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File: [Development] / xfs-linux / xfs_dir2_leaf.c (download)

Revision 1.60, Thu Dec 13 05:18:26 2007 UTC (9 years, 10 months ago) by dgc.longdrop.melbourne.sgi.com
Branch: MAIN
Changes since 1.59: +1 -1 lines

Put the correct offset in dirent d_off

The recent filldir regression fix was not putting the correct
d_off in each dirent. This was resulting in incorrect cookies being
passed to dmapi ioctls and the wrong offset appearing in the dirents.
readdir was unaffected as the filp->f_pos was being updated with the
correct offset and this was being written into the last dirent in
each buffer. Fix the XFS code to do the right thing.
Merge of xfs-linux-melb:xfs-kern:30240a by kenmcd.

  pass the current offset to the filldir method rather than the offset
  of the next object. filldir expects the current offset, not the next one.

/*
 * 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_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_attr_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_bmap.h"
#include "xfs_dir2_data.h"
#include "xfs_dir2_leaf.h"
#include "xfs_dir2_block.h"
#include "xfs_dir2_node.h"
#include "xfs_dir2_trace.h"
#include "xfs_error.h"

/*
 * Local function declarations.
 */
#ifdef DEBUG
static void xfs_dir2_leaf_check(xfs_inode_t *dp, xfs_dabuf_t *bp);
#else
#define	xfs_dir2_leaf_check(dp, bp)
#endif
static int xfs_dir2_leaf_lookup_int(xfs_da_args_t *args, xfs_dabuf_t **lbpp,
				    int *indexp, xfs_dabuf_t **dbpp);
static void xfs_dir2_leaf_log_bests(struct xfs_trans *tp, struct xfs_dabuf *bp,
				    int first, int last);
static void xfs_dir2_leaf_log_tail(struct xfs_trans *tp, struct xfs_dabuf *bp);


/*
 * Convert a block form directory to a leaf form directory.
 */
int						/* error */
xfs_dir2_block_to_leaf(
	xfs_da_args_t		*args,		/* operation arguments */
	xfs_dabuf_t		*dbp)		/* input block's buffer */
{
	__be16			*bestsp;	/* leaf's bestsp entries */
	xfs_dablk_t		blkno;		/* leaf block's bno */
	xfs_dir2_block_t	*block;		/* block structure */
	xfs_dir2_leaf_entry_t	*blp;		/* block's leaf entries */
	xfs_dir2_block_tail_t	*btp;		/* block's tail */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			error;		/* error return code */
	xfs_dabuf_t		*lbp;		/* leaf block's buffer */
	xfs_dir2_db_t		ldb;		/* leaf block's bno */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_tail_t	*ltp;		/* leaf's tail */
	xfs_mount_t		*mp;		/* filesystem mount point */
	int			needlog;	/* need to log block header */
	int			needscan;	/* need to rescan bestfree */
	xfs_trans_t		*tp;		/* transaction pointer */

	xfs_dir2_trace_args_b("block_to_leaf", args, dbp);
	dp = args->dp;
	mp = dp->i_mount;
	tp = args->trans;
	/*
	 * Add the leaf block to the inode.
	 * This interface will only put blocks in the leaf/node range.
	 * Since that's empty now, we'll get the root (block 0 in range).
	 */
	if ((error = xfs_da_grow_inode(args, &blkno))) {
		return error;
	}
	ldb = xfs_dir2_da_to_db(mp, blkno);
	ASSERT(ldb == XFS_DIR2_LEAF_FIRSTDB(mp));
	/*
	 * Initialize the leaf block, get a buffer for it.
	 */
	if ((error = xfs_dir2_leaf_init(args, ldb, &lbp, XFS_DIR2_LEAF1_MAGIC))) {
		return error;
	}
	ASSERT(lbp != NULL);
	leaf = lbp->data;
	block = dbp->data;
	xfs_dir2_data_check(dp, dbp);
	btp = xfs_dir2_block_tail_p(mp, block);
	blp = xfs_dir2_block_leaf_p(btp);
	/*
	 * Set the counts in the leaf header.
	 */
	leaf->hdr.count = cpu_to_be16(be32_to_cpu(btp->count));
	leaf->hdr.stale = cpu_to_be16(be32_to_cpu(btp->stale));
	/*
	 * Could compact these but I think we always do the conversion
	 * after squeezing out stale entries.
	 */
	memcpy(leaf->ents, blp, be32_to_cpu(btp->count) * sizeof(xfs_dir2_leaf_entry_t));
	xfs_dir2_leaf_log_ents(tp, lbp, 0, be16_to_cpu(leaf->hdr.count) - 1);
	needscan = 0;
	needlog = 1;
	/*
	 * Make the space formerly occupied by the leaf entries and block
	 * tail be free.
	 */
	xfs_dir2_data_make_free(tp, dbp,
		(xfs_dir2_data_aoff_t)((char *)blp - (char *)block),
		(xfs_dir2_data_aoff_t)((char *)block + mp->m_dirblksize -
				       (char *)blp),
		&needlog, &needscan);
	/*
	 * Fix up the block header, make it a data block.
	 */
	block->hdr.magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
	if (needscan)
		xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
	/*
	 * Set up leaf tail and bests table.
	 */
	ltp = xfs_dir2_leaf_tail_p(mp, leaf);
	ltp->bestcount = cpu_to_be32(1);
	bestsp = xfs_dir2_leaf_bests_p(ltp);
	bestsp[0] =  block->hdr.bestfree[0].length;
	/*
	 * Log the data header and leaf bests table.
	 */
	if (needlog)
		xfs_dir2_data_log_header(tp, dbp);
	xfs_dir2_leaf_check(dp, lbp);
	xfs_dir2_data_check(dp, dbp);
	xfs_dir2_leaf_log_bests(tp, lbp, 0, 0);
	xfs_da_buf_done(lbp);
	return 0;
}

/*
 * Add an entry to a leaf form directory.
 */
int						/* error */
xfs_dir2_leaf_addname(
	xfs_da_args_t		*args)		/* operation arguments */
{
	__be16			*bestsp;	/* freespace table in leaf */
	int			compact;	/* need to compact leaves */
	xfs_dir2_data_t		*data;		/* data block structure */
	xfs_dabuf_t		*dbp;		/* data block buffer */
	xfs_dir2_data_entry_t	*dep;		/* data block entry */
	xfs_inode_t		*dp;		/* incore directory inode */
	xfs_dir2_data_unused_t	*dup;		/* data unused entry */
	int			error;		/* error return value */
	int			grown;		/* allocated new data block */
	int			highstale;	/* index of next stale leaf */
	int			i;		/* temporary, index */
	int			index;		/* leaf table position */
	xfs_dabuf_t		*lbp;		/* leaf's buffer */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	int			length;		/* length of new entry */
	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry table pointer */
	int			lfloglow;	/* low leaf logging index */
	int			lfloghigh;	/* high leaf logging index */
	int			lowstale;	/* index of prev stale leaf */
	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail pointer */
	xfs_mount_t		*mp;		/* filesystem mount point */
	int			needbytes;	/* leaf block bytes needed */
	int			needlog;	/* need to log data header */
	int			needscan;	/* need to rescan data free */
	__be16			*tagp;		/* end of data entry */
	xfs_trans_t		*tp;		/* transaction pointer */
	xfs_dir2_db_t		use_block;	/* data block number */

