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xfs_attr_leaf.c

/*
 * Copyright (c) 2000-2005 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_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_alloc.h"
#include "xfs_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_error.h"

/*
 * xfs_attr_leaf.c
 *
 * Routines to implement leaf blocks of attributes as Btrees of hashed names.
 */

/*========================================================================
 * Function prototypes for the kernel.
 *========================================================================*/

/*
 * Routines used for growing the Btree.
 */
STATIC int xfs_attr_leaf_create(xfs_da_args_t *args, xfs_dablk_t which_block,
                            xfs_dabuf_t **bpp);
STATIC int xfs_attr_leaf_add_work(xfs_dabuf_t *leaf_buffer, xfs_da_args_t *args,
                                    int freemap_index);
STATIC void xfs_attr_leaf_compact(xfs_trans_t *trans, xfs_dabuf_t *leaf_buffer);
STATIC void xfs_attr_leaf_rebalance(xfs_da_state_t *state,
                                       xfs_da_state_blk_t *blk1,
                                       xfs_da_state_blk_t *blk2);
STATIC int xfs_attr_leaf_figure_balance(xfs_da_state_t *state,
                                 xfs_da_state_blk_t *leaf_blk_1,
                                 xfs_da_state_blk_t *leaf_blk_2,
                                 int *number_entries_in_blk1,
                                 int *number_usedbytes_in_blk1);

/*
 * Routines used for shrinking the Btree.
 */
STATIC int xfs_attr_node_inactive(xfs_trans_t **trans, xfs_inode_t *dp,
                          xfs_dabuf_t *bp, int level);
STATIC int xfs_attr_leaf_inactive(xfs_trans_t **trans, xfs_inode_t *dp,
                          xfs_dabuf_t *bp);
STATIC int xfs_attr_leaf_freextent(xfs_trans_t **trans, xfs_inode_t *dp,
                           xfs_dablk_t blkno, int blkcnt);

/*
 * Utility routines.
 */
STATIC void xfs_attr_leaf_moveents(xfs_attr_leafblock_t *src_leaf,
                               int src_start,
                               xfs_attr_leafblock_t *dst_leaf,
                               int dst_start, int move_count,
                               xfs_mount_t *mp);
STATIC int xfs_attr_leaf_entsize(xfs_attr_leafblock_t *leaf, int index);

/*========================================================================
 * Namespace helper routines
 *========================================================================*/

/*
 * If namespace bits don't match return 0.
 * If all match then return 1.
 */
STATIC_INLINE int
xfs_attr_namesp_match(int arg_flags, int ondisk_flags)
{
      return XFS_ATTR_NSP_ONDISK(ondisk_flags) == XFS_ATTR_NSP_ARGS_TO_ONDISK(arg_flags);
}


/*========================================================================
 * External routines when attribute fork size < XFS_LITINO(mp).
 *========================================================================*/

/*
 * Query whether the requested number of additional bytes of extended
 * attribute space will be able to fit inline.
 * Returns zero if not, else the di_forkoff fork offset to be used in the
 * literal area for attribute data once the new bytes have been added.
 *
 * di_forkoff must be 8 byte aligned, hence is stored as a >>3 value;
 * special case for dev/uuid inodes, they have fixed size data forks.
 */
int
xfs_attr_shortform_bytesfit(xfs_inode_t *dp, int bytes)
{
      int offset;
      int minforkoff;   /* lower limit on valid forkoff locations */
      int maxforkoff;   /* upper limit on valid forkoff locations */
      int dsize;  
      xfs_mount_t *mp = dp->i_mount;

      offset = (XFS_LITINO(mp) - bytes) >> 3; /* rounded down */

      switch (dp->i_d.di_format) {
      case XFS_DINODE_FMT_DEV:
            minforkoff = roundup(sizeof(xfs_dev_t), 8) >> 3;
            return (offset >= minforkoff) ? minforkoff : 0;
      case XFS_DINODE_FMT_UUID:
            minforkoff = roundup(sizeof(uuid_t), 8) >> 3;
            return (offset >= minforkoff) ? minforkoff : 0;
      }

      if (!(mp->m_flags & XFS_MOUNT_ATTR2)) {
            if (bytes <= XFS_IFORK_ASIZE(dp))
                  return dp->i_d.di_forkoff;
            return 0;
      }

      dsize = dp->i_df.if_bytes;
      
      switch (dp->i_d.di_format) {
      case XFS_DINODE_FMT_EXTENTS:
            /* 
             * If there is no attr fork and the data fork is extents, 
             * determine if creating the default attr fork will result 
             * in the extents form migrating to btree. If so, the 
             * minimum offset only needs to be the space required for 
             * the btree root.
             */ 
            if (!dp->i_d.di_forkoff && dp->i_df.if_bytes >
                xfs_default_attroffset(dp))
                  dsize = XFS_BMDR_SPACE_CALC(MINDBTPTRS);
            break;
            
      case XFS_DINODE_FMT_BTREE:
            /*
             * If have data btree then keep forkoff if we have one,
             * otherwise we are adding a new attr, so then we set 
             * minforkoff to where the btree root can finish so we have 
             * plenty of room for attrs
             */
            if (dp->i_d.di_forkoff) {
                  if (offset < dp->i_d.di_forkoff) 
                        return 0;
                  else 
                        return dp->i_d.di_forkoff;
            } else
                  dsize = XFS_BMAP_BROOT_SPACE(dp->i_df.if_broot);
            break;
      }
      
      /* 
       * A data fork btree root must have space for at least 
       * MINDBTPTRS key/ptr pairs if the data fork is small or empty.
       */
      minforkoff = MAX(dsize, XFS_BMDR_SPACE_CALC(MINDBTPTRS));
      minforkoff = roundup(minforkoff, 8) >> 3;

      /* attr fork btree root can have at least this many key/ptr pairs */
      maxforkoff = XFS_LITINO(mp) - XFS_BMDR_SPACE_CALC(MINABTPTRS);
      maxforkoff = maxforkoff >> 3; /* rounded down */

      if (offset >= minforkoff && offset < maxforkoff)
            return offset;
      if (offset >= maxforkoff)
            return maxforkoff;
      return 0;
}

/*
 * Switch on the ATTR2 superblock bit (implies also FEATURES2)
 */
STATIC void
xfs_sbversion_add_attr2(xfs_mount_t *mp, xfs_trans_t *tp)
{
      if ((mp->m_flags & XFS_MOUNT_ATTR2) &&
          !(xfs_sb_version_hasattr2(&mp->m_sb))) {
            spin_lock(&mp->m_sb_lock);
            if (!xfs_sb_version_hasattr2(&mp->m_sb)) {
                  xfs_sb_version_addattr2(&mp->m_sb);
                  spin_unlock(&mp->m_sb_lock);
                  xfs_mod_sb(tp, XFS_SB_VERSIONNUM | XFS_SB_FEATURES2);
            } else
                  spin_unlock(&mp->m_sb_lock);
      }
}

/*
 * Create the initial contents of a shortform attribute list.
 */
void
xfs_attr_shortform_create(xfs_da_args_t *args)
{
      xfs_attr_sf_hdr_t *hdr;
      xfs_inode_t *dp;
      xfs_ifork_t *ifp;

      dp = args->dp;
      ASSERT(dp != NULL);
      ifp = dp->i_afp;
      ASSERT(ifp != NULL);
      ASSERT(ifp->if_bytes == 0);
      if (dp->i_d.di_aformat == XFS_DINODE_FMT_EXTENTS) {
            ifp->if_flags &= ~XFS_IFEXTENTS;    /* just in case */
            dp->i_d.di_aformat = XFS_DINODE_FMT_LOCAL;
            ifp->if_flags |= XFS_IFINLINE;
      } else {
            ASSERT(ifp->if_flags & XFS_IFINLINE);
      }
      xfs_idata_realloc(dp, sizeof(*hdr), XFS_ATTR_FORK);
      hdr = (xfs_attr_sf_hdr_t *)ifp->if_u1.if_data;
      hdr->count = 0;
      hdr->totsize = cpu_to_be16(sizeof(*hdr));
      xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_ADATA);
}

/*
 * Add a name/value pair to the shortform attribute list.
 * Overflow from the inode has already been checked for.
 */
void
xfs_attr_shortform_add(xfs_da_args_t *args, int forkoff)
{
      xfs_attr_shortform_t *sf;
      xfs_attr_sf_entry_t *sfe;
      int i, offset, size;
      xfs_mount_t *mp;
      xfs_inode_t *dp;
      xfs_ifork_t *ifp;

      dp = args->dp;
      mp = dp->i_mount;
      dp->i_d.di_forkoff = forkoff;
      dp->i_df.if_ext_max =
            XFS_IFORK_DSIZE(dp) / (uint)sizeof(xfs_bmbt_rec_t);
      dp->i_afp->if_ext_max =
            XFS_IFORK_ASIZE(dp) / (uint)sizeof(xfs_bmbt_rec_t);

      ifp = dp->i_afp;
      ASSERT(ifp->if_flags & XFS_IFINLINE);
      sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
      sfe = &sf->list[0];
      for (i = 0; i < sf->hdr.count; sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
#ifdef DEBUG
            if (sfe->namelen != args->namelen)
                  continue;
            if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
                  continue;
            if (!xfs_attr_namesp_match(args->flags, sfe->flags))
                  continue;
            ASSERT(0);
#endif
      }

      offset = (char *)sfe - (char *)sf;
      size = XFS_ATTR_SF_ENTSIZE_BYNAME(args->namelen, args->valuelen);
      xfs_idata_realloc(dp, size, XFS_ATTR_FORK);
      sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
      sfe = (xfs_attr_sf_entry_t *)((char *)sf + offset);

      sfe->namelen = args->namelen;
      sfe->valuelen = args->valuelen;
      sfe->flags = XFS_ATTR_NSP_ARGS_TO_ONDISK(args->flags);
      memcpy(sfe->nameval, args->name, args->namelen);
      memcpy(&sfe->nameval[args->namelen], args->value, args->valuelen);
      sf->hdr.count++;
      be16_add_cpu(&sf->hdr.totsize, size);
      xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_ADATA);

      xfs_sbversion_add_attr2(mp, args->trans);
}

/*
 * After the last attribute is removed revert to original inode format,
 * making all literal area available to the data fork once more.
 */
STATIC void
xfs_attr_fork_reset(
      struct xfs_inode  *ip,
      struct xfs_trans  *tp)
{
      xfs_idestroy_fork(ip, XFS_ATTR_FORK);
      ip->i_d.di_forkoff = 0;
      ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;

      ASSERT(ip->i_d.di_anextents == 0);
      ASSERT(ip->i_afp == NULL);

      ip->i_df.if_ext_max = XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t);
      xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
}

/*
 * Remove an attribute from the shortform attribute list structure.
 */
int
xfs_attr_shortform_remove(xfs_da_args_t *args)
{
      xfs_attr_shortform_t *sf;
      xfs_attr_sf_entry_t *sfe;
      int base, size=0, end, totsize, i;
      xfs_mount_t *mp;
      xfs_inode_t *dp;

      dp = args->dp;
      mp = dp->i_mount;
      base = sizeof(xfs_attr_sf_hdr_t);
      sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
      sfe = &sf->list[0];
      end = sf->hdr.count;
      for (i = 0; i < end; sfe = XFS_ATTR_SF_NEXTENTRY(sfe),
                              base += size, i++) {
            size = XFS_ATTR_SF_ENTSIZE(sfe);
            if (sfe->namelen != args->namelen)
                  continue;
            if (memcmp(sfe->nameval, args->name, args->namelen) != 0)
                  continue;
            if (!xfs_attr_namesp_match(args->flags, sfe->flags))
                  continue;
            break;
      }
      if (i == end)
            return(XFS_ERROR(ENOATTR));

      /*
       * Fix up the attribute fork data, covering the hole
       */
      end = base + size;
      totsize = be16_to_cpu(sf->hdr.totsize);
      if (end != totsize)
            memmove(&((char *)sf)[base], &((char *)sf)[end], totsize - end);
      sf->hdr.count--;
      be16_add_cpu(&sf->hdr.totsize, -size);

      /*
       * Fix up the start offset of the attribute fork
       */
      totsize -= size;
      if (totsize == sizeof(xfs_attr_sf_hdr_t) &&
          (mp->m_flags & XFS_MOUNT_ATTR2) &&
          (dp->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
          !(args->op_flags & XFS_DA_OP_ADDNAME)) {
            xfs_attr_fork_reset(dp, args->trans);
      } else {
            xfs_idata_realloc(dp, -size, XFS_ATTR_FORK);
            dp->i_d.di_forkoff = xfs_attr_shortform_bytesfit(dp, totsize);
            ASSERT(dp->i_d.di_forkoff);
            ASSERT(totsize > sizeof(xfs_attr_sf_hdr_t) ||
                        (args->op_flags & XFS_DA_OP_ADDNAME) ||
                        !(mp->m_flags & XFS_MOUNT_ATTR2) ||
                        dp->i_d.di_format == XFS_DINODE_FMT_BTREE);
            dp->i_afp->if_ext_max =
                  XFS_IFORK_ASIZE(dp) / (uint)sizeof(xfs_bmbt_rec_t);
            dp->i_df.if_ext_max =
                  XFS_IFORK_DSIZE(dp) / (uint)sizeof(xfs_bmbt_rec_t);
            xfs_trans_log_inode(args->trans, dp,
                              XFS_ILOG_CORE | XFS_ILOG_ADATA);
      }

      xfs_sbversion_add_attr2(mp, args->trans);

      return(0);
}

/*
 * Look up a name in a shortform attribute list structure.
 */
/*ARGSUSED*/
int
xfs_attr_shortform_lookup(xfs_da_args_t *args)
{
      xfs_attr_shortform_t *sf;
      xfs_attr_sf_entry_t *sfe;
      int i;
      xfs_ifork_t *ifp;

      ifp = args->dp->i_afp;
      ASSERT(ifp->if_flags & XFS_IFINLINE);
      sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
      sfe = &sf->list[0];
      for (i = 0; i < sf->hdr.count;
                        sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
            if (sfe->namelen != args->namelen)
                  continue;
            if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
                  continue;
            if (!xfs_attr_namesp_match(args->flags, sfe->flags))
                  continue;
            return(XFS_ERROR(EEXIST));
      }
      return(XFS_ERROR(ENOATTR));
}

