Initial import

1 files changed, 5945 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
new file mode 100644
index 000000000..f1026e86d
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -0,0 +1,5945 @@
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_sb.h"
+#include "xfs_mount.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir2.h"
+#include "xfs_inode.h"
+#include "xfs_btree.h"
+#include "xfs_trans.h"
+#include "xfs_inode_item.h"
+#include "xfs_extfree_item.h"
+#include "xfs_alloc.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_rtalloc.h"
+#include "xfs_error.h"
+#include "xfs_quota.h"
+#include "xfs_trans_space.h"
+#include "xfs_buf_item.h"
+#include "xfs_trace.h"
+#include "xfs_symlink.h"
+#include "xfs_attr_leaf.h"
+#include "xfs_filestream.h"
+
+
+kmem_zone_t		*xfs_bmap_free_item_zone;
+
+/*
+ * Miscellaneous helper functions
+ */
+
+/*
+ * Compute and fill in the value of the maximum depth of a bmap btree
+ * in this filesystem.  Done once, during mount.
+ */
+void
+xfs_bmap_compute_maxlevels(
+	xfs_mount_t	*mp,		/* file system mount structure */
+	int		whichfork)	/* data or attr fork */
+{
+	int		level;		/* btree level */
+	uint		maxblocks;	/* max blocks at this level */
+	uint		maxleafents;	/* max leaf entries possible */
+	int		maxrootrecs;	/* max records in root block */
+	int		minleafrecs;	/* min records in leaf block */
+	int		minnoderecs;	/* min records in node block */
+	int		sz;		/* root block size */
+
+	/*
+	 * The maximum number of extents in a file, hence the maximum
+	 * number of leaf entries, is controlled by the type of di_nextents
+	 * (a signed 32-bit number, xfs_extnum_t), or by di_anextents
+	 * (a signed 16-bit number, xfs_aextnum_t).
+	 *
+	 * Note that we can no longer assume that if we are in ATTR1 that
+	 * the fork offset of all the inodes will be
+	 * (xfs_default_attroffset(ip) >> 3) because we could have mounted
+	 * with ATTR2 and then mounted back with ATTR1, keeping the
+	 * di_forkoff's fixed but probably at various positions. Therefore,
+	 * for both ATTR1 and ATTR2 we have to assume the worst case scenario
+	 * of a minimum size available.
+	 */
+	if (whichfork == XFS_DATA_FORK) {
+		maxleafents = MAXEXTNUM;
+		sz = XFS_BMDR_SPACE_CALC(MINDBTPTRS);
+	} else {
+		maxleafents = MAXAEXTNUM;
+		sz = XFS_BMDR_SPACE_CALC(MINABTPTRS);
+	}
+	maxrootrecs = xfs_bmdr_maxrecs(sz, 0);
+	minleafrecs = mp->m_bmap_dmnr[0];
+	minnoderecs = mp->m_bmap_dmnr[1];
+	maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
+	for (level = 1; maxblocks > 1; level++) {
+		if (maxblocks <= maxrootrecs)
+			maxblocks = 1;
+		else
+			maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
+	}
+	mp->m_bm_maxlevels[whichfork] = level;
+}
+
+STATIC int				/* error */
+xfs_bmbt_lookup_eq(
+	struct xfs_btree_cur	*cur,
+	xfs_fileoff_t		off,
+	xfs_fsblock_t		bno,
+	xfs_filblks_t		len,
+	int			*stat)	/* success/failure */
+{
+	cur->bc_rec.b.br_startoff = off;
+	cur->bc_rec.b.br_startblock = bno;
+	cur->bc_rec.b.br_blockcount = len;
+	return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
+}
+
+STATIC int				/* error */
+xfs_bmbt_lookup_ge(
+	struct xfs_btree_cur	*cur,
+	xfs_fileoff_t		off,
+	xfs_fsblock_t		bno,
+	xfs_filblks_t		len,
+	int			*stat)	/* success/failure */
+{
+	cur->bc_rec.b.br_startoff = off;
+	cur->bc_rec.b.br_startblock = bno;
+	cur->bc_rec.b.br_blockcount = len;
+	return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
+}
+
+/*
+ * Check if the inode needs to be converted to btree format.
+ */
+static inline bool xfs_bmap_needs_btree(struct xfs_inode *ip, int whichfork)
+{
+	return XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_EXTENTS &&
+		XFS_IFORK_NEXTENTS(ip, whichfork) >
+			XFS_IFORK_MAXEXT(ip, whichfork);
+}
+
+/*
+ * Check if the inode should be converted to extent format.
+ */
+static inline bool xfs_bmap_wants_extents(struct xfs_inode *ip, int whichfork)
+{
+	return XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_BTREE &&
+		XFS_IFORK_NEXTENTS(ip, whichfork) <=
+			XFS_IFORK_MAXEXT(ip, whichfork);
+}
+
+/*
+ * Update the record referred to by cur to the value given
+ * by [off, bno, len, state].
+ * This either works (return 0) or gets an EFSCORRUPTED error.
+ */
+STATIC int
+xfs_bmbt_update(
+	struct xfs_btree_cur	*cur,
+	xfs_fileoff_t		off,
+	xfs_fsblock_t		bno,
+	xfs_filblks_t		len,
+	xfs_exntst_t		state)
+{
+	union xfs_btree_rec	rec;
+
+	xfs_bmbt_disk_set_allf(&rec.bmbt, off, bno, len, state);
+	return xfs_btree_update(cur, &rec);
+}
+
+/*
+ * Compute the worst-case number of indirect blocks that will be used
+ * for ip's delayed extent of length "len".
+ */
+STATIC xfs_filblks_t
+xfs_bmap_worst_indlen(
+	xfs_inode_t	*ip,		/* incore inode pointer */
+	xfs_filblks_t	len)		/* delayed extent length */
+{
+	int		level;		/* btree level number */
+	int		maxrecs;	/* maximum record count at this level */
+	xfs_mount_t	*mp;		/* mount structure */
+	xfs_filblks_t	rval;		/* return value */
+
+	mp = ip->i_mount;
+	maxrecs = mp->m_bmap_dmxr[0];
+	for (level = 0, rval = 0;
+	     level < XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK);
+	     level++) {
+		len += maxrecs - 1;
+		do_div(len, maxrecs);
+		rval += len;
+		if (len == 1)
+			return rval + XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) -
+				level - 1;
+		if (level == 0)
+			maxrecs = mp->m_bmap_dmxr[1];
+	}
+	return rval;
+}
+
+/*
+ * Calculate the default attribute fork offset for newly created inodes.
+ */
+uint
+xfs_default_attroffset(
+	struct xfs_inode	*ip)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	uint			offset;
+
+	if (mp->m_sb.sb_inodesize == 256) {
+		offset = XFS_LITINO(mp, ip->i_d.di_version) -
+				XFS_BMDR_SPACE_CALC(MINABTPTRS);
+	} else {
+		offset = XFS_BMDR_SPACE_CALC(6 * MINABTPTRS);
+	}
+
+	ASSERT(offset < XFS_LITINO(mp, ip->i_d.di_version));
+	return offset;
+}
+
+/*
+ * Helper routine to reset inode di_forkoff field when switching
+ * attribute fork from local to extent format - we reset it where
+ * possible to make space available for inline data fork extents.
+ */
+STATIC void
+xfs_bmap_forkoff_reset(
+	xfs_inode_t	*ip,
+	int		whichfork)
+{
+	if (whichfork == XFS_ATTR_FORK &&
+	    ip->i_d.di_format != XFS_DINODE_FMT_DEV &&
+	    ip->i_d.di_format != XFS_DINODE_FMT_UUID &&
+	    ip->i_d.di_format != XFS_DINODE_FMT_BTREE) {
+		uint	dfl_forkoff = xfs_default_attroffset(ip) >> 3;
+
+		if (dfl_forkoff > ip->i_d.di_forkoff)
+			ip->i_d.di_forkoff = dfl_forkoff;
+	}
+}
+
+#ifdef DEBUG
+STATIC struct xfs_buf *
+xfs_bmap_get_bp(
+	struct xfs_btree_cur	*cur,
+	xfs_fsblock_t		bno)
+{
+	struct xfs_log_item_desc *lidp;
+	int			i;
+
+	if (!cur)
+		return NULL;
+
+	for (i = 0; i < XFS_BTREE_MAXLEVELS; i++) {
+		if (!cur->bc_bufs[i])
+			break;
+		if (XFS_BUF_ADDR(cur->bc_bufs[i]) == bno)
+			return cur->bc_bufs[i];
+	}
+
+	/* Chase down all the log items to see if the bp is there */
+	list_for_each_entry(lidp, &cur->bc_tp->t_items, lid_trans) {
+		struct xfs_buf_log_item	*bip;
+		bip = (struct xfs_buf_log_item *)lidp->lid_item;
+		if (bip->bli_item.li_type == XFS_LI_BUF &&
+		    XFS_BUF_ADDR(bip->bli_buf) == bno)
+			return bip->bli_buf;
+	}
+
+	return NULL;
+}
+
+STATIC void
+xfs_check_block(
+	struct xfs_btree_block	*block,
+	xfs_mount_t		*mp,
+	int			root,
+	short			sz)
+{
+	int			i, j, dmxr;
+	__be64			*pp, *thispa;	/* pointer to block address */
+	xfs_bmbt_key_t		*prevp, *keyp;
+
+	ASSERT(be16_to_cpu(block->bb_level) > 0);
+
+	prevp = NULL;
+	for( i = 1; i <= xfs_btree_get_numrecs(block); i++) {
+		dmxr = mp->m_bmap_dmxr[0];
+		keyp = XFS_BMBT_KEY_ADDR(mp, block, i);
+
+		if (prevp) {
+			ASSERT(be64_to_cpu(prevp->br_startoff) <
+			       be64_to_cpu(keyp->br_startoff));
+		}
+		prevp = keyp;
+
+		/*
+		 * Compare the block numbers to see if there are dups.