	xfs_dir2_trace_args("leaf_addname", args);
	dp = args->dp;
	tp = args->trans;
	mp = dp->i_mount;
	/*
	 * Read the leaf block.
	 */
	error = xfs_da_read_buf(tp, dp, mp->m_dirleafblk, -1, &lbp,
		XFS_DATA_FORK);
	if (error) {
		return error;
	}
	ASSERT(lbp != NULL);
	/*
	 * Look up the entry by hash value and name.
	 * We know it's not there, our caller has already done a lookup.
	 * So the index is of the entry to insert in front of.
	 * But if there are dup hash values the index is of the first of those.
	 */
	index = xfs_dir2_leaf_search_hash(args, lbp);
	leaf = lbp->data;
	ltp = xfs_dir2_leaf_tail_p(mp, leaf);
	bestsp = xfs_dir2_leaf_bests_p(ltp);
	length = xfs_dir2_data_entsize(args->namelen);
	/*
	 * See if there are any entries with the same hash value
	 * and space in their block for the new entry.
	 * This is good because it puts multiple same-hash value entries
	 * in a data block, improving the lookup of those entries.
	 */
	for (use_block = -1, lep = &leaf->ents[index];
	     index < be16_to_cpu(leaf->hdr.count) && be32_to_cpu(lep->hashval) == args->hashval;
	     index++, lep++) {
		if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
			continue;
		i = xfs_dir2_dataptr_to_db(mp, be32_to_cpu(lep->address));
		ASSERT(i < be32_to_cpu(ltp->bestcount));
		ASSERT(be16_to_cpu(bestsp[i]) != NULLDATAOFF);
		if (be16_to_cpu(bestsp[i]) >= length) {
			use_block = i;
			break;
		}
	}
	/*
	 * Didn't find a block yet, linear search all the data blocks.
	 */
	if (use_block == -1) {
		for (i = 0; i < be32_to_cpu(ltp->bestcount); i++) {
			/*
			 * Remember a block we see that's missing.
			 */
			if (be16_to_cpu(bestsp[i]) == NULLDATAOFF && use_block == -1)
				use_block = i;
			else if (be16_to_cpu(bestsp[i]) >= length) {
				use_block = i;
				break;
			}
		}
	}
	/*
	 * How many bytes do we need in the leaf block?
	 */
	needbytes =
		(leaf->hdr.stale ? 0 : (uint)sizeof(leaf->ents[0])) +
		(use_block != -1 ? 0 : (uint)sizeof(leaf->bests[0]));
	/*
	 * Now kill use_block if it refers to a missing block, so we
	 * can use it as an indication of allocation needed.
	 */
	if (use_block != -1 && be16_to_cpu(bestsp[use_block]) == NULLDATAOFF)
		use_block = -1;
	/*
	 * If we don't have enough free bytes but we can make enough
	 * by compacting out stale entries, we'll do that.
	 */
	if ((char *)bestsp - (char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] < needbytes &&
	    be16_to_cpu(leaf->hdr.stale) > 1) {
		compact = 1;
	}
	/*
	 * Otherwise if we don't have enough free bytes we need to
	 * convert to node form.
	 */
	else if ((char *)bestsp - (char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] <
		 needbytes) {
		/*
		 * Just checking or no space reservation, give up.
		 */
		if (args->justcheck || args->total == 0) {
			xfs_da_brelse(tp, lbp);
			return XFS_ERROR(ENOSPC);
		}
		/*
		 * Convert to node form.
		 */
		error = xfs_dir2_leaf_to_node(args, lbp);
		xfs_da_buf_done(lbp);
		if (error)
			return error;
		/*
		 * Then add the new entry.
		 */
		return xfs_dir2_node_addname(args);
	}
	/*
	 * Otherwise it will fit without compaction.
	 */
	else
		compact = 0;
	/*
	 * If just checking, then it will fit unless we needed to allocate
	 * a new data block.
	 */
	if (args->justcheck) {
		xfs_da_brelse(tp, lbp);
		return use_block == -1 ? XFS_ERROR(ENOSPC) : 0;
	}
	/*
	 * If no allocations are allowed, return now before we've
	 * changed anything.
	 */
	if (args->total == 0 && use_block == -1) {
		xfs_da_brelse(tp, lbp);
		return XFS_ERROR(ENOSPC);
	}
	/*
	 * Need to compact the leaf entries, removing stale ones.
	 * Leave one stale entry behind - the one closest to our
	 * insertion index - and we'll shift that one to our insertion
	 * point later.
	 */
	if (compact) {
		xfs_dir2_leaf_compact_x1(lbp, &index, &lowstale, &highstale,
			&lfloglow, &lfloghigh);
	}
	/*
	 * There are stale entries, so we'll need log-low and log-high
	 * impossibly bad values later.
	 */
	else if (be16_to_cpu(leaf->hdr.stale)) {
		lfloglow = be16_to_cpu(leaf->hdr.count);
		lfloghigh = -1;
	}
	/*
	 * If there was no data block space found, we need to allocate
	 * a new one.
	 */
	if (use_block == -1) {
		/*
		 * Add the new data block.
		 */
		if ((error = xfs_dir2_grow_inode(args, XFS_DIR2_DATA_SPACE,
				&use_block))) {
			xfs_da_brelse(tp, lbp);
			return error;
		}
		/*
		 * Initialize the block.
		 */
		if ((error = xfs_dir2_data_init(args, use_block, &dbp))) {
			xfs_da_brelse(tp, lbp);
			return error;
		}
		/*
		 * If we're adding a new data block on the end we need to
		 * extend the bests table.  Copy it up one entry.
		 */
		if (use_block >= be32_to_cpu(ltp->bestcount)) {
			bestsp--;
			memmove(&bestsp[0], &bestsp[1],
				be32_to_cpu(ltp->bestcount) * sizeof(bestsp[0]));
			be32_add(&ltp->bestcount, 1);
			xfs_dir2_leaf_log_tail(tp, lbp);
			xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
		}
		/*
		 * If we're filling in a previously empty block just log it.
		 */
		else
			xfs_dir2_leaf_log_bests(tp, lbp, use_block, use_block);
		data = dbp->data;
		bestsp[use_block] = data->hdr.bestfree[0].length;
		grown = 1;
	}
	/*
	 * Already had space in some data block.
	 * Just read that one in.
	 */
	else {
		if ((error =
		    xfs_da_read_buf(tp, dp, xfs_dir2_db_to_da(mp, use_block),
			    -1, &dbp, XFS_DATA_FORK))) {
			xfs_da_brelse(tp, lbp);
			return error;
		}
		data = dbp->data;
		grown = 0;
	}
	xfs_dir2_data_check(dp, dbp);
	/*
	 * Point to the biggest freespace in our data block.
	 */
	dup = (xfs_dir2_data_unused_t *)
	      ((char *)data + be16_to_cpu(data->hdr.bestfree[0].offset));
	ASSERT(be16_to_cpu(dup->length) >= length);
	needscan = needlog = 0;
	/*
	 * Mark the initial part of our freespace in use for the new entry.
	 */
	xfs_dir2_data_use_free(tp, dbp, dup,
		(xfs_dir2_data_aoff_t)((char *)dup - (char *)data), length,
		&needlog, &needscan);
	/*
	 * Initialize our new entry (at last).
	 */
	dep = (xfs_dir2_data_entry_t *)dup;
	dep->inumber = cpu_to_be64(args->inumber);
	dep->namelen = args->namelen;
	memcpy(dep->name, args->name, dep->namelen);
	tagp = xfs_dir2_data_entry_tag_p(dep);
	*tagp = cpu_to_be16((char *)dep - (char *)data);
	/*
	 * Need to scan fix up the bestfree table.
	 */
	if (needscan)
		xfs_dir2_data_freescan(mp, data, &needlog);
	/*
	 * Need to log the data block's header.
	 */
	if (needlog)
		xfs_dir2_data_log_header(tp, dbp);
	xfs_dir2_data_log_entry(tp, dbp, dep);
	/*
	 * If the bests table needs to be changed, do it.
	 * Log the change unless we've already done that.
	 */
	if (be16_to_cpu(bestsp[use_block]) != be16_to_cpu(data->hdr.bestfree[0].length)) {
		bestsp[use_block] = data->hdr.bestfree[0].length;
		if (!grown)
			xfs_dir2_leaf_log_bests(tp, lbp, use_block, use_block);
	}
	/*
	 * Now we need to make room to insert the leaf entry.
	 * If there are no stale entries, we just insert a hole at index.
	 */
	if (!leaf->hdr.stale) {
		/*
		 * lep is still good as the index leaf entry.
		 */
		if (index < be16_to_cpu(leaf->hdr.count))
			memmove(lep + 1, lep,
				(be16_to_cpu(leaf->hdr.count) - index) * sizeof(*lep));
		/*
		 * Record low and high logging indices for the leaf.
		 */
		lfloglow = index;
		lfloghigh = be16_to_cpu(leaf->hdr.count);
		be16_add(&leaf->hdr.count, 1);
	}
	/*
	 * There are stale entries.
	 * We will use one of them for the new entry.
	 * It's probably not at the right location, so we'll have to
	 * shift some up or down first.
	 */
	else {
		/*
		 * If we didn't compact before, we need to find the nearest
		 * stale entries before and after our insertion point.
		 */
		if (compact == 0) {
			/*
			 * Find the first stale entry before the insertion
			 * point, if any.
			 */
			for (lowstale = index - 1;
			     lowstale >= 0 &&
				be32_to_cpu(leaf->ents[lowstale].address) !=
				XFS_DIR2_NULL_DATAPTR;
			     lowstale--)
				continue;
			/*
			 * Find the next stale entry at or after the insertion
			 * point, if any.   Stop if we go so far that the
			 * lowstale entry would be better.
			 */
			for (highstale = index;
			     highstale < be16_to_cpu(leaf->hdr.count) &&
				be32_to_cpu(leaf->ents[highstale].address) !=
				XFS_DIR2_NULL_DATAPTR &&
				(lowstale < 0 ||
				 index - lowstale - 1 >= highstale - index);
			     highstale++)
				continue;
		}
		/*
		 * If the low one is better, use it.
		 */
		if (lowstale >= 0 &&
		    (highstale == be16_to_cpu(leaf->hdr.count) ||
		     index - lowstale - 1 < highstale - index)) {
			ASSERT(index - lowstale - 1 >= 0);
			ASSERT(be32_to_cpu(leaf->ents[lowstale].address) ==
			       XFS_DIR2_NULL_DATAPTR);
			/*
			 * Copy entries up to cover the stale entry
			 * and make room for the new entry.
			 */
			if (index - lowstale - 1 > 0)
				memmove(&leaf->ents[lowstale],
					&leaf->ents[lowstale + 1],
					(index - lowstale - 1) * sizeof(*lep));
			lep = &leaf->ents[index - 1];
			lfloglow = MIN(lowstale, lfloglow);
			lfloghigh = MAX(index - 1, lfloghigh);
		}
		/*
		 * The high one is better, so use that one.
		 */
		else {
			ASSERT(highstale - index >= 0);
			ASSERT(be32_to_cpu(leaf->ents[highstale].address) ==
			       XFS_DIR2_NULL_DATAPTR);
			/*
			 * Copy entries down to cover the stale entry
			 * and make room for the new entry.
			 */
			if (highstale - index > 0)
				memmove(&leaf->ents[index + 1],
					&leaf->ents[index],
					(highstale - index) * sizeof(*lep));
			lep = &leaf->ents[index];
			lfloglow = MIN(index, lfloglow);
			lfloghigh = MAX(highstale, lfloghigh);
		}
		be16_add(&leaf->hdr.stale, -1);
	}
	/*
	 * Fill in the new leaf entry.
	 */
	lep->hashval = cpu_to_be32(args->hashval);
	lep->address = cpu_to_be32(xfs_dir2_db_off_to_dataptr(mp, use_block,
				be16_to_cpu(*tagp)));
	/*
	 * Log the leaf fields and give up the buffers.
	 */
	xfs_dir2_leaf_log_header(tp, lbp);
	xfs_dir2_leaf_log_ents(tp, lbp, lfloglow, lfloghigh);
	xfs_dir2_leaf_check(dp, lbp);
	xfs_da_buf_done(lbp);
	xfs_dir2_data_check(dp, dbp);
	xfs_da_buf_done(dbp);
	return 0;
}

