fs/xfs/libxfs/xfs_attr_leaf.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
  * Copyright (c) 2013 Red Hat, Inc.
  * All Rights Reserved.
  */
 #include "xfs.h"
 #include "xfs_fs.h"
 #include "xfs_shared.h"
 #include "xfs_format.h"
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_sb.h"
 #include "xfs_mount.h"
 #include "xfs_da_format.h"
 #include "xfs_da_btree.h"
 #include "xfs_inode.h"
 #include "xfs_trans.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_bmap.h"
 #include "xfs_attr_sf.h"
 #include "xfs_attr_remote.h"
 #include "xfs_attr.h"
 #include "xfs_attr_leaf.h"
 #include "xfs_error.h"
 #include "xfs_trace.h"
 #include "xfs_buf_item.h"
 #include "xfs_dir2.h"
 #include "xfs_log.h"


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

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

 /*
  * Routines used for growing the Btree.
  */
 STATIC int xfs_attr3_leaf_create(struct xfs_da_args *args,
 				 xfs_dablk_t which_block, struct xfs_buf **bpp);
 STATIC int xfs_attr3_leaf_add_work(struct xfs_buf *leaf_buffer,
 				   struct xfs_attr3_icleaf_hdr *ichdr,
 				   struct xfs_da_args *args, int freemap_index);
 STATIC void xfs_attr3_leaf_compact(struct xfs_da_args *args,
 				   struct xfs_attr3_icleaf_hdr *ichdr,
 				   struct xfs_buf *leaf_buffer);
 STATIC void xfs_attr3_leaf_rebalance(xfs_da_state_t *state,
 						   xfs_da_state_blk_t *blk1,
 						   xfs_da_state_blk_t *blk2);
 STATIC int xfs_attr3_leaf_figure_balance(xfs_da_state_t *state,
 			xfs_da_state_blk_t *leaf_blk_1,
 			struct xfs_attr3_icleaf_hdr *ichdr1,
 			xfs_da_state_blk_t *leaf_blk_2,
 			struct xfs_attr3_icleaf_hdr *ichdr2,
 			int *number_entries_in_blk1,
 			int *number_usedbytes_in_blk1);

 /*
  * Utility routines.
  */
 STATIC void xfs_attr3_leaf_moveents(struct xfs_da_args *args,
 			struct xfs_attr_leafblock *src_leaf,
 			struct xfs_attr3_icleaf_hdr *src_ichdr, int src_start,
 			struct xfs_attr_leafblock *dst_leaf,
 			struct xfs_attr3_icleaf_hdr *dst_ichdr, int dst_start,
 			int move_count);
 STATIC int xfs_attr_leaf_entsize(xfs_attr_leafblock_t *leaf, int index);

 /*
  * attr3 block 'firstused' conversion helpers.
  *
  * firstused refers to the offset of the first used byte of the nameval region
  * of an attr leaf block. The region starts at the tail of the block and expands
  * backwards towards the middle. As such, firstused is initialized to the block
  * size for an empty leaf block and is reduced from there.
  *
  * The attr3 block size is pegged to the fsb size and the maximum fsb is 64k.
  * The in-core firstused field is 32-bit and thus supports the maximum fsb size.
  * The on-disk field is only 16-bit, however, and overflows at 64k. Since this
  * only occurs at exactly 64k, we use zero as a magic on-disk value to represent
  * the attr block size. The following helpers manage the conversion between the
  * in-core and on-disk formats.
  */

 static void
 xfs_attr3_leaf_firstused_from_disk(
 	struct xfs_da_geometry		*geo,
 	struct xfs_attr3_icleaf_hdr	*to,
 	struct xfs_attr_leafblock	*from)
 {
 	struct xfs_attr3_leaf_hdr	*hdr3;

 	if (from->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC)) {
 		hdr3 = (struct xfs_attr3_leaf_hdr *) from;
 		to->firstused = be16_to_cpu(hdr3->firstused);
 	} else {
 		to->firstused = be16_to_cpu(from->hdr.firstused);
 	}

 	/*
 	 * Convert from the magic fsb size value to actual blocksize. This
 	 * should only occur for empty blocks when the block size overflows
 	 * 16-bits.
 	 */
 	if (to->firstused == XFS_ATTR3_LEAF_NULLOFF) {
 		ASSERT(!to->count && !to->usedbytes);
 		ASSERT(geo->blksize > USHRT_MAX);
 		to->firstused = geo->blksize;
 	}
 }

 static void
 xfs_attr3_leaf_firstused_to_disk(
 	struct xfs_da_geometry		*geo,
 	struct xfs_attr_leafblock	*to,
 	struct xfs_attr3_icleaf_hdr	*from)
 {
 	struct xfs_attr3_leaf_hdr	*hdr3;
 	uint32_t			firstused;

 	/* magic value should only be seen on disk */
 	ASSERT(from->firstused != XFS_ATTR3_LEAF_NULLOFF);

 	/*
 	 * Scale down the 32-bit in-core firstused value to the 16-bit on-disk
 	 * value. This only overflows at the max supported value of 64k. Use the
 	 * magic on-disk value to represent block size in this case.
 	 */
 	firstused = from->firstused;
 	if (firstused > USHRT_MAX) {
 		ASSERT(from->firstused == geo->blksize);
 		firstused = XFS_ATTR3_LEAF_NULLOFF;
 	}

 	if (from->magic == XFS_ATTR3_LEAF_MAGIC) {
 		hdr3 = (struct xfs_attr3_leaf_hdr *) to;
 		hdr3->firstused = cpu_to_be16(firstused);
 	} else {
 		to->hdr.firstused = cpu_to_be16(firstused);
 	}
 }

 void
 xfs_attr3_leaf_hdr_from_disk(
 	struct xfs_da_geometry		*geo,
 	struct xfs_attr3_icleaf_hdr	*to,
 	struct xfs_attr_leafblock	*from)
 {
 	int	i;

 	ASSERT(from->hdr.info.magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
 	       from->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));

 	if (from->hdr.info.magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC)) {
 		struct xfs_attr3_leaf_hdr *hdr3 = (struct xfs_attr3_leaf_hdr *)from;

 		to->forw = be32_to_cpu(hdr3->info.hdr.forw);
 		to->back = be32_to_cpu(hdr3->info.hdr.back);
 		to->magic = be16_to_cpu(hdr3->info.hdr.magic);
 		to->count = be16_to_cpu(hdr3->count);
 		to->usedbytes = be16_to_cpu(hdr3->usedbytes);
 		xfs_attr3_leaf_firstused_from_disk(geo, to, from);
 		to->holes = hdr3->holes;

 		for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
 			to->freemap[i].base = be16_to_cpu(hdr3->freemap[i].base);
 			to->freemap[i].size = be16_to_cpu(hdr3->freemap[i].size);
 		}
 		return;
 	}
 	to->forw = be32_to_cpu(from->hdr.info.forw);
 	to->back = be32_to_cpu(from->hdr.info.back);
 	to->magic = be16_to_cpu(from->hdr.info.magic);
 	to->count = be16_to_cpu(from->hdr.count);
 	to->usedbytes = be16_to_cpu(from->hdr.usedbytes);
 	xfs_attr3_leaf_firstused_from_disk(geo, to, from);
 	to->holes = from->hdr.holes;

 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
 		to->freemap[i].base = be16_to_cpu(from->hdr.freemap[i].base);
 		to->freemap[i].size = be16_to_cpu(from->hdr.freemap[i].size);
 	}
 }

 void
 xfs_attr3_leaf_hdr_to_disk(
 	struct xfs_da_geometry		*geo,
 	struct xfs_attr_leafblock	*to,
 	struct xfs_attr3_icleaf_hdr	*from)
 {
 	int				i;

 	ASSERT(from->magic == XFS_ATTR_LEAF_MAGIC ||
 	       from->magic == XFS_ATTR3_LEAF_MAGIC);

 	if (from->magic == XFS_ATTR3_LEAF_MAGIC) {
 		struct xfs_attr3_leaf_hdr *hdr3 = (struct xfs_attr3_leaf_hdr *)to;

 		hdr3->info.hdr.forw = cpu_to_be32(from->forw);
 		hdr3->info.hdr.back = cpu_to_be32(from->back);
 		hdr3->info.hdr.magic = cpu_to_be16(from->magic);
 		hdr3->count = cpu_to_be16(from->count);
 		hdr3->usedbytes = cpu_to_be16(from->usedbytes);
 		xfs_attr3_leaf_firstused_to_disk(geo, to, from);
 		hdr3->holes = from->holes;
 		hdr3->pad1 = 0;

 		for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
 			hdr3->freemap[i].base = cpu_to_be16(from->freemap[i].base);
 			hdr3->freemap[i].size = cpu_to_be16(from->freemap[i].size);
 		}
 		return;
 	}
 	to->hdr.info.forw = cpu_to_be32(from->forw);
 	to->hdr.info.back = cpu_to_be32(from->back);
 	to->hdr.info.magic = cpu_to_be16(from->magic);
 	to->hdr.count = cpu_to_be16(from->count);
 	to->hdr.usedbytes = cpu_to_be16(from->usedbytes);
 	xfs_attr3_leaf_firstused_to_disk(geo, to, from);
 	to->hdr.holes = from->holes;
 	to->hdr.pad1 = 0;

 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
 		to->hdr.freemap[i].base = cpu_to_be16(from->freemap[i].base);
 		to->hdr.freemap[i].size = cpu_to_be16(from->freemap[i].size);
 	}
 }

 static xfs_failaddr_t
 xfs_attr3_leaf_verify(
 	struct xfs_buf			*bp)
 {
 	struct xfs_attr3_icleaf_hdr	ichdr;
 	struct xfs_mount		*mp = bp->b_mount;
 	struct xfs_attr_leafblock	*leaf = bp->b_addr;
 	struct xfs_attr_leaf_entry	*entries;
 	uint32_t			end;	/* must be 32bit - see below */
 	int				i;
 	xfs_failaddr_t			fa;

 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);

 	fa = xfs_da3_blkinfo_verify(bp, bp->b_addr);
 	if (fa)
 		return fa;

 	/*
 	 * In recovery there is a transient state where count == 0 is valid
 	 * because we may have transitioned an empty shortform attr to a leaf
 	 * if the attr didn't fit in shortform.
 	 */
 	if (!xfs_log_in_recovery(mp) && ichdr.count == 0)
 		return __this_address;

 	/*
 	 * firstused is the block offset of the first name info structure.
 	 * Make sure it doesn't go off the block or crash into the header.
 	 */
 	if (ichdr.firstused > mp->m_attr_geo->blksize)
 		return __this_address;
 	if (ichdr.firstused < xfs_attr3_leaf_hdr_size(leaf))
 		return __this_address;

 	/* Make sure the entries array doesn't crash into the name info. */
 	entries = xfs_attr3_leaf_entryp(bp->b_addr);
 	if ((char *)&entries[ichdr.count] >
 	    (char *)bp->b_addr + ichdr.firstused)
 		return __this_address;

 	/* XXX: need to range check rest of attr header values */
 	/* XXX: hash order check? */

 	/*
 	 * Quickly check the freemap information.  Attribute data has to be
 	 * aligned to 4-byte boundaries, and likewise for the free space.
 	 *
 	 * Note that for 64k block size filesystems, the freemap entries cannot
 	 * overflow as they are only be16 fields. However, when checking end
 	 * pointer of the freemap, we have to be careful to detect overflows and
 	 * so use uint32_t for those checks.
 	 */
 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
 		if (ichdr.freemap[i].base > mp->m_attr_geo->blksize)
 			return __this_address;
 		if (ichdr.freemap[i].base & 0x3)
 			return __this_address;
 		if (ichdr.freemap[i].size > mp->m_attr_geo->blksize)
 			return __this_address;
 		if (ichdr.freemap[i].size & 0x3)
 			return __this_address;