+		 */
+		if (root)
+			pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, i, sz);
+		else
+			pp = XFS_BMBT_PTR_ADDR(mp, block, i, dmxr);
+
+		for (j = i+1; j <= be16_to_cpu(block->bb_numrecs); j++) {
+			if (root)
+				thispa = XFS_BMAP_BROOT_PTR_ADDR(mp, block, j, sz);
+			else
+				thispa = XFS_BMBT_PTR_ADDR(mp, block, j, dmxr);
+			if (*thispa == *pp) {
+				xfs_warn(mp, "%s: thispa(%d) == pp(%d) %Ld",
+					__func__, j, i,
+					(unsigned long long)be64_to_cpu(*thispa));
+				panic("%s: ptrs are equal in node\n",
+					__func__);
+			}
+		}
+	}
+}
+
+/*
+ * Check that the extents for the inode ip are in the right order in all
+ * btree leaves.
+ */
+
+STATIC void
+xfs_bmap_check_leaf_extents(
+	xfs_btree_cur_t		*cur,	/* btree cursor or null */
+	xfs_inode_t		*ip,		/* incore inode pointer */
+	int			whichfork)	/* data or attr fork */
+{
+	struct xfs_btree_block	*block;	/* current btree block */
+	xfs_fsblock_t		bno;	/* block # of "block" */
+	xfs_buf_t		*bp;	/* buffer for "block" */
+	int			error;	/* error return value */
+	xfs_extnum_t		i=0, j;	/* index into the extents list */
+	xfs_ifork_t		*ifp;	/* fork structure */
+	int			level;	/* btree level, for checking */
+	xfs_mount_t		*mp;	/* file system mount structure */
+	__be64			*pp;	/* pointer to block address */
+	xfs_bmbt_rec_t		*ep;	/* pointer to current extent */
+	xfs_bmbt_rec_t		last = {0, 0}; /* last extent in prev block */
+	xfs_bmbt_rec_t		*nextp;	/* pointer to next extent */
+	int			bp_release = 0;
+
+	if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE) {
+		return;
+	}
+
+	bno = NULLFSBLOCK;
+	mp = ip->i_mount;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	block = ifp->if_broot;
+	/*
+	 * Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
+	 */
+	level = be16_to_cpu(block->bb_level);
+	ASSERT(level > 0);
+	xfs_check_block(block, mp, 1, ifp->if_broot_bytes);
+	pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, 1, ifp->if_broot_bytes);
+	bno = be64_to_cpu(*pp);
+
+	ASSERT(bno != NULLFSBLOCK);
+	ASSERT(XFS_FSB_TO_AGNO(mp, bno) < mp->m_sb.sb_agcount);
+	ASSERT(XFS_FSB_TO_AGBNO(mp, bno) < mp->m_sb.sb_agblocks);
+
+	/*
+	 * Go down the tree until leaf level is reached, following the first
+	 * pointer (leftmost) at each level.
+	 */
+	while (level-- > 0) {
+		/* See if buf is in cur first */
+		bp_release = 0;
+		bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
+		if (!bp) {
+			bp_release = 1;
+			error = xfs_btree_read_bufl(mp, NULL, bno, 0, &bp,
+						XFS_BMAP_BTREE_REF,
+						&xfs_bmbt_buf_ops);
+			if (error)
+				goto error_norelse;
+		}
+		block = XFS_BUF_TO_BLOCK(bp);
+		if (level == 0)
+			break;
+
+		/*
+		 * Check this block for basic sanity (increasing keys and
+		 * no duplicate blocks).
+		 */
+
+		xfs_check_block(block, mp, 0, 0);
+		pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
+		bno = be64_to_cpu(*pp);
+		XFS_WANT_CORRUPTED_GOTO(mp,
+					XFS_FSB_SANITY_CHECK(mp, bno), error0);
+		if (bp_release) {
+			bp_release = 0;
+			xfs_trans_brelse(NULL, bp);
+		}
+	}
+
+	/*
+	 * Here with bp and block set to the leftmost leaf node in the tree.
+	 */
+	i = 0;
+
+	/*
+	 * Loop over all leaf nodes checking that all extents are in the right order.
+	 */
+	for (;;) {
+		xfs_fsblock_t	nextbno;
+		xfs_extnum_t	num_recs;
+
+
+		num_recs = xfs_btree_get_numrecs(block);
+
+		/*
+		 * Read-ahead the next leaf block, if any.
+		 */
+
+		nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
+
+		/*
+		 * Check all the extents to make sure they are OK.
+		 * If we had a previous block, the last entry should
+		 * conform with the first entry in this one.
+		 */
+
+		ep = XFS_BMBT_REC_ADDR(mp, block, 1);
+		if (i) {
+			ASSERT(xfs_bmbt_disk_get_startoff(&last) +
+			       xfs_bmbt_disk_get_blockcount(&last) <=
+			       xfs_bmbt_disk_get_startoff(ep));
+		}
+		for (j = 1; j < num_recs; j++) {
+			nextp = XFS_BMBT_REC_ADDR(mp, block, j + 1);
+			ASSERT(xfs_bmbt_disk_get_startoff(ep) +
+			       xfs_bmbt_disk_get_blockcount(ep) <=
+			       xfs_bmbt_disk_get_startoff(nextp));
+			ep = nextp;
+		}
+
+		last = *ep;
+		i += num_recs;
+		if (bp_release) {
+			bp_release = 0;
+			xfs_trans_brelse(NULL, bp);
+		}
+		bno = nextbno;
+		/*
+		 * If we've reached the end, stop.
+		 */
+		if (bno == NULLFSBLOCK)
+			break;
+
+		bp_release = 0;
+		bp = xfs_bmap_get_bp(cur, XFS_FSB_TO_DADDR(mp, bno));
+		if (!bp) {
+			bp_release = 1;
+			error = xfs_btree_read_bufl(mp, NULL, bno, 0, &bp,
+						XFS_BMAP_BTREE_REF,
+						&xfs_bmbt_buf_ops);
+			if (error)
+				goto error_norelse;
+		}
+		block = XFS_BUF_TO_BLOCK(bp);
+	}
+	if (bp_release) {
+		bp_release = 0;
+		xfs_trans_brelse(NULL, bp);
+	}
+	return;
+
+error0:
+	xfs_warn(mp, "%s: at error0", __func__);
+	if (bp_release)
+		xfs_trans_brelse(NULL, bp);
+error_norelse:
+	xfs_warn(mp, "%s: BAD after btree leaves for %d extents",
+		__func__, i);
+	panic("%s: CORRUPTED BTREE OR SOMETHING", __func__);
+	return;
+}
+
+/*
+ * Add bmap trace insert entries for all the contents of the extent records.
+ */
+void
+xfs_bmap_trace_exlist(
+	xfs_inode_t	*ip,		/* incore inode pointer */
+	xfs_extnum_t	cnt,		/* count of entries in the list */
+	int		whichfork,	/* data or attr fork */
+	unsigned long	caller_ip)
+{
+	xfs_extnum_t	idx;		/* extent record index */
+	xfs_ifork_t	*ifp;		/* inode fork pointer */
+	int		state = 0;
+
+	if (whichfork == XFS_ATTR_FORK)
+		state |= BMAP_ATTRFORK;
+
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	ASSERT(cnt == (ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t)));
+	for (idx = 0; idx < cnt; idx++)
+		trace_xfs_extlist(ip, idx, whichfork, caller_ip);
+}
+
+/*
+ * Validate that the bmbt_irecs being returned from bmapi are valid
+ * given the caller's original parameters.  Specifically check the
+ * ranges of the returned irecs to ensure that they only extend beyond
+ * the given parameters if the XFS_BMAPI_ENTIRE flag was set.
+ */
+STATIC void
+xfs_bmap_validate_ret(
+	xfs_fileoff_t		bno,
+	xfs_filblks_t		len,
+	int			flags,
+	xfs_bmbt_irec_t		*mval,
+	int			nmap,
+	int			ret_nmap)
+{
+	int			i;		/* index to map values */
+
+	ASSERT(ret_nmap <= nmap);
+
+	for (i = 0; i < ret_nmap; i++) {
+		ASSERT(mval[i].br_blockcount > 0);
+		if (!(flags & XFS_BMAPI_ENTIRE)) {
+			ASSERT(mval[i].br_startoff >= bno);
+			ASSERT(mval[i].br_blockcount <= len);
+			ASSERT(mval[i].br_startoff + mval[i].br_blockcount <=
+			       bno + len);
+		} else {
+			ASSERT(mval[i].br_startoff < bno + len);
+			ASSERT(mval[i].br_startoff + mval[i].br_blockcount >
+			       bno);
+		}
+		ASSERT(i == 0 ||
+		       mval[i - 1].br_startoff + mval[i - 1].br_blockcount ==
+		       mval[i].br_startoff);
+		ASSERT(mval[i].br_startblock != DELAYSTARTBLOCK &&
+		       mval[i].br_startblock != HOLESTARTBLOCK);
+		ASSERT(mval[i].br_state == XFS_EXT_NORM ||
+		       mval[i].br_state == XFS_EXT_UNWRITTEN);
+	}
+}
+
+#else
+#define xfs_bmap_check_leaf_extents(cur, ip, whichfork)		do { } while (0)
+#define	xfs_bmap_validate_ret(bno,len,flags,mval,onmap,nmap)
+#endif /* DEBUG */
+
+/*
+ * bmap free list manipulation functions
+ */
+
+/*
+ * Add the extent to the list of extents to be free at transaction end.
+ * The list is maintained sorted (by block number).
