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xfs_inode.c

/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_imap.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_buf_item.h"
#include "xfs_inode_item.h"
#include "xfs_btree.h"
#include "xfs_alloc.h"
#include "xfs_ialloc.h"
#include "xfs_bmap.h"
#include "xfs_rw.h"
#include "xfs_error.h"
#include "xfs_utils.h"
#include "xfs_dir2_trace.h"
#include "xfs_quota.h"
#include "xfs_acl.h"
#include "xfs_filestream.h"
#include "xfs_vnodeops.h"

kmem_zone_t *xfs_ifork_zone;
kmem_zone_t *xfs_inode_zone;
kmem_zone_t *xfs_icluster_zone;

/*
 * Used in xfs_itruncate().  This is the maximum number of extents
 * freed from a file in a single transaction.
 */
#define     XFS_ITRUNC_MAX_EXTENTS  2

STATIC int xfs_iflush_int(xfs_inode_t *, xfs_buf_t *);
STATIC int xfs_iformat_local(xfs_inode_t *, xfs_dinode_t *, int, int);
STATIC int xfs_iformat_extents(xfs_inode_t *, xfs_dinode_t *, int);
STATIC int xfs_iformat_btree(xfs_inode_t *, xfs_dinode_t *, int);

#ifdef DEBUG
/*
 * Make sure that the extents in the given memory buffer
 * are valid.
 */
STATIC void
xfs_validate_extents(
      xfs_ifork_t       *ifp,
      int               nrecs,
      xfs_exntfmt_t           fmt)
{
      xfs_bmbt_irec_t         irec;
      xfs_bmbt_rec_host_t     rec;
      int               i;

      for (i = 0; i < nrecs; i++) {
            xfs_bmbt_rec_host_t *ep = xfs_iext_get_ext(ifp, i);
            rec.l0 = get_unaligned(&ep->l0);
            rec.l1 = get_unaligned(&ep->l1);
            xfs_bmbt_get_all(&rec, &irec);
            if (fmt == XFS_EXTFMT_NOSTATE)
                  ASSERT(irec.br_state == XFS_EXT_NORM);
      }
}
#else /* DEBUG */
#define xfs_validate_extents(ifp, nrecs, fmt)
#endif /* DEBUG */

/*
 * Check that none of the inode's in the buffer have a next
 * unlinked field of 0.
 */
#if defined(DEBUG)
void
xfs_inobp_check(
      xfs_mount_t *mp,
      xfs_buf_t   *bp)
{
      int         i;
      int         j;
      xfs_dinode_t      *dip;

      j = mp->m_inode_cluster_size >> mp->m_sb.sb_inodelog;

      for (i = 0; i < j; i++) {
            dip = (xfs_dinode_t *)xfs_buf_offset(bp,
                              i * mp->m_sb.sb_inodesize);
            if (!dip->di_next_unlinked)  {
                  xfs_fs_cmn_err(CE_ALERT, mp,
                        "Detected a bogus zero next_unlinked field in incore inode buffer 0x%p.  About to pop an ASSERT.",
                        bp);
                  ASSERT(dip->di_next_unlinked);
            }
      }
}
#endif

/*
 * This routine is called to map an inode number within a file
 * system to the buffer containing the on-disk version of the
 * inode.  It returns a pointer to the buffer containing the
 * on-disk inode in the bpp parameter, and in the dip parameter
 * it returns a pointer to the on-disk inode within that buffer.
 *
 * If a non-zero error is returned, then the contents of bpp and
 * dipp are undefined.
 *
 * Use xfs_imap() to determine the size and location of the
 * buffer to read from disk.
 */
STATIC int
xfs_inotobp(
      xfs_mount_t *mp,
      xfs_trans_t *tp,
      xfs_ino_t   ino,
      xfs_dinode_t      **dipp,
      xfs_buf_t   **bpp,
      int         *offset)
{
      int         di_ok;
      xfs_imap_t  imap;
      xfs_buf_t   *bp;
      int         error;
      xfs_dinode_t      *dip;

      /*
       * Call the space management code to find the location of the
       * inode on disk.
       */
      imap.im_blkno = 0;
      error = xfs_imap(mp, tp, ino, &imap, XFS_IMAP_LOOKUP);
      if (error != 0) {
            cmn_err(CE_WARN,
      "xfs_inotobp: xfs_imap()  returned an "
      "error %d on %s.  Returning error.", error, mp->m_fsname);
            return error;
      }

      /*
       * If the inode number maps to a block outside the bounds of the
       * file system then return NULL rather than calling read_buf
       * and panicing when we get an error from the driver.
       */
      if ((imap.im_blkno + imap.im_len) >
          XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)) {
            cmn_err(CE_WARN,
      "xfs_inotobp: inode number (%llu + %d) maps to a block outside the bounds "
      "of the file system %s.  Returning EINVAL.",
                  (unsigned long long)imap.im_blkno,
                  imap.im_len, mp->m_fsname);
            return XFS_ERROR(EINVAL);
      }

      /*
       * Read in the buffer.  If tp is NULL, xfs_trans_read_buf() will
       * default to just a read_buf() call.
       */
      error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap.im_blkno,
                           (int)imap.im_len, XFS_BUF_LOCK, &bp);

      if (error) {
            cmn_err(CE_WARN,
      "xfs_inotobp: xfs_trans_read_buf()  returned an "
      "error %d on %s.  Returning error.", error, mp->m_fsname);
            return error;
      }
      dip = (xfs_dinode_t *)xfs_buf_offset(bp, 0);
      di_ok =
            be16_to_cpu(dip->di_core.di_magic) == XFS_DINODE_MAGIC &&
            XFS_DINODE_GOOD_VERSION(dip->di_core.di_version);
      if (unlikely(XFS_TEST_ERROR(!di_ok, mp, XFS_ERRTAG_ITOBP_INOTOBP,
                  XFS_RANDOM_ITOBP_INOTOBP))) {
            XFS_CORRUPTION_ERROR("xfs_inotobp", XFS_ERRLEVEL_LOW, mp, dip);
            xfs_trans_brelse(tp, bp);
            cmn_err(CE_WARN,
      "xfs_inotobp: XFS_TEST_ERROR()  returned an "
      "error on %s.  Returning EFSCORRUPTED.",  mp->m_fsname);
            return XFS_ERROR(EFSCORRUPTED);
      }

      xfs_inobp_check(mp, bp);

      /*
       * Set *dipp to point to the on-disk inode in the buffer.
       */
      *dipp = (xfs_dinode_t *)xfs_buf_offset(bp, imap.im_boffset);
      *bpp = bp;
      *offset = imap.im_boffset;
      return 0;
}


/*
 * This routine is called to map an inode to the buffer containing
 * the on-disk version of the inode.  It returns a pointer to the
 * buffer containing the on-disk inode in the bpp parameter, and in
 * the dip parameter it returns a pointer to the on-disk inode within
 * that buffer.
 *
 * If a non-zero error is returned, then the contents of bpp and
 * dipp are undefined.
 *
 * If the inode is new and has not yet been initialized, use xfs_imap()
 * to determine the size and location of the buffer to read from disk.
 * If the inode has already been mapped to its buffer and read in once,
 * then use the mapping information stored in the inode rather than
 * calling xfs_imap().  This allows us to avoid the overhead of looking
 * at the inode btree for small block file systems (see xfs_dilocate()).
 * We can tell whether the inode has been mapped in before by comparing
 * its disk block address to 0.  Only uninitialized inodes will have
 * 0 for the disk block address.
 */
int
xfs_itobp(
      xfs_mount_t *mp,
      xfs_trans_t *tp,
      xfs_inode_t *ip,
      xfs_dinode_t      **dipp,
      xfs_buf_t   **bpp,
      xfs_daddr_t bno,
      uint        imap_flags)
{
      xfs_imap_t  imap;
      xfs_buf_t   *bp;
      int         error;
      int         i;
      int         ni;

      if (ip->i_blkno == (xfs_daddr_t)0) {
            /*
             * Call the space management code to find the location of the
             * inode on disk.
             */
            imap.im_blkno = bno;
            if ((error = xfs_imap(mp, tp, ip->i_ino, &imap,
                              XFS_IMAP_LOOKUP | imap_flags)))
                  return error;

            /*
             * If the inode number maps to a block outside the bounds
             * of the file system then return NULL rather than calling
             * read_buf and panicing when we get an error from the
             * driver.
             */
            if ((imap.im_blkno + imap.im_len) >
                XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)) {
#ifdef DEBUG
                  xfs_fs_cmn_err(CE_ALERT, mp, "xfs_itobp: "
                              "(imap.im_blkno (0x%llx) "
                              "+ imap.im_len (0x%llx)) > "
                              " XFS_FSB_TO_BB(mp, "
                              "mp->m_sb.sb_dblocks) (0x%llx)",
                              (unsigned long long) imap.im_blkno,
                              (unsigned long long) imap.im_len,
                              XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks));
#endif /* DEBUG */
                  return XFS_ERROR(EINVAL);
            }

            /*
             * Fill in the fields in the inode that will be used to
             * map the inode to its buffer from now on.
             */
            ip->i_blkno = imap.im_blkno;
            ip->i_len = imap.im_len;
            ip->i_boffset = imap.im_boffset;
      } else {
            /*
             * We've already mapped the inode once, so just use the
             * mapping that we saved the first time.
             */
            imap.im_blkno = ip->i_blkno;
            imap.im_len = ip->i_len;
            imap.im_boffset = ip->i_boffset;
      }
      ASSERT(bno == 0 || bno == imap.im_blkno);

      /*
       * Read in the buffer.  If tp is NULL, xfs_trans_read_buf() will
       * default to just a read_buf() call.
       */
      error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap.im_blkno,
                           (int)imap.im_len, XFS_BUF_LOCK, &bp);
      if (error) {
#ifdef DEBUG
            xfs_fs_cmn_err(CE_ALERT, mp, "xfs_itobp: "
                        "xfs_trans_read_buf() returned error %d, "
                        "imap.im_blkno 0x%llx, imap.im_len 0x%llx",
                        error, (unsigned long long) imap.im_blkno,
                        (unsigned long long) imap.im_len);
#endif /* DEBUG */
            return error;
      }

      /*
       * Validate the magic number and version of every inode in the buffer
       * (if DEBUG kernel) or the first inode in the buffer, otherwise.
       * No validation is done here in userspace (xfs_repair).
       */
#if !defined(__KERNEL__)
      ni = 0;
#elif defined(DEBUG)
      ni = BBTOB(imap.im_len) >> mp->m_sb.sb_inodelog;
#else /* usual case */
      ni = 1;
#endif

      for (i = 0; i < ni; i++) {
            int         di_ok;
            xfs_dinode_t      *dip;

            dip = (xfs_dinode_t *)xfs_buf_offset(bp,
                              (i << mp->m_sb.sb_inodelog));
            di_ok = be16_to_cpu(dip->di_core.di_magic) == XFS_DINODE_MAGIC &&
                      XFS_DINODE_GOOD_VERSION(dip->di_core.di_version);
            if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
                                    XFS_ERRTAG_ITOBP_INOTOBP,
                                    XFS_RANDOM_ITOBP_INOTOBP))) {
                  if (imap_flags & XFS_IMAP_BULKSTAT) {
                        xfs_trans_brelse(tp, bp);
                        return XFS_ERROR(EINVAL);
                  }
#ifdef DEBUG
                  cmn_err(CE_ALERT,
                              "Device %s - bad inode magic/vsn "
                              "daddr %lld #%d (magic=%x)",
                        XFS_BUFTARG_NAME(mp->m_ddev_targp),
                        (unsigned long long)imap.im_blkno, i,
                        be16_to_cpu(dip->di_core.di_magic));
#endif
                  XFS_CORRUPTION_ERROR("xfs_itobp", XFS_ERRLEVEL_HIGH,
                                   mp, dip);
                  xfs_trans_brelse(tp, bp);
                  return XFS_ERROR(EFSCORRUPTED);
            }
      }

      xfs_inobp_check(mp, bp);

      /*
       * Mark the buffer as an inode buffer now that it looks good
       */
      XFS_BUF_SET_VTYPE(bp, B_FS_INO);

      /*
       * Set *dipp to point to the on-disk inode in the buffer.
       */
      *dipp = (xfs_dinode_t *)xfs_buf_offset(bp, imap.im_boffset);
      *bpp = bp;
      return 0;
}

/*
 * Move inode type and inode format specific information from the
 * on-disk inode to the in-core inode.  For fifos, devs, and sockets
 * this means set if_rdev to the proper value.  For files, directories,
 * and symlinks this means to bring in the in-line data or extent
 * pointers.  For a file in B-tree format, only the root is immediately
 * brought in-core.  The rest will be in-lined in if_extents when it
 * is first referenced (see xfs_iread_extents()).
 */
STATIC int
xfs_iformat(
      xfs_inode_t       *ip,
      xfs_dinode_t            *dip)
{
      xfs_attr_shortform_t    *atp;
      int               size;
      int               error;
      xfs_fsize_t             di_size;
      ip->i_df.if_ext_max =
            XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
      error = 0;

      if (unlikely(be32_to_cpu(dip->di_core.di_nextents) +
                 be16_to_cpu(dip->di_core.di_anextents) >
                 be64_to_cpu(dip->di_core.di_nblocks))) {
            xfs_fs_repair_cmn_err(CE_WARN, ip->i_mount,
                  "corrupt dinode %Lu, extent total = %d, nblocks = %Lu.",
                  (unsigned long long)ip->i_ino,
                  (int)(be32_to_cpu(dip->di_core.di_nextents) +
                        be16_to_cpu(dip->di_core.di_anextents)),
                  (unsigned long long)
                        be64_to_cpu(dip->di_core.di_nblocks));
            XFS_CORRUPTION_ERROR("xfs_iformat(1)", XFS_ERRLEVEL_LOW,
                             ip->i_mount, dip);
            return XFS_ERROR(EFSCORRUPTED);
      }

      if (unlikely(dip->di_core.di_forkoff > ip->i_mount->m_sb.sb_inodesize)) {
            xfs_fs_repair_cmn_err(CE_WARN, ip->i_mount,
                  "corrupt dinode %Lu, forkoff = 0x%x.",
                  (unsigned long long)ip->i_ino,
                  dip->di_core.di_forkoff);
            XFS_CORRUPTION_ERROR("xfs_iformat(2)", XFS_ERRLEVEL_LOW,
                             ip->i_mount, dip);
            return XFS_ERROR(EFSCORRUPTED);
      }

      switch (ip->i_d.di_mode & S_IFMT) {
      case S_IFIFO:
      case S_IFCHR:
      case S_IFBLK:
      case S_IFSOCK:
            if (unlikely(dip->di_core.di_format != XFS_DINODE_FMT_DEV)) {
                  XFS_CORRUPTION_ERROR("xfs_iformat(3)", XFS_ERRLEVEL_LOW,
                                    ip->i_mount, dip);
                  return XFS_ERROR(EFSCORRUPTED);
            }
            ip->i_d.di_size = 0;
            ip->i_size = 0;
            ip->i_df.if_u2.if_rdev = be32_to_cpu(dip->di_u.di_dev);
            break;

      case S_IFREG:
      case S_IFLNK:
      case S_IFDIR:
            switch (dip->di_core.di_format) {
            case XFS_DINODE_FMT_LOCAL:
                  /*
                   * no local regular files yet
                   */
                  if (unlikely((be16_to_cpu(dip->di_core.di_mode) & S_IFMT) == S_IFREG)) {
                        xfs_fs_repair_cmn_err(CE_WARN, ip->i_mount,
                              "corrupt inode %Lu "
                              "(local format for regular file).",
                              (unsigned long long) ip->i_ino);
                        XFS_CORRUPTION_ERROR("xfs_iformat(4)",
                                         XFS_ERRLEVEL_LOW,
                                         ip->i_mount, dip);
                        return XFS_ERROR(EFSCORRUPTED);
                  }

                  di_size = be64_to_cpu(dip->di_core.di_size);
                  if (unlikely(di_size > XFS_DFORK_DSIZE(dip, ip->i_mount))) {
                        xfs_fs_repair_cmn_err(CE_WARN, ip->i_mount,
                              "corrupt inode %Lu "
                              "(bad size %Ld for local inode).",
                              (unsigned long long) ip->i_ino,
                              (long long) di_size);
                        XFS_CORRUPTION_ERROR("xfs_iformat(5)",
                                         XFS_ERRLEVEL_LOW,
                                         ip->i_mount, dip);
                        return XFS_ERROR(EFSCORRUPTED);
                  }

                  size = (int)di_size;
                  error = xfs_iformat_local(ip, dip, XFS_DATA_FORK, size);
                  break;
            case XFS_DINODE_FMT_EXTENTS:
                  error = xfs_iformat_extents(ip, dip, XFS_DATA_FORK);
                  break;
            case XFS_DINODE_FMT_BTREE:
                  error = xfs_iformat_btree(ip, dip, XFS_DATA_FORK);
                  break;
            default:
                  XFS_ERROR_REPORT("xfs_iformat(6)", XFS_ERRLEVEL_LOW,
                               ip->i_mount);
                  return XFS_ERROR(EFSCORRUPTED);
            }
            break;

      default:
            XFS_ERROR_REPORT("xfs_iformat(7)", XFS_ERRLEVEL_LOW, ip->i_mount);
            return XFS_ERROR(EFSCORRUPTED);
      }
      if (error) {
            return error;
      }
      if (!XFS_DFORK_Q(dip))
            return 0;
      ASSERT(ip->i_afp == NULL);
      ip->i_afp = kmem_zone_zalloc(xfs_ifork_zone, KM_SLEEP);
      ip->i_afp->if_ext_max =
            XFS_IFORK_ASIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
      switch (dip->di_core.di_aformat) {
      case XFS_DINODE_FMT_LOCAL:
            atp = (xfs_attr_shortform_t *)XFS_DFORK_APTR(dip);
            size = be16_to_cpu(atp->hdr.totsize);
            error = xfs_iformat_local(ip, dip, XFS_ATTR_FORK, size);
            break;
      case XFS_DINODE_FMT_EXTENTS:
            error = xfs_iformat_extents(ip, dip, XFS_ATTR_FORK);
            break;
      case XFS_DINODE_FMT_BTREE:
            error = xfs_iformat_btree(ip, dip, XFS_ATTR_FORK);
            break;
      default:
            error = XFS_ERROR(EFSCORRUPTED);
            break;
      }
      if (error) {
            kmem_zone_free(xfs_ifork_zone, ip->i_afp);
            ip->i_afp = NULL;
            xfs_idestroy_fork(ip, XFS_DATA_FORK);
      }
      return error;
}

/*
 * The file is in-lined in the on-disk inode.
 * If it fits into if_inline_data, then copy
 * it there, otherwise allocate a buffer for it
 * and copy the data there.  Either way, set
 * if_data to point at the data.
 * If we allocate a buffer for the data, make
 * sure that its size is a multiple of 4 and
 * record the real size in i_real_bytes.
 */
STATIC int
xfs_iformat_local(
      xfs_inode_t *ip,
      xfs_dinode_t      *dip,
      int         whichfork,
      int         size)
{
      xfs_ifork_t *ifp;
      int         real_size;

      /*
       * If the size is unreasonable, then something
       * is wrong and we just bail out rather than crash in
       * kmem_alloc() or memcpy() below.
       */
      if (unlikely(size > XFS_DFORK_SIZE(dip, ip->i_mount, whichfork))) {
            xfs_fs_repair_cmn_err(CE_WARN, ip->i_mount,
                  "corrupt inode %Lu "
                  "(bad size %d for local fork, size = %d).",
                  (unsigned long long) ip->i_ino, size,
                  XFS_DFORK_SIZE(dip, ip->i_mount, whichfork));
            XFS_CORRUPTION_ERROR("xfs_iformat_local", XFS_ERRLEVEL_LOW,
                             ip->i_mount, dip);
            return XFS_ERROR(EFSCORRUPTED);
      }
      ifp = XFS_IFORK_PTR(ip, whichfork);
      real_size = 0;
      if (size == 0)
            ifp->if_u1.if_data = NULL;
      else if (size <= sizeof(ifp->if_u2.if_inline_data))
            ifp->if_u1.if_data = ifp->if_u2.if_inline_data;
      else {
            real_size = roundup(size, 4);
            ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP);
      }
      ifp->if_bytes = size;
      ifp->if_real_bytes = real_size;
      if (size)
            memcpy(ifp->if_u1.if_data, XFS_DFORK_PTR(dip, whichfork), size);
      ifp->if_flags &= ~XFS_IFEXTENTS;
      ifp->if_flags |= XFS_IFINLINE;
      return 0;
}

/*
 * The file consists of a set of extents all
 * of which fit into the on-disk inode.
 * If there are few enough extents to fit into
 * the if_inline_ext, then copy them there.
 * Otherwise allocate a buffer for them and copy
 * them into it.  Either way, set if_extents
 * to point at the extents.
 */
STATIC int
xfs_iformat_extents(
      xfs_inode_t *ip,
      xfs_dinode_t      *dip,
      int         whichfork)
{
      xfs_bmbt_rec_t    *dp;
      xfs_ifork_t *ifp;
      int         nex;
      int         size;
      int         i;

      ifp = XFS_IFORK_PTR(ip, whichfork);
      nex = XFS_DFORK_NEXTENTS(dip, whichfork);
      size = nex * (uint)sizeof(xfs_bmbt_rec_t);

