Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 2648 insertions, 0 deletions

diff --git a/fs/xfs/xfs_da_btree.c b/fs/xfs/xfs_da_btree.c
new file mode 100644
index 000000000000..d7fe28866764
--- /dev/null
+++ b/fs/xfs/xfs_da_btree.c
@@ -0,0 +1,2648 @@
+/*
+ * Copyright (c) 2000-2004 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/
+ */
+
+#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_ag.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_attr.h"
+#include "xfs_attr_leaf.h"
+#include "xfs_dir_leaf.h"
+#include "xfs_dir2_data.h"
+#include "xfs_dir2_leaf.h"
+#include "xfs_dir2_block.h"
+#include "xfs_dir2_node.h"
+#include "xfs_error.h"
+#include "xfs_bit.h"
+
+/*
+ * xfs_da_btree.c
+ *
+ * Routines to implement directories as Btrees of hashed names.
+ */
+
+/*========================================================================
+ * Function prototypes for the kernel.
+ *========================================================================*/
+
+/*
+ * Routines used for growing the Btree.
+ */
+STATIC int xfs_da_root_split(xfs_da_state_t *state,
+					    xfs_da_state_blk_t *existing_root,
+					    xfs_da_state_blk_t *new_child);
+STATIC int xfs_da_node_split(xfs_da_state_t *state,
+					    xfs_da_state_blk_t *existing_blk,
+					    xfs_da_state_blk_t *split_blk,
+					    xfs_da_state_blk_t *blk_to_add,
+					    int treelevel,
+					    int *result);
+STATIC void xfs_da_node_rebalance(xfs_da_state_t *state,
+					 xfs_da_state_blk_t *node_blk_1,
+					 xfs_da_state_blk_t *node_blk_2);
+STATIC void xfs_da_node_add(xfs_da_state_t *state,
+				   xfs_da_state_blk_t *old_node_blk,
+				   xfs_da_state_blk_t *new_node_blk);
+
+/*
+ * Routines used for shrinking the Btree.
+ */
+STATIC int xfs_da_root_join(xfs_da_state_t *state,
+					   xfs_da_state_blk_t *root_blk);
+STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval);
+STATIC void xfs_da_node_remove(xfs_da_state_t *state,
+					      xfs_da_state_blk_t *drop_blk);
+STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
+					 xfs_da_state_blk_t *src_node_blk,
+					 xfs_da_state_blk_t *dst_node_blk);
+
+/*
+ * Utility routines.
+ */
+STATIC uint	xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count);
+STATIC int	xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp);
+STATIC xfs_dabuf_t *xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra);
+
+
+/*========================================================================
+ * Routines used for growing the Btree.
+ *========================================================================*/
+
+/*
+ * Create the initial contents of an intermediate node.
+ */
+int
+xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
+				 xfs_dabuf_t **bpp, int whichfork)
+{
+	xfs_da_intnode_t *node;
+	xfs_dabuf_t *bp;
+	int error;
+	xfs_trans_t *tp;
+
+	tp = args->trans;
+	error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork);
+	if (error)
+		return(error);
+	ASSERT(bp != NULL);
+	node = bp->data;
+	node->hdr.info.forw = 0;
+	node->hdr.info.back = 0;
+	INT_SET(node->hdr.info.magic, ARCH_CONVERT, XFS_DA_NODE_MAGIC);
+	node->hdr.info.pad = 0;
+	node->hdr.count = 0;
+	INT_SET(node->hdr.level, ARCH_CONVERT, level);
+
+	xfs_da_log_buf(tp, bp,
+		XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
+
+	*bpp = bp;
+	return(0);
+}
+
+/*
+ * Split a leaf node, rebalance, then possibly split
+ * intermediate nodes, rebalance, etc.
+ */
+int							/* error */
+xfs_da_split(xfs_da_state_t *state)
+{
+	xfs_da_state_blk_t *oldblk, *newblk, *addblk;
+	xfs_da_intnode_t *node;
+	xfs_dabuf_t *bp;
+	int max, action, error, i;
+
+	/*
+	 * Walk back up the tree splitting/inserting/adjusting as necessary.
+	 * If we need to insert and there isn't room, split the node, then
+	 * decide which fragment to insert the new block from below into.
+	 * Note that we may split the root this way, but we need more fixup.
+	 */
+	max = state->path.active - 1;
+	ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
+	ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
+	       state->path.blk[max].magic == XFS_DIRX_LEAF_MAGIC(state->mp));
+
+	addblk = &state->path.blk[max];		/* initial dummy value */
+	for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
+		oldblk = &state->path.blk[i];
+		newblk = &state->altpath.blk[i];
+
+		/*
+		 * If a leaf node then
+		 *     Allocate a new leaf node, then rebalance across them.
+		 * else if an intermediate node then
+		 *     We split on the last layer, must we split the node?
+		 */
+		switch (oldblk->magic) {
+		case XFS_ATTR_LEAF_MAGIC:
+#ifndef __KERNEL__
+			return(ENOTTY);
+#else
+			error = xfs_attr_leaf_split(state, oldblk, newblk);
+			if ((error != 0) && (error != ENOSPC)) {
+				return(error);	/* GROT: attr is inconsistent */
+			}
+			if (!error) {
+				addblk = newblk;
+				break;
+			}
+			/*
+			 * Entry wouldn't fit, split the leaf again.
+			 */
+			state->extravalid = 1;
+			if (state->inleaf) {
+				state->extraafter = 0;	/* before newblk */
+				error = xfs_attr_leaf_split(state, oldblk,
+							    &state->extrablk);
+			} else {
+				state->extraafter = 1;	/* after newblk */
+				error = xfs_attr_leaf_split(state, newblk,
+							    &state->extrablk);
+			}
+			if (error)
+				return(error);	/* GROT: attr inconsistent */
+			addblk = newblk;
+			break;
+#endif
+		case XFS_DIR_LEAF_MAGIC:
+			ASSERT(XFS_DIR_IS_V1(state->mp));
+			error = xfs_dir_leaf_split(state, oldblk, newblk);
+			if ((error != 0) && (error != ENOSPC)) {
+				return(error);	/* GROT: dir is inconsistent */
+			}
+			if (!error) {
+				addblk = newblk;
+				break;
+			}
+			/*
+			 * Entry wouldn't fit, split the leaf again.
+			 */
+			state->extravalid = 1;
+			if (state->inleaf) {
+				state->extraafter = 0;	/* before newblk */
+				error = xfs_dir_leaf_split(state, oldblk,
+							   &state->extrablk);
+				if (error)
+					return(error);	/* GROT: dir incon. */
+				addblk = newblk;
+			} else {
+				state->extraafter = 1;	/* after newblk */
+				error = xfs_dir_leaf_split(state, newblk,
+							   &state->extrablk);
+				if (error)
+					return(error);	/* GROT: dir incon. */
+				addblk = newblk;
+			}
+			break;
+		case XFS_DIR2_LEAFN_MAGIC:
+			ASSERT(XFS_DIR_IS_V2(state->mp));
+			error = xfs_dir2_leafn_split(state, oldblk, newblk);
+			if (error)
+				return error;
+			addblk = newblk;
+			break;
+		case XFS_DA_NODE_MAGIC:
+			error = xfs_da_node_split(state, oldblk, newblk, addblk,
+							 max - i, &action);
+			xfs_da_buf_done(addblk->bp);
+			addblk->bp = NULL;
+			if (error)
+				return(error);	/* GROT: dir is inconsistent */
+			/*
+			 * Record the newly split block for the next time thru?
+			 */
+			if (action)
+				addblk = newblk;
+			else
+				addblk = NULL;
+			break;
+		}
+
+		/*
+		 * Update the btree to show the new hashval for this child.
+		 */
+		xfs_da_fixhashpath(state, &state->path);
+		/*
+		 * If we won't need this block again, it's getting dropped
+		 * from the active path by the loop control, so we need
+		 * to mark it done now.
+		 */
+		if (i > 0 || !addblk)
+			xfs_da_buf_done(oldblk->bp);
+	}
+	if (!addblk)
+		return(0);
+
+	/*
+	 * Split the root node.
+	 */
+	ASSERT(state->path.active == 0);
+	oldblk = &state->path.blk[0];
+	error = xfs_da_root_split(state, oldblk, addblk);
+	if (error) {
+		xfs_da_buf_done(oldblk->bp);
+		xfs_da_buf_done(addblk->bp);
+		addblk->bp = NULL;
+		return(error);	/* GROT: dir is inconsistent */
+	}
+
+	/*
+	 * Update pointers to the node which used to be block 0 and
+	 * just got bumped because of the addition of a new root node.
+	 * There might be three blocks involved if a double split occurred,
+	 * and the original block 0 could be at any position in the list.
+	 */
+
+	node = oldblk->bp->data;
+	if (node->hdr.info.forw) {
+		if (INT_GET(node->hdr.info.forw, ARCH_CONVERT) == addblk->blkno) {
+			bp = addblk->bp;
+		} else {
+			ASSERT(state->extravalid);
+			bp = state->extrablk.bp;
+		}
+		node = bp->data;
+		INT_SET(node->hdr.info.back, ARCH_CONVERT, oldblk->blkno);
+		xfs_da_log_buf(state->args->trans, bp,
+		    XFS_DA_LOGRANGE(node, &node->hdr.info,
+		    sizeof(node->hdr.info)));
+	}
+	node = oldblk->bp->data;
+	if (INT_GET(node->hdr.info.back, ARCH_CONVERT)) {
+		if (INT_GET(node->hdr.info.back, ARCH_CONVERT) == addblk->blkno) {
+			bp = addblk->bp;
+		} else {
+			ASSERT(state->extravalid);
+			bp = state->extrablk.bp;
+		}
+		node = bp->data;
+		INT_SET(node->hdr.info.forw, ARCH_CONVERT, oldblk->blkno);
+		xfs_da_log_buf(state->args->trans, bp,
+		    XFS_DA_LOGRANGE(node, &node->hdr.info,
+		    sizeof(node->hdr.info)));
+	}
+	xfs_da_buf_done(oldblk->bp);
+	xfs_da_buf_done(addblk->bp);
+	addblk->bp = NULL;
+	return(0);
+}
+
+/*
+ * Split the root.  We have to create a new root and point to the two
+ * parts (the split old root) that we just created.  Copy block zero to
+ * the EOF, extending the inode in process.
+ */
+STATIC int						/* error */
+xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
+				 xfs_da_state_blk_t *blk2)
+{
+	xfs_da_intnode_t *node, *oldroot;
+	xfs_da_args_t *args;
+	xfs_dablk_t blkno;
+	xfs_dabuf_t *bp;
+	int error, size;
+	xfs_inode_t *dp;
+	xfs_trans_t *tp;
+	xfs_mount_t *mp;
+	xfs_dir2_leaf_t *leaf;
+
+	/*
+	 * Copy the existing (incorrect) block from the root node position
+	 * to a free space somewhere.
+	 */
+	args = state->args;
+	ASSERT(args != NULL);
+	error = xfs_da_grow_inode(args, &blkno);
+	if (error)
+		return(error);
+	dp = args->dp;
+	tp = args->trans;
+	mp = state->mp;
+	error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
+	if (error)
+		return(error);
+	ASSERT(bp != NULL);
+	node = bp->data;
+	oldroot = blk1->bp->data;
+	if (INT_GET(oldroot->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC) {
+		size = (int)((char *)&oldroot->btree[INT_GET(oldroot->hdr.count, ARCH_CONVERT)] -
+			     (char *)oldroot);
+	} else {
+		ASSERT(XFS_DIR_IS_V2(mp));
+		ASSERT(INT_GET(oldroot->hdr.info.magic, ARCH_CONVERT) == XFS_DIR2_LEAFN_MAGIC);
+		leaf = (xfs_dir2_leaf_t *)oldroot;
+		size = (int)((char *)&leaf->ents[INT_GET(leaf->hdr.count, ARCH_CONVERT)] -
+			     (char *)leaf);
+	}
+	memcpy(node, oldroot, size);
+	xfs_da_log_buf(tp, bp, 0, size - 1);
+	xfs_da_buf_done(blk1->bp);
+	blk1->bp = bp;
+	blk1->blkno = blkno;
+
+	/*
+	 * Set up the new root node.
