
 430                          * Now process this chunk of inodes.
 431                          */
 432                         for (agino = irbp->ir_startino, chunkidx = clustidx = 0;
 433                              XFS_BULKSTAT_UBLEFT(ubleft) &&
 434                                 irbp->ir_freecount < XFS_INODES_PER_CHUNK;
 435                              chunkidx++, clustidx++, agino++) {
 436                                 ASSERT(chunkidx < XFS_INODES_PER_CHUNK);
 437
 438                                 ino = XFS_AGINO_TO_INO(mp, agno, agino);
 439                                 /*
 440                                  * Skip if this inode is free.
 441                                  */
 442                                 if (XFS_INOBT_MASK(chunkidx) & irbp->ir_free) {
 443                                         lastino = ino;
 444                                         continue;
 445                                 }
 446                                 /*
 447                                  * Count used inodes as free so we can tell
 448                                  * when the chunk is used up.
 449                                  */
 450                                 irbp->ir_freecount++;
 451
 452                                 /*
 453                                  * Get the inode and fill in a single buffer.
 454                                  */
 455                                 ubused = statstruct_size;
 456                                 error = formatter(mp, ino, ubufp, ubleft,
 457                                                   &ubused, &fmterror);
 458                                 if (fmterror == BULKSTAT_RV_NOTHING) {
 459                                         if (error && error != ENOENT &&
 460                                                 error != EINVAL) {
 461                                                 ubleft = 0;
 462                                                 rval = error;
 463                                                 break;
 464                                         }
 465                                         lastino = ino;
 466                                         continue;
 467                                 }
 468                                 if (fmterror == BULKSTAT_RV_GIVEUP) {
 469                                         ubleft = 0;
 470                                         ASSERT(error);
 471                                         rval = error;
 472                                         break;
 473                                 }
 474                                 if (ubufp)
 475                                         ubufp += ubused;
 476                                 ubleft -= ubused;
 477                                 ubelem++;
 478                                 lastino = ino;
 479                         }
 480
 481                         cond_resched();
 482                 }
 483                 /*
 484                  * Set up for the next loop iteration.
 485                  */
 486                 if (XFS_BULKSTAT_UBLEFT(ubleft)) {
 487                         if (end_of_ag) {
 488                                 agno++;
 489                                 agino = 0;
 490                         } else
 491                                 agino = XFS_INO_TO_AGINO(mp, lastino);
 492                 } else
 493                         break;
 494         }
 495         /*
 496          * Done, we're either out of filesystem or space to put the data.
 497          */
 498         kmem_free_large(irbuf);
 499         *ubcountp = ubelem;
 500         /*
 501          * Found some inodes, return them now and return the error next time.
 502          */
 503         if (ubelem)
 504                 rval = 0;
 505         if (agno >= mp->m_sb.sb_agcount) {
 506                 /*
 507                  * If we ran out of filesystem, mark lastino as off
 508                  * the end of the filesystem, so the next call
 509                  * will return immediately.
 510                  */
 511                 *lastinop = (xfs_ino_t)XFS_AGINO_TO_INO(mp, agno, 0);
 512                 *done = 1;
 513         } else
 514                 *lastinop = (xfs_ino_t)lastino;
 515
 516         return rval;
 517 }
 518
 519 /*
 520  * Return stat information in bulk (by-inode) for the filesystem.
 521  * Special case for non-sequential one inode bulkstat.
 522  */
 523 int                                     /* error status */
 524 xfs_bulkstat_single(
 525         xfs_mount_t             *mp,    /* mount point for filesystem */
 526         xfs_ino_t               *lastinop, /* inode to return */
 527         char                    __user *buffer, /* buffer with inode stats */
 528         int                     *done)  /* 1 if there are more stats to get */
 529 {
 530         int                     count;  /* count value for bulkstat call */
 531         int                     error;  /* return value */
 532         xfs_ino_t               ino;    /* filesystem inode number */
 533         int                     res;    /* result from bs1 */
 534
 535         /*
 536          * note that requesting valid inode numbers which are not allocated
 537          * to inodes will most likely cause xfs_imap_to_bp to generate warning
 538          * messages about bad magic numbers. This is ok. The fact that
 539          * the inode isn't actually an inode is handled by the
 540          * error check below. Done this way to make the usual case faster
 541          * at the expense of the error case.
 542          */
 543
 544         ino = (xfs_ino_t)*lastinop;
 545         error = xfs_bulkstat_one(mp, ino, buffer, sizeof(xfs_bstat_t), 0, &res);
 546         if (error) {
 547                 /*
 548                  * Special case way failed, do it the "long" way
 549                  * to see if that works.
 550                  */
 551                 (*lastinop)--;
 552                 count = 1;
 553                 if (xfs_bulkstat(mp, lastinop, &count, xfs_bulkstat_one,
 554                                 sizeof(xfs_bstat_t), buffer, done))
 555                         return error;
 556                 if (count == 0 || (xfs_ino_t)*lastinop != ino)
 557                         return error == EFSCORRUPTED ?