 		/* be care of 16 bit overflows here */
 		end = (uint32_t)ichdr.freemap[i].base + ichdr.freemap[i].size;
 		if (end < ichdr.freemap[i].base)
 			return __this_address;
 		if (end > mp->m_attr_geo->blksize)
 			return __this_address;
 	}

 	return NULL;
 }

 static void
 xfs_attr3_leaf_write_verify(
 	struct xfs_buf	*bp)
 {
 	struct xfs_mount	*mp = bp->b_mount;
 	struct xfs_buf_log_item	*bip = bp->b_log_item;
 	struct xfs_attr3_leaf_hdr *hdr3 = bp->b_addr;
 	xfs_failaddr_t		fa;

 	fa = xfs_attr3_leaf_verify(bp);
 	if (fa) {
 		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 		return;
 	}

 	if (!xfs_sb_version_hascrc(&mp->m_sb))
 		return;

 	if (bip)
 		hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);

 	xfs_buf_update_cksum(bp, XFS_ATTR3_LEAF_CRC_OFF);
 }

 /*
  * leaf/node format detection on trees is sketchy, so a node read can be done on
  * leaf level blocks when detection identifies the tree as a node format tree
  * incorrectly. In this case, we need to swap the verifier to match the correct
  * format of the block being read.
  */
 static void
 xfs_attr3_leaf_read_verify(
 	struct xfs_buf		*bp)
 {
 	struct xfs_mount	*mp = bp->b_mount;
 	xfs_failaddr_t		fa;

 	if (xfs_sb_version_hascrc(&mp->m_sb) &&
 	     !xfs_buf_verify_cksum(bp, XFS_ATTR3_LEAF_CRC_OFF))
 		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 	else {
 		fa = xfs_attr3_leaf_verify(bp);
 		if (fa)
 			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
 	}
 }

 const struct xfs_buf_ops xfs_attr3_leaf_buf_ops = {
 	.name = "xfs_attr3_leaf",
 	.magic16 = { cpu_to_be16(XFS_ATTR_LEAF_MAGIC),
 		     cpu_to_be16(XFS_ATTR3_LEAF_MAGIC) },
 	.verify_read = xfs_attr3_leaf_read_verify,
 	.verify_write = xfs_attr3_leaf_write_verify,
 	.verify_struct = xfs_attr3_leaf_verify,
 };

 int
 xfs_attr3_leaf_read(
 	struct xfs_trans	*tp,
 	struct xfs_inode	*dp,
 	xfs_dablk_t		bno,
 	xfs_daddr_t		mappedbno,
 	struct xfs_buf		**bpp)
 {
 	int			err;

 	err = xfs_da_read_buf(tp, dp, bno, mappedbno, bpp,
 				XFS_ATTR_FORK, &xfs_attr3_leaf_buf_ops);
 	if (!err && tp && *bpp)
 		xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_ATTR_LEAF_BUF);
 	return err;
 }

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

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

 static int
 xfs_attr_copy_value(
 	struct xfs_da_args	*args,
 	unsigned char		*value,
 	int			valuelen)
 {
 	/*
 	 * No copy if all we have to do is get the length
 	 */
 	if (args->flags & ATTR_KERNOVAL) {
 		args->valuelen = valuelen;
 		return 0;
 	}

 	/*
 	 * No copy if the length of the existing buffer is too small
 	 */
 	if (args->valuelen < valuelen) {
 		args->valuelen = valuelen;
 		return -ERANGE;
 	}

 	if (args->op_flags & XFS_DA_OP_ALLOCVAL) {
 		args->value = kmem_alloc_large(valuelen, 0);
 		if (!args->value)
 			return -ENOMEM;
 	}
 	args->valuelen = valuelen;

 	/* remote block xattr requires IO for copy-in */
 	if (args->rmtblkno)
 		return xfs_attr_rmtval_get(args);

 	/*
 	 * This is to prevent a GCC warning because the remote xattr case
 	 * doesn't have a value to pass in. In that case, we never reach here,
 	 * but GCC can't work that out and so throws a "passing NULL to
 	 * memcpy" warning.
 	 */
 	if (!value)
 		return -EINVAL;
 	memcpy(args->value, value, valuelen);
 	return 0;
 }

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

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

 	/* rounded down */
 	offset = (XFS_LITINO(mp, dp->i_d.di_version) - bytes) >> 3;

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

 	/*
 	 * If the requested numbers of bytes is smaller or equal to the
 	 * current attribute fork size we can always proceed.
 	 *
 	 * Note that if_bytes in the data fork might actually be larger than
 	 * the current data fork size is due to delalloc extents. In that
 	 * case either the extent count will go down when they are converted
 	 * to real extents, or the delalloc conversion will take care of the
 	 * literal area rebalancing.
 	 */
 	if (bytes <= XFS_IFORK_ASIZE(dp))
 		return dp->i_d.di_forkoff;

 	/*
 	 * For attr2 we can try to move the forkoff if there is space in the
 	 * literal area, but for the old format we are done if there is no
 	 * space in the fixed attribute fork.
 	 */
 	if (!(mp->m_flags & XFS_MOUNT_ATTR2))
 		return 0;

 	dsize = dp->i_df.if_bytes;

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

 	/*
 	 * A data fork btree root must have space for at least
 	 * MINDBTPTRS key/ptr pairs if the data fork is small or empty.
 	 */
 	minforkoff = max(dsize, XFS_BMDR_SPACE_CALC(MINDBTPTRS));
 	minforkoff = roundup(minforkoff, 8) >> 3;

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

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

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

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

 	trace_xfs_attr_sf_create(args);

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

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

 	trace_xfs_attr_sf_add(args);

 	dp = args->dp;
 	mp = dp->i_mount;
 	dp->i_d.di_forkoff = forkoff;

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

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

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

 	xfs_sbversion_add_attr2(mp, args->trans);
 }

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

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

 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
 }

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

 	trace_xfs_attr_sf_remove(args);

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

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

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

 	xfs_sbversion_add_attr2(mp, args->trans);

 	return 0;
 }

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

 	trace_xfs_attr_sf_lookup(args);

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

 /*
  * Retreive the attribute value and length.
  *
  * If ATTR_KERNOVAL is specified, only the length needs to be returned.
  * Unlike a lookup, we only return an error if the attribute does not
  * exist or we can't retrieve the value.
  */
 int
 xfs_attr_shortform_getvalue(
 	struct xfs_da_args	*args)
 {
 	struct xfs_attr_shortform *sf;
 	struct xfs_attr_sf_entry *sfe;
 	int			i;

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

 /*
  * Convert from using the shortform to the leaf.  On success, return the
  * buffer so that we can keep it locked until we're totally done with it.
  */
 int
 xfs_attr_shortform_to_leaf(
 	struct xfs_da_args		*args,
 	struct xfs_buf			**leaf_bp)
 {
 	struct xfs_inode		*dp;
 	struct xfs_attr_shortform	*sf;
 	struct xfs_attr_sf_entry	*sfe;
 	struct xfs_da_args		nargs;
 	char				*tmpbuffer;
 	int				error, i, size;
 	xfs_dablk_t			blkno;
 	struct xfs_buf			*bp;
 	struct xfs_ifork		*ifp;

 	trace_xfs_attr_sf_to_leaf(args);

 	dp = args->dp;
 	ifp = dp->i_afp;
 	sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
 	size = be16_to_cpu(sf->hdr.totsize);
 	tmpbuffer = kmem_alloc(size, 0);
 	ASSERT(tmpbuffer != NULL);
 	memcpy(tmpbuffer, ifp->if_u1.if_data, size);
 	sf = (xfs_attr_shortform_t *)tmpbuffer;

 	xfs_idata_realloc(dp, -size, XFS_ATTR_FORK);
 	xfs_bmap_local_to_extents_empty(args->trans, dp, XFS_ATTR_FORK);

 	bp = NULL;
 	error = xfs_da_grow_inode(args, &blkno);
 	if (error)
 		goto out;

 	ASSERT(blkno == 0);
 	error = xfs_attr3_leaf_create(args, blkno, &bp);
 	if (error)
 		goto out;

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

 	sfe = &sf->list[0];
 	for (i = 0; i < sf->hdr.count; i++) {
 		nargs.name = sfe->nameval;
 		nargs.namelen = sfe->namelen;
 		nargs.value = &sfe->nameval[nargs.namelen];
 		nargs.valuelen = sfe->valuelen;
 		nargs.hashval = xfs_da_hashname(sfe->nameval,
 						sfe->namelen);
 		nargs.flags = XFS_ATTR_NSP_ONDISK_TO_ARGS(sfe->flags);
 		error = xfs_attr3_leaf_lookup_int(bp, &nargs); /* set a->index */
 		ASSERT(error == -ENOATTR);
 		error = xfs_attr3_leaf_add(bp, &nargs);
 		ASSERT(error != -ENOSPC);
 		if (error)
 			goto out;
 		sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
 	}
 	error = 0;
 	*leaf_bp = bp;
 out:
 	kmem_free(tmpbuffer);
 	return error;
 }

 /*
  * Check a leaf attribute block to see if all the entries would fit into
  * a shortform attribute list.
  */
 int
 xfs_attr_shortform_allfit(
 	struct xfs_buf		*bp,
 	struct xfs_inode	*dp)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr_leaf_entry *entry;
 	xfs_attr_leaf_name_local_t *name_loc;
 	struct xfs_attr3_icleaf_hdr leafhdr;
 	int			bytes;
 	int			i;
 	struct xfs_mount	*mp = bp->b_mount;

 	leaf = bp->b_addr;
 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
 	entry = xfs_attr3_leaf_entryp(leaf);

 	bytes = sizeof(struct xfs_attr_sf_hdr);
 	for (i = 0; i < leafhdr.count; entry++, i++) {
 		if (entry->flags & XFS_ATTR_INCOMPLETE)
 			continue;		/* don't copy partial entries */
 		if (!(entry->flags & XFS_ATTR_LOCAL))
 			return 0;
 		name_loc = xfs_attr3_leaf_name_local(leaf, i);
 		if (name_loc->namelen >= XFS_ATTR_SF_ENTSIZE_MAX)
 			return 0;
 		if (be16_to_cpu(name_loc->valuelen) >= XFS_ATTR_SF_ENTSIZE_MAX)
 			return 0;
 		bytes += sizeof(struct xfs_attr_sf_entry) - 1
 				+ name_loc->namelen
 				+ be16_to_cpu(name_loc->valuelen);
 	}
 	if ((dp->i_mount->m_flags & XFS_MOUNT_ATTR2) &&
 	    (dp->i_d.di_format != XFS_DINODE_FMT_BTREE) &&
 	    (bytes == sizeof(struct xfs_attr_sf_hdr)))
 		return -1;
 	return xfs_attr_shortform_bytesfit(dp, bytes);
 }

 /* Verify the consistency of an inline attribute fork. */
 xfs_failaddr_t
 xfs_attr_shortform_verify(
 	struct xfs_inode		*ip)
 {
 	struct xfs_attr_shortform	*sfp;
 	struct xfs_attr_sf_entry	*sfep;
 	struct xfs_attr_sf_entry	*next_sfep;
 	char				*endp;
 	struct xfs_ifork		*ifp;
 	int				i;
 	int				size;