+	 */
+	error = xfs_da_node_create(args,
+		args->whichfork == XFS_DATA_FORK &&
+		XFS_DIR_IS_V2(mp) ? mp->m_dirleafblk : 0,
+		INT_GET(node->hdr.level, ARCH_CONVERT) + 1, &bp, args->whichfork);
+	if (error)
+		return(error);
+	node = bp->data;
+	INT_SET(node->btree[0].hashval, ARCH_CONVERT, blk1->hashval);
+	INT_SET(node->btree[0].before, ARCH_CONVERT, blk1->blkno);
+	INT_SET(node->btree[1].hashval, ARCH_CONVERT, blk2->hashval);
+	INT_SET(node->btree[1].before, ARCH_CONVERT, blk2->blkno);
+	INT_SET(node->hdr.count, ARCH_CONVERT, 2);
+
+#ifdef DEBUG
+	if (INT_GET(oldroot->hdr.info.magic, ARCH_CONVERT) == XFS_DIR2_LEAFN_MAGIC) {
+		ASSERT(blk1->blkno >= mp->m_dirleafblk &&
+		       blk1->blkno < mp->m_dirfreeblk);
+		ASSERT(blk2->blkno >= mp->m_dirleafblk &&
+		       blk2->blkno < mp->m_dirfreeblk);
+	}
+#endif
+
+	/* Header is already logged by xfs_da_node_create */
+	xfs_da_log_buf(tp, bp,
+		XFS_DA_LOGRANGE(node, node->btree,
+			sizeof(xfs_da_node_entry_t) * 2));
+	xfs_da_buf_done(bp);
+
+	return(0);
+}
+
+/*
+ * Split the node, rebalance, then add the new entry.
+ */
+STATIC int						/* error */
+xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
+				 xfs_da_state_blk_t *newblk,
+				 xfs_da_state_blk_t *addblk,
+				 int treelevel, int *result)
+{
+	xfs_da_intnode_t *node;
+	xfs_dablk_t blkno;
+	int newcount, error;
+	int useextra;
+
+	node = oldblk->bp->data;
+	ASSERT(INT_GET(node->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+
+	/*
+	 * With V2 the extra block is data or freespace.
+	 */
+	useextra = state->extravalid && XFS_DIR_IS_V1(state->mp);
+	newcount = 1 + useextra;
+	/*
+	 * Do we have to split the node?
+	 */
+	if ((INT_GET(node->hdr.count, ARCH_CONVERT) + newcount) > state->node_ents) {
+		/*
+		 * Allocate a new node, add to the doubly linked chain of
+		 * nodes, then move some of our excess entries into it.
+		 */
+		error = xfs_da_grow_inode(state->args, &blkno);
+		if (error)
+			return(error);	/* GROT: dir is inconsistent */
+
+		error = xfs_da_node_create(state->args, blkno, treelevel,
+					   &newblk->bp, state->args->whichfork);
+		if (error)
+			return(error);	/* GROT: dir is inconsistent */
+		newblk->blkno = blkno;
+		newblk->magic = XFS_DA_NODE_MAGIC;
+		xfs_da_node_rebalance(state, oldblk, newblk);
+		error = xfs_da_blk_link(state, oldblk, newblk);
+		if (error)
+			return(error);
+		*result = 1;
+	} else {
+		*result = 0;
+	}
+
+	/*
+	 * Insert the new entry(s) into the correct block
+	 * (updating last hashval in the process).
+	 *
+	 * xfs_da_node_add() inserts BEFORE the given index,
+	 * and as a result of using node_lookup_int() we always
+	 * point to a valid entry (not after one), but a split
+	 * operation always results in a new block whose hashvals
+	 * FOLLOW the current block.
+	 *
+	 * If we had double-split op below us, then add the extra block too.
+	 */
+	node = oldblk->bp->data;
+	if (oldblk->index <= INT_GET(node->hdr.count, ARCH_CONVERT)) {
+		oldblk->index++;
+		xfs_da_node_add(state, oldblk, addblk);
+		if (useextra) {
+			if (state->extraafter)
+				oldblk->index++;
+			xfs_da_node_add(state, oldblk, &state->extrablk);
+			state->extravalid = 0;
+		}
+	} else {
+		newblk->index++;
+		xfs_da_node_add(state, newblk, addblk);
+		if (useextra) {
+			if (state->extraafter)
+				newblk->index++;
+			xfs_da_node_add(state, newblk, &state->extrablk);
+			state->extravalid = 0;
+		}
+	}
+
+	return(0);
+}
+
+/*
+ * Balance the btree elements between two intermediate nodes,
+ * usually one full and one empty.
+ *
+ * NOTE: if blk2 is empty, then it will get the upper half of blk1.
+ */
+STATIC void
+xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
+				     xfs_da_state_blk_t *blk2)
+{
+	xfs_da_intnode_t *node1, *node2, *tmpnode;
+	xfs_da_node_entry_t *btree_s, *btree_d;
+	int count, tmp;
+	xfs_trans_t *tp;
+
+	node1 = blk1->bp->data;
+	node2 = blk2->bp->data;
+	/*
+	 * Figure out how many entries need to move, and in which direction.
+	 * Swap the nodes around if that makes it simpler.
+	 */
+	if ((INT_GET(node1->hdr.count, ARCH_CONVERT) > 0) && (INT_GET(node2->hdr.count, ARCH_CONVERT) > 0) &&
+	    ((INT_GET(node2->btree[ 0 ].hashval, ARCH_CONVERT) < INT_GET(node1->btree[ 0 ].hashval, ARCH_CONVERT)) ||
+	     (INT_GET(node2->btree[ INT_GET(node2->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT) <
+	      INT_GET(node1->btree[ INT_GET(node1->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT)))) {
+		tmpnode = node1;
+		node1 = node2;
+		node2 = tmpnode;
+	}
+	ASSERT(INT_GET(node1->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+	ASSERT(INT_GET(node2->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+	count = (INT_GET(node1->hdr.count, ARCH_CONVERT) - INT_GET(node2->hdr.count, ARCH_CONVERT)) / 2;
+	if (count == 0)
+		return;
+	tp = state->args->trans;
+	/*
+	 * Two cases: high-to-low and low-to-high.
+	 */
+	if (count > 0) {
+		/*
+		 * Move elements in node2 up to make a hole.
+		 */
+		if ((tmp = INT_GET(node2->hdr.count, ARCH_CONVERT)) > 0) {
+			tmp *= (uint)sizeof(xfs_da_node_entry_t);
+			btree_s = &node2->btree[0];
+			btree_d = &node2->btree[count];
+			memmove(btree_d, btree_s, tmp);
+		}
+
+		/*
+		 * Move the req'd B-tree elements from high in node1 to
+		 * low in node2.
+		 */
+		INT_MOD(node2->hdr.count, ARCH_CONVERT, count);
+		tmp = count * (uint)sizeof(xfs_da_node_entry_t);
+		btree_s = &node1->btree[INT_GET(node1->hdr.count, ARCH_CONVERT) - count];
+		btree_d = &node2->btree[0];
+		memcpy(btree_d, btree_s, tmp);
+		INT_MOD(node1->hdr.count, ARCH_CONVERT, -(count));
+
+	} else {
+		/*
+		 * Move the req'd B-tree elements from low in node2 to
+		 * high in node1.
+		 */
+		count = -count;
+		tmp = count * (uint)sizeof(xfs_da_node_entry_t);
+		btree_s = &node2->btree[0];
+		btree_d = &node1->btree[INT_GET(node1->hdr.count, ARCH_CONVERT)];
+		memcpy(btree_d, btree_s, tmp);
+		INT_MOD(node1->hdr.count, ARCH_CONVERT, count);
+		xfs_da_log_buf(tp, blk1->bp,
+			XFS_DA_LOGRANGE(node1, btree_d, tmp));
+
+		/*
+		 * Move elements in node2 down to fill the hole.
+		 */
+		tmp  = INT_GET(node2->hdr.count, ARCH_CONVERT) - count;
+		tmp *= (uint)sizeof(xfs_da_node_entry_t);
+		btree_s = &node2->btree[count];
+		btree_d = &node2->btree[0];
+		memmove(btree_d, btree_s, tmp);
+		INT_MOD(node2->hdr.count, ARCH_CONVERT, -(count));
+	}
+
+	/*
+	 * Log header of node 1 and all current bits of node 2.
+	 */
+	xfs_da_log_buf(tp, blk1->bp,
+		XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr)));
+	xfs_da_log_buf(tp, blk2->bp,
+		XFS_DA_LOGRANGE(node2, &node2->hdr,
+			sizeof(node2->hdr) +
+			sizeof(node2->btree[0]) * INT_GET(node2->hdr.count, ARCH_CONVERT)));
+
+	/*
+	 * Record the last hashval from each block for upward propagation.
+	 * (note: don't use the swapped node pointers)
+	 */
+	node1 = blk1->bp->data;
+	node2 = blk2->bp->data;
+	blk1->hashval = INT_GET(node1->btree[ INT_GET(node1->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
+	blk2->hashval = INT_GET(node2->btree[ INT_GET(node2->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
+
+	/*
+	 * Adjust the expected index for insertion.
+	 */
+	if (blk1->index >= INT_GET(node1->hdr.count, ARCH_CONVERT)) {
+		blk2->index = blk1->index - INT_GET(node1->hdr.count, ARCH_CONVERT);
+		blk1->index = INT_GET(node1->hdr.count, ARCH_CONVERT) + 1;	/* make it invalid */
+	}
+}
+
+/*
+ * Add a new entry to an intermediate node.
+ */
+STATIC void
+xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
+			       xfs_da_state_blk_t *newblk)
+{
+	xfs_da_intnode_t *node;
+	xfs_da_node_entry_t *btree;
+	int tmp;
+	xfs_mount_t *mp;
+
+	node = oldblk->bp->data;
+	mp = state->mp;
+	ASSERT(INT_GET(node->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+	ASSERT((oldblk->index >= 0) && (oldblk->index <= INT_GET(node->hdr.count, ARCH_CONVERT)));
+	ASSERT(newblk->blkno != 0);
+	if (state->args->whichfork == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
+		ASSERT(newblk->blkno >= mp->m_dirleafblk &&
+		       newblk->blkno < mp->m_dirfreeblk);
+
+	/*
+	 * We may need to make some room before we insert the new node.
+	 */
+	tmp = 0;
+	btree = &node->btree[ oldblk->index ];
+	if (oldblk->index < INT_GET(node->hdr.count, ARCH_CONVERT)) {
+		tmp = (INT_GET(node->hdr.count, ARCH_CONVERT) - oldblk->index) * (uint)sizeof(*btree);
+		memmove(btree + 1, btree, tmp);
+	}
+	INT_SET(btree->hashval, ARCH_CONVERT, newblk->hashval);
+	INT_SET(btree->before, ARCH_CONVERT, newblk->blkno);
+	xfs_da_log_buf(state->args->trans, oldblk->bp,
+		XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree)));
+	INT_MOD(node->hdr.count, ARCH_CONVERT, +1);
+	xfs_da_log_buf(state->args->trans, oldblk->bp,
+		XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
+
+	/*
+	 * Copy the last hash value from the oldblk to propagate upwards.