#ifdef DEBUG
/*
 * Check the internal consistency of a leaf1 block.
 * Pop an assert if something is wrong.
 */
void
xfs_dir2_leaf_check(
	xfs_inode_t		*dp,		/* incore directory inode */
	xfs_dabuf_t		*bp)		/* leaf's buffer */
{
	int			i;		/* leaf index */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail pointer */
	xfs_mount_t		*mp;		/* filesystem mount point */
	int			stale;		/* count of stale leaves */

	leaf = bp->data;
	mp = dp->i_mount;
	ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
	/*
	 * This value is not restrictive enough.
	 * Should factor in the size of the bests table as well.
	 * We can deduce a value for that from di_size.
	 */
	ASSERT(be16_to_cpu(leaf->hdr.count) <= xfs_dir2_max_leaf_ents(mp));
	ltp = xfs_dir2_leaf_tail_p(mp, leaf);
	/*
	 * Leaves and bests don't overlap.
	 */
	ASSERT((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] <=
	       (char *)xfs_dir2_leaf_bests_p(ltp));
	/*
	 * Check hash value order, count stale entries.
	 */
	for (i = stale = 0; i < be16_to_cpu(leaf->hdr.count); i++) {
		if (i + 1 < be16_to_cpu(leaf->hdr.count))
			ASSERT(be32_to_cpu(leaf->ents[i].hashval) <=
			       be32_to_cpu(leaf->ents[i + 1].hashval));
		if (be32_to_cpu(leaf->ents[i].address) == XFS_DIR2_NULL_DATAPTR)
			stale++;
	}
	ASSERT(be16_to_cpu(leaf->hdr.stale) == stale);
}
#endif	/* DEBUG */

/*
 * Compact out any stale entries in the leaf.
 * Log the header and changed leaf entries, if any.
 */
void
xfs_dir2_leaf_compact(
	xfs_da_args_t	*args,		/* operation arguments */
	xfs_dabuf_t	*bp)		/* leaf buffer */
{
	int		from;		/* source leaf index */
	xfs_dir2_leaf_t	*leaf;		/* leaf structure */
	int		loglow;		/* first leaf entry to log */
	int		to;		/* target leaf index */

	leaf = bp->data;
	if (!leaf->hdr.stale) {
		return;
	}
	/*
	 * Compress out the stale entries in place.
	 */
	for (from = to = 0, loglow = -1; from < be16_to_cpu(leaf->hdr.count); from++) {
		if (be32_to_cpu(leaf->ents[from].address) == XFS_DIR2_NULL_DATAPTR)
			continue;
		/*
		 * Only actually copy the entries that are different.
		 */
		if (from > to) {
			if (loglow == -1)
				loglow = to;
			leaf->ents[to] = leaf->ents[from];
		}
		to++;
	}
	/*
	 * Update and log the header, log the leaf entries.
	 */
	ASSERT(be16_to_cpu(leaf->hdr.stale) == from - to);
	be16_add(&leaf->hdr.count, -(be16_to_cpu(leaf->hdr.stale)));
	leaf->hdr.stale = 0;
	xfs_dir2_leaf_log_header(args->trans, bp);
	if (loglow != -1)
		xfs_dir2_leaf_log_ents(args->trans, bp, loglow, to - 1);
}

/*
 * Compact the leaf entries, removing stale ones.
 * Leave one stale entry behind - the one closest to our
 * insertion index - and the caller will shift that one to our insertion
 * point later.
 * Return new insertion index, where the remaining stale entry is,
 * and leaf logging indices.
 */
void
xfs_dir2_leaf_compact_x1(
	xfs_dabuf_t	*bp,		/* leaf buffer */
	int		*indexp,	/* insertion index */
	int		*lowstalep,	/* out: stale entry before us */
	int		*highstalep,	/* out: stale entry after us */
	int		*lowlogp,	/* out: low log index */
	int		*highlogp)	/* out: high log index */
{
	int		from;		/* source copy index */
	int		highstale;	/* stale entry at/after index */
	int		index;		/* insertion index */
	int		keepstale;	/* source index of kept stale */
	xfs_dir2_leaf_t	*leaf;		/* leaf structure */
	int		lowstale;	/* stale entry before index */
	int		newindex=0;	/* new insertion index */
	int		to;		/* destination copy index */