+ */
+void
+xfs_bmap_add_free(
+	xfs_fsblock_t		bno,		/* fs block number of extent */
+	xfs_filblks_t		len,		/* length of extent */
+	xfs_bmap_free_t		*flist,		/* list of extents */
+	xfs_mount_t		*mp)		/* mount point structure */
+{
+	xfs_bmap_free_item_t	*cur;		/* current (next) element */
+	xfs_bmap_free_item_t	*new;		/* new element */
+	xfs_bmap_free_item_t	*prev;		/* previous element */
+#ifdef DEBUG
+	xfs_agnumber_t		agno;
+	xfs_agblock_t		agbno;
+
+	ASSERT(bno != NULLFSBLOCK);
+	ASSERT(len > 0);
+	ASSERT(len <= MAXEXTLEN);
+	ASSERT(!isnullstartblock(bno));
+	agno = XFS_FSB_TO_AGNO(mp, bno);
+	agbno = XFS_FSB_TO_AGBNO(mp, bno);
+	ASSERT(agno < mp->m_sb.sb_agcount);
+	ASSERT(agbno < mp->m_sb.sb_agblocks);
+	ASSERT(len < mp->m_sb.sb_agblocks);
+	ASSERT(agbno + len <= mp->m_sb.sb_agblocks);
+#endif
+	ASSERT(xfs_bmap_free_item_zone != NULL);
+	new = kmem_zone_alloc(xfs_bmap_free_item_zone, KM_SLEEP);
+	new->xbfi_startblock = bno;
+	new->xbfi_blockcount = (xfs_extlen_t)len;
+	for (prev = NULL, cur = flist->xbf_first;
+	     cur != NULL;
+	     prev = cur, cur = cur->xbfi_next) {
+		if (cur->xbfi_startblock >= bno)
+			break;
+	}
+	if (prev)
+		prev->xbfi_next = new;
+	else
+		flist->xbf_first = new;
+	new->xbfi_next = cur;
+	flist->xbf_count++;
+}
+
+/*
+ * Remove the entry "free" from the free item list.  Prev points to the
+ * previous entry, unless "free" is the head of the list.
+ */
+void
+xfs_bmap_del_free(
+	xfs_bmap_free_t		*flist,	/* free item list header */
+	xfs_bmap_free_item_t	*prev,	/* previous item on list, if any */
+	xfs_bmap_free_item_t	*free)	/* list item to be freed */
+{
+	if (prev)
+		prev->xbfi_next = free->xbfi_next;
+	else
+		flist->xbf_first = free->xbfi_next;
+	flist->xbf_count--;
+	kmem_zone_free(xfs_bmap_free_item_zone, free);
+}
+
+/*
+ * Free up any items left in the list.
+ */
+void
+xfs_bmap_cancel(
+	xfs_bmap_free_t		*flist)	/* list of bmap_free_items */
+{
+	xfs_bmap_free_item_t	*free;	/* free list item */
+	xfs_bmap_free_item_t	*next;
+
+	if (flist->xbf_count == 0)
+		return;
+	ASSERT(flist->xbf_first != NULL);
+	for (free = flist->xbf_first; free; free = next) {
+		next = free->xbfi_next;
+		xfs_bmap_del_free(flist, NULL, free);
+	}
+	ASSERT(flist->xbf_count == 0);
+}
+
+/*
+ * Inode fork format manipulation functions
+ */
+
+/*
+ * Transform a btree format file with only one leaf node, where the
+ * extents list will fit in the inode, into an extents format file.
+ * Since the file extents are already in-core, all we have to do is
+ * give up the space for the btree root and pitch the leaf block.
+ */
+STATIC int				/* error */
+xfs_bmap_btree_to_extents(
+	xfs_trans_t		*tp,	/* transaction pointer */
+	xfs_inode_t		*ip,	/* incore inode pointer */
+	xfs_btree_cur_t		*cur,	/* btree cursor */
+	int			*logflagsp, /* inode logging flags */
+	int			whichfork)  /* data or attr fork */
+{
+	/* REFERENCED */
+	struct xfs_btree_block	*cblock;/* child btree block */
+	xfs_fsblock_t		cbno;	/* child block number */
+	xfs_buf_t		*cbp;	/* child block's buffer */
+	int			error;	/* error return value */
+	xfs_ifork_t		*ifp;	/* inode fork data */
+	xfs_mount_t		*mp;	/* mount point structure */
+	__be64			*pp;	/* ptr to block address */
+	struct xfs_btree_block	*rblock;/* root btree block */
+
+	mp = ip->i_mount;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	ASSERT(ifp->if_flags & XFS_IFEXTENTS);
+	ASSERT(XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_BTREE);
+	rblock = ifp->if_broot;
+	ASSERT(be16_to_cpu(rblock->bb_level) == 1);
+	ASSERT(be16_to_cpu(rblock->bb_numrecs) == 1);
+	ASSERT(xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0) == 1);
+	pp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, ifp->if_broot_bytes);
+	cbno = be64_to_cpu(*pp);
+	*logflagsp = 0;
+#ifdef DEBUG
+	if ((error = xfs_btree_check_lptr(cur, cbno, 1)))
+		return error;
+#endif
+	error = xfs_btree_read_bufl(mp, tp, cbno, 0, &cbp, XFS_BMAP_BTREE_REF,
+				&xfs_bmbt_buf_ops);
+	if (error)
+		return error;
+	cblock = XFS_BUF_TO_BLOCK(cbp);
+	if ((error = xfs_btree_check_block(cur, cblock, 0, cbp)))
+		return error;
+	xfs_bmap_add_free(cbno, 1, cur->bc_private.b.flist, mp);
+	ip->i_d.di_nblocks--;
+	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
+	xfs_trans_binval(tp, cbp);
+	if (cur->bc_bufs[0] == cbp)
+		cur->bc_bufs[0] = NULL;
+	xfs_iroot_realloc(ip, -1, whichfork);
+	ASSERT(ifp->if_broot == NULL);
+	ASSERT((ifp->if_flags & XFS_IFBROOT) == 0);
+	XFS_IFORK_FMT_SET(ip, whichfork, XFS_DINODE_FMT_EXTENTS);
+	*logflagsp = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
+	return 0;
+}
+
+/*
+ * Convert an extents-format file into a btree-format file.
+ * The new file will have a root block (in the inode) and a single child block.
+ */
+STATIC int					/* error */
+xfs_bmap_extents_to_btree(
+	xfs_trans_t		*tp,		/* transaction pointer */
+	xfs_inode_t		*ip,		/* incore inode pointer */
+	xfs_fsblock_t		*firstblock,	/* first-block-allocated */
+	xfs_bmap_free_t		*flist,		/* blocks freed in xaction */
+	xfs_btree_cur_t		**curp,		/* cursor returned to caller */
+	int			wasdel,		/* converting a delayed alloc */
+	int			*logflagsp,	/* inode logging flags */
+	int			whichfork)	/* data or attr fork */
+{
+	struct xfs_btree_block	*ablock;	/* allocated (child) bt block */
+	xfs_buf_t		*abp;		/* buffer for ablock */
+	xfs_alloc_arg_t		args;		/* allocation arguments */
+	xfs_bmbt_rec_t		*arp;		/* child record pointer */
+	struct xfs_btree_block	*block;		/* btree root block */
+	xfs_btree_cur_t		*cur;		/* bmap btree cursor */
+	xfs_bmbt_rec_host_t	*ep;		/* extent record pointer */
+	int			error;		/* error return value */
+	xfs_extnum_t		i, cnt;		/* extent record index */
+	xfs_ifork_t		*ifp;		/* inode fork pointer */
+	xfs_bmbt_key_t		*kp;		/* root block key pointer */
+	xfs_mount_t		*mp;		/* mount structure */
+	xfs_extnum_t		nextents;	/* number of file extents */
+	xfs_bmbt_ptr_t		*pp;		/* root block address pointer */
+
+	mp = ip->i_mount;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	ASSERT(XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_EXTENTS);
+
+	/*
+	 * Make space in the inode incore.
+	 */
+	xfs_iroot_realloc(ip, 1, whichfork);
+	ifp->if_flags |= XFS_IFBROOT;
+
+	/*
+	 * Fill in the root.
+	 */
+	block = ifp->if_broot;
+	if (xfs_sb_version_hascrc(&mp->m_sb))
+		xfs_btree_init_block_int(mp, block, XFS_BUF_DADDR_NULL,
+				 XFS_BMAP_CRC_MAGIC, 1, 1, ip->i_ino,
+				 XFS_BTREE_LONG_PTRS | XFS_BTREE_CRC_BLOCKS);
+	else
+		xfs_btree_init_block_int(mp, block, XFS_BUF_DADDR_NULL,
+				 XFS_BMAP_MAGIC, 1, 1, ip->i_ino,
+				 XFS_BTREE_LONG_PTRS);
+
+	/*
+	 * Need a cursor.  Can't allocate until bb_level is filled in.
+	 */
+	cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
+	cur->bc_private.b.firstblock = *firstblock;
+	cur->bc_private.b.flist = flist;
+	cur->bc_private.b.flags = wasdel ? XFS_BTCUR_BPRV_WASDEL : 0;
+	/*
+	 * Convert to a btree with two levels, one record in root.
+	 */
+	XFS_IFORK_FMT_SET(ip, whichfork, XFS_DINODE_FMT_BTREE);
+	memset(&args, 0, sizeof(args));
+	args.tp = tp;
+	args.mp = mp;
+	args.firstblock = *firstblock;
+	if (*firstblock == NULLFSBLOCK) {
+		args.type = XFS_ALLOCTYPE_START_BNO;
+		args.fsbno = XFS_INO_TO_FSB(mp, ip->i_ino);
+	} else if (flist->xbf_low) {
+		args.type = XFS_ALLOCTYPE_START_BNO;
+		args.fsbno = *firstblock;
+	} else {
+		args.type = XFS_ALLOCTYPE_NEAR_BNO;
+		args.fsbno = *firstblock;
+	}
+	args.minlen = args.maxlen = args.prod = 1;
+	args.wasdel = wasdel;
+	*logflagsp = 0;
+	if ((error = xfs_alloc_vextent(&args))) {
+		xfs_iroot_realloc(ip, -1, whichfork);
+		xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+		return error;
+	}
+	/*
+	 * Allocation can't fail, the space was reserved.
