linux/fs/xfs/xfs_itable.c
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   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
  39STATIC int
  40xfs_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 */
  53int
  54xfs_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 */
 150STATIC int
 151xfs_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
 166int
 167xfs_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 */
 184int                                     /* error status */
 185xfs_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(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 */
 523int                                     /* error status */
 524xfs_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 = *lastinop;
 545        error = xfs_bulkstat_one(mp, ino, buffer, sizeof(xfs_bstat_t),
 546                                 NULL, &res);
 547        if (error) {
 548                /*
 549                 * Special case way failed, do it the "long" way
 550                 * to see if that works.
 551                 */
 552                (*lastinop)--;
 553                count = 1;
 554                if (xfs_bulkstat(mp, lastinop, &count, xfs_bulkstat_one,
 555                                sizeof(xfs_bstat_t), buffer, done))
 556                        return error;
 557                if (count == 0 || (xfs_ino_t)*lastinop != ino)
 558                        return error == EFSCORRUPTED ?
 559                                XFS_ERROR(EINVAL) : error;
 560                else
 561                        return 0;
 562        }
 563        *done = 0;
 564        return 0;
 565}
 566
 567int
 568xfs_inumbers_fmt(
 569        void                    __user *ubuffer, /* buffer to write to */
 570        const xfs_inogrp_t      *buffer,        /* buffer to read from */
 571        long                    count,          /* # of elements to read */
 572        long                    *written)       /* # of bytes written */
 573{
 574        if (copy_to_user(ubuffer, buffer, count * sizeof(*buffer)))
 575                return -EFAULT;
 576        *written = count * sizeof(*buffer);
 577        return 0;
 578}
 579
 580/*
 581 * Return inode number table for the filesystem.
 582 */
 583int                                     /* error status */
 584xfs_inumbers(
 585        xfs_mount_t     *mp,            /* mount point for filesystem */
 586        xfs_ino_t       *lastino,       /* last inode returned */
 587        int             *count,         /* size of buffer/count returned */
 588        void            __user *ubuffer,/* buffer with inode descriptions */
 589        inumbers_fmt_pf formatter)
 590{
 591        xfs_buf_t       *agbp;
 592        xfs_agino_t     agino;
 593        xfs_agnumber_t  agno;
 594        int             bcount;
 595        xfs_inogrp_t    *buffer;
 596        int             bufidx;
 597        xfs_btree_cur_t *cur;
 598        int             error;
 599        xfs_inobt_rec_incore_t r;
 600        int             i;
 601        xfs_ino_t       ino;
 602        int             left;
 603        int             tmp;
 604
 605        ino = (xfs_ino_t)*lastino;
 606        agno = XFS_INO_TO_AGNO(mp, ino);
 607        agino = XFS_INO_TO_AGINO(mp, ino);
 608        left = *count;
 609        *count = 0;
 610        bcount = MIN(left, (int)(PAGE_SIZE / sizeof(*buffer)));
 611        buffer = kmem_alloc(bcount * sizeof(*buffer), KM_SLEEP);
 612        error = bufidx = 0;
 613        cur = NULL;
 614        agbp = NULL;
 615        while (left > 0 && agno < mp->m_sb.sb_agcount) {
 616                if (agbp == NULL) {
 617                        error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
 618                        if (error) {
 619                                /*
 620                                 * If we can't read the AGI of this ag,
 621                                 * then just skip to the next one.
 622                                 */
 623                                ASSERT(cur == NULL);
 624                                agbp = NULL;
 625                                agno++;
 626                                agino = 0;
 627                                continue;
 628                        }
 629                        cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno);
 630                        error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_GE,
 631                                                 &tmp);
 632                        if (error) {
 633                                xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
 634                                cur = NULL;
 635                                xfs_buf_relse(agbp);
 636                                agbp = NULL;
 637                                /*
 638                                 * Move up the last inode in the current
 639                                 * chunk.  The lookup_ge will always get
 640                                 * us the first inode in the next chunk.
 641                                 */
 642                                agino += XFS_INODES_PER_CHUNK - 1;
 643                                continue;
 644                        }
 645                }
 646                error = xfs_inobt_get_rec(cur, &r, &i);
 647                if (error || i == 0) {
 648                        xfs_buf_relse(agbp);
 649                        agbp = NULL;
 650                        xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
 651                        cur = NULL;
 652                        agno++;
 653                        agino = 0;
 654                        continue;
 655                }
 656                agino = r.ir_startino + XFS_INODES_PER_CHUNK - 1;
 657                buffer[bufidx].xi_startino =
 658                        XFS_AGINO_TO_INO(mp, agno, r.ir_startino);
 659                buffer[bufidx].xi_alloccount =
 660                        XFS_INODES_PER_CHUNK - r.ir_freecount;
 661                buffer[bufidx].xi_allocmask = ~r.ir_free;
 662                bufidx++;
 663                left--;
 664                if (bufidx == bcount) {
 665                        long written;
 666                        if (formatter(ubuffer, buffer, bufidx, &written)) {
 667                                error = XFS_ERROR(EFAULT);
 668                                break;
 669                        }
 670                        ubuffer += written;
 671                        *count += bufidx;
 672                        bufidx = 0;
 673                }
 674                if (left) {
 675                        error = xfs_btree_increment(cur, 0, &tmp);
 676                        if (error) {
 677                                xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
 678                                cur = NULL;
 679                                xfs_buf_relse(agbp);
 680                                agbp = NULL;
 681                                /*
 682                                 * The agino value has already been bumped.
 683                                 * Just try to skip up to it.
 684                                 */
 685                                agino += XFS_INODES_PER_CHUNK;
 686                                continue;
 687                        }
 688                }
 689        }
 690        if (!error) {
 691                if (bufidx) {
 692                        long written;
 693                        if (formatter(ubuffer, buffer, bufidx, &written))
 694                                error = XFS_ERROR(EFAULT);
 695                        else
 696                                *count += bufidx;
 697                }
 698                *lastino = XFS_AGINO_TO_INO(mp, agno, agino);
 699        }
 700        kmem_free(buffer);
 701        if (cur)
 702                xfs_btree_del_cursor(cur, (error ? XFS_BTREE_ERROR :
 703                                           XFS_BTREE_NOERROR));
 704        if (agbp)
 705                xfs_buf_relse(agbp);
 706        return error;
 707}
 708