	leaf = bp->data;
	ASSERT(be16_to_cpu(leaf->hdr.stale) > 1);
	index = *indexp;
	/*
	 * Find the first stale entry before our index, if any.
	 */
	for (lowstale = index - 1;
	     lowstale >= 0 &&
		be32_to_cpu(leaf->ents[lowstale].address) != XFS_DIR2_NULL_DATAPTR;
	     lowstale--)
		continue;
	/*
	 * Find the first stale entry at or after our index, if any.
	 * Stop if the answer would be worse than lowstale.
	 */
	for (highstale = index;
	     highstale < be16_to_cpu(leaf->hdr.count) &&
		be32_to_cpu(leaf->ents[highstale].address) != XFS_DIR2_NULL_DATAPTR &&
		(lowstale < 0 || index - lowstale > highstale - index);
	     highstale++)
		continue;
	/*
	 * Pick the better of lowstale and highstale.
	 */
	if (lowstale >= 0 &&
	    (highstale == be16_to_cpu(leaf->hdr.count) ||
	     index - lowstale <= highstale - index))
		keepstale = lowstale;
	else
		keepstale = highstale;
	/*
	 * Copy the entries in place, removing all the stale entries
	 * except keepstale.
	 */
	for (from = to = 0; from < be16_to_cpu(leaf->hdr.count); from++) {
		/*
		 * Notice the new value of index.
		 */
		if (index == from)
			newindex = to;
		if (from != keepstale &&
		    be32_to_cpu(leaf->ents[from].address) == XFS_DIR2_NULL_DATAPTR) {
			if (from == to)
				*lowlogp = to;
			continue;
		}
		/*
		 * Record the new keepstale value for the insertion.
		 */
		if (from == keepstale)
			lowstale = highstale = to;
		/*
		 * Copy only the entries that have moved.
		 */
		if (from > to)
			leaf->ents[to] = leaf->ents[from];
		to++;
	}
	ASSERT(from > to);
	/*
	 * If the insertion point was past the last entry,
	 * set the new insertion point accordingly.
	 */
	if (index == from)
		newindex = to;
	*indexp = newindex;
	/*
	 * Adjust the leaf header values.
	 */
	be16_add(&leaf->hdr.count, -(from - to));
	leaf->hdr.stale = cpu_to_be16(1);
	/*
	 * Remember the low/high stale value only in the "right"
	 * direction.
	 */
	if (lowstale >= newindex)
		lowstale = -1;
	else
		highstale = be16_to_cpu(leaf->hdr.count);
	*highlogp = be16_to_cpu(leaf->hdr.count) - 1;
	*lowstalep = lowstale;
	*highstalep = highstale;
}

/*
 * Getdents (readdir) for leaf and node directories.
 * This reads the data blocks only, so is the same for both forms.
 */
int						/* error */
xfs_dir2_leaf_getdents(
	xfs_inode_t		*dp,		/* incore directory inode */
	void			*dirent,
	size_t			bufsize,
	xfs_off_t		*offset,
	filldir_t		filldir)
{
	xfs_dabuf_t		*bp;		/* data block buffer */
	int			byteoff;	/* offset in current block */
	xfs_dir2_db_t		curdb;		/* db for current block */
	xfs_dir2_off_t		curoff;		/* current overall offset */
	xfs_dir2_data_t		*data;		/* data block structure */
	xfs_dir2_data_entry_t	*dep;		/* data entry */
	xfs_dir2_data_unused_t	*dup;		/* unused entry */
	int			error = 0;	/* error return value */
	int			i;		/* temporary loop index */
	int			j;		/* temporary loop index */
	int			length;		/* temporary length value */
	xfs_bmbt_irec_t		*map;		/* map vector for blocks */
	xfs_extlen_t		map_blocks;	/* number of fsbs in map */
	xfs_dablk_t		map_off;	/* last mapped file offset */
	int			map_size;	/* total entries in *map */
	int			map_valid;	/* valid entries in *map */
	xfs_mount_t		*mp;		/* filesystem mount point */
	xfs_dir2_off_t		newoff;		/* new curoff after new blk */
	int			nmap;		/* mappings to ask xfs_bmapi */
	char			*ptr = NULL;	/* pointer to current data */
	int			ra_current;	/* number of read-ahead blks */
	int			ra_index;	/* *map index for read-ahead */
	int			ra_offset;	/* map entry offset for ra */
	int			ra_want;	/* readahead count wanted */
	xfs_ino_t		ino;

	/*
	 * If the offset is at or past the largest allowed value,
	 * give up right away.
	 */
	if (*offset >= XFS_DIR2_MAX_DATAPTR)
		return 0;

	mp = dp->i_mount;

	/*
	 * Set up to bmap a number of blocks based on the caller's
	 * buffer size, the directory block size, and the filesystem
	 * block size.
	 */
	map_size = howmany(bufsize + mp->m_dirblksize, mp->m_sb.sb_blocksize);
	map = kmem_alloc(map_size * sizeof(*map), KM_SLEEP);
	map_valid = ra_index = ra_offset = ra_current = map_blocks = 0;
	bp = NULL;

	/*
	 * Inside the loop we keep the main offset value as a byte offset
	 * in the directory file.
	 */
	curoff = xfs_dir2_dataptr_to_byte(mp, *offset);

	/*
	 * Force this conversion through db so we truncate the offset
	 * down to get the start of the data block.
	 */
	map_off = xfs_dir2_db_to_da(mp, xfs_dir2_byte_to_db(mp, curoff));
	/*
	 * Loop over directory entries until we reach the end offset.
	 * Get more blocks and readahead as necessary.
	 */
	while (curoff < XFS_DIR2_LEAF_OFFSET) {
		/*
		 * If we have no buffer, or we're off the end of the
		 * current buffer, need to get another one.
		 */
		if (!bp || ptr >= (char *)bp->data + mp->m_dirblksize) {
			/*
			 * If we have a buffer, we need to release it and
			 * take it out of the mapping.
			 */
			if (bp) {
				xfs_da_brelse(NULL, bp);
				bp = NULL;
				map_blocks -= mp->m_dirblkfsbs;
				/*
				 * Loop to get rid of the extents for the
				 * directory block.
				 */
				for (i = mp->m_dirblkfsbs; i > 0; ) {
					j = MIN((int)map->br_blockcount, i);
					map->br_blockcount -= j;
					map->br_startblock += j;
					map->br_startoff += j;
					/*
					 * If mapping is done, pitch it from
					 * the table.
					 */
					if (!map->br_blockcount && --map_valid)
						memmove(&map[0], &map[1],
							sizeof(map[0]) *
							map_valid);
					i -= j;
				}
			}
			/*
			 * Recalculate the readahead blocks wanted.
			 */
			ra_want = howmany(bufsize + mp->m_dirblksize,
					  mp->m_sb.sb_blocksize) - 1;