+	 */
+	ASSERT(args.fsbno != NULLFSBLOCK);
+	ASSERT(*firstblock == NULLFSBLOCK ||
+	       args.agno == XFS_FSB_TO_AGNO(mp, *firstblock) ||
+	       (flist->xbf_low &&
+		args.agno > XFS_FSB_TO_AGNO(mp, *firstblock)));
+	*firstblock = cur->bc_private.b.firstblock = args.fsbno;
+	cur->bc_private.b.allocated++;
+	ip->i_d.di_nblocks++;
+	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, 1L);
+	abp = xfs_btree_get_bufl(mp, tp, args.fsbno, 0);
+	/*
+	 * Fill in the child block.
+	 */
+	abp->b_ops = &xfs_bmbt_buf_ops;
+	ablock = XFS_BUF_TO_BLOCK(abp);
+	if (xfs_sb_version_hascrc(&mp->m_sb))
+		xfs_btree_init_block_int(mp, ablock, abp->b_bn,
+				XFS_BMAP_CRC_MAGIC, 0, 0, ip->i_ino,
+				XFS_BTREE_LONG_PTRS | XFS_BTREE_CRC_BLOCKS);
+	else
+		xfs_btree_init_block_int(mp, ablock, abp->b_bn,
+				XFS_BMAP_MAGIC, 0, 0, ip->i_ino,
+				XFS_BTREE_LONG_PTRS);
+
+	arp = XFS_BMBT_REC_ADDR(mp, ablock, 1);
+	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	for (cnt = i = 0; i < nextents; i++) {
+		ep = xfs_iext_get_ext(ifp, i);
+		if (!isnullstartblock(xfs_bmbt_get_startblock(ep))) {
+			arp->l0 = cpu_to_be64(ep->l0);
+			arp->l1 = cpu_to_be64(ep->l1);
+			arp++; cnt++;
+		}
+	}
+	ASSERT(cnt == XFS_IFORK_NEXTENTS(ip, whichfork));
+	xfs_btree_set_numrecs(ablock, cnt);
+
+	/*
+	 * Fill in the root key and pointer.
+	 */
+	kp = XFS_BMBT_KEY_ADDR(mp, block, 1);
+	arp = XFS_BMBT_REC_ADDR(mp, ablock, 1);
+	kp->br_startoff = cpu_to_be64(xfs_bmbt_disk_get_startoff(arp));
+	pp = XFS_BMBT_PTR_ADDR(mp, block, 1, xfs_bmbt_get_maxrecs(cur,
+						be16_to_cpu(block->bb_level)));
+	*pp = cpu_to_be64(args.fsbno);
+
+	/*
+	 * Do all this logging at the end so that
+	 * the root is at the right level.
+	 */
+	xfs_btree_log_block(cur, abp, XFS_BB_ALL_BITS);
+	xfs_btree_log_recs(cur, abp, 1, be16_to_cpu(ablock->bb_numrecs));
+	ASSERT(*curp == NULL);
+	*curp = cur;
+	*logflagsp = XFS_ILOG_CORE | xfs_ilog_fbroot(whichfork);
+	return 0;
+}
+
+/*
+ * Convert a local file to an extents file.
+ * This code is out of bounds for data forks of regular files,
+ * since the file data needs to get logged so things will stay consistent.
+ * (The bmap-level manipulations are ok, though).
+ */
+void
+xfs_bmap_local_to_extents_empty(
+	struct xfs_inode	*ip,
+	int			whichfork)
+{
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+
+	ASSERT(XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL);
+	ASSERT(ifp->if_bytes == 0);
+	ASSERT(XFS_IFORK_NEXTENTS(ip, whichfork) == 0);
+
+	xfs_bmap_forkoff_reset(ip, whichfork);
+	ifp->if_flags &= ~XFS_IFINLINE;
+	ifp->if_flags |= XFS_IFEXTENTS;
+	XFS_IFORK_FMT_SET(ip, whichfork, XFS_DINODE_FMT_EXTENTS);
+}
+
+
+STATIC int				/* error */
+xfs_bmap_local_to_extents(
+	xfs_trans_t	*tp,		/* transaction pointer */
+	xfs_inode_t	*ip,		/* incore inode pointer */
+	xfs_fsblock_t	*firstblock,	/* first block allocated in xaction */
+	xfs_extlen_t	total,		/* total blocks needed by transaction */
+	int		*logflagsp,	/* inode logging flags */
+	int		whichfork,
+	void		(*init_fn)(struct xfs_trans *tp,
+				   struct xfs_buf *bp,
+				   struct xfs_inode *ip,
+				   struct xfs_ifork *ifp))
+{
+	int		error = 0;
+	int		flags;		/* logging flags returned */
+	xfs_ifork_t	*ifp;		/* inode fork pointer */
+	xfs_alloc_arg_t	args;		/* allocation arguments */
+	xfs_buf_t	*bp;		/* buffer for extent block */
+	xfs_bmbt_rec_host_t *ep;	/* extent record pointer */
+
+	/*
+	 * We don't want to deal with the case of keeping inode data inline yet.
+	 * So sending the data fork of a regular inode is invalid.
+	 */
+	ASSERT(!(S_ISREG(ip->i_d.di_mode) && whichfork == XFS_DATA_FORK));
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	ASSERT(XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL);
+
+	if (!ifp->if_bytes) {
+		xfs_bmap_local_to_extents_empty(ip, whichfork);
+		flags = XFS_ILOG_CORE;
+		goto done;
+	}
+
+	flags = 0;
+	error = 0;
+	ASSERT((ifp->if_flags & (XFS_IFINLINE|XFS_IFEXTENTS|XFS_IFEXTIREC)) ==
+								XFS_IFINLINE);
+	memset(&args, 0, sizeof(args));
+	args.tp = tp;
+	args.mp = ip->i_mount;
+	args.firstblock = *firstblock;
+	/*
+	 * Allocate a block.  We know we need only one, since the
+	 * file currently fits in an inode.
+	 */
+	if (*firstblock == NULLFSBLOCK) {
+		args.fsbno = XFS_INO_TO_FSB(args.mp, ip->i_ino);
+		args.type = XFS_ALLOCTYPE_START_BNO;
+	} else {
+		args.fsbno = *firstblock;
+		args.type = XFS_ALLOCTYPE_NEAR_BNO;
+	}
+	args.total = total;
+	args.minlen = args.maxlen = args.prod = 1;
+	error = xfs_alloc_vextent(&args);
+	if (error)
+		goto done;
+
+	/* Can't fail, the space was reserved. */
+	ASSERT(args.fsbno != NULLFSBLOCK);
+	ASSERT(args.len == 1);
+	*firstblock = args.fsbno;
+	bp = xfs_btree_get_bufl(args.mp, tp, args.fsbno, 0);
+
+	/*
+	 * Initialise the block and copy the data
+	 *
+	 * Note: init_fn must set the buffer log item type correctly!
+	 */
+	init_fn(tp, bp, ip, ifp);
+
+	/* account for the change in fork size and log everything */
+	xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
+	xfs_idata_realloc(ip, -ifp->if_bytes, whichfork);
+	xfs_bmap_local_to_extents_empty(ip, whichfork);
+	flags |= XFS_ILOG_CORE;
+
+	xfs_iext_add(ifp, 0, 1);
+	ep = xfs_iext_get_ext(ifp, 0);
+	xfs_bmbt_set_allf(ep, 0, args.fsbno, 1, XFS_EXT_NORM);
+	trace_xfs_bmap_post_update(ip, 0,
+			whichfork == XFS_ATTR_FORK ? BMAP_ATTRFORK : 0,
+			_THIS_IP_);
+	XFS_IFORK_NEXT_SET(ip, whichfork, 1);
+	ip->i_d.di_nblocks = 1;
+	xfs_trans_mod_dquot_byino(tp, ip,
+		XFS_TRANS_DQ_BCOUNT, 1L);
+	flags |= xfs_ilog_fext(whichfork);
+
+done:
+	*logflagsp = flags;
+	return error;
+}
+
+/*
+ * Called from xfs_bmap_add_attrfork to handle btree format files.
+ */
+STATIC int					/* error */
+xfs_bmap_add_attrfork_btree(
+	xfs_trans_t		*tp,		/* transaction pointer */
+	xfs_inode_t		*ip,		/* incore inode pointer */
+	xfs_fsblock_t		*firstblock,	/* first block allocated */
+	xfs_bmap_free_t		*flist,		/* blocks to free at commit */
+	int			*flags)		/* inode logging flags */
+{
+	xfs_btree_cur_t		*cur;		/* btree cursor */
+	int			error;		/* error return value */
+	xfs_mount_t		*mp;		/* file system mount struct */
+	int			stat;		/* newroot status */
+
+	mp = ip->i_mount;
+	if (ip->i_df.if_broot_bytes <= XFS_IFORK_DSIZE(ip))
+		*flags |= XFS_ILOG_DBROOT;
+	else {
+		cur = xfs_bmbt_init_cursor(mp, tp, ip, XFS_DATA_FORK);
+		cur->bc_private.b.flist = flist;
+		cur->bc_private.b.firstblock = *firstblock;
+		if ((error = xfs_bmbt_lookup_ge(cur, 0, 0, 0, &stat)))
+			goto error0;
+		/* must be at least one entry */
+		XFS_WANT_CORRUPTED_GOTO(mp, stat == 1, error0);
+		if ((error = xfs_btree_new_iroot(cur, flags, &stat)))
+			goto error0;
+		if (stat == 0) {
+			xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+			return -ENOSPC;
+		}
+		*firstblock = cur->bc_private.b.firstblock;
+		cur->bc_private.b.allocated = 0;
+		xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
+	}
+	return 0;
+error0:
+	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
+	return error;
+}
+
+/*
+ * Called from xfs_bmap_add_attrfork to handle extents format files.