+	 */
+	oldblk->hashval = INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
+}
+
+/*========================================================================
+ * Routines used for shrinking the Btree.
+ *========================================================================*/
+
+/*
+ * Deallocate an empty leaf node, remove it from its parent,
+ * possibly deallocating that block, etc...
+ */
+int
+xfs_da_join(xfs_da_state_t *state)
+{
+	xfs_da_state_blk_t *drop_blk, *save_blk;
+	int action, error;
+
+	action = 0;
+	drop_blk = &state->path.blk[ state->path.active-1 ];
+	save_blk = &state->altpath.blk[ state->path.active-1 ];
+	ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
+	ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
+	       drop_blk->magic == XFS_DIRX_LEAF_MAGIC(state->mp));
+
+	/*
+	 * Walk back up the tree joining/deallocating as necessary.
+	 * When we stop dropping blocks, break out.
+	 */
+	for (  ; state->path.active >= 2; drop_blk--, save_blk--,
+		 state->path.active--) {
+		/*
+		 * See if we can combine the block with a neighbor.
+		 *   (action == 0) => no options, just leave
+		 *   (action == 1) => coalesce, then unlink
+		 *   (action == 2) => block empty, unlink it
+		 */
+		switch (drop_blk->magic) {
+		case XFS_ATTR_LEAF_MAGIC:
+#ifndef __KERNEL__
+			error = ENOTTY;
+#else
+			error = xfs_attr_leaf_toosmall(state, &action);
+#endif
+			if (error)
+				return(error);
+			if (action == 0)
+				return(0);
+#ifdef __KERNEL__
+			xfs_attr_leaf_unbalance(state, drop_blk, save_blk);
+#endif
+			break;
+		case XFS_DIR_LEAF_MAGIC:
+			ASSERT(XFS_DIR_IS_V1(state->mp));
+			error = xfs_dir_leaf_toosmall(state, &action);
+			if (error)
+				return(error);
+			if (action == 0)
+				return(0);
+			xfs_dir_leaf_unbalance(state, drop_blk, save_blk);
+			break;
+		case XFS_DIR2_LEAFN_MAGIC:
+			ASSERT(XFS_DIR_IS_V2(state->mp));
+			error = xfs_dir2_leafn_toosmall(state, &action);
+			if (error)
+				return error;
+			if (action == 0)
+				return 0;
+			xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
+			break;
+		case XFS_DA_NODE_MAGIC:
+			/*
+			 * Remove the offending node, fixup hashvals,
+			 * check for a toosmall neighbor.
+			 */
+			xfs_da_node_remove(state, drop_blk);
+			xfs_da_fixhashpath(state, &state->path);
+			error = xfs_da_node_toosmall(state, &action);
+			if (error)
+				return(error);
+			if (action == 0)
+				return 0;
+			xfs_da_node_unbalance(state, drop_blk, save_blk);
+			break;
+		}
+		xfs_da_fixhashpath(state, &state->altpath);
+		error = xfs_da_blk_unlink(state, drop_blk, save_blk);
+		xfs_da_state_kill_altpath(state);
+		if (error)
+			return(error);
+		error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
+							 drop_blk->bp);
+		drop_blk->bp = NULL;
+		if (error)
+			return(error);
+	}
+	/*
+	 * We joined all the way to the top.  If it turns out that
+	 * we only have one entry in the root, make the child block
+	 * the new root.
+	 */
+	xfs_da_node_remove(state, drop_blk);
+	xfs_da_fixhashpath(state, &state->path);
+	error = xfs_da_root_join(state, &state->path.blk[0]);
+	return(error);
+}
+
+/*
+ * We have only one entry in the root.  Copy the only remaining child of
+ * the old root to block 0 as the new root node.
+ */
+STATIC int
+xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk)
+{
+	xfs_da_intnode_t *oldroot;
+	/* REFERENCED */
+	xfs_da_blkinfo_t *blkinfo;
+	xfs_da_args_t *args;
+	xfs_dablk_t child;
+	xfs_dabuf_t *bp;
+	int error;
+
+	args = state->args;
+	ASSERT(args != NULL);
+	ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
+	oldroot = root_blk->bp->data;
+	ASSERT(INT_GET(oldroot->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+	ASSERT(!oldroot->hdr.info.forw);
+	ASSERT(!oldroot->hdr.info.back);
+
+	/*
+	 * If the root has more than one child, then don't do anything.
+	 */
+	if (INT_GET(oldroot->hdr.count, ARCH_CONVERT) > 1)
+		return(0);
+
+	/*
+	 * Read in the (only) child block, then copy those bytes into
+	 * the root block's buffer and free the original child block.
+	 */
+	child = INT_GET(oldroot->btree[ 0 ].before, ARCH_CONVERT);
+	ASSERT(child != 0);
+	error = xfs_da_read_buf(args->trans, args->dp, child, -1, &bp,
+					     args->whichfork);
+	if (error)
+		return(error);
+	ASSERT(bp != NULL);
+	blkinfo = bp->data;
+	if (INT_GET(oldroot->hdr.level, ARCH_CONVERT) == 1) {
+		ASSERT(INT_GET(blkinfo->magic, ARCH_CONVERT) == XFS_DIRX_LEAF_MAGIC(state->mp) ||
+		       INT_GET(blkinfo->magic, ARCH_CONVERT) == XFS_ATTR_LEAF_MAGIC);
+	} else {
+		ASSERT(INT_GET(blkinfo->magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+	}
+	ASSERT(!blkinfo->forw);
+	ASSERT(!blkinfo->back);
+	memcpy(root_blk->bp->data, bp->data, state->blocksize);
+	xfs_da_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
+	error = xfs_da_shrink_inode(args, child, bp);
+	return(error);
+}
+
+/*
+ * Check a node 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.
+ */
+STATIC int
+xfs_da_node_toosmall(xfs_da_state_t *state, int *action)
+{
+	xfs_da_intnode_t *node;
+	xfs_da_state_blk_t *blk;
+	xfs_da_blkinfo_t *info;
+	int count, 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_DA_NODE_MAGIC);
+	node = (xfs_da_intnode_t *)info;
+	count = INT_GET(node->hdr.count, ARCH_CONVERT);
+	if (count > (state->node_ents >> 1)) {
+		*action = 0;	/* blk over 50%, don't try to join */
+		return(0);	/* blk over 50%, don't try to join */
+	}
+
+	/*
+	 * 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.
+	 */
+	/* start with smaller blk num */
+	forward = (INT_GET(info->forw, ARCH_CONVERT)
+				< INT_GET(info->back, ARCH_CONVERT));
+	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, state->args->whichfork);
+		if (error)
+			return(error);
+		ASSERT(bp != NULL);
+
+		node = (xfs_da_intnode_t *)info;
+		count  = state->node_ents;
+		count -= state->node_ents >> 2;
+		count -= INT_GET(node->hdr.count, ARCH_CONVERT);
+		node = bp->data;
+		ASSERT(INT_GET(node->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+		count -= INT_GET(node->hdr.count, ARCH_CONVERT);
+		xfs_da_brelse(state->args->trans, bp);
+		if (count >= 0)
+			break;	/* fits with at least 25% to spare */
+	}
+	if (i >= 2) {
+		*action = 0;
+		return(0);
+	}
+
+	/*
+	 * Make altpath point to the block we want to keep (the lower
+	 * numbered block) and path point to the block we want to drop.
+	 */
+	memcpy(&state->altpath, &state->path, sizeof(state->path));
+	if (blkno < blk->blkno) {
+		error = xfs_da_path_shift(state, &state->altpath, forward,
+						 0, &retval);
+		if (error) {
+			return(error);
+		}
+		if (retval) {
+			*action = 0;
+			return(0);
+		}
+	} else {
+		error = xfs_da_path_shift(state, &state->path, forward,
+						 0, &retval);
+		if (error) {
+			return(error);
+		}
+		if (retval) {
+			*action = 0;
+			return(0);
+		}
+	}
+	*action = 1;
+	return(0);
+}
+
+/*
+ * Walk back up the tree adjusting hash values as necessary,
+ * when we stop making changes, return.
+ */
+void
+xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path)
+{
+	xfs_da_state_blk_t *blk;
+	xfs_da_intnode_t *node;
+	xfs_da_node_entry_t *btree;
+	xfs_dahash_t lasthash=0;
+	int level, count;
+
+	level = path->active-1;
+	blk = &path->blk[ level ];
+	switch (blk->magic) {
+#ifdef __KERNEL__
+	case XFS_ATTR_LEAF_MAGIC:
+		lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
+		if (count == 0)
+			return;
+		break;
+#endif
+	case XFS_DIR_LEAF_MAGIC:
+		ASSERT(XFS_DIR_IS_V1(state->mp));
+		lasthash = xfs_dir_leaf_lasthash(blk->bp, &count);
+		if (count == 0)
+			return;
+		break;
+	case XFS_DIR2_LEAFN_MAGIC:
+		ASSERT(XFS_DIR_IS_V2(state->mp));
+		lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count);
+		if (count == 0)
+			return;
+		break;
+	case XFS_DA_NODE_MAGIC:
+		lasthash = xfs_da_node_lasthash(blk->bp, &count);
+		if (count == 0)
+			return;
+		break;
+	}
+	for (blk--, level--; level >= 0; blk--, level--) {
+		node = blk->bp->data;
+		ASSERT(INT_GET(node->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+		btree = &node->btree[ blk->index ];
+		if (INT_GET(btree->hashval, ARCH_CONVERT) == lasthash)
+			break;
+		blk->hashval = lasthash;
+		INT_SET(btree->hashval, ARCH_CONVERT, lasthash);
+		xfs_da_log_buf(state->args->trans, blk->bp,
+				  XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
+
+		lasthash = INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
+	}
+}
+
+/*
+ * Remove an entry from an intermediate node.
+ */
+STATIC void
+xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk)
+{
+	xfs_da_intnode_t *node;
+	xfs_da_node_entry_t *btree;
+	int tmp;
+
+	node = drop_blk->bp->data;
+	ASSERT(drop_blk->index < INT_GET(node->hdr.count, ARCH_CONVERT));
+	ASSERT(drop_blk->index >= 0);
+
+	/*
+	 * Copy over the offending entry, or just zero it out.
+	 */
+	btree = &node->btree[drop_blk->index];
+	if (drop_blk->index < (INT_GET(node->hdr.count, ARCH_CONVERT)-1)) {
+		tmp  = INT_GET(node->hdr.count, ARCH_CONVERT) - drop_blk->index - 1;
+		tmp *= (uint)sizeof(xfs_da_node_entry_t);
+		memmove(btree, btree + 1, tmp);
+		xfs_da_log_buf(state->args->trans, drop_blk->bp,
+		    XFS_DA_LOGRANGE(node, btree, tmp));
+		btree = &node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ];
+	}
+	memset((char *)btree, 0, sizeof(xfs_da_node_entry_t));
+	xfs_da_log_buf(state->args->trans, drop_blk->bp,
+	    XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
+	INT_MOD(node->hdr.count, ARCH_CONVERT, -1);
+	xfs_da_log_buf(state->args->trans, drop_blk->bp,
+	    XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
+
+	/*
+	 * Copy the last hash value from the block to propagate upwards.
+	 */
+	btree--;
+	drop_blk->hashval = INT_GET(btree->hashval, ARCH_CONVERT);
+}
+
+/*
+ * Unbalance the btree elements between two intermediate nodes,
+ * move all Btree elements from one node into another.