      /*
       * If the number of extents is unreasonable, then something
       * is wrong and we just bail out rather than crash in
       * kmem_alloc() or memcpy() below.
       */
      if (unlikely(size < 0 || size > XFS_DFORK_SIZE(dip, ip->i_mount, whichfork))) {
            xfs_fs_repair_cmn_err(CE_WARN, ip->i_mount,
                  "corrupt inode %Lu ((a)extents = %d).",
                  (unsigned long long) ip->i_ino, nex);
            XFS_CORRUPTION_ERROR("xfs_iformat_extents(1)", XFS_ERRLEVEL_LOW,
                             ip->i_mount, dip);
            return XFS_ERROR(EFSCORRUPTED);
      }

      ifp->if_real_bytes = 0;
      if (nex == 0)
            ifp->if_u1.if_extents = NULL;
      else if (nex <= XFS_INLINE_EXTS)
            ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
      else
            xfs_iext_add(ifp, 0, nex);

      ifp->if_bytes = size;
      if (size) {
            dp = (xfs_bmbt_rec_t *) XFS_DFORK_PTR(dip, whichfork);
            xfs_validate_extents(ifp, nex, XFS_EXTFMT_INODE(ip));
            for (i = 0; i < nex; i++, dp++) {
                  xfs_bmbt_rec_host_t *ep = xfs_iext_get_ext(ifp, i);
                  ep->l0 = be64_to_cpu(get_unaligned(&dp->l0));
                  ep->l1 = be64_to_cpu(get_unaligned(&dp->l1));
            }
            XFS_BMAP_TRACE_EXLIST(ip, nex, whichfork);
            if (whichfork != XFS_DATA_FORK ||
                  XFS_EXTFMT_INODE(ip) == XFS_EXTFMT_NOSTATE)
                        if (unlikely(xfs_check_nostate_extents(
                            ifp, 0, nex))) {
                              XFS_ERROR_REPORT("xfs_iformat_extents(2)",
                                           XFS_ERRLEVEL_LOW,
                                           ip->i_mount);
                              return XFS_ERROR(EFSCORRUPTED);
                        }
      }
      ifp->if_flags |= XFS_IFEXTENTS;
      return 0;
}

/*
 * The file has too many extents to fit into
 * the inode, so they are in B-tree format.
 * Allocate a buffer for the root of the B-tree
 * and copy the root into it.  The i_extents
 * field will remain NULL until all of the
 * extents are read in (when they are needed).
 */
STATIC int
xfs_iformat_btree(
      xfs_inode_t       *ip,
      xfs_dinode_t            *dip,
      int               whichfork)
{
      xfs_bmdr_block_t  *dfp;
      xfs_ifork_t       *ifp;
      /* REFERENCED */
      int               nrecs;
      int               size;

      ifp = XFS_IFORK_PTR(ip, whichfork);
      dfp = (xfs_bmdr_block_t *)XFS_DFORK_PTR(dip, whichfork);
      size = XFS_BMAP_BROOT_SPACE(dfp);
      nrecs = XFS_BMAP_BROOT_NUMRECS(dfp);

      /*
       * blow out if -- fork has less extents than can fit in
       * fork (fork shouldn't be a btree format), root btree
       * block has more records than can fit into the fork,
       * or the number of extents is greater than the number of
       * blocks.
       */
      if (unlikely(XFS_IFORK_NEXTENTS(ip, whichfork) <= ifp->if_ext_max
          || XFS_BMDR_SPACE_CALC(nrecs) >
                  XFS_DFORK_SIZE(dip, ip->i_mount, whichfork)
          || XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks)) {
            xfs_fs_repair_cmn_err(CE_WARN, ip->i_mount,
                  "corrupt inode %Lu (btree).",
                  (unsigned long long) ip->i_ino);
            XFS_ERROR_REPORT("xfs_iformat_btree", XFS_ERRLEVEL_LOW,
                         ip->i_mount);
            return XFS_ERROR(EFSCORRUPTED);
      }

      ifp->if_broot_bytes = size;
      ifp->if_broot = kmem_alloc(size, KM_SLEEP);
      ASSERT(ifp->if_broot != NULL);
      /*
       * Copy and convert from the on-disk structure
       * to the in-memory structure.
       */
      xfs_bmdr_to_bmbt(dfp, XFS_DFORK_SIZE(dip, ip->i_mount, whichfork),
            ifp->if_broot, size);
      ifp->if_flags &= ~XFS_IFEXTENTS;
      ifp->if_flags |= XFS_IFBROOT;

      return 0;
}

void
xfs_dinode_from_disk(
      xfs_icdinode_t          *to,
      xfs_dinode_core_t *from)
{
      to->di_magic = be16_to_cpu(from->di_magic);
      to->di_mode = be16_to_cpu(from->di_mode);
      to->di_version = from ->di_version;
      to->di_format = from->di_format;
      to->di_onlink = be16_to_cpu(from->di_onlink);
      to->di_uid = be32_to_cpu(from->di_uid);
      to->di_gid = be32_to_cpu(from->di_gid);
      to->di_nlink = be32_to_cpu(from->di_nlink);
      to->di_projid = be16_to_cpu(from->di_projid);
      memcpy(to->di_pad, from->di_pad, sizeof(to->di_pad));
      to->di_flushiter = be16_to_cpu(from->di_flushiter);
      to->di_atime.t_sec = be32_to_cpu(from->di_atime.t_sec);
      to->di_atime.t_nsec = be32_to_cpu(from->di_atime.t_nsec);
      to->di_mtime.t_sec = be32_to_cpu(from->di_mtime.t_sec);
      to->di_mtime.t_nsec = be32_to_cpu(from->di_mtime.t_nsec);
      to->di_ctime.t_sec = be32_to_cpu(from->di_ctime.t_sec);
      to->di_ctime.t_nsec = be32_to_cpu(from->di_ctime.t_nsec);
      to->di_size = be64_to_cpu(from->di_size);
      to->di_nblocks = be64_to_cpu(from->di_nblocks);
      to->di_extsize = be32_to_cpu(from->di_extsize);
      to->di_nextents = be32_to_cpu(from->di_nextents);
      to->di_anextents = be16_to_cpu(from->di_anextents);
      to->di_forkoff = from->di_forkoff;
      to->di_aformat    = from->di_aformat;
      to->di_dmevmask   = be32_to_cpu(from->di_dmevmask);
      to->di_dmstate    = be16_to_cpu(from->di_dmstate);
      to->di_flags      = be16_to_cpu(from->di_flags);
      to->di_gen  = be32_to_cpu(from->di_gen);
}

void
xfs_dinode_to_disk(
      xfs_dinode_core_t *to,
      xfs_icdinode_t          *from)
{
      to->di_magic = cpu_to_be16(from->di_magic);
      to->di_mode = cpu_to_be16(from->di_mode);
      to->di_version = from ->di_version;
      to->di_format = from->di_format;
      to->di_onlink = cpu_to_be16(from->di_onlink);
      to->di_uid = cpu_to_be32(from->di_uid);
      to->di_gid = cpu_to_be32(from->di_gid);
      to->di_nlink = cpu_to_be32(from->di_nlink);
      to->di_projid = cpu_to_be16(from->di_projid);
      memcpy(to->di_pad, from->di_pad, sizeof(to->di_pad));
      to->di_flushiter = cpu_to_be16(from->di_flushiter);
      to->di_atime.t_sec = cpu_to_be32(from->di_atime.t_sec);
      to->di_atime.t_nsec = cpu_to_be32(from->di_atime.t_nsec);
      to->di_mtime.t_sec = cpu_to_be32(from->di_mtime.t_sec);
      to->di_mtime.t_nsec = cpu_to_be32(from->di_mtime.t_nsec);
      to->di_ctime.t_sec = cpu_to_be32(from->di_ctime.t_sec);
      to->di_ctime.t_nsec = cpu_to_be32(from->di_ctime.t_nsec);
      to->di_size = cpu_to_be64(from->di_size);
      to->di_nblocks = cpu_to_be64(from->di_nblocks);
      to->di_extsize = cpu_to_be32(from->di_extsize);
      to->di_nextents = cpu_to_be32(from->di_nextents);
      to->di_anextents = cpu_to_be16(from->di_anextents);
      to->di_forkoff = from->di_forkoff;
      to->di_aformat = from->di_aformat;
      to->di_dmevmask = cpu_to_be32(from->di_dmevmask);
      to->di_dmstate = cpu_to_be16(from->di_dmstate);
      to->di_flags = cpu_to_be16(from->di_flags);
      to->di_gen = cpu_to_be32(from->di_gen);
}

STATIC uint
_xfs_dic2xflags(
      __uint16_t        di_flags)
{
      uint              flags = 0;

      if (di_flags & XFS_DIFLAG_ANY) {
            if (di_flags & XFS_DIFLAG_REALTIME)
                  flags |= XFS_XFLAG_REALTIME;
            if (di_flags & XFS_DIFLAG_PREALLOC)
                  flags |= XFS_XFLAG_PREALLOC;
            if (di_flags & XFS_DIFLAG_IMMUTABLE)
                  flags |= XFS_XFLAG_IMMUTABLE;
            if (di_flags & XFS_DIFLAG_APPEND)
                  flags |= XFS_XFLAG_APPEND;
            if (di_flags & XFS_DIFLAG_SYNC)
                  flags |= XFS_XFLAG_SYNC;
            if (di_flags & XFS_DIFLAG_NOATIME)
                  flags |= XFS_XFLAG_NOATIME;
            if (di_flags & XFS_DIFLAG_NODUMP)
                  flags |= XFS_XFLAG_NODUMP;
            if (di_flags & XFS_DIFLAG_RTINHERIT)
                  flags |= XFS_XFLAG_RTINHERIT;
            if (di_flags & XFS_DIFLAG_PROJINHERIT)
                  flags |= XFS_XFLAG_PROJINHERIT;
            if (di_flags & XFS_DIFLAG_NOSYMLINKS)
                  flags |= XFS_XFLAG_NOSYMLINKS;
            if (di_flags & XFS_DIFLAG_EXTSIZE)
                  flags |= XFS_XFLAG_EXTSIZE;
            if (di_flags & XFS_DIFLAG_EXTSZINHERIT)
                  flags |= XFS_XFLAG_EXTSZINHERIT;
            if (di_flags & XFS_DIFLAG_NODEFRAG)
                  flags |= XFS_XFLAG_NODEFRAG;
            if (di_flags & XFS_DIFLAG_FILESTREAM)
                  flags |= XFS_XFLAG_FILESTREAM;
      }

      return flags;
}

uint
xfs_ip2xflags(
      xfs_inode_t       *ip)
{
      xfs_icdinode_t          *dic = &ip->i_d;

      return _xfs_dic2xflags(dic->di_flags) |
                        (XFS_CFORK_Q(dic) ? XFS_XFLAG_HASATTR : 0);
}

uint
xfs_dic2xflags(
      xfs_dinode_core_t *dic)
{
      return _xfs_dic2xflags(be16_to_cpu(dic->di_flags)) |
                        (XFS_CFORK_Q_DISK(dic) ? XFS_XFLAG_HASATTR : 0);
}

/*
 * Given a mount structure and an inode number, return a pointer
 * to a newly allocated in-core inode corresponding to the given
 * inode number.
 *
 * Initialize the inode's attributes and extent pointers if it
 * already has them (it will not if the inode has no links).
 */
int
xfs_iread(
      xfs_mount_t *mp,
      xfs_trans_t *tp,
      xfs_ino_t   ino,
      xfs_inode_t **ipp,
      xfs_daddr_t bno,
      uint        imap_flags)
{
      xfs_buf_t   *bp;
      xfs_dinode_t      *dip;
      xfs_inode_t *ip;
      int         error;

      ASSERT(xfs_inode_zone != NULL);

      ip = kmem_zone_zalloc(xfs_inode_zone, KM_SLEEP);
      ip->i_ino = ino;
      ip->i_mount = mp;
      atomic_set(&ip->i_iocount, 0);
      spin_lock_init(&ip->i_flags_lock);

      /*
       * Get pointer's to the on-disk inode and the buffer containing it.
       * If the inode number refers to a block outside the file system
       * then xfs_itobp() will return NULL.  In this case we should
       * return NULL as well.  Set i_blkno to 0 so that xfs_itobp() will
       * know that this is a new incore inode.
       */
      error = xfs_itobp(mp, tp, ip, &dip, &bp, bno, imap_flags);
      if (error) {
            kmem_zone_free(xfs_inode_zone, ip);
            return error;
      }

      /*
       * Initialize inode's trace buffers.
       * Do this before xfs_iformat in case it adds entries.
       */
#ifdef      XFS_VNODE_TRACE
      ip->i_trace = ktrace_alloc(VNODE_TRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_BMAP_TRACE
      ip->i_xtrace = ktrace_alloc(XFS_BMAP_KTRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_BMBT_TRACE
      ip->i_btrace = ktrace_alloc(XFS_BMBT_KTRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_RW_TRACE
      ip->i_rwtrace = ktrace_alloc(XFS_RW_KTRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_ILOCK_TRACE
      ip->i_lock_trace = ktrace_alloc(XFS_ILOCK_KTRACE_SIZE, KM_SLEEP);
#endif
#ifdef XFS_DIR2_TRACE
      ip->i_dir_trace = ktrace_alloc(XFS_DIR2_KTRACE_SIZE, KM_SLEEP);
#endif

      /*
       * If we got something that isn't an inode it means someone
       * (nfs or dmi) has a stale handle.
       */
      if (be16_to_cpu(dip->di_core.di_magic) != XFS_DINODE_MAGIC) {
            kmem_zone_free(xfs_inode_zone, ip);
            xfs_trans_brelse(tp, bp);
#ifdef DEBUG
            xfs_fs_cmn_err(CE_ALERT, mp, "xfs_iread: "
                        "dip->di_core.di_magic (0x%x) != "
                        "XFS_DINODE_MAGIC (0x%x)",
                        be16_to_cpu(dip->di_core.di_magic),
                        XFS_DINODE_MAGIC);
#endif /* DEBUG */
            return XFS_ERROR(EINVAL);
      }

      /*
       * If the on-disk inode is already linked to a directory
       * entry, copy all of the inode into the in-core inode.
       * xfs_iformat() handles copying in the inode format
       * specific information.
       * Otherwise, just get the truly permanent information.
       */
      if (dip->di_core.di_mode) {
            xfs_dinode_from_disk(&ip->i_d, &dip->di_core);
            error = xfs_iformat(ip, dip);
            if (error)  {
                  kmem_zone_free(xfs_inode_zone, ip);
                  xfs_trans_brelse(tp, bp);
#ifdef DEBUG
                  xfs_fs_cmn_err(CE_ALERT, mp, "xfs_iread: "
                              "xfs_iformat() returned error %d",
                              error);
#endif /* DEBUG */
                  return error;
            }
      } else {
            ip->i_d.di_magic = be16_to_cpu(dip->di_core.di_magic);
            ip->i_d.di_version = dip->di_core.di_version;
            ip->i_d.di_gen = be32_to_cpu(dip->di_core.di_gen);
            ip->i_d.di_flushiter = be16_to_cpu(dip->di_core.di_flushiter);
            /*
             * Make sure to pull in the mode here as well in
             * case the inode is released without being used.
             * This ensures that xfs_inactive() will see that
             * the inode is already free and not try to mess
             * with the uninitialized part of it.
             */
            ip->i_d.di_mode = 0;
            /*
             * Initialize the per-fork minima and maxima for a new
             * inode here.  xfs_iformat will do it for old inodes.
             */
            ip->i_df.if_ext_max =
                  XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
      }

      INIT_LIST_HEAD(&ip->i_reclaim);

      /*
       * The inode format changed when we moved the link count and
       * made it 32 bits long.  If this is an old format inode,
       * convert it in memory to look like a new one.  If it gets
       * flushed to disk we will convert back before flushing or
       * logging it.  We zero out the new projid field and the old link
       * count field.  We'll handle clearing the pad field (the remains
       * of the old uuid field) when we actually convert the inode to
       * the new format. We don't change the version number so that we
       * can distinguish this from a real new format inode.
       */
      if (ip->i_d.di_version == XFS_DINODE_VERSION_1) {
            ip->i_d.di_nlink = ip->i_d.di_onlink;
            ip->i_d.di_onlink = 0;
            ip->i_d.di_projid = 0;
      }

      ip->i_delayed_blks = 0;
      ip->i_size = ip->i_d.di_size;

      /*
       * Mark the buffer containing the inode as something to keep
       * around for a while.  This helps to keep recently accessed
       * meta-data in-core longer.
       */
       XFS_BUF_SET_REF(bp, XFS_INO_REF);

      /*
       * Use xfs_trans_brelse() to release the buffer containing the
       * on-disk inode, because it was acquired with xfs_trans_read_buf()
       * in xfs_itobp() above.  If tp is NULL, this is just a normal
       * brelse().  If we're within a transaction, then xfs_trans_brelse()
       * will only release the buffer if it is not dirty within the
       * transaction.  It will be OK to release the buffer in this case,
       * because inodes on disk are never destroyed and we will be
       * locking the new in-core inode before putting it in the hash
       * table where other processes can find it.  Thus we don't have
       * to worry about the inode being changed just because we released
       * the buffer.
       */
      xfs_trans_brelse(tp, bp);
      *ipp = ip;
      return 0;
}

/*
 * Read in extents from a btree-format inode.
 * Allocate and fill in if_extents.  Real work is done in xfs_bmap.c.
 */
int
xfs_iread_extents(
      xfs_trans_t *tp,
      xfs_inode_t *ip,
      int         whichfork)
{
      int         error;
      xfs_ifork_t *ifp;
      xfs_extnum_t      nextents;
      size_t            size;

      if (unlikely(XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE)) {
            XFS_ERROR_REPORT("xfs_iread_extents", XFS_ERRLEVEL_LOW,
                         ip->i_mount);
            return XFS_ERROR(EFSCORRUPTED);
      }
      nextents = XFS_IFORK_NEXTENTS(ip, whichfork);
      size = nextents * sizeof(xfs_bmbt_rec_t);
      ifp = XFS_IFORK_PTR(ip, whichfork);

      /*
       * We know that the size is valid (it's checked in iformat_btree)
       */
      ifp->if_lastex = NULLEXTNUM;
      ifp->if_bytes = ifp->if_real_bytes = 0;
      ifp->if_flags |= XFS_IFEXTENTS;
      xfs_iext_add(ifp, 0, nextents);
      error = xfs_bmap_read_extents(tp, ip, whichfork);
      if (error) {
            xfs_iext_destroy(ifp);
            ifp->if_flags &= ~XFS_IFEXTENTS;
            return error;
      }
      xfs_validate_extents(ifp, nextents, XFS_EXTFMT_INODE(ip));
      return 0;
}

/*
 * Allocate an inode on disk and return a copy of its in-core version.
 * The in-core inode is locked exclusively.  Set mode, nlink, and rdev
 * appropriately within the inode.  The uid and gid for the inode are
 * set according to the contents of the given cred structure.
 *
 * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
 * has a free inode available, call xfs_iget()
 * to obtain the in-core version of the allocated inode.  Finally,
 * fill in the inode and log its initial contents.  In this case,
 * ialloc_context would be set to NULL and call_again set to false.
 *
 * If xfs_dialloc() does not have an available inode,
 * it will replenish its supply by doing an allocation. Since we can
 * only do one allocation within a transaction without deadlocks, we
 * must commit the current transaction before returning the inode itself.
 * In this case, therefore, we will set call_again to true and return.
 * The caller should then commit the current transaction, start a new
 * transaction, and call xfs_ialloc() again to actually get the inode.
 *
 * To ensure that some other process does not grab the inode that
 * was allocated during the first call to xfs_ialloc(), this routine
 * also returns the [locked] bp pointing to the head of the freelist
 * as ialloc_context.  The caller should hold this buffer across
 * the commit and pass it back into this routine on the second call.
 *
 * If we are allocating quota inodes, we do not have a parent inode
 * to attach to or associate with (i.e. pip == NULL) because they
 * are not linked into the directory structure - they are attached
 * directly to the superblock - and so have no parent.
 */
int
xfs_ialloc(
      xfs_trans_t *tp,
      xfs_inode_t *pip,
      mode_t            mode,
      xfs_nlink_t nlink,
      xfs_dev_t   rdev,
      cred_t            *cr,
      xfs_prid_t  prid,
      int         okalloc,
      xfs_buf_t   **ialloc_context,
      boolean_t   *call_again,
      xfs_inode_t **ipp)
{
      xfs_ino_t   ino;
      xfs_inode_t *ip;
      bhv_vnode_t *vp;
      uint        flags;
      int         error;

      /*
       * Call the space management code to pick
       * the on-disk inode to be allocated.
       */
      error = xfs_dialloc(tp, pip ? pip->i_ino : 0, mode, okalloc,
                      ialloc_context, call_again, &ino);
      if (error != 0) {
            return error;
      }
      if (*call_again || ino == NULLFSINO) {
            *ipp = NULL;
            return 0;
      }
      ASSERT(*ialloc_context == NULL);

      /*
       * Get the in-core inode with the lock held exclusively.
       * This is because we're setting fields here we need
       * to prevent others from looking at until we're done.
       */
      error = xfs_trans_iget(tp->t_mountp, tp, ino,
                        XFS_IGET_CREATE, XFS_ILOCK_EXCL, &ip);
      if (error != 0) {
            return error;
      }
      ASSERT(ip != NULL);

      vp = XFS_ITOV(ip);
      ip->i_d.di_mode = (__uint16_t)mode;
      ip->i_d.di_onlink = 0;
      ip->i_d.di_nlink = nlink;
      ASSERT(ip->i_d.di_nlink == nlink);
      ip->i_d.di_uid = current_fsuid(cr);
      ip->i_d.di_gid = current_fsgid(cr);
      ip->i_d.di_projid = prid;
      memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));