/*
 * Look up a name in a shortform attribute list structure.
 */
/*ARGSUSED*/
int
xfs_attr_shortform_getvalue(xfs_da_args_t *args)
{
      xfs_attr_shortform_t *sf;
      xfs_attr_sf_entry_t *sfe;
      int i;

      ASSERT(args->dp->i_d.di_aformat == XFS_IFINLINE);
      sf = (xfs_attr_shortform_t *)args->dp->i_afp->if_u1.if_data;
      sfe = &sf->list[0];
      for (i = 0; i < sf->hdr.count;
                        sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
            if (sfe->namelen != args->namelen)
                  continue;
            if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
                  continue;
            if (!xfs_attr_namesp_match(args->flags, sfe->flags))
                  continue;
            if (args->flags & ATTR_KERNOVAL) {
                  args->valuelen = sfe->valuelen;
                  return(XFS_ERROR(EEXIST));
            }
            if (args->valuelen < sfe->valuelen) {
                  args->valuelen = sfe->valuelen;
                  return(XFS_ERROR(ERANGE));
            }
            args->valuelen = sfe->valuelen;
            memcpy(args->value, &sfe->nameval[args->namelen],
                                        args->valuelen);
            return(XFS_ERROR(EEXIST));
      }
      return(XFS_ERROR(ENOATTR));
}

/*
 * Convert from using the shortform to the leaf.
 */
int
xfs_attr_shortform_to_leaf(xfs_da_args_t *args)
{
      xfs_inode_t *dp;
      xfs_attr_shortform_t *sf;
      xfs_attr_sf_entry_t *sfe;
      xfs_da_args_t nargs;
      char *tmpbuffer;
      int error, i, size;
      xfs_dablk_t blkno;
      xfs_dabuf_t *bp;
      xfs_ifork_t *ifp;

      dp = args->dp;
      ifp = dp->i_afp;
      sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
      size = be16_to_cpu(sf->hdr.totsize);
      tmpbuffer = kmem_alloc(size, KM_SLEEP);
      ASSERT(tmpbuffer != NULL);
      memcpy(tmpbuffer, ifp->if_u1.if_data, size);
      sf = (xfs_attr_shortform_t *)tmpbuffer;

      xfs_idata_realloc(dp, -size, XFS_ATTR_FORK);
      bp = NULL;
      error = xfs_da_grow_inode(args, &blkno);
      if (error) {
            /*
             * If we hit an IO error middle of the transaction inside
             * grow_inode(), we may have inconsistent data. Bail out.
             */
            if (error == EIO)
                  goto out;
            xfs_idata_realloc(dp, size, XFS_ATTR_FORK);     /* try to put */
            memcpy(ifp->if_u1.if_data, tmpbuffer, size);    /* it back */
            goto out;
      }

      ASSERT(blkno == 0);
      error = xfs_attr_leaf_create(args, blkno, &bp);
      if (error) {
            error = xfs_da_shrink_inode(args, 0, bp);
            bp = NULL;
            if (error)
                  goto out;
            xfs_idata_realloc(dp, size, XFS_ATTR_FORK);     /* try to put */
            memcpy(ifp->if_u1.if_data, tmpbuffer, size);    /* it back */
            goto out;
      }

      memset((char *)&nargs, 0, sizeof(nargs));
      nargs.dp = dp;
      nargs.firstblock = args->firstblock;
      nargs.flist = args->flist;
      nargs.total = args->total;
      nargs.whichfork = XFS_ATTR_FORK;
      nargs.trans = args->trans;
      nargs.op_flags = XFS_DA_OP_OKNOENT;

      sfe = &sf->list[0];
      for (i = 0; i < sf->hdr.count; i++) {
            nargs.name = (char *)sfe->nameval;
            nargs.namelen = sfe->namelen;
            nargs.value = (char *)&sfe->nameval[nargs.namelen];
            nargs.valuelen = sfe->valuelen;
            nargs.hashval = xfs_da_hashname((char *)sfe->nameval,
                                    sfe->namelen);
            nargs.flags = XFS_ATTR_NSP_ONDISK_TO_ARGS(sfe->flags);
            error = xfs_attr_leaf_lookup_int(bp, &nargs); /* set a->index */
            ASSERT(error == ENOATTR);
            error = xfs_attr_leaf_add(bp, &nargs);
            ASSERT(error != ENOSPC);
            if (error)
                  goto out;
            sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
      }
      error = 0;

out:
      if(bp)
            xfs_da_buf_done(bp);
      kmem_free(tmpbuffer);
      return(error);
}

STATIC int
xfs_attr_shortform_compare(const void *a, const void *b)
{
      xfs_attr_sf_sort_t *sa, *sb;

      sa = (xfs_attr_sf_sort_t *)a;
      sb = (xfs_attr_sf_sort_t *)b;
      if (sa->hash < sb->hash) {
            return(-1);
      } else if (sa->hash > sb->hash) {
            return(1);
      } else {
            return(sa->entno - sb->entno);
      }
}


#define XFS_ISRESET_CURSOR(cursor) \
      (!((cursor)->initted) && !((cursor)->hashval) && \
       !((cursor)->blkno) && !((cursor)->offset))
/*
 * Copy out entries of shortform attribute lists for attr_list().
 * Shortform attribute lists are not stored in hashval sorted order.
 * If the output buffer is not large enough to hold them all, then we
 * we have to calculate each entries' hashvalue and sort them before
 * we can begin returning them to the user.
 */
/*ARGSUSED*/
int
xfs_attr_shortform_list(xfs_attr_list_context_t *context)
{
      attrlist_cursor_kern_t *cursor;
      xfs_attr_sf_sort_t *sbuf, *sbp;
      xfs_attr_shortform_t *sf;
      xfs_attr_sf_entry_t *sfe;
      xfs_inode_t *dp;
      int sbsize, nsbuf, count, i;
      int error;

      ASSERT(context != NULL);
      dp = context->dp;
      ASSERT(dp != NULL);
      ASSERT(dp->i_afp != NULL);
      sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
      ASSERT(sf != NULL);
      if (!sf->hdr.count)
            return(0);
      cursor = context->cursor;
      ASSERT(cursor != NULL);

      xfs_attr_trace_l_c("sf start", context);

      /*
       * If the buffer is large enough and the cursor is at the start,
       * do not bother with sorting since we will return everything in
       * one buffer and another call using the cursor won't need to be
       * made.
       * Note the generous fudge factor of 16 overhead bytes per entry.
       * If bufsize is zero then put_listent must be a search function
       * and can just scan through what we have.
       */
      if (context->bufsize == 0 ||
          (XFS_ISRESET_CURSOR(cursor) &&
             (dp->i_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
            for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
                  error = context->put_listent(context,
                                 sfe->flags,
                                 (char *)sfe->nameval,
                                 (int)sfe->namelen,
                                 (int)sfe->valuelen,
                                 (char*)&sfe->nameval[sfe->namelen]);

                  /*
                   * Either search callback finished early or
                   * didn't fit it all in the buffer after all.
                   */
                  if (context->seen_enough)
                        break;

                  if (error)
                        return error;
                  sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
            }
            xfs_attr_trace_l_c("sf big-gulp", context);
            return(0);
      }

      /* do no more for a search callback */
      if (context->bufsize == 0)
            return 0;

      /*
       * It didn't all fit, so we have to sort everything on hashval.
       */
      sbsize = sf->hdr.count * sizeof(*sbuf);
      sbp = sbuf = kmem_alloc(sbsize, KM_SLEEP);

      /*
       * Scan the attribute list for the rest of the entries, storing
       * the relevant info from only those that match into a buffer.
       */
      nsbuf = 0;
      for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
            if (unlikely(
                ((char *)sfe < (char *)sf) ||
                ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
                  XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
                                   XFS_ERRLEVEL_LOW,
                                   context->dp->i_mount, sfe);
                  xfs_attr_trace_l_c("sf corrupted", context);
                  kmem_free(sbuf);
                  return XFS_ERROR(EFSCORRUPTED);
            }

            sbp->entno = i;
            sbp->hash = xfs_da_hashname((char *)sfe->nameval, sfe->namelen);
            sbp->name = (char *)sfe->nameval;
            sbp->namelen = sfe->namelen;
            /* These are bytes, and both on-disk, don't endian-flip */
            sbp->valuelen = sfe->valuelen;
            sbp->flags = sfe->flags;
            sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
            sbp++;
            nsbuf++;
      }

      /*
       * Sort the entries on hash then entno.
       */
      xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);

      /*
       * Re-find our place IN THE SORTED LIST.
       */
      count = 0;
      cursor->initted = 1;
      cursor->blkno = 0;
      for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
            if (sbp->hash == cursor->hashval) {
                  if (cursor->offset == count) {
                        break;
                  }
                  count++;
            } else if (sbp->hash > cursor->hashval) {
                  break;
            }
      }
      if (i == nsbuf) {
            kmem_free(sbuf);
            xfs_attr_trace_l_c("blk end", context);
            return(0);
      }

      /*
       * Loop putting entries into the user buffer.
       */
      for ( ; i < nsbuf; i++, sbp++) {
            if (cursor->hashval != sbp->hash) {
                  cursor->hashval = sbp->hash;
                  cursor->offset = 0;
            }
            error = context->put_listent(context,
                              sbp->flags,
                              sbp->name,
                              sbp->namelen,
                              sbp->valuelen,
                              &sbp->name[sbp->namelen]);
            if (error)
                  return error;
            if (context->seen_enough)
                  break;
            cursor->offset++;
      }

      kmem_free(sbuf);
      xfs_attr_trace_l_c("sf E-O-F", context);
      return(0);
}

/*
 * Check a leaf attribute block to see if all the entries would fit into
 * a shortform attribute list.
 */
int
xfs_attr_shortform_allfit(xfs_dabuf_t *bp, xfs_inode_t *dp)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_entry_t *entry;
      xfs_attr_leaf_name_local_t *name_loc;
      int bytes, i;

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);

      entry = &leaf->entries[0];
      bytes = sizeof(struct xfs_attr_sf_hdr);
      for (i = 0; i < be16_to_cpu(leaf->hdr.count); entry++, i++) {
            if (entry->flags & XFS_ATTR_INCOMPLETE)
                  continue;         /* don't copy partial entries */
            if (!(entry->flags & XFS_ATTR_LOCAL))
                  return(0);
            name_loc = xfs_attr_leaf_name_local(leaf, i);
            if (name_loc->namelen >= XFS_ATTR_SF_ENTSIZE_MAX)
                  return(0);
            if (be16_to_cpu(name_loc->valuelen) >= XFS_ATTR_SF_ENTSIZE_MAX)
                  return(0);
            bytes += sizeof(struct xfs_attr_sf_entry)-1
                        + name_loc->namelen
                        + be16_to_cpu(name_loc->valuelen);
      }
      if ((dp->i_mount->m_flags & XFS_MOUNT_ATTR2) &&
          (dp->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
          (bytes == sizeof(struct xfs_attr_sf_hdr)))
            return(-1);
      return(xfs_attr_shortform_bytesfit(dp, bytes));
}

/*
 * Convert a leaf attribute list to shortform attribute list
 */
int
xfs_attr_leaf_to_shortform(xfs_dabuf_t *bp, xfs_da_args_t *args, int forkoff)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_entry_t *entry;
      xfs_attr_leaf_name_local_t *name_loc;
      xfs_da_args_t nargs;
      xfs_inode_t *dp;
      char *tmpbuffer;
      int error, i;

      dp = args->dp;
      tmpbuffer = kmem_alloc(XFS_LBSIZE(dp->i_mount), KM_SLEEP);
      ASSERT(tmpbuffer != NULL);

      ASSERT(bp != NULL);
      memcpy(tmpbuffer, bp->data, XFS_LBSIZE(dp->i_mount));
      leaf = (xfs_attr_leafblock_t *)tmpbuffer;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      memset(bp->data, 0, XFS_LBSIZE(dp->i_mount));

      /*
       * Clean out the prior contents of the attribute list.
       */
      error = xfs_da_shrink_inode(args, 0, bp);
      if (error)
            goto out;

      if (forkoff == -1) {
            ASSERT(dp->i_mount->m_flags & XFS_MOUNT_ATTR2);
            ASSERT(dp->i_d.di_format != XFS_DINODE_FMT_BTREE);
            xfs_attr_fork_reset(dp, args->trans);
            goto out;
      }

      xfs_attr_shortform_create(args);