+ */
+STATIC void
+xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
+				     xfs_da_state_blk_t *save_blk)
+{
+	xfs_da_intnode_t *drop_node, *save_node;
+	xfs_da_node_entry_t *btree;
+	int tmp;
+	xfs_trans_t *tp;
+
+	drop_node = drop_blk->bp->data;
+	save_node = save_blk->bp->data;
+	ASSERT(INT_GET(drop_node->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+	ASSERT(INT_GET(save_node->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+	tp = state->args->trans;
+
+	/*
+	 * If the dying block has lower hashvals, then move all the
+	 * elements in the remaining block up to make a hole.
+	 */
+	if ((INT_GET(drop_node->btree[ 0 ].hashval, ARCH_CONVERT) < INT_GET(save_node->btree[ 0 ].hashval, ARCH_CONVERT)) ||
+	    (INT_GET(drop_node->btree[ INT_GET(drop_node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT) <
+	     INT_GET(save_node->btree[ INT_GET(save_node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT)))
+	{
+		btree = &save_node->btree[ INT_GET(drop_node->hdr.count, ARCH_CONVERT) ];
+		tmp = INT_GET(save_node->hdr.count, ARCH_CONVERT) * (uint)sizeof(xfs_da_node_entry_t);
+		memmove(btree, &save_node->btree[0], tmp);
+		btree = &save_node->btree[0];
+		xfs_da_log_buf(tp, save_blk->bp,
+			XFS_DA_LOGRANGE(save_node, btree,
+				(INT_GET(save_node->hdr.count, ARCH_CONVERT) + INT_GET(drop_node->hdr.count, ARCH_CONVERT)) *
+				sizeof(xfs_da_node_entry_t)));
+	} else {
+		btree = &save_node->btree[ INT_GET(save_node->hdr.count, ARCH_CONVERT) ];
+		xfs_da_log_buf(tp, save_blk->bp,
+			XFS_DA_LOGRANGE(save_node, btree,
+				INT_GET(drop_node->hdr.count, ARCH_CONVERT) *
+				sizeof(xfs_da_node_entry_t)));
+	}
+
+	/*
+	 * Move all the B-tree elements from drop_blk to save_blk.
+	 */
+	tmp = INT_GET(drop_node->hdr.count, ARCH_CONVERT) * (uint)sizeof(xfs_da_node_entry_t);
+	memcpy(btree, &drop_node->btree[0], tmp);
+	INT_MOD(save_node->hdr.count, ARCH_CONVERT, INT_GET(drop_node->hdr.count, ARCH_CONVERT));
+
+	xfs_da_log_buf(tp, save_blk->bp,
+		XFS_DA_LOGRANGE(save_node, &save_node->hdr,
+			sizeof(save_node->hdr)));
+
+	/*
+	 * Save the last hashval in the remaining block for upward propagation.
+	 */
+	save_blk->hashval = INT_GET(save_node->btree[ INT_GET(save_node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
+}
+
+/*========================================================================
+ * Routines used for finding things in the Btree.
+ *========================================================================*/
+
+/*
+ * Walk down the Btree looking for a particular filename, filling
+ * in the state structure as we go.
+ *
+ * We will set the state structure to point to each of the elements
+ * in each of the nodes where either the hashval is or should be.
+ *
+ * We support duplicate hashval's so for each entry in the current
+ * node that could contain the desired hashval, descend.  This is a
+ * pruned depth-first tree search.
+ */
+int							/* error */
+xfs_da_node_lookup_int(xfs_da_state_t *state, int *result)
+{
+	xfs_da_state_blk_t *blk;
+	xfs_da_blkinfo_t *curr;
+	xfs_da_intnode_t *node;
+	xfs_da_node_entry_t *btree;
+	xfs_dablk_t blkno;
+	int probe, span, max, error, retval;
+	xfs_dahash_t hashval;
+	xfs_da_args_t *args;
+
+	args = state->args;
+
+	/*
+	 * Descend thru the B-tree searching each level for the right
+	 * node to use, until the right hashval is found.
+	 */
+	if (args->whichfork == XFS_DATA_FORK && XFS_DIR_IS_V2(state->mp))
+		blkno = state->mp->m_dirleafblk;
+	else
+		blkno = 0;
+	for (blk = &state->path.blk[0], state->path.active = 1;
+			 state->path.active <= XFS_DA_NODE_MAXDEPTH;
+			 blk++, state->path.active++) {
+		/*
+		 * Read the next node down in the tree.
+		 */
+		blk->blkno = blkno;
+		error = xfs_da_read_buf(args->trans, args->dp, blkno,
+					-1, &blk->bp, args->whichfork);
+		if (error) {
+			blk->blkno = 0;
+			state->path.active--;
+			return(error);
+		}
+		curr = blk->bp->data;
+		ASSERT(INT_GET(curr->magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC ||
+		       INT_GET(curr->magic, ARCH_CONVERT) == XFS_DIRX_LEAF_MAGIC(state->mp) ||
+		       INT_GET(curr->magic, ARCH_CONVERT) == XFS_ATTR_LEAF_MAGIC);
+
+		/*
+		 * Search an intermediate node for a match.
+		 */
+		blk->magic = INT_GET(curr->magic, ARCH_CONVERT);
+		if (INT_GET(curr->magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC) {
+			node = blk->bp->data;
+			blk->hashval = INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
+
+			/*
+			 * Binary search.  (note: small blocks will skip loop)
+			 */
+			max = INT_GET(node->hdr.count, ARCH_CONVERT);
+			probe = span = max / 2;
+			hashval = args->hashval;
+			for (btree = &node->btree[probe]; span > 4;
+				   btree = &node->btree[probe]) {
+				span /= 2;
+				if (INT_GET(btree->hashval, ARCH_CONVERT) < hashval)
+					probe += span;
+				else if (INT_GET(btree->hashval, ARCH_CONVERT) > hashval)
+					probe -= span;
+				else
+					break;
+			}
+			ASSERT((probe >= 0) && (probe < max));
+			ASSERT((span <= 4) || (INT_GET(btree->hashval, ARCH_CONVERT) == hashval));
+
+			/*
+			 * Since we may have duplicate hashval's, find the first
+			 * matching hashval in the node.
+			 */
+			while ((probe > 0) && (INT_GET(btree->hashval, ARCH_CONVERT) >= hashval)) {
+				btree--;
+				probe--;
+			}
+			while ((probe < max) && (INT_GET(btree->hashval, ARCH_CONVERT) < hashval)) {
+				btree++;
+				probe++;
+			}
+
+			/*
+			 * Pick the right block to descend on.
+			 */
+			if (probe == max) {
+				blk->index = max-1;
+				blkno = INT_GET(node->btree[ max-1 ].before, ARCH_CONVERT);
+			} else {
+				blk->index = probe;
+				blkno = INT_GET(btree->before, ARCH_CONVERT);
+			}
+		}
+#ifdef __KERNEL__
+		else if (INT_GET(curr->magic, ARCH_CONVERT) == XFS_ATTR_LEAF_MAGIC) {
+			blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
+			break;
+		}
+#endif
+		else if (INT_GET(curr->magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC) {
+			blk->hashval = xfs_dir_leaf_lasthash(blk->bp, NULL);
+			break;
+		}
+		else if (INT_GET(curr->magic, ARCH_CONVERT) == XFS_DIR2_LEAFN_MAGIC) {
+			blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
+			break;
+		}
+	}
+
+	/*
+	 * A leaf block that ends in the hashval that we are interested in
+	 * (final hashval == search hashval) means that the next block may
+	 * contain more entries with the same hashval, shift upward to the
+	 * next leaf and keep searching.
+	 */
+	for (;;) {
+		if (blk->magic == XFS_DIR_LEAF_MAGIC) {
+			ASSERT(XFS_DIR_IS_V1(state->mp));
+			retval = xfs_dir_leaf_lookup_int(blk->bp, args,
+								  &blk->index);
+		} else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
+			ASSERT(XFS_DIR_IS_V2(state->mp));
+			retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
+							&blk->index, state);
+		}
+#ifdef __KERNEL__
+		else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
+			retval = xfs_attr_leaf_lookup_int(blk->bp, args);
+			blk->index = args->index;
+			args->blkno = blk->blkno;
+		}
+#endif
+		if (((retval == ENOENT) || (retval == ENOATTR)) &&
+		    (blk->hashval == args->hashval)) {
+			error = xfs_da_path_shift(state, &state->path, 1, 1,
+							 &retval);
+			if (error)
+				return(error);
+			if (retval == 0) {
+				continue;
+			}
+#ifdef __KERNEL__
+			else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
+				/* path_shift() gives ENOENT */
+				retval = XFS_ERROR(ENOATTR);
+			}
+#endif
+		}
+		break;
+	}
+	*result = retval;
+	return(0);
+}
+
+/*========================================================================
+ * Utility routines.
+ *========================================================================*/
+
+/*
+ * Link a new block into a doubly linked list of blocks (of whatever type).
+ */
+int							/* error */
+xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
+			       xfs_da_state_blk_t *new_blk)
+{
+	xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
+	xfs_da_args_t *args;
+	int before=0, error;
+	xfs_dabuf_t *bp;
+
+	/*
+	 * Set up environment.
+	 */
+	args = state->args;
+	ASSERT(args != NULL);
+	old_info = old_blk->bp->data;
+	new_info = new_blk->bp->data;
+	ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
+	       old_blk->magic == XFS_DIRX_LEAF_MAGIC(state->mp) ||
+	       old_blk->magic == XFS_ATTR_LEAF_MAGIC);
+	ASSERT(old_blk->magic == INT_GET(old_info->magic, ARCH_CONVERT));
+	ASSERT(new_blk->magic == INT_GET(new_info->magic, ARCH_CONVERT));
+	ASSERT(old_blk->magic == new_blk->magic);
+
+	switch (old_blk->magic) {
+#ifdef __KERNEL__
+	case XFS_ATTR_LEAF_MAGIC:
+		before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
+		break;
+#endif
+	case XFS_DIR_LEAF_MAGIC:
+		ASSERT(XFS_DIR_IS_V1(state->mp));
+		before = xfs_dir_leaf_order(old_blk->bp, new_blk->bp);
+		break;
+	case XFS_DIR2_LEAFN_MAGIC:
+		ASSERT(XFS_DIR_IS_V2(state->mp));
+		before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
+		break;
+	case XFS_DA_NODE_MAGIC:
+		before = xfs_da_node_order(old_blk->bp, new_blk->bp);
+		break;
+	}
+
+	/*
+	 * Link blocks in appropriate order.
+	 */
+	if (before) {
+		/*
+		 * Link new block in before existing block.
+		 */
+		INT_SET(new_info->forw, ARCH_CONVERT, old_blk->blkno);
+		new_info->back = old_info->back; /* INT_: direct copy */
+		if (INT_GET(old_info->back, ARCH_CONVERT)) {
+			error = xfs_da_read_buf(args->trans, args->dp,
+						INT_GET(old_info->back,
+							ARCH_CONVERT), -1, &bp,
+						args->whichfork);
+			if (error)
+				return(error);
+			ASSERT(bp != NULL);
+			tmp_info = bp->data;
+			ASSERT(INT_GET(tmp_info->magic, ARCH_CONVERT) == INT_GET(old_info->magic, ARCH_CONVERT));
+			ASSERT(INT_GET(tmp_info->forw, ARCH_CONVERT) == old_blk->blkno);
+			INT_SET(tmp_info->forw, ARCH_CONVERT, new_blk->blkno);
+			xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
+			xfs_da_buf_done(bp);
+		}
+		INT_SET(old_info->back, ARCH_CONVERT, new_blk->blkno);
+	} else {
+		/*
+		 * Link new block in after existing block.
