Linux-2.6.12-rc2

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / xfs / xfs_dir_leaf.c

/*
 * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 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.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

/*
 * xfs_dir_leaf.c
 *
 * GROT: figure out how to recover gracefully when bmap returns ENOSPC.
 */

#include "xfs.h"

#include "xfs_macros.h"
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_alloc_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_alloc.h"
#include "xfs_btree.h"
#include "xfs_attr_sf.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode_item.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_da_btree.h"
#include "xfs_dir_leaf.h"
#include "xfs_error.h"

/*
 * xfs_dir_leaf.c
 *
 * Routines to implement leaf blocks of directories as Btrees of hashed names.
 */

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

/*
 * Routines used for growing the Btree.
 */
STATIC void xfs_dir_leaf_add_work(xfs_dabuf_t *leaf_buffer, xfs_da_args_t *args,
                                              int insertion_index,
                                              int freemap_index);
STATIC int xfs_dir_leaf_compact(xfs_trans_t *trans, xfs_dabuf_t *leaf_buffer,
                                            int musthave, int justcheck);
STATIC void xfs_dir_leaf_rebalance(xfs_da_state_t *state,
                                                  xfs_da_state_blk_t *blk1,
                                                  xfs_da_state_blk_t *blk2);
STATIC int xfs_dir_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_namebytes_in_blk1);

/*
 * Utility routines.
 */
STATIC void xfs_dir_leaf_moveents(xfs_dir_leafblock_t *src_leaf,
                                              int src_start,
                                              xfs_dir_leafblock_t *dst_leaf,
                                              int dst_start, int move_count,
                                              xfs_mount_t *mp);


/*========================================================================
 * External routines when dirsize < XFS_IFORK_DSIZE(dp).
 *========================================================================*/


/*
 * Validate a given inode number.
 */
int
xfs_dir_ino_validate(xfs_mount_t *mp, xfs_ino_t ino)
{
        xfs_agblock_t   agblkno;
        xfs_agino_t     agino;
        xfs_agnumber_t  agno;
        int             ino_ok;
        int             ioff;

        agno = XFS_INO_TO_AGNO(mp, ino);
        agblkno = XFS_INO_TO_AGBNO(mp, ino);
        ioff = XFS_INO_TO_OFFSET(mp, ino);
        agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
        ino_ok =
                agno < mp->m_sb.sb_agcount &&
                agblkno < mp->m_sb.sb_agblocks &&
                agblkno != 0 &&
                ioff < (1 << mp->m_sb.sb_inopblog) &&
                XFS_AGINO_TO_INO(mp, agno, agino) == ino;
        if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE,
                        XFS_RANDOM_DIR_INO_VALIDATE))) {
                xfs_fs_cmn_err(CE_WARN, mp, "Invalid inode number 0x%Lx",
                                (unsigned long long) ino);
                XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
                return XFS_ERROR(EFSCORRUPTED);
        }
        return 0;
}

/*
 * Create the initial contents of a shortform directory.
 */
int
xfs_dir_shortform_create(xfs_da_args_t *args, xfs_ino_t parent)
{
        xfs_dir_sf_hdr_t *hdr;
        xfs_inode_t *dp;

        dp = args->dp;
        ASSERT(dp != NULL);
        ASSERT(dp->i_d.di_size == 0);
        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);
        xfs_idata_realloc(dp, sizeof(*hdr), XFS_DATA_FORK);
        hdr = (xfs_dir_sf_hdr_t *)dp->i_df.if_u1.if_data;
        XFS_DIR_SF_PUT_DIRINO(&parent, &hdr->parent);

        hdr->count = 0;
        dp->i_d.di_size = sizeof(*hdr);
        xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);
        return(0);
}

/*
 * Add a name to the shortform directory structure.
 * Overflow from the inode has already been checked for.
 */
int
xfs_dir_shortform_addname(xfs_da_args_t *args)
{
        xfs_dir_shortform_t *sf;
        xfs_dir_sf_entry_t *sfe;
        int i, offset, size;
        xfs_inode_t *dp;

        dp = args->dp;
        ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
        /*
         * Catch the case where the conversion from shortform to leaf
         * failed part way through.
         */
        if (dp->i_d.di_size < sizeof(xfs_dir_sf_hdr_t)) {
                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);
        sf = (xfs_dir_shortform_t *)dp->i_df.if_u1.if_data;
        sfe = &sf->list[0];
        for (i = INT_GET(sf->hdr.count, ARCH_CONVERT)-1; i >= 0; i--) {
                if (sfe->namelen == args->namelen &&
                    args->name[0] == sfe->name[0] &&
                    memcmp(args->name, sfe->name, args->namelen) == 0)
                        return(XFS_ERROR(EEXIST));
                sfe = XFS_DIR_SF_NEXTENTRY(sfe);
        }

        offset = (int)((char *)sfe - (char *)sf);
        size = XFS_DIR_SF_ENTSIZE_BYNAME(args->namelen);
        xfs_idata_realloc(dp, size, XFS_DATA_FORK);
        sf = (xfs_dir_shortform_t *)dp->i_df.if_u1.if_data;
        sfe = (xfs_dir_sf_entry_t *)((char *)sf + offset);

        XFS_DIR_SF_PUT_DIRINO(&args->inumber, &sfe->inumber);
        sfe->namelen = args->namelen;
        memcpy(sfe->name, args->name, sfe->namelen);
        INT_MOD(sf->hdr.count, ARCH_CONVERT, +1);

        dp->i_d.di_size += size;
        xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);

        return(0);
}

/*
 * Remove a name from the shortform directory structure.
 */
int
xfs_dir_shortform_removename(xfs_da_args_t *args)
{
        xfs_dir_shortform_t *sf;
        xfs_dir_sf_entry_t *sfe;
        int base, size = 0, i;
        xfs_inode_t *dp;

        dp = args->dp;
        ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
        /*
         * Catch the case where the conversion from shortform to leaf
         * failed part way through.
         */
        if (dp->i_d.di_size < sizeof(xfs_dir_sf_hdr_t)) {
                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);
        base = sizeof(xfs_dir_sf_hdr_t);
        sf = (xfs_dir_shortform_t *)dp->i_df.if_u1.if_data;
        sfe = &sf->list[0];
        for (i = INT_GET(sf->hdr.count, ARCH_CONVERT)-1; i >= 0; i--) {
                size = XFS_DIR_SF_ENTSIZE_BYENTRY(sfe);
                if (sfe->namelen == args->namelen &&
                    sfe->name[0] == args->name[0] &&
                    memcmp(sfe->name, args->name, args->namelen) == 0)
                        break;
                base += size;
                sfe = XFS_DIR_SF_NEXTENTRY(sfe);
        }
        if (i < 0) {
                ASSERT(args->oknoent);
                return(XFS_ERROR(ENOENT));
        }

        if ((base + size) != dp->i_d.di_size) {
                memmove(&((char *)sf)[base], &((char *)sf)[base+size],
                                              dp->i_d.di_size - (base+size));
        }
        INT_MOD(sf->hdr.count, ARCH_CONVERT, -1);

        xfs_idata_realloc(dp, -size, XFS_DATA_FORK);
        dp->i_d.di_size -= size;
        xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE | XFS_ILOG_DDATA);

        return(0);
}

/*
 * Look up a name in a shortform directory structure.
 */
int
xfs_dir_shortform_lookup(xfs_da_args_t *args)
{
        xfs_dir_shortform_t *sf;
        xfs_dir_sf_entry_t *sfe;
        int i;
        xfs_inode_t *dp;

        dp = args->dp;
        ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
        /*
         * Catch the case where the conversion from shortform to leaf
         * failed part way through.
         */
        if (dp->i_d.di_size < sizeof(xfs_dir_sf_hdr_t)) {
                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);
        sf = (xfs_dir_shortform_t *)dp->i_df.if_u1.if_data;
        if (args->namelen == 2 &&
            args->name[0] == '.' && args->name[1] == '.') {
                XFS_DIR_SF_GET_DIRINO(&sf->hdr.parent, &args->inumber);
                return(XFS_ERROR(EEXIST));
        }
        if (args->namelen == 1 && args->name[0] == '.') {
                args->inumber = dp->i_ino;
                return(XFS_ERROR(EEXIST));
        }
        sfe = &sf->list[0];
        for (i = INT_GET(sf->hdr.count, ARCH_CONVERT)-1; i >= 0; i--) {
                if (sfe->namelen == args->namelen &&
                    sfe->name[0] == args->name[0] &&
                    memcmp(args->name, sfe->name, args->namelen) == 0) {
                        XFS_DIR_SF_GET_DIRINO(&sfe->inumber, &args->inumber);
                        return(XFS_ERROR(EEXIST));
                }
                sfe = XFS_DIR_SF_NEXTENTRY(sfe);
        }
        ASSERT(args->oknoent);
        return(XFS_ERROR(ENOENT));
}