      /*
       * Copy the attributes
       */
      memset((char *)&nargs, 0, sizeof(nargs));
      nargs.dp = dp;
      nargs.firstblock = args->firstblock;
      nargs.flist = args->flist;
      nargs.total = args->total;
      nargs.whichfork = XFS_ATTR_FORK;
      nargs.trans = args->trans;
      nargs.op_flags = XFS_DA_OP_OKNOENT;
      entry = &leaf->entries[0];
      for (i = 0; i < be16_to_cpu(leaf->hdr.count); entry++, i++) {
            if (entry->flags & XFS_ATTR_INCOMPLETE)
                  continue;   /* don't copy partial entries */
            if (!entry->nameidx)
                  continue;
            ASSERT(entry->flags & XFS_ATTR_LOCAL);
            name_loc = xfs_attr_leaf_name_local(leaf, i);
            nargs.name = (char *)name_loc->nameval;
            nargs.namelen = name_loc->namelen;
            nargs.value = (char *)&name_loc->nameval[nargs.namelen];
            nargs.valuelen = be16_to_cpu(name_loc->valuelen);
            nargs.hashval = be32_to_cpu(entry->hashval);
            nargs.flags = XFS_ATTR_NSP_ONDISK_TO_ARGS(entry->flags);
            xfs_attr_shortform_add(&nargs, forkoff);
      }
      error = 0;

out:
      kmem_free(tmpbuffer);
      return(error);
}

/*
 * Convert from using a single leaf to a root node and a leaf.
 */
int
xfs_attr_leaf_to_node(xfs_da_args_t *args)
{
      xfs_attr_leafblock_t *leaf;
      xfs_da_intnode_t *node;
      xfs_inode_t *dp;
      xfs_dabuf_t *bp1, *bp2;
      xfs_dablk_t blkno;
      int error;

      dp = args->dp;
      bp1 = bp2 = NULL;
      error = xfs_da_grow_inode(args, &blkno);
      if (error)
            goto out;
      error = xfs_da_read_buf(args->trans, args->dp, 0, -1, &bp1,
                                   XFS_ATTR_FORK);
      if (error)
            goto out;
      ASSERT(bp1 != NULL);
      bp2 = NULL;
      error = xfs_da_get_buf(args->trans, args->dp, blkno, -1, &bp2,
                                  XFS_ATTR_FORK);
      if (error)
            goto out;
      ASSERT(bp2 != NULL);
      memcpy(bp2->data, bp1->data, XFS_LBSIZE(dp->i_mount));
      xfs_da_buf_done(bp1);
      bp1 = NULL;
      xfs_da_log_buf(args->trans, bp2, 0, XFS_LBSIZE(dp->i_mount) - 1);

      /*
       * Set up the new root node.
       */
      error = xfs_da_node_create(args, 0, 1, &bp1, XFS_ATTR_FORK);
      if (error)
            goto out;
      node = bp1->data;
      leaf = bp2->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      /* both on-disk, don't endian-flip twice */
      node->btree[0].hashval =
            leaf->entries[be16_to_cpu(leaf->hdr.count)-1 ].hashval;
      node->btree[0].before = cpu_to_be32(blkno);
      node->hdr.count = cpu_to_be16(1);
      xfs_da_log_buf(args->trans, bp1, 0, XFS_LBSIZE(dp->i_mount) - 1);
      error = 0;
out:
      if (bp1)
            xfs_da_buf_done(bp1);
      if (bp2)
            xfs_da_buf_done(bp2);
      return(error);
}


/*========================================================================
 * Routines used for growing the Btree.
 *========================================================================*/

/*
 * Create the initial contents of a leaf attribute list
 * or a leaf in a node attribute list.
 */
STATIC int
xfs_attr_leaf_create(xfs_da_args_t *args, xfs_dablk_t blkno, xfs_dabuf_t **bpp)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_hdr_t *hdr;
      xfs_inode_t *dp;
      xfs_dabuf_t *bp;
      int error;

      dp = args->dp;
      ASSERT(dp != NULL);
      error = xfs_da_get_buf(args->trans, args->dp, blkno, -1, &bp,
                                  XFS_ATTR_FORK);
      if (error)
            return(error);
      ASSERT(bp != NULL);
      leaf = bp->data;
      memset((char *)leaf, 0, XFS_LBSIZE(dp->i_mount));
      hdr = &leaf->hdr;
      hdr->info.magic = cpu_to_be16(XFS_ATTR_LEAF_MAGIC);
      hdr->firstused = cpu_to_be16(XFS_LBSIZE(dp->i_mount));
      if (!hdr->firstused) {
            hdr->firstused = cpu_to_be16(
                  XFS_LBSIZE(dp->i_mount) - XFS_ATTR_LEAF_NAME_ALIGN);
      }

      hdr->freemap[0].base = cpu_to_be16(sizeof(xfs_attr_leaf_hdr_t));
      hdr->freemap[0].size = cpu_to_be16(be16_to_cpu(hdr->firstused) -
                                 sizeof(xfs_attr_leaf_hdr_t));

      xfs_da_log_buf(args->trans, bp, 0, XFS_LBSIZE(dp->i_mount) - 1);

      *bpp = bp;
      return(0);
}

/*
 * Split the leaf node, rebalance, then add the new entry.
 */
int
xfs_attr_leaf_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
                           xfs_da_state_blk_t *newblk)
{
      xfs_dablk_t blkno;
      int error;

      /*
       * Allocate space for a new leaf node.
       */
      ASSERT(oldblk->magic == XFS_ATTR_LEAF_MAGIC);
      error = xfs_da_grow_inode(state->args, &blkno);
      if (error)
            return(error);
      error = xfs_attr_leaf_create(state->args, blkno, &newblk->bp);
      if (error)
            return(error);
      newblk->blkno = blkno;
      newblk->magic = XFS_ATTR_LEAF_MAGIC;

      /*
       * Rebalance the entries across the two leaves.
       * NOTE: rebalance() currently depends on the 2nd block being empty.
       */
      xfs_attr_leaf_rebalance(state, oldblk, newblk);
      error = xfs_da_blk_link(state, oldblk, newblk);
      if (error)
            return(error);

      /*
       * Save info on "old" attribute for "atomic rename" ops, leaf_add()
       * modifies the index/blkno/rmtblk/rmtblkcnt fields to show the
       * "new" attrs info.  Will need the "old" info to remove it later.
       *
       * Insert the "new" entry in the correct block.
       */
      if (state->inleaf)
            error = xfs_attr_leaf_add(oldblk->bp, state->args);
      else
            error = xfs_attr_leaf_add(newblk->bp, state->args);

      /*
       * Update last hashval in each block since we added the name.
       */
      oldblk->hashval = xfs_attr_leaf_lasthash(oldblk->bp, NULL);
      newblk->hashval = xfs_attr_leaf_lasthash(newblk->bp, NULL);
      return(error);
}

/*
 * Add a name to the leaf attribute list structure.
 */
int
xfs_attr_leaf_add(xfs_dabuf_t *bp, xfs_da_args_t *args)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_hdr_t *hdr;
      xfs_attr_leaf_map_t *map;
      int tablesize, entsize, sum, tmp, i;

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT((args->index >= 0)
            && (args->index <= be16_to_cpu(leaf->hdr.count)));
      hdr = &leaf->hdr;
      entsize = xfs_attr_leaf_newentsize(args->namelen, args->valuelen,
                     args->trans->t_mountp->m_sb.sb_blocksize, NULL);

      /*
       * Search through freemap for first-fit on new name length.
       * (may need to figure in size of entry struct too)
       */
      tablesize = (be16_to_cpu(hdr->count) + 1)
                              * sizeof(xfs_attr_leaf_entry_t)
                              + sizeof(xfs_attr_leaf_hdr_t);
      map = &hdr->freemap[XFS_ATTR_LEAF_MAPSIZE-1];
      for (sum = 0, i = XFS_ATTR_LEAF_MAPSIZE-1; i >= 0; map--, i--) {
            if (tablesize > be16_to_cpu(hdr->firstused)) {
                  sum += be16_to_cpu(map->size);
                  continue;
            }
            if (!map->size)
                  continue;   /* no space in this map */
            tmp = entsize;
            if (be16_to_cpu(map->base) < be16_to_cpu(hdr->firstused))
                  tmp += sizeof(xfs_attr_leaf_entry_t);
            if (be16_to_cpu(map->size) >= tmp) {
                  tmp = xfs_attr_leaf_add_work(bp, args, i);
                  return(tmp);
            }
            sum += be16_to_cpu(map->size);
      }

      /*
       * If there are no holes in the address space of the block,
       * and we don't have enough freespace, then compaction will do us
       * no good and we should just give up.
       */
      if (!hdr->holes && (sum < entsize))
            return(XFS_ERROR(ENOSPC));

      /*
       * Compact the entries to coalesce free space.
       * This may change the hdr->count via dropping INCOMPLETE entries.
       */
      xfs_attr_leaf_compact(args->trans, bp);

      /*
       * After compaction, the block is guaranteed to have only one
       * free region, in freemap[0].  If it is not big enough, give up.
       */
      if (be16_to_cpu(hdr->freemap[0].size)
                        < (entsize + sizeof(xfs_attr_leaf_entry_t)))
            return(XFS_ERROR(ENOSPC));

      return(xfs_attr_leaf_add_work(bp, args, 0));
}

/*
 * Add a name to a leaf attribute list structure.
 */
STATIC int
xfs_attr_leaf_add_work(xfs_dabuf_t *bp, xfs_da_args_t *args, int mapindex)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_hdr_t *hdr;
      xfs_attr_leaf_entry_t *entry;
      xfs_attr_leaf_name_local_t *name_loc;
      xfs_attr_leaf_name_remote_t *name_rmt;
      xfs_attr_leaf_map_t *map;
      xfs_mount_t *mp;
      int tmp, i;

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      hdr = &leaf->hdr;
      ASSERT((mapindex >= 0) && (mapindex < XFS_ATTR_LEAF_MAPSIZE));
      ASSERT((args->index >= 0) && (args->index <= be16_to_cpu(hdr->count)));

      /*
       * Force open some space in the entry array and fill it in.
       */
      entry = &leaf->entries[args->index];
      if (args->index < be16_to_cpu(hdr->count)) {
            tmp  = be16_to_cpu(hdr->count) - args->index;
            tmp *= sizeof(xfs_attr_leaf_entry_t);
            memmove((char *)(entry+1), (char *)entry, tmp);
            xfs_da_log_buf(args->trans, bp,
                XFS_DA_LOGRANGE(leaf, entry, tmp + sizeof(*entry)));
      }
      be16_add_cpu(&hdr->count, 1);

      /*
       * Allocate space for the new string (at the end of the run).
       */
      map = &hdr->freemap[mapindex];
      mp = args->trans->t_mountp;
      ASSERT(be16_to_cpu(map->base) < XFS_LBSIZE(mp));
      ASSERT((be16_to_cpu(map->base) & 0x3) == 0);
      ASSERT(be16_to_cpu(map->size) >=
            xfs_attr_leaf_newentsize(args->namelen, args->valuelen,
                               mp->m_sb.sb_blocksize, NULL));
      ASSERT(be16_to_cpu(map->size) < XFS_LBSIZE(mp));
      ASSERT((be16_to_cpu(map->size) & 0x3) == 0);
      be16_add_cpu(&map->size,
            -xfs_attr_leaf_newentsize(args->namelen, args->valuelen,
                                mp->m_sb.sb_blocksize, &tmp));
      entry->nameidx = cpu_to_be16(be16_to_cpu(map->base) +
                             be16_to_cpu(map->size));
      entry->hashval = cpu_to_be32(args->hashval);
      entry->flags = tmp ? XFS_ATTR_LOCAL : 0;
      entry->flags |= XFS_ATTR_NSP_ARGS_TO_ONDISK(args->flags);
      if (args->op_flags & XFS_DA_OP_RENAME) {
            entry->flags |= XFS_ATTR_INCOMPLETE;
            if ((args->blkno2 == args->blkno) &&
                (args->index2 <= args->index)) {
                  args->index2++;
            }
      }
      xfs_da_log_buf(args->trans, bp,
                    XFS_DA_LOGRANGE(leaf, entry, sizeof(*entry)));
      ASSERT((args->index == 0) ||
             (be32_to_cpu(entry->hashval) >= be32_to_cpu((entry-1)->hashval)));
      ASSERT((args->index == be16_to_cpu(hdr->count)-1) ||
             (be32_to_cpu(entry->hashval) <= be32_to_cpu((entry+1)->hashval)));

      /*
       * Copy the attribute name and value into the new space.
       *
       * For "remote" attribute values, simply note that we need to
       * allocate space for the "remote" value.  We can't actually
       * allocate the extents in this transaction, and we can't decide
       * which blocks they should be as we might allocate more blocks
       * as part of this transaction (a split operation for example).
       */
      if (entry->flags & XFS_ATTR_LOCAL) {
            name_loc = xfs_attr_leaf_name_local(leaf, args->index);
            name_loc->namelen = args->namelen;
            name_loc->valuelen = cpu_to_be16(args->valuelen);
            memcpy((char *)name_loc->nameval, args->name, args->namelen);
            memcpy((char *)&name_loc->nameval[args->namelen], args->value,
                           be16_to_cpu(name_loc->valuelen));
      } else {
            name_rmt = xfs_attr_leaf_name_remote(leaf, args->index);
            name_rmt->namelen = args->namelen;
            memcpy((char *)name_rmt->name, args->name, args->namelen);
            entry->flags |= XFS_ATTR_INCOMPLETE;
            /* just in case */
            name_rmt->valuelen = 0;
            name_rmt->valueblk = 0;
            args->rmtblkno = 1;
            args->rmtblkcnt = XFS_B_TO_FSB(mp, args->valuelen);
      }
      xfs_da_log_buf(args->trans, bp,
           XFS_DA_LOGRANGE(leaf, xfs_attr_leaf_name(leaf, args->index),
                           xfs_attr_leaf_entsize(leaf, args->index)));

