xfs_dir2_sf.c

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/*
 * Copyright (c) 2000-2003,2005 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_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_error.h"
#include "xfs_dir2.h"
#include "xfs_dir2_format.h"
#include "xfs_dir2_priv.h"
#include "xfs_trace.h"

/*
 * Prototypes for internal functions.
 */
static void xfs_dir2_sf_addname_easy(xfs_da_args_t *args,
                     xfs_dir2_sf_entry_t *sfep,
                     xfs_dir2_data_aoff_t offset,
                     int new_isize);
static void xfs_dir2_sf_addname_hard(xfs_da_args_t *args, int objchange,
                     int new_isize);
static int xfs_dir2_sf_addname_pick(xfs_da_args_t *args, int objchange,
                    xfs_dir2_sf_entry_t **sfepp,
                    xfs_dir2_data_aoff_t *offsetp);
#ifdef DEBUG
static void xfs_dir2_sf_check(xfs_da_args_t *args);
#else
#define xfs_dir2_sf_check(args)
#endif /* DEBUG */
#if XFS_BIG_INUMS
static void xfs_dir2_sf_toino4(xfs_da_args_t *args);
static void xfs_dir2_sf_toino8(xfs_da_args_t *args);
#endif /* XFS_BIG_INUMS */

/*
 * Inode numbers in short-form directories can come in two versions,
 * either 4 bytes or 8 bytes wide.  These helpers deal with the
 * two forms transparently by looking at the headers i8count field.
 *
 * For 64-bit inode number the most significant byte must be zero.
 */
static xfs_ino_t
xfs_dir2_sf_get_ino(
    struct xfs_dir2_sf_hdr  *hdr,
    xfs_dir2_inou_t     *from)
{
    if (hdr->i8count)
        return get_unaligned_be64(&from->i8.i) & 0x00ffffffffffffffULL;
    else
        return get_unaligned_be32(&from->i4.i);
}

static void
xfs_dir2_sf_put_ino(
    struct xfs_dir2_sf_hdr  *hdr,
    xfs_dir2_inou_t     *to,
    xfs_ino_t       ino)
{
    ASSERT((ino & 0xff00000000000000ULL) == 0);

    if (hdr->i8count)
        put_unaligned_be64(ino, &to->i8.i);
    else
        put_unaligned_be32(ino, &to->i4.i);
}

xfs_ino_t
xfs_dir2_sf_get_parent_ino(
    struct xfs_dir2_sf_hdr  *hdr)
{
    return xfs_dir2_sf_get_ino(hdr, &hdr->parent);
}

static void
xfs_dir2_sf_put_parent_ino(
    struct xfs_dir2_sf_hdr  *hdr,
    xfs_ino_t       ino)
{
    xfs_dir2_sf_put_ino(hdr, &hdr->parent, ino);
}

/*
 * In short-form directory entries the inode numbers are stored at variable
 * offset behind the entry name.  The inode numbers may only be accessed
 * through the helpers below.
 */
static xfs_dir2_inou_t *
xfs_dir2_sfe_inop(
    struct xfs_dir2_sf_entry *sfep)
{
    return (xfs_dir2_inou_t *)&sfep->name[sfep->namelen];
}

xfs_ino_t
xfs_dir2_sfe_get_ino(
    struct xfs_dir2_sf_hdr  *hdr,
    struct xfs_dir2_sf_entry *sfep)
{
    return xfs_dir2_sf_get_ino(hdr, xfs_dir2_sfe_inop(sfep));
}

static void
xfs_dir2_sfe_put_ino(
    struct xfs_dir2_sf_hdr  *hdr,
    struct xfs_dir2_sf_entry *sfep,
    xfs_ino_t       ino)
{
    xfs_dir2_sf_put_ino(hdr, xfs_dir2_sfe_inop(sfep), ino);
}

/*
 * Given a block directory (dp/block), calculate its size as a shortform (sf)
 * directory and a header for the sf directory, if it will fit it the
 * space currently present in the inode.  If it won't fit, the output
 * size is too big (but not accurate).
 */
int                     /* size for sf form */
xfs_dir2_block_sfsize(
    xfs_inode_t     *dp,        /* incore inode pointer */
    xfs_dir2_data_hdr_t *hdr,       /* block directory data */
    xfs_dir2_sf_hdr_t   *sfhp)      /* output: header for sf form */
{
    xfs_dir2_dataptr_t  addr;       /* data entry address */
    xfs_dir2_leaf_entry_t   *blp;       /* leaf area of the block */
    xfs_dir2_block_tail_t   *btp;       /* tail area of the block */
    int         count;      /* shortform entry count */
    xfs_dir2_data_entry_t   *dep;       /* data entry in the block */
    int         i;      /* block entry index */
    int         i8count;    /* count of big-inode entries */
    int         isdot;      /* entry is "." */
    int         isdotdot;   /* entry is ".." */
    xfs_mount_t     *mp;        /* mount structure pointer */
    int         namelen;    /* total name bytes */
    xfs_ino_t       parent = 0; /* parent inode number */
    int         size=0;     /* total computed size */

    mp = dp->i_mount;

    count = i8count = namelen = 0;
    btp = xfs_dir2_block_tail_p(mp, hdr);
    blp = xfs_dir2_block_leaf_p(btp);