/*
 * Convert from using the shortform to the leaf.
 */
int
xfs_dir_shortform_to_leaf(xfs_da_args_t *iargs)
{
        xfs_inode_t *dp;
        xfs_dir_shortform_t *sf;
        xfs_dir_sf_entry_t *sfe;
        xfs_da_args_t args;
        xfs_ino_t inumber;
        char *tmpbuffer;
        int retval, i, size;
        xfs_dablk_t blkno;
        xfs_dabuf_t *bp;

        dp = iargs->dp;
        /*
         * Catch the case where the conversion from shortform to leaf
         * failed part way through.
         */
        if (dp->i_d.di_size < sizeof(xfs_dir_sf_hdr_t)) {
                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);
        size = dp->i_df.if_bytes;
        tmpbuffer = kmem_alloc(size, KM_SLEEP);
        ASSERT(tmpbuffer != NULL);

        memcpy(tmpbuffer, dp->i_df.if_u1.if_data, size);

        sf = (xfs_dir_shortform_t *)tmpbuffer;
        XFS_DIR_SF_GET_DIRINO(&sf->hdr.parent, &inumber);

        xfs_idata_realloc(dp, -size, XFS_DATA_FORK);
        dp->i_d.di_size = 0;
        xfs_trans_log_inode(iargs->trans, dp, XFS_ILOG_CORE);
        retval = xfs_da_grow_inode(iargs, &blkno);
        if (retval)
                goto out;

        ASSERT(blkno == 0);
        retval = xfs_dir_leaf_create(iargs, blkno, &bp);
        if (retval)
                goto out;
        xfs_da_buf_done(bp);

        args.name = ".";
        args.namelen = 1;
        args.hashval = xfs_dir_hash_dot;
        args.inumber = dp->i_ino;
        args.dp = dp;
        args.firstblock = iargs->firstblock;
        args.flist = iargs->flist;
        args.total = iargs->total;
        args.whichfork = XFS_DATA_FORK;
        args.trans = iargs->trans;
        args.justcheck = 0;
        args.addname = args.oknoent = 1;
        retval = xfs_dir_leaf_addname(&args);
        if (retval)
                goto out;

        args.name = "..";
        args.namelen = 2;
        args.hashval = xfs_dir_hash_dotdot;
        args.inumber = inumber;
        retval = xfs_dir_leaf_addname(&args);
        if (retval)
                goto out;

        sfe = &sf->list[0];
        for (i = 0; i < INT_GET(sf->hdr.count, ARCH_CONVERT); i++) {
                args.name = (char *)(sfe->name);
                args.namelen = sfe->namelen;
                args.hashval = xfs_da_hashname((char *)(sfe->name),
                                               sfe->namelen);
                XFS_DIR_SF_GET_DIRINO(&sfe->inumber, &args.inumber);
                retval = xfs_dir_leaf_addname(&args);
                if (retval)
                        goto out;
                sfe = XFS_DIR_SF_NEXTENTRY(sfe);
        }
        retval = 0;

out:
        kmem_free(tmpbuffer, size);
        return(retval);
}

STATIC int
xfs_dir_shortform_compare(const void *a, const void *b)
{
        xfs_dir_sf_sort_t *sa, *sb;

        sa = (xfs_dir_sf_sort_t *)a;
        sb = (xfs_dir_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;
}

/*
 * Copy out directory entries for getdents(), for shortform directories.
 */
/*ARGSUSED*/
int
xfs_dir_shortform_getdents(xfs_inode_t *dp, uio_t *uio, int *eofp,
                                       xfs_dirent_t *dbp, xfs_dir_put_t put)
{
        xfs_dir_shortform_t *sf;
        xfs_dir_sf_entry_t *sfe;
        int retval, i, sbsize, nsbuf, lastresid=0, want_entno;
        xfs_mount_t *mp;
        xfs_dahash_t cookhash, hash;
        xfs_dir_put_args_t p;
        xfs_dir_sf_sort_t *sbuf, *sbp;

        mp = dp->i_mount;
        sf = (xfs_dir_shortform_t *)dp->i_df.if_u1.if_data;
        cookhash = XFS_DA_COOKIE_HASH(mp, uio->uio_offset);
        want_entno = XFS_DA_COOKIE_ENTRY(mp, uio->uio_offset);
        nsbuf = INT_GET(sf->hdr.count, ARCH_CONVERT) + 2;
        sbsize = (nsbuf + 1) * sizeof(*sbuf);
        sbp = sbuf = kmem_alloc(sbsize, KM_SLEEP);

        xfs_dir_trace_g_du("sf: start", dp, uio);

        /*
         * Collect all the entries into the buffer.
         * Entry 0 is .
         */
        sbp->entno = 0;
        sbp->seqno = 0;
        sbp->hash = xfs_dir_hash_dot;
        sbp->ino = dp->i_ino;
        sbp->name = ".";
        sbp->namelen = 1;
        sbp++;

        /*
         * Entry 1 is ..
         */
        sbp->entno = 1;
        sbp->seqno = 0;
        sbp->hash = xfs_dir_hash_dotdot;
        sbp->ino = XFS_GET_DIR_INO8(sf->hdr.parent);
        sbp->name = "..";
        sbp->namelen = 2;
        sbp++;

        /*
         * Scan the directory data for the rest of the entries.
         */
        for (i = 0, sfe = &sf->list[0];
                        i < INT_GET(sf->hdr.count, ARCH_CONVERT); i++) {

                if (unlikely(
                    ((char *)sfe < (char *)sf) ||
                    ((char *)sfe >= ((char *)sf + dp->i_df.if_bytes)))) {
                        xfs_dir_trace_g_du("sf: corrupted", dp, uio);
                        XFS_CORRUPTION_ERROR("xfs_dir_shortform_getdents",
                                             XFS_ERRLEVEL_LOW, mp, sfe);
                        kmem_free(sbuf, sbsize);
                        return XFS_ERROR(EFSCORRUPTED);
                }

                sbp->entno = i + 2;
                sbp->seqno = 0;
                sbp->hash = xfs_da_hashname((char *)sfe->name, sfe->namelen);
                sbp->ino = XFS_GET_DIR_INO8(sfe->inumber);
                sbp->name = (char *)sfe->name;
                sbp->namelen = sfe->namelen;
                sfe = XFS_DIR_SF_NEXTENTRY(sfe);
                sbp++;
        }

        /*
         * Sort the entries on hash then entno.
         */
        qsort(sbuf, nsbuf, sizeof(*sbuf), xfs_dir_shortform_compare);
        /*
         * Stuff in last entry.
         */
        sbp->entno = nsbuf;
        sbp->hash = XFS_DA_MAXHASH;
        sbp->seqno = 0;
        /*
         * Figure out the sequence numbers in case there's a hash duplicate.
         */
        for (hash = sbuf->hash, sbp = sbuf + 1;
                                sbp < &sbuf[nsbuf + 1]; sbp++) {
                if (sbp->hash == hash)
                        sbp->seqno = sbp[-1].seqno + 1;
                else
                        hash = sbp->hash;
        }

        /*
         * Set up put routine.
         */
        p.dbp = dbp;
        p.put = put;
        p.uio = uio;

        /*
         * Find our place.
         */
        for (sbp = sbuf; sbp < &sbuf[nsbuf + 1]; sbp++) {
                if (sbp->hash > cookhash ||
                    (sbp->hash == cookhash && sbp->seqno >= want_entno))
                        break;
        }

        /*
         * Did we fail to find anything?  We stop at the last entry,
         * the one we put maxhash into.
         */
        if (sbp == &sbuf[nsbuf]) {
                kmem_free(sbuf, sbsize);
                xfs_dir_trace_g_du("sf: hash beyond end", dp, uio);
                uio->uio_offset = XFS_DA_MAKE_COOKIE(mp, 0, 0, XFS_DA_MAXHASH);
                *eofp = 1;
                return 0;
        }

        /*
         * Loop putting entries into the user buffer.
         */
        while (sbp < &sbuf[nsbuf]) {
                /*
                 * Save the first resid in a run of equal-hashval entries
                 * so that we can back them out if they don't all fit.
                 */
                if (sbp->seqno == 0 || sbp == sbuf)
                        lastresid = uio->uio_resid;
                XFS_PUT_COOKIE(p.cook, mp, 0, sbp[1].seqno, sbp[1].hash);
                p.ino = sbp->ino;
#if XFS_BIG_INUMS
                p.ino += mp->m_inoadd;
#endif
                p.name = sbp->name;
                p.namelen = sbp->namelen;
                retval = p.put(&p);
                if (!p.done) {
                        uio->uio_offset =
                                XFS_DA_MAKE_COOKIE(mp, 0, 0, sbp->hash);
                        kmem_free(sbuf, sbsize);
                        uio->uio_resid = lastresid;
                        xfs_dir_trace_g_du("sf: E-O-B", dp, uio);
                        return retval;
                }
                sbp++;
        }
        kmem_free(sbuf, sbsize);
        uio->uio_offset = p.cook.o;
        *eofp = 1;
        xfs_dir_trace_g_du("sf: E-O-F", dp, uio);
        return 0;
}