      /*
       * Update the control info for this leaf node
       */
      if (be16_to_cpu(entry->nameidx) < be16_to_cpu(hdr->firstused)) {
            /* both on-disk, don't endian-flip twice */
            hdr->firstused = entry->nameidx;
      }
      ASSERT(be16_to_cpu(hdr->firstused) >=
             ((be16_to_cpu(hdr->count) * sizeof(*entry)) + sizeof(*hdr)));
      tmp = (be16_to_cpu(hdr->count)-1) * sizeof(xfs_attr_leaf_entry_t)
                              + sizeof(xfs_attr_leaf_hdr_t);
      map = &hdr->freemap[0];
      for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; map++, i++) {
            if (be16_to_cpu(map->base) == tmp) {
                  be16_add_cpu(&map->base, sizeof(xfs_attr_leaf_entry_t));
                  be16_add_cpu(&map->size,
                         -((int)sizeof(xfs_attr_leaf_entry_t)));
            }
      }
      be16_add_cpu(&hdr->usedbytes, xfs_attr_leaf_entsize(leaf, args->index));
      xfs_da_log_buf(args->trans, bp,
            XFS_DA_LOGRANGE(leaf, hdr, sizeof(*hdr)));
      return(0);
}

/*
 * Garbage collect a leaf attribute list block by copying it to a new buffer.
 */
STATIC void
xfs_attr_leaf_compact(xfs_trans_t *trans, xfs_dabuf_t *bp)
{
      xfs_attr_leafblock_t *leaf_s, *leaf_d;
      xfs_attr_leaf_hdr_t *hdr_s, *hdr_d;
      xfs_mount_t *mp;
      char *tmpbuffer;

      mp = trans->t_mountp;
      tmpbuffer = kmem_alloc(XFS_LBSIZE(mp), KM_SLEEP);
      ASSERT(tmpbuffer != NULL);
      memcpy(tmpbuffer, bp->data, XFS_LBSIZE(mp));
      memset(bp->data, 0, XFS_LBSIZE(mp));

      /*
       * Copy basic information
       */
      leaf_s = (xfs_attr_leafblock_t *)tmpbuffer;
      leaf_d = bp->data;
      hdr_s = &leaf_s->hdr;
      hdr_d = &leaf_d->hdr;
      hdr_d->info = hdr_s->info;    /* struct copy */
      hdr_d->firstused = cpu_to_be16(XFS_LBSIZE(mp));
      /* handle truncation gracefully */
      if (!hdr_d->firstused) {
            hdr_d->firstused = cpu_to_be16(
                        XFS_LBSIZE(mp) - XFS_ATTR_LEAF_NAME_ALIGN);
      }
      hdr_d->usedbytes = 0;
      hdr_d->count = 0;
      hdr_d->holes = 0;
      hdr_d->freemap[0].base = cpu_to_be16(sizeof(xfs_attr_leaf_hdr_t));
      hdr_d->freemap[0].size = cpu_to_be16(be16_to_cpu(hdr_d->firstused) -
                                   sizeof(xfs_attr_leaf_hdr_t));

      /*
       * Copy all entry's in the same (sorted) order,
       * but allocate name/value pairs packed and in sequence.
       */
      xfs_attr_leaf_moveents(leaf_s, 0, leaf_d, 0,
                        be16_to_cpu(hdr_s->count), mp);
      xfs_da_log_buf(trans, bp, 0, XFS_LBSIZE(mp) - 1);

      kmem_free(tmpbuffer);
}

/*
 * Redistribute the attribute list entries between two leaf nodes,
 * taking into account the size of the new entry.
 *
 * NOTE: if new block is empty, then it will get the upper half of the
 * old block.  At present, all (one) callers pass in an empty second block.
 *
 * This code adjusts the args->index/blkno and args->index2/blkno2 fields
 * to match what it is doing in splitting the attribute leaf block.  Those
 * values are used in "atomic rename" operations on attributes.  Note that
 * the "new" and "old" values can end up in different blocks.
 */
STATIC void
xfs_attr_leaf_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
                               xfs_da_state_blk_t *blk2)
{
      xfs_da_args_t *args;
      xfs_da_state_blk_t *tmp_blk;
      xfs_attr_leafblock_t *leaf1, *leaf2;
      xfs_attr_leaf_hdr_t *hdr1, *hdr2;
      int count, totallen, max, space, swap;

      /*
       * Set up environment.
       */
      ASSERT(blk1->magic == XFS_ATTR_LEAF_MAGIC);
      ASSERT(blk2->magic == XFS_ATTR_LEAF_MAGIC);
      leaf1 = blk1->bp->data;
      leaf2 = blk2->bp->data;
      ASSERT(be16_to_cpu(leaf1->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT(be16_to_cpu(leaf2->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      args = state->args;

      /*
       * Check ordering of blocks, reverse if it makes things simpler.
       *
       * NOTE: Given that all (current) callers pass in an empty
       * second block, this code should never set "swap".
       */
      swap = 0;
      if (xfs_attr_leaf_order(blk1->bp, blk2->bp)) {
            tmp_blk = blk1;
            blk1 = blk2;
            blk2 = tmp_blk;
            leaf1 = blk1->bp->data;
            leaf2 = blk2->bp->data;
            swap = 1;
      }
      hdr1 = &leaf1->hdr;
      hdr2 = &leaf2->hdr;

      /*
       * Examine entries until we reduce the absolute difference in
       * byte usage between the two blocks to a minimum.  Then get
       * the direction to copy and the number of elements to move.
       *
       * "inleaf" is true if the new entry should be inserted into blk1.
       * If "swap" is also true, then reverse the sense of "inleaf".
       */
      state->inleaf = xfs_attr_leaf_figure_balance(state, blk1, blk2,
                                              &count, &totallen);
      if (swap)
            state->inleaf = !state->inleaf;

      /*
       * Move any entries required from leaf to leaf:
       */
      if (count < be16_to_cpu(hdr1->count)) {
            /*
             * Figure the total bytes to be added to the destination leaf.
             */
            /* number entries being moved */
            count = be16_to_cpu(hdr1->count) - count;
            space  = be16_to_cpu(hdr1->usedbytes) - totallen;
            space += count * sizeof(xfs_attr_leaf_entry_t);

            /*
             * leaf2 is the destination, compact it if it looks tight.
             */
            max  = be16_to_cpu(hdr2->firstused)
                                    - sizeof(xfs_attr_leaf_hdr_t);
            max -= be16_to_cpu(hdr2->count) * sizeof(xfs_attr_leaf_entry_t);
            if (space > max) {
                  xfs_attr_leaf_compact(args->trans, blk2->bp);
            }

            /*
             * Move high entries from leaf1 to low end of leaf2.
             */
            xfs_attr_leaf_moveents(leaf1, be16_to_cpu(hdr1->count) - count,
                        leaf2, 0, count, state->mp);

            xfs_da_log_buf(args->trans, blk1->bp, 0, state->blocksize-1);
            xfs_da_log_buf(args->trans, blk2->bp, 0, state->blocksize-1);
      } else if (count > be16_to_cpu(hdr1->count)) {
            /*
             * I assert that since all callers pass in an empty
             * second buffer, this code should never execute.
             */

            /*
             * Figure the total bytes to be added to the destination leaf.
             */
            /* number entries being moved */
            count -= be16_to_cpu(hdr1->count);
            space  = totallen - be16_to_cpu(hdr1->usedbytes);
            space += count * sizeof(xfs_attr_leaf_entry_t);

            /*
             * leaf1 is the destination, compact it if it looks tight.
             */
            max  = be16_to_cpu(hdr1->firstused)
                                    - sizeof(xfs_attr_leaf_hdr_t);
            max -= be16_to_cpu(hdr1->count) * sizeof(xfs_attr_leaf_entry_t);
            if (space > max) {
                  xfs_attr_leaf_compact(args->trans, blk1->bp);
            }

            /*
             * Move low entries from leaf2 to high end of leaf1.
             */
            xfs_attr_leaf_moveents(leaf2, 0, leaf1,
                        be16_to_cpu(hdr1->count), count, state->mp);

            xfs_da_log_buf(args->trans, blk1->bp, 0, state->blocksize-1);
            xfs_da_log_buf(args->trans, blk2->bp, 0, state->blocksize-1);
      }

      /*
       * Copy out last hashval in each block for B-tree code.
       */
      blk1->hashval = be32_to_cpu(
            leaf1->entries[be16_to_cpu(leaf1->hdr.count)-1].hashval);
      blk2->hashval = be32_to_cpu(
            leaf2->entries[be16_to_cpu(leaf2->hdr.count)-1].hashval);

      /*
       * Adjust the expected index for insertion.
       * NOTE: this code depends on the (current) situation that the
       * second block was originally empty.
       *
       * If the insertion point moved to the 2nd block, we must adjust
       * the index.  We must also track the entry just following the
       * new entry for use in an "atomic rename" operation, that entry
       * is always the "old" entry and the "new" entry is what we are
       * inserting.  The index/blkno fields refer to the "old" entry,
       * while the index2/blkno2 fields refer to the "new" entry.
       */
      if (blk1->index > be16_to_cpu(leaf1->hdr.count)) {
            ASSERT(state->inleaf == 0);
            blk2->index = blk1->index - be16_to_cpu(leaf1->hdr.count);
            args->index = args->index2 = blk2->index;
            args->blkno = args->blkno2 = blk2->blkno;
      } else if (blk1->index == be16_to_cpu(leaf1->hdr.count)) {
            if (state->inleaf) {
                  args->index = blk1->index;
                  args->blkno = blk1->blkno;
                  args->index2 = 0;
                  args->blkno2 = blk2->blkno;
            } else {
                  blk2->index = blk1->index
                            - be16_to_cpu(leaf1->hdr.count);
                  args->index = args->index2 = blk2->index;
                  args->blkno = args->blkno2 = blk2->blkno;
            }
      } else {
            ASSERT(state->inleaf == 1);
            args->index = args->index2 = blk1->index;
            args->blkno = args->blkno2 = blk1->blkno;
      }
}

/*
 * Examine entries until we reduce the absolute difference in
 * byte usage between the two blocks to a minimum.
 * GROT: Is this really necessary?  With other than a 512 byte blocksize,
 * GROT: there will always be enough room in either block for a new entry.
 * GROT: Do a double-split for this case?
 */
STATIC int
xfs_attr_leaf_figure_balance(xfs_da_state_t *state,
                            xfs_da_state_blk_t *blk1,
                            xfs_da_state_blk_t *blk2,
                            int *countarg, int *usedbytesarg)
{
      xfs_attr_leafblock_t *leaf1, *leaf2;
      xfs_attr_leaf_hdr_t *hdr1, *hdr2;
      xfs_attr_leaf_entry_t *entry;
      int count, max, index, totallen, half;
      int lastdelta, foundit, tmp;

      /*
       * Set up environment.
       */
      leaf1 = blk1->bp->data;
      leaf2 = blk2->bp->data;
      hdr1 = &leaf1->hdr;
      hdr2 = &leaf2->hdr;
      foundit = 0;
      totallen = 0;

      /*
       * Examine entries until we reduce the absolute difference in
       * byte usage between the two blocks to a minimum.
       */
      max = be16_to_cpu(hdr1->count) + be16_to_cpu(hdr2->count);
      half  = (max+1) * sizeof(*entry);
      half += be16_to_cpu(hdr1->usedbytes) +
            be16_to_cpu(hdr2->usedbytes) +
            xfs_attr_leaf_newentsize(
                        state->args->namelen,
                        state->args->valuelen,
                        state->blocksize, NULL);
      half /= 2;
      lastdelta = state->blocksize;
      entry = &leaf1->entries[0];
      for (count = index = 0; count < max; entry++, index++, count++) {

#define XFS_ATTR_ABS(A) (((A) < 0) ? -(A) : (A))
            /*
             * The new entry is in the first block, account for it.
             */
            if (count == blk1->index) {
                  tmp = totallen + sizeof(*entry) +
                        xfs_attr_leaf_newentsize(
                                    state->args->namelen,
                                    state->args->valuelen,
                                    state->blocksize, NULL);
                  if (XFS_ATTR_ABS(half - tmp) > lastdelta)
                        break;
                  lastdelta = XFS_ATTR_ABS(half - tmp);
                  totallen = tmp;
                  foundit = 1;
            }

            /*
             * Wrap around into the second block if necessary.
             */
            if (count == be16_to_cpu(hdr1->count)) {
                  leaf1 = leaf2;
                  entry = &leaf1->entries[0];
                  index = 0;
            }

            /*
             * Figure out if next leaf entry would be too much.
             */
            tmp = totallen + sizeof(*entry) + xfs_attr_leaf_entsize(leaf1,
                                                      index);
            if (XFS_ATTR_ABS(half - tmp) > lastdelta)
                  break;
            lastdelta = XFS_ATTR_ABS(half - tmp);
            totallen = tmp;
#undef XFS_ATTR_ABS
      }

      /*
       * Calculate the number of usedbytes that will end up in lower block.
       * If new entry not in lower block, fix up the count.
       */
      totallen -= count * sizeof(*entry);
      if (foundit) {
            totallen -= sizeof(*entry) +
                        xfs_attr_leaf_newentsize(
                                    state->args->namelen,
                                    state->args->valuelen,
                                    state->blocksize, NULL);
      }