      /*
       * If the superblock version is up to where we support new format
       * inodes and this is currently an old format inode, then change
       * the inode version number now.  This way we only do the conversion
       * here rather than here and in the flush/logging code.
       */
      if (XFS_SB_VERSION_HASNLINK(&tp->t_mountp->m_sb) &&
          ip->i_d.di_version == XFS_DINODE_VERSION_1) {
            ip->i_d.di_version = XFS_DINODE_VERSION_2;
            /*
             * We've already zeroed the old link count, the projid field,
             * and the pad field.
             */
      }

      /*
       * Project ids won't be stored on disk if we are using a version 1 inode.
       */
      if ((prid != 0) && (ip->i_d.di_version == XFS_DINODE_VERSION_1))
            xfs_bump_ino_vers2(tp, ip);

      if (pip && XFS_INHERIT_GID(pip)) {
            ip->i_d.di_gid = pip->i_d.di_gid;
            if ((pip->i_d.di_mode & S_ISGID) && (mode & S_IFMT) == S_IFDIR) {
                  ip->i_d.di_mode |= S_ISGID;
            }
      }

      /*
       * If the group ID of the new file does not match the effective group
       * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
       * (and only if the irix_sgid_inherit compatibility variable is set).
       */
      if ((irix_sgid_inherit) &&
          (ip->i_d.di_mode & S_ISGID) &&
          (!in_group_p((gid_t)ip->i_d.di_gid))) {
            ip->i_d.di_mode &= ~S_ISGID;
      }

      ip->i_d.di_size = 0;
      ip->i_size = 0;
      ip->i_d.di_nextents = 0;
      ASSERT(ip->i_d.di_nblocks == 0);
      xfs_ichgtime(ip, XFS_ICHGTIME_CHG|XFS_ICHGTIME_ACC|XFS_ICHGTIME_MOD);
      /*
       * di_gen will have been taken care of in xfs_iread.
       */
      ip->i_d.di_extsize = 0;
      ip->i_d.di_dmevmask = 0;
      ip->i_d.di_dmstate = 0;
      ip->i_d.di_flags = 0;
      flags = XFS_ILOG_CORE;
      switch (mode & S_IFMT) {
      case S_IFIFO:
      case S_IFCHR:
      case S_IFBLK:
      case S_IFSOCK:
            ip->i_d.di_format = XFS_DINODE_FMT_DEV;
            ip->i_df.if_u2.if_rdev = rdev;
            ip->i_df.if_flags = 0;
            flags |= XFS_ILOG_DEV;
            break;
      case S_IFREG:
            if (pip && xfs_inode_is_filestream(pip)) {
                  error = xfs_filestream_associate(pip, ip);
                  if (error < 0)
                        return -error;
                  if (!error)
                        xfs_iflags_set(ip, XFS_IFILESTREAM);
            }
            /* fall through */
      case S_IFDIR:
            if (pip && (pip->i_d.di_flags & XFS_DIFLAG_ANY)) {
                  uint  di_flags = 0;

                  if ((mode & S_IFMT) == S_IFDIR) {
                        if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT)
                              di_flags |= XFS_DIFLAG_RTINHERIT;
                        if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
                              di_flags |= XFS_DIFLAG_EXTSZINHERIT;
                              ip->i_d.di_extsize = pip->i_d.di_extsize;
                        }
                  } else if ((mode & S_IFMT) == S_IFREG) {
                        if (pip->i_d.di_flags & XFS_DIFLAG_RTINHERIT) {
                              di_flags |= XFS_DIFLAG_REALTIME;
                              ip->i_iocore.io_flags |= XFS_IOCORE_RT;
                        }
                        if (pip->i_d.di_flags & XFS_DIFLAG_EXTSZINHERIT) {
                              di_flags |= XFS_DIFLAG_EXTSIZE;
                              ip->i_d.di_extsize = pip->i_d.di_extsize;
                        }
                  }
                  if ((pip->i_d.di_flags & XFS_DIFLAG_NOATIME) &&
                      xfs_inherit_noatime)
                        di_flags |= XFS_DIFLAG_NOATIME;
                  if ((pip->i_d.di_flags & XFS_DIFLAG_NODUMP) &&
                      xfs_inherit_nodump)
                        di_flags |= XFS_DIFLAG_NODUMP;
                  if ((pip->i_d.di_flags & XFS_DIFLAG_SYNC) &&
                      xfs_inherit_sync)
                        di_flags |= XFS_DIFLAG_SYNC;
                  if ((pip->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) &&
                      xfs_inherit_nosymlinks)
                        di_flags |= XFS_DIFLAG_NOSYMLINKS;
                  if (pip->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
                        di_flags |= XFS_DIFLAG_PROJINHERIT;
                  if ((pip->i_d.di_flags & XFS_DIFLAG_NODEFRAG) &&
                      xfs_inherit_nodefrag)
                        di_flags |= XFS_DIFLAG_NODEFRAG;
                  if (pip->i_d.di_flags & XFS_DIFLAG_FILESTREAM)
                        di_flags |= XFS_DIFLAG_FILESTREAM;
                  ip->i_d.di_flags |= di_flags;
            }
            /* FALLTHROUGH */
      case S_IFLNK:
            ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
            ip->i_df.if_flags = XFS_IFEXTENTS;
            ip->i_df.if_bytes = ip->i_df.if_real_bytes = 0;
            ip->i_df.if_u1.if_extents = NULL;
            break;
      default:
            ASSERT(0);
      }
      /*
       * Attribute fork settings for new inode.
       */
      ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
      ip->i_d.di_anextents = 0;

      /*
       * Log the new values stuffed into the inode.
       */
      xfs_trans_log_inode(tp, ip, flags);

      /* now that we have an i_mode we can setup inode ops and unlock */
      xfs_initialize_vnode(tp->t_mountp, vp, ip);

      *ipp = ip;
      return 0;
}

/*
 * Check to make sure that there are no blocks allocated to the
 * file beyond the size of the file.  We don't check this for
 * files with fixed size extents or real time extents, but we
 * at least do it for regular files.
 */
#ifdef DEBUG
void
xfs_isize_check(
      xfs_mount_t *mp,
      xfs_inode_t *ip,
      xfs_fsize_t isize)
{
      xfs_fileoff_t     map_first;
      int         nimaps;
      xfs_bmbt_irec_t   imaps[2];

      if ((ip->i_d.di_mode & S_IFMT) != S_IFREG)
            return;

      if (ip->i_d.di_flags & (XFS_DIFLAG_REALTIME | XFS_DIFLAG_EXTSIZE))
            return;

      nimaps = 2;
      map_first = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
      /*
       * The filesystem could be shutting down, so bmapi may return
       * an error.
       */
      if (xfs_bmapi(NULL, ip, map_first,
                   (XFS_B_TO_FSB(mp,
                               (xfs_ufsize_t)XFS_MAXIOFFSET(mp)) -
                    map_first),
                   XFS_BMAPI_ENTIRE, NULL, 0, imaps, &nimaps,
                   NULL, NULL))
          return;
      ASSERT(nimaps == 1);
      ASSERT(imaps[0].br_startblock == HOLESTARTBLOCK);
}
#endif      /* DEBUG */

/*
 * Calculate the last possible buffered byte in a file.  This must
 * include data that was buffered beyond the EOF by the write code.
 * This also needs to deal with overflowing the xfs_fsize_t type
 * which can happen for sizes near the limit.
 *
 * We also need to take into account any blocks beyond the EOF.  It
 * may be the case that they were buffered by a write which failed.
 * In that case the pages will still be in memory, but the inode size
 * will never have been updated.
 */
xfs_fsize_t
xfs_file_last_byte(
      xfs_inode_t *ip)
{
      xfs_mount_t *mp;
      xfs_fsize_t last_byte;
      xfs_fileoff_t     last_block;
      xfs_fileoff_t     size_last_block;
      int         error;

      ASSERT(ismrlocked(&(ip->i_iolock), MR_UPDATE | MR_ACCESS));

      mp = ip->i_mount;
      /*
       * Only check for blocks beyond the EOF if the extents have
       * been read in.  This eliminates the need for the inode lock,
       * and it also saves us from looking when it really isn't
       * necessary.
       */
      if (ip->i_df.if_flags & XFS_IFEXTENTS) {
            error = xfs_bmap_last_offset(NULL, ip, &last_block,
                  XFS_DATA_FORK);
            if (error) {
                  last_block = 0;
            }
      } else {
            last_block = 0;
      }
      size_last_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)ip->i_size);
      last_block = XFS_FILEOFF_MAX(last_block, size_last_block);

      last_byte = XFS_FSB_TO_B(mp, last_block);
      if (last_byte < 0) {
            return XFS_MAXIOFFSET(mp);
      }
      last_byte += (1 << mp->m_writeio_log);
      if (last_byte < 0) {
            return XFS_MAXIOFFSET(mp);
      }
      return last_byte;
}

#if defined(XFS_RW_TRACE)
STATIC void
xfs_itrunc_trace(
      int         tag,
      xfs_inode_t *ip,
      int         flag,
      xfs_fsize_t new_size,
      xfs_off_t   toss_start,
      xfs_off_t   toss_finish)
{
      if (ip->i_rwtrace == NULL) {
            return;
      }

      ktrace_enter(ip->i_rwtrace,
                 (void*)((long)tag),
                 (void*)ip,
                 (void*)(unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff),
                 (void*)(unsigned long)(ip->i_d.di_size & 0xffffffff),
                 (void*)((long)flag),
                 (void*)(unsigned long)((new_size >> 32) & 0xffffffff),
                 (void*)(unsigned long)(new_size & 0xffffffff),
                 (void*)(unsigned long)((toss_start >> 32) & 0xffffffff),
                 (void*)(unsigned long)(toss_start & 0xffffffff),
                 (void*)(unsigned long)((toss_finish >> 32) & 0xffffffff),
                 (void*)(unsigned long)(toss_finish & 0xffffffff),
                 (void*)(unsigned long)current_cpu(),
                 (void*)(unsigned long)current_pid(),
                 (void*)NULL,
                 (void*)NULL,
                 (void*)NULL);
}
#else
#define     xfs_itrunc_trace(tag, ip, flag, new_size, toss_start, toss_finish)
#endif

/*
 * Start the truncation of the file to new_size.  The new size
 * must be smaller than the current size.  This routine will
 * clear the buffer and page caches of file data in the removed
 * range, and xfs_itruncate_finish() will remove the underlying
 * disk blocks.
 *
 * The inode must have its I/O lock locked EXCLUSIVELY, and it
 * must NOT have the inode lock held at all.  This is because we're
 * calling into the buffer/page cache code and we can't hold the
 * inode lock when we do so.
 *
 * We need to wait for any direct I/Os in flight to complete before we
 * proceed with the truncate. This is needed to prevent the extents
 * being read or written by the direct I/Os from being removed while the
 * I/O is in flight as there is no other method of synchronising
 * direct I/O with the truncate operation.  Also, because we hold
 * the IOLOCK in exclusive mode, we prevent new direct I/Os from being
 * started until the truncate completes and drops the lock. Essentially,
 * the vn_iowait() call forms an I/O barrier that provides strict ordering
 * between direct I/Os and the truncate operation.
 *
 * The flags parameter can have either the value XFS_ITRUNC_DEFINITE
 * or XFS_ITRUNC_MAYBE.  The XFS_ITRUNC_MAYBE value should be used
 * in the case that the caller is locking things out of order and
 * may not be able to call xfs_itruncate_finish() with the inode lock
 * held without dropping the I/O lock.  If the caller must drop the
 * I/O lock before calling xfs_itruncate_finish(), then xfs_itruncate_start()
 * must be called again with all the same restrictions as the initial
 * call.
 */
int
xfs_itruncate_start(
      xfs_inode_t *ip,
      uint        flags,
      xfs_fsize_t new_size)
{
      xfs_fsize_t last_byte;
      xfs_off_t   toss_start;
      xfs_mount_t *mp;
      bhv_vnode_t *vp;
      int         error = 0;

      ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE) != 0);
      ASSERT((new_size == 0) || (new_size <= ip->i_size));
      ASSERT((flags == XFS_ITRUNC_DEFINITE) ||
             (flags == XFS_ITRUNC_MAYBE));

      mp = ip->i_mount;
      vp = XFS_ITOV(ip);

      /* wait for the completion of any pending DIOs */
      if (new_size < ip->i_size)
            vn_iowait(ip);

      /*
       * Call toss_pages or flushinval_pages to get rid of pages
       * overlapping the region being removed.  We have to use
       * the less efficient flushinval_pages in the case that the
       * caller may not be able to finish the truncate without
       * dropping the inode's I/O lock.  Make sure
       * to catch any pages brought in by buffers overlapping
       * the EOF by searching out beyond the isize by our
       * block size. We round new_size up to a block boundary
       * so that we don't toss things on the same block as
       * new_size but before it.
       *
       * Before calling toss_page or flushinval_pages, make sure to
       * call remapf() over the same region if the file is mapped.
       * This frees up mapped file references to the pages in the
       * given range and for the flushinval_pages case it ensures
       * that we get the latest mapped changes flushed out.
       */
      toss_start = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
      toss_start = XFS_FSB_TO_B(mp, toss_start);
      if (toss_start < 0) {
            /*
             * The place to start tossing is beyond our maximum
             * file size, so there is no way that the data extended
             * out there.
             */
            return 0;
      }
      last_byte = xfs_file_last_byte(ip);
      xfs_itrunc_trace(XFS_ITRUNC_START, ip, flags, new_size, toss_start,
                   last_byte);
      if (last_byte > toss_start) {
            if (flags & XFS_ITRUNC_DEFINITE) {
                  xfs_tosspages(ip, toss_start,
                              -1, FI_REMAPF_LOCKED);
            } else {
                  error = xfs_flushinval_pages(ip, toss_start,
                              -1, FI_REMAPF_LOCKED);
            }
      }

#ifdef DEBUG
      if (new_size == 0) {
            ASSERT(VN_CACHED(vp) == 0);
      }
#endif
      return error;
}

/*
 * Shrink the file to the given new_size.  The new
 * size must be smaller than the current size.
 * This will free up the underlying blocks
 * in the removed range after a call to xfs_itruncate_start()
 * or xfs_atruncate_start().
 *
 * The transaction passed to this routine must have made
 * a permanent log reservation of at least XFS_ITRUNCATE_LOG_RES.
 * This routine may commit the given transaction and
 * start new ones, so make sure everything involved in
 * the transaction is tidy before calling here.
 * Some transaction will be returned to the caller to be
 * committed.  The incoming transaction must already include
 * the inode, and both inode locks must be held exclusively.
 * The inode must also be "held" within the transaction.  On
 * return the inode will be "held" within the returned transaction.
 * This routine does NOT require any disk space to be reserved
 * for it within the transaction.
 *
 * The fork parameter must be either xfs_attr_fork or xfs_data_fork,
 * and it indicates the fork which is to be truncated.  For the
 * attribute fork we only support truncation to size 0.
 *
 * We use the sync parameter to indicate whether or not the first
 * transaction we perform might have to be synchronous.  For the attr fork,
 * it needs to be so if the unlink of the inode is not yet known to be
 * permanent in the log.  This keeps us from freeing and reusing the
 * blocks of the attribute fork before the unlink of the inode becomes
 * permanent.
 *
 * For the data fork, we normally have to run synchronously if we're
 * being called out of the inactive path or we're being called
 * out of the create path where we're truncating an existing file.
 * Either way, the truncate needs to be sync so blocks don't reappear
 * in the file with altered data in case of a crash.  wsync filesystems
 * can run the first case async because anything that shrinks the inode
 * has to run sync so by the time we're called here from inactive, the
 * inode size is permanently set to 0.
 *
 * Calls from the truncate path always need to be sync unless we're
 * in a wsync filesystem and the file has already been unlinked.
 *
 * The caller is responsible for correctly setting the sync parameter.
 * It gets too hard for us to guess here which path we're being called
 * out of just based on inode state.
 */
int
xfs_itruncate_finish(
      xfs_trans_t **tp,
      xfs_inode_t *ip,
      xfs_fsize_t new_size,
      int         fork,
      int         sync)
{
      xfs_fsblock_t     first_block;
      xfs_fileoff_t     first_unmap_block;
      xfs_fileoff_t     last_block;
      xfs_filblks_t     unmap_len=0;
      xfs_mount_t *mp;
      xfs_trans_t *ntp;
      int         done;
      int         committed;
      xfs_bmap_free_t   free_list;
      int         error;

      ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE) != 0);
      ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
      ASSERT((new_size == 0) || (new_size <= ip->i_size));
      ASSERT(*tp != NULL);
      ASSERT((*tp)->t_flags & XFS_TRANS_PERM_LOG_RES);
      ASSERT(ip->i_transp == *tp);
      ASSERT(ip->i_itemp != NULL);
      ASSERT(ip->i_itemp->ili_flags & XFS_ILI_HOLD);


      ntp = *tp;
      mp = (ntp)->t_mountp;
      ASSERT(! XFS_NOT_DQATTACHED(mp, ip));

      /*
       * We only support truncating the entire attribute fork.
       */
      if (fork == XFS_ATTR_FORK) {
            new_size = 0LL;
      }
      first_unmap_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)new_size);
      xfs_itrunc_trace(XFS_ITRUNC_FINISH1, ip, 0, new_size, 0, 0);
      /*
       * The first thing we do is set the size to new_size permanently
       * on disk.  This way we don't have to worry about anyone ever
       * being able to look at the data being freed even in the face
       * of a crash.  What we're getting around here is the case where
       * we free a block, it is allocated to another file, it is written
       * to, and then we crash.  If the new data gets written to the
       * file but the log buffers containing the free and reallocation
       * don't, then we'd end up with garbage in the blocks being freed.
       * As long as we make the new_size permanent before actually
       * freeing any blocks it doesn't matter if they get writtten to.
       *
       * The callers must signal into us whether or not the size
       * setting here must be synchronous.  There are a few cases
       * where it doesn't have to be synchronous.  Those cases
       * occur if the file is unlinked and we know the unlink is
       * permanent or if the blocks being truncated are guaranteed
       * to be beyond the inode eof (regardless of the link count)
       * and the eof value is permanent.  Both of these cases occur
       * only on wsync-mounted filesystems.  In those cases, we're
       * guaranteed that no user will ever see the data in the blocks
       * that are being truncated so the truncate can run async.
       * In the free beyond eof case, the file may wind up with
       * more blocks allocated to it than it needs if we crash
       * and that won't get fixed until the next time the file
       * is re-opened and closed but that's ok as that shouldn't
       * be too many blocks.
       *
       * However, we can't just make all wsync xactions run async
       * because there's one call out of the create path that needs
       * to run sync where it's truncating an existing file to size
       * 0 whose size is > 0.
       *
       * It's probably possible to come up with a test in this
       * routine that would correctly distinguish all the above
       * cases from the values of the function parameters and the
       * inode state but for sanity's sake, I've decided to let the
       * layers above just tell us.  It's simpler to correctly figure
       * out in the layer above exactly under what conditions we
       * can run async and I think it's easier for others read and
       * follow the logic in case something has to be changed.
       * cscope is your friend -- rcc.
       *
       * The attribute fork is much simpler.
       *
       * For the attribute fork we allow the caller to tell us whether
       * the unlink of the inode that led to this call is yet permanent
       * in the on disk log.  If it is not and we will be freeing extents
       * in this inode then we make the first transaction synchronous
       * to make sure that the unlink is permanent by the time we free
       * the blocks.
       */
      if (fork == XFS_DATA_FORK) {
            if (ip->i_d.di_nextents > 0) {
                  /*
                   * If we are not changing the file size then do
                   * not update the on-disk file size - we may be
                   * called from xfs_inactive_free_eofblocks().  If we
                   * update the on-disk file size and then the system
                   * crashes before the contents of the file are
                   * flushed to disk then the files may be full of
                   * holes (ie NULL files bug).
                   */
                  if (ip->i_size != new_size) {
                        ip->i_d.di_size = new_size;
                        ip->i_size = new_size;
                        xfs_trans_log_inode(ntp, ip, XFS_ILOG_CORE);
                  }
            }
      } else if (sync) {
            ASSERT(!(mp->m_flags & XFS_MOUNT_WSYNC));
            if (ip->i_d.di_anextents > 0)
                  xfs_trans_set_sync(ntp);
      }
      ASSERT(fork == XFS_DATA_FORK ||
            (fork == XFS_ATTR_FORK &&
                  ((sync && !(mp->m_flags & XFS_MOUNT_WSYNC)) ||
                   (sync == 0 && (mp->m_flags & XFS_MOUNT_WSYNC)))));

      /*
       * Since it is possible for space to become allocated beyond
       * the end of the file (in a crash where the space is allocated
       * but the inode size is not yet updated), simply remove any
       * blocks which show up between the new EOF and the maximum
       * possible file size.  If the first block to be removed is
       * beyond the maximum file size (ie it is the same as last_block),
       * then there is nothing to do.
       */
      last_block = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
      ASSERT(first_unmap_block <= last_block);
      done = 0;
      if (last_block == first_unmap_block) {
            done = 1;
      } else {
            unmap_len = last_block - first_unmap_block + 1;
      }
      while (!done) {
            /*
             * Free up up to XFS_ITRUNC_MAX_EXTENTS.  xfs_bunmapi()
             * will tell us whether it freed the entire range or
             * not.  If this is a synchronous mount (wsync),
             * then we can tell bunmapi to keep all the
             * transactions asynchronous since the unlink
             * transaction that made this inode inactive has
             * already hit the disk.  There's no danger of
             * the freed blocks being reused, there being a
             * crash, and the reused blocks suddenly reappearing
             * in this file with garbage in them once recovery
             * runs.
             */
            XFS_BMAP_INIT(&free_list, &first_block);
            error = XFS_BUNMAPI(mp, ntp, &ip->i_iocore,
                            first_unmap_block, unmap_len,
                            XFS_BMAPI_AFLAG(fork) |
                              (sync ? 0 : XFS_BMAPI_ASYNC),
                            XFS_ITRUNC_MAX_EXTENTS,
                            &first_block, &free_list,
                            NULL, &done);
            if (error) {
                  /*
                   * If the bunmapi call encounters an error,
                   * return to the caller where the transaction
                   * can be properly aborted.  We just need to
                   * make sure we're not holding any resources
                   * that we were not when we came in.
                   */
                  xfs_bmap_cancel(&free_list);
                  return error;
            }