/*
 * Look up a name in a shortform directory structure, replace the inode number.
 */
int
xfs_dir_shortform_replace(xfs_da_args_t *args)
{
        xfs_dir_shortform_t *sf;
        xfs_dir_sf_entry_t *sfe;
        xfs_inode_t *dp;
        int i;

        dp = args->dp;
        ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
        /*
         * Catch the case where the conversion from shortform to leaf
         * failed part way through.
         */
        if (dp->i_d.di_size < sizeof(xfs_dir_sf_hdr_t)) {
                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);
        sf = (xfs_dir_shortform_t *)dp->i_df.if_u1.if_data;
        if (args->namelen == 2 &&
            args->name[0] == '.' && args->name[1] == '.') {
                /* XXX - replace assert? */
                XFS_DIR_SF_PUT_DIRINO(&args->inumber, &sf->hdr.parent);
                xfs_trans_log_inode(args->trans, dp, XFS_ILOG_DDATA);
                return(0);
        }
        ASSERT(args->namelen != 1 || args->name[0] != '.');
        sfe = &sf->list[0];
        for (i = INT_GET(sf->hdr.count, ARCH_CONVERT)-1; i >= 0; i--) {
                if (sfe->namelen == args->namelen &&
                    sfe->name[0] == args->name[0] &&
                    memcmp(args->name, sfe->name, args->namelen) == 0) {
                        ASSERT(memcmp((char *)&args->inumber,
                                (char *)&sfe->inumber, sizeof(xfs_ino_t)));
                        XFS_DIR_SF_PUT_DIRINO(&args->inumber, &sfe->inumber);
                        xfs_trans_log_inode(args->trans, dp, XFS_ILOG_DDATA);
                        return(0);
                }
                sfe = XFS_DIR_SF_NEXTENTRY(sfe);
        }
        ASSERT(args->oknoent);
        return(XFS_ERROR(ENOENT));
}

/*
 * Convert a leaf directory to shortform structure
 */
int
xfs_dir_leaf_to_shortform(xfs_da_args_t *iargs)
{
        xfs_dir_leafblock_t *leaf;
        xfs_dir_leaf_hdr_t *hdr;
        xfs_dir_leaf_entry_t *entry;
        xfs_dir_leaf_name_t *namest;
        xfs_da_args_t args;
        xfs_inode_t *dp;
        xfs_ino_t parent;
        char *tmpbuffer;
        int retval, i;
        xfs_dabuf_t *bp;

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

        retval = xfs_da_read_buf(iargs->trans, iargs->dp, 0, -1, &bp,
                                               XFS_DATA_FORK);
        if (retval)
                goto out;
        ASSERT(bp != NULL);
        memcpy(tmpbuffer, bp->data, XFS_LBSIZE(dp->i_mount));
        leaf = (xfs_dir_leafblock_t *)tmpbuffer;
        ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        memset(bp->data, 0, XFS_LBSIZE(dp->i_mount));

        /*
         * Find and special case the parent inode number
         */
        hdr = &leaf->hdr;
        entry = &leaf->entries[0];
        for (i = INT_GET(hdr->count, ARCH_CONVERT)-1; i >= 0; entry++, i--) {
                namest = XFS_DIR_LEAF_NAMESTRUCT(leaf, INT_GET(entry->nameidx, ARCH_CONVERT));
                if ((entry->namelen == 2) &&
                    (namest->name[0] == '.') &&
                    (namest->name[1] == '.')) {
                        XFS_DIR_SF_GET_DIRINO(&namest->inumber, &parent);
                        entry->nameidx = 0;
                } else if ((entry->namelen == 1) && (namest->name[0] == '.')) {
                        entry->nameidx = 0;
                }
        }
        retval = xfs_da_shrink_inode(iargs, 0, bp);
        if (retval)
                goto out;
        retval = xfs_dir_shortform_create(iargs, parent);
        if (retval)
                goto out;

        /*
         * Copy the rest of the filenames
         */
        entry = &leaf->entries[0];
        args.dp = dp;
        args.firstblock = iargs->firstblock;
        args.flist = iargs->flist;
        args.total = iargs->total;
        args.whichfork = XFS_DATA_FORK;
        args.trans = iargs->trans;
        args.justcheck = 0;
        args.addname = args.oknoent = 1;
        for (i = 0; i < INT_GET(hdr->count, ARCH_CONVERT); entry++, i++) {
                if (!entry->nameidx)
                        continue;
                namest = XFS_DIR_LEAF_NAMESTRUCT(leaf, INT_GET(entry->nameidx, ARCH_CONVERT));
                args.name = (char *)(namest->name);
                args.namelen = entry->namelen;
                args.hashval = INT_GET(entry->hashval, ARCH_CONVERT);
                XFS_DIR_SF_GET_DIRINO(&namest->inumber, &args.inumber);
                xfs_dir_shortform_addname(&args);
        }

out:
        kmem_free(tmpbuffer, XFS_LBSIZE(dp->i_mount));
        return(retval);
}

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

        dp = args->dp;
        retval = xfs_da_grow_inode(args, &blkno);
        ASSERT(blkno == 1);
        if (retval)
                return(retval);
        retval = xfs_da_read_buf(args->trans, args->dp, 0, -1, &bp1,
                                              XFS_DATA_FORK);
        if (retval)
                return(retval);
        ASSERT(bp1 != NULL);
        retval = xfs_da_get_buf(args->trans, args->dp, 1, -1, &bp2,
                                             XFS_DATA_FORK);
        if (retval) {
                xfs_da_buf_done(bp1);
                return(retval);
        }
        ASSERT(bp2 != NULL);
        memcpy(bp2->data, bp1->data, XFS_LBSIZE(dp->i_mount));
        xfs_da_buf_done(bp1);
        xfs_da_log_buf(args->trans, bp2, 0, XFS_LBSIZE(dp->i_mount) - 1);

        /*
         * Set up the new root node.
         */
        retval = xfs_da_node_create(args, 0, 1, &bp1, XFS_DATA_FORK);
        if (retval) {
                xfs_da_buf_done(bp2);
                return(retval);
        }
        node = bp1->data;
        leaf = bp2->data;
        ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        INT_SET(node->btree[0].hashval, ARCH_CONVERT, INT_GET(leaf->entries[ INT_GET(leaf->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT));
        xfs_da_buf_done(bp2);
        INT_SET(node->btree[0].before, ARCH_CONVERT, blkno);
        INT_SET(node->hdr.count, ARCH_CONVERT, 1);
        xfs_da_log_buf(args->trans, bp1,
                XFS_DA_LOGRANGE(node, &node->btree[0], sizeof(node->btree[0])));
        xfs_da_buf_done(bp1);

        return(retval);
}


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

/*
 * Create the initial contents of a leaf directory
 * or a leaf in a node directory.
 */
int
xfs_dir_leaf_create(xfs_da_args_t *args, xfs_dablk_t blkno, xfs_dabuf_t **bpp)
{
        xfs_dir_leafblock_t *leaf;
        xfs_dir_leaf_hdr_t *hdr;
        xfs_inode_t *dp;
        xfs_dabuf_t *bp;
        int retval;

        dp = args->dp;
        ASSERT(dp != NULL);
        retval = xfs_da_get_buf(args->trans, dp, blkno, -1, &bp, XFS_DATA_FORK);
        if (retval)
                return(retval);
        ASSERT(bp != NULL);
        leaf = bp->data;
        memset((char *)leaf, 0, XFS_LBSIZE(dp->i_mount));
        hdr = &leaf->hdr;
        INT_SET(hdr->info.magic, ARCH_CONVERT, XFS_DIR_LEAF_MAGIC);
        INT_SET(hdr->firstused, ARCH_CONVERT, XFS_LBSIZE(dp->i_mount));
        if (!hdr->firstused)
                INT_SET(hdr->firstused, ARCH_CONVERT, XFS_LBSIZE(dp->i_mount) - 1);
        INT_SET(hdr->freemap[0].base, ARCH_CONVERT, sizeof(xfs_dir_leaf_hdr_t));
        INT_SET(hdr->freemap[0].size, ARCH_CONVERT, INT_GET(hdr->firstused, ARCH_CONVERT) - INT_GET(hdr->freemap[0].base, ARCH_CONVERT));