+		 */
+		new_info->forw = old_info->forw; /* INT_: direct copy */
+		INT_SET(new_info->back, ARCH_CONVERT, old_blk->blkno);
+		if (INT_GET(old_info->forw, ARCH_CONVERT)) {
+			error = xfs_da_read_buf(args->trans, args->dp,
+						INT_GET(old_info->forw, ARCH_CONVERT), -1, &bp,
+						args->whichfork);
+			if (error)
+				return(error);
+			ASSERT(bp != NULL);
+			tmp_info = bp->data;
+			ASSERT(INT_GET(tmp_info->magic, ARCH_CONVERT)
+				    == INT_GET(old_info->magic, ARCH_CONVERT));
+			ASSERT(INT_GET(tmp_info->back, ARCH_CONVERT)
+				    == old_blk->blkno);
+			INT_SET(tmp_info->back, ARCH_CONVERT, new_blk->blkno);
+			xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
+			xfs_da_buf_done(bp);
+		}
+		INT_SET(old_info->forw, ARCH_CONVERT, new_blk->blkno);
+	}
+
+	xfs_da_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
+	xfs_da_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
+	return(0);
+}
+
+/*
+ * Compare two intermediate nodes for "order".
+ */
+STATIC int
+xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp)
+{
+	xfs_da_intnode_t *node1, *node2;
+
+	node1 = node1_bp->data;
+	node2 = node2_bp->data;
+	ASSERT((INT_GET(node1->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC) &&
+	       (INT_GET(node2->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC));
+	if ((INT_GET(node1->hdr.count, ARCH_CONVERT) > 0) && (INT_GET(node2->hdr.count, ARCH_CONVERT) > 0) &&
+	    ((INT_GET(node2->btree[ 0 ].hashval, ARCH_CONVERT) <
+	      INT_GET(node1->btree[ 0 ].hashval, ARCH_CONVERT)) ||
+	     (INT_GET(node2->btree[ INT_GET(node2->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT) <
+	      INT_GET(node1->btree[ INT_GET(node1->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT)))) {
+		return(1);
+	}
+	return(0);
+}
+
+/*
+ * Pick up the last hashvalue from an intermediate node.
+ */
+STATIC uint
+xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count)
+{
+	xfs_da_intnode_t *node;
+
+	node = bp->data;
+	ASSERT(INT_GET(node->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+	if (count)
+		*count = INT_GET(node->hdr.count, ARCH_CONVERT);
+	if (!node->hdr.count)
+		return(0);
+	return(INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT));
+}
+
+/*
+ * Unlink a block from a doubly linked list of blocks.
+ */
+int							/* error */
+xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
+				 xfs_da_state_blk_t *save_blk)
+{
+	xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
+	xfs_da_args_t *args;
+	xfs_dabuf_t *bp;
+	int error;
+
+	/*
+	 * Set up environment.
+	 */
+	args = state->args;
+	ASSERT(args != NULL);
+	save_info = save_blk->bp->data;
+	drop_info = drop_blk->bp->data;
+	ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
+	       save_blk->magic == XFS_DIRX_LEAF_MAGIC(state->mp) ||
+	       save_blk->magic == XFS_ATTR_LEAF_MAGIC);
+	ASSERT(save_blk->magic == INT_GET(save_info->magic, ARCH_CONVERT));
+	ASSERT(drop_blk->magic == INT_GET(drop_info->magic, ARCH_CONVERT));
+	ASSERT(save_blk->magic == drop_blk->magic);
+	ASSERT((INT_GET(save_info->forw, ARCH_CONVERT) == drop_blk->blkno) ||
+	       (INT_GET(save_info->back, ARCH_CONVERT) == drop_blk->blkno));
+	ASSERT((INT_GET(drop_info->forw, ARCH_CONVERT) == save_blk->blkno) ||
+	       (INT_GET(drop_info->back, ARCH_CONVERT) == save_blk->blkno));
+
+	/*
+	 * Unlink the leaf block from the doubly linked chain of leaves.
+	 */
+	if (INT_GET(save_info->back, ARCH_CONVERT) == drop_blk->blkno) {
+		save_info->back = drop_info->back; /* INT_: direct copy */
+		if (INT_GET(drop_info->back, ARCH_CONVERT)) {
+			error = xfs_da_read_buf(args->trans, args->dp,
+						INT_GET(drop_info->back,
+							ARCH_CONVERT), -1, &bp,
+						args->whichfork);
+			if (error)
+				return(error);
+			ASSERT(bp != NULL);
+			tmp_info = bp->data;
+			ASSERT(INT_GET(tmp_info->magic, ARCH_CONVERT) == INT_GET(save_info->magic, ARCH_CONVERT));
+			ASSERT(INT_GET(tmp_info->forw, ARCH_CONVERT) == drop_blk->blkno);
+			INT_SET(tmp_info->forw, ARCH_CONVERT, save_blk->blkno);
+			xfs_da_log_buf(args->trans, bp, 0,
+						    sizeof(*tmp_info) - 1);
+			xfs_da_buf_done(bp);
+		}
+	} else {
+		save_info->forw = drop_info->forw; /* INT_: direct copy */
+		if (INT_GET(drop_info->forw, ARCH_CONVERT)) {
+			error = xfs_da_read_buf(args->trans, args->dp,
+						INT_GET(drop_info->forw, ARCH_CONVERT), -1, &bp,
+						args->whichfork);
+			if (error)
+				return(error);
+			ASSERT(bp != NULL);
+			tmp_info = bp->data;
+			ASSERT(INT_GET(tmp_info->magic, ARCH_CONVERT)
+				    == INT_GET(save_info->magic, ARCH_CONVERT));
+			ASSERT(INT_GET(tmp_info->back, ARCH_CONVERT)
+				    == drop_blk->blkno);
+			INT_SET(tmp_info->back, ARCH_CONVERT, save_blk->blkno);
+			xfs_da_log_buf(args->trans, bp, 0,
+						    sizeof(*tmp_info) - 1);
+			xfs_da_buf_done(bp);
+		}
+	}
+
+	xfs_da_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
+	return(0);
+}
+
+/*
+ * Move a path "forward" or "!forward" one block at the current level.
+ *
+ * This routine will adjust a "path" to point to the next block
+ * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
+ * Btree, including updating pointers to the intermediate nodes between
+ * the new bottom and the root.
+ */
+int							/* error */
+xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
+				 int forward, int release, int *result)
+{
+	xfs_da_state_blk_t *blk;
+	xfs_da_blkinfo_t *info;
+	xfs_da_intnode_t *node;
+	xfs_da_args_t *args;
+	xfs_dablk_t blkno=0;
+	int level, error;
+
+	/*
+	 * Roll up the Btree looking for the first block where our
+	 * current index is not at the edge of the block.  Note that
+	 * we skip the bottom layer because we want the sibling block.
+	 */
+	args = state->args;
+	ASSERT(args != NULL);
+	ASSERT(path != NULL);
+	ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
+	level = (path->active-1) - 1;	/* skip bottom layer in path */
+	for (blk = &path->blk[level]; level >= 0; blk--, level--) {
+		ASSERT(blk->bp != NULL);
+		node = blk->bp->data;
+		ASSERT(INT_GET(node->hdr.info.magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+		if (forward && (blk->index < INT_GET(node->hdr.count, ARCH_CONVERT)-1)) {
+			blk->index++;
+			blkno = INT_GET(node->btree[ blk->index ].before, ARCH_CONVERT);
+			break;
+		} else if (!forward && (blk->index > 0)) {
+			blk->index--;
+			blkno = INT_GET(node->btree[ blk->index ].before, ARCH_CONVERT);
+			break;
+		}
+	}
+	if (level < 0) {
+		*result = XFS_ERROR(ENOENT);	/* we're out of our tree */
+		ASSERT(args->oknoent);
+		return(0);
+	}
+
+	/*
+	 * Roll down the edge of the subtree until we reach the
+	 * same depth we were at originally.
+	 */
+	for (blk++, level++; level < path->active; blk++, level++) {
+		/*
+		 * Release the old block.
+		 * (if it's dirty, trans won't actually let go)
+		 */
+		if (release)
+			xfs_da_brelse(args->trans, blk->bp);
+
+		/*
+		 * Read the next child block.
+		 */
+		blk->blkno = blkno;
+		error = xfs_da_read_buf(args->trans, args->dp, blkno, -1,
+						     &blk->bp, args->whichfork);
+		if (error)
+			return(error);
+		ASSERT(blk->bp != NULL);
+		info = blk->bp->data;
+		ASSERT(INT_GET(info->magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC ||
+		       INT_GET(info->magic, ARCH_CONVERT) == XFS_DIRX_LEAF_MAGIC(state->mp) ||
+		       INT_GET(info->magic, ARCH_CONVERT) == XFS_ATTR_LEAF_MAGIC);
+		blk->magic = INT_GET(info->magic, ARCH_CONVERT);
+		if (INT_GET(info->magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC) {
+			node = (xfs_da_intnode_t *)info;
+			blk->hashval = INT_GET(node->btree[ INT_GET(node->hdr.count, ARCH_CONVERT)-1 ].hashval, ARCH_CONVERT);
+			if (forward)
+				blk->index = 0;
+			else
+				blk->index = INT_GET(node->hdr.count, ARCH_CONVERT)-1;
+			blkno = INT_GET(node->btree[ blk->index ].before, ARCH_CONVERT);
+		} else {
+			ASSERT(level == path->active-1);
+			blk->index = 0;
+			switch(blk->magic) {
+#ifdef __KERNEL__
+			case XFS_ATTR_LEAF_MAGIC:
+				blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
+								      NULL);
+				break;
+#endif
+			case XFS_DIR_LEAF_MAGIC:
+				ASSERT(XFS_DIR_IS_V1(state->mp));
+				blk->hashval = xfs_dir_leaf_lasthash(blk->bp,
+								     NULL);
+				break;
+			case XFS_DIR2_LEAFN_MAGIC:
+				ASSERT(XFS_DIR_IS_V2(state->mp));
+				blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
+								       NULL);
+				break;
+			default:
+				ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
+				       blk->magic ==
+				       XFS_DIRX_LEAF_MAGIC(state->mp));
+				break;
+			}
+		}
+	}
+	*result = 0;
+	return(0);
+}
+
+
+/*========================================================================
+ * Utility routines.
+ *========================================================================*/
+
+/*
+ * Implement a simple hash on a character string.
+ * Rotate the hash value by 7 bits, then XOR each character in.
+ * This is implemented with some source-level loop unrolling.
+ */
+xfs_dahash_t
+xfs_da_hashname(uchar_t *name, int namelen)
+{
+	xfs_dahash_t hash;
+
+#ifdef SLOWVERSION
+	/*
+	 * This is the old one-byte-at-a-time version.
+	 */
+	for (hash = 0; namelen > 0; namelen--)
+		hash = *name++ ^ rol32(hash, 7);
+
+	return(hash);
+#else
+	/*
+	 * Do four characters at a time as long as we can.
+	 */
+	for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
+		hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
+		       (name[3] << 0) ^ rol32(hash, 7 * 4);
+
+	/*
+	 * Now do the rest of the characters.
+	 */
+	switch (namelen) {
+	case 3:
+		return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
+		       rol32(hash, 7 * 3);
+	case 2:
+		return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
+	case 1:
+		return (name[0] << 0) ^ rol32(hash, 7 * 1);
+	case 0:
+		return hash;
+	}
+	/* NOTREACHED */
+#endif
+	return 0; /* keep gcc happy */
+}
+
+/*
+ * Add a block to the btree ahead of the file.