            /*
             * Duplicate the transaction that has the permanent
             * reservation and commit the old transaction.
             */
            error = xfs_bmap_finish(tp, &free_list, &committed);
            ntp = *tp;
            if (error) {
                  /*
                   * If the bmap finish call encounters an error,
                   * return to the caller where the transaction
                   * can be properly aborted.  We just need to
                   * make sure we're not holding any resources
                   * that we were not when we came in.
                   *
                   * Aborting from this point might lose some
                   * blocks in the file system, but oh well.
                   */
                  xfs_bmap_cancel(&free_list);
                  if (committed) {
                        /*
                         * If the passed in transaction committed
                         * in xfs_bmap_finish(), then we want to
                         * add the inode to this one before returning.
                         * This keeps things simple for the higher
                         * level code, because it always knows that
                         * the inode is locked and held in the
                         * transaction that returns to it whether
                         * errors occur or not.  We don't mark the
                         * inode dirty so that this transaction can
                         * be easily aborted if possible.
                         */
                        xfs_trans_ijoin(ntp, ip,
                              XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
                        xfs_trans_ihold(ntp, ip);
                  }
                  return error;
            }

            if (committed) {
                  /*
                   * The first xact was committed,
                   * so add the inode to the new one.
                   * Mark it dirty so it will be logged
                   * and moved forward in the log as
                   * part of every commit.
                   */
                  xfs_trans_ijoin(ntp, ip,
                              XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
                  xfs_trans_ihold(ntp, ip);
                  xfs_trans_log_inode(ntp, ip, XFS_ILOG_CORE);
            }
            ntp = xfs_trans_dup(ntp);
            (void) xfs_trans_commit(*tp, 0);
            *tp = ntp;
            error = xfs_trans_reserve(ntp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
                                XFS_TRANS_PERM_LOG_RES,
                                XFS_ITRUNCATE_LOG_COUNT);
            /*
             * Add the inode being truncated to the next chained
             * transaction.
             */
            xfs_trans_ijoin(ntp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
            xfs_trans_ihold(ntp, ip);
            if (error)
                  return (error);
      }
      /*
       * Only update the size in the case of the data fork, but
       * always re-log the inode so that our permanent transaction
       * can keep on rolling it forward in the log.
       */
      if (fork == XFS_DATA_FORK) {
            xfs_isize_check(mp, ip, new_size);
            /*
             * If we are not changing the file size then do
             * not update the on-disk file size - we may be
             * called from xfs_inactive_free_eofblocks().  If we
             * update the on-disk file size and then the system
             * crashes before the contents of the file are
             * flushed to disk then the files may be full of
             * holes (ie NULL files bug).
             */
            if (ip->i_size != new_size) {
                  ip->i_d.di_size = new_size;
                  ip->i_size = new_size;
            }
      }
      xfs_trans_log_inode(ntp, ip, XFS_ILOG_CORE);
      ASSERT((new_size != 0) ||
             (fork == XFS_ATTR_FORK) ||
             (ip->i_delayed_blks == 0));
      ASSERT((new_size != 0) ||
             (fork == XFS_ATTR_FORK) ||
             (ip->i_d.di_nextents == 0));
      xfs_itrunc_trace(XFS_ITRUNC_FINISH2, ip, 0, new_size, 0, 0);
      return 0;
}


/*
 * xfs_igrow_start
 *
 * Do the first part of growing a file: zero any data in the last
 * block that is beyond the old EOF.  We need to do this before
 * the inode is joined to the transaction to modify the i_size.
 * That way we can drop the inode lock and call into the buffer
 * cache to get the buffer mapping the EOF.
 */
int
xfs_igrow_start(
      xfs_inode_t *ip,
      xfs_fsize_t new_size,
      cred_t            *credp)
{
      int         error;

      ASSERT(ismrlocked(&(ip->i_lock), MR_UPDATE) != 0);
      ASSERT(ismrlocked(&(ip->i_iolock), MR_UPDATE) != 0);
      ASSERT(new_size > ip->i_size);

      /*
       * Zero any pages that may have been created by
       * xfs_write_file() beyond the end of the file
       * and any blocks between the old and new file sizes.
       */
      error = xfs_zero_eof(XFS_ITOV(ip), &ip->i_iocore, new_size,
                       ip->i_size);
      return error;
}

/*
 * xfs_igrow_finish
 *
 * This routine is called to extend the size of a file.
 * The inode must have both the iolock and the ilock locked
 * for update and it must be a part of the current transaction.
 * The xfs_igrow_start() function must have been called previously.
 * If the change_flag is not zero, the inode change timestamp will
 * be updated.
 */
void
xfs_igrow_finish(
      xfs_trans_t *tp,
      xfs_inode_t *ip,
      xfs_fsize_t new_size,
      int         change_flag)
{
      ASSERT(ismrlocked(&(ip->i_lock), MR_UPDATE) != 0);
      ASSERT(ismrlocked(&(ip->i_iolock), MR_UPDATE) != 0);
      ASSERT(ip->i_transp == tp);
      ASSERT(new_size > ip->i_size);

      /*
       * Update the file size.  Update the inode change timestamp
       * if change_flag set.
       */
      ip->i_d.di_size = new_size;
      ip->i_size = new_size;
      if (change_flag)
            xfs_ichgtime(ip, XFS_ICHGTIME_CHG);
      xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

}


/*
 * This is called when the inode's link count goes to 0.
 * We place the on-disk inode on a list in the AGI.  It
 * will be pulled from this list when the inode is freed.
 */
int
xfs_iunlink(
      xfs_trans_t *tp,
      xfs_inode_t *ip)
{
      xfs_mount_t *mp;
      xfs_agi_t   *agi;
      xfs_dinode_t      *dip;
      xfs_buf_t   *agibp;
      xfs_buf_t   *ibp;
      xfs_agnumber_t    agno;
      xfs_daddr_t agdaddr;
      xfs_agino_t agino;
      short       bucket_index;
      int         offset;
      int         error;
      int         agi_ok;

      ASSERT(ip->i_d.di_nlink == 0);
      ASSERT(ip->i_d.di_mode != 0);
      ASSERT(ip->i_transp == tp);

      mp = tp->t_mountp;

      agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
      agdaddr = XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp));

      /*
       * Get the agi buffer first.  It ensures lock ordering
       * on the list.
       */
      error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, agdaddr,
                           XFS_FSS_TO_BB(mp, 1), 0, &agibp);
      if (error)
            return error;

      /*
       * Validate the magic number of the agi block.
       */
      agi = XFS_BUF_TO_AGI(agibp);
      agi_ok =
            be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC &&
            XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum));
      if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IUNLINK,
                  XFS_RANDOM_IUNLINK))) {
            XFS_CORRUPTION_ERROR("xfs_iunlink", XFS_ERRLEVEL_LOW, mp, agi);
            xfs_trans_brelse(tp, agibp);
            return XFS_ERROR(EFSCORRUPTED);
      }
      /*
       * Get the index into the agi hash table for the
       * list this inode will go on.
       */
      agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
      ASSERT(agino != 0);
      bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
      ASSERT(agi->agi_unlinked[bucket_index]);
      ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != agino);

      error = xfs_itobp(mp, tp, ip, &dip, &ibp, 0, 0);
      if (error)
            return error;

      /*
       * Clear the on-disk di_nlink. This is to prevent xfs_bulkstat
       * from picking up this inode when it is reclaimed (its incore state
       * initialzed but not flushed to disk yet). The in-core di_nlink is
       * already cleared in xfs_droplink() and a corresponding transaction
       * logged. The hack here just synchronizes the in-core to on-disk
       * di_nlink value in advance before the actual inode sync to disk.
       * This is OK because the inode is already unlinked and would never
       * change its di_nlink again for this inode generation.
       * This is a temporary hack that would require a proper fix
       * in the future.
       */
      dip->di_core.di_nlink = 0;

      if (be32_to_cpu(agi->agi_unlinked[bucket_index]) != NULLAGINO) {
            /*
             * There is already another inode in the bucket we need
             * to add ourselves to.  Add us at the front of the list.
             * Here we put the head pointer into our next pointer,
             * and then we fall through to point the head at us.
             */
            ASSERT(be32_to_cpu(dip->di_next_unlinked) == NULLAGINO);
            /* both on-disk, don't endian flip twice */
            dip->di_next_unlinked = agi->agi_unlinked[bucket_index];
            offset = ip->i_boffset +
                  offsetof(xfs_dinode_t, di_next_unlinked);
            xfs_trans_inode_buf(tp, ibp);
            xfs_trans_log_buf(tp, ibp, offset,
                          (offset + sizeof(xfs_agino_t) - 1));
            xfs_inobp_check(mp, ibp);
      }

      /*
       * Point the bucket head pointer at the inode being inserted.
       */
      ASSERT(agino != 0);
      agi->agi_unlinked[bucket_index] = cpu_to_be32(agino);
      offset = offsetof(xfs_agi_t, agi_unlinked) +
            (sizeof(xfs_agino_t) * bucket_index);
      xfs_trans_log_buf(tp, agibp, offset,
                    (offset + sizeof(xfs_agino_t) - 1));
      return 0;
}

/*
 * Pull the on-disk inode from the AGI unlinked list.
 */
STATIC int
xfs_iunlink_remove(
      xfs_trans_t *tp,
      xfs_inode_t *ip)
{
      xfs_ino_t   next_ino;
      xfs_mount_t *mp;
      xfs_agi_t   *agi;
      xfs_dinode_t      *dip;
      xfs_buf_t   *agibp;
      xfs_buf_t   *ibp;
      xfs_agnumber_t    agno;
      xfs_daddr_t agdaddr;
      xfs_agino_t agino;
      xfs_agino_t next_agino;
      xfs_buf_t   *last_ibp;
      xfs_dinode_t      *last_dip = NULL;
      short       bucket_index;
      int         offset, last_offset = 0;
      int         error;
      int         agi_ok;

      /*
       * First pull the on-disk inode from the AGI unlinked list.
       */
      mp = tp->t_mountp;

      agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
      agdaddr = XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp));

      /*
       * Get the agi buffer first.  It ensures lock ordering
       * on the list.
       */
      error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, agdaddr,
                           XFS_FSS_TO_BB(mp, 1), 0, &agibp);
      if (error) {
            cmn_err(CE_WARN,
                  "xfs_iunlink_remove: xfs_trans_read_buf()  returned an error %d on %s.  Returning error.",
                  error, mp->m_fsname);
            return error;
      }
      /*
       * Validate the magic number of the agi block.
       */
      agi = XFS_BUF_TO_AGI(agibp);
      agi_ok =
            be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC &&
            XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum));
      if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IUNLINK_REMOVE,
                  XFS_RANDOM_IUNLINK_REMOVE))) {
            XFS_CORRUPTION_ERROR("xfs_iunlink_remove", XFS_ERRLEVEL_LOW,
                             mp, agi);
            xfs_trans_brelse(tp, agibp);
            cmn_err(CE_WARN,
                  "xfs_iunlink_remove: XFS_TEST_ERROR()  returned an error on %s.  Returning EFSCORRUPTED.",
                   mp->m_fsname);
            return XFS_ERROR(EFSCORRUPTED);
      }
      /*
       * Get the index into the agi hash table for the
       * list this inode will go on.
       */
      agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
      ASSERT(agino != 0);
      bucket_index = agino % XFS_AGI_UNLINKED_BUCKETS;
      ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != NULLAGINO);
      ASSERT(agi->agi_unlinked[bucket_index]);

      if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) {
            /*
             * We're at the head of the list.  Get the inode's
             * on-disk buffer to see if there is anyone after us
             * on the list.  Only modify our next pointer if it
             * is not already NULLAGINO.  This saves us the overhead
             * of dealing with the buffer when there is no need to
             * change it.
             */
            error = xfs_itobp(mp, tp, ip, &dip, &ibp, 0, 0);
            if (error) {
                  cmn_err(CE_WARN,
                        "xfs_iunlink_remove: xfs_itobp()  returned an error %d on %s.  Returning error.",
                        error, mp->m_fsname);
                  return error;
            }
            next_agino = be32_to_cpu(dip->di_next_unlinked);
            ASSERT(next_agino != 0);
            if (next_agino != NULLAGINO) {
                  dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
                  offset = ip->i_boffset +
                        offsetof(xfs_dinode_t, di_next_unlinked);
                  xfs_trans_inode_buf(tp, ibp);
                  xfs_trans_log_buf(tp, ibp, offset,
                                (offset + sizeof(xfs_agino_t) - 1));
                  xfs_inobp_check(mp, ibp);
            } else {
                  xfs_trans_brelse(tp, ibp);
            }
            /*
             * Point the bucket head pointer at the next inode.
             */
            ASSERT(next_agino != 0);
            ASSERT(next_agino != agino);
            agi->agi_unlinked[bucket_index] = cpu_to_be32(next_agino);
            offset = offsetof(xfs_agi_t, agi_unlinked) +
                  (sizeof(xfs_agino_t) * bucket_index);
            xfs_trans_log_buf(tp, agibp, offset,
                          (offset + sizeof(xfs_agino_t) - 1));
      } else {
            /*
             * We need to search the list for the inode being freed.
             */
            next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]);
            last_ibp = NULL;
            while (next_agino != agino) {
                  /*
                   * If the last inode wasn't the one pointing to
                   * us, then release its buffer since we're not
                   * going to do anything with it.
                   */
                  if (last_ibp != NULL) {
                        xfs_trans_brelse(tp, last_ibp);
                  }
                  next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);
                  error = xfs_inotobp(mp, tp, next_ino, &last_dip,
                                  &last_ibp, &last_offset);
                  if (error) {
                        cmn_err(CE_WARN,
                  "xfs_iunlink_remove: xfs_inotobp()  returned an error %d on %s.  Returning error.",
                              error, mp->m_fsname);
                        return error;
                  }
                  next_agino = be32_to_cpu(last_dip->di_next_unlinked);
                  ASSERT(next_agino != NULLAGINO);
                  ASSERT(next_agino != 0);
            }
            /*
             * Now last_ibp points to the buffer previous to us on
             * the unlinked list.  Pull us from the list.
             */
            error = xfs_itobp(mp, tp, ip, &dip, &ibp, 0, 0);
            if (error) {
                  cmn_err(CE_WARN,
                        "xfs_iunlink_remove: xfs_itobp()  returned an error %d on %s.  Returning error.",
                        error, mp->m_fsname);
                  return error;
            }
            next_agino = be32_to_cpu(dip->di_next_unlinked);
            ASSERT(next_agino != 0);
            ASSERT(next_agino != agino);
            if (next_agino != NULLAGINO) {
                  dip->di_next_unlinked = cpu_to_be32(NULLAGINO);
                  offset = ip->i_boffset +
                        offsetof(xfs_dinode_t, di_next_unlinked);
                  xfs_trans_inode_buf(tp, ibp);
                  xfs_trans_log_buf(tp, ibp, offset,
                                (offset + sizeof(xfs_agino_t) - 1));
                  xfs_inobp_check(mp, ibp);
            } else {
                  xfs_trans_brelse(tp, ibp);
            }
            /*
             * Point the previous inode on the list to the next inode.
             */
            last_dip->di_next_unlinked = cpu_to_be32(next_agino);
            ASSERT(next_agino != 0);
            offset = last_offset + offsetof(xfs_dinode_t, di_next_unlinked);
            xfs_trans_inode_buf(tp, last_ibp);
            xfs_trans_log_buf(tp, last_ibp, offset,
                          (offset + sizeof(xfs_agino_t) - 1));
            xfs_inobp_check(mp, last_ibp);
      }
      return 0;
}

STATIC_INLINE int xfs_inode_clean(xfs_inode_t *ip)
{
      return (((ip->i_itemp == NULL) ||
            !(ip->i_itemp->ili_format.ilf_fields & XFS_ILOG_ALL)) &&
            (ip->i_update_core == 0));
}

STATIC void
xfs_ifree_cluster(
      xfs_inode_t *free_ip,
      xfs_trans_t *tp,
      xfs_ino_t   inum)
{
      xfs_mount_t       *mp = free_ip->i_mount;
      int               blks_per_cluster;
      int               nbufs;
      int               ninodes;
      int               i, j, found, pre_flushed;
      xfs_daddr_t       blkno;
      xfs_buf_t         *bp;
      xfs_inode_t       *ip, **ip_found;
      xfs_inode_log_item_t    *iip;
      xfs_log_item_t          *lip;
      xfs_perag_t       *pag = xfs_get_perag(mp, inum);
      SPLDECL(s);

      if (mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(mp)) {
            blks_per_cluster = 1;
            ninodes = mp->m_sb.sb_inopblock;
            nbufs = XFS_IALLOC_BLOCKS(mp);
      } else {
            blks_per_cluster = XFS_INODE_CLUSTER_SIZE(mp) /
                              mp->m_sb.sb_blocksize;
            ninodes = blks_per_cluster * mp->m_sb.sb_inopblock;
            nbufs = XFS_IALLOC_BLOCKS(mp) / blks_per_cluster;
      }

      ip_found = kmem_alloc(ninodes * sizeof(xfs_inode_t *), KM_NOFS);

      for (j = 0; j < nbufs; j++, inum += ninodes) {
            blkno = XFS_AGB_TO_DADDR(mp, XFS_INO_TO_AGNO(mp, inum),
                               XFS_INO_TO_AGBNO(mp, inum));


            /*
             * Look for each inode in memory and attempt to lock it,
             * we can be racing with flush and tail pushing here.
             * any inode we get the locks on, add to an array of
             * inode items to process later.
             *
             * The get the buffer lock, we could beat a flush
             * or tail pushing thread to the lock here, in which
             * case they will go looking for the inode buffer
             * and fail, we need some other form of interlock
             * here.
             */
            found = 0;
            for (i = 0; i < ninodes; i++) {
                  read_lock(&pag->pag_ici_lock);
                  ip = radix_tree_lookup(&pag->pag_ici_root,
                              XFS_INO_TO_AGINO(mp, (inum + i)));

                  /* Inode not in memory or we found it already,
                   * nothing to do
                   */
                  if (!ip || xfs_iflags_test(ip, XFS_ISTALE)) {
                        read_unlock(&pag->pag_ici_lock);
                        continue;
                  }

                  if (xfs_inode_clean(ip)) {
                        read_unlock(&pag->pag_ici_lock);
                        continue;
                  }

                  /* If we can get the locks then add it to the
                   * list, otherwise by the time we get the bp lock
                   * below it will already be attached to the
                   * inode buffer.
                   */

                  /* This inode will already be locked - by us, lets
                   * keep it that way.
                   */

                  if (ip == free_ip) {
                        if (xfs_iflock_nowait(ip)) {
                              xfs_iflags_set(ip, XFS_ISTALE);
                              if (xfs_inode_clean(ip)) {
                                    xfs_ifunlock(ip);
                              } else {
                                    ip_found[found++] = ip;
                              }
                        }
                        read_unlock(&pag->pag_ici_lock);
                        continue;
                  }

                  if (xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
                        if (xfs_iflock_nowait(ip)) {
                              xfs_iflags_set(ip, XFS_ISTALE);

                              if (xfs_inode_clean(ip)) {
                                    xfs_ifunlock(ip);
                                    xfs_iunlock(ip, XFS_ILOCK_EXCL);
                              } else {
                                    ip_found[found++] = ip;
                              }
                        } else {
                              xfs_iunlock(ip, XFS_ILOCK_EXCL);
                        }
                  }
                  read_unlock(&pag->pag_ici_lock);
            }

            bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno, 
                              mp->m_bsize * blks_per_cluster,
                              XFS_BUF_LOCK);

            pre_flushed = 0;
            lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
            while (lip) {
                  if (lip->li_type == XFS_LI_INODE) {
                        iip = (xfs_inode_log_item_t *)lip;
                        ASSERT(iip->ili_logged == 1);
                        lip->li_cb = (void(*)(xfs_buf_t*,xfs_log_item_t*)) xfs_istale_done;
                        AIL_LOCK(mp,s);
                        iip->ili_flush_lsn = iip->ili_item.li_lsn;
                        AIL_UNLOCK(mp, s);
                        xfs_iflags_set(iip->ili_inode, XFS_ISTALE);
                        pre_flushed++;
                  }
                  lip = lip->li_bio_list;
            }

            for (i = 0; i < found; i++) {
                  ip = ip_found[i];
                  iip = ip->i_itemp;

                  if (!iip) {
                        ip->i_update_core = 0;
                        xfs_ifunlock(ip);
                        xfs_iunlock(ip, XFS_ILOCK_EXCL);
                        continue;
                  }

                  iip->ili_last_fields = iip->ili_format.ilf_fields;
                  iip->ili_format.ilf_fields = 0;
                  iip->ili_logged = 1;
                  AIL_LOCK(mp,s);
                  iip->ili_flush_lsn = iip->ili_item.li_lsn;
                  AIL_UNLOCK(mp, s);

                  xfs_buf_attach_iodone(bp,
                        (void(*)(xfs_buf_t*,xfs_log_item_t*))
                        xfs_istale_done, (xfs_log_item_t *)iip);
                  if (ip != free_ip) {
                        xfs_iunlock(ip, XFS_ILOCK_EXCL);
                  }
            }

            if (found || pre_flushed)
                  xfs_trans_stale_inode_buf(tp, bp);
            xfs_trans_binval(tp, bp);
      }

      kmem_free(ip_found, ninodes * sizeof(xfs_inode_t *));
      xfs_put_perag(mp, pag);
}