        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_dir_leaf_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
                                  xfs_da_state_blk_t *newblk)
{
        xfs_dablk_t blkno;
        xfs_da_args_t *args;
        int error;

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

        /*
         * Rebalance the entries across the two leaves.
         */
        xfs_dir_leaf_rebalance(state, oldblk, newblk);
        error = xfs_da_blk_link(state, oldblk, newblk);
        if (error)
                return(error);

        /*
         * Insert the new entry in the correct block.
         */
        if (state->inleaf) {
                error = xfs_dir_leaf_add(oldblk->bp, args, oldblk->index);
        } else {
                error = xfs_dir_leaf_add(newblk->bp, args, newblk->index);
        }

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

/*
 * Add a name to the leaf directory structure.
 *
 * Must take into account fragmented leaves and leaves where spacemap has
 * lost some freespace information (ie: holes).
 */
int
xfs_dir_leaf_add(xfs_dabuf_t *bp, xfs_da_args_t *args, int index)
{
        xfs_dir_leafblock_t *leaf;
        xfs_dir_leaf_hdr_t *hdr;
        xfs_dir_leaf_map_t *map;
        int tablesize, entsize, sum, i, tmp, error;

        leaf = bp->data;
        ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        ASSERT((index >= 0) && (index <= INT_GET(leaf->hdr.count, ARCH_CONVERT)));
        hdr = &leaf->hdr;
        entsize = XFS_DIR_LEAF_ENTSIZE_BYNAME(args->namelen);

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

        /*
         * 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.
         * Pass the justcheck flag so the checking pass can return
         * an error, without changing anything, if it won't fit.
         */
        error = xfs_dir_leaf_compact(args->trans, bp,
                        args->total == 0 ?
                                entsize +
                                (uint)sizeof(xfs_dir_leaf_entry_t) : 0,
                        args->justcheck);
        if (error)
                return(error);
        /*
         * After compaction, the block is guaranteed to have only one
         * free region, in freemap[0].  If it is not big enough, give up.
         */
        if (INT_GET(hdr->freemap[0].size, ARCH_CONVERT) <
            (entsize + (uint)sizeof(xfs_dir_leaf_entry_t)))
                return(XFS_ERROR(ENOSPC));

        if (!args->justcheck)
                xfs_dir_leaf_add_work(bp, args, index, 0);
        return(0);
}

/*
 * Add a name to a leaf directory structure.
 */
STATIC void
xfs_dir_leaf_add_work(xfs_dabuf_t *bp, xfs_da_args_t *args, int index,
                      int mapindex)
{
        xfs_dir_leafblock_t *leaf;
        xfs_dir_leaf_hdr_t *hdr;
        xfs_dir_leaf_entry_t *entry;
        xfs_dir_leaf_name_t *namest;
        xfs_dir_leaf_map_t *map;
        /* REFERENCED */
        xfs_mount_t *mp;
        int tmp, i;

        leaf = bp->data;
        ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        hdr = &leaf->hdr;
        ASSERT((mapindex >= 0) && (mapindex < XFS_DIR_LEAF_MAPSIZE));
        ASSERT((index >= 0) && (index <= INT_GET(hdr->count, ARCH_CONVERT)));

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

        /*
         * Allocate space for the new string (at the end of the run).
         */
        map = &hdr->freemap[mapindex];
        mp = args->trans->t_mountp;
        ASSERT(INT_GET(map->base, ARCH_CONVERT) < XFS_LBSIZE(mp));
        ASSERT(INT_GET(map->size, ARCH_CONVERT) >= XFS_DIR_LEAF_ENTSIZE_BYNAME(args->namelen));
        ASSERT(INT_GET(map->size, ARCH_CONVERT) < XFS_LBSIZE(mp));
        INT_MOD(map->size, ARCH_CONVERT, -(XFS_DIR_LEAF_ENTSIZE_BYNAME(args->namelen)));
        INT_SET(entry->nameidx, ARCH_CONVERT, INT_GET(map->base, ARCH_CONVERT) + INT_GET(map->size, ARCH_CONVERT));
        INT_SET(entry->hashval, ARCH_CONVERT, args->hashval);
        entry->namelen = args->namelen;
        xfs_da_log_buf(args->trans, bp,
            XFS_DA_LOGRANGE(leaf, entry, sizeof(*entry)));

        /*
         * Copy the string and inode number into the new space.
         */
        namest = XFS_DIR_LEAF_NAMESTRUCT(leaf, INT_GET(entry->nameidx, ARCH_CONVERT));
        XFS_DIR_SF_PUT_DIRINO(&args->inumber, &namest->inumber);
        memcpy(namest->name, args->name, args->namelen);
        xfs_da_log_buf(args->trans, bp,
            XFS_DA_LOGRANGE(leaf, namest, XFS_DIR_LEAF_ENTSIZE_BYENTRY(entry)));

        /*
         * Update the control info for this leaf node
         */
        if (INT_GET(entry->nameidx, ARCH_CONVERT) < INT_GET(hdr->firstused, ARCH_CONVERT))
                INT_COPY(hdr->firstused, entry->nameidx, ARCH_CONVERT);
        ASSERT(INT_GET(hdr->firstused, ARCH_CONVERT) >= ((INT_GET(hdr->count, ARCH_CONVERT)*sizeof(*entry))+sizeof(*hdr)));
        tmp = (INT_GET(hdr->count, ARCH_CONVERT)-1) * (uint)sizeof(xfs_dir_leaf_entry_t)
                        + (uint)sizeof(xfs_dir_leaf_hdr_t);
        map = &hdr->freemap[0];
        for (i = 0; i < XFS_DIR_LEAF_MAPSIZE; map++, i++) {
                if (INT_GET(map->base, ARCH_CONVERT) == tmp) {
                        INT_MOD(map->base, ARCH_CONVERT, (uint)sizeof(xfs_dir_leaf_entry_t));
                        INT_MOD(map->size, ARCH_CONVERT, -((uint)sizeof(xfs_dir_leaf_entry_t)));
                }
        }
        INT_MOD(hdr->namebytes, ARCH_CONVERT, args->namelen);
        xfs_da_log_buf(args->trans, bp,
                XFS_DA_LOGRANGE(leaf, hdr, sizeof(*hdr)));
}

/*
 * Garbage collect a leaf directory block by copying it to a new buffer.
 */
STATIC int
xfs_dir_leaf_compact(xfs_trans_t *trans, xfs_dabuf_t *bp, int musthave,
                     int justcheck)
{
        xfs_dir_leafblock_t *leaf_s, *leaf_d;
        xfs_dir_leaf_hdr_t *hdr_s, *hdr_d;
        xfs_mount_t *mp;
        char *tmpbuffer;
        char *tmpbuffer2=NULL;
        int rval;
        int lbsize;

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

        /*
         * Make a second copy in case xfs_dir_leaf_moveents()
         * below destroys the original.
         */
        if (musthave || justcheck) {
                tmpbuffer2 = kmem_alloc(lbsize, KM_SLEEP);
                memcpy(tmpbuffer2, bp->data, lbsize);
        }
        memset(bp->data, 0, lbsize);

        /*
         * Copy basic information
         */
        leaf_s = (xfs_dir_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 */
        INT_SET(hdr_d->firstused, ARCH_CONVERT, lbsize);
        if (!hdr_d->firstused)
                INT_SET(hdr_d->firstused, ARCH_CONVERT, lbsize - 1);
        hdr_d->namebytes = 0;
        hdr_d->count = 0;
        hdr_d->holes = 0;
        INT_SET(hdr_d->freemap[0].base, ARCH_CONVERT, sizeof(xfs_dir_leaf_hdr_t));
        INT_SET(hdr_d->freemap[0].size, ARCH_CONVERT, INT_GET(hdr_d->firstused, ARCH_CONVERT) - INT_GET(hdr_d->freemap[0].base, ARCH_CONVERT));

        /*
         * Copy all entry's in the same (sorted) order,
         * but allocate filenames packed and in sequence.
         * This changes the source (leaf_s) as well.
         */
        xfs_dir_leaf_moveents(leaf_s, 0, leaf_d, 0, (int)INT_GET(hdr_s->count, ARCH_CONVERT), mp);

        if (musthave && INT_GET(hdr_d->freemap[0].size, ARCH_CONVERT) < musthave)
                rval = XFS_ERROR(ENOSPC);
        else
                rval = 0;

        if (justcheck || rval == ENOSPC) {
                ASSERT(tmpbuffer2);
                memcpy(bp->data, tmpbuffer2, lbsize);
        } else {
                xfs_da_log_buf(trans, bp, 0, lbsize - 1);
        }

        kmem_free(tmpbuffer, lbsize);
        if (musthave || justcheck)
                kmem_free(tmpbuffer2, lbsize);
        return(rval);
}