    /*
     * Iterate over the block's data entries by using the leaf pointers.
     */
    for (i = 0; i < be32_to_cpu(btp->count); i++) {
        if ((addr = be32_to_cpu(blp[i].address)) == XFS_DIR2_NULL_DATAPTR)
            continue;
        /*
         * Calculate the pointer to the entry at hand.
         */
        dep = (xfs_dir2_data_entry_t *)
              ((char *)hdr + xfs_dir2_dataptr_to_off(mp, addr));
        /*
         * Detect . and .., so we can special-case them.
         * . is not included in sf directories.
         * .. is included by just the parent inode number.
         */
        isdot = dep->namelen == 1 && dep->name[0] == '.';
        isdotdot =
            dep->namelen == 2 &&
            dep->name[0] == '.' && dep->name[1] == '.';
#if XFS_BIG_INUMS
        if (!isdot)
            i8count += be64_to_cpu(dep->inumber) > XFS_DIR2_MAX_SHORT_INUM;
#endif
        if (!isdot && !isdotdot) {
            count++;
            namelen += dep->namelen;
        } else if (isdotdot)
            parent = be64_to_cpu(dep->inumber);
        /*
         * Calculate the new size, see if we should give up yet.
         */
        size = xfs_dir2_sf_hdr_size(i8count) +      /* header */
               count +                  /* namelen */
               count * (uint)sizeof(xfs_dir2_sf_off_t) + /* offset */
               namelen +                /* name */
               (i8count ?               /* inumber */
                (uint)sizeof(xfs_dir2_ino8_t) * count :
                (uint)sizeof(xfs_dir2_ino4_t) * count);
        if (size > XFS_IFORK_DSIZE(dp))
            return size;        /* size value is a failure */
    }
    /*
     * Create the output header, if it worked.
     */
    sfhp->count = count;
    sfhp->i8count = i8count;
    xfs_dir2_sf_put_parent_ino(sfhp, parent);
    return size;
}

/*
 * Convert a block format directory to shortform.
 * Caller has already checked that it will fit, and built us a header.
 */
int                     /* error */
xfs_dir2_block_to_sf(
    xfs_da_args_t       *args,      /* operation arguments */
    struct xfs_buf      *bp,
    int         size,       /* shortform directory size */
    xfs_dir2_sf_hdr_t   *sfhp)      /* shortform directory hdr */
{
    xfs_dir2_data_hdr_t *hdr;       /* block header */
    xfs_dir2_block_tail_t   *btp;       /* block tail pointer */
    xfs_dir2_data_entry_t   *dep;       /* data entry pointer */
    xfs_inode_t     *dp;        /* incore directory inode */
    xfs_dir2_data_unused_t  *dup;       /* unused data pointer */
    char            *endptr;    /* end of data entries */
    int         error;      /* error return value */
    int         logflags;   /* inode logging flags */
    xfs_mount_t     *mp;        /* filesystem mount point */
    char            *ptr;       /* current data pointer */
    xfs_dir2_sf_entry_t *sfep;      /* shortform entry */
    xfs_dir2_sf_hdr_t   *sfp;       /* shortform directory header */

    trace_xfs_dir2_block_to_sf(args);

    dp = args->dp;
    mp = dp->i_mount;

    /*
     * Make a copy of the block data, so we can shrink the inode
     * and add local data.
     */
    hdr = kmem_alloc(mp->m_dirblksize, KM_SLEEP);
    memcpy(hdr, bp->b_addr, mp->m_dirblksize);
    logflags = XFS_ILOG_CORE;
    if ((error = xfs_dir2_shrink_inode(args, mp->m_dirdatablk, bp))) {
        ASSERT(error != ENOSPC);
        goto out;
    }

    /*
     * The buffer is now unconditionally gone, whether
     * xfs_dir2_shrink_inode worked or not.
     *
     * Convert the inode to local format.
     */
    dp->i_df.if_flags &= ~XFS_IFEXTENTS;
    dp->i_df.if_flags |= XFS_IFINLINE;
    dp->i_d.di_format = XFS_DINODE_FMT_LOCAL;
    ASSERT(dp->i_df.if_bytes == 0);
    xfs_idata_realloc(dp, size, XFS_DATA_FORK);
    logflags |= XFS_ILOG_DDATA;
    /*
     * Copy the header into the newly allocate local space.
     */
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    memcpy(sfp, sfhp, xfs_dir2_sf_hdr_size(sfhp->i8count));
    dp->i_d.di_size = size;
    /*
     * Set up to loop over the block's entries.
     */
    btp = xfs_dir2_block_tail_p(mp, hdr);
    ptr = (char *)(hdr + 1);
    endptr = (char *)xfs_dir2_block_leaf_p(btp);
    sfep = xfs_dir2_sf_firstentry(sfp);
    /*
     * Loop over the active and unused entries.
     * Stop when we reach the leaf/tail portion of the block.
     */
    while (ptr < endptr) {
        /*
         * If it's unused, just skip over it.
         */
        dup = (xfs_dir2_data_unused_t *)ptr;
        if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
            ptr += be16_to_cpu(dup->length);
            continue;
        }
        dep = (xfs_dir2_data_entry_t *)ptr;
        /*
         * Skip .
         */
        if (dep->namelen == 1 && dep->name[0] == '.')
            ASSERT(be64_to_cpu(dep->inumber) == dp->i_ino);
        /*
         * Skip .., but make sure the inode number is right.
         */
        else if (dep->namelen == 2 &&
             dep->name[0] == '.' && dep->name[1] == '.')
            ASSERT(be64_to_cpu(dep->inumber) ==
                   xfs_dir2_sf_get_parent_ino(sfp));
        /*
         * Normal entry, copy it into shortform.
         */
        else {
            sfep->namelen = dep->namelen;
            xfs_dir2_sf_put_offset(sfep,
                (xfs_dir2_data_aoff_t)
                ((char *)dep - (char *)hdr));
            memcpy(sfep->name, dep->name, dep->namelen);
            xfs_dir2_sfe_put_ino(sfp, sfep,
                         be64_to_cpu(dep->inumber));

            sfep = xfs_dir2_sf_nextentry(sfp, sfep);
        }
        ptr += xfs_dir2_data_entsize(dep->namelen);
    }
    ASSERT((char *)sfep - (char *)sfp == size);
    xfs_dir2_sf_check(args);
out:
    xfs_trans_log_inode(args->trans, dp, logflags);
    kmem_free(hdr);
    return error;
}