      *countarg = count;
      *usedbytesarg = totallen;
      return(foundit);
}

/*========================================================================
 * Routines used for shrinking the Btree.
 *========================================================================*/

/*
 * Check a leaf block and its neighbors to see if the block should be
 * collapsed into one or the other neighbor.  Always keep the block
 * with the smaller block number.
 * If the current block is over 50% full, don't try to join it, return 0.
 * If the block is empty, fill in the state structure and return 2.
 * If it can be collapsed, fill in the state structure and return 1.
 * If nothing can be done, return 0.
 *
 * GROT: allow for INCOMPLETE entries in calculation.
 */
int
xfs_attr_leaf_toosmall(xfs_da_state_t *state, int *action)
{
      xfs_attr_leafblock_t *leaf;
      xfs_da_state_blk_t *blk;
      xfs_da_blkinfo_t *info;
      int count, bytes, forward, error, retval, i;
      xfs_dablk_t blkno;
      xfs_dabuf_t *bp;

      /*
       * Check for the degenerate case of the block being over 50% full.
       * If so, it's not worth even looking to see if we might be able
       * to coalesce with a sibling.
       */
      blk = &state->path.blk[ state->path.active-1 ];
      info = blk->bp->data;
      ASSERT(be16_to_cpu(info->magic) == XFS_ATTR_LEAF_MAGIC);
      leaf = (xfs_attr_leafblock_t *)info;
      count = be16_to_cpu(leaf->hdr.count);
      bytes = sizeof(xfs_attr_leaf_hdr_t) +
            count * sizeof(xfs_attr_leaf_entry_t) +
            be16_to_cpu(leaf->hdr.usedbytes);
      if (bytes > (state->blocksize >> 1)) {
            *action = 0;      /* blk over 50%, don't try to join */
            return(0);
      }

      /*
       * Check for the degenerate case of the block being empty.
       * If the block is empty, we'll simply delete it, no need to
       * coalesce it with a sibling block.  We choose (arbitrarily)
       * to merge with the forward block unless it is NULL.
       */
      if (count == 0) {
            /*
             * Make altpath point to the block we want to keep and
             * path point to the block we want to drop (this one).
             */
            forward = (info->forw != 0);
            memcpy(&state->altpath, &state->path, sizeof(state->path));
            error = xfs_da_path_shift(state, &state->altpath, forward,
                                     0, &retval);
            if (error)
                  return(error);
            if (retval) {
                  *action = 0;
            } else {
                  *action = 2;
            }
            return(0);
      }

      /*
       * Examine each sibling block to see if we can coalesce with
       * at least 25% free space to spare.  We need to figure out
       * whether to merge with the forward or the backward block.
       * We prefer coalescing with the lower numbered sibling so as
       * to shrink an attribute list over time.
       */
      /* start with smaller blk num */
      forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back));
      for (i = 0; i < 2; forward = !forward, i++) {
            if (forward)
                  blkno = be32_to_cpu(info->forw);
            else
                  blkno = be32_to_cpu(info->back);
            if (blkno == 0)
                  continue;
            error = xfs_da_read_buf(state->args->trans, state->args->dp,
                              blkno, -1, &bp, XFS_ATTR_FORK);
            if (error)
                  return(error);
            ASSERT(bp != NULL);

            leaf = (xfs_attr_leafblock_t *)info;
            count  = be16_to_cpu(leaf->hdr.count);
            bytes  = state->blocksize - (state->blocksize>>2);
            bytes -= be16_to_cpu(leaf->hdr.usedbytes);
            leaf = bp->data;
            ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
            count += be16_to_cpu(leaf->hdr.count);
            bytes -= be16_to_cpu(leaf->hdr.usedbytes);
            bytes -= count * sizeof(xfs_attr_leaf_entry_t);
            bytes -= sizeof(xfs_attr_leaf_hdr_t);
            xfs_da_brelse(state->args->trans, bp);
            if (bytes >= 0)
                  break;      /* fits with at least 25% to spare */
      }
      if (i >= 2) {
            *action = 0;
            return(0);
      }

      /*
       * Make altpath point to the block we want to keep (the lower
       * numbered block) and path point to the block we want to drop.
       */
      memcpy(&state->altpath, &state->path, sizeof(state->path));
      if (blkno < blk->blkno) {
            error = xfs_da_path_shift(state, &state->altpath, forward,
                                     0, &retval);
      } else {
            error = xfs_da_path_shift(state, &state->path, forward,
                                     0, &retval);
      }
      if (error)
            return(error);
      if (retval) {
            *action = 0;
      } else {
            *action = 1;
      }
      return(0);
}

/*
 * Remove a name from the leaf attribute list structure.
 *
 * Return 1 if leaf is less than 37% full, 0 if >= 37% full.
 * If two leaves are 37% full, when combined they will leave 25% free.
 */
int
xfs_attr_leaf_remove(xfs_dabuf_t *bp, xfs_da_args_t *args)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_hdr_t *hdr;
      xfs_attr_leaf_map_t *map;
      xfs_attr_leaf_entry_t *entry;
      int before, after, smallest, entsize;
      int tablesize, tmp, i;
      xfs_mount_t *mp;

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      hdr = &leaf->hdr;
      mp = args->trans->t_mountp;
      ASSERT((be16_to_cpu(hdr->count) > 0)
            && (be16_to_cpu(hdr->count) < (XFS_LBSIZE(mp)/8)));
      ASSERT((args->index >= 0)
            && (args->index < be16_to_cpu(hdr->count)));
      ASSERT(be16_to_cpu(hdr->firstused) >=
             ((be16_to_cpu(hdr->count) * sizeof(*entry)) + sizeof(*hdr)));
      entry = &leaf->entries[args->index];
      ASSERT(be16_to_cpu(entry->nameidx) >= be16_to_cpu(hdr->firstused));
      ASSERT(be16_to_cpu(entry->nameidx) < XFS_LBSIZE(mp));

      /*
       * Scan through free region table:
       *    check for adjacency of free'd entry with an existing one,
       *    find smallest free region in case we need to replace it,
       *    adjust any map that borders the entry table,
       */
      tablesize = be16_to_cpu(hdr->count) * sizeof(xfs_attr_leaf_entry_t)
                              + sizeof(xfs_attr_leaf_hdr_t);
      map = &hdr->freemap[0];
      tmp = be16_to_cpu(map->size);
      before = after = -1;
      smallest = XFS_ATTR_LEAF_MAPSIZE - 1;
      entsize = xfs_attr_leaf_entsize(leaf, args->index);
      for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; map++, i++) {
            ASSERT(be16_to_cpu(map->base) < XFS_LBSIZE(mp));
            ASSERT(be16_to_cpu(map->size) < XFS_LBSIZE(mp));
            if (be16_to_cpu(map->base) == tablesize) {
                  be16_add_cpu(&map->base,
                         -((int)sizeof(xfs_attr_leaf_entry_t)));
                  be16_add_cpu(&map->size, sizeof(xfs_attr_leaf_entry_t));
            }

            if ((be16_to_cpu(map->base) + be16_to_cpu(map->size))
                        == be16_to_cpu(entry->nameidx)) {
                  before = i;
            } else if (be16_to_cpu(map->base)
                  == (be16_to_cpu(entry->nameidx) + entsize)) {
                  after = i;
            } else if (be16_to_cpu(map->size) < tmp) {
                  tmp = be16_to_cpu(map->size);
                  smallest = i;
            }
      }

      /*
       * Coalesce adjacent freemap regions,
       * or replace the smallest region.
       */
      if ((before >= 0) || (after >= 0)) {
            if ((before >= 0) && (after >= 0)) {
                  map = &hdr->freemap[before];
                  be16_add_cpu(&map->size, entsize);
                  be16_add_cpu(&map->size,
                         be16_to_cpu(hdr->freemap[after].size));
                  hdr->freemap[after].base = 0;
                  hdr->freemap[after].size = 0;
            } else if (before >= 0) {
                  map = &hdr->freemap[before];
                  be16_add_cpu(&map->size, entsize);
            } else {
                  map = &hdr->freemap[after];
                  /* both on-disk, don't endian flip twice */
                  map->base = entry->nameidx;
                  be16_add_cpu(&map->size, entsize);
            }
      } else {
            /*
             * Replace smallest region (if it is smaller than free'd entry)
             */
            map = &hdr->freemap[smallest];
            if (be16_to_cpu(map->size) < entsize) {
                  map->base = cpu_to_be16(be16_to_cpu(entry->nameidx));
                  map->size = cpu_to_be16(entsize);
            }
      }

      /*
       * Did we remove the first entry?
       */
      if (be16_to_cpu(entry->nameidx) == be16_to_cpu(hdr->firstused))
            smallest = 1;
      else
            smallest = 0;

      /*
       * Compress the remaining entries and zero out the removed stuff.
       */
      memset(xfs_attr_leaf_name(leaf, args->index), 0, entsize);
      be16_add_cpu(&hdr->usedbytes, -entsize);
      xfs_da_log_buf(args->trans, bp,
           XFS_DA_LOGRANGE(leaf, xfs_attr_leaf_name(leaf, args->index),
                           entsize));

      tmp = (be16_to_cpu(hdr->count) - args->index)
                              * sizeof(xfs_attr_leaf_entry_t);
      memmove((char *)entry, (char *)(entry+1), tmp);
      be16_add_cpu(&hdr->count, -1);
      xfs_da_log_buf(args->trans, bp,
          XFS_DA_LOGRANGE(leaf, entry, tmp + sizeof(*entry)));
      entry = &leaf->entries[be16_to_cpu(hdr->count)];
      memset((char *)entry, 0, sizeof(xfs_attr_leaf_entry_t));

      /*
       * If we removed the first entry, re-find the first used byte
       * in the name area.  Note that if the entry was the "firstused",
       * then we don't have a "hole" in our block resulting from
       * removing the name.
       */
      if (smallest) {
            tmp = XFS_LBSIZE(mp);
            entry = &leaf->entries[0];
            for (i = be16_to_cpu(hdr->count)-1; i >= 0; entry++, i--) {
                  ASSERT(be16_to_cpu(entry->nameidx) >=
                         be16_to_cpu(hdr->firstused));
                  ASSERT(be16_to_cpu(entry->nameidx) < XFS_LBSIZE(mp));

                  if (be16_to_cpu(entry->nameidx) < tmp)
                        tmp = be16_to_cpu(entry->nameidx);
            }
            hdr->firstused = cpu_to_be16(tmp);
            if (!hdr->firstused) {
                  hdr->firstused = cpu_to_be16(
                              tmp - XFS_ATTR_LEAF_NAME_ALIGN);
            }
      } else {
            hdr->holes = 1;         /* mark as needing compaction */
      }
      xfs_da_log_buf(args->trans, bp,
                    XFS_DA_LOGRANGE(leaf, hdr, sizeof(*hdr)));

      /*
       * Check if leaf is less than 50% full, caller may want to
       * "join" the leaf with a sibling if so.
       */
      tmp  = sizeof(xfs_attr_leaf_hdr_t);
      tmp += be16_to_cpu(leaf->hdr.count) * sizeof(xfs_attr_leaf_entry_t);
      tmp += be16_to_cpu(leaf->hdr.usedbytes);
      return(tmp < mp->m_attr_magicpct); /* leaf is < 37% full */
}

/*
 * Move all the attribute list entries from drop_leaf into save_leaf.
 */
void
xfs_attr_leaf_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
                               xfs_da_state_blk_t *save_blk)
{
      xfs_attr_leafblock_t *drop_leaf, *save_leaf, *tmp_leaf;
      xfs_attr_leaf_hdr_t *drop_hdr, *save_hdr, *tmp_hdr;
      xfs_mount_t *mp;
      char *tmpbuffer;

      /*
       * Set up environment.
       */
      mp = state->mp;
      ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC);
      ASSERT(save_blk->magic == XFS_ATTR_LEAF_MAGIC);
      drop_leaf = drop_blk->bp->data;
      save_leaf = save_blk->bp->data;
      ASSERT(be16_to_cpu(drop_leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT(be16_to_cpu(save_leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      drop_hdr = &drop_leaf->hdr;
      save_hdr = &save_leaf->hdr;

      /*
       * Save last hashval from dying block for later Btree fixup.
       */
      drop_blk->hashval = be32_to_cpu(
            drop_leaf->entries[be16_to_cpu(drop_leaf->hdr.count)-1].hashval);