+ */
+STATIC int					/* error */
+xfs_bmap_add_attrfork_extents(
+	xfs_trans_t		*tp,		/* transaction pointer */
+	xfs_inode_t		*ip,		/* incore inode pointer */
+	xfs_fsblock_t		*firstblock,	/* first block allocated */
+	xfs_bmap_free_t		*flist,		/* blocks to free at commit */
+	int			*flags)		/* inode logging flags */
+{
+	xfs_btree_cur_t		*cur;		/* bmap btree cursor */
+	int			error;		/* error return value */
+
+	if (ip->i_d.di_nextents * sizeof(xfs_bmbt_rec_t) <= XFS_IFORK_DSIZE(ip))
+		return 0;
+	cur = NULL;
+	error = xfs_bmap_extents_to_btree(tp, ip, firstblock, flist, &cur, 0,
+		flags, XFS_DATA_FORK);
+	if (cur) {
+		cur->bc_private.b.allocated = 0;
+		xfs_btree_del_cursor(cur,
+			error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+	}
+	return error;
+}
+
+/*
+ * Called from xfs_bmap_add_attrfork to handle local format files. Each
+ * different data fork content type needs a different callout to do the
+ * conversion. Some are basic and only require special block initialisation
+ * callouts for the data formating, others (directories) are so specialised they
+ * handle everything themselves.
+ *
+ * XXX (dgc): investigate whether directory conversion can use the generic
+ * formatting callout. It should be possible - it's just a very complex
+ * formatter.
+ */
+STATIC int					/* error */
+xfs_bmap_add_attrfork_local(
+	xfs_trans_t		*tp,		/* transaction pointer */
+	xfs_inode_t		*ip,		/* incore inode pointer */
+	xfs_fsblock_t		*firstblock,	/* first block allocated */
+	xfs_bmap_free_t		*flist,		/* blocks to free at commit */
+	int			*flags)		/* inode logging flags */
+{
+	xfs_da_args_t		dargs;		/* args for dir/attr code */
+
+	if (ip->i_df.if_bytes <= XFS_IFORK_DSIZE(ip))
+		return 0;
+
+	if (S_ISDIR(ip->i_d.di_mode)) {
+		memset(&dargs, 0, sizeof(dargs));
+		dargs.geo = ip->i_mount->m_dir_geo;
+		dargs.dp = ip;
+		dargs.firstblock = firstblock;
+		dargs.flist = flist;
+		dargs.total = dargs.geo->fsbcount;
+		dargs.whichfork = XFS_DATA_FORK;
+		dargs.trans = tp;
+		return xfs_dir2_sf_to_block(&dargs);
+	}
+
+	if (S_ISLNK(ip->i_d.di_mode))
+		return xfs_bmap_local_to_extents(tp, ip, firstblock, 1,
+						 flags, XFS_DATA_FORK,
+						 xfs_symlink_local_to_remote);
+
+	/* should only be called for types that support local format data */
+	ASSERT(0);
+	return -EFSCORRUPTED;
+}
+
+/*
+ * Convert inode from non-attributed to attributed.
+ * Must not be in a transaction, ip must not be locked.
+ */
+int						/* error code */
+xfs_bmap_add_attrfork(
+	xfs_inode_t		*ip,		/* incore inode pointer */
+	int			size,		/* space new attribute needs */
+	int			rsvd)		/* xact may use reserved blks */
+{
+	xfs_fsblock_t		firstblock;	/* 1st block/ag allocated */
+	xfs_bmap_free_t		flist;		/* freed extent records */
+	xfs_mount_t		*mp;		/* mount structure */
+	xfs_trans_t		*tp;		/* transaction pointer */
+	int			blks;		/* space reservation */
+	int			version = 1;	/* superblock attr version */
+	int			committed;	/* xaction was committed */
+	int			logflags;	/* logging flags */
+	int			error;		/* error return value */
+	int			cancel_flags = 0;
+
+	ASSERT(XFS_IFORK_Q(ip) == 0);
+
+	mp = ip->i_mount;
+	ASSERT(!XFS_NOT_DQATTACHED(mp, ip));
+	tp = xfs_trans_alloc(mp, XFS_TRANS_ADDAFORK);
+	blks = XFS_ADDAFORK_SPACE_RES(mp);
+	if (rsvd)
+		tp->t_flags |= XFS_TRANS_RESERVE;
+	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_addafork, blks, 0);
+	if (error) {
+		xfs_trans_cancel(tp, 0);
+		return error;
+	}
+	cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
+	xfs_ilock(ip, XFS_ILOCK_EXCL);
+	error = xfs_trans_reserve_quota_nblks(tp, ip, blks, 0, rsvd ?
+			XFS_QMOPT_RES_REGBLKS | XFS_QMOPT_FORCE_RES :
+			XFS_QMOPT_RES_REGBLKS);
+	if (error)
+		goto trans_cancel;
+	cancel_flags |= XFS_TRANS_ABORT;
+	if (XFS_IFORK_Q(ip))
+		goto trans_cancel;
+	if (ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS) {
+		/*
+		 * For inodes coming from pre-6.2 filesystems.
+		 */
+		ASSERT(ip->i_d.di_aformat == 0);
+		ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
+	}
+	ASSERT(ip->i_d.di_anextents == 0);
+
+	xfs_trans_ijoin(tp, ip, 0);
+	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+	switch (ip->i_d.di_format) {
+	case XFS_DINODE_FMT_DEV:
+		ip->i_d.di_forkoff = roundup(sizeof(xfs_dev_t), 8) >> 3;
+		break;
+	case XFS_DINODE_FMT_UUID:
+		ip->i_d.di_forkoff = roundup(sizeof(uuid_t), 8) >> 3;
+		break;
+	case XFS_DINODE_FMT_LOCAL:
+	case XFS_DINODE_FMT_EXTENTS:
+	case XFS_DINODE_FMT_BTREE:
+		ip->i_d.di_forkoff = xfs_attr_shortform_bytesfit(ip, size);
+		if (!ip->i_d.di_forkoff)
+			ip->i_d.di_forkoff = xfs_default_attroffset(ip) >> 3;
+		else if (mp->m_flags & XFS_MOUNT_ATTR2)
+			version = 2;
+		break;
+	default:
+		ASSERT(0);
+		error = -EINVAL;
+		goto trans_cancel;
+	}
+
+	ASSERT(ip->i_afp == NULL);
+	ip->i_afp = kmem_zone_zalloc(xfs_ifork_zone, KM_SLEEP);
+	ip->i_afp->if_flags = XFS_IFEXTENTS;
+	logflags = 0;
+	xfs_bmap_init(&flist, &firstblock);
+	switch (ip->i_d.di_format) {
+	case XFS_DINODE_FMT_LOCAL:
+		error = xfs_bmap_add_attrfork_local(tp, ip, &firstblock, &flist,
+			&logflags);
+		break;
+	case XFS_DINODE_FMT_EXTENTS:
+		error = xfs_bmap_add_attrfork_extents(tp, ip, &firstblock,
+			&flist, &logflags);
+		break;
+	case XFS_DINODE_FMT_BTREE:
+		error = xfs_bmap_add_attrfork_btree(tp, ip, &firstblock, &flist,
+			&logflags);
+		break;
+	default:
+		error = 0;
+		break;
+	}
+	if (logflags)
+		xfs_trans_log_inode(tp, ip, logflags);
+	if (error)
+		goto bmap_cancel;
+	if (!xfs_sb_version_hasattr(&mp->m_sb) ||
+	   (!xfs_sb_version_hasattr2(&mp->m_sb) && version == 2)) {
+		bool log_sb = false;
+
+		spin_lock(&mp->m_sb_lock);
+		if (!xfs_sb_version_hasattr(&mp->m_sb)) {
+			xfs_sb_version_addattr(&mp->m_sb);
+			log_sb = true;
+		}
+		if (!xfs_sb_version_hasattr2(&mp->m_sb) && version == 2) {
+			xfs_sb_version_addattr2(&mp->m_sb);
+			log_sb = true;
+		}
+		spin_unlock(&mp->m_sb_lock);
+		if (log_sb)
+			xfs_log_sb(tp);
+	}
+
+	error = xfs_bmap_finish(&tp, &flist, &committed);
+	if (error)
+		goto bmap_cancel;
+	error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	return error;
+
+bmap_cancel:
+	xfs_bmap_cancel(&flist);
+trans_cancel:
+	xfs_trans_cancel(tp, cancel_flags);
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	return error;
+}
+
+/*
+ * Internal and external extent tree search functions.
+ */
+
+/*
+ * Read in the extents to if_extents.
+ * All inode fields are set up by caller, we just traverse the btree
+ * and copy the records in. If the file system cannot contain unwritten
+ * extents, the records are checked for no "state" flags.