 	ASSERT(ip->i_d.di_aformat == XFS_DINODE_FMT_LOCAL);
 	ifp = XFS_IFORK_PTR(ip, XFS_ATTR_FORK);
 	sfp = (struct xfs_attr_shortform *)ifp->if_u1.if_data;
 	size = ifp->if_bytes;

 	/*
 	 * Give up if the attribute is way too short.
 	 */
 	if (size < sizeof(struct xfs_attr_sf_hdr))
 		return __this_address;

 	endp = (char *)sfp + size;

 	/* Check all reported entries */
 	sfep = &sfp->list[0];
 	for (i = 0; i < sfp->hdr.count; i++) {
 		/*
 		 * struct xfs_attr_sf_entry has a variable length.
 		 * Check the fixed-offset parts of the structure are
 		 * within the data buffer.
 		 */
 		if (((char *)sfep + sizeof(*sfep)) >= endp)
 			return __this_address;

 		/* Don't allow names with known bad length. */
 		if (sfep->namelen == 0)
 			return __this_address;

 		/*
 		 * Check that the variable-length part of the structure is
 		 * within the data buffer.  The next entry starts after the
 		 * name component, so nextentry is an acceptable test.
 		 */
 		next_sfep = XFS_ATTR_SF_NEXTENTRY(sfep);
 		if ((char *)next_sfep > endp)
 			return __this_address;

 		/*
 		 * Check for unknown flags.  Short form doesn't support
 		 * the incomplete or local bits, so we can use the namespace
 		 * mask here.
 		 */
 		if (sfep->flags & ~XFS_ATTR_NSP_ONDISK_MASK)
 			return __this_address;

 		/*
 		 * Check for invalid namespace combinations.  We only allow
 		 * one namespace flag per xattr, so we can just count the
 		 * bits (i.e. hweight) here.
 		 */
 		if (hweight8(sfep->flags & XFS_ATTR_NSP_ONDISK_MASK) > 1)
 			return __this_address;

 		sfep = next_sfep;
 	}
 	if ((void *)sfep != (void *)endp)
 		return __this_address;

 	return NULL;
 }

 /*
  * Convert a leaf attribute list to shortform attribute list
  */
 int
 xfs_attr3_leaf_to_shortform(
 	struct xfs_buf		*bp,
 	struct xfs_da_args	*args,
 	int			forkoff)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr3_icleaf_hdr ichdr;
 	struct xfs_attr_leaf_entry *entry;
 	struct xfs_attr_leaf_name_local *name_loc;
 	struct xfs_da_args	nargs;
 	struct xfs_inode	*dp = args->dp;
 	char			*tmpbuffer;
 	int			error;
 	int			i;

 	trace_xfs_attr_leaf_to_sf(args);

 	tmpbuffer = kmem_alloc(args->geo->blksize, 0);
 	if (!tmpbuffer)
 		return -ENOMEM;

 	memcpy(tmpbuffer, bp->b_addr, args->geo->blksize);

 	leaf = (xfs_attr_leafblock_t *)tmpbuffer;
 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
 	entry = xfs_attr3_leaf_entryp(leaf);

 	/* XXX (dgc): buffer is about to be marked stale - why zero it? */
 	memset(bp->b_addr, 0, args->geo->blksize);

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

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

 	xfs_attr_shortform_create(args);

 	/*
 	 * Copy the attributes
 	 */
 	memset((char *)&nargs, 0, sizeof(nargs));
 	nargs.geo = args->geo;
 	nargs.dp = dp;
 	nargs.total = args->total;
 	nargs.whichfork = XFS_ATTR_FORK;
 	nargs.trans = args->trans;
 	nargs.op_flags = XFS_DA_OP_OKNOENT;

 	for (i = 0; i < ichdr.count; entry++, i++) {
 		if (entry->flags & XFS_ATTR_INCOMPLETE)
 			continue;	/* don't copy partial entries */
 		if (!entry->nameidx)
 			continue;
 		ASSERT(entry->flags & XFS_ATTR_LOCAL);
 		name_loc = xfs_attr3_leaf_name_local(leaf, i);
 		nargs.name = name_loc->nameval;
 		nargs.namelen = name_loc->namelen;
 		nargs.value = &name_loc->nameval[nargs.namelen];
 		nargs.valuelen = be16_to_cpu(name_loc->valuelen);
 		nargs.hashval = be32_to_cpu(entry->hashval);
 		nargs.flags = XFS_ATTR_NSP_ONDISK_TO_ARGS(entry->flags);
 		xfs_attr_shortform_add(&nargs, forkoff);
 	}
 	error = 0;

 out:
 	kmem_free(tmpbuffer);
 	return error;
 }

 /*
  * Convert from using a single leaf to a root node and a leaf.
  */
 int
 xfs_attr3_leaf_to_node(
 	struct xfs_da_args	*args)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr3_icleaf_hdr icleafhdr;
 	struct xfs_attr_leaf_entry *entries;
 	struct xfs_da_node_entry *btree;
 	struct xfs_da3_icnode_hdr icnodehdr;
 	struct xfs_da_intnode	*node;
 	struct xfs_inode	*dp = args->dp;
 	struct xfs_mount	*mp = dp->i_mount;
 	struct xfs_buf		*bp1 = NULL;
 	struct xfs_buf		*bp2 = NULL;
 	xfs_dablk_t		blkno;
 	int			error;

 	trace_xfs_attr_leaf_to_node(args);

 	error = xfs_da_grow_inode(args, &blkno);
 	if (error)
 		goto out;
 	error = xfs_attr3_leaf_read(args->trans, dp, 0, -1, &bp1);
 	if (error)
 		goto out;

 	error = xfs_da_get_buf(args->trans, dp, blkno, -1, &bp2, XFS_ATTR_FORK);
 	if (error)
 		goto out;

 	/* copy leaf to new buffer, update identifiers */
 	xfs_trans_buf_set_type(args->trans, bp2, XFS_BLFT_ATTR_LEAF_BUF);
 	bp2->b_ops = bp1->b_ops;
 	memcpy(bp2->b_addr, bp1->b_addr, args->geo->blksize);
 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
 		struct xfs_da3_blkinfo *hdr3 = bp2->b_addr;
 		hdr3->blkno = cpu_to_be64(bp2->b_bn);
 	}
 	xfs_trans_log_buf(args->trans, bp2, 0, args->geo->blksize - 1);

 	/*
 	 * Set up the new root node.
 	 */
 	error = xfs_da3_node_create(args, 0, 1, &bp1, XFS_ATTR_FORK);
 	if (error)
 		goto out;
 	node = bp1->b_addr;
 	dp->d_ops->node_hdr_from_disk(&icnodehdr, node);
 	btree = dp->d_ops->node_tree_p(node);

 	leaf = bp2->b_addr;
 	xfs_attr3_leaf_hdr_from_disk(args->geo, &icleafhdr, leaf);
 	entries = xfs_attr3_leaf_entryp(leaf);

 	/* both on-disk, don't endian-flip twice */
 	btree[0].hashval = entries[icleafhdr.count - 1].hashval;
 	btree[0].before = cpu_to_be32(blkno);
 	icnodehdr.count = 1;
 	dp->d_ops->node_hdr_to_disk(node, &icnodehdr);
 	xfs_trans_log_buf(args->trans, bp1, 0, args->geo->blksize - 1);
 	error = 0;
 out:
 	return error;
 }

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

 /*
  * Create the initial contents of a leaf attribute list
  * or a leaf in a node attribute list.
  */
 STATIC int
 xfs_attr3_leaf_create(
 	struct xfs_da_args	*args,
 	xfs_dablk_t		blkno,
 	struct xfs_buf		**bpp)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr3_icleaf_hdr ichdr;
 	struct xfs_inode	*dp = args->dp;
 	struct xfs_mount	*mp = dp->i_mount;
 	struct xfs_buf		*bp;
 	int			error;

 	trace_xfs_attr_leaf_create(args);

 	error = xfs_da_get_buf(args->trans, args->dp, blkno, -1, &bp,
 					    XFS_ATTR_FORK);
 	if (error)
 		return error;
 	bp->b_ops = &xfs_attr3_leaf_buf_ops;
 	xfs_trans_buf_set_type(args->trans, bp, XFS_BLFT_ATTR_LEAF_BUF);
 	leaf = bp->b_addr;
 	memset(leaf, 0, args->geo->blksize);

 	memset(&ichdr, 0, sizeof(ichdr));
 	ichdr.firstused = args->geo->blksize;

 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
 		struct xfs_da3_blkinfo *hdr3 = bp->b_addr;

 		ichdr.magic = XFS_ATTR3_LEAF_MAGIC;

 		hdr3->blkno = cpu_to_be64(bp->b_bn);
 		hdr3->owner = cpu_to_be64(dp->i_ino);
 		uuid_copy(&hdr3->uuid, &mp->m_sb.sb_meta_uuid);

 		ichdr.freemap[0].base = sizeof(struct xfs_attr3_leaf_hdr);
 	} else {
 		ichdr.magic = XFS_ATTR_LEAF_MAGIC;
 		ichdr.freemap[0].base = sizeof(struct xfs_attr_leaf_hdr);
 	}
 	ichdr.freemap[0].size = ichdr.firstused - ichdr.freemap[0].base;

 	xfs_attr3_leaf_hdr_to_disk(args->geo, leaf, &ichdr);
 	xfs_trans_log_buf(args->trans, bp, 0, args->geo->blksize - 1);

 	*bpp = bp;
 	return 0;
 }

 /*
  * Split the leaf node, rebalance, then add the new entry.
  */
 int
 xfs_attr3_leaf_split(
 	struct xfs_da_state	*state,
 	struct xfs_da_state_blk	*oldblk,
 	struct xfs_da_state_blk	*newblk)
 {
 	xfs_dablk_t blkno;
 	int error;

 	trace_xfs_attr_leaf_split(state->args);

 	/*
 	 * Allocate space for a new leaf node.
 	 */
 	ASSERT(oldblk->magic == XFS_ATTR_LEAF_MAGIC);
 	error = xfs_da_grow_inode(state->args, &blkno);
 	if (error)
 		return error;
 	error = xfs_attr3_leaf_create(state->args, blkno, &newblk->bp);
 	if (error)
 		return error;
 	newblk->blkno = blkno;
 	newblk->magic = XFS_ATTR_LEAF_MAGIC;

 	/*
 	 * Rebalance the entries across the two leaves.
 	 * NOTE: rebalance() currently depends on the 2nd block being empty.
 	 */
 	xfs_attr3_leaf_rebalance(state, oldblk, newblk);
 	error = xfs_da3_blk_link(state, oldblk, newblk);
 	if (error)
 		return error;

 	/*
 	 * Save info on "old" attribute for "atomic rename" ops, leaf_add()
 	 * modifies the index/blkno/rmtblk/rmtblkcnt fields to show the
 	 * "new" attrs info.  Will need the "old" info to remove it later.
 	 *
 	 * Insert the "new" entry in the correct block.
 	 */
 	if (state->inleaf) {
 		trace_xfs_attr_leaf_add_old(state->args);
 		error = xfs_attr3_leaf_add(oldblk->bp, state->args);
 	} else {
 		trace_xfs_attr_leaf_add_new(state->args);
 		error = xfs_attr3_leaf_add(newblk->bp, state->args);
 	}

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

 /*
  * Add a name to the leaf attribute list structure.
  */
 int
 xfs_attr3_leaf_add(
 	struct xfs_buf		*bp,
 	struct xfs_da_args	*args)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr3_icleaf_hdr ichdr;
 	int			tablesize;
 	int			entsize;
 	int			sum;
 	int			tmp;
 	int			i;

 	trace_xfs_attr_leaf_add(args);

 	leaf = bp->b_addr;
 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
 	ASSERT(args->index >= 0 && args->index <= ichdr.count);
 	entsize = xfs_attr_leaf_newentsize(args, NULL);