/*
 * Redistribute the directory 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 old block.
 */
STATIC void
xfs_dir_leaf_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
                                      xfs_da_state_blk_t *blk2)
{
        xfs_da_state_blk_t *tmp_blk;
        xfs_dir_leafblock_t *leaf1, *leaf2;
        xfs_dir_leaf_hdr_t *hdr1, *hdr2;
        int count, totallen, max, space, swap;

        /*
         * Set up environment.
         */
        ASSERT(blk1->magic == XFS_DIR_LEAF_MAGIC);
        ASSERT(blk2->magic == XFS_DIR_LEAF_MAGIC);
        leaf1 = blk1->bp->data;
        leaf2 = blk2->bp->data;
        ASSERT(INT_GET(leaf1->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        ASSERT(INT_GET(leaf2->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);

        /*
         * Check ordering of blocks, reverse if it makes things simpler.
         */
        swap = 0;
        if (xfs_dir_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.
         */
        state->inleaf = xfs_dir_leaf_figure_balance(state, blk1, blk2,
                                                           &count, &totallen);
        if (swap)
                state->inleaf = !state->inleaf;

        /*
         * Move any entries required from leaf to leaf:
         */
        if (count < INT_GET(hdr1->count, ARCH_CONVERT)) {
                /*
                 * Figure the total bytes to be added to the destination leaf.
                 */
                count = INT_GET(hdr1->count, ARCH_CONVERT) - count;     /* number entries being moved */
                space  = INT_GET(hdr1->namebytes, ARCH_CONVERT) - totallen;
                space += count * ((uint)sizeof(xfs_dir_leaf_name_t)-1);
                space += count * (uint)sizeof(xfs_dir_leaf_entry_t);

                /*
                 * leaf2 is the destination, compact it if it looks tight.
                 */
                max  = INT_GET(hdr2->firstused, ARCH_CONVERT) - (uint)sizeof(xfs_dir_leaf_hdr_t);
                max -= INT_GET(hdr2->count, ARCH_CONVERT) * (uint)sizeof(xfs_dir_leaf_entry_t);
                if (space > max) {
                        xfs_dir_leaf_compact(state->args->trans, blk2->bp,
                                                                 0, 0);
                }

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

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

        } else if (count > INT_GET(hdr1->count, ARCH_CONVERT)) {
                /*
                 * Figure the total bytes to be added to the destination leaf.
                 */
                count -= INT_GET(hdr1->count, ARCH_CONVERT);            /* number entries being moved */
                space  = totallen - INT_GET(hdr1->namebytes, ARCH_CONVERT);
                space += count * ((uint)sizeof(xfs_dir_leaf_name_t)-1);
                space += count * (uint)sizeof(xfs_dir_leaf_entry_t);

                /*
                 * leaf1 is the destination, compact it if it looks tight.
                 */
                max  = INT_GET(hdr1->firstused, ARCH_CONVERT) - (uint)sizeof(xfs_dir_leaf_hdr_t);
                max -= INT_GET(hdr1->count, ARCH_CONVERT) * (uint)sizeof(xfs_dir_leaf_entry_t);
                if (space > max) {
                        xfs_dir_leaf_compact(state->args->trans, blk1->bp,
                                                                 0, 0);
                }

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

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

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

        /*
         * Adjust the expected index for insertion.
         * GROT: this doesn't work unless blk2 was originally empty.
         */
        if (!state->inleaf) {
                blk2->index = blk1->index - INT_GET(leaf1->hdr.count, ARCH_CONVERT);
        }
}

/*
 * 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_dir_leaf_figure_balance(xfs_da_state_t *state,
                                           xfs_da_state_blk_t *blk1,
                                           xfs_da_state_blk_t *blk2,
                                           int *countarg, int *namebytesarg)
{
        xfs_dir_leafblock_t *leaf1, *leaf2;
        xfs_dir_leaf_hdr_t *hdr1, *hdr2;
        xfs_dir_leaf_entry_t *entry;
        int count, max, 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 = INT_GET(hdr1->count, ARCH_CONVERT) + INT_GET(hdr2->count, ARCH_CONVERT);
        half  = (max+1) * (uint)(sizeof(*entry)+sizeof(xfs_dir_leaf_entry_t)-1);
        half += INT_GET(hdr1->namebytes, ARCH_CONVERT) + INT_GET(hdr2->namebytes, ARCH_CONVERT) + state->args->namelen;
        half /= 2;
        lastdelta = state->blocksize;
        entry = &leaf1->entries[0];
        for (count = 0; count < max; entry++, count++) {

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

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

                /*
                 * Figure out if next leaf entry would be too much.
                 */
                tmp = totallen + (uint)sizeof(*entry)
                                + XFS_DIR_LEAF_ENTSIZE_BYENTRY(entry);
                if (XFS_DIR_ABS(half - tmp) > lastdelta)
                        break;
                lastdelta = XFS_DIR_ABS(half - tmp);
                totallen = tmp;
#undef XFS_DIR_ABS
        }

        /*
         * Calculate the number of namebytes that will end up in lower block.
         * If new entry not in lower block, fix up the count.
         */
        totallen -=
                count * (uint)(sizeof(*entry)+sizeof(xfs_dir_leaf_entry_t)-1);
        if (foundit) {
                totallen -= (sizeof(*entry)+sizeof(xfs_dir_leaf_entry_t)-1) +
                            state->args->namelen;
        }

        *countarg = count;
        *namebytesarg = 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.
 */
int
xfs_dir_leaf_toosmall(xfs_da_state_t *state, int *action)
{
        xfs_dir_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(INT_GET(info->magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        leaf = (xfs_dir_leafblock_t *)info;
        count = INT_GET(leaf->hdr.count, ARCH_CONVERT);
        bytes = (uint)sizeof(xfs_dir_leaf_hdr_t) +
                count * (uint)sizeof(xfs_dir_leaf_entry_t) +
                count * ((uint)sizeof(xfs_dir_leaf_name_t)-1) +
                INT_GET(leaf->hdr.namebytes, ARCH_CONVERT);
        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 (aribtrarily)
         * 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;
                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 a directory over time.
         */
        forward = (INT_GET(info->forw, ARCH_CONVERT) < INT_GET(info->back, ARCH_CONVERT));      /* start with smaller blk num */
        for (i = 0; i < 2; forward = !forward, i++) {
                if (forward)
                        blkno = INT_GET(info->forw, ARCH_CONVERT);
                else
                        blkno = INT_GET(info->back, ARCH_CONVERT);
                if (blkno == 0)
                        continue;
                error = xfs_da_read_buf(state->args->trans, state->args->dp,
                                                            blkno, -1, &bp,
                                                            XFS_DATA_FORK);
                if (error)
                        return(error);
                ASSERT(bp != NULL);

                leaf = (xfs_dir_leafblock_t *)info;
                count  = INT_GET(leaf->hdr.count, ARCH_CONVERT);
                bytes  = state->blocksize - (state->blocksize>>2);
                bytes -= INT_GET(leaf->hdr.namebytes, ARCH_CONVERT);
                leaf = bp->data;
                ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
                count += INT_GET(leaf->hdr.count, ARCH_CONVERT);
                bytes -= INT_GET(leaf->hdr.namebytes, ARCH_CONVERT);
                bytes -= count * ((uint)sizeof(xfs_dir_leaf_name_t) - 1);
                bytes -= count * (uint)sizeof(xfs_dir_leaf_entry_t);
                bytes -= (uint)sizeof(xfs_dir_leaf_hdr_t);
                if (bytes >= 0)
                        break;  /* fits with at least 25% to spare */

                xfs_da_brelse(state->args->trans, bp);
        }
        if (i >= 2) {
                *action = 0;
                return(0);
        }
        xfs_da_buf_done(bp);