/*
 * Add a name to a shortform directory.
 * There are two algorithms, "easy" and "hard" which we decide on
 * before changing anything.
 * Convert to block form if necessary, if the new entry won't fit.
 */
int                     /* error */
xfs_dir2_sf_addname(
    xfs_da_args_t       *args)      /* operation arguments */
{
    int         add_entsize;    /* size of the new entry */
    xfs_inode_t     *dp;        /* incore directory inode */
    int         error;      /* error return value */
    int         incr_isize; /* total change in size */
    int         new_isize;  /* di_size after adding name */
    int         objchange;  /* changing to 8-byte inodes */
    xfs_dir2_data_aoff_t    offset = 0; /* offset for new entry */
    int         old_isize;  /* di_size before adding name */
    int         pick;       /* which algorithm to use */
    xfs_dir2_sf_hdr_t   *sfp;       /* shortform structure */
    xfs_dir2_sf_entry_t *sfep = NULL;   /* shortform entry */

    trace_xfs_dir2_sf_addname(args);

    ASSERT(xfs_dir2_sf_lookup(args) == ENOENT);
    dp = args->dp;
    ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
    /*
     * Make sure the shortform value has some of its header.
     */
    if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) {
        ASSERT(XFS_FORCED_SHUTDOWN(dp->i_mount));
        return XFS_ERROR(EIO);
    }
    ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
    ASSERT(dp->i_df.if_u1.if_data != NULL);
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->i8count));
    /*
     * Compute entry (and change in) size.
     */
    add_entsize = xfs_dir2_sf_entsize(sfp, args->namelen);
    incr_isize = add_entsize;
    objchange = 0;
#if XFS_BIG_INUMS
    /*
     * Do we have to change to 8 byte inodes?
     */
    if (args->inumber > XFS_DIR2_MAX_SHORT_INUM && sfp->i8count == 0) {
        /*
         * Yes, adjust the entry size and the total size.
         */
        add_entsize +=
            (uint)sizeof(xfs_dir2_ino8_t) -
            (uint)sizeof(xfs_dir2_ino4_t);
        incr_isize +=
            (sfp->count + 2) *
            ((uint)sizeof(xfs_dir2_ino8_t) -
             (uint)sizeof(xfs_dir2_ino4_t));
        objchange = 1;
    }
#endif
    old_isize = (int)dp->i_d.di_size;
    new_isize = old_isize + incr_isize;
    /*
     * Won't fit as shortform any more (due to size),
     * or the pick routine says it won't (due to offset values).
     */
    if (new_isize > XFS_IFORK_DSIZE(dp) ||
        (pick =
         xfs_dir2_sf_addname_pick(args, objchange, &sfep, &offset)) == 0) {
        /*
         * Just checking or no space reservation, it doesn't fit.
         */
        if ((args->op_flags & XFS_DA_OP_JUSTCHECK) || args->total == 0)
            return XFS_ERROR(ENOSPC);
        /*
         * Convert to block form then add the name.
         */
        error = xfs_dir2_sf_to_block(args);
        if (error)
            return error;
        return xfs_dir2_block_addname(args);
    }
    /*
     * Just checking, it fits.
     */
    if (args->op_flags & XFS_DA_OP_JUSTCHECK)
        return 0;
    /*
     * Do it the easy way - just add it at the end.
     */
    if (pick == 1)
        xfs_dir2_sf_addname_easy(args, sfep, offset, new_isize);
    /*
     * Do it the hard way - look for a place to insert the new entry.
     * Convert to 8 byte inode numbers first if necessary.
     */
    else {
        ASSERT(pick == 2);
#if XFS_BIG_INUMS
        if (objchange)
            xfs_dir2_sf_toino8(args);
#endif
        xfs_dir2_sf_addname_hard(args, objchange, new_isize);
    }
    xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);
    return 0;
}

/*
 * Add the new entry the "easy" way.
 * This is copying the old directory and adding the new entry at the end.
 * Since it's sorted by "offset" we need room after the last offset
 * that's already there, and then room to convert to a block directory.
 * This is already checked by the pick routine.
 */
static void
xfs_dir2_sf_addname_easy(
    xfs_da_args_t       *args,      /* operation arguments */
    xfs_dir2_sf_entry_t *sfep,      /* pointer to new entry */
    xfs_dir2_data_aoff_t    offset,     /* offset to use for new ent */
    int         new_isize)  /* new directory size */
{
    int         byteoff;    /* byte offset in sf dir */
    xfs_inode_t     *dp;        /* incore directory inode */
    xfs_dir2_sf_hdr_t   *sfp;       /* shortform structure */

    dp = args->dp;

    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    byteoff = (int)((char *)sfep - (char *)sfp);
    /*
     * Grow the in-inode space.
     */
    xfs_idata_realloc(dp, xfs_dir2_sf_entsize(sfp, args->namelen),
        XFS_DATA_FORK);
    /*
     * Need to set up again due to realloc of the inode data.
     */
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    sfep = (xfs_dir2_sf_entry_t *)((char *)sfp + byteoff);
    /*
     * Fill in the new entry.
     */
    sfep->namelen = args->namelen;
    xfs_dir2_sf_put_offset(sfep, offset);
    memcpy(sfep->name, args->name, sfep->namelen);
    xfs_dir2_sfe_put_ino(sfp, sfep, args->inumber);
    /*
     * Update the header and inode.
     */
    sfp->count++;
#if XFS_BIG_INUMS
    if (args->inumber > XFS_DIR2_MAX_SHORT_INUM)
        sfp->i8count++;
#endif
    dp->i_d.di_size = new_isize;
    xfs_dir2_sf_check(args);
}