 	/*
 	 * Search through freemap for first-fit on new name length.
 	 * (may need to figure in size of entry struct too)
 	 */
 	tablesize = (ichdr.count + 1) * sizeof(xfs_attr_leaf_entry_t)
 					+ xfs_attr3_leaf_hdr_size(leaf);
 	for (sum = 0, i = XFS_ATTR_LEAF_MAPSIZE - 1; i >= 0; i--) {
 		if (tablesize > ichdr.firstused) {
 			sum += ichdr.freemap[i].size;
 			continue;
 		}
 		if (!ichdr.freemap[i].size)
 			continue;	/* no space in this map */
 		tmp = entsize;
 		if (ichdr.freemap[i].base < ichdr.firstused)
 			tmp += sizeof(xfs_attr_leaf_entry_t);
 		if (ichdr.freemap[i].size >= tmp) {
 			tmp = xfs_attr3_leaf_add_work(bp, &ichdr, args, i);
 			goto out_log_hdr;
 		}
 		sum += ichdr.freemap[i].size;
 	}

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

 	/*
 	 * Compact the entries to coalesce free space.
 	 * This may change the hdr->count via dropping INCOMPLETE entries.
 	 */
 	xfs_attr3_leaf_compact(args, &ichdr, bp);

 	/*
 	 * After compaction, the block is guaranteed to have only one
 	 * free region, in freemap[0].  If it is not big enough, give up.
 	 */
 	if (ichdr.freemap[0].size < (entsize + sizeof(xfs_attr_leaf_entry_t))) {
 		tmp = -ENOSPC;
 		goto out_log_hdr;
 	}

 	tmp = xfs_attr3_leaf_add_work(bp, &ichdr, args, 0);

 out_log_hdr:
 	xfs_attr3_leaf_hdr_to_disk(args->geo, leaf, &ichdr);
 	xfs_trans_log_buf(args->trans, bp,
 		XFS_DA_LOGRANGE(leaf, &leaf->hdr,
 				xfs_attr3_leaf_hdr_size(leaf)));
 	return tmp;
 }

 /*
  * Add a name to a leaf attribute list structure.
  */
 STATIC int
 xfs_attr3_leaf_add_work(
 	struct xfs_buf		*bp,
 	struct xfs_attr3_icleaf_hdr *ichdr,
 	struct xfs_da_args	*args,
 	int			mapindex)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr_leaf_entry *entry;
 	struct xfs_attr_leaf_name_local *name_loc;
 	struct xfs_attr_leaf_name_remote *name_rmt;
 	struct xfs_mount	*mp;
 	int			tmp;
 	int			i;

 	trace_xfs_attr_leaf_add_work(args);

 	leaf = bp->b_addr;
 	ASSERT(mapindex >= 0 && mapindex < XFS_ATTR_LEAF_MAPSIZE);
 	ASSERT(args->index >= 0 && args->index <= ichdr->count);

 	/*
 	 * Force open some space in the entry array and fill it in.
 	 */
 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];
 	if (args->index < ichdr->count) {
 		tmp  = ichdr->count - args->index;
 		tmp *= sizeof(xfs_attr_leaf_entry_t);
 		memmove(entry + 1, entry, tmp);
 		xfs_trans_log_buf(args->trans, bp,
 		    XFS_DA_LOGRANGE(leaf, entry, tmp + sizeof(*entry)));
 	}
 	ichdr->count++;

 	/*
 	 * Allocate space for the new string (at the end of the run).
 	 */
 	mp = args->trans->t_mountp;
 	ASSERT(ichdr->freemap[mapindex].base < args->geo->blksize);
 	ASSERT((ichdr->freemap[mapindex].base & 0x3) == 0);
 	ASSERT(ichdr->freemap[mapindex].size >=
 		xfs_attr_leaf_newentsize(args, NULL));
 	ASSERT(ichdr->freemap[mapindex].size < args->geo->blksize);
 	ASSERT((ichdr->freemap[mapindex].size & 0x3) == 0);

 	ichdr->freemap[mapindex].size -= xfs_attr_leaf_newentsize(args, &tmp);

 	entry->nameidx = cpu_to_be16(ichdr->freemap[mapindex].base +
 				     ichdr->freemap[mapindex].size);
 	entry->hashval = cpu_to_be32(args->hashval);
 	entry->flags = tmp ? XFS_ATTR_LOCAL : 0;
 	entry->flags |= XFS_ATTR_NSP_ARGS_TO_ONDISK(args->flags);
 	if (args->op_flags & XFS_DA_OP_RENAME) {
 		entry->flags |= XFS_ATTR_INCOMPLETE;
 		if ((args->blkno2 == args->blkno) &&
 		    (args->index2 <= args->index)) {
 			args->index2++;
 		}
 	}
 	xfs_trans_log_buf(args->trans, bp,
 			  XFS_DA_LOGRANGE(leaf, entry, sizeof(*entry)));
 	ASSERT((args->index == 0) ||
 	       (be32_to_cpu(entry->hashval) >= be32_to_cpu((entry-1)->hashval)));
 	ASSERT((args->index == ichdr->count - 1) ||
 	       (be32_to_cpu(entry->hashval) <= be32_to_cpu((entry+1)->hashval)));

 	/*
 	 * For "remote" attribute values, simply note that we need to
 	 * allocate space for the "remote" value.  We can't actually
 	 * allocate the extents in this transaction, and we can't decide
 	 * which blocks they should be as we might allocate more blocks
 	 * as part of this transaction (a split operation for example).
 	 */
 	if (entry->flags & XFS_ATTR_LOCAL) {
 		name_loc = xfs_attr3_leaf_name_local(leaf, args->index);
 		name_loc->namelen = args->namelen;
 		name_loc->valuelen = cpu_to_be16(args->valuelen);
 		memcpy((char *)name_loc->nameval, args->name, args->namelen);
 		memcpy((char *)&name_loc->nameval[args->namelen], args->value,
 				   be16_to_cpu(name_loc->valuelen));
 	} else {
 		name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
 		name_rmt->namelen = args->namelen;
 		memcpy((char *)name_rmt->name, args->name, args->namelen);
 		entry->flags |= XFS_ATTR_INCOMPLETE;
 		/* just in case */
 		name_rmt->valuelen = 0;
 		name_rmt->valueblk = 0;
 		args->rmtblkno = 1;
 		args->rmtblkcnt = xfs_attr3_rmt_blocks(mp, args->valuelen);
 		args->rmtvaluelen = args->valuelen;
 	}
 	xfs_trans_log_buf(args->trans, bp,
 	     XFS_DA_LOGRANGE(leaf, xfs_attr3_leaf_name(leaf, args->index),
 				   xfs_attr_leaf_entsize(leaf, args->index)));

 	/*
 	 * Update the control info for this leaf node
 	 */
 	if (be16_to_cpu(entry->nameidx) < ichdr->firstused)
 		ichdr->firstused = be16_to_cpu(entry->nameidx);

 	ASSERT(ichdr->firstused >= ichdr->count * sizeof(xfs_attr_leaf_entry_t)
 					+ xfs_attr3_leaf_hdr_size(leaf));
 	tmp = (ichdr->count - 1) * sizeof(xfs_attr_leaf_entry_t)
 					+ xfs_attr3_leaf_hdr_size(leaf);

 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
 		if (ichdr->freemap[i].base == tmp) {
 			ichdr->freemap[i].base += sizeof(xfs_attr_leaf_entry_t);
 			ichdr->freemap[i].size -= sizeof(xfs_attr_leaf_entry_t);
 		}
 	}
 	ichdr->usedbytes += xfs_attr_leaf_entsize(leaf, args->index);
 	return 0;
 }

 /*
  * Garbage collect a leaf attribute list block by copying it to a new buffer.
  */
 STATIC void
 xfs_attr3_leaf_compact(
 	struct xfs_da_args	*args,
 	struct xfs_attr3_icleaf_hdr *ichdr_dst,
 	struct xfs_buf		*bp)
 {
 	struct xfs_attr_leafblock *leaf_src;
 	struct xfs_attr_leafblock *leaf_dst;
 	struct xfs_attr3_icleaf_hdr ichdr_src;
 	struct xfs_trans	*trans = args->trans;
 	char			*tmpbuffer;

 	trace_xfs_attr_leaf_compact(args);

 	tmpbuffer = kmem_alloc(args->geo->blksize, 0);
 	memcpy(tmpbuffer, bp->b_addr, args->geo->blksize);
 	memset(bp->b_addr, 0, args->geo->blksize);
 	leaf_src = (xfs_attr_leafblock_t *)tmpbuffer;
 	leaf_dst = bp->b_addr;

 	/*
 	 * Copy the on-disk header back into the destination buffer to ensure
 	 * all the information in the header that is not part of the incore
 	 * header structure is preserved.
 	 */
 	memcpy(bp->b_addr, tmpbuffer, xfs_attr3_leaf_hdr_size(leaf_src));

 	/* Initialise the incore headers */
 	ichdr_src = *ichdr_dst;	/* struct copy */
 	ichdr_dst->firstused = args->geo->blksize;
 	ichdr_dst->usedbytes = 0;
 	ichdr_dst->count = 0;
 	ichdr_dst->holes = 0;
 	ichdr_dst->freemap[0].base = xfs_attr3_leaf_hdr_size(leaf_src);
 	ichdr_dst->freemap[0].size = ichdr_dst->firstused -
 						ichdr_dst->freemap[0].base;

 	/* write the header back to initialise the underlying buffer */
 	xfs_attr3_leaf_hdr_to_disk(args->geo, leaf_dst, ichdr_dst);

 	/*
 	 * Copy all entry's in the same (sorted) order,
 	 * but allocate name/value pairs packed and in sequence.
 	 */
 	xfs_attr3_leaf_moveents(args, leaf_src, &ichdr_src, 0,
 				leaf_dst, ichdr_dst, 0, ichdr_src.count);
 	/*
 	 * this logs the entire buffer, but the caller must write the header
 	 * back to the buffer when it is finished modifying it.
 	 */
 	xfs_trans_log_buf(trans, bp, 0, args->geo->blksize - 1);

 	kmem_free(tmpbuffer);
 }

 /*
  * Compare two leaf blocks "order".
  * Return 0 unless leaf2 should go before leaf1.
  */
 static int
 xfs_attr3_leaf_order(
 	struct xfs_buf	*leaf1_bp,
 	struct xfs_attr3_icleaf_hdr *leaf1hdr,
 	struct xfs_buf	*leaf2_bp,
 	struct xfs_attr3_icleaf_hdr *leaf2hdr)
 {
 	struct xfs_attr_leaf_entry *entries1;
 	struct xfs_attr_leaf_entry *entries2;

 	entries1 = xfs_attr3_leaf_entryp(leaf1_bp->b_addr);
 	entries2 = xfs_attr3_leaf_entryp(leaf2_bp->b_addr);
 	if (leaf1hdr->count > 0 && leaf2hdr->count > 0 &&
 	    ((be32_to_cpu(entries2[0].hashval) <
 	      be32_to_cpu(entries1[0].hashval)) ||
 	     (be32_to_cpu(entries2[leaf2hdr->count - 1].hashval) <
 	      be32_to_cpu(entries1[leaf1hdr->count - 1].hashval)))) {
 		return 1;
 	}
 	return 0;
 }

 int
 xfs_attr_leaf_order(
 	struct xfs_buf	*leaf1_bp,
 	struct xfs_buf	*leaf2_bp)
 {
 	struct xfs_attr3_icleaf_hdr ichdr1;
 	struct xfs_attr3_icleaf_hdr ichdr2;
 	struct xfs_mount *mp = leaf1_bp->b_mount;