			/*
			 * If we don't have as many as we want, and we haven't
			 * run out of data blocks, get some more mappings.
			 */
			if (1 + ra_want > map_blocks &&
			    map_off <
			    xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET)) {
				/*
				 * Get more bmaps, fill in after the ones
				 * we already have in the table.
				 */
				nmap = map_size - map_valid;
				error = xfs_bmapi(NULL, dp,
					map_off,
					xfs_dir2_byte_to_da(mp,
						XFS_DIR2_LEAF_OFFSET) - map_off,
					XFS_BMAPI_METADATA, NULL, 0,
					&map[map_valid], &nmap, NULL, NULL);
				/*
				 * Don't know if we should ignore this or
				 * try to return an error.
				 * The trouble with returning errors
				 * is that readdir will just stop without
				 * actually passing the error through.
				 */
				if (error)
					break;	/* XXX */
				/*
				 * If we got all the mappings we asked for,
				 * set the final map offset based on the
				 * last bmap value received.
				 * Otherwise, we've reached the end.
				 */
				if (nmap == map_size - map_valid)
					map_off =
					map[map_valid + nmap - 1].br_startoff +
					map[map_valid + nmap - 1].br_blockcount;
				else
					map_off =
						xfs_dir2_byte_to_da(mp,
							XFS_DIR2_LEAF_OFFSET);
				/*
				 * Look for holes in the mapping, and
				 * eliminate them.  Count up the valid blocks.
				 */
				for (i = map_valid; i < map_valid + nmap; ) {
					if (map[i].br_startblock ==
					    HOLESTARTBLOCK) {
						nmap--;
						length = map_valid + nmap - i;
						if (length)
							memmove(&map[i],
								&map[i + 1],
								sizeof(map[i]) *
								length);
					} else {
						map_blocks +=
							map[i].br_blockcount;
						i++;
					}
				}
				map_valid += nmap;
			}
			/*
			 * No valid mappings, so no more data blocks.
			 */
			if (!map_valid) {
				curoff = xfs_dir2_da_to_byte(mp, map_off);
				break;
			}
			/*
			 * Read the directory block starting at the first
			 * mapping.
			 */
			curdb = xfs_dir2_da_to_db(mp, map->br_startoff);
			error = xfs_da_read_buf(NULL, dp, map->br_startoff,
				map->br_blockcount >= mp->m_dirblkfsbs ?
				    XFS_FSB_TO_DADDR(mp, map->br_startblock) :
				    -1,
				&bp, XFS_DATA_FORK);
			/*
			 * Should just skip over the data block instead
			 * of giving up.
			 */
			if (error)
				break;	/* XXX */
			/*
			 * Adjust the current amount of read-ahead: we just
			 * read a block that was previously ra.
			 */
			if (ra_current)
				ra_current -= mp->m_dirblkfsbs;
			/*
			 * Do we need more readahead?
			 */
			for (ra_index = ra_offset = i = 0;
			     ra_want > ra_current && i < map_blocks;
			     i += mp->m_dirblkfsbs) {
				ASSERT(ra_index < map_valid);
				/*
				 * Read-ahead a contiguous directory block.
				 */
				if (i > ra_current &&
				    map[ra_index].br_blockcount >=
				    mp->m_dirblkfsbs) {
					xfs_baread(mp->m_ddev_targp,
						XFS_FSB_TO_DADDR(mp,
						   map[ra_index].br_startblock +
						   ra_offset),
						(int)BTOBB(mp->m_dirblksize));
					ra_current = i;
				}
				/*
				 * Read-ahead a non-contiguous directory block.
				 * This doesn't use our mapping, but this
				 * is a very rare case.
				 */
				else if (i > ra_current) {
					(void)xfs_da_reada_buf(NULL, dp,
						map[ra_index].br_startoff +
						ra_offset, XFS_DATA_FORK);
					ra_current = i;
				}
				/*
				 * Advance offset through the mapping table.
				 */
				for (j = 0; j < mp->m_dirblkfsbs; j++) {
					/*
					 * The rest of this extent but not
					 * more than a dir block.
					 */
					length = MIN(mp->m_dirblkfsbs,
						(int)(map[ra_index].br_blockcount -
						ra_offset));
					j += length;
					ra_offset += length;
					/*
					 * Advance to the next mapping if
					 * this one is used up.
					 */
					if (ra_offset ==
					    map[ra_index].br_blockcount) {
						ra_offset = 0;
						ra_index++;
					}
				}
			}
			/*
			 * Having done a read, we need to set a new offset.
			 */
			newoff = xfs_dir2_db_off_to_byte(mp, curdb, 0);
			/*
			 * Start of the current block.
			 */
			if (curoff < newoff)
				curoff = newoff;
			/*
			 * Make sure we're in the right block.
			 */
			else if (curoff > newoff)
				ASSERT(xfs_dir2_byte_to_db(mp, curoff) ==
				       curdb);
			data = bp->data;
			xfs_dir2_data_check(dp, bp);
			/*
			 * Find our position in the block.
			 */
			ptr = (char *)&data->u;
			byteoff = xfs_dir2_byte_to_off(mp, curoff);
			/*
			 * Skip past the header.
			 */
			if (byteoff == 0)
				curoff += (uint)sizeof(data->hdr);
			/*
			 * Skip past entries until we reach our offset.
			 */
			else {
				while ((char *)ptr - (char *)data < byteoff) {
					dup = (xfs_dir2_data_unused_t *)ptr;

					if (be16_to_cpu(dup->freetag)
						  == XFS_DIR2_DATA_FREE_TAG) {

						length = be16_to_cpu(dup->length);
						ptr += length;
						continue;
					}
					dep = (xfs_dir2_data_entry_t *)ptr;
					length =
					   xfs_dir2_data_entsize(dep->namelen);
					ptr += length;
				}
				/*
				 * Now set our real offset.
				 */
				curoff =
					xfs_dir2_db_off_to_byte(mp,
					    xfs_dir2_byte_to_db(mp, curoff),
					    (char *)ptr - (char *)data);
				if (ptr >= (char *)data + mp->m_dirblksize) {
					continue;
				}
			}
		}
		/*
		 * We have a pointer to an entry.
		 * Is it a live one?
		 */
		dup = (xfs_dir2_data_unused_t *)ptr;
		/*
		 * No, it's unused, skip over it.
		 */
		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
			length = be16_to_cpu(dup->length);
			ptr += length;
			curoff += length;
			continue;
		}

		/*
		 * Copy the entry into the putargs, and try formatting it.
		 */
		dep = (xfs_dir2_data_entry_t *)ptr;

		length = xfs_dir2_data_entsize(dep->namelen);

		ino = be64_to_cpu(dep->inumber);
#if XFS_BIG_INUMS
		ino += mp->m_inoadd;
#endif

		/*
		 * Won't fit.  Return to caller.
		 */
		if (filldir(dirent, dep->name, dep->namelen,
			    xfs_dir2_byte_to_dataptr(mp, curoff),
			    ino, DT_UNKNOWN))
			break;

		/*
		 * Advance to next entry in the block.
		 */
		ptr += length;
		curoff += length;
		bufsize -= length;
	}

	/*
	 * All done.  Set output offset value to current offset.
	 */
	if (curoff > xfs_dir2_dataptr_to_byte(mp, XFS_DIR2_MAX_DATAPTR))
		*offset = XFS_DIR2_MAX_DATAPTR;
	else
		*offset = xfs_dir2_byte_to_dataptr(mp, curoff);
	kmem_free(map, map_size * sizeof(*map));
	if (bp)
		xfs_da_brelse(NULL, bp);
	return error;
}

/*
 * Initialize a new leaf block, leaf1 or leafn magic accepted.
 */
int
xfs_dir2_leaf_init(
	xfs_da_args_t		*args,		/* operation arguments */
	xfs_dir2_db_t		bno,		/* directory block number */
	xfs_dabuf_t		**bpp,		/* out: leaf buffer */
	int			magic)		/* magic number for block */
{
	xfs_dabuf_t		*bp;		/* leaf buffer */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			error;		/* error return code */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
	xfs_mount_t		*mp;		/* filesystem mount point */
	xfs_trans_t		*tp;		/* transaction pointer */

	dp = args->dp;
	ASSERT(dp != NULL);
	tp = args->trans;
	mp = dp->i_mount;
	ASSERT(bno >= XFS_DIR2_LEAF_FIRSTDB(mp) &&
	       bno < XFS_DIR2_FREE_FIRSTDB(mp));
	/*
	 * Get the buffer for the block.
	 */
	error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, bno), -1, &bp,
		XFS_DATA_FORK);
	if (error) {
		return error;
	}
	ASSERT(bp != NULL);
	leaf = bp->data;
	/*
	 * Initialize the header.
	 */
	leaf->hdr.info.magic = cpu_to_be16(magic);
	leaf->hdr.info.forw = 0;
	leaf->hdr.info.back = 0;
	leaf->hdr.count = 0;
	leaf->hdr.stale = 0;
	xfs_dir2_leaf_log_header(tp, bp);
	/*
	 * If it's a leaf-format directory initialize the tail.
	 * In this case our caller has the real bests table to copy into
	 * the block.
	 */
	if (magic == XFS_DIR2_LEAF1_MAGIC) {
		ltp = xfs_dir2_leaf_tail_p(mp, leaf);
		ltp->bestcount = 0;
		xfs_dir2_leaf_log_tail(tp, bp);
	}
	*bpp = bp;
	return 0;
}