/*
 * This is called to return an inode to the inode free list.
 * The inode should already be truncated to 0 length and have
 * no pages associated with it.  This routine also assumes that
 * the inode is already a part of the transaction.
 *
 * The on-disk copy of the inode will have been added to the list
 * of unlinked inodes in the AGI. We need to remove the inode from
 * that list atomically with respect to freeing it here.
 */
int
xfs_ifree(
      xfs_trans_t *tp,
      xfs_inode_t *ip,
      xfs_bmap_free_t   *flist)
{
      int               error;
      int               delete;
      xfs_ino_t         first_ino;

      ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
      ASSERT(ip->i_transp == tp);
      ASSERT(ip->i_d.di_nlink == 0);
      ASSERT(ip->i_d.di_nextents == 0);
      ASSERT(ip->i_d.di_anextents == 0);
      ASSERT((ip->i_d.di_size == 0 && ip->i_size == 0) ||
             ((ip->i_d.di_mode & S_IFMT) != S_IFREG));
      ASSERT(ip->i_d.di_nblocks == 0);

      /*
       * Pull the on-disk inode from the AGI unlinked list.
       */
      error = xfs_iunlink_remove(tp, ip);
      if (error != 0) {
            return error;
      }

      error = xfs_difree(tp, ip->i_ino, flist, &delete, &first_ino);
      if (error != 0) {
            return error;
      }
      ip->i_d.di_mode = 0;          /* mark incore inode as free */
      ip->i_d.di_flags = 0;
      ip->i_d.di_dmevmask = 0;
      ip->i_d.di_forkoff = 0;       /* mark the attr fork not in use */
      ip->i_df.if_ext_max =
            XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
      ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
      ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
      /*
       * Bump the generation count so no one will be confused
       * by reincarnations of this inode.
       */
      ip->i_d.di_gen++;
      xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

      if (delete) {
            xfs_ifree_cluster(ip, tp, first_ino);
      }

      return 0;
}

/*
 * Reallocate the space for if_broot based on the number of records
 * being added or deleted as indicated in rec_diff.  Move the records
 * and pointers in if_broot to fit the new size.  When shrinking this
 * will eliminate holes between the records and pointers created by
 * the caller.  When growing this will create holes to be filled in
 * by the caller.
 *
 * The caller must not request to add more records than would fit in
 * the on-disk inode root.  If the if_broot is currently NULL, then
 * if we adding records one will be allocated.  The caller must also
 * not request that the number of records go below zero, although
 * it can go to zero.
 *
 * ip -- the inode whose if_broot area is changing
 * ext_diff -- the change in the number of records, positive or negative,
 *     requested for the if_broot array.
 */
void
xfs_iroot_realloc(
      xfs_inode_t       *ip,
      int               rec_diff,
      int               whichfork)
{
      int               cur_max;
      xfs_ifork_t       *ifp;
      xfs_bmbt_block_t  *new_broot;
      int               new_max;
      size_t                  new_size;
      char              *np;
      char              *op;

      /*
       * Handle the degenerate case quietly.
       */
      if (rec_diff == 0) {
            return;
      }

      ifp = XFS_IFORK_PTR(ip, whichfork);
      if (rec_diff > 0) {
            /*
             * If there wasn't any memory allocated before, just
             * allocate it now and get out.
             */
            if (ifp->if_broot_bytes == 0) {
                  new_size = (size_t)XFS_BMAP_BROOT_SPACE_CALC(rec_diff);
                  ifp->if_broot = (xfs_bmbt_block_t*)kmem_alloc(new_size,
                                                     KM_SLEEP);
                  ifp->if_broot_bytes = (int)new_size;
                  return;
            }

            /*
             * If there is already an existing if_broot, then we need
             * to realloc() it and shift the pointers to their new
             * location.  The records don't change location because
             * they are kept butted up against the btree block header.
             */
            cur_max = XFS_BMAP_BROOT_MAXRECS(ifp->if_broot_bytes);
            new_max = cur_max + rec_diff;
            new_size = (size_t)XFS_BMAP_BROOT_SPACE_CALC(new_max);
            ifp->if_broot = (xfs_bmbt_block_t *)
              kmem_realloc(ifp->if_broot,
                        new_size,
                        (size_t)XFS_BMAP_BROOT_SPACE_CALC(cur_max), /* old size */
                        KM_SLEEP);
            op = (char *)XFS_BMAP_BROOT_PTR_ADDR(ifp->if_broot, 1,
                                          ifp->if_broot_bytes);
            np = (char *)XFS_BMAP_BROOT_PTR_ADDR(ifp->if_broot, 1,
                                          (int)new_size);
            ifp->if_broot_bytes = (int)new_size;
            ASSERT(ifp->if_broot_bytes <=
                  XFS_IFORK_SIZE(ip, whichfork) + XFS_BROOT_SIZE_ADJ);
            memmove(np, op, cur_max * (uint)sizeof(xfs_dfsbno_t));
            return;
      }

      /*
       * rec_diff is less than 0.  In this case, we are shrinking the
       * if_broot buffer.  It must already exist.  If we go to zero
       * records, just get rid of the root and clear the status bit.
       */
      ASSERT((ifp->if_broot != NULL) && (ifp->if_broot_bytes > 0));
      cur_max = XFS_BMAP_BROOT_MAXRECS(ifp->if_broot_bytes);
      new_max = cur_max + rec_diff;
      ASSERT(new_max >= 0);
      if (new_max > 0)
            new_size = (size_t)XFS_BMAP_BROOT_SPACE_CALC(new_max);
      else
            new_size = 0;
      if (new_size > 0) {
            new_broot = (xfs_bmbt_block_t *)kmem_alloc(new_size, KM_SLEEP);
            /*
             * First copy over the btree block header.
             */
            memcpy(new_broot, ifp->if_broot, sizeof(xfs_bmbt_block_t));
      } else {
            new_broot = NULL;
            ifp->if_flags &= ~XFS_IFBROOT;
      }

      /*
       * Only copy the records and pointers if there are any.
       */
      if (new_max > 0) {
            /*
             * First copy the records.
             */
            op = (char *)XFS_BMAP_BROOT_REC_ADDR(ifp->if_broot, 1,
                                         ifp->if_broot_bytes);
            np = (char *)XFS_BMAP_BROOT_REC_ADDR(new_broot, 1,
                                         (int)new_size);
            memcpy(np, op, new_max * (uint)sizeof(xfs_bmbt_rec_t));

            /*
             * Then copy the pointers.
             */
            op = (char *)XFS_BMAP_BROOT_PTR_ADDR(ifp->if_broot, 1,
                                         ifp->if_broot_bytes);
            np = (char *)XFS_BMAP_BROOT_PTR_ADDR(new_broot, 1,
                                         (int)new_size);
            memcpy(np, op, new_max * (uint)sizeof(xfs_dfsbno_t));
      }
      kmem_free(ifp->if_broot, ifp->if_broot_bytes);
      ifp->if_broot = new_broot;
      ifp->if_broot_bytes = (int)new_size;
      ASSERT(ifp->if_broot_bytes <=
            XFS_IFORK_SIZE(ip, whichfork) + XFS_BROOT_SIZE_ADJ);
      return;
}


/*
 * This is called when the amount of space needed for if_data
 * is increased or decreased.  The change in size is indicated by
 * the number of bytes that need to be added or deleted in the
 * byte_diff parameter.
 *
 * If the amount of space needed has decreased below the size of the
 * inline buffer, then switch to using the inline buffer.  Otherwise,
 * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
 * to what is needed.
 *
 * ip -- the inode whose if_data area is changing
 * byte_diff -- the change in the number of bytes, positive or negative,
 *     requested for the if_data array.
 */
void
xfs_idata_realloc(
      xfs_inode_t *ip,
      int         byte_diff,
      int         whichfork)
{
      xfs_ifork_t *ifp;
      int         new_size;
      int         real_size;

      if (byte_diff == 0) {
            return;
      }

      ifp = XFS_IFORK_PTR(ip, whichfork);
      new_size = (int)ifp->if_bytes + byte_diff;
      ASSERT(new_size >= 0);

      if (new_size == 0) {
            if (ifp->if_u1.if_data != ifp->if_u2.if_inline_data) {
                  kmem_free(ifp->if_u1.if_data, ifp->if_real_bytes);
            }
            ifp->if_u1.if_data = NULL;
            real_size = 0;
      } else if (new_size <= sizeof(ifp->if_u2.if_inline_data)) {
            /*
             * If the valid extents/data can fit in if_inline_ext/data,
             * copy them from the malloc'd vector and free it.
             */
            if (ifp->if_u1.if_data == NULL) {
                  ifp->if_u1.if_data = ifp->if_u2.if_inline_data;
            } else if (ifp->if_u1.if_data != ifp->if_u2.if_inline_data) {
                  ASSERT(ifp->if_real_bytes != 0);
                  memcpy(ifp->if_u2.if_inline_data, ifp->if_u1.if_data,
                        new_size);
                  kmem_free(ifp->if_u1.if_data, ifp->if_real_bytes);
                  ifp->if_u1.if_data = ifp->if_u2.if_inline_data;
            }
            real_size = 0;
      } else {
            /*
             * Stuck with malloc/realloc.
             * For inline data, the underlying buffer must be
             * a multiple of 4 bytes in size so that it can be
             * logged and stay on word boundaries.  We enforce
             * that here.
             */
            real_size = roundup(new_size, 4);
            if (ifp->if_u1.if_data == NULL) {
                  ASSERT(ifp->if_real_bytes == 0);
                  ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP);
            } else if (ifp->if_u1.if_data != ifp->if_u2.if_inline_data) {
                  /*
                   * Only do the realloc if the underlying size
                   * is really changing.
                   */
                  if (ifp->if_real_bytes != real_size) {
                        ifp->if_u1.if_data =
                              kmem_realloc(ifp->if_u1.if_data,
                                          real_size,
                                          ifp->if_real_bytes,
                                          KM_SLEEP);
                  }
            } else {
                  ASSERT(ifp->if_real_bytes == 0);
                  ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP);
                  memcpy(ifp->if_u1.if_data, ifp->if_u2.if_inline_data,
                        ifp->if_bytes);
            }
      }
      ifp->if_real_bytes = real_size;
      ifp->if_bytes = new_size;
      ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
}




/*
 * Map inode to disk block and offset.
 *
 * mp -- the mount point structure for the current file system
 * tp -- the current transaction
 * ino -- the inode number of the inode to be located
 * imap -- this structure is filled in with the information necessary
 *     to retrieve the given inode from disk
 * flags -- flags to pass to xfs_dilocate indicating whether or not
 *     lookups in the inode btree were OK or not
 */
int
xfs_imap(
      xfs_mount_t *mp,
      xfs_trans_t *tp,
      xfs_ino_t   ino,
      xfs_imap_t  *imap,
      uint        flags)
{
      xfs_fsblock_t     fsbno;
      int         len;
      int         off;
      int         error;

      fsbno = imap->im_blkno ?
            XFS_DADDR_TO_FSB(mp, imap->im_blkno) : NULLFSBLOCK;
      error = xfs_dilocate(mp, tp, ino, &fsbno, &len, &off, flags);
      if (error != 0) {
            return error;
      }
      imap->im_blkno = XFS_FSB_TO_DADDR(mp, fsbno);
      imap->im_len = XFS_FSB_TO_BB(mp, len);
      imap->im_agblkno = XFS_FSB_TO_AGBNO(mp, fsbno);
      imap->im_ioffset = (ushort)off;
      imap->im_boffset = (ushort)(off << mp->m_sb.sb_inodelog);
      return 0;
}

void
xfs_idestroy_fork(
      xfs_inode_t *ip,
      int         whichfork)
{
      xfs_ifork_t *ifp;

      ifp = XFS_IFORK_PTR(ip, whichfork);
      if (ifp->if_broot != NULL) {
            kmem_free(ifp->if_broot, ifp->if_broot_bytes);
            ifp->if_broot = NULL;
      }

      /*
       * If the format is local, then we can't have an extents
       * array so just look for an inline data array.  If we're
       * not local then we may or may not have an extents list,
       * so check and free it up if we do.
       */
      if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
            if ((ifp->if_u1.if_data != ifp->if_u2.if_inline_data) &&
                (ifp->if_u1.if_data != NULL)) {
                  ASSERT(ifp->if_real_bytes != 0);
                  kmem_free(ifp->if_u1.if_data, ifp->if_real_bytes);
                  ifp->if_u1.if_data = NULL;
                  ifp->if_real_bytes = 0;
            }
      } else if ((ifp->if_flags & XFS_IFEXTENTS) &&
               ((ifp->if_flags & XFS_IFEXTIREC) ||
                ((ifp->if_u1.if_extents != NULL) &&
                 (ifp->if_u1.if_extents != ifp->if_u2.if_inline_ext)))) {
            ASSERT(ifp->if_real_bytes != 0);
            xfs_iext_destroy(ifp);
      }
      ASSERT(ifp->if_u1.if_extents == NULL ||
             ifp->if_u1.if_extents == ifp->if_u2.if_inline_ext);
      ASSERT(ifp->if_real_bytes == 0);
      if (whichfork == XFS_ATTR_FORK) {
            kmem_zone_free(xfs_ifork_zone, ip->i_afp);
            ip->i_afp = NULL;
      }
}

/*
 * This is called free all the memory associated with an inode.
 * It must free the inode itself and any buffers allocated for
 * if_extents/if_data and if_broot.  It must also free the lock
 * associated with the inode.
 */
void
xfs_idestroy(
      xfs_inode_t *ip)
{

      switch (ip->i_d.di_mode & S_IFMT) {
      case S_IFREG:
      case S_IFDIR:
      case S_IFLNK:
            xfs_idestroy_fork(ip, XFS_DATA_FORK);
            break;
      }
      if (ip->i_afp)
            xfs_idestroy_fork(ip, XFS_ATTR_FORK);
      mrfree(&ip->i_lock);
      mrfree(&ip->i_iolock);
      freesema(&ip->i_flock);

#ifdef XFS_VNODE_TRACE
      ktrace_free(ip->i_trace);
#endif
#ifdef XFS_BMAP_TRACE
      ktrace_free(ip->i_xtrace);
#endif
#ifdef XFS_BMBT_TRACE
      ktrace_free(ip->i_btrace);
#endif
#ifdef XFS_RW_TRACE
      ktrace_free(ip->i_rwtrace);
#endif
#ifdef XFS_ILOCK_TRACE
      ktrace_free(ip->i_lock_trace);
#endif
#ifdef XFS_DIR2_TRACE
      ktrace_free(ip->i_dir_trace);
#endif
      if (ip->i_itemp) {
            /*
             * Only if we are shutting down the fs will we see an
             * inode still in the AIL. If it is there, we should remove
             * it to prevent a use-after-free from occurring.
             */
            xfs_mount_t *mp = ip->i_mount;
            xfs_log_item_t    *lip = &ip->i_itemp->ili_item;
            int         s;

            ASSERT(((lip->li_flags & XFS_LI_IN_AIL) == 0) ||
                               XFS_FORCED_SHUTDOWN(ip->i_mount));
            if (lip->li_flags & XFS_LI_IN_AIL) {
                  AIL_LOCK(mp, s);
                  if (lip->li_flags & XFS_LI_IN_AIL)
                        xfs_trans_delete_ail(mp, lip, s);
                  else
                        AIL_UNLOCK(mp, s);
            }
            xfs_inode_item_destroy(ip);
      }
      kmem_zone_free(xfs_inode_zone, ip);
}


/*
 * Increment the pin count of the given buffer.
 * This value is protected by ipinlock spinlock in the mount structure.
 */
void
xfs_ipin(
      xfs_inode_t *ip)
{
      ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));

      atomic_inc(&ip->i_pincount);
}

/*
 * Decrement the pin count of the given inode, and wake up
 * anyone in xfs_iwait_unpin() if the count goes to 0.  The
 * inode must have been previously pinned with a call to xfs_ipin().
 */
void
xfs_iunpin(
      xfs_inode_t *ip)
{
      ASSERT(atomic_read(&ip->i_pincount) > 0);

      if (atomic_dec_and_lock(&ip->i_pincount, &ip->i_flags_lock)) {

            /*
             * If the inode is currently being reclaimed, the link between
             * the bhv_vnode and the xfs_inode will be broken after the
             * XFS_IRECLAIM* flag is set. Hence, if these flags are not
             * set, then we can move forward and mark the linux inode dirty
             * knowing that it is still valid as it won't freed until after
             * the bhv_vnode<->xfs_inode link is broken in xfs_reclaim. The
             * i_flags_lock is used to synchronise the setting of the
             * XFS_IRECLAIM* flags and the breaking of the link, and so we
             * can execute atomically w.r.t to reclaim by holding this lock
             * here.
             *
             * However, we still need to issue the unpin wakeup call as the
             * inode reclaim may be blocked waiting for the inode to become
             * unpinned.
             */

            if (!__xfs_iflags_test(ip, XFS_IRECLAIM|XFS_IRECLAIMABLE)) {
                  bhv_vnode_t *vp = XFS_ITOV_NULL(ip);
                  struct inode *inode = NULL;

                  BUG_ON(vp == NULL);
                  inode = vn_to_inode(vp);
                  BUG_ON(inode->i_state & I_CLEAR);

                  /* make sync come back and flush this inode */
                  if (!(inode->i_state & (I_NEW|I_FREEING)))
                        mark_inode_dirty_sync(inode);
            }
            spin_unlock(&ip->i_flags_lock);
            wake_up(&ip->i_ipin_wait);
      }
}

/*
 * This is called to wait for the given inode to be unpinned.
 * It will sleep until this happens.  The caller must have the
 * inode locked in at least shared mode so that the buffer cannot
 * be subsequently pinned once someone is waiting for it to be
 * unpinned.
 */
STATIC void
xfs_iunpin_wait(
      xfs_inode_t *ip)
{
      xfs_inode_log_item_t    *iip;
      xfs_lsn_t   lsn;

      ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE | MR_ACCESS));

      if (atomic_read(&ip->i_pincount) == 0) {
            return;
      }

      iip = ip->i_itemp;
      if (iip && iip->ili_last_lsn) {
            lsn = iip->ili_last_lsn;
      } else {
            lsn = (xfs_lsn_t)0;
      }

      /*
       * Give the log a push so we don't wait here too long.
       */
      xfs_log_force(ip->i_mount, lsn, XFS_LOG_FORCE);

      wait_event(ip->i_ipin_wait, (atomic_read(&ip->i_pincount) == 0));
}


/*
 * xfs_iextents_copy()
 *
 * This is called to copy the REAL extents (as opposed to the delayed
 * allocation extents) from the inode into the given buffer.  It
 * returns the number of bytes copied into the buffer.
 *
 * If there are no delayed allocation extents, then we can just
 * memcpy() the extents into the buffer.  Otherwise, we need to
 * examine each extent in turn and skip those which are delayed.
 */
int
xfs_iextents_copy(
      xfs_inode_t       *ip,
      xfs_bmbt_rec_t          *dp,
      int               whichfork)
{
      int               copied;
      int               i;
      xfs_ifork_t       *ifp;
      int               nrecs;
      xfs_fsblock_t           start_block;

      ifp = XFS_IFORK_PTR(ip, whichfork);
      ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE|MR_ACCESS));
      ASSERT(ifp->if_bytes > 0);

      nrecs = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
      XFS_BMAP_TRACE_EXLIST(ip, nrecs, whichfork);
      ASSERT(nrecs > 0);

      /*
       * There are some delayed allocation extents in the
       * inode, so copy the extents one at a time and skip
       * the delayed ones.  There must be at least one
       * non-delayed extent.
       */
      copied = 0;
      for (i = 0; i < nrecs; i++) {
            xfs_bmbt_rec_host_t *ep = xfs_iext_get_ext(ifp, i);
            start_block = xfs_bmbt_get_startblock(ep);
            if (ISNULLSTARTBLOCK(start_block)) {
                  /*
                   * It's a delayed allocation extent, so skip it.
                   */
                  continue;
            }