 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr1, leaf1_bp->b_addr);
 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr2, leaf2_bp->b_addr);
 	return xfs_attr3_leaf_order(leaf1_bp, &ichdr1, leaf2_bp, &ichdr2);
 }

 /*
  * Redistribute the attribute list entries between two leaf nodes,
  * taking into account the size of the new entry.
  *
  * NOTE: if new block is empty, then it will get the upper half of the
  * old block.  At present, all (one) callers pass in an empty second block.
  *
  * This code adjusts the args->index/blkno and args->index2/blkno2 fields
  * to match what it is doing in splitting the attribute leaf block.  Those
  * values are used in "atomic rename" operations on attributes.  Note that
  * the "new" and "old" values can end up in different blocks.
  */
 STATIC void
 xfs_attr3_leaf_rebalance(
 	struct xfs_da_state	*state,
 	struct xfs_da_state_blk	*blk1,
 	struct xfs_da_state_blk	*blk2)
 {
 	struct xfs_da_args	*args;
 	struct xfs_attr_leafblock *leaf1;
 	struct xfs_attr_leafblock *leaf2;
 	struct xfs_attr3_icleaf_hdr ichdr1;
 	struct xfs_attr3_icleaf_hdr ichdr2;
 	struct xfs_attr_leaf_entry *entries1;
 	struct xfs_attr_leaf_entry *entries2;
 	int			count;
 	int			totallen;
 	int			max;
 	int			space;
 	int			swap;

 	/*
 	 * Set up environment.
 	 */
 	ASSERT(blk1->magic == XFS_ATTR_LEAF_MAGIC);
 	ASSERT(blk2->magic == XFS_ATTR_LEAF_MAGIC);
 	leaf1 = blk1->bp->b_addr;
 	leaf2 = blk2->bp->b_addr;
 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &ichdr1, leaf1);
 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &ichdr2, leaf2);
 	ASSERT(ichdr2.count == 0);
 	args = state->args;

 	trace_xfs_attr_leaf_rebalance(args);

 	/*
 	 * Check ordering of blocks, reverse if it makes things simpler.
 	 *
 	 * NOTE: Given that all (current) callers pass in an empty
 	 * second block, this code should never set "swap".
 	 */
 	swap = 0;
 	if (xfs_attr3_leaf_order(blk1->bp, &ichdr1, blk2->bp, &ichdr2)) {
 		swap(blk1, blk2);

 		/* swap structures rather than reconverting them */
 		swap(ichdr1, ichdr2);

 		leaf1 = blk1->bp->b_addr;
 		leaf2 = blk2->bp->b_addr;
 		swap = 1;
 	}

 	/*
 	 * Examine entries until we reduce the absolute difference in
 	 * byte usage between the two blocks to a minimum.  Then get
 	 * the direction to copy and the number of elements to move.
 	 *
 	 * "inleaf" is true if the new entry should be inserted into blk1.
 	 * If "swap" is also true, then reverse the sense of "inleaf".
 	 */
 	state->inleaf = xfs_attr3_leaf_figure_balance(state, blk1, &ichdr1,
 						      blk2, &ichdr2,
 						      &count, &totallen);
 	if (swap)
 		state->inleaf = !state->inleaf;

 	/*
 	 * Move any entries required from leaf to leaf:
 	 */
 	if (count < ichdr1.count) {
 		/*
 		 * Figure the total bytes to be added to the destination leaf.
 		 */
 		/* number entries being moved */
 		count = ichdr1.count - count;
 		space  = ichdr1.usedbytes - totallen;
 		space += count * sizeof(xfs_attr_leaf_entry_t);

 		/*
 		 * leaf2 is the destination, compact it if it looks tight.
 		 */
 		max  = ichdr2.firstused - xfs_attr3_leaf_hdr_size(leaf1);
 		max -= ichdr2.count * sizeof(xfs_attr_leaf_entry_t);
 		if (space > max)
 			xfs_attr3_leaf_compact(args, &ichdr2, blk2->bp);

 		/*
 		 * Move high entries from leaf1 to low end of leaf2.
 		 */
 		xfs_attr3_leaf_moveents(args, leaf1, &ichdr1,
 				ichdr1.count - count, leaf2, &ichdr2, 0, count);

 	} else if (count > ichdr1.count) {
 		/*
 		 * I assert that since all callers pass in an empty
 		 * second buffer, this code should never execute.
 		 */
 		ASSERT(0);

 		/*
 		 * Figure the total bytes to be added to the destination leaf.
 		 */
 		/* number entries being moved */
 		count -= ichdr1.count;
 		space  = totallen - ichdr1.usedbytes;
 		space += count * sizeof(xfs_attr_leaf_entry_t);

 		/*
 		 * leaf1 is the destination, compact it if it looks tight.
 		 */
 		max  = ichdr1.firstused - xfs_attr3_leaf_hdr_size(leaf1);
 		max -= ichdr1.count * sizeof(xfs_attr_leaf_entry_t);
 		if (space > max)
 			xfs_attr3_leaf_compact(args, &ichdr1, blk1->bp);

 		/*
 		 * Move low entries from leaf2 to high end of leaf1.
 		 */
 		xfs_attr3_leaf_moveents(args, leaf2, &ichdr2, 0, leaf1, &ichdr1,
 					ichdr1.count, count);
 	}

 	xfs_attr3_leaf_hdr_to_disk(state->args->geo, leaf1, &ichdr1);
 	xfs_attr3_leaf_hdr_to_disk(state->args->geo, leaf2, &ichdr2);
 	xfs_trans_log_buf(args->trans, blk1->bp, 0, args->geo->blksize - 1);
 	xfs_trans_log_buf(args->trans, blk2->bp, 0, args->geo->blksize - 1);

 	/*
 	 * Copy out last hashval in each block for B-tree code.
 	 */
 	entries1 = xfs_attr3_leaf_entryp(leaf1);
 	entries2 = xfs_attr3_leaf_entryp(leaf2);
 	blk1->hashval = be32_to_cpu(entries1[ichdr1.count - 1].hashval);
 	blk2->hashval = be32_to_cpu(entries2[ichdr2.count - 1].hashval);

 	/*
 	 * Adjust the expected index for insertion.
 	 * NOTE: this code depends on the (current) situation that the
 	 * second block was originally empty.
 	 *
 	 * If the insertion point moved to the 2nd block, we must adjust
 	 * the index.  We must also track the entry just following the
 	 * new entry for use in an "atomic rename" operation, that entry
 	 * is always the "old" entry and the "new" entry is what we are
 	 * inserting.  The index/blkno fields refer to the "old" entry,
 	 * while the index2/blkno2 fields refer to the "new" entry.
 	 */
 	if (blk1->index > ichdr1.count) {
 		ASSERT(state->inleaf == 0);
 		blk2->index = blk1->index - ichdr1.count;
 		args->index = args->index2 = blk2->index;
 		args->blkno = args->blkno2 = blk2->blkno;
 	} else if (blk1->index == ichdr1.count) {
 		if (state->inleaf) {
 			args->index = blk1->index;
 			args->blkno = blk1->blkno;
 			args->index2 = 0;
 			args->blkno2 = blk2->blkno;
 		} else {
 			/*
 			 * On a double leaf split, the original attr location
 			 * is already stored in blkno2/index2, so don't
 			 * overwrite it overwise we corrupt the tree.
 			 */
 			blk2->index = blk1->index - ichdr1.count;
 			args->index = blk2->index;
 			args->blkno = blk2->blkno;
 			if (!state->extravalid) {
 				/*
 				 * set the new attr location to match the old
 				 * one and let the higher level split code
 				 * decide where in the leaf to place it.
 				 */
 				args->index2 = blk2->index;
 				args->blkno2 = blk2->blkno;
 			}
 		}
 	} else {
 		ASSERT(state->inleaf == 1);
 		args->index = args->index2 = blk1->index;
 		args->blkno = args->blkno2 = blk1->blkno;
 	}
 }

 /*
  * Examine entries until we reduce the absolute difference in
  * byte usage between the two blocks to a minimum.
  * GROT: Is this really necessary?  With other than a 512 byte blocksize,
  * GROT: there will always be enough room in either block for a new entry.
  * GROT: Do a double-split for this case?
  */
 STATIC int
 xfs_attr3_leaf_figure_balance(
 	struct xfs_da_state		*state,
 	struct xfs_da_state_blk		*blk1,
 	struct xfs_attr3_icleaf_hdr	*ichdr1,
 	struct xfs_da_state_blk		*blk2,
 	struct xfs_attr3_icleaf_hdr	*ichdr2,
 	int				*countarg,
 	int				*usedbytesarg)
 {
 	struct xfs_attr_leafblock	*leaf1 = blk1->bp->b_addr;
 	struct xfs_attr_leafblock	*leaf2 = blk2->bp->b_addr;
 	struct xfs_attr_leaf_entry	*entry;
 	int				count;
 	int				max;
 	int				index;
 	int				totallen = 0;
 	int				half;
 	int				lastdelta;
 	int				foundit = 0;
 	int				tmp;

 	/*
 	 * Examine entries until we reduce the absolute difference in
 	 * byte usage between the two blocks to a minimum.
 	 */
 	max = ichdr1->count + ichdr2->count;
 	half = (max + 1) * sizeof(*entry);
 	half += ichdr1->usedbytes + ichdr2->usedbytes +
 			xfs_attr_leaf_newentsize(state->args, NULL);
 	half /= 2;
 	lastdelta = state->args->geo->blksize;
 	entry = xfs_attr3_leaf_entryp(leaf1);
 	for (count = index = 0; count < max; entry++, index++, count++) {

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

 		/*
 		 * Wrap around into the second block if necessary.
 		 */
 		if (count == ichdr1->count) {
 			leaf1 = leaf2;
 			entry = xfs_attr3_leaf_entryp(leaf1);
 			index = 0;
 		}

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

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

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

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

 /*
  * Check a leaf block and its neighbors to see if the block should be
  * collapsed into one or the other neighbor.  Always keep the block
  * with the smaller block number.
  * If the current block is over 50% full, don't try to join it, return 0.
  * If the block is empty, fill in the state structure and return 2.
  * If it can be collapsed, fill in the state structure and return 1.
  * If nothing can be done, return 0.
  *
  * GROT: allow for INCOMPLETE entries in calculation.
  */
 int
 xfs_attr3_leaf_toosmall(
 	struct xfs_da_state	*state,
 	int			*action)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_da_state_blk	*blk;
 	struct xfs_attr3_icleaf_hdr ichdr;
 	struct xfs_buf		*bp;
 	xfs_dablk_t		blkno;
 	int			bytes;
 	int			forward;
 	int			error;
 	int			retval;
 	int			i;

 	trace_xfs_attr_leaf_toosmall(state->args);

 	/*
 	 * 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 ];
 	leaf = blk->bp->b_addr;
 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &ichdr, leaf);
 	bytes = xfs_attr3_leaf_hdr_size(leaf) +
 		ichdr.count * sizeof(xfs_attr_leaf_entry_t) +
 		ichdr.usedbytes;
 	if (bytes > (state->args->geo->blksize >> 1)) {
 		*action = 0;	/* blk over 50%, don't try to join */
 		return 0;
 	}