/*
 * Log the bests entries indicated from a leaf1 block.
 */
static void
xfs_dir2_leaf_log_bests(
	xfs_trans_t		*tp,		/* transaction pointer */
	xfs_dabuf_t		*bp,		/* leaf buffer */
	int			first,		/* first entry to log */
	int			last)		/* last entry to log */
{
	__be16			*firstb;	/* pointer to first entry */
	__be16			*lastb;		/* pointer to last entry */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */

	leaf = bp->data;
	ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
	ltp = xfs_dir2_leaf_tail_p(tp->t_mountp, leaf);
	firstb = xfs_dir2_leaf_bests_p(ltp) + first;
	lastb = xfs_dir2_leaf_bests_p(ltp) + last;
	xfs_da_log_buf(tp, bp, (uint)((char *)firstb - (char *)leaf),
		(uint)((char *)lastb - (char *)leaf + sizeof(*lastb) - 1));
}

/*
 * Log the leaf entries indicated from a leaf1 or leafn block.
 */
void
xfs_dir2_leaf_log_ents(
	xfs_trans_t		*tp,		/* transaction pointer */
	xfs_dabuf_t		*bp,		/* leaf buffer */
	int			first,		/* first entry to log */
	int			last)		/* last entry to log */
{
	xfs_dir2_leaf_entry_t	*firstlep;	/* pointer to first entry */
	xfs_dir2_leaf_entry_t	*lastlep;	/* pointer to last entry */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */

	leaf = bp->data;
	ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC ||
	       be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
	firstlep = &leaf->ents[first];
	lastlep = &leaf->ents[last];
	xfs_da_log_buf(tp, bp, (uint)((char *)firstlep - (char *)leaf),
		(uint)((char *)lastlep - (char *)leaf + sizeof(*lastlep) - 1));
}

/*
 * Log the header of the leaf1 or leafn block.
 */
void
xfs_dir2_leaf_log_header(
	xfs_trans_t		*tp,		/* transaction pointer */
	xfs_dabuf_t		*bp)		/* leaf buffer */
{
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */

	leaf = bp->data;
	ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC ||
	       be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
	xfs_da_log_buf(tp, bp, (uint)((char *)&leaf->hdr - (char *)leaf),
		(uint)(sizeof(leaf->hdr) - 1));
}

/*
 * Log the tail of the leaf1 block.
 */
STATIC void
xfs_dir2_leaf_log_tail(
	xfs_trans_t		*tp,		/* transaction pointer */
	xfs_dabuf_t		*bp)		/* leaf buffer */
{
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
	xfs_mount_t		*mp;		/* filesystem mount point */

	mp = tp->t_mountp;
	leaf = bp->data;
	ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAF1_MAGIC);
	ltp = xfs_dir2_leaf_tail_p(mp, leaf);
	xfs_da_log_buf(tp, bp, (uint)((char *)ltp - (char *)leaf),
		(uint)(mp->m_dirblksize - 1));
}

/*
 * Look up the entry referred to by args in the leaf format directory.
 * Most of the work is done by the xfs_dir2_leaf_lookup_int routine which
 * is also used by the node-format code.
 */
int
xfs_dir2_leaf_lookup(
	xfs_da_args_t		*args)		/* operation arguments */
{
	xfs_dabuf_t		*dbp;		/* data block buffer */
	xfs_dir2_data_entry_t	*dep;		/* data block entry */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			error;		/* error return code */
	int			index;		/* found entry index */
	xfs_dabuf_t		*lbp;		/* leaf buffer */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
	xfs_trans_t		*tp;		/* transaction pointer */

	xfs_dir2_trace_args("leaf_lookup", args);
	/*
	 * Look up name in the leaf block, returning both buffers and index.
	 */
	if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
		return error;
	}
	tp = args->trans;
	dp = args->dp;
	xfs_dir2_leaf_check(dp, lbp);
	leaf = lbp->data;
	/*
	 * Get to the leaf entry and contained data entry address.
	 */
	lep = &leaf->ents[index];
	/*
	 * Point to the data entry.
	 */
	dep = (xfs_dir2_data_entry_t *)
	      ((char *)dbp->data +
	       xfs_dir2_dataptr_to_off(dp->i_mount, be32_to_cpu(lep->address)));
	/*
	 * Return the found inode number.
	 */
	args->inumber = be64_to_cpu(dep->inumber);
	xfs_da_brelse(tp, dbp);
	xfs_da_brelse(tp, lbp);
	return XFS_ERROR(EEXIST);
}

/*
 * Look up name/hash in the leaf block.
 * Fill in indexp with the found index, and dbpp with the data buffer.
 * If not found dbpp will be NULL, and ENOENT comes back.
 * lbpp will always be filled in with the leaf buffer unless there's an error.
 */
static int					/* error */
xfs_dir2_leaf_lookup_int(
	xfs_da_args_t		*args,		/* operation arguments */
	xfs_dabuf_t		**lbpp,		/* out: leaf buffer */
	int			*indexp,	/* out: index in leaf block */
	xfs_dabuf_t		**dbpp)		/* out: data buffer */
{
	xfs_dir2_db_t		curdb;		/* current data block number */
	xfs_dabuf_t		*dbp;		/* data buffer */
	xfs_dir2_data_entry_t	*dep;		/* data entry */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			error;		/* error return code */
	int			index;		/* index in leaf block */
	xfs_dabuf_t		*lbp;		/* leaf buffer */
	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_mount_t		*mp;		/* filesystem mount point */
	xfs_dir2_db_t		newdb;		/* new data block number */
	xfs_trans_t		*tp;		/* transaction pointer */

	dp = args->dp;
	tp = args->trans;
	mp = dp->i_mount;
	/*
	 * Read the leaf block into the buffer.
	 */
	if ((error =
	    xfs_da_read_buf(tp, dp, mp->m_dirleafblk, -1, &lbp,
		    XFS_DATA_FORK))) {
		return error;
	}
	*lbpp = lbp;
	leaf = lbp->data;
	xfs_dir2_leaf_check(dp, lbp);
	/*
	 * Look for the first leaf entry with our hash value.
	 */
	index = xfs_dir2_leaf_search_hash(args, lbp);
	/*
	 * Loop over all the entries with the right hash value
	 * looking to match the name.
	 */
	for (lep = &leaf->ents[index], dbp = NULL, curdb = -1;
	     index < be16_to_cpu(leaf->hdr.count) && be32_to_cpu(lep->hashval) == args->hashval;
	     lep++, index++) {
		/*
		 * Skip over stale leaf entries.
		 */
		if (be32_to_cpu(lep->address) == XFS_DIR2_NULL_DATAPTR)
			continue;
		/*
		 * Get the new data block number.
		 */
		newdb = xfs_dir2_dataptr_to_db(mp, be32_to_cpu(lep->address));
		/*
		 * If it's not the same as the old data block number,
		 * need to pitch the old one and read the new one.
		 */
		if (newdb != curdb) {
			if (dbp)
				xfs_da_brelse(tp, dbp);
			if ((error =
			    xfs_da_read_buf(tp, dp,
				    xfs_dir2_db_to_da(mp, newdb), -1, &dbp,
				    XFS_DATA_FORK))) {
				xfs_da_brelse(tp, lbp);
				return error;
			}
			xfs_dir2_data_check(dp, dbp);
			curdb = newdb;
		}
		/*
		 * Point to the data entry.
		 */
		dep = (xfs_dir2_data_entry_t *)
		      ((char *)dbp->data +
		       xfs_dir2_dataptr_to_off(mp, be32_to_cpu(lep->address)));
		/*
		 * If it matches then return it.
		 */
		if (dep->namelen == args->namelen &&
		    dep->name[0] == args->name[0] &&
		    memcmp(dep->name, args->name, args->namelen) == 0) {
			*dbpp = dbp;
			*indexp = index;
			return 0;
		}
	}
	/*
	 * No match found, return ENOENT.
	 */
	ASSERT(args->oknoent);
	if (dbp)
		xfs_da_brelse(tp, dbp);
	xfs_da_brelse(tp, lbp);
	return XFS_ERROR(ENOENT);
}