+ */
+int					/* error */
+xfs_bmap_read_extents(
+	xfs_trans_t		*tp,	/* transaction pointer */
+	xfs_inode_t		*ip,	/* incore inode */
+	int			whichfork) /* data or attr fork */
+{
+	struct xfs_btree_block	*block;	/* current btree block */
+	xfs_fsblock_t		bno;	/* block # of "block" */
+	xfs_buf_t		*bp;	/* buffer for "block" */
+	int			error;	/* error return value */
+	xfs_exntfmt_t		exntf;	/* XFS_EXTFMT_NOSTATE, if checking */
+	xfs_extnum_t		i, j;	/* index into the extents list */
+	xfs_ifork_t		*ifp;	/* fork structure */
+	int			level;	/* btree level, for checking */
+	xfs_mount_t		*mp;	/* file system mount structure */
+	__be64			*pp;	/* pointer to block address */
+	/* REFERENCED */
+	xfs_extnum_t		room;	/* number of entries there's room for */
+
+	bno = NULLFSBLOCK;
+	mp = ip->i_mount;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	exntf = (whichfork != XFS_DATA_FORK) ? XFS_EXTFMT_NOSTATE :
+					XFS_EXTFMT_INODE(ip);
+	block = ifp->if_broot;
+	/*
+	 * Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
+	 */
+	level = be16_to_cpu(block->bb_level);
+	ASSERT(level > 0);
+	pp = XFS_BMAP_BROOT_PTR_ADDR(mp, block, 1, ifp->if_broot_bytes);
+	bno = be64_to_cpu(*pp);
+	ASSERT(bno != NULLFSBLOCK);
+	ASSERT(XFS_FSB_TO_AGNO(mp, bno) < mp->m_sb.sb_agcount);
+	ASSERT(XFS_FSB_TO_AGBNO(mp, bno) < mp->m_sb.sb_agblocks);
+	/*
+	 * Go down the tree until leaf level is reached, following the first
+	 * pointer (leftmost) at each level.
+	 */
+	while (level-- > 0) {
+		error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
+				XFS_BMAP_BTREE_REF, &xfs_bmbt_buf_ops);
+		if (error)
+			return error;
+		block = XFS_BUF_TO_BLOCK(bp);
+		if (level == 0)
+			break;
+		pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
+		bno = be64_to_cpu(*pp);
+		XFS_WANT_CORRUPTED_GOTO(mp,
+			XFS_FSB_SANITY_CHECK(mp, bno), error0);
+		xfs_trans_brelse(tp, bp);
+	}
+	/*
+	 * Here with bp and block set to the leftmost leaf node in the tree.
+	 */
+	room = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	i = 0;
+	/*
+	 * Loop over all leaf nodes.  Copy information to the extent records.
+	 */
+	for (;;) {
+		xfs_bmbt_rec_t	*frp;
+		xfs_fsblock_t	nextbno;
+		xfs_extnum_t	num_recs;
+		xfs_extnum_t	start;
+
+		num_recs = xfs_btree_get_numrecs(block);
+		if (unlikely(i + num_recs > room)) {
+			ASSERT(i + num_recs <= room);
+			xfs_warn(ip->i_mount,
+				"corrupt dinode %Lu, (btree extents).",
+				(unsigned long long) ip->i_ino);
+			XFS_CORRUPTION_ERROR("xfs_bmap_read_extents(1)",
+				XFS_ERRLEVEL_LOW, ip->i_mount, block);
+			goto error0;
+		}
+		/*
+		 * Read-ahead the next leaf block, if any.
+		 */
+		nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
+		if (nextbno != NULLFSBLOCK)
+			xfs_btree_reada_bufl(mp, nextbno, 1,
+					     &xfs_bmbt_buf_ops);
+		/*
+		 * Copy records into the extent records.
+		 */
+		frp = XFS_BMBT_REC_ADDR(mp, block, 1);
+		start = i;
+		for (j = 0; j < num_recs; j++, i++, frp++) {
+			xfs_bmbt_rec_host_t *trp = xfs_iext_get_ext(ifp, i);
+			trp->l0 = be64_to_cpu(frp->l0);
+			trp->l1 = be64_to_cpu(frp->l1);
+		}
+		if (exntf == XFS_EXTFMT_NOSTATE) {
+			/*
+			 * Check all attribute bmap btree records and
+			 * any "older" data bmap btree records for a
+			 * set bit in the "extent flag" position.
+			 */
+			if (unlikely(xfs_check_nostate_extents(ifp,
+					start, num_recs))) {
+				XFS_ERROR_REPORT("xfs_bmap_read_extents(2)",
+						 XFS_ERRLEVEL_LOW,
+						 ip->i_mount);
+				goto error0;
+			}
+		}
+		xfs_trans_brelse(tp, bp);
+		bno = nextbno;
+		/*
+		 * If we've reached the end, stop.
+		 */
+		if (bno == NULLFSBLOCK)
+			break;
+		error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
+				XFS_BMAP_BTREE_REF, &xfs_bmbt_buf_ops);
+		if (error)
+			return error;
+		block = XFS_BUF_TO_BLOCK(bp);
+	}
+	ASSERT(i == (ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t)));
+	ASSERT(i == XFS_IFORK_NEXTENTS(ip, whichfork));
+	XFS_BMAP_TRACE_EXLIST(ip, i, whichfork);
+	return 0;
+error0:
+	xfs_trans_brelse(tp, bp);
+	return -EFSCORRUPTED;
+}
+
+
+/*
+ * Search the extent records for the entry containing block bno.
+ * If bno lies in a hole, point to the next entry.  If bno lies
+ * past eof, *eofp will be set, and *prevp will contain the last
+ * entry (null if none).  Else, *lastxp will be set to the index
+ * of the found entry; *gotp will contain the entry.
+ */
+STATIC xfs_bmbt_rec_host_t *		/* pointer to found extent entry */
+xfs_bmap_search_multi_extents(
+	xfs_ifork_t	*ifp,		/* inode fork pointer */
+	xfs_fileoff_t	bno,		/* block number searched for */
+	int		*eofp,		/* out: end of file found */
+	xfs_extnum_t	*lastxp,	/* out: last extent index */
+	xfs_bmbt_irec_t	*gotp,		/* out: extent entry found */
+	xfs_bmbt_irec_t	*prevp)		/* out: previous extent entry found */
+{
+	xfs_bmbt_rec_host_t *ep;		/* extent record pointer */
+	xfs_extnum_t	lastx;		/* last extent index */
+
+	/*
+	 * Initialize the extent entry structure to catch access to
+	 * uninitialized br_startblock field.
+	 */
+	gotp->br_startoff = 0xffa5a5a5a5a5a5a5LL;
+	gotp->br_blockcount = 0xa55a5a5a5a5a5a5aLL;
+	gotp->br_state = XFS_EXT_INVALID;
+	gotp->br_startblock = 0xffffa5a5a5a5a5a5LL;
+	prevp->br_startoff = NULLFILEOFF;
+
+	ep = xfs_iext_bno_to_ext(ifp, bno, &lastx);
+	if (lastx > 0) {
+		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, lastx - 1), prevp);
+	}
+	if (lastx < (ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t))) {
+		xfs_bmbt_get_all(ep, gotp);
+		*eofp = 0;
+	} else {
+		if (lastx > 0) {
+			*gotp = *prevp;
+		}
+		*eofp = 1;
+		ep = NULL;
+	}
+	*lastxp = lastx;
+	return ep;
+}
+
+/*
+ * Search the extents list for the inode, for the extent containing bno.
+ * If bno lies in a hole, point to the next entry.  If bno lies past eof,
+ * *eofp will be set, and *prevp will contain the last entry (null if none).
+ * Else, *lastxp will be set to the index of the found
+ * entry; *gotp will contain the entry.
+ */
+STATIC xfs_bmbt_rec_host_t *                 /* pointer to found extent entry */
+xfs_bmap_search_extents(
+	xfs_inode_t     *ip,            /* incore inode pointer */
+	xfs_fileoff_t   bno,            /* block number searched for */
+	int             fork,      	/* data or attr fork */
+	int             *eofp,          /* out: end of file found */
+	xfs_extnum_t    *lastxp,        /* out: last extent index */
+	xfs_bmbt_irec_t *gotp,          /* out: extent entry found */
+	xfs_bmbt_irec_t *prevp)         /* out: previous extent entry found */
+{
+	xfs_ifork_t	*ifp;		/* inode fork pointer */
+	xfs_bmbt_rec_host_t  *ep;            /* extent record pointer */
+
+	XFS_STATS_INC(xs_look_exlist);
+	ifp = XFS_IFORK_PTR(ip, fork);
+
+	ep = xfs_bmap_search_multi_extents(ifp, bno, eofp, lastxp, gotp, prevp);
+
+	if (unlikely(!(gotp->br_startblock) && (*lastxp != NULLEXTNUM) &&
+		     !(XFS_IS_REALTIME_INODE(ip) && fork == XFS_DATA_FORK))) {
+		xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO,
+				"Access to block zero in inode %llu "
+				"start_block: %llx start_off: %llx "
+				"blkcnt: %llx extent-state: %x lastx: %x",
+			(unsigned long long)ip->i_ino,
+			(unsigned long long)gotp->br_startblock,
+			(unsigned long long)gotp->br_startoff,
+			(unsigned long long)gotp->br_blockcount,
+			gotp->br_state, *lastxp);
+		*lastxp = NULLEXTNUM;
+		*eofp = 1;
+		return NULL;
+	}
+	return ep;
+}
+
+/*
+ * Returns the file-relative block number of the first unused block(s)
+ * in the file with at least "len" logically contiguous blocks free.
+ * This is the lowest-address hole if the file has holes, else the first block
+ * past the end of file.
+ * Return 0 if the file is currently local (in-inode).