 	/*
 	 * Check for the degenerate case of the block being empty.
 	 * If the block is empty, we'll simply delete it, no need to
 	 * coalesce it with a sibling block.  We choose (arbitrarily)
 	 * to merge with the forward block unless it is NULL.
 	 */
 	if (ichdr.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 = (ichdr.forw != 0);
 		memcpy(&state->altpath, &state->path, sizeof(state->path));
 		error = xfs_da3_path_shift(state, &state->altpath, forward,
 						 0, &retval);
 		if (error)
 			return error;
 		if (retval) {
 			*action = 0;
 		} else {
 			*action = 2;
 		}
 		return 0;
 	}

 	/*
 	 * Examine each sibling block to see if we can coalesce with
 	 * at least 25% free space to spare.  We need to figure out
 	 * whether to merge with the forward or the backward block.
 	 * We prefer coalescing with the lower numbered sibling so as
 	 * to shrink an attribute list over time.
 	 */
 	/* start with smaller blk num */
 	forward = ichdr.forw < ichdr.back;
 	for (i = 0; i < 2; forward = !forward, i++) {
 		struct xfs_attr3_icleaf_hdr ichdr2;
 		if (forward)
 			blkno = ichdr.forw;
 		else
 			blkno = ichdr.back;
 		if (blkno == 0)
 			continue;
 		error = xfs_attr3_leaf_read(state->args->trans, state->args->dp,
 					blkno, -1, &bp);
 		if (error)
 			return error;

 		xfs_attr3_leaf_hdr_from_disk(state->args->geo, &ichdr2, bp->b_addr);

 		bytes = state->args->geo->blksize -
 			(state->args->geo->blksize >> 2) -
 			ichdr.usedbytes - ichdr2.usedbytes -
 			((ichdr.count + ichdr2.count) *
 					sizeof(xfs_attr_leaf_entry_t)) -
 			xfs_attr3_leaf_hdr_size(leaf);

 		xfs_trans_brelse(state->args->trans, bp);
 		if (bytes >= 0)
 			break;	/* fits with at least 25% to spare */
 	}
 	if (i >= 2) {
 		*action = 0;
 		return 0;
 	}

 	/*
 	 * Make altpath point to the block we want to keep (the lower
 	 * numbered block) and path point to the block we want to drop.
 	 */
 	memcpy(&state->altpath, &state->path, sizeof(state->path));
 	if (blkno < blk->blkno) {
 		error = xfs_da3_path_shift(state, &state->altpath, forward,
 						 0, &retval);
 	} else {
 		error = xfs_da3_path_shift(state, &state->path, forward,
 						 0, &retval);
 	}
 	if (error)
 		return error;
 	if (retval) {
 		*action = 0;
 	} else {
 		*action = 1;
 	}
 	return 0;
 }

 /*
  * Remove a name from the leaf attribute list structure.
  *
  * Return 1 if leaf is less than 37% full, 0 if >= 37% full.
  * If two leaves are 37% full, when combined they will leave 25% free.
  */
 int
 xfs_attr3_leaf_remove(
 	struct xfs_buf		*bp,
 	struct xfs_da_args	*args)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr3_icleaf_hdr ichdr;
 	struct xfs_attr_leaf_entry *entry;
 	int			before;
 	int			after;
 	int			smallest;
 	int			entsize;
 	int			tablesize;
 	int			tmp;
 	int			i;

 	trace_xfs_attr_leaf_remove(args);

 	leaf = bp->b_addr;
 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);

 	ASSERT(ichdr.count > 0 && ichdr.count < args->geo->blksize / 8);
 	ASSERT(args->index >= 0 && args->index < ichdr.count);
 	ASSERT(ichdr.firstused >= ichdr.count * sizeof(*entry) +
 					xfs_attr3_leaf_hdr_size(leaf));

 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];

 	ASSERT(be16_to_cpu(entry->nameidx) >= ichdr.firstused);
 	ASSERT(be16_to_cpu(entry->nameidx) < args->geo->blksize);

 	/*
 	 * Scan through free region table:
 	 *    check for adjacency of free'd entry with an existing one,
 	 *    find smallest free region in case we need to replace it,
 	 *    adjust any map that borders the entry table,
 	 */
 	tablesize = ichdr.count * sizeof(xfs_attr_leaf_entry_t)
 					+ xfs_attr3_leaf_hdr_size(leaf);
 	tmp = ichdr.freemap[0].size;
 	before = after = -1;
 	smallest = XFS_ATTR_LEAF_MAPSIZE - 1;
 	entsize = xfs_attr_leaf_entsize(leaf, args->index);
 	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
 		ASSERT(ichdr.freemap[i].base < args->geo->blksize);
 		ASSERT(ichdr.freemap[i].size < args->geo->blksize);
 		if (ichdr.freemap[i].base == tablesize) {
 			ichdr.freemap[i].base -= sizeof(xfs_attr_leaf_entry_t);
 			ichdr.freemap[i].size += sizeof(xfs_attr_leaf_entry_t);
 		}

 		if (ichdr.freemap[i].base + ichdr.freemap[i].size ==
 				be16_to_cpu(entry->nameidx)) {
 			before = i;
 		} else if (ichdr.freemap[i].base ==
 				(be16_to_cpu(entry->nameidx) + entsize)) {
 			after = i;
 		} else if (ichdr.freemap[i].size < tmp) {
 			tmp = ichdr.freemap[i].size;
 			smallest = i;
 		}
 	}

 	/*
 	 * Coalesce adjacent freemap regions,
 	 * or replace the smallest region.
 	 */
 	if ((before >= 0) || (after >= 0)) {
 		if ((before >= 0) && (after >= 0)) {
 			ichdr.freemap[before].size += entsize;
 			ichdr.freemap[before].size += ichdr.freemap[after].size;
 			ichdr.freemap[after].base = 0;
 			ichdr.freemap[after].size = 0;
 		} else if (before >= 0) {
 			ichdr.freemap[before].size += entsize;
 		} else {
 			ichdr.freemap[after].base = be16_to_cpu(entry->nameidx);
 			ichdr.freemap[after].size += entsize;
 		}
 	} else {
 		/*
 		 * Replace smallest region (if it is smaller than free'd entry)
 		 */
 		if (ichdr.freemap[smallest].size < entsize) {
 			ichdr.freemap[smallest].base = be16_to_cpu(entry->nameidx);
 			ichdr.freemap[smallest].size = entsize;
 		}
 	}

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

 	/*
 	 * Compress the remaining entries and zero out the removed stuff.
 	 */
 	memset(xfs_attr3_leaf_name(leaf, args->index), 0, entsize);
 	ichdr.usedbytes -= entsize;
 	xfs_trans_log_buf(args->trans, bp,
 	     XFS_DA_LOGRANGE(leaf, xfs_attr3_leaf_name(leaf, args->index),
 				   entsize));

 	tmp = (ichdr.count - args->index) * sizeof(xfs_attr_leaf_entry_t);
 	memmove(entry, entry + 1, tmp);
 	ichdr.count--;
 	xfs_trans_log_buf(args->trans, bp,
 	    XFS_DA_LOGRANGE(leaf, entry, tmp + sizeof(xfs_attr_leaf_entry_t)));

 	entry = &xfs_attr3_leaf_entryp(leaf)[ichdr.count];
 	memset(entry, 0, sizeof(xfs_attr_leaf_entry_t));

 	/*
 	 * If we removed the first entry, re-find the first used byte
 	 * in the name area.  Note that if the entry was the "firstused",
 	 * then we don't have a "hole" in our block resulting from
 	 * removing the name.
 	 */
 	if (smallest) {
 		tmp = args->geo->blksize;
 		entry = xfs_attr3_leaf_entryp(leaf);
 		for (i = ichdr.count - 1; i >= 0; entry++, i--) {
 			ASSERT(be16_to_cpu(entry->nameidx) >= ichdr.firstused);
 			ASSERT(be16_to_cpu(entry->nameidx) < args->geo->blksize);

 			if (be16_to_cpu(entry->nameidx) < tmp)
 				tmp = be16_to_cpu(entry->nameidx);
 		}
 		ichdr.firstused = tmp;
 		ASSERT(ichdr.firstused != 0);
 	} else {
 		ichdr.holes = 1;	/* mark as needing compaction */
 	}
 	xfs_attr3_leaf_hdr_to_disk(args->geo, leaf, &ichdr);
 	xfs_trans_log_buf(args->trans, bp,
 			  XFS_DA_LOGRANGE(leaf, &leaf->hdr,
 					  xfs_attr3_leaf_hdr_size(leaf)));

 	/*
 	 * Check if leaf is less than 50% full, caller may want to
 	 * "join" the leaf with a sibling if so.
 	 */
 	tmp = ichdr.usedbytes + xfs_attr3_leaf_hdr_size(leaf) +
 	      ichdr.count * sizeof(xfs_attr_leaf_entry_t);

 	return tmp < args->geo->magicpct; /* leaf is < 37% full */
 }

 /*
  * Move all the attribute list entries from drop_leaf into save_leaf.
  */
 void
 xfs_attr3_leaf_unbalance(
 	struct xfs_da_state	*state,
 	struct xfs_da_state_blk	*drop_blk,
 	struct xfs_da_state_blk	*save_blk)
 {
 	struct xfs_attr_leafblock *drop_leaf = drop_blk->bp->b_addr;
 	struct xfs_attr_leafblock *save_leaf = save_blk->bp->b_addr;
 	struct xfs_attr3_icleaf_hdr drophdr;
 	struct xfs_attr3_icleaf_hdr savehdr;
 	struct xfs_attr_leaf_entry *entry;

 	trace_xfs_attr_leaf_unbalance(state->args);

 	drop_leaf = drop_blk->bp->b_addr;
 	save_leaf = save_blk->bp->b_addr;
 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &drophdr, drop_leaf);
 	xfs_attr3_leaf_hdr_from_disk(state->args->geo, &savehdr, save_leaf);
 	entry = xfs_attr3_leaf_entryp(drop_leaf);

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

 	/*
 	 * Check if we need a temp buffer, or can we do it in place.
 	 * Note that we don't check "leaf" for holes because we will
 	 * always be dropping it, toosmall() decided that for us already.
 	 */
 	if (savehdr.holes == 0) {
 		/*
 		 * dest leaf has no holes, so we add there.  May need
 		 * to make some room in the entry array.
 		 */
 		if (xfs_attr3_leaf_order(save_blk->bp, &savehdr,
 					 drop_blk->bp, &drophdr)) {
 			xfs_attr3_leaf_moveents(state->args,
 						drop_leaf, &drophdr, 0,
 						save_leaf, &savehdr, 0,
 						drophdr.count);
 		} else {
 			xfs_attr3_leaf_moveents(state->args,
 						drop_leaf, &drophdr, 0,
 						save_leaf, &savehdr,
 						savehdr.count, drophdr.count);
 		}
 	} else {
 		/*
 		 * Destination has holes, so we make a temporary copy
 		 * of the leaf and add them both to that.
 		 */
 		struct xfs_attr_leafblock *tmp_leaf;
 		struct xfs_attr3_icleaf_hdr tmphdr;

 		tmp_leaf = kmem_zalloc(state->args->geo->blksize, 0);

 		/*
 		 * Copy the header into the temp leaf so that all the stuff
 		 * not in the incore header is present and gets copied back in
 		 * once we've moved all the entries.
 		 */
 		memcpy(tmp_leaf, save_leaf, xfs_attr3_leaf_hdr_size(save_leaf));

 		memset(&tmphdr, 0, sizeof(tmphdr));
 		tmphdr.magic = savehdr.magic;
 		tmphdr.forw = savehdr.forw;
 		tmphdr.back = savehdr.back;
 		tmphdr.firstused = state->args->geo->blksize;