            /* Translate to on disk format */
            put_unaligned(cpu_to_be64(ep->l0), &dp->l0);
            put_unaligned(cpu_to_be64(ep->l1), &dp->l1);
            dp++;
            copied++;
      }
      ASSERT(copied != 0);
      xfs_validate_extents(ifp, copied, XFS_EXTFMT_INODE(ip));

      return (copied * (uint)sizeof(xfs_bmbt_rec_t));
}

/*
 * Each of the following cases stores data into the same region
 * of the on-disk inode, so only one of them can be valid at
 * any given time. While it is possible to have conflicting formats
 * and log flags, e.g. having XFS_ILOG_?DATA set when the fork is
 * in EXTENTS format, this can only happen when the fork has
 * changed formats after being modified but before being flushed.
 * In these cases, the format always takes precedence, because the
 * format indicates the current state of the fork.
 */
/*ARGSUSED*/
STATIC int
xfs_iflush_fork(
      xfs_inode_t       *ip,
      xfs_dinode_t            *dip,
      xfs_inode_log_item_t    *iip,
      int               whichfork,
      xfs_buf_t         *bp)
{
      char              *cp;
      xfs_ifork_t       *ifp;
      xfs_mount_t       *mp;
#ifdef XFS_TRANS_DEBUG
      int               first;
#endif
      static const short      brootflag[2] =
            { XFS_ILOG_DBROOT, XFS_ILOG_ABROOT };
      static const short      dataflag[2] =
            { XFS_ILOG_DDATA, XFS_ILOG_ADATA };
      static const short      extflag[2] =
            { XFS_ILOG_DEXT, XFS_ILOG_AEXT };

      if (iip == NULL)
            return 0;
      ifp = XFS_IFORK_PTR(ip, whichfork);
      /*
       * This can happen if we gave up in iformat in an error path,
       * for the attribute fork.
       */
      if (ifp == NULL) {
            ASSERT(whichfork == XFS_ATTR_FORK);
            return 0;
      }
      cp = XFS_DFORK_PTR(dip, whichfork);
      mp = ip->i_mount;
      switch (XFS_IFORK_FORMAT(ip, whichfork)) {
      case XFS_DINODE_FMT_LOCAL:
            if ((iip->ili_format.ilf_fields & dataflag[whichfork]) &&
                (ifp->if_bytes > 0)) {
                  ASSERT(ifp->if_u1.if_data != NULL);
                  ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
                  memcpy(cp, ifp->if_u1.if_data, ifp->if_bytes);
            }
            break;

      case XFS_DINODE_FMT_EXTENTS:
            ASSERT((ifp->if_flags & XFS_IFEXTENTS) ||
                   !(iip->ili_format.ilf_fields & extflag[whichfork]));
            ASSERT((xfs_iext_get_ext(ifp, 0) != NULL) ||
                  (ifp->if_bytes == 0));
            ASSERT((xfs_iext_get_ext(ifp, 0) == NULL) ||
                  (ifp->if_bytes > 0));
            if ((iip->ili_format.ilf_fields & extflag[whichfork]) &&
                (ifp->if_bytes > 0)) {
                  ASSERT(XFS_IFORK_NEXTENTS(ip, whichfork) > 0);
                  (void)xfs_iextents_copy(ip, (xfs_bmbt_rec_t *)cp,
                        whichfork);
            }
            break;

      case XFS_DINODE_FMT_BTREE:
            if ((iip->ili_format.ilf_fields & brootflag[whichfork]) &&
                (ifp->if_broot_bytes > 0)) {
                  ASSERT(ifp->if_broot != NULL);
                  ASSERT(ifp->if_broot_bytes <=
                         (XFS_IFORK_SIZE(ip, whichfork) +
                        XFS_BROOT_SIZE_ADJ));
                  xfs_bmbt_to_bmdr(ifp->if_broot, ifp->if_broot_bytes,
                        (xfs_bmdr_block_t *)cp,
                        XFS_DFORK_SIZE(dip, mp, whichfork));
            }
            break;

      case XFS_DINODE_FMT_DEV:
            if (iip->ili_format.ilf_fields & XFS_ILOG_DEV) {
                  ASSERT(whichfork == XFS_DATA_FORK);
                  dip->di_u.di_dev = cpu_to_be32(ip->i_df.if_u2.if_rdev);
            }
            break;

      case XFS_DINODE_FMT_UUID:
            if (iip->ili_format.ilf_fields & XFS_ILOG_UUID) {
                  ASSERT(whichfork == XFS_DATA_FORK);
                  memcpy(&dip->di_u.di_muuid, &ip->i_df.if_u2.if_uuid,
                        sizeof(uuid_t));
            }
            break;

      default:
            ASSERT(0);
            break;
      }

      return 0;
}

/*
 * xfs_iflush() will write a modified inode's changes out to the
 * inode's on disk home.  The caller must have the inode lock held
 * in at least shared mode and the inode flush semaphore must be
 * held as well.  The inode lock will still be held upon return from
 * the call and the caller is free to unlock it.
 * The inode flush lock will be unlocked when the inode reaches the disk.
 * The flags indicate how the inode's buffer should be written out.
 */
int
xfs_iflush(
      xfs_inode_t       *ip,
      uint              flags)
{
      xfs_inode_log_item_t    *iip;
      xfs_buf_t         *bp;
      xfs_dinode_t            *dip;
      xfs_mount_t       *mp;
      int               error;
      /* REFERENCED */
      xfs_inode_t       *iq;
      int               clcount;    /* count of inodes clustered */
      int               bufwasdelwri;
      struct hlist_node *entry;
      enum { INT_DELWRI = (1 << 0), INT_ASYNC = (1 << 1) };

      XFS_STATS_INC(xs_iflush_count);

      ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE|MR_ACCESS));
      ASSERT(issemalocked(&(ip->i_flock)));
      ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
             ip->i_d.di_nextents > ip->i_df.if_ext_max);

      iip = ip->i_itemp;
      mp = ip->i_mount;

      /*
       * If the inode isn't dirty, then just release the inode
       * flush lock and do nothing.
       */
      if ((ip->i_update_core == 0) &&
          ((iip == NULL) || !(iip->ili_format.ilf_fields & XFS_ILOG_ALL))) {
            ASSERT((iip != NULL) ?
                   !(iip->ili_item.li_flags & XFS_LI_IN_AIL) : 1);
            xfs_ifunlock(ip);
            return 0;
      }

      /*
       * We can't flush the inode until it is unpinned, so
       * wait for it.  We know noone new can pin it, because
       * we are holding the inode lock shared and you need
       * to hold it exclusively to pin the inode.
       */
      xfs_iunpin_wait(ip);

      /*
       * This may have been unpinned because the filesystem is shutting
       * down forcibly. If that's the case we must not write this inode
       * to disk, because the log record didn't make it to disk!
       */
      if (XFS_FORCED_SHUTDOWN(mp)) {
            ip->i_update_core = 0;
            if (iip)
                  iip->ili_format.ilf_fields = 0;
            xfs_ifunlock(ip);
            return XFS_ERROR(EIO);
      }

      /*
       * Get the buffer containing the on-disk inode.
       */
      error = xfs_itobp(mp, NULL, ip, &dip, &bp, 0, 0);
      if (error) {
            xfs_ifunlock(ip);
            return error;
      }

      /*
       * Decide how buffer will be flushed out.  This is done before
       * the call to xfs_iflush_int because this field is zeroed by it.
       */
      if (iip != NULL && iip->ili_format.ilf_fields != 0) {
            /*
             * Flush out the inode buffer according to the directions
             * of the caller.  In the cases where the caller has given
             * us a choice choose the non-delwri case.  This is because
             * the inode is in the AIL and we need to get it out soon.
             */
            switch (flags) {
            case XFS_IFLUSH_SYNC:
            case XFS_IFLUSH_DELWRI_ELSE_SYNC:
                  flags = 0;
                  break;
            case XFS_IFLUSH_ASYNC:
            case XFS_IFLUSH_DELWRI_ELSE_ASYNC:
                  flags = INT_ASYNC;
                  break;
            case XFS_IFLUSH_DELWRI:
                  flags = INT_DELWRI;
                  break;
            default:
                  ASSERT(0);
                  flags = 0;
                  break;
            }
      } else {
            switch (flags) {
            case XFS_IFLUSH_DELWRI_ELSE_SYNC:
            case XFS_IFLUSH_DELWRI_ELSE_ASYNC:
            case XFS_IFLUSH_DELWRI:
                  flags = INT_DELWRI;
                  break;
            case XFS_IFLUSH_ASYNC:
                  flags = INT_ASYNC;
                  break;
            case XFS_IFLUSH_SYNC:
                  flags = 0;
                  break;
            default:
                  ASSERT(0);
                  flags = 0;
                  break;
            }
      }

      /*
       * First flush out the inode that xfs_iflush was called with.
       */
      error = xfs_iflush_int(ip, bp);
      if (error) {
            goto corrupt_out;
      }

      /*
       * inode clustering:
       * see if other inodes can be gathered into this write
       */
      spin_lock(&ip->i_cluster->icl_lock);
      ip->i_cluster->icl_buf = bp;

      clcount = 0;
      hlist_for_each_entry(iq, entry, &ip->i_cluster->icl_inodes, i_cnode) {
            if (iq == ip)
                  continue;

            /*
             * Do an un-protected check to see if the inode is dirty and
             * is a candidate for flushing.  These checks will be repeated
             * later after the appropriate locks are acquired.
             */
            iip = iq->i_itemp;
            if ((iq->i_update_core == 0) &&
                ((iip == NULL) ||
                 !(iip->ili_format.ilf_fields & XFS_ILOG_ALL)) &&
                  xfs_ipincount(iq) == 0) {
                  continue;
            }

            /*
             * Try to get locks.  If any are unavailable,
             * then this inode cannot be flushed and is skipped.
             */

            /* get inode locks (just i_lock) */
            if (xfs_ilock_nowait(iq, XFS_ILOCK_SHARED)) {
                  /* get inode flush lock */
                  if (xfs_iflock_nowait(iq)) {
                        /* check if pinned */
                        if (xfs_ipincount(iq) == 0) {
                              /* arriving here means that
                               * this inode can be flushed.
                               * first re-check that it's
                               * dirty
                               */
                              iip = iq->i_itemp;
                              if ((iq->i_update_core != 0)||
                                  ((iip != NULL) &&
                                   (iip->ili_format.ilf_fields & XFS_ILOG_ALL))) {
                                    clcount++;
                                    error = xfs_iflush_int(iq, bp);
                                    if (error) {
                                          xfs_iunlock(iq,
                                                    XFS_ILOCK_SHARED);
                                          goto cluster_corrupt_out;
                                    }
                              } else {
                                    xfs_ifunlock(iq);
                              }
                        } else {
                              xfs_ifunlock(iq);
                        }
                  }
                  xfs_iunlock(iq, XFS_ILOCK_SHARED);
            }
      }
      spin_unlock(&ip->i_cluster->icl_lock);

      if (clcount) {
            XFS_STATS_INC(xs_icluster_flushcnt);
            XFS_STATS_ADD(xs_icluster_flushinode, clcount);
      }

      /*
       * If the buffer is pinned then push on the log so we won't
       * get stuck waiting in the write for too long.
       */
      if (XFS_BUF_ISPINNED(bp)){
            xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE);
      }

      if (flags & INT_DELWRI) {
            xfs_bdwrite(mp, bp);
      } else if (flags & INT_ASYNC) {
            xfs_bawrite(mp, bp);
      } else {
            error = xfs_bwrite(mp, bp);
      }
      return error;

corrupt_out:
      xfs_buf_relse(bp);
      xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
      xfs_iflush_abort(ip);
      /*
       * Unlocks the flush lock
       */
      return XFS_ERROR(EFSCORRUPTED);

cluster_corrupt_out:
      /* Corruption detected in the clustering loop.  Invalidate the
       * inode buffer and shut down the filesystem.
       */
      spin_unlock(&ip->i_cluster->icl_lock);

      /*
       * Clean up the buffer.  If it was B_DELWRI, just release it --
       * brelse can handle it with no problems.  If not, shut down the
       * filesystem before releasing the buffer.
       */
      if ((bufwasdelwri= XFS_BUF_ISDELAYWRITE(bp))) {
            xfs_buf_relse(bp);
      }

      xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);

      if(!bufwasdelwri)  {
            /*
             * Just like incore_relse: if we have b_iodone functions,
             * mark the buffer as an error and call them.  Otherwise
             * mark it as stale and brelse.
             */
            if (XFS_BUF_IODONE_FUNC(bp)) {
                  XFS_BUF_CLR_BDSTRAT_FUNC(bp);
                  XFS_BUF_UNDONE(bp);
                  XFS_BUF_STALE(bp);
                  XFS_BUF_SHUT(bp);
                  XFS_BUF_ERROR(bp,EIO);
                  xfs_biodone(bp);
            } else {
                  XFS_BUF_STALE(bp);
                  xfs_buf_relse(bp);
            }
      }

      xfs_iflush_abort(iq);
      /*
       * Unlocks the flush lock
       */
      return XFS_ERROR(EFSCORRUPTED);
}


STATIC int
xfs_iflush_int(
      xfs_inode_t       *ip,
      xfs_buf_t         *bp)
{
      xfs_inode_log_item_t    *iip;
      xfs_dinode_t            *dip;
      xfs_mount_t       *mp;
#ifdef XFS_TRANS_DEBUG
      int               first;
#endif
      SPLDECL(s);

      ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE|MR_ACCESS));
      ASSERT(issemalocked(&(ip->i_flock)));
      ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
             ip->i_d.di_nextents > ip->i_df.if_ext_max);

      iip = ip->i_itemp;
      mp = ip->i_mount;


      /*
       * If the inode isn't dirty, then just release the inode
       * flush lock and do nothing.
       */
      if ((ip->i_update_core == 0) &&
          ((iip == NULL) || !(iip->ili_format.ilf_fields & XFS_ILOG_ALL))) {
            xfs_ifunlock(ip);
            return 0;
      }

      /* set *dip = inode's place in the buffer */
      dip = (xfs_dinode_t *)xfs_buf_offset(bp, ip->i_boffset);

      /*
       * Clear i_update_core before copying out the data.
       * This is for coordination with our timestamp updates
       * that don't hold the inode lock. They will always
       * update the timestamps BEFORE setting i_update_core,
       * so if we clear i_update_core after they set it we
       * are guaranteed to see their updates to the timestamps.
       * I believe that this depends on strongly ordered memory
       * semantics, but we have that.  We use the SYNCHRONIZE
       * macro to make sure that the compiler does not reorder
       * the i_update_core access below the data copy below.
       */
      ip->i_update_core = 0;
      SYNCHRONIZE();

      /*
       * Make sure to get the latest atime from the Linux inode.
       */
      xfs_synchronize_atime(ip);

      if (XFS_TEST_ERROR(be16_to_cpu(dip->di_core.di_magic) != XFS_DINODE_MAGIC,
                         mp, XFS_ERRTAG_IFLUSH_1, XFS_RANDOM_IFLUSH_1)) {
            xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                "xfs_iflush: Bad inode %Lu magic number 0x%x, ptr 0x%p",
                  ip->i_ino, be16_to_cpu(dip->di_core.di_magic), dip);
            goto corrupt_out;
      }
      if (XFS_TEST_ERROR(ip->i_d.di_magic != XFS_DINODE_MAGIC,
                        mp, XFS_ERRTAG_IFLUSH_2, XFS_RANDOM_IFLUSH_2)) {
            xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                  "xfs_iflush: Bad inode %Lu, ptr 0x%p, magic number 0x%x",
                  ip->i_ino, ip, ip->i_d.di_magic);
            goto corrupt_out;
      }
      if ((ip->i_d.di_mode & S_IFMT) == S_IFREG) {
            if (XFS_TEST_ERROR(
                (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
                (ip->i_d.di_format != XFS_DINODE_FMT_BTREE),
                mp, XFS_ERRTAG_IFLUSH_3, XFS_RANDOM_IFLUSH_3)) {
                  xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                        "xfs_iflush: Bad regular inode %Lu, ptr 0x%p",
                        ip->i_ino, ip);
                  goto corrupt_out;
            }
      } else if ((ip->i_d.di_mode & S_IFMT) == S_IFDIR) {
            if (XFS_TEST_ERROR(
                (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS) &&
                (ip->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
                (ip->i_d.di_format != XFS_DINODE_FMT_LOCAL),
                mp, XFS_ERRTAG_IFLUSH_4, XFS_RANDOM_IFLUSH_4)) {
                  xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                        "xfs_iflush: Bad directory inode %Lu, ptr 0x%p",
                        ip->i_ino, ip);
                  goto corrupt_out;
            }
      }
      if (XFS_TEST_ERROR(ip->i_d.di_nextents + ip->i_d.di_anextents >
                        ip->i_d.di_nblocks, mp, XFS_ERRTAG_IFLUSH_5,
                        XFS_RANDOM_IFLUSH_5)) {
            xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                  "xfs_iflush: detected corrupt incore inode %Lu, total extents = %d, nblocks = %Ld, ptr 0x%p",
                  ip->i_ino,
                  ip->i_d.di_nextents + ip->i_d.di_anextents,
                  ip->i_d.di_nblocks,
                  ip);
            goto corrupt_out;
      }
      if (XFS_TEST_ERROR(ip->i_d.di_forkoff > mp->m_sb.sb_inodesize,
                        mp, XFS_ERRTAG_IFLUSH_6, XFS_RANDOM_IFLUSH_6)) {
            xfs_cmn_err(XFS_PTAG_IFLUSH, CE_ALERT, mp,
                  "xfs_iflush: bad inode %Lu, forkoff 0x%x, ptr 0x%p",
                  ip->i_ino, ip->i_d.di_forkoff, ip);
            goto corrupt_out;
      }
      /*
       * bump the flush iteration count, used to detect flushes which
       * postdate a log record during recovery.
       */

      ip->i_d.di_flushiter++;

      /*
       * Copy the dirty parts of the inode into the on-disk
       * inode.  We always copy out the core of the inode,
       * because if the inode is dirty at all the core must
       * be.
       */
      xfs_dinode_to_disk(&dip->di_core, &ip->i_d);

      /* Wrap, we never let the log put out DI_MAX_FLUSH */
      if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
            ip->i_d.di_flushiter = 0;

      /*
       * If this is really an old format inode and the superblock version
       * has not been updated to support only new format inodes, then
       * convert back to the old inode format.  If the superblock version
       * has been updated, then make the conversion permanent.
       */
      ASSERT(ip->i_d.di_version == XFS_DINODE_VERSION_1 ||
             XFS_SB_VERSION_HASNLINK(&mp->m_sb));
      if (ip->i_d.di_version == XFS_DINODE_VERSION_1) {
            if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) {
                  /*
                   * Convert it back.
                   */
                  ASSERT(ip->i_d.di_nlink <= XFS_MAXLINK_1);
                  dip->di_core.di_onlink = cpu_to_be16(ip->i_d.di_nlink);
            } else {
                  /*
                   * The superblock version has already been bumped,
                   * so just make the conversion to the new inode
                   * format permanent.
                   */
                  ip->i_d.di_version = XFS_DINODE_VERSION_2;
                  dip->di_core.di_version =  XFS_DINODE_VERSION_2;
                  ip->i_d.di_onlink = 0;
                  dip->di_core.di_onlink = 0;
                  memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
                  memset(&(dip->di_core.di_pad[0]), 0,
                        sizeof(dip->di_core.di_pad));
                  ASSERT(ip->i_d.di_projid == 0);
            }
      }

      if (xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK, bp) == EFSCORRUPTED) {
            goto corrupt_out;
      }

      if (XFS_IFORK_Q(ip)) {
            /*
             * The only error from xfs_iflush_fork is on the data fork.
             */
            (void) xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK, bp);
      }
      xfs_inobp_check(mp, bp);

      /*
       * We've recorded everything logged in the inode, so we'd
       * like to clear the ilf_fields bits so we don't log and
       * flush things unnecessarily.  However, we can't stop
       * logging all this information until the data we've copied
       * into the disk buffer is written to disk.  If we did we might
       * overwrite the copy of the inode in the log with all the
       * data after re-logging only part of it, and in the face of
       * a crash we wouldn't have all the data we need to recover.
       *
       * What we do is move the bits to the ili_last_fields field.
       * When logging the inode, these bits are moved back to the
       * ilf_fields field.  In the xfs_iflush_done() routine we
       * clear ili_last_fields, since we know that the information
       * those bits represent is permanently on disk.  As long as
       * the flush completes before the inode is logged again, then
       * both ilf_fields and ili_last_fields will be cleared.
       *
       * We can play with the ilf_fields bits here, because the inode
       * lock must be held exclusively in order to set bits there
       * and the flush lock protects the ili_last_fields bits.
       * Set ili_logged so the flush done
       * routine can tell whether or not to look in the AIL.
       * Also, store the current LSN of the inode so that we can tell
       * whether the item has moved in the AIL from xfs_iflush_done().
       * In order to read the lsn we need the AIL lock, because
       * it is a 64 bit value that cannot be read atomically.
       */
      if (iip != NULL && iip->ili_format.ilf_fields != 0) {
            iip->ili_last_fields = iip->ili_format.ilf_fields;
            iip->ili_format.ilf_fields = 0;
            iip->ili_logged = 1;

            ASSERT(sizeof(xfs_lsn_t) == 8);     /* don't lock if it shrinks */
            AIL_LOCK(mp,s);
            iip->ili_flush_lsn = iip->ili_item.li_lsn;
            AIL_UNLOCK(mp, s);

            /*
             * Attach the function xfs_iflush_done to the inode's
             * buffer.  This will remove the inode from the AIL
             * and unlock the inode's flush lock when the inode is
             * completely written to disk.
             */
            xfs_buf_attach_iodone(bp, (void(*)(xfs_buf_t*,xfs_log_item_t*))
                              xfs_iflush_done, (xfs_log_item_t *)iip);

            ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
            ASSERT(XFS_BUF_IODONE_FUNC(bp) != NULL);
      } else {
            /*
             * We're flushing an inode which is not in the AIL and has
             * not been logged but has i_update_core set.  For this
             * case we can use a B_DELWRI flush and immediately drop
             * the inode flush lock because we can avoid the whole
             * AIL state thing.  It's OK to drop the flush lock now,
             * because we've already locked the buffer and to do anything
             * you really need both.
             */
            if (iip != NULL) {
                  ASSERT(iip->ili_logged == 0);
                  ASSERT(iip->ili_last_fields == 0);
                  ASSERT((iip->ili_item.li_flags & XFS_LI_IN_AIL) == 0);
            }
            xfs_ifunlock(ip);
      }

      return 0;

corrupt_out:
      return XFS_ERROR(EFSCORRUPTED);
}


/*
 * Flush all inactive inodes in mp.
 */
void
xfs_iflush_all(
      xfs_mount_t *mp)
{
      xfs_inode_t *ip;
      bhv_vnode_t *vp;

 again:
      XFS_MOUNT_ILOCK(mp);
      ip = mp->m_inodes;
      if (ip == NULL)
            goto out;

      do {
            /* Make sure we skip markers inserted by sync */
            if (ip->i_mount == NULL) {
                  ip = ip->i_mnext;
                  continue;
            }

            vp = XFS_ITOV_NULL(ip);
            if (!vp) {
                  XFS_MOUNT_IUNLOCK(mp);
                  xfs_finish_reclaim(ip, 0, XFS_IFLUSH_ASYNC);
                  goto again;
            }