/*
 * Add the new entry the "hard" way.
 * The caller has already converted to 8 byte inode numbers if necessary,
 * in which case we need to leave the i8count at 1.
 * Find a hole that the new entry will fit into, and copy
 * the first part of the entries, the new entry, and the last part of
 * the entries.
 */
/* ARGSUSED */
static void
xfs_dir2_sf_addname_hard(
    xfs_da_args_t       *args,      /* operation arguments */
    int         objchange,  /* changing inode number size */
    int         new_isize)  /* new directory size */
{
    int         add_datasize;   /* data size need for new ent */
    char            *buf;       /* buffer for old */
    xfs_inode_t     *dp;        /* incore directory inode */
    int         eof;        /* reached end of old dir */
    int         nbytes;     /* temp for byte copies */
    xfs_dir2_data_aoff_t    new_offset; /* next offset value */
    xfs_dir2_data_aoff_t    offset;     /* current offset value */
    int         old_isize;  /* previous di_size */
    xfs_dir2_sf_entry_t *oldsfep;   /* entry in original dir */
    xfs_dir2_sf_hdr_t   *oldsfp;    /* original shortform dir */
    xfs_dir2_sf_entry_t *sfep;      /* entry in new dir */
    xfs_dir2_sf_hdr_t   *sfp;       /* new shortform dir */

    /*
     * Copy the old directory to the stack buffer.
     */
    dp = args->dp;

    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    old_isize = (int)dp->i_d.di_size;
    buf = kmem_alloc(old_isize, KM_SLEEP);
    oldsfp = (xfs_dir2_sf_hdr_t *)buf;
    memcpy(oldsfp, sfp, old_isize);
    /*
     * Loop over the old directory finding the place we're going
     * to insert the new entry.
     * If it's going to end up at the end then oldsfep will point there.
     */
    for (offset = XFS_DIR2_DATA_FIRST_OFFSET,
          oldsfep = xfs_dir2_sf_firstentry(oldsfp),
          add_datasize = xfs_dir2_data_entsize(args->namelen),
          eof = (char *)oldsfep == &buf[old_isize];
         !eof;
         offset = new_offset + xfs_dir2_data_entsize(oldsfep->namelen),
          oldsfep = xfs_dir2_sf_nextentry(oldsfp, oldsfep),
          eof = (char *)oldsfep == &buf[old_isize]) {
        new_offset = xfs_dir2_sf_get_offset(oldsfep);
        if (offset + add_datasize <= new_offset)
            break;
    }
    /*
     * Get rid of the old directory, then allocate space for
     * the new one.  We do this so xfs_idata_realloc won't copy
     * the data.
     */
    xfs_idata_realloc(dp, -old_isize, XFS_DATA_FORK);
    xfs_idata_realloc(dp, new_isize, XFS_DATA_FORK);
    /*
     * Reset the pointer since the buffer was reallocated.
     */
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    /*
     * Copy the first part of the directory, including the header.
     */
    nbytes = (int)((char *)oldsfep - (char *)oldsfp);
    memcpy(sfp, oldsfp, nbytes);
    sfep = (xfs_dir2_sf_entry_t *)((char *)sfp + nbytes);
    /*
     * Fill in the new entry, and update the header counts.
     */
    sfep->namelen = args->namelen;
    xfs_dir2_sf_put_offset(sfep, offset);
    memcpy(sfep->name, args->name, sfep->namelen);
    xfs_dir2_sfe_put_ino(sfp, sfep, args->inumber);
    sfp->count++;
#if XFS_BIG_INUMS
    if (args->inumber > XFS_DIR2_MAX_SHORT_INUM && !objchange)
        sfp->i8count++;
#endif
    /*
     * If there's more left to copy, do that.
     */
    if (!eof) {
        sfep = xfs_dir2_sf_nextentry(sfp, sfep);
        memcpy(sfep, oldsfep, old_isize - nbytes);
    }
    kmem_free(buf);
    dp->i_d.di_size = new_isize;
    xfs_dir2_sf_check(args);
}

/*
 * Decide if the new entry will fit at all.
 * If it will fit, pick between adding the new entry to the end (easy)
 * or somewhere else (hard).
 * Return 0 (won't fit), 1 (easy), 2 (hard).
 */
/*ARGSUSED*/
static int                  /* pick result */
xfs_dir2_sf_addname_pick(
    xfs_da_args_t       *args,      /* operation arguments */
    int         objchange,  /* inode # size changes */
    xfs_dir2_sf_entry_t **sfepp,    /* out(1): new entry ptr */
    xfs_dir2_data_aoff_t    *offsetp)   /* out(1): new offset */
{
    xfs_inode_t     *dp;        /* incore directory inode */
    int         holefit;    /* found hole it will fit in */
    int         i;      /* entry number */
    xfs_mount_t     *mp;        /* filesystem mount point */
    xfs_dir2_data_aoff_t    offset;     /* data block offset */
    xfs_dir2_sf_entry_t *sfep;      /* shortform entry */
    xfs_dir2_sf_hdr_t   *sfp;       /* shortform structure */
    int         size;       /* entry's data size */
    int         used;       /* data bytes used */

    dp = args->dp;
    mp = dp->i_mount;