+ */
+int						/* error */
+xfs_bmap_first_unused(
+	xfs_trans_t	*tp,			/* transaction pointer */
+	xfs_inode_t	*ip,			/* incore inode */
+	xfs_extlen_t	len,			/* size of hole to find */
+	xfs_fileoff_t	*first_unused,		/* unused block */
+	int		whichfork)		/* data or attr fork */
+{
+	int		error;			/* error return value */
+	int		idx;			/* extent record index */
+	xfs_ifork_t	*ifp;			/* inode fork pointer */
+	xfs_fileoff_t	lastaddr;		/* last block number seen */
+	xfs_fileoff_t	lowest;			/* lowest useful block */
+	xfs_fileoff_t	max;			/* starting useful block */
+	xfs_fileoff_t	off;			/* offset for this block */
+	xfs_extnum_t	nextents;		/* number of extent entries */
+
+	ASSERT(XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_BTREE ||
+	       XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_EXTENTS ||
+	       XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL);
+	if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
+		*first_unused = 0;
+		return 0;
+	}
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	if (!(ifp->if_flags & XFS_IFEXTENTS) &&
+	    (error = xfs_iread_extents(tp, ip, whichfork)))
+		return error;
+	lowest = *first_unused;
+	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	for (idx = 0, lastaddr = 0, max = lowest; idx < nextents; idx++) {
+		xfs_bmbt_rec_host_t *ep = xfs_iext_get_ext(ifp, idx);
+		off = xfs_bmbt_get_startoff(ep);
+		/*
+		 * See if the hole before this extent will work.
+		 */
+		if (off >= lowest + len && off - max >= len) {
+			*first_unused = max;
+			return 0;
+		}
+		lastaddr = off + xfs_bmbt_get_blockcount(ep);
+		max = XFS_FILEOFF_MAX(lastaddr, lowest);
+	}
+	*first_unused = max;
+	return 0;
+}
+
+/*
+ * Returns the file-relative block number of the last block - 1 before
+ * last_block (input value) in the file.
+ * This is not based on i_size, it is based on the extent records.
+ * Returns 0 for local files, as they do not have extent records.
+ */
+int						/* error */
+xfs_bmap_last_before(
+	xfs_trans_t	*tp,			/* transaction pointer */
+	xfs_inode_t	*ip,			/* incore inode */
+	xfs_fileoff_t	*last_block,		/* last block */
+	int		whichfork)		/* data or attr fork */
+{
+	xfs_fileoff_t	bno;			/* input file offset */
+	int		eof;			/* hit end of file */
+	xfs_bmbt_rec_host_t *ep;		/* pointer to last extent */
+	int		error;			/* error return value */
+	xfs_bmbt_irec_t	got;			/* current extent value */
+	xfs_ifork_t	*ifp;			/* inode fork pointer */
+	xfs_extnum_t	lastx;			/* last extent used */
+	xfs_bmbt_irec_t	prev;			/* previous extent value */
+
+	if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE &&
+	    XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+	    XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL)
+	       return -EIO;
+	if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
+		*last_block = 0;
+		return 0;
+	}
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	if (!(ifp->if_flags & XFS_IFEXTENTS) &&
+	    (error = xfs_iread_extents(tp, ip, whichfork)))
+		return error;
+	bno = *last_block - 1;
+	ep = xfs_bmap_search_extents(ip, bno, whichfork, &eof, &lastx, &got,
+		&prev);
+	if (eof || xfs_bmbt_get_startoff(ep) > bno) {
+		if (prev.br_startoff == NULLFILEOFF)
+			*last_block = 0;
+		else
+			*last_block = prev.br_startoff + prev.br_blockcount;
+	}
+	/*
+	 * Otherwise *last_block is already the right answer.
+	 */
+	return 0;
+}
+
+int
+xfs_bmap_last_extent(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	int			whichfork,
+	struct xfs_bmbt_irec	*rec,
+	int			*is_empty)
+{
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+	int			error;
+	int			nextents;
+
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		error = xfs_iread_extents(tp, ip, whichfork);
+		if (error)
+			return error;
+	}
+
+	nextents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
+	if (nextents == 0) {
+		*is_empty = 1;
+		return 0;
+	}
+
+	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, nextents - 1), rec);
+	*is_empty = 0;
+	return 0;
+}
+
+/*
+ * Check the last inode extent to determine whether this allocation will result
+ * in blocks being allocated at the end of the file. When we allocate new data
+ * blocks at the end of the file which do not start at the previous data block,
+ * we will try to align the new blocks at stripe unit boundaries.
+ *
+ * Returns 1 in bma->aeof if the file (fork) is empty as any new write will be
+ * at, or past the EOF.
+ */
+STATIC int
+xfs_bmap_isaeof(
+	struct xfs_bmalloca	*bma,
+	int			whichfork)
+{
+	struct xfs_bmbt_irec	rec;
+	int			is_empty;
+	int			error;
+
+	bma->aeof = 0;
+	error = xfs_bmap_last_extent(NULL, bma->ip, whichfork, &rec,
+				     &is_empty);
+	if (error)
+		return error;
+
+	if (is_empty) {
+		bma->aeof = 1;
+		return 0;
+	}
+
+	/*
+	 * Check if we are allocation or past the last extent, or at least into
+	 * the last delayed allocated extent.
+	 */
+	bma->aeof = bma->offset >= rec.br_startoff + rec.br_blockcount ||
+		(bma->offset >= rec.br_startoff &&
+		 isnullstartblock(rec.br_startblock));
+	return 0;
+}
+
+/*
+ * Returns the file-relative block number of the first block past eof in
+ * the file.  This is not based on i_size, it is based on the extent records.
+ * Returns 0 for local files, as they do not have extent records.
+ */
+int
+xfs_bmap_last_offset(
+	struct xfs_inode	*ip,
+	xfs_fileoff_t		*last_block,
+	int			whichfork)
+{
+	struct xfs_bmbt_irec	rec;
+	int			is_empty;
+	int			error;
+
+	*last_block = 0;
+
+	if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL)
+		return 0;
+
+	if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE &&
+	    XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS)
+	       return -EIO;
+
+	error = xfs_bmap_last_extent(NULL, ip, whichfork, &rec, &is_empty);
+	if (error || is_empty)
+		return error;
+
+	*last_block = rec.br_startoff + rec.br_blockcount;
+	return 0;
+}
+
+/*
+ * Returns whether the selected fork of the inode has exactly one
+ * block or not.  For the data fork we check this matches di_size,
+ * implying the file's range is 0..bsize-1.
+ */
+int					/* 1=>1 block, 0=>otherwise */
+xfs_bmap_one_block(
+	xfs_inode_t	*ip,		/* incore inode */
+	int		whichfork)	/* data or attr fork */
+{
+	xfs_bmbt_rec_host_t *ep;	/* ptr to fork's extent */
+	xfs_ifork_t	*ifp;		/* inode fork pointer */
+	int		rval;		/* return value */
+	xfs_bmbt_irec_t	s;		/* internal version of extent */
+
+#ifndef DEBUG
+	if (whichfork == XFS_DATA_FORK)
+		return XFS_ISIZE(ip) == ip->i_mount->m_sb.sb_blocksize;
+#endif	/* !DEBUG */
+	if (XFS_IFORK_NEXTENTS(ip, whichfork) != 1)
+		return 0;
+	if (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS)
+		return 0;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	ASSERT(ifp->if_flags & XFS_IFEXTENTS);
+	ep = xfs_iext_get_ext(ifp, 0);
+	xfs_bmbt_get_all(ep, &s);
+	rval = s.br_startoff == 0 && s.br_blockcount == 1;
+	if (rval && whichfork == XFS_DATA_FORK)
+		ASSERT(XFS_ISIZE(ip) == ip->i_mount->m_sb.sb_blocksize);
+	return rval;
+}
+
+/*
+ * Extent tree manipulation functions used during allocation.
+ */
+
+/*
+ * Convert a delayed allocation to a real allocation.
+ */
+STATIC int				/* error */
+xfs_bmap_add_extent_delay_real(
+	struct xfs_bmalloca	*bma)
+{
+	struct xfs_bmbt_irec	*new = &bma->got;
+	int			diff;	/* temp value */
+	xfs_bmbt_rec_host_t	*ep;	/* extent entry for idx */
+	int			error;	/* error return value */
+	int			i;	/* temp state */
+	xfs_ifork_t		*ifp;	/* inode fork pointer */
+	xfs_fileoff_t		new_endoff;	/* end offset of new entry */
+	xfs_bmbt_irec_t		r[3];	/* neighbor extent entries */
+					/* left is 0, right is 1, prev is 2 */
+	int			rval=0;	/* return value (logging flags) */
+	int			state = 0;/* state bits, accessed thru macros */
+	xfs_filblks_t		da_new; /* new count del alloc blocks used */
+	xfs_filblks_t		da_old; /* old count del alloc blocks used */
+	xfs_filblks_t		temp=0;	/* value for da_new calculations */
+	xfs_filblks_t		temp2=0;/* value for da_new calculations */
+	int			tmp_rval;	/* partial logging flags */
+	struct xfs_mount	*mp;
+
+	mp  = bma->tp ? bma->tp->t_mountp : NULL;
+	ifp = XFS_IFORK_PTR(bma->ip, XFS_DATA_FORK);
+
+	ASSERT(bma->idx >= 0);
+	ASSERT(bma->idx <= ifp->if_bytes / sizeof(struct xfs_bmbt_rec));
+	ASSERT(!isnullstartblock(new->br_startblock));
+	ASSERT(!bma->cur ||
+	       (bma->cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL));
+
+	XFS_STATS_INC(xs_add_exlist);
+
+#define	LEFT		r[0]
+#define	RIGHT		r[1]
+#define	PREV		r[2]
+
+	/*
+	 * Set up a bunch of variables to make the tests simpler.
+	 */
+	ep = xfs_iext_get_ext(ifp, bma->idx);
+	xfs_bmbt_get_all(ep, &PREV);
+	new_endoff = new->br_startoff + new->br_blockcount;
+	ASSERT(PREV.br_startoff <= new->br_startoff);
+	ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
+
+	da_old = startblockval(PREV.br_startblock);
+	da_new = 0;
+
+	/*
+	 * Set flags determining what part of the previous delayed allocation
+	 * extent is being replaced by a real allocation.
+	 */
+	if (PREV.br_startoff == new->br_startoff)
+		state |= BMAP_LEFT_FILLING;
+	if (PREV.br_startoff + PREV.br_blockcount == new_endoff)
+		state |= BMAP_RIGHT_FILLING;
+
+	/*
+	 * Check and set flags if this segment has a left neighbor.