 558                                 XFS_ERROR(EINVAL) : error;
 559                 else
 560                         return 0;
 561         }
 562         *done = 0;
 563         return 0;
 564 }
 565
 566 int
 567 xfs_inumbers_fmt(
 568         void                    __user *ubuffer, /* buffer to write to */
 569         const xfs_inogrp_t      *buffer,        /* buffer to read from */
 570         long                    count,          /* # of elements to read */
 571         long                    *written)       /* # of bytes written */
 572 {
 573         if (copy_to_user(ubuffer, buffer, count * sizeof(*buffer)))
 574                 return -EFAULT;
 575         *written = count * sizeof(*buffer);
 576         return 0;
 577 }
 578
 579 /*
 580  * Return inode number table for the filesystem.
 581  */
 582 int                                     /* error status */
 583 xfs_inumbers(
 584         xfs_mount_t     *mp,            /* mount point for filesystem */
 585         xfs_ino_t       *lastino,       /* last inode returned */
 586         int             *count,         /* size of buffer/count returned */
 587         void            __user *ubuffer,/* buffer with inode descriptions */
 588         inumbers_fmt_pf formatter)
 589 {
 590         xfs_buf_t       *agbp;
 591         xfs_agino_t     agino;
 592         xfs_agnumber_t  agno;
 593         int             bcount;
 594         xfs_inogrp_t    *buffer;
 595         int             bufidx;
 596         xfs_btree_cur_t *cur;
 597         int             error;
 598         xfs_inobt_rec_incore_t r;
 599         int             i;
 600         xfs_ino_t       ino;
 601         int             left;
 602         int             tmp;
 603
 604         ino = (xfs_ino_t)*lastino;
 605         agno = XFS_INO_TO_AGNO(mp, ino);
 606         agino = XFS_INO_TO_AGINO(mp, ino);
 607         left = *count;
 608         *count = 0;
 609         bcount = MIN(left, (int)(PAGE_SIZE / sizeof(*buffer)));
 610         buffer = kmem_alloc(bcount * sizeof(*buffer), KM_SLEEP);
 611         error = bufidx = 0;
 612         cur = NULL;
 613         agbp = NULL;
 614         while (left > 0 && agno < mp->m_sb.sb_agcount) {
 615                 if (agbp == NULL) {
 616                         error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
 617                         if (error) {
 618                                 /*
 619                                  * If we can't read the AGI of this ag,
 620                                  * then just skip to the next one.
 621                                  */
 622                                 ASSERT(cur == NULL);
 623                                 agbp = NULL;
 624                                 agno++;
 625                                 agino = 0;
 626                                 continue;
 627                         }
 628                         cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno);
 629                         error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_GE,
 630                                                  &tmp);
 631                         if (error) {
 632                                 xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
 633                                 cur = NULL;
 634                                 xfs_buf_relse(agbp);
 635                                 agbp = NULL;
 636                                 /*
 637                                  * Move up the last inode in the current
 638                                  * chunk.  The lookup_ge will always get
 639                                  * us the first inode in the next chunk.
 640                                  */
 641                                 agino += XFS_INODES_PER_CHUNK - 1;
 642                                 continue;
 643                         }
 644                 }
 645                 error = xfs_inobt_get_rec(cur, &r, &i);
 646                 if (error || i == 0) {
 647                         xfs_buf_relse(agbp);
 648                         agbp = NULL;
 649                         xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
 650                         cur = NULL;
 651                         agno++;
 652                         agino = 0;
 653                         continue;
 654                 }
 655                 agino = r.ir_startino + XFS_INODES_PER_CHUNK - 1;
 656                 buffer[bufidx].xi_startino =
 657                         XFS_AGINO_TO_INO(mp, agno, r.ir_startino);
 658                 buffer[bufidx].xi_alloccount =
 659                         XFS_INODES_PER_CHUNK - r.ir_freecount;
 660                 buffer[bufidx].xi_allocmask = ~r.ir_free;
 661                 bufidx++;
 662                 left--;
 663                 if (bufidx == bcount) {
 664                         long written;
 665                         if (formatter(ubuffer, buffer, bufidx, &written)) {
 666                                 error = XFS_ERROR(EFAULT);
 667                                 break;
 668                         }
 669                         ubuffer += written;
 670                         *count += bufidx;
 671                         bufidx = 0;
 672                 }
 673                 if (left) {
 674                         error = xfs_btree_increment(cur, 0, &tmp);
 675                         if (error) {
 676                                 xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
 677                                 cur = NULL;
 678                                 xfs_buf_relse(agbp);
 679                                 agbp = NULL;
 680                                 /*
 681                                  * The agino value has already been bumped.
 682                                  * Just try to skip up to it.
 683                                  */
 684                                 agino += XFS_INODES_PER_CHUNK;
 685                                 continue;
 686                         }
 687                 }
 688         }
 689         if (!error) {
 690                 if (bufidx) {
 691                         long written;
 692                         if (formatter(ubuffer, buffer, bufidx, &written))
 693                                 error = XFS_ERROR(EFAULT);
 694                         else
 695                                 *count += bufidx;
 696                 }
 697                 *lastino = XFS_AGINO_TO_INO(mp, agno, agino);
 698         }
 699         kmem_free(buffer);
 700         if (cur)
 701                 xfs_btree_del_cursor(cur, (error ? XFS_BTREE_ERROR :
 702                                            XFS_BTREE_NOERROR));
 703         if (agbp)
 704                 xfs_buf_relse(agbp);
 705         return error;
 706 }