 		/* write the header to the temp buffer to initialise it */
 		xfs_attr3_leaf_hdr_to_disk(state->args->geo, tmp_leaf, &tmphdr);

 		if (xfs_attr3_leaf_order(save_blk->bp, &savehdr,
 					 drop_blk->bp, &drophdr)) {
 			xfs_attr3_leaf_moveents(state->args,
 						drop_leaf, &drophdr, 0,
 						tmp_leaf, &tmphdr, 0,
 						drophdr.count);
 			xfs_attr3_leaf_moveents(state->args,
 						save_leaf, &savehdr, 0,
 						tmp_leaf, &tmphdr, tmphdr.count,
 						savehdr.count);
 		} else {
 			xfs_attr3_leaf_moveents(state->args,
 						save_leaf, &savehdr, 0,
 						tmp_leaf, &tmphdr, 0,
 						savehdr.count);
 			xfs_attr3_leaf_moveents(state->args,
 						drop_leaf, &drophdr, 0,
 						tmp_leaf, &tmphdr, tmphdr.count,
 						drophdr.count);
 		}
 		memcpy(save_leaf, tmp_leaf, state->args->geo->blksize);
 		savehdr = tmphdr; /* struct copy */
 		kmem_free(tmp_leaf);
 	}

 	xfs_attr3_leaf_hdr_to_disk(state->args->geo, save_leaf, &savehdr);
 	xfs_trans_log_buf(state->args->trans, save_blk->bp, 0,
 					   state->args->geo->blksize - 1);

 	/*
 	 * Copy out last hashval in each block for B-tree code.
 	 */
 	entry = xfs_attr3_leaf_entryp(save_leaf);
 	save_blk->hashval = be32_to_cpu(entry[savehdr.count - 1].hashval);
 }

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

 /*
  * Look up a name in a leaf attribute list structure.
  * This is the internal routine, it uses the caller's buffer.
  *
  * Note that duplicate keys are allowed, but only check within the
  * current leaf node.  The Btree code must check in adjacent leaf nodes.
  *
  * Return in args->index the index into the entry[] array of either
  * the found entry, or where the entry should have been (insert before
  * that entry).
  *
  * Don't change the args->value unless we find the attribute.
  */
 int
 xfs_attr3_leaf_lookup_int(
 	struct xfs_buf		*bp,
 	struct xfs_da_args	*args)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr3_icleaf_hdr ichdr;
 	struct xfs_attr_leaf_entry *entry;
 	struct xfs_attr_leaf_entry *entries;
 	struct xfs_attr_leaf_name_local *name_loc;
 	struct xfs_attr_leaf_name_remote *name_rmt;
 	xfs_dahash_t		hashval;
 	int			probe;
 	int			span;

 	trace_xfs_attr_leaf_lookup(args);

 	leaf = bp->b_addr;
 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
 	entries = xfs_attr3_leaf_entryp(leaf);
 	if (ichdr.count >= args->geo->blksize / 8)
 		return -EFSCORRUPTED;

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

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

 	/*
 	 * Duplicate keys may be present, so search all of them for a match.
 	 */
 	for (; probe < ichdr.count && (be32_to_cpu(entry->hashval) == hashval);
 			entry++, probe++) {
 /*
  * GROT: Add code to remove incomplete entries.
  */
 		/*
 		 * If we are looking for INCOMPLETE entries, show only those.
 		 * If we are looking for complete entries, show only those.
 		 */
 		if ((args->flags & XFS_ATTR_INCOMPLETE) !=
 		    (entry->flags & XFS_ATTR_INCOMPLETE)) {
 			continue;
 		}
 		if (entry->flags & XFS_ATTR_LOCAL) {
 			name_loc = xfs_attr3_leaf_name_local(leaf, probe);
 			if (name_loc->namelen != args->namelen)
 				continue;
 			if (memcmp(args->name, name_loc->nameval,
 							args->namelen) != 0)
 				continue;
 			if (!xfs_attr_namesp_match(args->flags, entry->flags))
 				continue;
 			args->index = probe;
 			return -EEXIST;
 		} else {
 			name_rmt = xfs_attr3_leaf_name_remote(leaf, probe);
 			if (name_rmt->namelen != args->namelen)
 				continue;
 			if (memcmp(args->name, name_rmt->name,
 							args->namelen) != 0)
 				continue;
 			if (!xfs_attr_namesp_match(args->flags, entry->flags))
 				continue;
 			args->index = probe;
 			args->rmtvaluelen = be32_to_cpu(name_rmt->valuelen);
 			args->rmtblkno = be32_to_cpu(name_rmt->valueblk);
 			args->rmtblkcnt = xfs_attr3_rmt_blocks(
 							args->dp->i_mount,
 							args->rmtvaluelen);
 			return -EEXIST;
 		}
 	}
 	args->index = probe;
 	return -ENOATTR;
 }

 /*
  * Get the value associated with an attribute name from a leaf attribute
  * list structure.
  *
  * If ATTR_KERNOVAL is specified, only the length needs to be returned.
  * Unlike a lookup, we only return an error if the attribute does not
  * exist or we can't retrieve the value.
  */
 int
 xfs_attr3_leaf_getvalue(
 	struct xfs_buf		*bp,
 	struct xfs_da_args	*args)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr3_icleaf_hdr ichdr;
 	struct xfs_attr_leaf_entry *entry;
 	struct xfs_attr_leaf_name_local *name_loc;
 	struct xfs_attr_leaf_name_remote *name_rmt;

 	leaf = bp->b_addr;
 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
 	ASSERT(ichdr.count < args->geo->blksize / 8);
 	ASSERT(args->index < ichdr.count);

 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];
 	if (entry->flags & XFS_ATTR_LOCAL) {
 		name_loc = xfs_attr3_leaf_name_local(leaf, args->index);
 		ASSERT(name_loc->namelen == args->namelen);
 		ASSERT(memcmp(args->name, name_loc->nameval, args->namelen) == 0);
 		return xfs_attr_copy_value(args,
 					&name_loc->nameval[args->namelen],
 					be16_to_cpu(name_loc->valuelen));
 	}

 	name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
 	ASSERT(name_rmt->namelen == args->namelen);
 	ASSERT(memcmp(args->name, name_rmt->name, args->namelen) == 0);
 	args->rmtvaluelen = be32_to_cpu(name_rmt->valuelen);
 	args->rmtblkno = be32_to_cpu(name_rmt->valueblk);
 	args->rmtblkcnt = xfs_attr3_rmt_blocks(args->dp->i_mount,
 					       args->rmtvaluelen);
 	return xfs_attr_copy_value(args, NULL, args->rmtvaluelen);
 }

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

 /*
  * Move the indicated entries from one leaf to another.
  * NOTE: this routine modifies both source and destination leaves.
  */
 /*ARGSUSED*/
 STATIC void
 xfs_attr3_leaf_moveents(
 	struct xfs_da_args		*args,
 	struct xfs_attr_leafblock	*leaf_s,
 	struct xfs_attr3_icleaf_hdr	*ichdr_s,
 	int				start_s,
 	struct xfs_attr_leafblock	*leaf_d,
 	struct xfs_attr3_icleaf_hdr	*ichdr_d,
 	int				start_d,
 	int				count)
 {
 	struct xfs_attr_leaf_entry	*entry_s;
 	struct xfs_attr_leaf_entry	*entry_d;
 	int				desti;
 	int				tmp;
 	int				i;

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

 	/*
 	 * Set up environment.
 	 */
 	ASSERT(ichdr_s->magic == XFS_ATTR_LEAF_MAGIC ||
 	       ichdr_s->magic == XFS_ATTR3_LEAF_MAGIC);
 	ASSERT(ichdr_s->magic == ichdr_d->magic);
 	ASSERT(ichdr_s->count > 0 && ichdr_s->count < args->geo->blksize / 8);
 	ASSERT(ichdr_s->firstused >= (ichdr_s->count * sizeof(*entry_s))
 					+ xfs_attr3_leaf_hdr_size(leaf_s));
 	ASSERT(ichdr_d->count < args->geo->blksize / 8);
 	ASSERT(ichdr_d->firstused >= (ichdr_d->count * sizeof(*entry_d))
 					+ xfs_attr3_leaf_hdr_size(leaf_d));

 	ASSERT(start_s < ichdr_s->count);
 	ASSERT(start_d <= ichdr_d->count);
 	ASSERT(count <= ichdr_s->count);


 	/*
 	 * Move the entries in the destination leaf up to make a hole?
 	 */
 	if (start_d < ichdr_d->count) {
 		tmp  = ichdr_d->count - start_d;
 		tmp *= sizeof(xfs_attr_leaf_entry_t);
 		entry_s = &xfs_attr3_leaf_entryp(leaf_d)[start_d];
 		entry_d = &xfs_attr3_leaf_entryp(leaf_d)[start_d + count];
 		memmove(entry_d, entry_s, tmp);
 	}

 	/*
 	 * Copy all entry's in the same (sorted) order,
 	 * but allocate attribute info packed and in sequence.
 	 */
 	entry_s = &xfs_attr3_leaf_entryp(leaf_s)[start_s];
 	entry_d = &xfs_attr3_leaf_entryp(leaf_d)[start_d];
 	desti = start_d;
 	for (i = 0; i < count; entry_s++, entry_d++, desti++, i++) {
 		ASSERT(be16_to_cpu(entry_s->nameidx) >= ichdr_s->firstused);
 		tmp = xfs_attr_leaf_entsize(leaf_s, start_s + i);
 #ifdef GROT
 		/*
 		 * Code to drop INCOMPLETE entries.  Difficult to use as we
 		 * may also need to change the insertion index.  Code turned
 		 * off for 6.2, should be revisited later.
 		 */
 		if (entry_s->flags & XFS_ATTR_INCOMPLETE) { /* skip partials? */
 			memset(xfs_attr3_leaf_name(leaf_s, start_s + i), 0, tmp);
 			ichdr_s->usedbytes -= tmp;
 			ichdr_s->count -= 1;
 			entry_d--;	/* to compensate for ++ in loop hdr */
 			desti--;
 			if ((start_s + i) < offset)
 				result++;	/* insertion index adjustment */
 		} else {
 #endif /* GROT */
 			ichdr_d->firstused -= tmp;
 			/* both on-disk, don't endian flip twice */
 			entry_d->hashval = entry_s->hashval;
 			entry_d->nameidx = cpu_to_be16(ichdr_d->firstused);
 			entry_d->flags = entry_s->flags;
 			ASSERT(be16_to_cpu(entry_d->nameidx) + tmp
 							<= args->geo->blksize);
 			memmove(xfs_attr3_leaf_name(leaf_d, desti),
 				xfs_attr3_leaf_name(leaf_s, start_s + i), tmp);
 			ASSERT(be16_to_cpu(entry_s->nameidx) + tmp
 							<= args->geo->blksize);
 			memset(xfs_attr3_leaf_name(leaf_s, start_s + i), 0, tmp);
 			ichdr_s->usedbytes -= tmp;
 			ichdr_d->usedbytes += tmp;
 			ichdr_s->count -= 1;
 			ichdr_d->count += 1;
 			tmp = ichdr_d->count * sizeof(xfs_attr_leaf_entry_t)
 					+ xfs_attr3_leaf_hdr_size(leaf_d);
 			ASSERT(ichdr_d->firstused >= tmp);
 #ifdef GROT
 		}
 #endif /* GROT */
 	}