    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    size = xfs_dir2_data_entsize(args->namelen);
    offset = XFS_DIR2_DATA_FIRST_OFFSET;
    sfep = xfs_dir2_sf_firstentry(sfp);
    holefit = 0;
    /*
     * Loop over sf entries.
     * Keep track of data offset and whether we've seen a place
     * to insert the new entry.
     */
    for (i = 0; i < sfp->count; i++) {
        if (!holefit)
            holefit = offset + size <= xfs_dir2_sf_get_offset(sfep);
        offset = xfs_dir2_sf_get_offset(sfep) +
             xfs_dir2_data_entsize(sfep->namelen);
        sfep = xfs_dir2_sf_nextentry(sfp, sfep);
    }
    /*
     * Calculate data bytes used excluding the new entry, if this
     * was a data block (block form directory).
     */
    used = offset +
           (sfp->count + 3) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
           (uint)sizeof(xfs_dir2_block_tail_t);
    /*
     * If it won't fit in a block form then we can't insert it,
     * we'll go back, convert to block, then try the insert and convert
     * to leaf.
     */
    if (used + (holefit ? 0 : size) > mp->m_dirblksize)
        return 0;
    /*
     * If changing the inode number size, do it the hard way.
     */
#if XFS_BIG_INUMS
    if (objchange) {
        return 2;
    }
#else
    ASSERT(objchange == 0);
#endif
    /*
     * If it won't fit at the end then do it the hard way (use the hole).
     */
    if (used + size > mp->m_dirblksize)
        return 2;
    /*
     * Do it the easy way.
     */
    *sfepp = sfep;
    *offsetp = offset;
    return 1;
}

#ifdef DEBUG
/*
 * Check consistency of shortform directory, assert if bad.
 */
static void
xfs_dir2_sf_check(
    xfs_da_args_t       *args)      /* operation arguments */
{
    xfs_inode_t     *dp;        /* incore directory inode */
    int         i;      /* entry number */
    int         i8count;    /* number of big inode#s */
    xfs_ino_t       ino;        /* entry inode number */
    int         offset;     /* data offset */
    xfs_dir2_sf_entry_t *sfep;      /* shortform dir entry */
    xfs_dir2_sf_hdr_t   *sfp;       /* shortform structure */

    dp = args->dp;

    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    offset = XFS_DIR2_DATA_FIRST_OFFSET;
    ino = xfs_dir2_sf_get_parent_ino(sfp);
    i8count = ino > XFS_DIR2_MAX_SHORT_INUM;

    for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp);
         i < sfp->count;
         i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) {
        ASSERT(xfs_dir2_sf_get_offset(sfep) >= offset);
        ino = xfs_dir2_sfe_get_ino(sfp, sfep);
        i8count += ino > XFS_DIR2_MAX_SHORT_INUM;
        offset =
            xfs_dir2_sf_get_offset(sfep) +
            xfs_dir2_data_entsize(sfep->namelen);
    }
    ASSERT(i8count == sfp->i8count);
    ASSERT(XFS_BIG_INUMS || i8count == 0);
    ASSERT((char *)sfep - (char *)sfp == dp->i_d.di_size);
    ASSERT(offset +
           (sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
           (uint)sizeof(xfs_dir2_block_tail_t) <=
           dp->i_mount->m_dirblksize);
}
#endif  /* DEBUG */

/*
 * Create a new (shortform) directory.
 */
int                 /* error, always 0 */
xfs_dir2_sf_create(
    xfs_da_args_t   *args,      /* operation arguments */
    xfs_ino_t   pino)       /* parent inode number */
{
    xfs_inode_t *dp;        /* incore directory inode */
    int     i8count;    /* parent inode is an 8-byte number */
    xfs_dir2_sf_hdr_t *sfp;     /* shortform structure */
    int     size;       /* directory size */

    trace_xfs_dir2_sf_create(args);

    dp = args->dp;

    ASSERT(dp != NULL);
    ASSERT(dp->i_d.di_size == 0);
    /*
     * If it's currently a zero-length extent file,
     * convert it to local format.
     */
    if (dp->i_d.di_format == XFS_DINODE_FMT_EXTENTS) {
        dp->i_df.if_flags &= ~XFS_IFEXTENTS;    /* just in case */
        dp->i_d.di_format = XFS_DINODE_FMT_LOCAL;
        xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
        dp->i_df.if_flags |= XFS_IFINLINE;
    }
    ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
    ASSERT(dp->i_df.if_bytes == 0);
    i8count = pino > XFS_DIR2_MAX_SHORT_INUM;
    size = xfs_dir2_sf_hdr_size(i8count);
    /*
     * Make a buffer for the data.
     */
    xfs_idata_realloc(dp, size, XFS_DATA_FORK);
    /*
     * Fill in the header,
     */
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    sfp->i8count = i8count;
    /*
     * Now can put in the inode number, since i8count is set.
     */
    xfs_dir2_sf_put_parent_ino(sfp, pino);
    sfp->count = 0;
    dp->i_d.di_size = size;
    xfs_dir2_sf_check(args);
    xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);
    return 0;
}

int                     /* error */
xfs_dir2_sf_getdents(
    xfs_inode_t     *dp,        /* incore directory inode */
    void            *dirent,
    xfs_off_t       *offset,
    filldir_t       filldir)
{
    int         i;      /* shortform entry number */
    xfs_mount_t     *mp;        /* filesystem mount point */
    xfs_dir2_dataptr_t  off;        /* current entry's offset */
    xfs_dir2_sf_entry_t *sfep;      /* shortform directory entry */
    xfs_dir2_sf_hdr_t   *sfp;       /* shortform structure */
    xfs_dir2_dataptr_t  dot_offset;
    xfs_dir2_dataptr_t  dotdot_offset;
    xfs_ino_t       ino;

    mp = dp->i_mount;

    ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
    /*
     * Give up if the directory is way too short.
     */
    if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) {
        ASSERT(XFS_FORCED_SHUTDOWN(mp));
        return XFS_ERROR(EIO);
    }

    ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
    ASSERT(dp->i_df.if_u1.if_data != NULL);

    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;

    ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->i8count));

    /*
     * If the block number in the offset is out of range, we're done.
     */
    if (xfs_dir2_dataptr_to_db(mp, *offset) > mp->m_dirdatablk)
        return 0;

    /*
     * Precalculate offsets for . and .. as we will always need them.
     *
     * XXX(hch): the second argument is sometimes 0 and sometimes
     * mp->m_dirdatablk.
     */
    dot_offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
                         XFS_DIR2_DATA_DOT_OFFSET);
    dotdot_offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
                        XFS_DIR2_DATA_DOTDOT_OFFSET);