+ * Return the new block number to the caller.
+ */
+int
+xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
+{
+	xfs_fileoff_t bno, b;
+	xfs_bmbt_irec_t map;
+	xfs_bmbt_irec_t	*mapp;
+	xfs_inode_t *dp;
+	int nmap, error, w, count, c, got, i, mapi;
+	xfs_fsize_t size;
+	xfs_trans_t *tp;
+	xfs_mount_t *mp;
+
+	dp = args->dp;
+	mp = dp->i_mount;
+	w = args->whichfork;
+	tp = args->trans;
+	/*
+	 * For new directories adjust the file offset and block count.
+	 */
+	if (w == XFS_DATA_FORK && XFS_DIR_IS_V2(mp)) {
+		bno = mp->m_dirleafblk;
+		count = mp->m_dirblkfsbs;
+	} else {
+		bno = 0;
+		count = 1;
+	}
+	/*
+	 * Find a spot in the file space to put the new block.
+	 */
+	if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, w))) {
+		return error;
+	}
+	if (w == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
+		ASSERT(bno >= mp->m_dirleafblk && bno < mp->m_dirfreeblk);
+	/*
+	 * Try mapping it in one filesystem block.
+	 */
+	nmap = 1;
+	ASSERT(args->firstblock != NULL);
+	if ((error = xfs_bmapi(tp, dp, bno, count,
+			XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|
+			XFS_BMAPI_CONTIG,
+			args->firstblock, args->total, &map, &nmap,
+			args->flist))) {
+		return error;
+	}
+	ASSERT(nmap <= 1);
+	if (nmap == 1) {
+		mapp = &map;
+		mapi = 1;
+	}
+	/*
+	 * If we didn't get it and the block might work if fragmented,
+	 * try without the CONTIG flag.  Loop until we get it all.
+	 */
+	else if (nmap == 0 && count > 1) {
+		mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
+		for (b = bno, mapi = 0; b < bno + count; ) {
+			nmap = MIN(XFS_BMAP_MAX_NMAP, count);
+			c = (int)(bno + count - b);
+			if ((error = xfs_bmapi(tp, dp, b, c,
+					XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|
+					XFS_BMAPI_METADATA,
+					args->firstblock, args->total,
+					&mapp[mapi], &nmap, args->flist))) {
+				kmem_free(mapp, sizeof(*mapp) * count);
+				return error;
+			}
+			if (nmap < 1)
+				break;
+			mapi += nmap;
+			b = mapp[mapi - 1].br_startoff +
+			    mapp[mapi - 1].br_blockcount;
+		}
+	} else {
+		mapi = 0;
+		mapp = NULL;
+	}
+	/*
+	 * Count the blocks we got, make sure it matches the total.
+	 */
+	for (i = 0, got = 0; i < mapi; i++)
+		got += mapp[i].br_blockcount;
+	if (got != count || mapp[0].br_startoff != bno ||
+	    mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
+	    bno + count) {
+		if (mapp != &map)
+			kmem_free(mapp, sizeof(*mapp) * count);
+		return XFS_ERROR(ENOSPC);
+	}
+	if (mapp != &map)
+		kmem_free(mapp, sizeof(*mapp) * count);
+	*new_blkno = (xfs_dablk_t)bno;
+	/*
+	 * For version 1 directories, adjust the file size if it changed.
+	 */
+	if (w == XFS_DATA_FORK && XFS_DIR_IS_V1(mp)) {
+		ASSERT(mapi == 1);
+		if ((error = xfs_bmap_last_offset(tp, dp, &bno, w)))
+			return error;
+		size = XFS_FSB_TO_B(mp, bno);
+		if (size != dp->i_d.di_size) {
+			dp->i_d.di_size = size;
+			xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
+		}
+	}
+	return 0;
+}
+
+/*
+ * Ick.  We need to always be able to remove a btree block, even
+ * if there's no space reservation because the filesystem is full.
+ * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
+ * It swaps the target block with the last block in the file.  The
+ * last block in the file can always be removed since it can't cause
+ * a bmap btree split to do that.
+ */
+STATIC int
+xfs_da_swap_lastblock(xfs_da_args_t *args, xfs_dablk_t *dead_blknop,
+		      xfs_dabuf_t **dead_bufp)
+{
+	xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
+	xfs_dabuf_t *dead_buf, *last_buf, *sib_buf, *par_buf;
+	xfs_fileoff_t lastoff;
+	xfs_inode_t *ip;
+	xfs_trans_t *tp;
+	xfs_mount_t *mp;
+	int error, w, entno, level, dead_level;
+	xfs_da_blkinfo_t *dead_info, *sib_info;
+	xfs_da_intnode_t *par_node, *dead_node;
+	xfs_dir_leafblock_t *dead_leaf;
+	xfs_dir2_leaf_t *dead_leaf2;
+	xfs_dahash_t dead_hash;
+
+	dead_buf = *dead_bufp;
+	dead_blkno = *dead_blknop;
+	tp = args->trans;
+	ip = args->dp;
+	w = args->whichfork;
+	ASSERT(w == XFS_DATA_FORK);
+	mp = ip->i_mount;
+	if (XFS_DIR_IS_V2(mp)) {
+		lastoff = mp->m_dirfreeblk;
+		error = xfs_bmap_last_before(tp, ip, &lastoff, w);
+	} else
+		error = xfs_bmap_last_offset(tp, ip, &lastoff, w);
+	if (error)
+		return error;
+	if (unlikely(lastoff == 0)) {
+		XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
+				 mp);
+		return XFS_ERROR(EFSCORRUPTED);
+	}
+	/*
+	 * Read the last block in the btree space.
+	 */
+	last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
+	if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
+		return error;
+	/*
+	 * Copy the last block into the dead buffer and log it.
+	 */
+	memcpy(dead_buf->data, last_buf->data, mp->m_dirblksize);
+	xfs_da_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
+	dead_info = dead_buf->data;
+	/*
+	 * Get values from the moved block.
+	 */
+	if (INT_GET(dead_info->magic, ARCH_CONVERT) == XFS_DIR_LEAF_MAGIC) {
+		ASSERT(XFS_DIR_IS_V1(mp));
+		dead_leaf = (xfs_dir_leafblock_t *)dead_info;
+		dead_level = 0;
+		dead_hash =
+			INT_GET(dead_leaf->entries[INT_GET(dead_leaf->hdr.count, ARCH_CONVERT) - 1].hashval, ARCH_CONVERT);
+	} else if (INT_GET(dead_info->magic, ARCH_CONVERT) == XFS_DIR2_LEAFN_MAGIC) {
+		ASSERT(XFS_DIR_IS_V2(mp));
+		dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
+		dead_level = 0;
+		dead_hash = INT_GET(dead_leaf2->ents[INT_GET(dead_leaf2->hdr.count, ARCH_CONVERT) - 1].hashval, ARCH_CONVERT);
+	} else {
+		ASSERT(INT_GET(dead_info->magic, ARCH_CONVERT) == XFS_DA_NODE_MAGIC);
+		dead_node = (xfs_da_intnode_t *)dead_info;
+		dead_level = INT_GET(dead_node->hdr.level, ARCH_CONVERT);
+		dead_hash = INT_GET(dead_node->btree[INT_GET(dead_node->hdr.count, ARCH_CONVERT) - 1].hashval, ARCH_CONVERT);
+	}
+	sib_buf = par_buf = NULL;
+	/*
+	 * If the moved block has a left sibling, fix up the pointers.
+	 */
+	if ((sib_blkno = INT_GET(dead_info->back, ARCH_CONVERT))) {
+		if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
+			goto done;
+		sib_info = sib_buf->data;
+		if (unlikely(
+		    INT_GET(sib_info->forw, ARCH_CONVERT) != last_blkno ||
+		    INT_GET(sib_info->magic, ARCH_CONVERT) != INT_GET(dead_info->magic, ARCH_CONVERT))) {
+			XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
+					 XFS_ERRLEVEL_LOW, mp);
+			error = XFS_ERROR(EFSCORRUPTED);
+			goto done;
+		}
+		INT_SET(sib_info->forw, ARCH_CONVERT, dead_blkno);
+		xfs_da_log_buf(tp, sib_buf,
+			XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
+					sizeof(sib_info->forw)));
+		xfs_da_buf_done(sib_buf);
+		sib_buf = NULL;
+	}
+	/*
+	 * If the moved block has a right sibling, fix up the pointers.
+	 */
+	if ((sib_blkno = INT_GET(dead_info->forw, ARCH_CONVERT))) {
+		if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
+			goto done;
+		sib_info = sib_buf->data;
+		if (unlikely(
+		       INT_GET(sib_info->back, ARCH_CONVERT) != last_blkno
+		    || INT_GET(sib_info->magic, ARCH_CONVERT)
+				!= INT_GET(dead_info->magic, ARCH_CONVERT))) {
+			XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
+					 XFS_ERRLEVEL_LOW, mp);
+			error = XFS_ERROR(EFSCORRUPTED);
+			goto done;
+		}
+		INT_SET(sib_info->back, ARCH_CONVERT, dead_blkno);
+		xfs_da_log_buf(tp, sib_buf,
+			XFS_DA_LOGRANGE(sib_info, &sib_info->back,
+					sizeof(sib_info->back)));
+		xfs_da_buf_done(sib_buf);
+		sib_buf = NULL;
+	}
+	par_blkno = XFS_DIR_IS_V1(mp) ? 0 : mp->m_dirleafblk;
+	level = -1;
+	/*
+	 * Walk down the tree looking for the parent of the moved block.
+	 */
+	for (;;) {
+		if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
+			goto done;
+		par_node = par_buf->data;
+		if (unlikely(
+		    INT_GET(par_node->hdr.info.magic, ARCH_CONVERT) != XFS_DA_NODE_MAGIC ||
+		    (level >= 0 && level != INT_GET(par_node->hdr.level, ARCH_CONVERT) + 1))) {
+			XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
+					 XFS_ERRLEVEL_LOW, mp);
+			error = XFS_ERROR(EFSCORRUPTED);
+			goto done;
+		}
+		level = INT_GET(par_node->hdr.level, ARCH_CONVERT);
+		for (entno = 0;
+		     entno < INT_GET(par_node->hdr.count, ARCH_CONVERT) &&
+		     INT_GET(par_node->btree[entno].hashval, ARCH_CONVERT) < dead_hash;
+		     entno++)
+			continue;
+		if (unlikely(entno == INT_GET(par_node->hdr.count, ARCH_CONVERT))) {
+			XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
+					 XFS_ERRLEVEL_LOW, mp);
+			error = XFS_ERROR(EFSCORRUPTED);
+			goto done;
+		}
+		par_blkno = INT_GET(par_node->btree[entno].before, ARCH_CONVERT);
+		if (level == dead_level + 1)
+			break;
+		xfs_da_brelse(tp, par_buf);
+		par_buf = NULL;
+	}
+	/*
+	 * We're in the right parent block.
+	 * Look for the right entry.