        /*
         * 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 directory 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_dir_leaf_remove(xfs_trans_t *trans, xfs_dabuf_t *bp, int index)
{
        xfs_dir_leafblock_t *leaf;
        xfs_dir_leaf_hdr_t *hdr;
        xfs_dir_leaf_map_t *map;
        xfs_dir_leaf_entry_t *entry;
        xfs_dir_leaf_name_t *namest;
        int before, after, smallest, entsize;
        int tablesize, tmp, i;
        xfs_mount_t *mp;

        leaf = bp->data;
        ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        hdr = &leaf->hdr;
        mp = trans->t_mountp;
        ASSERT((INT_GET(hdr->count, ARCH_CONVERT) > 0) && (INT_GET(hdr->count, ARCH_CONVERT) < (XFS_LBSIZE(mp)/8)));
        ASSERT((index >= 0) && (index < INT_GET(hdr->count, ARCH_CONVERT)));
        ASSERT(INT_GET(hdr->firstused, ARCH_CONVERT) >= ((INT_GET(hdr->count, ARCH_CONVERT)*sizeof(*entry))+sizeof(*hdr)));
        entry = &leaf->entries[index];
        ASSERT(INT_GET(entry->nameidx, ARCH_CONVERT) >= INT_GET(hdr->firstused, ARCH_CONVERT));
        ASSERT(INT_GET(entry->nameidx, ARCH_CONVERT) < 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 = INT_GET(hdr->count, ARCH_CONVERT) * (uint)sizeof(xfs_dir_leaf_entry_t)
                        + (uint)sizeof(xfs_dir_leaf_hdr_t);
        map = &hdr->freemap[0];
        tmp = INT_GET(map->size, ARCH_CONVERT);
        before = after = -1;
        smallest = XFS_DIR_LEAF_MAPSIZE - 1;
        entsize = XFS_DIR_LEAF_ENTSIZE_BYENTRY(entry);
        for (i = 0; i < XFS_DIR_LEAF_MAPSIZE; map++, i++) {
                ASSERT(INT_GET(map->base, ARCH_CONVERT) < XFS_LBSIZE(mp));
                ASSERT(INT_GET(map->size, ARCH_CONVERT) < XFS_LBSIZE(mp));
                if (INT_GET(map->base, ARCH_CONVERT) == tablesize) {
                        INT_MOD(map->base, ARCH_CONVERT, -((uint)sizeof(xfs_dir_leaf_entry_t)));
                        INT_MOD(map->size, ARCH_CONVERT, (uint)sizeof(xfs_dir_leaf_entry_t));
                }

                if ((INT_GET(map->base, ARCH_CONVERT) + INT_GET(map->size, ARCH_CONVERT)) == INT_GET(entry->nameidx, ARCH_CONVERT)) {
                        before = i;
                } else if (INT_GET(map->base, ARCH_CONVERT) == (INT_GET(entry->nameidx, ARCH_CONVERT) + entsize)) {
                        after = i;
                } else if (INT_GET(map->size, ARCH_CONVERT) < tmp) {
                        tmp = INT_GET(map->size, ARCH_CONVERT);
                        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];
                        INT_MOD(map->size, ARCH_CONVERT, entsize);
                        INT_MOD(map->size, ARCH_CONVERT, INT_GET(hdr->freemap[after].size, ARCH_CONVERT));
                        hdr->freemap[after].base = 0;
                        hdr->freemap[after].size = 0;
                } else if (before >= 0) {
                        map = &hdr->freemap[before];
                        INT_MOD(map->size, ARCH_CONVERT, entsize);
                } else {
                        map = &hdr->freemap[after];
                        INT_COPY(map->base, entry->nameidx, ARCH_CONVERT);
                        INT_MOD(map->size, ARCH_CONVERT, entsize);
                }
        } else {
                /*
                 * Replace smallest region (if it is smaller than free'd entry)
                 */
                map = &hdr->freemap[smallest];
                if (INT_GET(map->size, ARCH_CONVERT) < entsize) {
                        INT_COPY(map->base, entry->nameidx, ARCH_CONVERT);
                        INT_SET(map->size, ARCH_CONVERT, entsize);
                }
        }

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

        /*
         * Compress the remaining entries and zero out the removed stuff.
         */
        namest = XFS_DIR_LEAF_NAMESTRUCT(leaf, INT_GET(entry->nameidx, ARCH_CONVERT));
        memset((char *)namest, 0, entsize);
        xfs_da_log_buf(trans, bp, XFS_DA_LOGRANGE(leaf, namest, entsize));

        INT_MOD(hdr->namebytes, ARCH_CONVERT, -(entry->namelen));
        tmp = (INT_GET(hdr->count, ARCH_CONVERT) - index) * (uint)sizeof(xfs_dir_leaf_entry_t);
        memmove(entry, entry + 1, tmp);
        INT_MOD(hdr->count, ARCH_CONVERT, -1);
        xfs_da_log_buf(trans, bp,
            XFS_DA_LOGRANGE(leaf, entry, tmp + (uint)sizeof(*entry)));
        entry = &leaf->entries[INT_GET(hdr->count, ARCH_CONVERT)];
        memset((char *)entry, 0, sizeof(xfs_dir_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 = INT_GET(hdr->count, ARCH_CONVERT)-1; i >= 0; entry++, i--) {
                        ASSERT(INT_GET(entry->nameidx, ARCH_CONVERT) >= INT_GET(hdr->firstused, ARCH_CONVERT));
                        ASSERT(INT_GET(entry->nameidx, ARCH_CONVERT) < XFS_LBSIZE(mp));
                        if (INT_GET(entry->nameidx, ARCH_CONVERT) < tmp)
                                tmp = INT_GET(entry->nameidx, ARCH_CONVERT);
                }
                INT_SET(hdr->firstused, ARCH_CONVERT, tmp);
                if (!hdr->firstused)
                        INT_SET(hdr->firstused, ARCH_CONVERT, tmp - 1);
        } else {
                hdr->holes = 1;         /* mark as needing compaction */
        }

        xfs_da_log_buf(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  = (uint)sizeof(xfs_dir_leaf_hdr_t);
        tmp += INT_GET(leaf->hdr.count, ARCH_CONVERT) * (uint)sizeof(xfs_dir_leaf_entry_t);
        tmp += INT_GET(leaf->hdr.count, ARCH_CONVERT) * ((uint)sizeof(xfs_dir_leaf_name_t) - 1);
        tmp += INT_GET(leaf->hdr.namebytes, ARCH_CONVERT);
        if (tmp < mp->m_dir_magicpct)
                return(1);                      /* leaf is < 37% full */
        return(0);
}

/*
 * Move all the directory entries from drop_leaf into save_leaf.
 */
void
xfs_dir_leaf_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
                                      xfs_da_state_blk_t *save_blk)
{
        xfs_dir_leafblock_t *drop_leaf, *save_leaf, *tmp_leaf;
        xfs_dir_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_DIR_LEAF_MAGIC);
        ASSERT(save_blk->magic == XFS_DIR_LEAF_MAGIC);
        drop_leaf = drop_blk->bp->data;
        save_leaf = save_blk->bp->data;
        ASSERT(INT_GET(drop_leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        ASSERT(INT_GET(save_leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_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 = INT_GET(drop_leaf->entries[ drop_leaf->hdr.count-1 ].hashval, ARCH_CONVERT);

        /*
         * 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_dir_leaf_order(save_blk->bp, drop_blk->bp)) {
                        xfs_dir_leaf_moveents(drop_leaf, 0, save_leaf, 0,
                                                 (int)INT_GET(drop_hdr->count, ARCH_CONVERT), mp);
                } else {
                        xfs_dir_leaf_moveents(drop_leaf, 0,
                                              save_leaf, INT_GET(save_hdr->count, ARCH_CONVERT),
                                              (int)INT_GET(drop_hdr->count, ARCH_CONVERT), 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_dir_leafblock_t *)tmpbuffer;
                tmp_hdr = &tmp_leaf->hdr;
                tmp_hdr->info = save_hdr->info; /* struct copy */
                tmp_hdr->count = 0;
                INT_SET(tmp_hdr->firstused, ARCH_CONVERT, state->blocksize);
                if (!tmp_hdr->firstused)
                        INT_SET(tmp_hdr->firstused, ARCH_CONVERT, state->blocksize - 1);
                tmp_hdr->namebytes = 0;
                if (xfs_dir_leaf_order(save_blk->bp, drop_blk->bp)) {
                        xfs_dir_leaf_moveents(drop_leaf, 0, tmp_leaf, 0,
                                                 (int)INT_GET(drop_hdr->count, ARCH_CONVERT), mp);
                        xfs_dir_leaf_moveents(save_leaf, 0,
                                              tmp_leaf, INT_GET(tmp_leaf->hdr.count, ARCH_CONVERT),
                                              (int)INT_GET(save_hdr->count, ARCH_CONVERT), mp);
                } else {
                        xfs_dir_leaf_moveents(save_leaf, 0, tmp_leaf, 0,
                                                 (int)INT_GET(save_hdr->count, ARCH_CONVERT), mp);
                        xfs_dir_leaf_moveents(drop_leaf, 0,
                                              tmp_leaf, INT_GET(tmp_leaf->hdr.count, ARCH_CONVERT),
                                              (int)INT_GET(drop_hdr->count, ARCH_CONVERT), mp);
                }
                memcpy(save_leaf, tmp_leaf, state->blocksize);
                kmem_free(tmpbuffer, state->blocksize);
        }

        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 = INT_GET(save_leaf->entries[ INT_GET(save_leaf->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
}