    /*
     * Put . entry unless we're starting past it.
     */
    if (*offset <= dot_offset) {
        if (filldir(dirent, ".", 1, dot_offset & 0x7fffffff, dp->i_ino, DT_DIR)) {
            *offset = dot_offset & 0x7fffffff;
            return 0;
        }
    }

    /*
     * Put .. entry unless we're starting past it.
     */
    if (*offset <= dotdot_offset) {
        ino = xfs_dir2_sf_get_parent_ino(sfp);
        if (filldir(dirent, "..", 2, dotdot_offset & 0x7fffffff, ino, DT_DIR)) {
            *offset = dotdot_offset & 0x7fffffff;
            return 0;
        }
    }

    /*
     * Loop while there are more entries and put'ing works.
     */
    sfep = xfs_dir2_sf_firstentry(sfp);
    for (i = 0; i < sfp->count; i++) {
        off = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
                xfs_dir2_sf_get_offset(sfep));

        if (*offset > off) {
            sfep = xfs_dir2_sf_nextentry(sfp, sfep);
            continue;
        }

        ino = xfs_dir2_sfe_get_ino(sfp, sfep);
        if (filldir(dirent, (char *)sfep->name, sfep->namelen,
                off & 0x7fffffff, ino, DT_UNKNOWN)) {
            *offset = off & 0x7fffffff;
            return 0;
        }
        sfep = xfs_dir2_sf_nextentry(sfp, sfep);
    }

    *offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) &
            0x7fffffff;
    return 0;
}

/*
 * Lookup an entry in a shortform directory.
 * Returns EEXIST if found, ENOENT if not found.
 */
int                     /* error */
xfs_dir2_sf_lookup(
    xfs_da_args_t       *args)      /* operation arguments */
{
    xfs_inode_t     *dp;        /* incore directory inode */
    int         i;      /* entry index */
    int         error;
    xfs_dir2_sf_entry_t *sfep;      /* shortform directory entry */
    xfs_dir2_sf_hdr_t   *sfp;       /* shortform structure */
    enum xfs_dacmp      cmp;        /* comparison result */
    xfs_dir2_sf_entry_t *ci_sfep;   /* case-insens. entry */

    trace_xfs_dir2_sf_lookup(args);

    xfs_dir2_sf_check(args);
    dp = args->dp;

    ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
    /*
     * Bail out if the directory is way too short.
     */
    if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) {
        ASSERT(XFS_FORCED_SHUTDOWN(dp->i_mount));
        return XFS_ERROR(EIO);
    }
    ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
    ASSERT(dp->i_df.if_u1.if_data != NULL);
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->i8count));
    /*
     * Special case for .
     */
    if (args->namelen == 1 && args->name[0] == '.') {
        args->inumber = dp->i_ino;
        args->cmpresult = XFS_CMP_EXACT;
        return XFS_ERROR(EEXIST);
    }
    /*
     * Special case for ..
     */
    if (args->namelen == 2 &&
        args->name[0] == '.' && args->name[1] == '.') {
        args->inumber = xfs_dir2_sf_get_parent_ino(sfp);
        args->cmpresult = XFS_CMP_EXACT;
        return XFS_ERROR(EEXIST);
    }
    /*
     * Loop over all the entries trying to match ours.
     */
    ci_sfep = NULL;
    for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp); i < sfp->count;
                i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) {
        /*
         * Compare name and if it's an exact match, return the inode
         * number. If it's the first case-insensitive match, store the
         * inode number and continue looking for an exact match.
         */
        cmp = dp->i_mount->m_dirnameops->compname(args, sfep->name,
                                sfep->namelen);
        if (cmp != XFS_CMP_DIFFERENT && cmp != args->cmpresult) {
            args->cmpresult = cmp;
            args->inumber = xfs_dir2_sfe_get_ino(sfp, sfep);
            if (cmp == XFS_CMP_EXACT)
                return XFS_ERROR(EEXIST);
            ci_sfep = sfep;
        }
    }
    ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
    /*
     * Here, we can only be doing a lookup (not a rename or replace).
     * If a case-insensitive match was not found, return ENOENT.
     */
    if (!ci_sfep)
        return XFS_ERROR(ENOENT);
    /* otherwise process the CI match as required by the caller */
    error = xfs_dir_cilookup_result(args, ci_sfep->name, ci_sfep->namelen);
    return XFS_ERROR(error);
}

/*
 * Remove an entry from a shortform directory.
 */
int                     /* error */
xfs_dir2_sf_removename(
    xfs_da_args_t       *args)
{
    int         byteoff;    /* offset of removed entry */
    xfs_inode_t     *dp;        /* incore directory inode */
    int         entsize;    /* this entry's size */
    int         i;      /* shortform entry index */
    int         newsize;    /* new inode size */
    int         oldsize;    /* old inode size */
    xfs_dir2_sf_entry_t *sfep;      /* shortform directory entry */
    xfs_dir2_sf_hdr_t   *sfp;       /* shortform structure */

    trace_xfs_dir2_sf_removename(args);

    dp = args->dp;

    ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
    oldsize = (int)dp->i_d.di_size;
    /*
     * Bail out if the directory is way too short.
     */
    if (oldsize < offsetof(xfs_dir2_sf_hdr_t, parent)) {
        ASSERT(XFS_FORCED_SHUTDOWN(dp->i_mount));
        return XFS_ERROR(EIO);
    }
    ASSERT(dp->i_df.if_bytes == oldsize);
    ASSERT(dp->i_df.if_u1.if_data != NULL);
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    ASSERT(oldsize >= xfs_dir2_sf_hdr_size(sfp->i8count));
    /*
     * Loop over the old directory entries.
     * Find the one we're deleting.
     */
    for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp); i < sfp->count;
                i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) {
        if (xfs_da_compname(args, sfep->name, sfep->namelen) ==
                                XFS_CMP_EXACT) {
            ASSERT(xfs_dir2_sfe_get_ino(sfp, sfep) ==
                   args->inumber);
            break;
        }
    }
    /*
     * Didn't find it.
     */
    if (i == sfp->count)
        return XFS_ERROR(ENOENT);
    /*
     * Calculate sizes.
     */
    byteoff = (int)((char *)sfep - (char *)sfp);
    entsize = xfs_dir2_sf_entsize(sfp, args->namelen);
    newsize = oldsize - entsize;
    /*
     * Copy the part if any after the removed entry, sliding it down.
     */
    if (byteoff + entsize < oldsize)
        memmove((char *)sfp + byteoff, (char *)sfp + byteoff + entsize,
            oldsize - (byteoff + entsize));
    /*
     * Fix up the header and file size.
     */
    sfp->count--;
    dp->i_d.di_size = newsize;
    /*
     * Reallocate, making it smaller.
     */
    xfs_idata_realloc(dp, newsize - oldsize, XFS_DATA_FORK);
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
#if XFS_BIG_INUMS
    /*
     * Are we changing inode number size?
     */
    if (args->inumber > XFS_DIR2_MAX_SHORT_INUM) {
        if (sfp->i8count == 1)
            xfs_dir2_sf_toino4(args);
        else
            sfp->i8count--;
    }
#endif
    xfs_dir2_sf_check(args);
    xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);
    return 0;
}

/*
 * Replace the inode number of an entry in a shortform directory.
 */
int                     /* error */
xfs_dir2_sf_replace(
    xfs_da_args_t       *args)      /* operation arguments */
{
    xfs_inode_t     *dp;        /* incore directory inode */
    int         i;      /* entry index */
#if XFS_BIG_INUMS || defined(DEBUG)
    xfs_ino_t       ino=0;      /* entry old inode number */
#endif
#if XFS_BIG_INUMS
    int         i8elevated; /* sf_toino8 set i8count=1 */
#endif
    xfs_dir2_sf_entry_t *sfep;      /* shortform directory entry */
    xfs_dir2_sf_hdr_t   *sfp;       /* shortform structure */

    trace_xfs_dir2_sf_replace(args);

    dp = args->dp;

    ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
    /*
     * Bail out if the shortform directory is way too small.
     */
    if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) {
        ASSERT(XFS_FORCED_SHUTDOWN(dp->i_mount));
        return XFS_ERROR(EIO);
    }
    ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
    ASSERT(dp->i_df.if_u1.if_data != NULL);
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->i8count));
#if XFS_BIG_INUMS
    /*
     * New inode number is large, and need to convert to 8-byte inodes.
     */
    if (args->inumber > XFS_DIR2_MAX_SHORT_INUM && sfp->i8count == 0) {
        int error;          /* error return value */
        int newsize;        /* new inode size */

        newsize =
            dp->i_df.if_bytes +
            (sfp->count + 1) *
            ((uint)sizeof(xfs_dir2_ino8_t) -
             (uint)sizeof(xfs_dir2_ino4_t));
        /*
         * Won't fit as shortform, convert to block then do replace.
         */
        if (newsize > XFS_IFORK_DSIZE(dp)) {
            error = xfs_dir2_sf_to_block(args);
            if (error) {
                return error;
            }
            return xfs_dir2_block_replace(args);
        }
        /*
         * Still fits, convert to 8-byte now.
         */
        xfs_dir2_sf_toino8(args);
        i8elevated = 1;
        sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    } else
        i8elevated = 0;
#endif
    ASSERT(args->namelen != 1 || args->name[0] != '.');
    /*
     * Replace ..'s entry.
     */
    if (args->namelen == 2 &&
        args->name[0] == '.' && args->name[1] == '.') {
#if XFS_BIG_INUMS || defined(DEBUG)
        ino = xfs_dir2_sf_get_parent_ino(sfp);
        ASSERT(args->inumber != ino);
#endif
        xfs_dir2_sf_put_parent_ino(sfp, args->inumber);
    }
    /*
     * Normal entry, look for the name.
     */
    else {
        for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp);
                i < sfp->count;
                i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep)) {
            if (xfs_da_compname(args, sfep->name, sfep->namelen) ==
                                XFS_CMP_EXACT) {
#if XFS_BIG_INUMS || defined(DEBUG)
                ino = xfs_dir2_sfe_get_ino(sfp, sfep);
                ASSERT(args->inumber != ino);
#endif
                xfs_dir2_sfe_put_ino(sfp, sfep, args->inumber);
                break;
            }
        }
        /*
         * Didn't find it.
         */
        if (i == sfp->count) {
            ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
#if XFS_BIG_INUMS
            if (i8elevated)
                xfs_dir2_sf_toino4(args);
#endif
            return XFS_ERROR(ENOENT);
        }
    }
#if XFS_BIG_INUMS
    /*
     * See if the old number was large, the new number is small.
     */
    if (ino > XFS_DIR2_MAX_SHORT_INUM &&
        args->inumber <= XFS_DIR2_MAX_SHORT_INUM) {
        /*
         * And the old count was one, so need to convert to small.
         */
        if (sfp->i8count == 1)
            xfs_dir2_sf_toino4(args);
        else
            sfp->i8count--;
    }
    /*
     * See if the old number was small, the new number is large.
     */
    if (ino <= XFS_DIR2_MAX_SHORT_INUM &&
        args->inumber > XFS_DIR2_MAX_SHORT_INUM) {
        /*
         * add to the i8count unless we just converted to 8-byte
         * inodes (which does an implied i8count = 1)
         */
        ASSERT(sfp->i8count != 0);
        if (!i8elevated)
            sfp->i8count++;
    }
#endif
    xfs_dir2_sf_check(args);
    xfs_trans_log_inode(args->trans, dp, XFS_ILOG_DDATA);
    return 0;
}