/*
 * Remove an entry from a leaf format directory.
 */
int						/* error */
xfs_dir2_leaf_removename(
	xfs_da_args_t		*args)		/* operation arguments */
{
	__be16			*bestsp;	/* leaf block best freespace */
	xfs_dir2_data_t		*data;		/* data block structure */
	xfs_dir2_db_t		db;		/* data block number */
	xfs_dabuf_t		*dbp;		/* data block buffer */
	xfs_dir2_data_entry_t	*dep;		/* data entry structure */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			error;		/* error return code */
	xfs_dir2_db_t		i;		/* temporary data block # */
	int			index;		/* index into leaf entries */
	xfs_dabuf_t		*lbp;		/* leaf buffer */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
	xfs_mount_t		*mp;		/* filesystem mount point */
	int			needlog;	/* need to log data header */
	int			needscan;	/* need to rescan data frees */
	xfs_dir2_data_off_t	oldbest;	/* old value of best free */
	xfs_trans_t		*tp;		/* transaction pointer */

	xfs_dir2_trace_args("leaf_removename", args);
	/*
	 * Lookup the leaf entry, get the leaf and data blocks read in.
	 */
	if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
		return error;
	}
	dp = args->dp;
	tp = args->trans;
	mp = dp->i_mount;
	leaf = lbp->data;
	data = dbp->data;
	xfs_dir2_data_check(dp, dbp);
	/*
	 * Point to the leaf entry, use that to point to the data entry.
	 */
	lep = &leaf->ents[index];
	db = xfs_dir2_dataptr_to_db(mp, be32_to_cpu(lep->address));
	dep = (xfs_dir2_data_entry_t *)
	      ((char *)data + xfs_dir2_dataptr_to_off(mp, be32_to_cpu(lep->address)));
	needscan = needlog = 0;
	oldbest = be16_to_cpu(data->hdr.bestfree[0].length);
	ltp = xfs_dir2_leaf_tail_p(mp, leaf);
	bestsp = xfs_dir2_leaf_bests_p(ltp);
	ASSERT(be16_to_cpu(bestsp[db]) == oldbest);
	/*
	 * Mark the former data entry unused.
	 */
	xfs_dir2_data_make_free(tp, dbp,
		(xfs_dir2_data_aoff_t)((char *)dep - (char *)data),
		xfs_dir2_data_entsize(dep->namelen), &needlog, &needscan);
	/*
	 * We just mark the leaf entry stale by putting a null in it.
	 */
	be16_add(&leaf->hdr.stale, 1);
	xfs_dir2_leaf_log_header(tp, lbp);
	lep->address = cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
	xfs_dir2_leaf_log_ents(tp, lbp, index, index);
	/*
	 * Scan the freespace in the data block again if necessary,
	 * log the data block header if necessary.
	 */
	if (needscan)
		xfs_dir2_data_freescan(mp, data, &needlog);
	if (needlog)
		xfs_dir2_data_log_header(tp, dbp);
	/*
	 * If the longest freespace in the data block has changed,
	 * put the new value in the bests table and log that.
	 */
	if (be16_to_cpu(data->hdr.bestfree[0].length) != oldbest) {
		bestsp[db] = data->hdr.bestfree[0].length;
		xfs_dir2_leaf_log_bests(tp, lbp, db, db);
	}
	xfs_dir2_data_check(dp, dbp);
	/*
	 * If the data block is now empty then get rid of the data block.
	 */
	if (be16_to_cpu(data->hdr.bestfree[0].length) ==
	    mp->m_dirblksize - (uint)sizeof(data->hdr)) {
		ASSERT(db != mp->m_dirdatablk);
		if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
			/*
			 * Nope, can't get rid of it because it caused
			 * allocation of a bmap btree block to do so.
			 * Just go on, returning success, leaving the
			 * empty block in place.
			 */
			if (error == ENOSPC && args->total == 0) {
				xfs_da_buf_done(dbp);
				error = 0;
			}
			xfs_dir2_leaf_check(dp, lbp);
			xfs_da_buf_done(lbp);
			return error;
		}
		dbp = NULL;
		/*
		 * If this is the last data block then compact the
		 * bests table by getting rid of entries.
		 */
		if (db == be32_to_cpu(ltp->bestcount) - 1) {
			/*
			 * Look for the last active entry (i).
			 */
			for (i = db - 1; i > 0; i--) {
				if (be16_to_cpu(bestsp[i]) != NULLDATAOFF)
					break;
			}
			/*
			 * Copy the table down so inactive entries at the
			 * end are removed.
			 */
			memmove(&bestsp[db - i], bestsp,
				(be32_to_cpu(ltp->bestcount) - (db - i)) * sizeof(*bestsp));
			be32_add(&ltp->bestcount, -(db - i));
			xfs_dir2_leaf_log_tail(tp, lbp);
			xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
		} else
			bestsp[db] = cpu_to_be16(NULLDATAOFF);
	}
	/*
	 * If the data block was not the first one, drop it.
	 */
	else if (db != mp->m_dirdatablk && dbp != NULL) {
		xfs_da_buf_done(dbp);
		dbp = NULL;
	}
	xfs_dir2_leaf_check(dp, lbp);
	/*
	 * See if we can convert to block form.
	 */
	return xfs_dir2_leaf_to_block(args, lbp, dbp);
}

/*
 * Replace the inode number in a leaf format directory entry.
 */
int						/* error */
xfs_dir2_leaf_replace(
	xfs_da_args_t		*args)		/* operation arguments */
{
	xfs_dabuf_t		*dbp;		/* data block buffer */
	xfs_dir2_data_entry_t	*dep;		/* data block entry */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			error;		/* error return code */
	int			index;		/* index of leaf entry */
	xfs_dabuf_t		*lbp;		/* leaf buffer */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
	xfs_trans_t		*tp;		/* transaction pointer */

	xfs_dir2_trace_args("leaf_replace", args);
	/*
	 * Look up the entry.
	 */
	if ((error = xfs_dir2_leaf_lookup_int(args, &lbp, &index, &dbp))) {
		return error;
	}
	dp = args->dp;
	leaf = lbp->data;
	/*
	 * Point to the leaf entry, get data address from it.
	 */
	lep = &leaf->ents[index];
	/*
	 * Point to the data entry.
	 */
	dep = (xfs_dir2_data_entry_t *)
	      ((char *)dbp->data +
	       xfs_dir2_dataptr_to_off(dp->i_mount, be32_to_cpu(lep->address)));
	ASSERT(args->inumber != be64_to_cpu(dep->inumber));
	/*
	 * Put the new inode number in, log it.
	 */
	dep->inumber = cpu_to_be64(args->inumber);
	tp = args->trans;
	xfs_dir2_data_log_entry(tp, dbp, dep);
	xfs_da_buf_done(dbp);
	xfs_dir2_leaf_check(dp, lbp);
	xfs_da_brelse(tp, lbp);
	return 0;
}

/*
 * Return index in the leaf block (lbp) which is either the first
 * one with this hash value, or if there are none, the insert point
 * for that hash value.
 */
int						/* index value */
xfs_dir2_leaf_search_hash(
	xfs_da_args_t		*args,		/* operation arguments */
	xfs_dabuf_t		*lbp)		/* leaf buffer */
{
	xfs_dahash_t		hash=0;		/* hash from this entry */
	xfs_dahash_t		hashwant;	/* hash value looking for */
	int			high;		/* high leaf index */
	int			low;		/* low leaf index */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_entry_t	*lep;		/* leaf entry */
	int			mid=0;		/* current leaf index */

	leaf = lbp->data;
#ifndef __KERNEL__
	if (!leaf->hdr.count)
		return 0;
#endif
	/*
	 * Note, the table cannot be empty, so we have to go through the loop.
	 * Binary search the leaf entries looking for our hash value.
	 */
	for (lep = leaf->ents, low = 0, high = be16_to_cpu(leaf->hdr.count) - 1,
		hashwant = args->hashval;
	     low <= high; ) {
		mid = (low + high) >> 1;
		if ((hash = be32_to_cpu(lep[mid].hashval)) == hashwant)
			break;
		if (hash < hashwant)
			low = mid + 1;
		else
			high = mid - 1;
	}
	/*
	 * Found one, back up through all the equal hash values.
	 */
	if (hash == hashwant) {
		while (mid > 0 && be32_to_cpu(lep[mid - 1].hashval) == hashwant) {
			mid--;
		}
	}
	/*
	 * Need to point to an entry higher than ours.
	 */
	else if (hash < hashwant)
		mid++;
	return mid;
}