 	/*
 	 * Zero out the entries we just copied.
 	 */
 	if (start_s == ichdr_s->count) {
 		tmp = count * sizeof(xfs_attr_leaf_entry_t);
 		entry_s = &xfs_attr3_leaf_entryp(leaf_s)[start_s];
 		ASSERT(((char *)entry_s + tmp) <=
 		       ((char *)leaf_s + args->geo->blksize));
 		memset(entry_s, 0, tmp);
 	} else {
 		/*
 		 * Move the remaining entries down to fill the hole,
 		 * then zero the entries at the top.
 		 */
 		tmp  = (ichdr_s->count - count) * sizeof(xfs_attr_leaf_entry_t);
 		entry_s = &xfs_attr3_leaf_entryp(leaf_s)[start_s + count];
 		entry_d = &xfs_attr3_leaf_entryp(leaf_s)[start_s];
 		memmove(entry_d, entry_s, tmp);

 		tmp = count * sizeof(xfs_attr_leaf_entry_t);
 		entry_s = &xfs_attr3_leaf_entryp(leaf_s)[ichdr_s->count];
 		ASSERT(((char *)entry_s + tmp) <=
 		       ((char *)leaf_s + args->geo->blksize));
 		memset(entry_s, 0, tmp);
 	}

 	/*
 	 * Fill in the freemap information
 	 */
 	ichdr_d->freemap[0].base = xfs_attr3_leaf_hdr_size(leaf_d);
 	ichdr_d->freemap[0].base += ichdr_d->count * sizeof(xfs_attr_leaf_entry_t);
 	ichdr_d->freemap[0].size = ichdr_d->firstused - ichdr_d->freemap[0].base;
 	ichdr_d->freemap[1].base = 0;
 	ichdr_d->freemap[2].base = 0;
 	ichdr_d->freemap[1].size = 0;
 	ichdr_d->freemap[2].size = 0;
 	ichdr_s->holes = 1;	/* leaf may not be compact */
 }

 /*
  * Pick up the last hashvalue from a leaf block.
  */
 xfs_dahash_t
 xfs_attr_leaf_lasthash(
 	struct xfs_buf	*bp,
 	int		*count)
 {
 	struct xfs_attr3_icleaf_hdr ichdr;
 	struct xfs_attr_leaf_entry *entries;
 	struct xfs_mount *mp = bp->b_mount;

 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, bp->b_addr);
 	entries = xfs_attr3_leaf_entryp(bp->b_addr);
 	if (count)
 		*count = ichdr.count;
 	if (!ichdr.count)
 		return 0;
 	return be32_to_cpu(entries[ichdr.count - 1].hashval);
 }

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

 	entries = xfs_attr3_leaf_entryp(leaf);
 	if (entries[index].flags & XFS_ATTR_LOCAL) {
 		name_loc = xfs_attr3_leaf_name_local(leaf, index);
 		size = xfs_attr_leaf_entsize_local(name_loc->namelen,
 						   be16_to_cpu(name_loc->valuelen));
 	} else {
 		name_rmt = xfs_attr3_leaf_name_remote(leaf, index);
 		size = xfs_attr_leaf_entsize_remote(name_rmt->namelen);
 	}
 	return size;
 }

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

 	size = xfs_attr_leaf_entsize_local(args->namelen, args->valuelen);
 	if (size < xfs_attr_leaf_entsize_local_max(args->geo->blksize)) {
 		if (local)
 			*local = 1;
 		return size;
 	}
 	if (local)
 		*local = 0;
 	return xfs_attr_leaf_entsize_remote(args->namelen);
 }


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

 /*
  * Clear the INCOMPLETE flag on an entry in a leaf block.
  */
 int
 xfs_attr3_leaf_clearflag(
 	struct xfs_da_args	*args)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr_leaf_entry *entry;
 	struct xfs_attr_leaf_name_remote *name_rmt;
 	struct xfs_buf		*bp;
 	int			error;
 #ifdef DEBUG
 	struct xfs_attr3_icleaf_hdr ichdr;
 	xfs_attr_leaf_name_local_t *name_loc;
 	int namelen;
 	char *name;
 #endif /* DEBUG */

 	trace_xfs_attr_leaf_clearflag(args);
 	/*
 	 * Set up the operation.
 	 */
 	error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
 	if (error)
 		return error;

 	leaf = bp->b_addr;
 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];
 	ASSERT(entry->flags & XFS_ATTR_INCOMPLETE);

 #ifdef DEBUG
 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
 	ASSERT(args->index < ichdr.count);
 	ASSERT(args->index >= 0);

 	if (entry->flags & XFS_ATTR_LOCAL) {
 		name_loc = xfs_attr3_leaf_name_local(leaf, args->index);
 		namelen = name_loc->namelen;
 		name = (char *)name_loc->nameval;
 	} else {
 		name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
 		namelen = name_rmt->namelen;
 		name = (char *)name_rmt->name;
 	}
 	ASSERT(be32_to_cpu(entry->hashval) == args->hashval);
 	ASSERT(namelen == args->namelen);
 	ASSERT(memcmp(name, args->name, namelen) == 0);
 #endif /* DEBUG */

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

 	if (args->rmtblkno) {
 		ASSERT((entry->flags & XFS_ATTR_LOCAL) == 0);
 		name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
 		name_rmt->valueblk = cpu_to_be32(args->rmtblkno);
 		name_rmt->valuelen = cpu_to_be32(args->rmtvaluelen);
 		xfs_trans_log_buf(args->trans, bp,
 			 XFS_DA_LOGRANGE(leaf, name_rmt, sizeof(*name_rmt)));
 	}

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

 /*
  * Set the INCOMPLETE flag on an entry in a leaf block.
  */
 int
 xfs_attr3_leaf_setflag(
 	struct xfs_da_args	*args)
 {
 	struct xfs_attr_leafblock *leaf;
 	struct xfs_attr_leaf_entry *entry;
 	struct xfs_attr_leaf_name_remote *name_rmt;
 	struct xfs_buf		*bp;
 	int error;
 #ifdef DEBUG
 	struct xfs_attr3_icleaf_hdr ichdr;
 #endif

 	trace_xfs_attr_leaf_setflag(args);

 	/*
 	 * Set up the operation.
 	 */
 	error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
 	if (error)
 		return error;

 	leaf = bp->b_addr;
 #ifdef DEBUG
 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr, leaf);
 	ASSERT(args->index < ichdr.count);
 	ASSERT(args->index >= 0);
 #endif
 	entry = &xfs_attr3_leaf_entryp(leaf)[args->index];

 	ASSERT((entry->flags & XFS_ATTR_INCOMPLETE) == 0);
 	entry->flags |= XFS_ATTR_INCOMPLETE;
 	xfs_trans_log_buf(args->trans, bp,
 			XFS_DA_LOGRANGE(leaf, entry, sizeof(*entry)));
 	if ((entry->flags & XFS_ATTR_LOCAL) == 0) {
 		name_rmt = xfs_attr3_leaf_name_remote(leaf, args->index);
 		name_rmt->valueblk = 0;
 		name_rmt->valuelen = 0;
 		xfs_trans_log_buf(args->trans, bp,
 			 XFS_DA_LOGRANGE(leaf, name_rmt, sizeof(*name_rmt)));
 	}

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

 /*
  * In a single transaction, clear the INCOMPLETE flag on the leaf entry
  * given by args->blkno/index and set the INCOMPLETE flag on the leaf
  * entry given by args->blkno2/index2.
  *
  * Note that they could be in different blocks, or in the same block.
  */
 int
 xfs_attr3_leaf_flipflags(
 	struct xfs_da_args	*args)
 {
 	struct xfs_attr_leafblock *leaf1;
 	struct xfs_attr_leafblock *leaf2;
 	struct xfs_attr_leaf_entry *entry1;
 	struct xfs_attr_leaf_entry *entry2;
 	struct xfs_attr_leaf_name_remote *name_rmt;
 	struct xfs_buf		*bp1;
 	struct xfs_buf		*bp2;
 	int error;
 #ifdef DEBUG
 	struct xfs_attr3_icleaf_hdr ichdr1;
 	struct xfs_attr3_icleaf_hdr ichdr2;
 	xfs_attr_leaf_name_local_t *name_loc;
 	int namelen1, namelen2;
 	char *name1, *name2;
 #endif /* DEBUG */

 	trace_xfs_attr_leaf_flipflags(args);

 	/*
 	 * Read the block containing the "old" attr
 	 */
 	error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno, -1, &bp1);
 	if (error)
 		return error;

 	/*
 	 * Read the block containing the "new" attr, if it is different
 	 */
 	if (args->blkno2 != args->blkno) {
 		error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno2,
 					   -1, &bp2);
 		if (error)
 			return error;
 	} else {
 		bp2 = bp1;
 	}

 	leaf1 = bp1->b_addr;
 	entry1 = &xfs_attr3_leaf_entryp(leaf1)[args->index];

 	leaf2 = bp2->b_addr;
 	entry2 = &xfs_attr3_leaf_entryp(leaf2)[args->index2];

 #ifdef DEBUG
 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr1, leaf1);
 	ASSERT(args->index < ichdr1.count);
 	ASSERT(args->index >= 0);

 	xfs_attr3_leaf_hdr_from_disk(args->geo, &ichdr2, leaf2);
 	ASSERT(args->index2 < ichdr2.count);
 	ASSERT(args->index2 >= 0);

 	if (entry1->flags & XFS_ATTR_LOCAL) {
 		name_loc = xfs_attr3_leaf_name_local(leaf1, args->index);
 		namelen1 = name_loc->namelen;
 		name1 = (char *)name_loc->nameval;
 	} else {
 		name_rmt = xfs_attr3_leaf_name_remote(leaf1, args->index);
 		namelen1 = name_rmt->namelen;
 		name1 = (char *)name_rmt->name;
 	}
 	if (entry2->flags & XFS_ATTR_LOCAL) {
 		name_loc = xfs_attr3_leaf_name_local(leaf2, args->index2);
 		namelen2 = name_loc->namelen;
 		name2 = (char *)name_loc->nameval;
 	} else {
 		name_rmt = xfs_attr3_leaf_name_remote(leaf2, args->index2);
 		namelen2 = name_rmt->namelen;
 		name2 = (char *)name_rmt->name;
 	}
 	ASSERT(be32_to_cpu(entry1->hashval) == be32_to_cpu(entry2->hashval));
 	ASSERT(namelen1 == namelen2);
 	ASSERT(memcmp(name1, name2, namelen1) == 0);
 #endif /* DEBUG */

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

 	entry1->flags &= ~XFS_ATTR_INCOMPLETE;
 	xfs_trans_log_buf(args->trans, bp1,
 			  XFS_DA_LOGRANGE(leaf1, entry1, sizeof(*entry1)));
 	if (args->rmtblkno) {
 		ASSERT((entry1->flags & XFS_ATTR_LOCAL) == 0);
 		name_rmt = xfs_attr3_leaf_name_remote(leaf1, args->index);
 		name_rmt->valueblk = cpu_to_be32(args->rmtblkno);
 		name_rmt->valuelen = cpu_to_be32(args->rmtvaluelen);
 		xfs_trans_log_buf(args->trans, bp1,
 			 XFS_DA_LOGRANGE(leaf1, name_rmt, sizeof(*name_rmt)));
 	}

 	entry2->flags |= XFS_ATTR_INCOMPLETE;
 	xfs_trans_log_buf(args->trans, bp2,
 			  XFS_DA_LOGRANGE(leaf2, entry2, sizeof(*entry2)));
 	if ((entry2->flags & XFS_ATTR_LOCAL) == 0) {
 		name_rmt = xfs_attr3_leaf_name_remote(leaf2, args->index2);
 		name_rmt->valueblk = 0;
 		name_rmt->valuelen = 0;
 		xfs_trans_log_buf(args->trans, bp2,
 			 XFS_DA_LOGRANGE(leaf2, name_rmt, sizeof(*name_rmt)));
 	}

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

 	return error;
 }