      /*
       * Check if we need a temp buffer, or can we do it in place.
       * Note that we don't check "leaf" for holes because we will
       * always be dropping it, toosmall() decided that for us already.
       */
      if (save_hdr->holes == 0) {
            /*
             * dest leaf has no holes, so we add there.  May need
             * to make some room in the entry array.
             */
            if (xfs_attr_leaf_order(save_blk->bp, drop_blk->bp)) {
                  xfs_attr_leaf_moveents(drop_leaf, 0, save_leaf, 0,
                       be16_to_cpu(drop_hdr->count), mp);
            } else {
                  xfs_attr_leaf_moveents(drop_leaf, 0, save_leaf,
                          be16_to_cpu(save_hdr->count),
                          be16_to_cpu(drop_hdr->count), mp);
            }
      } else {
            /*
             * Destination has holes, so we make a temporary copy
             * of the leaf and add them both to that.
             */
            tmpbuffer = kmem_alloc(state->blocksize, KM_SLEEP);
            ASSERT(tmpbuffer != NULL);
            memset(tmpbuffer, 0, state->blocksize);
            tmp_leaf = (xfs_attr_leafblock_t *)tmpbuffer;
            tmp_hdr = &tmp_leaf->hdr;
            tmp_hdr->info = save_hdr->info;     /* struct copy */
            tmp_hdr->count = 0;
            tmp_hdr->firstused = cpu_to_be16(state->blocksize);
            if (!tmp_hdr->firstused) {
                  tmp_hdr->firstused = cpu_to_be16(
                        state->blocksize - XFS_ATTR_LEAF_NAME_ALIGN);
            }
            tmp_hdr->usedbytes = 0;
            if (xfs_attr_leaf_order(save_blk->bp, drop_blk->bp)) {
                  xfs_attr_leaf_moveents(drop_leaf, 0, tmp_leaf, 0,
                        be16_to_cpu(drop_hdr->count), mp);
                  xfs_attr_leaf_moveents(save_leaf, 0, tmp_leaf,
                          be16_to_cpu(tmp_leaf->hdr.count),
                          be16_to_cpu(save_hdr->count), mp);
            } else {
                  xfs_attr_leaf_moveents(save_leaf, 0, tmp_leaf, 0,
                        be16_to_cpu(save_hdr->count), mp);
                  xfs_attr_leaf_moveents(drop_leaf, 0, tmp_leaf,
                        be16_to_cpu(tmp_leaf->hdr.count),
                        be16_to_cpu(drop_hdr->count), mp);
            }
            memcpy((char *)save_leaf, (char *)tmp_leaf, state->blocksize);
            kmem_free(tmpbuffer);
      }

      xfs_da_log_buf(state->args->trans, save_blk->bp, 0,
                                 state->blocksize - 1);

      /*
       * Copy out last hashval in each block for B-tree code.
       */
      save_blk->hashval = be32_to_cpu(
            save_leaf->entries[be16_to_cpu(save_leaf->hdr.count)-1].hashval);
}

/*========================================================================
 * Routines used for finding things in the Btree.
 *========================================================================*/

/*
 * Look up a name in a leaf attribute list structure.
 * This is the internal routine, it uses the caller's buffer.
 *
 * Note that duplicate keys are allowed, but only check within the
 * current leaf node.  The Btree code must check in adjacent leaf nodes.
 *
 * Return in args->index the index into the entry[] array of either
 * the found entry, or where the entry should have been (insert before
 * that entry).
 *
 * Don't change the args->value unless we find the attribute.
 */
int
xfs_attr_leaf_lookup_int(xfs_dabuf_t *bp, xfs_da_args_t *args)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_entry_t *entry;
      xfs_attr_leaf_name_local_t *name_loc;
      xfs_attr_leaf_name_remote_t *name_rmt;
      int probe, span;
      xfs_dahash_t hashval;

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT(be16_to_cpu(leaf->hdr.count)
                              < (XFS_LBSIZE(args->dp->i_mount)/8));

      /*
       * Binary search.  (note: small blocks will skip this loop)
       */
      hashval = args->hashval;
      probe = span = be16_to_cpu(leaf->hdr.count) / 2;
      for (entry = &leaf->entries[probe]; span > 4;
               entry = &leaf->entries[probe]) {
            span /= 2;
            if (be32_to_cpu(entry->hashval) < hashval)
                  probe += span;
            else if (be32_to_cpu(entry->hashval) > hashval)
                  probe -= span;
            else
                  break;
      }
      ASSERT((probe >= 0) &&
             (!leaf->hdr.count
             || (probe < be16_to_cpu(leaf->hdr.count))));
      ASSERT((span <= 4) || (be32_to_cpu(entry->hashval) == hashval));

      /*
       * Since we may have duplicate hashval's, find the first matching
       * hashval in the leaf.
       */
      while ((probe > 0) && (be32_to_cpu(entry->hashval) >= hashval)) {
            entry--;
            probe--;
      }
      while ((probe < be16_to_cpu(leaf->hdr.count)) &&
             (be32_to_cpu(entry->hashval) < hashval)) {
            entry++;
            probe++;
      }
      if ((probe == be16_to_cpu(leaf->hdr.count)) ||
          (be32_to_cpu(entry->hashval) != hashval)) {
            args->index = probe;
            return(XFS_ERROR(ENOATTR));
      }

      /*
       * Duplicate keys may be present, so search all of them for a match.
       */
      for (  ; (probe < be16_to_cpu(leaf->hdr.count)) &&
                  (be32_to_cpu(entry->hashval) == hashval);
                  entry++, probe++) {
/*
 * GROT: Add code to remove incomplete entries.
 */
            /*
             * If we are looking for INCOMPLETE entries, show only those.
             * If we are looking for complete entries, show only those.
             */
            if ((args->flags & XFS_ATTR_INCOMPLETE) !=
                (entry->flags & XFS_ATTR_INCOMPLETE)) {
                  continue;
            }
            if (entry->flags & XFS_ATTR_LOCAL) {
                  name_loc = xfs_attr_leaf_name_local(leaf, probe);
                  if (name_loc->namelen != args->namelen)
                        continue;
                  if (memcmp(args->name, (char *)name_loc->nameval, args->namelen) != 0)
                        continue;
                  if (!xfs_attr_namesp_match(args->flags, entry->flags))
                        continue;
                  args->index = probe;
                  return(XFS_ERROR(EEXIST));
            } else {
                  name_rmt = xfs_attr_leaf_name_remote(leaf, probe);
                  if (name_rmt->namelen != args->namelen)
                        continue;
                  if (memcmp(args->name, (char *)name_rmt->name,
                                   args->namelen) != 0)
                        continue;
                  if (!xfs_attr_namesp_match(args->flags, entry->flags))
                        continue;
                  args->index = probe;
                  args->rmtblkno = be32_to_cpu(name_rmt->valueblk);
                  args->rmtblkcnt = XFS_B_TO_FSB(args->dp->i_mount,
                                       be32_to_cpu(name_rmt->valuelen));
                  return(XFS_ERROR(EEXIST));
            }
      }
      args->index = probe;
      return(XFS_ERROR(ENOATTR));
}

/*
 * Get the value associated with an attribute name from a leaf attribute
 * list structure.
 */
int
xfs_attr_leaf_getvalue(xfs_dabuf_t *bp, xfs_da_args_t *args)
{
      int valuelen;
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_entry_t *entry;
      xfs_attr_leaf_name_local_t *name_loc;
      xfs_attr_leaf_name_remote_t *name_rmt;

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT(be16_to_cpu(leaf->hdr.count)
                              < (XFS_LBSIZE(args->dp->i_mount)/8));
      ASSERT(args->index < be16_to_cpu(leaf->hdr.count));

      entry = &leaf->entries[args->index];
      if (entry->flags & XFS_ATTR_LOCAL) {
            name_loc = xfs_attr_leaf_name_local(leaf, args->index);
            ASSERT(name_loc->namelen == args->namelen);
            ASSERT(memcmp(args->name, name_loc->nameval, args->namelen) == 0);
            valuelen = be16_to_cpu(name_loc->valuelen);
            if (args->flags & ATTR_KERNOVAL) {
                  args->valuelen = valuelen;
                  return(0);
            }
            if (args->valuelen < valuelen) {
                  args->valuelen = valuelen;
                  return(XFS_ERROR(ERANGE));
            }
            args->valuelen = valuelen;
            memcpy(args->value, &name_loc->nameval[args->namelen], valuelen);
      } else {
            name_rmt = xfs_attr_leaf_name_remote(leaf, args->index);
            ASSERT(name_rmt->namelen == args->namelen);
            ASSERT(memcmp(args->name, name_rmt->name, args->namelen) == 0);
            valuelen = be32_to_cpu(name_rmt->valuelen);
            args->rmtblkno = be32_to_cpu(name_rmt->valueblk);
            args->rmtblkcnt = XFS_B_TO_FSB(args->dp->i_mount, valuelen);
            if (args->flags & ATTR_KERNOVAL) {
                  args->valuelen = valuelen;
                  return(0);
            }
            if (args->valuelen < valuelen) {
                  args->valuelen = valuelen;
                  return(XFS_ERROR(ERANGE));
            }
            args->valuelen = valuelen;
      }
      return(0);
}

/*========================================================================
 * Utility routines.
 *========================================================================*/

/*
 * Move the indicated entries from one leaf to another.
 * NOTE: this routine modifies both source and destination leaves.
 */
/*ARGSUSED*/
STATIC void
xfs_attr_leaf_moveents(xfs_attr_leafblock_t *leaf_s, int start_s,
                  xfs_attr_leafblock_t *leaf_d, int start_d,
                  int count, xfs_mount_t *mp)
{
      xfs_attr_leaf_hdr_t *hdr_s, *hdr_d;
      xfs_attr_leaf_entry_t *entry_s, *entry_d;
      int desti, tmp, i;

      /*
       * Check for nothing to do.
       */
      if (count == 0)
            return;

      /*
       * Set up environment.
       */
      ASSERT(be16_to_cpu(leaf_s->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT(be16_to_cpu(leaf_d->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      hdr_s = &leaf_s->hdr;
      hdr_d = &leaf_d->hdr;
      ASSERT((be16_to_cpu(hdr_s->count) > 0) &&
             (be16_to_cpu(hdr_s->count) < (XFS_LBSIZE(mp)/8)));
      ASSERT(be16_to_cpu(hdr_s->firstused) >=
            ((be16_to_cpu(hdr_s->count)
                              * sizeof(*entry_s))+sizeof(*hdr_s)));
      ASSERT(be16_to_cpu(hdr_d->count) < (XFS_LBSIZE(mp)/8));
      ASSERT(be16_to_cpu(hdr_d->firstused) >=
            ((be16_to_cpu(hdr_d->count)
                              * sizeof(*entry_d))+sizeof(*hdr_d)));

      ASSERT(start_s < be16_to_cpu(hdr_s->count));
      ASSERT(start_d <= be16_to_cpu(hdr_d->count));
      ASSERT(count <= be16_to_cpu(hdr_s->count));

      /*
       * Move the entries in the destination leaf up to make a hole?
       */
      if (start_d < be16_to_cpu(hdr_d->count)) {
            tmp  = be16_to_cpu(hdr_d->count) - start_d;
            tmp *= sizeof(xfs_attr_leaf_entry_t);
            entry_s = &leaf_d->entries[start_d];
            entry_d = &leaf_d->entries[start_d + count];
            memmove((char *)entry_d, (char *)entry_s, tmp);
      }

      /*
       * Copy all entry's in the same (sorted) order,
       * but allocate attribute info packed and in sequence.
       */
      entry_s = &leaf_s->entries[start_s];
      entry_d = &leaf_d->entries[start_d];
      desti = start_d;
      for (i = 0; i < count; entry_s++, entry_d++, desti++, i++) {
            ASSERT(be16_to_cpu(entry_s->nameidx)
                        >= be16_to_cpu(hdr_s->firstused));
            tmp = xfs_attr_leaf_entsize(leaf_s, start_s + i);
#ifdef GROT
            /*
             * Code to drop INCOMPLETE entries.  Difficult to use as we
             * may also need to change the insertion index.  Code turned
             * off for 6.2, should be revisited later.
             */
            if (entry_s->flags & XFS_ATTR_INCOMPLETE) { /* skip partials? */
                  memset(xfs_attr_leaf_name(leaf_s, start_s + i), 0, tmp);
                  be16_add_cpu(&hdr_s->usedbytes, -tmp);
                  be16_add_cpu(&hdr_s->count, -1);
                  entry_d--;  /* to compensate for ++ in loop hdr */
                  desti--;
                  if ((start_s + i) < offset)
                        result++;   /* insertion index adjustment */
            } else {
#endif /* GROT */
                  be16_add_cpu(&hdr_d->firstused, -tmp);
                  /* both on-disk, don't endian flip twice */
                  entry_d->hashval = entry_s->hashval;
                  /* both on-disk, don't endian flip twice */
                  entry_d->nameidx = hdr_d->firstused;
                  entry_d->flags = entry_s->flags;
                  ASSERT(be16_to_cpu(entry_d->nameidx) + tmp
                                          <= XFS_LBSIZE(mp));
                  memmove(xfs_attr_leaf_name(leaf_d, desti),
                        xfs_attr_leaf_name(leaf_s, start_s + i), tmp);
                  ASSERT(be16_to_cpu(entry_s->nameidx) + tmp
                                          <= XFS_LBSIZE(mp));
                  memset(xfs_attr_leaf_name(leaf_s, start_s + i), 0, tmp);
                  be16_add_cpu(&hdr_s->usedbytes, -tmp);
                  be16_add_cpu(&hdr_d->usedbytes, tmp);
                  be16_add_cpu(&hdr_s->count, -1);
                  be16_add_cpu(&hdr_d->count, 1);
                  tmp = be16_to_cpu(hdr_d->count)
                                    * sizeof(xfs_attr_leaf_entry_t)
                                    + sizeof(xfs_attr_leaf_hdr_t);
                  ASSERT(be16_to_cpu(hdr_d->firstused) >= tmp);
#ifdef GROT
            }
#endif /* GROT */
      }