#if XFS_BIG_INUMS
/*
 * Convert from 8-byte inode numbers to 4-byte inode numbers.
 * The last 8-byte inode number is gone, but the count is still 1.
 */
static void
xfs_dir2_sf_toino4(
    xfs_da_args_t       *args)      /* operation arguments */
{
    char            *buf;       /* old dir's buffer */
    xfs_inode_t     *dp;        /* incore directory inode */
    int         i;      /* entry index */
    int         newsize;    /* new inode size */
    xfs_dir2_sf_entry_t *oldsfep;   /* old sf entry */
    xfs_dir2_sf_hdr_t   *oldsfp;    /* old sf directory */
    int         oldsize;    /* old inode size */
    xfs_dir2_sf_entry_t *sfep;      /* new sf entry */
    xfs_dir2_sf_hdr_t   *sfp;       /* new sf directory */

    trace_xfs_dir2_sf_toino4(args);

    dp = args->dp;

    /*
     * Copy the old directory to the buffer.
     * Then nuke it from the inode, and add the new buffer to the inode.
     * Don't want xfs_idata_realloc copying the data here.
     */
    oldsize = dp->i_df.if_bytes;
    buf = kmem_alloc(oldsize, KM_SLEEP);
    oldsfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    ASSERT(oldsfp->i8count == 1);
    memcpy(buf, oldsfp, oldsize);
    /*
     * Compute the new inode size.
     */
    newsize =
        oldsize -
        (oldsfp->count + 1) *
        ((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t));
    xfs_idata_realloc(dp, -oldsize, XFS_DATA_FORK);
    xfs_idata_realloc(dp, newsize, XFS_DATA_FORK);
    /*
     * Reset our pointers, the data has moved.
     */
    oldsfp = (xfs_dir2_sf_hdr_t *)buf;
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    /*
     * Fill in the new header.
     */
    sfp->count = oldsfp->count;
    sfp->i8count = 0;
    xfs_dir2_sf_put_parent_ino(sfp, xfs_dir2_sf_get_parent_ino(oldsfp));
    /*
     * Copy the entries field by field.
     */
    for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp),
            oldsfep = xfs_dir2_sf_firstentry(oldsfp);
         i < sfp->count;
         i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep),
          oldsfep = xfs_dir2_sf_nextentry(oldsfp, oldsfep)) {
        sfep->namelen = oldsfep->namelen;
        sfep->offset = oldsfep->offset;
        memcpy(sfep->name, oldsfep->name, sfep->namelen);
        xfs_dir2_sfe_put_ino(sfp, sfep,
            xfs_dir2_sfe_get_ino(oldsfp, oldsfep));
    }
    /*
     * Clean up the inode.
     */
    kmem_free(buf);
    dp->i_d.di_size = newsize;
    xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);
}

/*
 * Convert from 4-byte inode numbers to 8-byte inode numbers.
 * The new 8-byte inode number is not there yet, we leave with the
 * count 1 but no corresponding entry.
 */
static void
xfs_dir2_sf_toino8(
    xfs_da_args_t       *args)      /* operation arguments */
{
    char            *buf;       /* old dir's buffer */
    xfs_inode_t     *dp;        /* incore directory inode */
    int         i;      /* entry index */
    int         newsize;    /* new inode size */
    xfs_dir2_sf_entry_t *oldsfep;   /* old sf entry */
    xfs_dir2_sf_hdr_t   *oldsfp;    /* old sf directory */
    int         oldsize;    /* old inode size */
    xfs_dir2_sf_entry_t *sfep;      /* new sf entry */
    xfs_dir2_sf_hdr_t   *sfp;       /* new sf directory */

    trace_xfs_dir2_sf_toino8(args);

    dp = args->dp;

    /*
     * Copy the old directory to the buffer.
     * Then nuke it from the inode, and add the new buffer to the inode.
     * Don't want xfs_idata_realloc copying the data here.
     */
    oldsize = dp->i_df.if_bytes;
    buf = kmem_alloc(oldsize, KM_SLEEP);
    oldsfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    ASSERT(oldsfp->i8count == 0);
    memcpy(buf, oldsfp, oldsize);
    /*
     * Compute the new inode size.
     */
    newsize =
        oldsize +
        (oldsfp->count + 1) *
        ((uint)sizeof(xfs_dir2_ino8_t) - (uint)sizeof(xfs_dir2_ino4_t));
    xfs_idata_realloc(dp, -oldsize, XFS_DATA_FORK);
    xfs_idata_realloc(dp, newsize, XFS_DATA_FORK);
    /*
     * Reset our pointers, the data has moved.
     */
    oldsfp = (xfs_dir2_sf_hdr_t *)buf;
    sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
    /*
     * Fill in the new header.
     */
    sfp->count = oldsfp->count;
    sfp->i8count = 1;
    xfs_dir2_sf_put_parent_ino(sfp, xfs_dir2_sf_get_parent_ino(oldsfp));
    /*
     * Copy the entries field by field.
     */
    for (i = 0, sfep = xfs_dir2_sf_firstentry(sfp),
            oldsfep = xfs_dir2_sf_firstentry(oldsfp);
         i < sfp->count;
         i++, sfep = xfs_dir2_sf_nextentry(sfp, sfep),
          oldsfep = xfs_dir2_sf_nextentry(oldsfp, oldsfep)) {
        sfep->namelen = oldsfep->namelen;
        sfep->offset = oldsfep->offset;
        memcpy(sfep->name, oldsfep->name, sfep->namelen);
        xfs_dir2_sfe_put_ino(sfp, sfep,
            xfs_dir2_sfe_get_ino(oldsfp, oldsfep));
    }
    /*
     * Clean up the inode.
     */
    kmem_free(buf);
    dp->i_d.di_size = newsize;
    xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);
}
#endif  /* XFS_BIG_INUMS */