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

/*
 * Look up a name in a leaf directory 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 *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->inumber unless we find the filename.
 */
int
xfs_dir_leaf_lookup_int(xfs_dabuf_t *bp, xfs_da_args_t *args, int *index)
{
        xfs_dir_leafblock_t *leaf;
        xfs_dir_leaf_entry_t *entry;
        xfs_dir_leaf_name_t *namest;
        int probe, span;
        xfs_dahash_t hashval;

        leaf = bp->data;
        ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        ASSERT(INT_GET(leaf->hdr.count, ARCH_CONVERT) < (XFS_LBSIZE(args->dp->i_mount)/8));

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

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

        /*
         * Duplicate keys may be present, so search all of them for a match.
         */
        while ((probe < INT_GET(leaf->hdr.count, ARCH_CONVERT)) && (INT_GET(entry->hashval, ARCH_CONVERT) == hashval)) {
                namest = XFS_DIR_LEAF_NAMESTRUCT(leaf, INT_GET(entry->nameidx, ARCH_CONVERT));
                if (entry->namelen == args->namelen &&
                    namest->name[0] == args->name[0] &&
                    memcmp(args->name, namest->name, args->namelen) == 0) {
                        XFS_DIR_SF_GET_DIRINO(&namest->inumber, &args->inumber);
                        *index = probe;
                        return(XFS_ERROR(EEXIST));
                }
                entry++;
                probe++;
        }
        *index = probe;
        ASSERT(probe == INT_GET(leaf->hdr.count, ARCH_CONVERT) || args->oknoent);
        return(XFS_ERROR(ENOENT));
}

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

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

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

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

        ASSERT(start_s < INT_GET(hdr_s->count, ARCH_CONVERT));
        ASSERT(start_d <= INT_GET(hdr_d->count, ARCH_CONVERT));
        ASSERT(count <= INT_GET(hdr_s->count, ARCH_CONVERT));

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

        /*
         * Copy all entry's in the same (sorted) order,
         * but allocate filenames packed and in sequence.
         */
        entry_s = &leaf_s->entries[start_s];
        entry_d = &leaf_d->entries[start_d];
        for (i = 0; i < count; entry_s++, entry_d++, i++) {
                ASSERT(INT_GET(entry_s->nameidx, ARCH_CONVERT) >= INT_GET(hdr_s->firstused, ARCH_CONVERT));
                tmp = XFS_DIR_LEAF_ENTSIZE_BYENTRY(entry_s);
                INT_MOD(hdr_d->firstused, ARCH_CONVERT, -(tmp));
                entry_d->hashval = entry_s->hashval; /* INT_: direct copy */
                INT_COPY(entry_d->nameidx, hdr_d->firstused, ARCH_CONVERT);
                entry_d->namelen = entry_s->namelen;
                ASSERT(INT_GET(entry_d->nameidx, ARCH_CONVERT) + tmp <= XFS_LBSIZE(mp));
                memcpy(XFS_DIR_LEAF_NAMESTRUCT(leaf_d, INT_GET(entry_d->nameidx, ARCH_CONVERT)),
                       XFS_DIR_LEAF_NAMESTRUCT(leaf_s, INT_GET(entry_s->nameidx, ARCH_CONVERT)), tmp);
                ASSERT(INT_GET(entry_s->nameidx, ARCH_CONVERT) + tmp <= XFS_LBSIZE(mp));
                memset((char *)XFS_DIR_LEAF_NAMESTRUCT(leaf_s, INT_GET(entry_s->nameidx, ARCH_CONVERT)),
                      0, tmp);
                INT_MOD(hdr_s->namebytes, ARCH_CONVERT, -(entry_d->namelen));
                INT_MOD(hdr_d->namebytes, ARCH_CONVERT, entry_d->namelen);
                INT_MOD(hdr_s->count, ARCH_CONVERT, -1);
                INT_MOD(hdr_d->count, ARCH_CONVERT, +1);
                tmp  = INT_GET(hdr_d->count, ARCH_CONVERT) * (uint)sizeof(xfs_dir_leaf_entry_t)
                                + (uint)sizeof(xfs_dir_leaf_hdr_t);
                ASSERT(INT_GET(hdr_d->firstused, ARCH_CONVERT) >= tmp);

        }

        /*
         * Zero out the entries we just copied.
         */
        if (start_s == INT_GET(hdr_s->count, ARCH_CONVERT)) {
                tmp = count * (uint)sizeof(xfs_dir_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  = INT_GET(hdr_s->count, ARCH_CONVERT) - count;
                tmp *= (uint)sizeof(xfs_dir_leaf_entry_t);
                entry_s = &leaf_s->entries[start_s + count];
                entry_d = &leaf_s->entries[start_s];
                memcpy(entry_d, entry_s, tmp);

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

        /*
         * Fill in the freemap information
         */
        INT_SET(hdr_d->freemap[0].base, ARCH_CONVERT, (uint)sizeof(xfs_dir_leaf_hdr_t));
        INT_MOD(hdr_d->freemap[0].base, ARCH_CONVERT, INT_GET(hdr_d->count, ARCH_CONVERT) * (uint)sizeof(xfs_dir_leaf_entry_t));
        INT_SET(hdr_d->freemap[0].size, ARCH_CONVERT, INT_GET(hdr_d->firstused, ARCH_CONVERT) - INT_GET(hdr_d->freemap[0].base, ARCH_CONVERT));
        INT_SET(hdr_d->freemap[1].base, ARCH_CONVERT, (hdr_d->freemap[2].base = 0));
        INT_SET(hdr_d->freemap[1].size, ARCH_CONVERT, (hdr_d->freemap[2].size = 0));
        hdr_s->holes = 1;       /* leaf may not be compact */
}

/*
 * Compare two leaf blocks "order".
 */
int
xfs_dir_leaf_order(xfs_dabuf_t *leaf1_bp, xfs_dabuf_t *leaf2_bp)
{
        xfs_dir_leafblock_t *leaf1, *leaf2;

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

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

        leaf = bp->data;
        ASSERT(INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC);
        if (count)
                *count = INT_GET(leaf->hdr.count, ARCH_CONVERT);
        if (!leaf->hdr.count)
                return(0);
        return(INT_GET(leaf->entries[ INT_GET(leaf->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT));
}

/*
 * Copy out directory entries for getdents(), for leaf directories.
 */
int
xfs_dir_leaf_getdents_int(
        xfs_dabuf_t     *bp,
        xfs_inode_t     *dp,
        xfs_dablk_t     bno,
        uio_t           *uio,
        int             *eobp,
        xfs_dirent_t    *dbp,
        xfs_dir_put_t   put,
        xfs_daddr_t             nextda)
{
        xfs_dir_leafblock_t     *leaf;
        xfs_dir_leaf_entry_t    *entry;
        xfs_dir_leaf_name_t     *namest;
        int                     entno, want_entno, i, nextentno;
        xfs_mount_t             *mp;
        xfs_dahash_t            cookhash;
        xfs_dahash_t            nexthash = 0;
#if (BITS_PER_LONG == 32)
        xfs_dahash_t            lasthash = XFS_DA_MAXHASH;
#endif
        xfs_dir_put_args_t      p;

        mp = dp->i_mount;
        leaf = bp->data;
        if (INT_GET(leaf->hdr.info.magic, ARCH_CONVERT) != XFS_DIR_LEAF_MAGIC) {
                *eobp = 1;
                return(XFS_ERROR(ENOENT));      /* XXX wrong code */
        }

        want_entno = XFS_DA_COOKIE_ENTRY(mp, uio->uio_offset);

        cookhash = XFS_DA_COOKIE_HASH(mp, uio->uio_offset);

        xfs_dir_trace_g_dul("leaf: start", dp, uio, leaf);