      /*
       * Zero out the entries we just copied.
       */
      if (start_s == be16_to_cpu(hdr_s->count)) {
            tmp = count * sizeof(xfs_attr_leaf_entry_t);
            entry_s = &leaf_s->entries[start_s];
            ASSERT(((char *)entry_s + tmp) <=
                   ((char *)leaf_s + XFS_LBSIZE(mp)));
            memset((char *)entry_s, 0, tmp);
      } else {
            /*
             * Move the remaining entries down to fill the hole,
             * then zero the entries at the top.
             */
            tmp  = be16_to_cpu(hdr_s->count) - count;
            tmp *= sizeof(xfs_attr_leaf_entry_t);
            entry_s = &leaf_s->entries[start_s + count];
            entry_d = &leaf_s->entries[start_s];
            memmove((char *)entry_d, (char *)entry_s, tmp);

            tmp = count * sizeof(xfs_attr_leaf_entry_t);
            entry_s = &leaf_s->entries[be16_to_cpu(hdr_s->count)];
            ASSERT(((char *)entry_s + tmp) <=
                   ((char *)leaf_s + XFS_LBSIZE(mp)));
            memset((char *)entry_s, 0, tmp);
      }

      /*
       * Fill in the freemap information
       */
      hdr_d->freemap[0].base = cpu_to_be16(sizeof(xfs_attr_leaf_hdr_t));
      be16_add_cpu(&hdr_d->freemap[0].base, be16_to_cpu(hdr_d->count) *
                  sizeof(xfs_attr_leaf_entry_t));
      hdr_d->freemap[0].size = cpu_to_be16(be16_to_cpu(hdr_d->firstused)
                        - be16_to_cpu(hdr_d->freemap[0].base));
      hdr_d->freemap[1].base = 0;
      hdr_d->freemap[2].base = 0;
      hdr_d->freemap[1].size = 0;
      hdr_d->freemap[2].size = 0;
      hdr_s->holes = 1; /* leaf may not be compact */
}

/*
 * Compare two leaf blocks "order".
 * Return 0 unless leaf2 should go before leaf1.
 */
int
xfs_attr_leaf_order(xfs_dabuf_t *leaf1_bp, xfs_dabuf_t *leaf2_bp)
{
      xfs_attr_leafblock_t *leaf1, *leaf2;

      leaf1 = leaf1_bp->data;
      leaf2 = leaf2_bp->data;
      ASSERT((be16_to_cpu(leaf1->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC) &&
             (be16_to_cpu(leaf2->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC));
      if ((be16_to_cpu(leaf1->hdr.count) > 0) &&
          (be16_to_cpu(leaf2->hdr.count) > 0) &&
          ((be32_to_cpu(leaf2->entries[0].hashval) <
            be32_to_cpu(leaf1->entries[0].hashval)) ||
           (be32_to_cpu(leaf2->entries[
                  be16_to_cpu(leaf2->hdr.count)-1].hashval) <
            be32_to_cpu(leaf1->entries[
                  be16_to_cpu(leaf1->hdr.count)-1].hashval)))) {
            return(1);
      }
      return(0);
}

/*
 * Pick up the last hashvalue from a leaf block.
 */
xfs_dahash_t
xfs_attr_leaf_lasthash(xfs_dabuf_t *bp, int *count)
{
      xfs_attr_leafblock_t *leaf;

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      if (count)
            *count = be16_to_cpu(leaf->hdr.count);
      if (!leaf->hdr.count)
            return(0);
      return be32_to_cpu(leaf->entries[be16_to_cpu(leaf->hdr.count)-1].hashval);
}

/*
 * Calculate the number of bytes used to store the indicated attribute
 * (whether local or remote only calculate bytes in this block).
 */
STATIC int
xfs_attr_leaf_entsize(xfs_attr_leafblock_t *leaf, int index)
{
      xfs_attr_leaf_name_local_t *name_loc;
      xfs_attr_leaf_name_remote_t *name_rmt;
      int size;

      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      if (leaf->entries[index].flags & XFS_ATTR_LOCAL) {
            name_loc = xfs_attr_leaf_name_local(leaf, index);
            size = xfs_attr_leaf_entsize_local(name_loc->namelen,
                                       be16_to_cpu(name_loc->valuelen));
      } else {
            name_rmt = xfs_attr_leaf_name_remote(leaf, index);
            size = xfs_attr_leaf_entsize_remote(name_rmt->namelen);
      }
      return(size);
}

/*
 * Calculate the number of bytes that would be required to store the new
 * attribute (whether local or remote only calculate bytes in this block).
 * This routine decides as a side effect whether the attribute will be
 * a "local" or a "remote" attribute.
 */
int
xfs_attr_leaf_newentsize(int namelen, int valuelen, int blocksize, int *local)
{
      int size;

      size = xfs_attr_leaf_entsize_local(namelen, valuelen);
      if (size < xfs_attr_leaf_entsize_local_max(blocksize)) {
            if (local) {
                  *local = 1;
            }
      } else {
            size = xfs_attr_leaf_entsize_remote(namelen);
            if (local) {
                  *local = 0;
            }
      }
      return(size);
}

/*
 * Copy out attribute list entries for attr_list(), for leaf attribute lists.
 */
int
xfs_attr_leaf_list_int(xfs_dabuf_t *bp, xfs_attr_list_context_t *context)
{
      attrlist_cursor_kern_t *cursor;
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_entry_t *entry;
      int retval, i;

      ASSERT(bp != NULL);
      leaf = bp->data;
      cursor = context->cursor;
      cursor->initted = 1;

      xfs_attr_trace_l_cl("blk start", context, leaf);

      /*
       * Re-find our place in the leaf block if this is a new syscall.
       */
      if (context->resynch) {
            entry = &leaf->entries[0];
            for (i = 0; i < be16_to_cpu(leaf->hdr.count); entry++, i++) {
                  if (be32_to_cpu(entry->hashval) == cursor->hashval) {
                        if (cursor->offset == context->dupcnt) {
                              context->dupcnt = 0;
                              break;
                        }
                        context->dupcnt++;
                  } else if (be32_to_cpu(entry->hashval) >
                              cursor->hashval) {
                        context->dupcnt = 0;
                        break;
                  }
            }
            if (i == be16_to_cpu(leaf->hdr.count)) {
                  xfs_attr_trace_l_c("not found", context);
                  return(0);
            }
      } else {
            entry = &leaf->entries[0];
            i = 0;
      }
      context->resynch = 0;

      /*
       * We have found our place, start copying out the new attributes.
       */
      retval = 0;
      for (  ; (i < be16_to_cpu(leaf->hdr.count)); entry++, i++) {
            if (be32_to_cpu(entry->hashval) != cursor->hashval) {
                  cursor->hashval = be32_to_cpu(entry->hashval);
                  cursor->offset = 0;
            }

            if (entry->flags & XFS_ATTR_INCOMPLETE)
                  continue;         /* skip incomplete entries */

            if (entry->flags & XFS_ATTR_LOCAL) {
                  xfs_attr_leaf_name_local_t *name_loc =
                        xfs_attr_leaf_name_local(leaf, i);

                  retval = context->put_listent(context,
                                    entry->flags,
                                    (char *)name_loc->nameval,
                                    (int)name_loc->namelen,
                                    be16_to_cpu(name_loc->valuelen),
                                    (char *)&name_loc->nameval[name_loc->namelen]);
                  if (retval)
                        return retval;
            } else {
                  xfs_attr_leaf_name_remote_t *name_rmt =
                        xfs_attr_leaf_name_remote(leaf, i);

                  int valuelen = be32_to_cpu(name_rmt->valuelen);

                  if (context->put_value) {
                        xfs_da_args_t args;

                        memset((char *)&args, 0, sizeof(args));
                        args.dp = context->dp;
                        args.whichfork = XFS_ATTR_FORK;
                        args.valuelen = valuelen;
                        args.value = kmem_alloc(valuelen, KM_SLEEP);
                        args.rmtblkno = be32_to_cpu(name_rmt->valueblk);
                        args.rmtblkcnt = XFS_B_TO_FSB(args.dp->i_mount, valuelen);
                        retval = xfs_attr_rmtval_get(&args);
                        if (retval)
                              return retval;
                        retval = context->put_listent(context,
                                    entry->flags,
                                    (char *)name_rmt->name,
                                    (int)name_rmt->namelen,
                                    valuelen,
                                    (char*)args.value);
                        kmem_free(args.value);
                  } else {
                        retval = context->put_listent(context,
                                    entry->flags,
                                    (char *)name_rmt->name,
                                    (int)name_rmt->namelen,
                                    valuelen,
                                    NULL);
                  }
                  if (retval)
                        return retval;
            }
            if (context->seen_enough)
                  break;
            cursor->offset++;
      }
      xfs_attr_trace_l_cl("blk end", context, leaf);
      return(retval);
}


/*========================================================================
 * Manage the INCOMPLETE flag in a leaf entry
 *========================================================================*/

/*
 * Clear the INCOMPLETE flag on an entry in a leaf block.
 */
int
xfs_attr_leaf_clearflag(xfs_da_args_t *args)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_entry_t *entry;
      xfs_attr_leaf_name_remote_t *name_rmt;
      xfs_dabuf_t *bp;
      int error;
#ifdef DEBUG
      xfs_attr_leaf_name_local_t *name_loc;
      int namelen;
      char *name;
#endif /* DEBUG */

      /*
       * Set up the operation.
       */
      error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1, &bp,
                                   XFS_ATTR_FORK);
      if (error) {
            return(error);
      }
      ASSERT(bp != NULL);

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT(args->index < be16_to_cpu(leaf->hdr.count));
      ASSERT(args->index >= 0);
      entry = &leaf->entries[ args->index ];
      ASSERT(entry->flags & XFS_ATTR_INCOMPLETE);

#ifdef DEBUG
      if (entry->flags & XFS_ATTR_LOCAL) {
            name_loc = xfs_attr_leaf_name_local(leaf, args->index);
            namelen = name_loc->namelen;
            name = (char *)name_loc->nameval;
      } else {
            name_rmt = xfs_attr_leaf_name_remote(leaf, args->index);
            namelen = name_rmt->namelen;
            name = (char *)name_rmt->name;
      }
      ASSERT(be32_to_cpu(entry->hashval) == args->hashval);
      ASSERT(namelen == args->namelen);
      ASSERT(memcmp(name, args->name, namelen) == 0);
#endif /* DEBUG */

      entry->flags &= ~XFS_ATTR_INCOMPLETE;
      xfs_da_log_buf(args->trans, bp,
                   XFS_DA_LOGRANGE(leaf, entry, sizeof(*entry)));

      if (args->rmtblkno) {
            ASSERT((entry->flags & XFS_ATTR_LOCAL) == 0);
            name_rmt = xfs_attr_leaf_name_remote(leaf, args->index);
            name_rmt->valueblk = cpu_to_be32(args->rmtblkno);
            name_rmt->valuelen = cpu_to_be32(args->valuelen);
            xfs_da_log_buf(args->trans, bp,
                   XFS_DA_LOGRANGE(leaf, name_rmt, sizeof(*name_rmt)));
      }
      xfs_da_buf_done(bp);

      /*
       * Commit the flag value change and start the next trans in series.
       */
      return xfs_trans_roll(&args->trans, args->dp);
}

/*
 * Set the INCOMPLETE flag on an entry in a leaf block.
 */
int
xfs_attr_leaf_setflag(xfs_da_args_t *args)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_entry_t *entry;
      xfs_attr_leaf_name_remote_t *name_rmt;
      xfs_dabuf_t *bp;
      int error;

      /*
       * Set up the operation.
       */
      error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1, &bp,
                                   XFS_ATTR_FORK);
      if (error) {
            return(error);
      }
      ASSERT(bp != NULL);

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT(args->index < be16_to_cpu(leaf->hdr.count));
      ASSERT(args->index >= 0);
      entry = &leaf->entries[ args->index ];

      ASSERT((entry->flags & XFS_ATTR_INCOMPLETE) == 0);
      entry->flags |= XFS_ATTR_INCOMPLETE;
      xfs_da_log_buf(args->trans, bp,
                  XFS_DA_LOGRANGE(leaf, entry, sizeof(*entry)));
      if ((entry->flags & XFS_ATTR_LOCAL) == 0) {
            name_rmt = xfs_attr_leaf_name_remote(leaf, args->index);
            name_rmt->valueblk = 0;
            name_rmt->valuelen = 0;
            xfs_da_log_buf(args->trans, bp,
                   XFS_DA_LOGRANGE(leaf, name_rmt, sizeof(*name_rmt)));
      }
      xfs_da_buf_done(bp);

      /*
       * Commit the flag value change and start the next trans in series.
       */
      return xfs_trans_roll(&args->trans, args->dp);
}

/*
 * In a single transaction, clear the INCOMPLETE flag on the leaf entry
 * given by args->blkno/index and set the INCOMPLETE flag on the leaf
 * entry given by args->blkno2/index2.
 *
 * Note that they could be in different blocks, or in the same block.
 */
int
xfs_attr_leaf_flipflags(xfs_da_args_t *args)
{
      xfs_attr_leafblock_t *leaf1, *leaf2;
      xfs_attr_leaf_entry_t *entry1, *entry2;
      xfs_attr_leaf_name_remote_t *name_rmt;
      xfs_dabuf_t *bp1, *bp2;
      int error;
#ifdef DEBUG
      xfs_attr_leaf_name_local_t *name_loc;
      int namelen1, namelen2;
      char *name1, *name2;
#endif /* DEBUG */

      /*
       * Read the block containing the "old" attr
       */
      error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1, &bp1,
                                   XFS_ATTR_FORK);
      if (error) {
            return(error);
      }
      ASSERT(bp1 != NULL);