            ASSERT(vn_count(vp) == 0);

            ip = ip->i_mnext;
      } while (ip != mp->m_inodes);
 out:
      XFS_MOUNT_IUNLOCK(mp);
}

/*
 * xfs_iaccess: check accessibility of inode for mode.
 */
int
xfs_iaccess(
      xfs_inode_t *ip,
      mode_t            mode,
      cred_t            *cr)
{
      int         error;
      mode_t            orgmode = mode;
      struct inode      *inode = vn_to_inode(XFS_ITOV(ip));

      if (mode & S_IWUSR) {
            umode_t           imode = inode->i_mode;

            if (IS_RDONLY(inode) &&
                (S_ISREG(imode) || S_ISDIR(imode) || S_ISLNK(imode)))
                  return XFS_ERROR(EROFS);

            if (IS_IMMUTABLE(inode))
                  return XFS_ERROR(EACCES);
      }

      /*
       * If there's an Access Control List it's used instead of
       * the mode bits.
       */
      if ((error = _ACL_XFS_IACCESS(ip, mode, cr)) != -1)
            return error ? XFS_ERROR(error) : 0;

      if (current_fsuid(cr) != ip->i_d.di_uid) {
            mode >>= 3;
            if (!in_group_p((gid_t)ip->i_d.di_gid))
                  mode >>= 3;
      }

      /*
       * If the DACs are ok we don't need any capability check.
       */
      if ((ip->i_d.di_mode & mode) == mode)
            return 0;
      /*
       * Read/write DACs are always overridable.
       * Executable DACs are overridable if at least one exec bit is set.
       */
      if (!(orgmode & S_IXUSR) ||
          (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode))
            if (capable_cred(cr, CAP_DAC_OVERRIDE))
                  return 0;

      if ((orgmode == S_IRUSR) ||
          (S_ISDIR(inode->i_mode) && (!(orgmode & S_IWUSR)))) {
            if (capable_cred(cr, CAP_DAC_READ_SEARCH))
                  return 0;
#ifdef      NOISE
            cmn_err(CE_NOTE, "Ick: mode=%o, orgmode=%o", mode, orgmode);
#endif      /* NOISE */
            return XFS_ERROR(EACCES);
      }
      return XFS_ERROR(EACCES);
}

/*
 * xfs_iroundup: round up argument to next power of two
 */
uint
xfs_iroundup(
      uint  v)
{
      int i;
      uint m;

      if ((v & (v - 1)) == 0)
            return v;
      ASSERT((v & 0x80000000) == 0);
      if ((v & (v + 1)) == 0)
            return v + 1;
      for (i = 0, m = 1; i < 31; i++, m <<= 1) {
            if (v & m)
                  continue;
            v |= m;
            if ((v & (v + 1)) == 0)
                  return v + 1;
      }
      ASSERT(0);
      return( 0 );
}

#ifdef XFS_ILOCK_TRACE
ktrace_t    *xfs_ilock_trace_buf;

void
xfs_ilock_trace(xfs_inode_t *ip, int lock, unsigned int lockflags, inst_t *ra)
{
      ktrace_enter(ip->i_lock_trace,
                 (void *)ip,
                 (void *)(unsigned long)lock, /* 1 = LOCK, 3=UNLOCK, etc */
                 (void *)(unsigned long)lockflags, /* XFS_ILOCK_EXCL etc */
                 (void *)ra,        /* caller of ilock */
                 (void *)(unsigned long)current_cpu(),
                 (void *)(unsigned long)current_pid(),
                 NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL);
}
#endif

/*
 * Return a pointer to the extent record at file index idx.
 */
xfs_bmbt_rec_host_t *
xfs_iext_get_ext(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_extnum_t      idx)        /* index of target extent */
{
      ASSERT(idx >= 0);
      if ((ifp->if_flags & XFS_IFEXTIREC) && (idx == 0)) {
            return ifp->if_u1.if_ext_irec->er_extbuf;
      } else if (ifp->if_flags & XFS_IFEXTIREC) {
            xfs_ext_irec_t    *erp;       /* irec pointer */
            int         erp_idx = 0;      /* irec index */
            xfs_extnum_t      page_idx = idx;   /* ext index in target list */

            erp = xfs_iext_idx_to_irec(ifp, &page_idx, &erp_idx, 0);
            return &erp->er_extbuf[page_idx];
      } else if (ifp->if_bytes) {
            return &ifp->if_u1.if_extents[idx];
      } else {
            return NULL;
      }
}

/*
 * Insert new item(s) into the extent records for incore inode
 * fork 'ifp'.  'count' new items are inserted at index 'idx'.
 */
void
xfs_iext_insert(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_extnum_t      idx,        /* starting index of new items */
      xfs_extnum_t      count,            /* number of inserted items */
      xfs_bmbt_irec_t   *new)       /* items to insert */
{
      xfs_extnum_t      i;          /* extent record index */

      ASSERT(ifp->if_flags & XFS_IFEXTENTS);
      xfs_iext_add(ifp, idx, count);
      for (i = idx; i < idx + count; i++, new++)
            xfs_bmbt_set_all(xfs_iext_get_ext(ifp, i), new);
}

/*
 * This is called when the amount of space required for incore file
 * extents needs to be increased. The ext_diff parameter stores the
 * number of new extents being added and the idx parameter contains
 * the extent index where the new extents will be added. If the new
 * extents are being appended, then we just need to (re)allocate and
 * initialize the space. Otherwise, if the new extents are being
 * inserted into the middle of the existing entries, a bit more work
 * is required to make room for the new extents to be inserted. The
 * caller is responsible for filling in the new extent entries upon
 * return.
 */
void
xfs_iext_add(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_extnum_t      idx,        /* index to begin adding exts */
      int         ext_diff)   /* number of extents to add */
{
      int         byte_diff;  /* new bytes being added */
      int         new_size;   /* size of extents after adding */
      xfs_extnum_t      nextents;   /* number of extents in file */

      nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
      ASSERT((idx >= 0) && (idx <= nextents));
      byte_diff = ext_diff * sizeof(xfs_bmbt_rec_t);
      new_size = ifp->if_bytes + byte_diff;
      /*
       * If the new number of extents (nextents + ext_diff)
       * fits inside the inode, then continue to use the inline
       * extent buffer.
       */
      if (nextents + ext_diff <= XFS_INLINE_EXTS) {
            if (idx < nextents) {
                  memmove(&ifp->if_u2.if_inline_ext[idx + ext_diff],
                        &ifp->if_u2.if_inline_ext[idx],
                        (nextents - idx) * sizeof(xfs_bmbt_rec_t));
                  memset(&ifp->if_u2.if_inline_ext[idx], 0, byte_diff);
            }
            ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
            ifp->if_real_bytes = 0;
            ifp->if_lastex = nextents + ext_diff;
      }
      /*
       * Otherwise use a linear (direct) extent list.
       * If the extents are currently inside the inode,
       * xfs_iext_realloc_direct will switch us from
       * inline to direct extent allocation mode.
       */
      else if (nextents + ext_diff <= XFS_LINEAR_EXTS) {
            xfs_iext_realloc_direct(ifp, new_size);
            if (idx < nextents) {
                  memmove(&ifp->if_u1.if_extents[idx + ext_diff],
                        &ifp->if_u1.if_extents[idx],
                        (nextents - idx) * sizeof(xfs_bmbt_rec_t));
                  memset(&ifp->if_u1.if_extents[idx], 0, byte_diff);
            }
      }
      /* Indirection array */
      else {
            xfs_ext_irec_t    *erp;
            int         erp_idx = 0;
            int         page_idx = idx;

            ASSERT(nextents + ext_diff > XFS_LINEAR_EXTS);
            if (ifp->if_flags & XFS_IFEXTIREC) {
                  erp = xfs_iext_idx_to_irec(ifp, &page_idx, &erp_idx, 1);
            } else {
                  xfs_iext_irec_init(ifp);
                  ASSERT(ifp->if_flags & XFS_IFEXTIREC);
                  erp = ifp->if_u1.if_ext_irec;
            }
            /* Extents fit in target extent page */
            if (erp && erp->er_extcount + ext_diff <= XFS_LINEAR_EXTS) {
                  if (page_idx < erp->er_extcount) {
                        memmove(&erp->er_extbuf[page_idx + ext_diff],
                              &erp->er_extbuf[page_idx],
                              (erp->er_extcount - page_idx) *
                              sizeof(xfs_bmbt_rec_t));
                        memset(&erp->er_extbuf[page_idx], 0, byte_diff);
                  }
                  erp->er_extcount += ext_diff;
                  xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, ext_diff);
            }
            /* Insert a new extent page */
            else if (erp) {
                  xfs_iext_add_indirect_multi(ifp,
                        erp_idx, page_idx, ext_diff);
            }
            /*
             * If extent(s) are being appended to the last page in
             * the indirection array and the new extent(s) don't fit
             * in the page, then erp is NULL and erp_idx is set to
             * the next index needed in the indirection array.
             */
            else {
                  int   count = ext_diff;

                  while (count) {
                        erp = xfs_iext_irec_new(ifp, erp_idx);
                        erp->er_extcount = count;
                        count -= MIN(count, (int)XFS_LINEAR_EXTS);
                        if (count) {
                              erp_idx++;
                        }
                  }
            }
      }
      ifp->if_bytes = new_size;
}

/*
 * This is called when incore extents are being added to the indirection
 * array and the new extents do not fit in the target extent list. The
 * erp_idx parameter contains the irec index for the target extent list
 * in the indirection array, and the idx parameter contains the extent
 * index within the list. The number of extents being added is stored
 * in the count parameter.
 *
 *    |-------|   |-------|
 *    |       |   |       |    idx - number of extents before idx
 *    |  idx  |   | count |
 *    |       |   |       |    count - number of extents being inserted at idx
 *    |-------|   |-------|
 *    | count |   | nex2  |    nex2 - number of extents after idx + count
 *    |-------|   |-------|
 */
void
xfs_iext_add_indirect_multi(
      xfs_ifork_t *ifp,             /* inode fork pointer */
      int         erp_idx,          /* target extent irec index */
      xfs_extnum_t      idx,              /* index within target list */
      int         count)                  /* new extents being added */
{
      int         byte_diff;        /* new bytes being added */
      xfs_ext_irec_t    *erp;             /* pointer to irec entry */
      xfs_extnum_t      ext_diff;         /* number of extents to add */
      xfs_extnum_t      ext_cnt;          /* new extents still needed */
      xfs_extnum_t      nex2;             /* extents after idx + count */
      xfs_bmbt_rec_t    *nex2_ep = NULL;  /* temp list for nex2 extents */
      int         nlists;                 /* number of irec's (lists) */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      erp = &ifp->if_u1.if_ext_irec[erp_idx];
      nex2 = erp->er_extcount - idx;
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;

      /*
       * Save second part of target extent list
       * (all extents past */
      if (nex2) {
            byte_diff = nex2 * sizeof(xfs_bmbt_rec_t);
            nex2_ep = (xfs_bmbt_rec_t *) kmem_alloc(byte_diff, KM_SLEEP);
            memmove(nex2_ep, &erp->er_extbuf[idx], byte_diff);
            erp->er_extcount -= nex2;
            xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, -nex2);
            memset(&erp->er_extbuf[idx], 0, byte_diff);
      }

      /*
       * Add the new extents to the end of the target
       * list, then allocate new irec record(s) and
       * extent buffer(s) as needed to store the rest
       * of the new extents.
       */
      ext_cnt = count;
      ext_diff = MIN(ext_cnt, (int)XFS_LINEAR_EXTS - erp->er_extcount);
      if (ext_diff) {
            erp->er_extcount += ext_diff;
            xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, ext_diff);
            ext_cnt -= ext_diff;
      }
      while (ext_cnt) {
            erp_idx++;
            erp = xfs_iext_irec_new(ifp, erp_idx);
            ext_diff = MIN(ext_cnt, (int)XFS_LINEAR_EXTS);
            erp->er_extcount = ext_diff;
            xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, ext_diff);
            ext_cnt -= ext_diff;
      }

      /* Add nex2 extents back to indirection array */
      if (nex2) {
            xfs_extnum_t      ext_avail;
            int         i;

            byte_diff = nex2 * sizeof(xfs_bmbt_rec_t);
            ext_avail = XFS_LINEAR_EXTS - erp->er_extcount;
            i = 0;
            /*
             * If nex2 extents fit in the current page, append
             * nex2_ep after the new extents.
             */
            if (nex2 <= ext_avail) {
                  i = erp->er_extcount;
            }
            /*
             * Otherwise, check if space is available in the
             * next page.
             */
            else if ((erp_idx < nlists - 1) &&
                   (nex2 <= (ext_avail = XFS_LINEAR_EXTS -
                    ifp->if_u1.if_ext_irec[erp_idx+1].er_extcount))) {
                  erp_idx++;
                  erp++;
                  /* Create a hole for nex2 extents */
                  memmove(&erp->er_extbuf[nex2], erp->er_extbuf,
                        erp->er_extcount * sizeof(xfs_bmbt_rec_t));
            }
            /*
             * Final choice, create a new extent page for
             * nex2 extents.
             */
            else {
                  erp_idx++;
                  erp = xfs_iext_irec_new(ifp, erp_idx);
            }
            memmove(&erp->er_extbuf[i], nex2_ep, byte_diff);
            kmem_free(nex2_ep, byte_diff);
            erp->er_extcount += nex2;
            xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, nex2);
      }
}

/*
 * This is called when the amount of space required for incore file
 * extents needs to be decreased. The ext_diff parameter stores the
 * number of extents to be removed and the idx parameter contains
 * the extent index where the extents will be removed from.
 *
 * If the amount of space needed has decreased below the linear
 * limit, XFS_IEXT_BUFSZ, then switch to using the contiguous
 * extent array.  Otherwise, use kmem_realloc() to adjust the
 * size to what is needed.
 */
void
xfs_iext_remove(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_extnum_t      idx,        /* index to begin removing exts */
      int         ext_diff)   /* number of extents to remove */
{
      xfs_extnum_t      nextents;   /* number of extents in file */
      int         new_size;   /* size of extents after removal */

      ASSERT(ext_diff > 0);
      nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
      new_size = (nextents - ext_diff) * sizeof(xfs_bmbt_rec_t);

      if (new_size == 0) {
            xfs_iext_destroy(ifp);
      } else if (ifp->if_flags & XFS_IFEXTIREC) {
            xfs_iext_remove_indirect(ifp, idx, ext_diff);
      } else if (ifp->if_real_bytes) {
            xfs_iext_remove_direct(ifp, idx, ext_diff);
      } else {
            xfs_iext_remove_inline(ifp, idx, ext_diff);
      }
      ifp->if_bytes = new_size;
}

/*
 * This removes ext_diff extents from the inline buffer, beginning
 * at extent index idx.
 */
void
xfs_iext_remove_inline(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_extnum_t      idx,        /* index to begin removing exts */
      int         ext_diff)   /* number of extents to remove */
{
      int         nextents;   /* number of extents in file */

      ASSERT(!(ifp->if_flags & XFS_IFEXTIREC));
      ASSERT(idx < XFS_INLINE_EXTS);
      nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
      ASSERT(((nextents - ext_diff) > 0) &&
            (nextents - ext_diff) < XFS_INLINE_EXTS);

      if (idx + ext_diff < nextents) {
            memmove(&ifp->if_u2.if_inline_ext[idx],
                  &ifp->if_u2.if_inline_ext[idx + ext_diff],
                  (nextents - (idx + ext_diff)) *
                   sizeof(xfs_bmbt_rec_t));
            memset(&ifp->if_u2.if_inline_ext[nextents - ext_diff],
                  0, ext_diff * sizeof(xfs_bmbt_rec_t));
      } else {
            memset(&ifp->if_u2.if_inline_ext[idx], 0,
                  ext_diff * sizeof(xfs_bmbt_rec_t));
      }
}

/*
 * This removes ext_diff extents from a linear (direct) extent list,
 * beginning at extent index idx. If the extents are being removed
 * from the end of the list (ie. truncate) then we just need to re-
 * allocate the list to remove the extra space. Otherwise, if the
 * extents are being removed from the middle of the existing extent
 * entries, then we first need to move the extent records beginning
 * at idx + ext_diff up in the list to overwrite the records being
 * removed, then remove the extra space via kmem_realloc.
 */
void
xfs_iext_remove_direct(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_extnum_t      idx,        /* index to begin removing exts */
      int         ext_diff)   /* number of extents to remove */
{
      xfs_extnum_t      nextents;   /* number of extents in file */
      int         new_size;   /* size of extents after removal */

      ASSERT(!(ifp->if_flags & XFS_IFEXTIREC));
      new_size = ifp->if_bytes -
            (ext_diff * sizeof(xfs_bmbt_rec_t));
      nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);

      if (new_size == 0) {
            xfs_iext_destroy(ifp);
            return;
      }
      /* Move extents up in the list (if needed) */
      if (idx + ext_diff < nextents) {
            memmove(&ifp->if_u1.if_extents[idx],
                  &ifp->if_u1.if_extents[idx + ext_diff],
                  (nextents - (idx + ext_diff)) *
                   sizeof(xfs_bmbt_rec_t));
      }
      memset(&ifp->if_u1.if_extents[nextents - ext_diff],
            0, ext_diff * sizeof(xfs_bmbt_rec_t));
      /*
       * Reallocate the direct extent list. If the extents
       * will fit inside the inode then xfs_iext_realloc_direct
       * will switch from direct to inline extent allocation
       * mode for us.
       */
      xfs_iext_realloc_direct(ifp, new_size);
      ifp->if_bytes = new_size;
}

/*
 * This is called when incore extents are being removed from the
 * indirection array and the extents being removed span multiple extent
 * buffers. The idx parameter contains the file extent index where we
 * want to begin removing extents, and the count parameter contains
 * how many extents need to be removed.
 *
 *    |-------|   |-------|
 *    | nex1  |   |       |    nex1 - number of extents before idx
 *    |-------|   | count |
 *    |       |   |       |    count - number of extents being removed at idx
 *    | count |   |-------|
 *    |       |   | nex2  |    nex2 - number of extents after idx + count
 *    |-------|   |-------|
 */
void
xfs_iext_remove_indirect(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_extnum_t      idx,        /* index to begin removing extents */
      int         count)            /* number of extents to remove */
{
      xfs_ext_irec_t    *erp;       /* indirection array pointer */
      int         erp_idx = 0;      /* indirection array index */
      xfs_extnum_t      ext_cnt;    /* extents left to remove */
      xfs_extnum_t      ext_diff;   /* extents to remove in current list */
      xfs_extnum_t      nex1;       /* number of extents before idx */
      xfs_extnum_t      nex2;       /* extents after idx + count */
      int         nlists;           /* entries in indirection array */
      int         page_idx = idx;   /* index in target extent list */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      erp = xfs_iext_idx_to_irec(ifp,  &page_idx, &erp_idx, 0);
      ASSERT(erp != NULL);
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
      nex1 = page_idx;
      ext_cnt = count;
      while (ext_cnt) {
            nex2 = MAX((erp->er_extcount - (nex1 + ext_cnt)), 0);
            ext_diff = MIN(ext_cnt, (erp->er_extcount - nex1));
            /*
             * Check for deletion of entire list;
             * xfs_iext_irec_remove() updates extent offsets.
             */
            if (ext_diff == erp->er_extcount) {
                  xfs_iext_irec_remove(ifp, erp_idx);
                  ext_cnt -= ext_diff;
                  nex1 = 0;
                  if (ext_cnt) {
                        ASSERT(erp_idx < ifp->if_real_bytes /
                              XFS_IEXT_BUFSZ);
                        erp = &ifp->if_u1.if_ext_irec[erp_idx];
                        nex1 = 0;
                        continue;
                  } else {
                        break;
                  }
            }
            /* Move extents up (if needed) */
            if (nex2) {
                  memmove(&erp->er_extbuf[nex1],
                        &erp->er_extbuf[nex1 + ext_diff],
                        nex2 * sizeof(xfs_bmbt_rec_t));
            }
            /* Zero out rest of page */
            memset(&erp->er_extbuf[nex1 + nex2], 0, (XFS_IEXT_BUFSZ -
                  ((nex1 + nex2) * sizeof(xfs_bmbt_rec_t))));
            /* Update remaining counters */
            erp->er_extcount -= ext_diff;
            xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, -ext_diff);
            ext_cnt -= ext_diff;
            nex1 = 0;
            erp_idx++;
            erp++;
      }
      ifp->if_bytes -= count * sizeof(xfs_bmbt_rec_t);
      xfs_iext_irec_compact(ifp);
}

/*
 * Create, destroy, or resize a linear (direct) block of extents.
 */
void
xfs_iext_realloc_direct(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      int         new_size)   /* new size of extents */
{
      int         rnew_size;  /* real new size of extents */

      rnew_size = new_size;

      ASSERT(!(ifp->if_flags & XFS_IFEXTIREC) ||
            ((new_size >= 0) && (new_size <= XFS_IEXT_BUFSZ) &&
             (new_size != ifp->if_real_bytes)));