/*
 * Trim off a trailing data block.  We know it's empty since the leaf
 * freespace table says so.
 */
int						/* error */
xfs_dir2_leaf_trim_data(
	xfs_da_args_t		*args,		/* operation arguments */
	xfs_dabuf_t		*lbp,		/* leaf buffer */
	xfs_dir2_db_t		db)		/* data block number */
{
	__be16			*bestsp;	/* leaf bests table */
#ifdef DEBUG
	xfs_dir2_data_t		*data;		/* data block structure */
#endif
	xfs_dabuf_t		*dbp;		/* data block buffer */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			error;		/* error return value */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_dir2_leaf_tail_t	*ltp;		/* leaf tail structure */
	xfs_mount_t		*mp;		/* filesystem mount point */
	xfs_trans_t		*tp;		/* transaction pointer */

	dp = args->dp;
	mp = dp->i_mount;
	tp = args->trans;
	/*
	 * Read the offending data block.  We need its buffer.
	 */
	if ((error = xfs_da_read_buf(tp, dp, xfs_dir2_db_to_da(mp, db), -1, &dbp,
			XFS_DATA_FORK))) {
		return error;
	}
#ifdef DEBUG
	data = dbp->data;
	ASSERT(be32_to_cpu(data->hdr.magic) == XFS_DIR2_DATA_MAGIC);
#endif
	/* this seems to be an error
	 * data is only valid if DEBUG is defined?
	 * RMC 09/08/1999
	 */

	leaf = lbp->data;
	ltp = xfs_dir2_leaf_tail_p(mp, leaf);
	ASSERT(be16_to_cpu(data->hdr.bestfree[0].length) ==
	       mp->m_dirblksize - (uint)sizeof(data->hdr));
	ASSERT(db == be32_to_cpu(ltp->bestcount) - 1);
	/*
	 * Get rid of the data block.
	 */
	if ((error = xfs_dir2_shrink_inode(args, db, dbp))) {
		ASSERT(error != ENOSPC);
		xfs_da_brelse(tp, dbp);
		return error;
	}
	/*
	 * Eliminate the last bests entry from the table.
	 */
	bestsp = xfs_dir2_leaf_bests_p(ltp);
	be32_add(&ltp->bestcount, -1);
	memmove(&bestsp[1], &bestsp[0], be32_to_cpu(ltp->bestcount) * sizeof(*bestsp));
	xfs_dir2_leaf_log_tail(tp, lbp);
	xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
	return 0;
}

/*
 * Convert node form directory to leaf form directory.
 * The root of the node form dir needs to already be a LEAFN block.
 * Just return if we can't do anything.
 */
int						/* error */
xfs_dir2_node_to_leaf(
	xfs_da_state_t		*state)		/* directory operation state */
{
	xfs_da_args_t		*args;		/* operation arguments */
	xfs_inode_t		*dp;		/* incore directory inode */
	int			error;		/* error return code */
	xfs_dabuf_t		*fbp;		/* buffer for freespace block */
	xfs_fileoff_t		fo;		/* freespace file offset */
	xfs_dir2_free_t		*free;		/* freespace structure */
	xfs_dabuf_t		*lbp;		/* buffer for leaf block */
	xfs_dir2_leaf_tail_t	*ltp;		/* tail of leaf structure */
	xfs_dir2_leaf_t		*leaf;		/* leaf structure */
	xfs_mount_t		*mp;		/* filesystem mount point */
	int			rval;		/* successful free trim? */
	xfs_trans_t		*tp;		/* transaction pointer */

	/*
	 * There's more than a leaf level in the btree, so there must
	 * be multiple leafn blocks.  Give up.
	 */
	if (state->path.active > 1)
		return 0;
	args = state->args;
	xfs_dir2_trace_args("node_to_leaf", args);
	mp = state->mp;
	dp = args->dp;
	tp = args->trans;
	/*
	 * Get the last offset in the file.
	 */
	if ((error = xfs_bmap_last_offset(tp, dp, &fo, XFS_DATA_FORK))) {
		return error;
	}
	fo -= mp->m_dirblkfsbs;
	/*
	 * If there are freespace blocks other than the first one,
	 * take this opportunity to remove trailing empty freespace blocks
	 * that may have been left behind during no-space-reservation
	 * operations.
	 */
	while (fo > mp->m_dirfreeblk) {
		if ((error = xfs_dir2_node_trim_free(args, fo, &rval))) {
			return error;
		}
		if (rval)
			fo -= mp->m_dirblkfsbs;
		else
			return 0;
	}
	/*
	 * Now find the block just before the freespace block.
	 */
	if ((error = xfs_bmap_last_before(tp, dp, &fo, XFS_DATA_FORK))) {
		return error;
	}
	/*
	 * If it's not the single leaf block, give up.
	 */
	if (XFS_FSB_TO_B(mp, fo) > XFS_DIR2_LEAF_OFFSET + mp->m_dirblksize)
		return 0;
	lbp = state->path.blk[0].bp;
	leaf = lbp->data;
	ASSERT(be16_to_cpu(leaf->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
	/*
	 * Read the freespace block.
	 */
	if ((error = xfs_da_read_buf(tp, dp, mp->m_dirfreeblk, -1, &fbp,
			XFS_DATA_FORK))) {
		return error;
	}
	free = fbp->data;
	ASSERT(be32_to_cpu(free->hdr.magic) == XFS_DIR2_FREE_MAGIC);
	ASSERT(!free->hdr.firstdb);
	/*
	 * Now see if the leafn and free data will fit in a leaf1.
	 * If not, release the buffer and give up.
	 */
	if ((uint)sizeof(leaf->hdr) +
	    (be16_to_cpu(leaf->hdr.count) - be16_to_cpu(leaf->hdr.stale)) * (uint)sizeof(leaf->ents[0]) +
	    be32_to_cpu(free->hdr.nvalid) * (uint)sizeof(leaf->bests[0]) +
	    (uint)sizeof(leaf->tail) >
	    mp->m_dirblksize) {
		xfs_da_brelse(tp, fbp);
		return 0;
	}
	/*
	 * If the leaf has any stale entries in it, compress them out.
	 * The compact routine will log the header.
	 */
	if (be16_to_cpu(leaf->hdr.stale))
		xfs_dir2_leaf_compact(args, lbp);
	else
		xfs_dir2_leaf_log_header(tp, lbp);
	leaf->hdr.info.magic = cpu_to_be16(XFS_DIR2_LEAF1_MAGIC);
	/*
	 * Set up the leaf tail from the freespace block.
	 */
	ltp = xfs_dir2_leaf_tail_p(mp, leaf);
	ltp->bestcount = free->hdr.nvalid;
	/*
	 * Set up the leaf bests table.
	 */
	memcpy(xfs_dir2_leaf_bests_p(ltp), free->bests,
		be32_to_cpu(ltp->bestcount) * sizeof(leaf->bests[0]));
	xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);
	xfs_dir2_leaf_log_tail(tp, lbp);
	xfs_dir2_leaf_check(dp, lbp);
	/*
	 * Get rid of the freespace block.
	 */
	error = xfs_dir2_shrink_inode(args, XFS_DIR2_FREE_FIRSTDB(mp), fbp);
	if (error) {
		/*
		 * This can't fail here because it can only happen when
		 * punching out the middle of an extent, and this is an
		 * isolated block.
		 */
		ASSERT(error != ENOSPC);
		return error;
	}
	fbp = NULL;
	/*
	 * Now see if we can convert the single-leaf directory
	 * down to a block form directory.
	 * This routine always kills the dabuf for the leaf, so
	 * eliminate it from the path.
	 */
	error = xfs_dir2_leaf_to_block(args, lbp, NULL);
	state->path.blk[0].bp = NULL;
	return error;
}