      /*
       * Read the block containing the "new" attr, if it is different
       */
      if (args->blkno2 != args->blkno) {
            error = xfs_da_read_buf(args->trans, args->dp, args->blkno2,
                              -1, &bp2, XFS_ATTR_FORK);
            if (error) {
                  return(error);
            }
            ASSERT(bp2 != NULL);
      } else {
            bp2 = bp1;
      }

      leaf1 = bp1->data;
      ASSERT(be16_to_cpu(leaf1->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT(args->index < be16_to_cpu(leaf1->hdr.count));
      ASSERT(args->index >= 0);
      entry1 = &leaf1->entries[ args->index ];

      leaf2 = bp2->data;
      ASSERT(be16_to_cpu(leaf2->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);
      ASSERT(args->index2 < be16_to_cpu(leaf2->hdr.count));
      ASSERT(args->index2 >= 0);
      entry2 = &leaf2->entries[ args->index2 ];

#ifdef DEBUG
      if (entry1->flags & XFS_ATTR_LOCAL) {
            name_loc = xfs_attr_leaf_name_local(leaf1, args->index);
            namelen1 = name_loc->namelen;
            name1 = (char *)name_loc->nameval;
      } else {
            name_rmt = xfs_attr_leaf_name_remote(leaf1, args->index);
            namelen1 = name_rmt->namelen;
            name1 = (char *)name_rmt->name;
      }
      if (entry2->flags & XFS_ATTR_LOCAL) {
            name_loc = xfs_attr_leaf_name_local(leaf2, args->index2);
            namelen2 = name_loc->namelen;
            name2 = (char *)name_loc->nameval;
      } else {
            name_rmt = xfs_attr_leaf_name_remote(leaf2, args->index2);
            namelen2 = name_rmt->namelen;
            name2 = (char *)name_rmt->name;
      }
      ASSERT(be32_to_cpu(entry1->hashval) == be32_to_cpu(entry2->hashval));
      ASSERT(namelen1 == namelen2);
      ASSERT(memcmp(name1, name2, namelen1) == 0);
#endif /* DEBUG */

      ASSERT(entry1->flags & XFS_ATTR_INCOMPLETE);
      ASSERT((entry2->flags & XFS_ATTR_INCOMPLETE) == 0);

      entry1->flags &= ~XFS_ATTR_INCOMPLETE;
      xfs_da_log_buf(args->trans, bp1,
                    XFS_DA_LOGRANGE(leaf1, entry1, sizeof(*entry1)));
      if (args->rmtblkno) {
            ASSERT((entry1->flags & XFS_ATTR_LOCAL) == 0);
            name_rmt = xfs_attr_leaf_name_remote(leaf1, args->index);
            name_rmt->valueblk = cpu_to_be32(args->rmtblkno);
            name_rmt->valuelen = cpu_to_be32(args->valuelen);
            xfs_da_log_buf(args->trans, bp1,
                   XFS_DA_LOGRANGE(leaf1, name_rmt, sizeof(*name_rmt)));
      }

      entry2->flags |= XFS_ATTR_INCOMPLETE;
      xfs_da_log_buf(args->trans, bp2,
                    XFS_DA_LOGRANGE(leaf2, entry2, sizeof(*entry2)));
      if ((entry2->flags & XFS_ATTR_LOCAL) == 0) {
            name_rmt = xfs_attr_leaf_name_remote(leaf2, args->index2);
            name_rmt->valueblk = 0;
            name_rmt->valuelen = 0;
            xfs_da_log_buf(args->trans, bp2,
                   XFS_DA_LOGRANGE(leaf2, name_rmt, sizeof(*name_rmt)));
      }
      xfs_da_buf_done(bp1);
      if (bp1 != bp2)
            xfs_da_buf_done(bp2);

      /*
       * Commit the flag value change and start the next trans in series.
       */
      error = xfs_trans_roll(&args->trans, args->dp);

      return(error);
}

/*========================================================================
 * Indiscriminately delete the entire attribute fork
 *========================================================================*/

/*
 * Recurse (gasp!) through the attribute nodes until we find leaves.
 * We're doing a depth-first traversal in order to invalidate everything.
 */
int
xfs_attr_root_inactive(xfs_trans_t **trans, xfs_inode_t *dp)
{
      xfs_da_blkinfo_t *info;
      xfs_daddr_t blkno;
      xfs_dabuf_t *bp;
      int error;

      /*
       * Read block 0 to see what we have to work with.
       * We only get here if we have extents, since we remove
       * the extents in reverse order the extent containing
       * block 0 must still be there.
       */
      error = xfs_da_read_buf(*trans, dp, 0, -1, &bp, XFS_ATTR_FORK);
      if (error)
            return(error);
      blkno = xfs_da_blkno(bp);

      /*
       * Invalidate the tree, even if the "tree" is only a single leaf block.
       * This is a depth-first traversal!
       */
      info = bp->data;
      if (be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC) {
            error = xfs_attr_node_inactive(trans, dp, bp, 1);
      } else if (be16_to_cpu(info->magic) == XFS_ATTR_LEAF_MAGIC) {
            error = xfs_attr_leaf_inactive(trans, dp, bp);
      } else {
            error = XFS_ERROR(EIO);
            xfs_da_brelse(*trans, bp);
      }
      if (error)
            return(error);

      /*
       * Invalidate the incore copy of the root block.
       */
      error = xfs_da_get_buf(*trans, dp, 0, blkno, &bp, XFS_ATTR_FORK);
      if (error)
            return(error);
      xfs_da_binval(*trans, bp);    /* remove from cache */
      /*
       * Commit the invalidate and start the next transaction.
       */
      error = xfs_trans_roll(trans, dp);

      return (error);
}

/*
 * Recurse (gasp!) through the attribute nodes until we find leaves.
 * We're doing a depth-first traversal in order to invalidate everything.
 */
STATIC int
xfs_attr_node_inactive(xfs_trans_t **trans, xfs_inode_t *dp, xfs_dabuf_t *bp,
                           int level)
{
      xfs_da_blkinfo_t *info;
      xfs_da_intnode_t *node;
      xfs_dablk_t child_fsb;
      xfs_daddr_t parent_blkno, child_blkno;
      int error, count, i;
      xfs_dabuf_t *child_bp;

      /*
       * Since this code is recursive (gasp!) we must protect ourselves.
       */
      if (level > XFS_DA_NODE_MAXDEPTH) {
            xfs_da_brelse(*trans, bp);    /* no locks for later trans */
            return(XFS_ERROR(EIO));
      }

      node = bp->data;
      ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
      parent_blkno = xfs_da_blkno(bp);    /* save for re-read later */
      count = be16_to_cpu(node->hdr.count);
      if (!count) {
            xfs_da_brelse(*trans, bp);
            return(0);
      }
      child_fsb = be32_to_cpu(node->btree[0].before);
      xfs_da_brelse(*trans, bp);    /* no locks for later trans */

      /*
       * If this is the node level just above the leaves, simply loop
       * over the leaves removing all of them.  If this is higher up
       * in the tree, recurse downward.
       */
      for (i = 0; i < count; i++) {
            /*
             * Read the subsidiary block to see what we have to work with.
             * Don't do this in a transaction.  This is a depth-first
             * traversal of the tree so we may deal with many blocks
             * before we come back to this one.
             */
            error = xfs_da_read_buf(*trans, dp, child_fsb, -2, &child_bp,
                                    XFS_ATTR_FORK);
            if (error)
                  return(error);
            if (child_bp) {
                                    /* save for re-read later */
                  child_blkno = xfs_da_blkno(child_bp);

                  /*
                   * Invalidate the subtree, however we have to.
                   */
                  info = child_bp->data;
                  if (be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC) {
                        error = xfs_attr_node_inactive(trans, dp,
                                    child_bp, level+1);
                  } else if (be16_to_cpu(info->magic) == XFS_ATTR_LEAF_MAGIC) {
                        error = xfs_attr_leaf_inactive(trans, dp,
                                    child_bp);
                  } else {
                        error = XFS_ERROR(EIO);
                        xfs_da_brelse(*trans, child_bp);
                  }
                  if (error)
                        return(error);

                  /*
                   * Remove the subsidiary block from the cache
                   * and from the log.
                   */
                  error = xfs_da_get_buf(*trans, dp, 0, child_blkno,
                        &child_bp, XFS_ATTR_FORK);
                  if (error)
                        return(error);
                  xfs_da_binval(*trans, child_bp);
            }

            /*
             * If we're not done, re-read the parent to get the next
             * child block number.
             */
            if ((i+1) < count) {
                  error = xfs_da_read_buf(*trans, dp, 0, parent_blkno,
                        &bp, XFS_ATTR_FORK);
                  if (error)
                        return(error);
                  child_fsb = be32_to_cpu(node->btree[i+1].before);
                  xfs_da_brelse(*trans, bp);
            }
            /*
             * Atomically commit the whole invalidate stuff.
             */
            error = xfs_trans_roll(trans, dp);
            if (error)
                  return (error);
      }

      return(0);
}

/*
 * Invalidate all of the "remote" value regions pointed to by a particular
 * leaf block.
 * Note that we must release the lock on the buffer so that we are not
 * caught holding something that the logging code wants to flush to disk.
 */
STATIC int
xfs_attr_leaf_inactive(xfs_trans_t **trans, xfs_inode_t *dp, xfs_dabuf_t *bp)
{
      xfs_attr_leafblock_t *leaf;
      xfs_attr_leaf_entry_t *entry;
      xfs_attr_leaf_name_remote_t *name_rmt;
      xfs_attr_inactive_list_t *list, *lp;
      int error, count, size, tmp, i;

      leaf = bp->data;
      ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_ATTR_LEAF_MAGIC);

      /*
       * Count the number of "remote" value extents.
       */
      count = 0;
      entry = &leaf->entries[0];
      for (i = 0; i < be16_to_cpu(leaf->hdr.count); entry++, i++) {
            if (be16_to_cpu(entry->nameidx) &&
                ((entry->flags & XFS_ATTR_LOCAL) == 0)) {
                  name_rmt = xfs_attr_leaf_name_remote(leaf, i);
                  if (name_rmt->valueblk)
                        count++;
            }
      }

      /*
       * If there are no "remote" values, we're done.
       */
      if (count == 0) {
            xfs_da_brelse(*trans, bp);
            return(0);
      }

      /*
       * Allocate storage for a list of all the "remote" value extents.
       */
      size = count * sizeof(xfs_attr_inactive_list_t);
      list = (xfs_attr_inactive_list_t *)kmem_alloc(size, KM_SLEEP);

      /*
       * Identify each of the "remote" value extents.
       */
      lp = list;
      entry = &leaf->entries[0];
      for (i = 0; i < be16_to_cpu(leaf->hdr.count); entry++, i++) {
            if (be16_to_cpu(entry->nameidx) &&
                ((entry->flags & XFS_ATTR_LOCAL) == 0)) {
                  name_rmt = xfs_attr_leaf_name_remote(leaf, i);
                  if (name_rmt->valueblk) {
                        lp->valueblk = be32_to_cpu(name_rmt->valueblk);
                        lp->valuelen = XFS_B_TO_FSB(dp->i_mount,
                                        be32_to_cpu(name_rmt->valuelen));
                        lp++;
                  }
            }
      }
      xfs_da_brelse(*trans, bp);    /* unlock for trans. in freextent() */

      /*
       * Invalidate each of the "remote" value extents.
       */
      error = 0;
      for (lp = list, i = 0; i < count; i++, lp++) {
            tmp = xfs_attr_leaf_freextent(trans, dp,
                        lp->valueblk, lp->valuelen);

            if (error == 0)
                  error = tmp;      /* save only the 1st errno */
      }

      kmem_free((xfs_caddr_t)list);
      return(error);
}

/*
 * Look at all the extents for this logical region,
 * invalidate any buffers that are incore/in transactions.
 */
STATIC int
xfs_attr_leaf_freextent(xfs_trans_t **trans, xfs_inode_t *dp,
                            xfs_dablk_t blkno, int blkcnt)
{
      xfs_bmbt_irec_t map;
      xfs_dablk_t tblkno;
      int tblkcnt, dblkcnt, nmap, error;
      xfs_daddr_t dblkno;
      xfs_buf_t *bp;

      /*
       * Roll through the "value", invalidating the attribute value's
       * blocks.
       */
      tblkno = blkno;
      tblkcnt = blkcnt;
      while (tblkcnt > 0) {
            /*
             * Try to remember where we decided to put the value.
             */
            nmap = 1;
            error = xfs_bmapi(*trans, dp, (xfs_fileoff_t)tblkno, tblkcnt,
                              XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
                              NULL, 0, &map, &nmap, NULL, NULL);
            if (error) {
                  return(error);
            }
            ASSERT(nmap == 1);
            ASSERT(map.br_startblock != DELAYSTARTBLOCK);

            /*
             * If it's a hole, these are already unmapped
             * so there's nothing to invalidate.
             */
            if (map.br_startblock != HOLESTARTBLOCK) {

                  dblkno = XFS_FSB_TO_DADDR(dp->i_mount,
                                      map.br_startblock);
                  dblkcnt = XFS_FSB_TO_BB(dp->i_mount,
                                    map.br_blockcount);
                  bp = xfs_trans_get_buf(*trans,
                              dp->i_mount->m_ddev_targp,
                              dblkno, dblkcnt, XFS_BUF_LOCK);
                  xfs_trans_binval(*trans, bp);
                  /*
                   * Roll to next transaction.
                   */
                  error = xfs_trans_roll(trans, dp);
                  if (error)
                        return (error);
            }

            tblkno += map.br_blockcount;
            tblkcnt -= map.br_blockcount;
      }

      return(0);
}

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