+	 */
+	for (;;) {
+		for (;
+		     entno < INT_GET(par_node->hdr.count, ARCH_CONVERT) &&
+		     INT_GET(par_node->btree[entno].before, ARCH_CONVERT) != last_blkno;
+		     entno++)
+			continue;
+		if (entno < INT_GET(par_node->hdr.count, ARCH_CONVERT))
+			break;
+		par_blkno = INT_GET(par_node->hdr.info.forw, ARCH_CONVERT);
+		xfs_da_brelse(tp, par_buf);
+		par_buf = NULL;
+		if (unlikely(par_blkno == 0)) {
+			XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
+					 XFS_ERRLEVEL_LOW, mp);
+			error = XFS_ERROR(EFSCORRUPTED);
+			goto done;
+		}
+		if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
+			goto done;
+		par_node = par_buf->data;
+		if (unlikely(
+		    INT_GET(par_node->hdr.level, ARCH_CONVERT) != level ||
+		    INT_GET(par_node->hdr.info.magic, ARCH_CONVERT) != XFS_DA_NODE_MAGIC)) {
+			XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
+					 XFS_ERRLEVEL_LOW, mp);
+			error = XFS_ERROR(EFSCORRUPTED);
+			goto done;
+		}
+		entno = 0;
+	}
+	/*
+	 * Update the parent entry pointing to the moved block.
+	 */
+	INT_SET(par_node->btree[entno].before, ARCH_CONVERT, dead_blkno);
+	xfs_da_log_buf(tp, par_buf,
+		XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
+				sizeof(par_node->btree[entno].before)));
+	xfs_da_buf_done(par_buf);
+	xfs_da_buf_done(dead_buf);
+	*dead_blknop = last_blkno;
+	*dead_bufp = last_buf;
+	return 0;
+done:
+	if (par_buf)
+		xfs_da_brelse(tp, par_buf);
+	if (sib_buf)
+		xfs_da_brelse(tp, sib_buf);
+	xfs_da_brelse(tp, last_buf);
+	return error;
+}
+
+/*
+ * Remove a btree block from a directory or attribute.
+ */
+int
+xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
+		    xfs_dabuf_t *dead_buf)
+{
+	xfs_inode_t *dp;
+	int done, error, w, count;
+	xfs_fileoff_t bno;
+	xfs_fsize_t size;
+	xfs_trans_t *tp;
+	xfs_mount_t *mp;
+
+	dp = args->dp;
+	w = args->whichfork;
+	tp = args->trans;
+	mp = dp->i_mount;
+	if (w == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
+		count = mp->m_dirblkfsbs;
+	else
+		count = 1;
+	for (;;) {
+		/*
+		 * Remove extents.  If we get ENOSPC for a dir we have to move
+		 * the last block to the place we want to kill.
+		 */
+		if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
+				XFS_BMAPI_AFLAG(w)|XFS_BMAPI_METADATA,
+				0, args->firstblock, args->flist,
+				&done)) == ENOSPC) {
+			if (w != XFS_DATA_FORK)
+				goto done;
+			if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
+					&dead_buf)))
+				goto done;
+		} else if (error)
+			goto done;
+		else
+			break;
+	}
+	ASSERT(done);
+	xfs_da_binval(tp, dead_buf);
+	/*
+	 * Adjust the directory size for version 1.
+	 */
+	if (w == XFS_DATA_FORK && XFS_DIR_IS_V1(mp)) {
+		if ((error = xfs_bmap_last_offset(tp, dp, &bno, w)))
+			return error;
+		size = XFS_FSB_TO_B(dp->i_mount, bno);
+		if (size != dp->i_d.di_size) {
+			dp->i_d.di_size = size;
+			xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
+		}
+	}
+	return 0;
+done:
+	xfs_da_binval(tp, dead_buf);
+	return error;
+}
+
+/*
+ * See if the mapping(s) for this btree block are valid, i.e.
+ * don't contain holes, are logically contiguous, and cover the whole range.
+ */
+STATIC int
+xfs_da_map_covers_blocks(
+	int		nmap,
+	xfs_bmbt_irec_t	*mapp,
+	xfs_dablk_t	bno,
+	int		count)
+{
+	int		i;
+	xfs_fileoff_t	off;
+
+	for (i = 0, off = bno; i < nmap; i++) {
+		if (mapp[i].br_startblock == HOLESTARTBLOCK ||
+		    mapp[i].br_startblock == DELAYSTARTBLOCK) {
+			return 0;
+		}
+		if (off != mapp[i].br_startoff) {
+			return 0;
+		}
+		off += mapp[i].br_blockcount;
+	}
+	return off == bno + count;
+}
+
+/*
+ * Make a dabuf.
+ * Used for get_buf, read_buf, read_bufr, and reada_buf.
+ */
+STATIC int
+xfs_da_do_buf(
+	xfs_trans_t	*trans,
+	xfs_inode_t	*dp,
+	xfs_dablk_t	bno,
+	xfs_daddr_t	*mappedbnop,
+	xfs_dabuf_t	**bpp,
+	int		whichfork,
+	int		caller,
+	inst_t		*ra)
+{
+	xfs_buf_t	*bp = NULL;
+	xfs_buf_t	**bplist;
+	int		error=0;
+	int		i;
+	xfs_bmbt_irec_t	map;
+	xfs_bmbt_irec_t	*mapp;
+	xfs_daddr_t	mappedbno;
+	xfs_mount_t	*mp;
+	int		nbplist=0;
+	int		nfsb;
+	int		nmap;
+	xfs_dabuf_t	*rbp;
+
+	mp = dp->i_mount;
+	if (whichfork == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
+		nfsb = mp->m_dirblkfsbs;
+	else
+		nfsb = 1;
+	mappedbno = *mappedbnop;
+	/*
+	 * Caller doesn't have a mapping.  -2 means don't complain
+	 * if we land in a hole.
+	 */
+	if (mappedbno == -1 || mappedbno == -2) {
+		/*
+		 * Optimize the one-block case.
+		 */
+		if (nfsb == 1) {
+			xfs_fsblock_t	fsb;
+
+			if ((error =
+			    xfs_bmapi_single(trans, dp, whichfork, &fsb,
+				    (xfs_fileoff_t)bno))) {
+				return error;
+			}
+			mapp = &map;
+			if (fsb == NULLFSBLOCK) {
+				nmap = 0;
+			} else {
+				map.br_startblock = fsb;
+				map.br_startoff = (xfs_fileoff_t)bno;
+				map.br_blockcount = 1;
+				nmap = 1;
+			}
+		} else {
+			mapp = kmem_alloc(sizeof(*mapp) * nfsb, KM_SLEEP);
+			nmap = nfsb;
+			if ((error = xfs_bmapi(trans, dp, (xfs_fileoff_t)bno,
+					nfsb,
+					XFS_BMAPI_METADATA |
+						XFS_BMAPI_AFLAG(whichfork),
+					NULL, 0, mapp, &nmap, NULL)))
+				goto exit0;
+		}
+	} else {
+		map.br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
+		map.br_startoff = (xfs_fileoff_t)bno;
+		map.br_blockcount = nfsb;
+		mapp = &map;
+		nmap = 1;
+	}
+	if (!xfs_da_map_covers_blocks(nmap, mapp, bno, nfsb)) {
+		error = mappedbno == -2 ? 0 : XFS_ERROR(EFSCORRUPTED);
+		if (unlikely(error == EFSCORRUPTED)) {
+			if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
+				int	i;
+				cmn_err(CE_ALERT, "xfs_da_do_buf: bno %lld\n",
+					(long long)bno);
+				cmn_err(CE_ALERT, "dir: inode %lld\n",
+					(long long)dp->i_ino);
+				for (i = 0; i < nmap; i++) {
+					cmn_err(CE_ALERT,
+						"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d\n",
+						i,
+						(long long)mapp[i].br_startoff,
+						(long long)mapp[i].br_startblock,
+						(long long)mapp[i].br_blockcount,
+						mapp[i].br_state);
+				}
+			}
+			XFS_ERROR_REPORT("xfs_da_do_buf(1)",
+					 XFS_ERRLEVEL_LOW, mp);
+		}
+		goto exit0;
+	}
+	if (caller != 3 && nmap > 1) {
+		bplist = kmem_alloc(sizeof(*bplist) * nmap, KM_SLEEP);
+		nbplist = 0;
+	} else
+		bplist = NULL;
+	/*
+	 * Turn the mapping(s) into buffer(s).
+	 */
+	for (i = 0; i < nmap; i++) {
+		int	nmapped;
+
+		mappedbno = XFS_FSB_TO_DADDR(mp, mapp[i].br_startblock);
+		if (i == 0)
+			*mappedbnop = mappedbno;
+		nmapped = (int)XFS_FSB_TO_BB(mp, mapp[i].br_blockcount);
+		switch (caller) {
+		case 0:
+			bp = xfs_trans_get_buf(trans, mp->m_ddev_targp,
+				mappedbno, nmapped, 0);
+			error = bp ? XFS_BUF_GETERROR(bp) : XFS_ERROR(EIO);
+			break;
+		case 1:
+#ifndef __KERNEL__
+		case 2:
+#endif
+			bp = NULL;
+			error = xfs_trans_read_buf(mp, trans, mp->m_ddev_targp,
+				mappedbno, nmapped, 0, &bp);
+			break;
+#ifdef __KERNEL__
+		case 3:
+			xfs_baread(mp->m_ddev_targp, mappedbno, nmapped);
+			error = 0;
+			bp = NULL;
+			break;
+#endif
+		}
+		if (error) {
+			if (bp)
+				xfs_trans_brelse(trans, bp);
+			goto exit1;
+		}
+		if (!bp)
+			continue;
+		if (caller == 1) {
+			if (whichfork == XFS_ATTR_FORK) {
+				XFS_BUF_SET_VTYPE_REF(bp, B_FS_ATTR_BTREE,
+						XFS_ATTR_BTREE_REF);
+			} else {
+				XFS_BUF_SET_VTYPE_REF(bp, B_FS_DIR_BTREE,
+						XFS_DIR_BTREE_REF);
+			}
+		}
+		if (bplist) {
+			bplist[nbplist++] = bp;
+		}
+	}
+	/*
+	 * Build a dabuf structure.
+	 */
+	if (bplist) {
+		rbp = xfs_da_buf_make(nbplist, bplist, ra);
+	} else if (bp)
+		rbp = xfs_da_buf_make(1, &bp, ra);
+	else
+		rbp = NULL;
+	/*
+	 * For read_buf, check the magic number.
+	 */
+	if (caller == 1) {
+		xfs_dir2_data_t		*data;
+		xfs_dir2_free_t		*free;
+		xfs_da_blkinfo_t	*info;
+		uint			magic, magic1;
+
+		info = rbp->data;
+		data = rbp->data;
+		free = rbp->data;
+		magic = INT_GET(info->magic, ARCH_CONVERT);
+		magic1 = INT_GET(data->hdr.magic, ARCH_CONVERT);
+		if (unlikely(
+		    XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
+				   (magic != XFS_DIR_LEAF_MAGIC) &&
+				   (magic != XFS_ATTR_LEAF_MAGIC) &&
+				   (magic != XFS_DIR2_LEAF1_MAGIC) &&
+				   (magic != XFS_DIR2_LEAFN_MAGIC) &&
+				   (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
+				   (magic1 != XFS_DIR2_DATA_MAGIC) &&
+				   (INT_GET(free->hdr.magic, ARCH_CONVERT) != XFS_DIR2_FREE_MAGIC),
+				mp, XFS_ERRTAG_DA_READ_BUF,
+				XFS_RANDOM_DA_READ_BUF))) {
+			xfs_buftrace("DA READ ERROR", rbp->bps[0]);
+			XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
+					     XFS_ERRLEVEL_LOW, mp, info);
+			error = XFS_ERROR(EFSCORRUPTED);
+			xfs_da_brelse(trans, rbp);
+			nbplist = 0;
+			goto exit1;
+		}
+	}
+	if (bplist) {
+		kmem_free(bplist, sizeof(*bplist) * nmap);
+	}
+	if (mapp != &map) {
+		kmem_free(mapp, sizeof(*mapp) * nfsb);
+	}
+	if (bpp)
+		*bpp = rbp;
+	return 0;
+exit1:
+	if (bplist) {
+		for (i = 0; i < nbplist; i++)
+			xfs_trans_brelse(trans, bplist[i]);
+		kmem_free(bplist, sizeof(*bplist) * nmap);
+	}
+exit0:
+	if (mapp != &map)
+		kmem_free(mapp, sizeof(*mapp) * nfsb);
+	if (bpp)
+		*bpp = NULL;
+	return error;
+}
+
+/*
+ * Get a buffer for the dir/attr block.