        /*
         * Re-find our place.
         */
        for (i = entno = 0, entry = &leaf->entries[0];
                     i < INT_GET(leaf->hdr.count, ARCH_CONVERT);
                             entry++, i++) {

                namest = XFS_DIR_LEAF_NAMESTRUCT(leaf,
                                    INT_GET(entry->nameidx, ARCH_CONVERT));

                if (unlikely(
                    ((char *)namest < (char *)leaf) ||
                    ((char *)namest >= (char *)leaf + XFS_LBSIZE(mp)))) {
                        XFS_CORRUPTION_ERROR("xfs_dir_leaf_getdents_int(1)",
                                             XFS_ERRLEVEL_LOW, mp, leaf);
                        xfs_dir_trace_g_du("leaf: corrupted", dp, uio);
                        return XFS_ERROR(EFSCORRUPTED);
                }
                if (INT_GET(entry->hashval, ARCH_CONVERT) >= cookhash) {
                        if (   entno < want_entno
                            && INT_GET(entry->hashval, ARCH_CONVERT)
                                                        == cookhash) {
                                /*
                                 * Trying to get to a particular offset in a
                                 * run of equal-hashval entries.
                                 */
                                entno++;
                        } else if (   want_entno > 0
                                   && entno == want_entno
                                   && INT_GET(entry->hashval, ARCH_CONVERT)
                                                        == cookhash) {
                                break;
                        } else {
                                entno = 0;
                                break;
                        }
                }
        }

        if (i == INT_GET(leaf->hdr.count, ARCH_CONVERT)) {
                xfs_dir_trace_g_du("leaf: hash not found", dp, uio);
                if (!INT_GET(leaf->hdr.info.forw, ARCH_CONVERT))
                        uio->uio_offset =
                                XFS_DA_MAKE_COOKIE(mp, 0, 0, XFS_DA_MAXHASH);
                /*
                 * Don't set uio_offset if there's another block:
                 * the node code will be setting uio_offset anyway.
                 */
                *eobp = 0;
                return(0);
        }
        xfs_dir_trace_g_due("leaf: hash found", dp, uio, entry);

        p.dbp = dbp;
        p.put = put;
        p.uio = uio;

        /*
         * We're synchronized, start copying entries out to the user.
         */
        for (; entno >= 0 && i < INT_GET(leaf->hdr.count, ARCH_CONVERT);
                             entry++, i++, (entno = nextentno)) {
                int lastresid=0, retval;
                xfs_dircook_t lastoffset;
                xfs_dahash_t thishash;

                /*
                 * Check for a damaged directory leaf block and pick up
                 * the inode number from this entry.
                 */
                namest = XFS_DIR_LEAF_NAMESTRUCT(leaf,
                                    INT_GET(entry->nameidx, ARCH_CONVERT));

                if (unlikely(
                    ((char *)namest < (char *)leaf) ||
                    ((char *)namest >= (char *)leaf + XFS_LBSIZE(mp)))) {
                        XFS_CORRUPTION_ERROR("xfs_dir_leaf_getdents_int(2)",
                                             XFS_ERRLEVEL_LOW, mp, leaf);
                        xfs_dir_trace_g_du("leaf: corrupted", dp, uio);
                        return XFS_ERROR(EFSCORRUPTED);
                }

                xfs_dir_trace_g_duc("leaf: middle cookie  ",
                                                   dp, uio, p.cook.o);

                if (i < (INT_GET(leaf->hdr.count, ARCH_CONVERT) - 1)) {
                        nexthash = INT_GET(entry[1].hashval, ARCH_CONVERT);

                        if (nexthash == INT_GET(entry->hashval, ARCH_CONVERT))
                                nextentno = entno + 1;
                        else
                                nextentno = 0;
                        XFS_PUT_COOKIE(p.cook, mp, bno, nextentno, nexthash);
                        xfs_dir_trace_g_duc("leaf: middle cookie  ",
                                                   dp, uio, p.cook.o);

                } else if ((thishash = INT_GET(leaf->hdr.info.forw,
                                                        ARCH_CONVERT))) {
                        xfs_dabuf_t *bp2;
                        xfs_dir_leafblock_t *leaf2;

                        ASSERT(nextda != -1);

                        retval = xfs_da_read_buf(dp->i_transp, dp, thishash,
                                                 nextda, &bp2, XFS_DATA_FORK);
                        if (retval)
                                return(retval);

                        ASSERT(bp2 != NULL);

                        leaf2 = bp2->data;

                        if (unlikely(
                               (INT_GET(leaf2->hdr.info.magic, ARCH_CONVERT)
                                                != XFS_DIR_LEAF_MAGIC)
                            || (INT_GET(leaf2->hdr.info.back, ARCH_CONVERT)
                                                != bno))) {     /* GROT */
                                XFS_CORRUPTION_ERROR("xfs_dir_leaf_getdents_int(3)",
                                                     XFS_ERRLEVEL_LOW, mp,
                                                     leaf2);
                                xfs_da_brelse(dp->i_transp, bp2);

                                return(XFS_ERROR(EFSCORRUPTED));
                        }

                        nexthash = INT_GET(leaf2->entries[0].hashval,
                                                                ARCH_CONVERT);
                        nextentno = -1;
                        XFS_PUT_COOKIE(p.cook, mp, thishash, 0, nexthash);
                        xfs_da_brelse(dp->i_transp, bp2);
                        xfs_dir_trace_g_duc("leaf: next blk cookie",
                                                   dp, uio, p.cook.o);
                } else {
                        nextentno = -1;
                        XFS_PUT_COOKIE(p.cook, mp, 0, 0, XFS_DA_MAXHASH);
                }

                /*
                 * Save off the cookie so we can fall back should the
                 * 'put' into the outgoing buffer fails.  To handle a run
                 * of equal-hashvals, the off_t structure on 64bit
                 * builds has entno built into the cookie to ID the
                 * entry.  On 32bit builds, we only have space for the
                 * hashval so we can't ID specific entries within a group
                 * of same hashval entries.   For this, lastoffset is set
                 * to the first in the run of equal hashvals so we don't
                 * include any entries unless we can include all entries
                 * that share the same hashval.  Hopefully the buffer
                 * provided is big enough to handle it (see pv763517).
                 */
#if (BITS_PER_LONG == 32)
                if ((thishash = INT_GET(entry->hashval, ARCH_CONVERT))
                                                                != lasthash) {
                        XFS_PUT_COOKIE(lastoffset, mp, bno, entno, thishash);
                        lastresid = uio->uio_resid;
                        lasthash = thishash;
                } else {
                        xfs_dir_trace_g_duc("leaf: DUP COOKIES, skipped",
                                                   dp, uio, p.cook.o);
                }
#else
                thishash = INT_GET(entry->hashval, ARCH_CONVERT);
                XFS_PUT_COOKIE(lastoffset, mp, bno, entno, thishash);
                lastresid = uio->uio_resid;
#endif /* BITS_PER_LONG == 32 */

                /*
                 * Put the current entry into the outgoing buffer.  If we fail
                 * then restore the UIO to the first entry in the current
                 * run of equal-hashval entries (probably one 1 entry long).
                 */
                p.ino = XFS_GET_DIR_INO8(namest->inumber);
#if XFS_BIG_INUMS
                p.ino += mp->m_inoadd;
#endif
                p.name = (char *)namest->name;
                p.namelen = entry->namelen;

                retval = p.put(&p);

                if (!p.done) {
                        uio->uio_offset = lastoffset.o;
                        uio->uio_resid = lastresid;

                        *eobp = 1;

                        xfs_dir_trace_g_du("leaf: E-O-B", dp, uio);

                        return(retval);
                }
        }

        uio->uio_offset = p.cook.o;

        *eobp = 0;

        xfs_dir_trace_g_du("leaf: E-O-F", dp, uio);

        return(0);
}

/*
 * Format a dirent64 structure and copy it out the the user's buffer.
 */
int
xfs_dir_put_dirent64_direct(xfs_dir_put_args_t *pa)
{
        iovec_t *iovp;
        int reclen, namelen;
        xfs_dirent_t *idbp;
        uio_t *uio;

        namelen = pa->namelen;
        reclen = DIRENTSIZE(namelen);
        uio = pa->uio;
        if (reclen > uio->uio_resid) {
                pa->done = 0;
                return 0;
        }
        iovp = uio->uio_iov;
        idbp = (xfs_dirent_t *)iovp->iov_base;
        iovp->iov_base = (char *)idbp + reclen;
        iovp->iov_len -= reclen;
        uio->uio_resid -= reclen;
        idbp->d_reclen = reclen;
        idbp->d_ino = pa->ino;
        idbp->d_off = pa->cook.o;
        idbp->d_name[namelen] = '\0';
        pa->done = 1;
        memcpy(idbp->d_name, pa->name, namelen);
        return 0;
}

/*
 * Format a dirent64 structure and copy it out the the user's buffer.
 */
int
xfs_dir_put_dirent64_uio(xfs_dir_put_args_t *pa)
{
        int             retval, reclen, namelen;
        xfs_dirent_t    *idbp;
        uio_t           *uio;

        namelen = pa->namelen;
        reclen = DIRENTSIZE(namelen);
        uio = pa->uio;
        if (reclen > uio->uio_resid) {
                pa->done = 0;
                return 0;
        }
        idbp = pa->dbp;
        idbp->d_reclen = reclen;
        idbp->d_ino = pa->ino;
        idbp->d_off = pa->cook.o;
        idbp->d_name[namelen] = '\0';
        memcpy(idbp->d_name, pa->name, namelen);
        retval = uio_read((caddr_t)idbp, reclen, uio);
        pa->done = (retval == 0);
        return retval;
}