      /* Free extent records */
      if (new_size == 0) {
            xfs_iext_destroy(ifp);
      }
      /* Resize direct extent list and zero any new bytes */
      else if (ifp->if_real_bytes) {
            /* Check if extents will fit inside the inode */
            if (new_size <= XFS_INLINE_EXTS * sizeof(xfs_bmbt_rec_t)) {
                  xfs_iext_direct_to_inline(ifp, new_size /
                        (uint)sizeof(xfs_bmbt_rec_t));
                  ifp->if_bytes = new_size;
                  return;
            }
            if (!is_power_of_2(new_size)){
                  rnew_size = xfs_iroundup(new_size);
            }
            if (rnew_size != ifp->if_real_bytes) {
                  ifp->if_u1.if_extents =
                        kmem_realloc(ifp->if_u1.if_extents,
                                    rnew_size,
                                    ifp->if_real_bytes,
                                    KM_SLEEP);
            }
            if (rnew_size > ifp->if_real_bytes) {
                  memset(&ifp->if_u1.if_extents[ifp->if_bytes /
                        (uint)sizeof(xfs_bmbt_rec_t)], 0,
                        rnew_size - ifp->if_real_bytes);
            }
      }
      /*
       * Switch from the inline extent buffer to a direct
       * extent list. Be sure to include the inline extent
       * bytes in new_size.
       */
      else {
            new_size += ifp->if_bytes;
            if (!is_power_of_2(new_size)) {
                  rnew_size = xfs_iroundup(new_size);
            }
            xfs_iext_inline_to_direct(ifp, rnew_size);
      }
      ifp->if_real_bytes = rnew_size;
      ifp->if_bytes = new_size;
}

/*
 * Switch from linear (direct) extent records to inline buffer.
 */
void
xfs_iext_direct_to_inline(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_extnum_t      nextents)   /* number of extents in file */
{
      ASSERT(ifp->if_flags & XFS_IFEXTENTS);
      ASSERT(nextents <= XFS_INLINE_EXTS);
      /*
       * The inline buffer was zeroed when we switched
       * from inline to direct extent allocation mode,
       * so we don't need to clear it here.
       */
      memcpy(ifp->if_u2.if_inline_ext, ifp->if_u1.if_extents,
            nextents * sizeof(xfs_bmbt_rec_t));
      kmem_free(ifp->if_u1.if_extents, ifp->if_real_bytes);
      ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
      ifp->if_real_bytes = 0;
}

/*
 * Switch from inline buffer to linear (direct) extent records.
 * new_size should already be rounded up to the next power of 2
 * by the caller (when appropriate), so use new_size as it is.
 * However, since new_size may be rounded up, we can't update
 * if_bytes here. It is the caller's responsibility to update
 * if_bytes upon return.
 */
void
xfs_iext_inline_to_direct(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      int         new_size)   /* number of extents in file */
{
      ifp->if_u1.if_extents = kmem_alloc(new_size, KM_SLEEP);
      memset(ifp->if_u1.if_extents, 0, new_size);
      if (ifp->if_bytes) {
            memcpy(ifp->if_u1.if_extents, ifp->if_u2.if_inline_ext,
                  ifp->if_bytes);
            memset(ifp->if_u2.if_inline_ext, 0, XFS_INLINE_EXTS *
                  sizeof(xfs_bmbt_rec_t));
      }
      ifp->if_real_bytes = new_size;
}

/*
 * Resize an extent indirection array to new_size bytes.
 */
void
xfs_iext_realloc_indirect(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      int         new_size)   /* new indirection array size */
{
      int         nlists;           /* number of irec's (ex lists) */
      int         size;       /* current indirection array size */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
      size = nlists * sizeof(xfs_ext_irec_t);
      ASSERT(ifp->if_real_bytes);
      ASSERT((new_size >= 0) && (new_size != size));
      if (new_size == 0) {
            xfs_iext_destroy(ifp);
      } else {
            ifp->if_u1.if_ext_irec = (xfs_ext_irec_t *)
                  kmem_realloc(ifp->if_u1.if_ext_irec,
                        new_size, size, KM_SLEEP);
      }
}

/*
 * Switch from indirection array to linear (direct) extent allocations.
 */
void
xfs_iext_indirect_to_direct(
       xfs_ifork_t      *ifp)       /* inode fork pointer */
{
      xfs_bmbt_rec_host_t *ep;      /* extent record pointer */
      xfs_extnum_t      nextents;   /* number of extents in file */
      int         size;       /* size of file extents */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
      ASSERT(nextents <= XFS_LINEAR_EXTS);
      size = nextents * sizeof(xfs_bmbt_rec_t);

      xfs_iext_irec_compact_full(ifp);
      ASSERT(ifp->if_real_bytes == XFS_IEXT_BUFSZ);

      ep = ifp->if_u1.if_ext_irec->er_extbuf;
      kmem_free(ifp->if_u1.if_ext_irec, sizeof(xfs_ext_irec_t));
      ifp->if_flags &= ~XFS_IFEXTIREC;
      ifp->if_u1.if_extents = ep;
      ifp->if_bytes = size;
      if (nextents < XFS_LINEAR_EXTS) {
            xfs_iext_realloc_direct(ifp, size);
      }
}

/*
 * Free incore file extents.
 */
void
xfs_iext_destroy(
      xfs_ifork_t *ifp)       /* inode fork pointer */
{
      if (ifp->if_flags & XFS_IFEXTIREC) {
            int   erp_idx;
            int   nlists;

            nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
            for (erp_idx = nlists - 1; erp_idx >= 0 ; erp_idx--) {
                  xfs_iext_irec_remove(ifp, erp_idx);
            }
            ifp->if_flags &= ~XFS_IFEXTIREC;
      } else if (ifp->if_real_bytes) {
            kmem_free(ifp->if_u1.if_extents, ifp->if_real_bytes);
      } else if (ifp->if_bytes) {
            memset(ifp->if_u2.if_inline_ext, 0, XFS_INLINE_EXTS *
                  sizeof(xfs_bmbt_rec_t));
      }
      ifp->if_u1.if_extents = NULL;
      ifp->if_real_bytes = 0;
      ifp->if_bytes = 0;
}

/*
 * Return a pointer to the extent record for file system block bno.
 */
xfs_bmbt_rec_host_t *               /* pointer to found extent record */
xfs_iext_bno_to_ext(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_fileoff_t     bno,        /* block number to search for */
      xfs_extnum_t      *idxp)            /* index of target extent */
{
      xfs_bmbt_rec_host_t *base;    /* pointer to first extent */
      xfs_filblks_t     blockcount = 0;   /* number of blocks in extent */
      xfs_bmbt_rec_host_t *ep = NULL;     /* pointer to target extent */
      xfs_ext_irec_t    *erp = NULL;      /* indirection array pointer */
      int         high;       /* upper boundary in search */
      xfs_extnum_t      idx = 0;    /* index of target extent */
      int         low;        /* lower boundary in search */
      xfs_extnum_t      nextents;   /* number of file extents */
      xfs_fileoff_t     startoff = 0;     /* start offset of extent */

      nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
      if (nextents == 0) {
            *idxp = 0;
            return NULL;
      }
      low = 0;
      if (ifp->if_flags & XFS_IFEXTIREC) {
            /* Find target extent list */
            int   erp_idx = 0;
            erp = xfs_iext_bno_to_irec(ifp, bno, &erp_idx);
            base = erp->er_extbuf;
            high = erp->er_extcount - 1;
      } else {
            base = ifp->if_u1.if_extents;
            high = nextents - 1;
      }
      /* Binary search extent records */
      while (low <= high) {
            idx = (low + high) >> 1;
            ep = base + idx;
            startoff = xfs_bmbt_get_startoff(ep);
            blockcount = xfs_bmbt_get_blockcount(ep);
            if (bno < startoff) {
                  high = idx - 1;
            } else if (bno >= startoff + blockcount) {
                  low = idx + 1;
            } else {
                  /* Convert back to file-based extent index */
                  if (ifp->if_flags & XFS_IFEXTIREC) {
                        idx += erp->er_extoff;
                  }
                  *idxp = idx;
                  return ep;
            }
      }
      /* Convert back to file-based extent index */
      if (ifp->if_flags & XFS_IFEXTIREC) {
            idx += erp->er_extoff;
      }
      if (bno >= startoff + blockcount) {
            if (++idx == nextents) {
                  ep = NULL;
            } else {
                  ep = xfs_iext_get_ext(ifp, idx);
            }
      }
      *idxp = idx;
      return ep;
}

/*
 * Return a pointer to the indirection array entry containing the
 * extent record for filesystem block bno. Store the index of the
 * target irec in *erp_idxp.
 */
xfs_ext_irec_t *              /* pointer to found extent record */
xfs_iext_bno_to_irec(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_fileoff_t     bno,        /* block number to search for */
      int         *erp_idxp)  /* irec index of target ext list */
{
      xfs_ext_irec_t    *erp = NULL;      /* indirection array pointer */
      xfs_ext_irec_t    *erp_next;  /* next indirection array entry */
      int         erp_idx;    /* indirection array index */
      int         nlists;           /* number of extent irec's (lists) */
      int         high;       /* binary search upper limit */
      int         low;        /* binary search lower limit */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
      erp_idx = 0;
      low = 0;
      high = nlists - 1;
      while (low <= high) {
            erp_idx = (low + high) >> 1;
            erp = &ifp->if_u1.if_ext_irec[erp_idx];
            erp_next = erp_idx < nlists - 1 ? erp + 1 : NULL;
            if (bno < xfs_bmbt_get_startoff(erp->er_extbuf)) {
                  high = erp_idx - 1;
            } else if (erp_next && bno >=
                     xfs_bmbt_get_startoff(erp_next->er_extbuf)) {
                  low = erp_idx + 1;
            } else {
                  break;
            }
      }
      *erp_idxp = erp_idx;
      return erp;
}

/*
 * Return a pointer to the indirection array entry containing the
 * extent record at file extent index *idxp. Store the index of the
 * target irec in *erp_idxp and store the page index of the target
 * extent record in *idxp.
 */
xfs_ext_irec_t *
xfs_iext_idx_to_irec(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      xfs_extnum_t      *idxp,            /* extent index (file -> page) */
      int         *erp_idxp,  /* pointer to target irec */
      int         realloc)    /* new bytes were just added */
{
      xfs_ext_irec_t    *prev;            /* pointer to previous irec */
      xfs_ext_irec_t    *erp = NULL;      /* pointer to current irec */
      int         erp_idx;    /* indirection array index */
      int         nlists;           /* number of irec's (ex lists) */
      int         high;       /* binary search upper limit */
      int         low;        /* binary search lower limit */
      xfs_extnum_t      page_idx = *idxp; /* extent index in target list */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      ASSERT(page_idx >= 0 && page_idx <=
            ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t));
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
      erp_idx = 0;
      low = 0;
      high = nlists - 1;

      /* Binary search extent irec's */
      while (low <= high) {
            erp_idx = (low + high) >> 1;
            erp = &ifp->if_u1.if_ext_irec[erp_idx];
            prev = erp_idx > 0 ? erp - 1 : NULL;
            if (page_idx < erp->er_extoff || (page_idx == erp->er_extoff &&
                 realloc && prev && prev->er_extcount < XFS_LINEAR_EXTS)) {
                  high = erp_idx - 1;
            } else if (page_idx > erp->er_extoff + erp->er_extcount ||
                     (page_idx == erp->er_extoff + erp->er_extcount &&
                      !realloc)) {
                  low = erp_idx + 1;
            } else if (page_idx == erp->er_extoff + erp->er_extcount &&
                     erp->er_extcount == XFS_LINEAR_EXTS) {
                  ASSERT(realloc);
                  page_idx = 0;
                  erp_idx++;
                  erp = erp_idx < nlists ? erp + 1 : NULL;
                  break;
            } else {
                  page_idx -= erp->er_extoff;
                  break;
            }
      }
      *idxp = page_idx;
      *erp_idxp = erp_idx;
      return(erp);
}

/*
 * Allocate and initialize an indirection array once the space needed
 * for incore extents increases above XFS_IEXT_BUFSZ.
 */
void
xfs_iext_irec_init(
      xfs_ifork_t *ifp)       /* inode fork pointer */
{
      xfs_ext_irec_t    *erp;       /* indirection array pointer */
      xfs_extnum_t      nextents;   /* number of extents in file */

      ASSERT(!(ifp->if_flags & XFS_IFEXTIREC));
      nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
      ASSERT(nextents <= XFS_LINEAR_EXTS);

      erp = (xfs_ext_irec_t *)
            kmem_alloc(sizeof(xfs_ext_irec_t), KM_SLEEP);

      if (nextents == 0) {
            ifp->if_u1.if_extents = kmem_alloc(XFS_IEXT_BUFSZ, KM_SLEEP);
      } else if (!ifp->if_real_bytes) {
            xfs_iext_inline_to_direct(ifp, XFS_IEXT_BUFSZ);
      } else if (ifp->if_real_bytes < XFS_IEXT_BUFSZ) {
            xfs_iext_realloc_direct(ifp, XFS_IEXT_BUFSZ);
      }
      erp->er_extbuf = ifp->if_u1.if_extents;
      erp->er_extcount = nextents;
      erp->er_extoff = 0;

      ifp->if_flags |= XFS_IFEXTIREC;
      ifp->if_real_bytes = XFS_IEXT_BUFSZ;
      ifp->if_bytes = nextents * sizeof(xfs_bmbt_rec_t);
      ifp->if_u1.if_ext_irec = erp;

      return;
}

/*
 * Allocate and initialize a new entry in the indirection array.
 */
xfs_ext_irec_t *
xfs_iext_irec_new(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      int         erp_idx)    /* index for new irec */
{
      xfs_ext_irec_t    *erp;       /* indirection array pointer */
      int         i;          /* loop counter */
      int         nlists;           /* number of irec's (ex lists) */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;

      /* Resize indirection array */
      xfs_iext_realloc_indirect(ifp, ++nlists *
                          sizeof(xfs_ext_irec_t));
      /*
       * Move records down in the array so the
       * new page can use erp_idx.
       */
      erp = ifp->if_u1.if_ext_irec;
      for (i = nlists - 1; i > erp_idx; i--) {
            memmove(&erp[i], &erp[i-1], sizeof(xfs_ext_irec_t));
      }
      ASSERT(i == erp_idx);

      /* Initialize new extent record */
      erp = ifp->if_u1.if_ext_irec;
      erp[erp_idx].er_extbuf = kmem_alloc(XFS_IEXT_BUFSZ, KM_SLEEP);
      ifp->if_real_bytes = nlists * XFS_IEXT_BUFSZ;
      memset(erp[erp_idx].er_extbuf, 0, XFS_IEXT_BUFSZ);
      erp[erp_idx].er_extcount = 0;
      erp[erp_idx].er_extoff = erp_idx > 0 ?
            erp[erp_idx-1].er_extoff + erp[erp_idx-1].er_extcount : 0;
      return (&erp[erp_idx]);
}

/*
 * Remove a record from the indirection array.
 */
void
xfs_iext_irec_remove(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      int         erp_idx)    /* irec index to remove */
{
      xfs_ext_irec_t    *erp;       /* indirection array pointer */
      int         i;          /* loop counter */
      int         nlists;           /* number of irec's (ex lists) */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
      erp = &ifp->if_u1.if_ext_irec[erp_idx];
      if (erp->er_extbuf) {
            xfs_iext_irec_update_extoffs(ifp, erp_idx + 1,
                  -erp->er_extcount);
            kmem_free(erp->er_extbuf, XFS_IEXT_BUFSZ);
      }
      /* Compact extent records */
      erp = ifp->if_u1.if_ext_irec;
      for (i = erp_idx; i < nlists - 1; i++) {
            memmove(&erp[i], &erp[i+1], sizeof(xfs_ext_irec_t));
      }
      /*
       * Manually free the last extent record from the indirection
       * array.  A call to xfs_iext_realloc_indirect() with a size
       * of zero would result in a call to xfs_iext_destroy() which
       * would in turn call this function again, creating a nasty
       * infinite loop.
       */
      if (--nlists) {
            xfs_iext_realloc_indirect(ifp,
                  nlists * sizeof(xfs_ext_irec_t));
      } else {
            kmem_free(ifp->if_u1.if_ext_irec,
                  sizeof(xfs_ext_irec_t));
      }
      ifp->if_real_bytes = nlists * XFS_IEXT_BUFSZ;
}

/*
 * This is called to clean up large amounts of unused memory allocated
 * by the indirection array.  Before compacting anything though, verify
 * that the indirection array is still needed and switch back to the
 * linear extent list (or even the inline buffer) if possible.  The
 * compaction policy is as follows:
 *
 *    Full Compaction: Extents fit into a single page (or inline buffer)
 *    Full Compaction: Extents occupy less than 10% of allocated space
 * Partial Compaction: Extents occupy > 10% and < 50% of allocated space
 *      No Compaction: Extents occupy at least 50% of allocated space
 */
void
xfs_iext_irec_compact(
      xfs_ifork_t *ifp)       /* inode fork pointer */
{
      xfs_extnum_t      nextents;   /* number of extents in file */
      int         nlists;           /* number of irec's (ex lists) */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
      nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);

      if (nextents == 0) {
            xfs_iext_destroy(ifp);
      } else if (nextents <= XFS_INLINE_EXTS) {
            xfs_iext_indirect_to_direct(ifp);
            xfs_iext_direct_to_inline(ifp, nextents);
      } else if (nextents <= XFS_LINEAR_EXTS) {
            xfs_iext_indirect_to_direct(ifp);
      } else if (nextents < (nlists * XFS_LINEAR_EXTS) >> 3) {
            xfs_iext_irec_compact_full(ifp);
      } else if (nextents < (nlists * XFS_LINEAR_EXTS) >> 1) {
            xfs_iext_irec_compact_pages(ifp);
      }
}

/*
 * Combine extents from neighboring extent pages.
 */
void
xfs_iext_irec_compact_pages(
      xfs_ifork_t *ifp)       /* inode fork pointer */
{
      xfs_ext_irec_t    *erp, *erp_next;/* pointers to irec entries */
      int         erp_idx = 0;      /* indirection array index */
      int         nlists;           /* number of irec's (ex lists) */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
      while (erp_idx < nlists - 1) {
            erp = &ifp->if_u1.if_ext_irec[erp_idx];
            erp_next = erp + 1;
            if (erp_next->er_extcount <=
                (XFS_LINEAR_EXTS - erp->er_extcount)) {
                  memmove(&erp->er_extbuf[erp->er_extcount],
                        erp_next->er_extbuf, erp_next->er_extcount *
                        sizeof(xfs_bmbt_rec_t));
                  erp->er_extcount += erp_next->er_extcount;
                  /*
                   * Free page before removing extent record
                   * so er_extoffs don't get modified in
                   * xfs_iext_irec_remove.
                   */
                  kmem_free(erp_next->er_extbuf, XFS_IEXT_BUFSZ);
                  erp_next->er_extbuf = NULL;
                  xfs_iext_irec_remove(ifp, erp_idx + 1);
                  nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
            } else {
                  erp_idx++;
            }
      }
}

/*
 * Fully compact the extent records managed by the indirection array.
 */
void
xfs_iext_irec_compact_full(
      xfs_ifork_t *ifp)             /* inode fork pointer */
{
      xfs_bmbt_rec_host_t *ep, *ep_next;  /* extent record pointers */
      xfs_ext_irec_t    *erp, *erp_next;  /* extent irec pointers */
      int         erp_idx = 0;            /* extent irec index */
      int         ext_avail;        /* empty entries in ex list */
      int         ext_diff;         /* number of exts to add */
      int         nlists;                 /* number of irec's (ex lists) */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
      erp = ifp->if_u1.if_ext_irec;
      ep = &erp->er_extbuf[erp->er_extcount];
      erp_next = erp + 1;
      ep_next = erp_next->er_extbuf;
      while (erp_idx < nlists - 1) {
            ext_avail = XFS_LINEAR_EXTS - erp->er_extcount;
            ext_diff = MIN(ext_avail, erp_next->er_extcount);
            memcpy(ep, ep_next, ext_diff * sizeof(xfs_bmbt_rec_t));
            erp->er_extcount += ext_diff;
            erp_next->er_extcount -= ext_diff;
            /* Remove next page */
            if (erp_next->er_extcount == 0) {
                  /*
                   * Free page before removing extent record
                   * so er_extoffs don't get modified in
                   * xfs_iext_irec_remove.
                   */
                  kmem_free(erp_next->er_extbuf,
                        erp_next->er_extcount * sizeof(xfs_bmbt_rec_t));
                  erp_next->er_extbuf = NULL;
                  xfs_iext_irec_remove(ifp, erp_idx + 1);
                  erp = &ifp->if_u1.if_ext_irec[erp_idx];
                  nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
            /* Update next page */
            } else {
                  /* Move rest of page up to become next new page */
                  memmove(erp_next->er_extbuf, ep_next,
                        erp_next->er_extcount * sizeof(xfs_bmbt_rec_t));
                  ep_next = erp_next->er_extbuf;
                  memset(&ep_next[erp_next->er_extcount], 0,
                        (XFS_LINEAR_EXTS - erp_next->er_extcount) *
                        sizeof(xfs_bmbt_rec_t));
            }
            if (erp->er_extcount == XFS_LINEAR_EXTS) {
                  erp_idx++;
                  if (erp_idx < nlists)
                        erp = &ifp->if_u1.if_ext_irec[erp_idx];
                  else
                        break;
            }
            ep = &erp->er_extbuf[erp->er_extcount];
            erp_next = erp + 1;
            ep_next = erp_next->er_extbuf;
      }
}

/*
 * This is called to update the er_extoff field in the indirection
 * array when extents have been added or removed from one of the
 * extent lists. erp_idx contains the irec index to begin updating
 * at and ext_diff contains the number of extents that were added
 * or removed.
 */
void
xfs_iext_irec_update_extoffs(
      xfs_ifork_t *ifp,       /* inode fork pointer */
      int         erp_idx,    /* irec index to update */
      int         ext_diff)   /* number of new extents */
{
      int         i;          /* loop counter */
      int         nlists;           /* number of irec's (ex lists */

      ASSERT(ifp->if_flags & XFS_IFEXTIREC);
      nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
      for (i = erp_idx; i < nlists; i++) {
            ifp->if_u1.if_ext_irec[i].er_extoff += ext_diff;
      }
}

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