+ */
+int
+xfs_da_get_buf(
+	xfs_trans_t	*trans,
+	xfs_inode_t	*dp,
+	xfs_dablk_t	bno,
+	xfs_daddr_t		mappedbno,
+	xfs_dabuf_t	**bpp,
+	int		whichfork)
+{
+	return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 0,
+						 (inst_t *)__return_address);
+}
+
+/*
+ * Get a buffer for the dir/attr block, fill in the contents.
+ */
+int
+xfs_da_read_buf(
+	xfs_trans_t	*trans,
+	xfs_inode_t	*dp,
+	xfs_dablk_t	bno,
+	xfs_daddr_t		mappedbno,
+	xfs_dabuf_t	**bpp,
+	int		whichfork)
+{
+	return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 1,
+		(inst_t *)__return_address);
+}
+
+/*
+ * Readahead the dir/attr block.
+ */
+xfs_daddr_t
+xfs_da_reada_buf(
+	xfs_trans_t	*trans,
+	xfs_inode_t	*dp,
+	xfs_dablk_t	bno,
+	int		whichfork)
+{
+	xfs_daddr_t		rval;
+
+	rval = -1;
+	if (xfs_da_do_buf(trans, dp, bno, &rval, NULL, whichfork, 3,
+			(inst_t *)__return_address))
+		return -1;
+	else
+		return rval;
+}
+
+/*
+ * Calculate the number of bits needed to hold i different values.
+ */
+uint
+xfs_da_log2_roundup(uint i)
+{
+	uint rval;
+
+	for (rval = 0; rval < NBBY * sizeof(i); rval++) {
+		if ((1 << rval) >= i)
+			break;
+	}
+	return(rval);
+}
+
+kmem_zone_t *xfs_da_state_zone;	/* anchor for state struct zone */
+kmem_zone_t *xfs_dabuf_zone;		/* dabuf zone */
+
+/*
+ * Allocate a dir-state structure.
+ * We don't put them on the stack since they're large.
+ */
+xfs_da_state_t *
+xfs_da_state_alloc(void)
+{
+	return kmem_zone_zalloc(xfs_da_state_zone, KM_SLEEP);
+}
+
+/*
+ * Kill the altpath contents of a da-state structure.
+ */
+void
+xfs_da_state_kill_altpath(xfs_da_state_t *state)
+{
+	int	i;
+
+	for (i = 0; i < state->altpath.active; i++) {
+		if (state->altpath.blk[i].bp) {
+			if (state->altpath.blk[i].bp != state->path.blk[i].bp)
+				xfs_da_buf_done(state->altpath.blk[i].bp);
+			state->altpath.blk[i].bp = NULL;
+		}
+	}
+	state->altpath.active = 0;
+}
+
+/*
+ * Free a da-state structure.
+ */
+void
+xfs_da_state_free(xfs_da_state_t *state)
+{
+	int	i;
+
+	xfs_da_state_kill_altpath(state);
+	for (i = 0; i < state->path.active; i++) {
+		if (state->path.blk[i].bp)
+			xfs_da_buf_done(state->path.blk[i].bp);
+	}
+	if (state->extravalid && state->extrablk.bp)
+		xfs_da_buf_done(state->extrablk.bp);
+#ifdef DEBUG
+	memset((char *)state, 0, sizeof(*state));
+#endif /* DEBUG */
+	kmem_zone_free(xfs_da_state_zone, state);
+}
+
+#ifdef XFS_DABUF_DEBUG
+xfs_dabuf_t	*xfs_dabuf_global_list;
+lock_t		xfs_dabuf_global_lock;
+#endif
+
+/*
+ * Create a dabuf.
+ */
+/* ARGSUSED */
+STATIC xfs_dabuf_t *
+xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra)
+{
+	xfs_buf_t	*bp;
+	xfs_dabuf_t	*dabuf;
+	int		i;
+	int		off;
+
+	if (nbuf == 1)
+		dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_SLEEP);
+	else
+		dabuf = kmem_alloc(XFS_DA_BUF_SIZE(nbuf), KM_SLEEP);
+	dabuf->dirty = 0;
+#ifdef XFS_DABUF_DEBUG
+	dabuf->ra = ra;
+	dabuf->target = XFS_BUF_TARGET(bps[0]);
+	dabuf->blkno = XFS_BUF_ADDR(bps[0]);
+#endif
+	if (nbuf == 1) {
+		dabuf->nbuf = 1;
+		bp = bps[0];
+		dabuf->bbcount = (short)BTOBB(XFS_BUF_COUNT(bp));
+		dabuf->data = XFS_BUF_PTR(bp);
+		dabuf->bps[0] = bp;
+	} else {
+		dabuf->nbuf = nbuf;
+		for (i = 0, dabuf->bbcount = 0; i < nbuf; i++) {
+			dabuf->bps[i] = bp = bps[i];
+			dabuf->bbcount += BTOBB(XFS_BUF_COUNT(bp));
+		}
+		dabuf->data = kmem_alloc(BBTOB(dabuf->bbcount), KM_SLEEP);
+		for (i = off = 0; i < nbuf; i++, off += XFS_BUF_COUNT(bp)) {
+			bp = bps[i];
+			memcpy((char *)dabuf->data + off, XFS_BUF_PTR(bp),
+				XFS_BUF_COUNT(bp));
+		}
+	}
+#ifdef XFS_DABUF_DEBUG
+	{
+		SPLDECL(s);
+		xfs_dabuf_t	*p;
+
+		s = mutex_spinlock(&xfs_dabuf_global_lock);
+		for (p = xfs_dabuf_global_list; p; p = p->next) {
+			ASSERT(p->blkno != dabuf->blkno ||
+			       p->target != dabuf->target);
+		}
+		dabuf->prev = NULL;
+		if (xfs_dabuf_global_list)
+			xfs_dabuf_global_list->prev = dabuf;
+		dabuf->next = xfs_dabuf_global_list;
+		xfs_dabuf_global_list = dabuf;
+		mutex_spinunlock(&xfs_dabuf_global_lock, s);
+	}
+#endif
+	return dabuf;
+}
+
+/*
+ * Un-dirty a dabuf.
+ */
+STATIC void
+xfs_da_buf_clean(xfs_dabuf_t *dabuf)
+{
+	xfs_buf_t	*bp;
+	int		i;
+	int		off;
+
+	if (dabuf->dirty) {
+		ASSERT(dabuf->nbuf > 1);
+		dabuf->dirty = 0;
+		for (i = off = 0; i < dabuf->nbuf;
+				i++, off += XFS_BUF_COUNT(bp)) {
+			bp = dabuf->bps[i];
+			memcpy(XFS_BUF_PTR(bp), (char *)dabuf->data + off,
+				XFS_BUF_COUNT(bp));
+		}
+	}
+}
+
+/*
+ * Release a dabuf.
+ */
+void
+xfs_da_buf_done(xfs_dabuf_t *dabuf)
+{
+	ASSERT(dabuf);
+	ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
+	if (dabuf->dirty)
+		xfs_da_buf_clean(dabuf);
+	if (dabuf->nbuf > 1)
+		kmem_free(dabuf->data, BBTOB(dabuf->bbcount));
+#ifdef XFS_DABUF_DEBUG
+	{
+		SPLDECL(s);
+
+		s = mutex_spinlock(&xfs_dabuf_global_lock);
+		if (dabuf->prev)
+			dabuf->prev->next = dabuf->next;
+		else
+			xfs_dabuf_global_list = dabuf->next;
+		if (dabuf->next)
+			dabuf->next->prev = dabuf->prev;
+		mutex_spinunlock(&xfs_dabuf_global_lock, s);
+	}
+	memset(dabuf, 0, XFS_DA_BUF_SIZE(dabuf->nbuf));
+#endif
+	if (dabuf->nbuf == 1)
+		kmem_zone_free(xfs_dabuf_zone, dabuf);
+	else
+		kmem_free(dabuf, XFS_DA_BUF_SIZE(dabuf->nbuf));
+}
+
+/*
+ * Log transaction from a dabuf.
+ */
+void
+xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
+{
+	xfs_buf_t	*bp;
+	uint		f;
+	int		i;
+	uint		l;
+	int		off;
+
+	ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
+	if (dabuf->nbuf == 1) {
+		ASSERT(dabuf->data == (void *)XFS_BUF_PTR(dabuf->bps[0]));
+		xfs_trans_log_buf(tp, dabuf->bps[0], first, last);
+		return;
+	}
+	dabuf->dirty = 1;
+	ASSERT(first <= last);
+	for (i = off = 0; i < dabuf->nbuf; i++, off += XFS_BUF_COUNT(bp)) {
+		bp = dabuf->bps[i];
+		f = off;
+		l = f + XFS_BUF_COUNT(bp) - 1;
+		if (f < first)
+			f = first;
+		if (l > last)
+			l = last;
+		if (f <= l)
+			xfs_trans_log_buf(tp, bp, f - off, l - off);
+		/*
+		 * B_DONE is set by xfs_trans_log buf.
+		 * If we don't set it on a new buffer (get not read)
+		 * then if we don't put anything in the buffer it won't
+		 * be set, and at commit it it released into the cache,
+		 * and then a read will fail.
+		 */
+		else if (!(XFS_BUF_ISDONE(bp)))
+		  XFS_BUF_DONE(bp);
+	}
+	ASSERT(last < off);
+}
+
+/*
+ * Release dabuf from a transaction.
+ * Have to free up the dabuf before the buffers are released,
+ * since the synchronization on the dabuf is really the lock on the buffer.
+ */
+void
+xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
+{
+	xfs_buf_t	*bp;
+	xfs_buf_t	**bplist;
+	int		i;
+	int		nbuf;
+
+	ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
+	if ((nbuf = dabuf->nbuf) == 1) {
+		bplist = &bp;
+		bp = dabuf->bps[0];
+	} else {
+		bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
+		memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
+	}
+	xfs_da_buf_done(dabuf);
+	for (i = 0; i < nbuf; i++)
+		xfs_trans_brelse(tp, bplist[i]);
+	if (bplist != &bp)
+		kmem_free(bplist, nbuf * sizeof(*bplist));
+}
+
+/*
+ * Invalidate dabuf from a transaction.
+ */
+void
+xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
+{
+	xfs_buf_t	*bp;
+	xfs_buf_t	**bplist;
+	int		i;
+	int		nbuf;
+
+	ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
+	if ((nbuf = dabuf->nbuf) == 1) {
+		bplist = &bp;
+		bp = dabuf->bps[0];
+	} else {
+		bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
+		memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
+	}
+	xfs_da_buf_done(dabuf);
+	for (i = 0; i < nbuf; i++)
+		xfs_trans_binval(tp, bplist[i]);
+	if (bplist != &bp)
+		kmem_free(bplist, nbuf * sizeof(*bplist));
+}
+
+/*
+ * Get the first daddr from a dabuf.
+ */
+xfs_daddr_t
+xfs_da_blkno(xfs_dabuf_t *dabuf)
+{
+	ASSERT(dabuf->nbuf);
+	ASSERT(dabuf->data);
+	return XFS_BUF_ADDR(dabuf->bps[0]);
+}