+	 * Don't set contiguous if the combined extent would be too large.
+	 */
+	if (bma->idx > 0) {
+		state |= BMAP_LEFT_VALID;
+		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx - 1), &LEFT);
+
+		if (isnullstartblock(LEFT.br_startblock))
+			state |= BMAP_LEFT_DELAY;
+	}
+
+	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
+	    LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
+	    LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
+	    LEFT.br_state == new->br_state &&
+	    LEFT.br_blockcount + new->br_blockcount <= MAXEXTLEN)
+		state |= BMAP_LEFT_CONTIG;
+
+	/*
+	 * Check and set flags if this segment has a right neighbor.
+	 * Don't set contiguous if the combined extent would be too large.
+	 * Also check for all-three-contiguous being too large.
+	 */
+	if (bma->idx < bma->ip->i_df.if_bytes / (uint)sizeof(xfs_bmbt_rec_t) - 1) {
+		state |= BMAP_RIGHT_VALID;
+		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx + 1), &RIGHT);
+
+		if (isnullstartblock(RIGHT.br_startblock))
+			state |= BMAP_RIGHT_DELAY;
+	}
+
+	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
+	    new_endoff == RIGHT.br_startoff &&
+	    new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
+	    new->br_state == RIGHT.br_state &&
+	    new->br_blockcount + RIGHT.br_blockcount <= MAXEXTLEN &&
+	    ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
+		       BMAP_RIGHT_FILLING)) !=
+		      (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
+		       BMAP_RIGHT_FILLING) ||
+	     LEFT.br_blockcount + new->br_blockcount + RIGHT.br_blockcount
+			<= MAXEXTLEN))
+		state |= BMAP_RIGHT_CONTIG;
+
+	error = 0;
+	/*
+	 * Switch out based on the FILLING and CONTIG state bits.
+	 */
+	switch (state & (BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
+			 BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG)) {
+	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
+	     BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
+		/*
+		 * Filling in all of a previously delayed allocation extent.
+		 * The left and right neighbors are both contiguous with new.
+		 */
+		bma->idx--;
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, bma->idx),
+			LEFT.br_blockcount + PREV.br_blockcount +
+			RIGHT.br_blockcount);
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		xfs_iext_remove(bma->ip, bma->idx + 1, 2, state);
+		bma->ip->i_d.di_nextents--;
+		if (bma->cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			error = xfs_bmbt_lookup_eq(bma->cur, RIGHT.br_startoff,
+					RIGHT.br_startblock,
+					RIGHT.br_blockcount, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_btree_delete(bma->cur, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_btree_decrement(bma->cur, 0, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_bmbt_update(bma->cur, LEFT.br_startoff,
+					LEFT.br_startblock,
+					LEFT.br_blockcount +
+					PREV.br_blockcount +
+					RIGHT.br_blockcount, LEFT.br_state);
+			if (error)
+				goto done;
+		}
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
+		/*
+		 * Filling in all of a previously delayed allocation extent.
+		 * The left neighbor is contiguous, the right is not.
+		 */
+		bma->idx--;
+
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, bma->idx),
+			LEFT.br_blockcount + PREV.br_blockcount);
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		xfs_iext_remove(bma->ip, bma->idx + 1, 1, state);
+		if (bma->cur == NULL)
+			rval = XFS_ILOG_DEXT;
+		else {
+			rval = 0;
+			error = xfs_bmbt_lookup_eq(bma->cur, LEFT.br_startoff,
+					LEFT.br_startblock, LEFT.br_blockcount,
+					&i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_bmbt_update(bma->cur, LEFT.br_startoff,
+					LEFT.br_startblock,
+					LEFT.br_blockcount +
+					PREV.br_blockcount, LEFT.br_state);
+			if (error)
+				goto done;
+		}
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
+		/*
+		 * Filling in all of a previously delayed allocation extent.
+		 * The right neighbor is contiguous, the left is not.
+		 */
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_startblock(ep, new->br_startblock);
+		xfs_bmbt_set_blockcount(ep,
+			PREV.br_blockcount + RIGHT.br_blockcount);
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		xfs_iext_remove(bma->ip, bma->idx + 1, 1, state);
+		if (bma->cur == NULL)
+			rval = XFS_ILOG_DEXT;
+		else {
+			rval = 0;
+			error = xfs_bmbt_lookup_eq(bma->cur, RIGHT.br_startoff,
+					RIGHT.br_startblock,
+					RIGHT.br_blockcount, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_bmbt_update(bma->cur, PREV.br_startoff,
+					new->br_startblock,
+					PREV.br_blockcount +
+					RIGHT.br_blockcount, PREV.br_state);
+			if (error)
+				goto done;
+		}
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
+		/*
+		 * Filling in all of a previously delayed allocation extent.
+		 * Neither the left nor right neighbors are contiguous with
+		 * the new one.
+		 */
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_startblock(ep, new->br_startblock);
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		bma->ip->i_d.di_nextents++;
+		if (bma->cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			error = xfs_bmbt_lookup_eq(bma->cur, new->br_startoff,
+					new->br_startblock, new->br_blockcount,
+					&i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
+			bma->cur->bc_rec.b.br_state = XFS_EXT_NORM;
+			error = xfs_btree_insert(bma->cur, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		}
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG:
+		/*
+		 * Filling in the first part of a previous delayed allocation.
+		 * The left neighbor is contiguous.
+		 */
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx - 1, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, bma->idx - 1),
+			LEFT.br_blockcount + new->br_blockcount);
+		xfs_bmbt_set_startoff(ep,
+			PREV.br_startoff + new->br_blockcount);
+		trace_xfs_bmap_post_update(bma->ip, bma->idx - 1, state, _THIS_IP_);
+
+		temp = PREV.br_blockcount - new->br_blockcount;
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep, temp);
+		if (bma->cur == NULL)
+			rval = XFS_ILOG_DEXT;
+		else {
+			rval = 0;
+			error = xfs_bmbt_lookup_eq(bma->cur, LEFT.br_startoff,
+					LEFT.br_startblock, LEFT.br_blockcount,
+					&i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_bmbt_update(bma->cur, LEFT.br_startoff,
+					LEFT.br_startblock,
+					LEFT.br_blockcount +
+					new->br_blockcount,
+					LEFT.br_state);
+			if (error)
+				goto done;
+		}
+		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
+			startblockval(PREV.br_startblock));
+		xfs_bmbt_set_startblock(ep, nullstartblock(da_new));
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		bma->idx--;
+		break;
+
+	case BMAP_LEFT_FILLING:
+		/*
+		 * Filling in the first part of a previous delayed allocation.
+		 * The left neighbor is not contiguous.
+		 */
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_startoff(ep, new_endoff);
+		temp = PREV.br_blockcount - new->br_blockcount;
+		xfs_bmbt_set_blockcount(ep, temp);
+		xfs_iext_insert(bma->ip, bma->idx, 1, new, state);
+		bma->ip->i_d.di_nextents++;
+		if (bma->cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			error = xfs_bmbt_lookup_eq(bma->cur, new->br_startoff,
+					new->br_startblock, new->br_blockcount,
+					&i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
+			bma->cur->bc_rec.b.br_state = XFS_EXT_NORM;
+			error = xfs_btree_insert(bma->cur, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		}
+
+		if (xfs_bmap_needs_btree(bma->ip, XFS_DATA_FORK)) {
+			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
+					bma->firstblock, bma->flist,
+					&bma->cur, 1, &tmp_rval, XFS_DATA_FORK);
+			rval |= tmp_rval;
+			if (error)
+				goto done;
+		}
+		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
+			startblockval(PREV.br_startblock) -
+			(bma->cur ? bma->cur->bc_private.b.allocated : 0));
+		ep = xfs_iext_get_ext(ifp, bma->idx + 1);
+		xfs_bmbt_set_startblock(ep, nullstartblock(da_new));
+		trace_xfs_bmap_post_update(bma->ip, bma->idx + 1, state, _THIS_IP_);
+		break;
+
+	case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
+		/*
+		 * Filling in the last part of a previous delayed allocation.
+		 * The right neighbor is contiguous with the new allocation.
+		 */
+		temp = PREV.br_blockcount - new->br_blockcount;
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx + 1, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep, temp);
+		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, bma->idx + 1),
+			new->br_startoff, new->br_startblock,
+			new->br_blockcount + RIGHT.br_blockcount,
+			RIGHT.br_state);
+		trace_xfs_bmap_post_update(bma->ip, bma->idx + 1, state, _THIS_IP_);
+		if (bma->cur == NULL)
+			rval = XFS_ILOG_DEXT;
+		else {
+			rval = 0;
+			error = xfs_bmbt_lookup_eq(bma->cur, RIGHT.br_startoff,
+					RIGHT.br_startblock,
+					RIGHT.br_blockcount, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_bmbt_update(bma->cur, new->br_startoff,
+					new->br_startblock,
+					new->br_blockcount +
+					RIGHT.br_blockcount,
+					RIGHT.br_state);
+			if (error)
+				goto done;
+		}
+
+		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
+			startblockval(PREV.br_startblock));
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_startblock(ep, nullstartblock(da_new));
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		bma->idx++;
+		break;
+
+	case BMAP_RIGHT_FILLING:
+		/*
+		 * Filling in the last part of a previous delayed allocation.
+		 * The right neighbor is not contiguous.
+		 */
+		temp = PREV.br_blockcount - new->br_blockcount;
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep, temp);
+		xfs_iext_insert(bma->ip, bma->idx + 1, 1, new, state);
+		bma->ip->i_d.di_nextents++;
+		if (bma->cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			error = xfs_bmbt_lookup_eq(bma->cur, new->br_startoff,
+					new->br_startblock, new->br_blockcount,
+					&i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
+			bma->cur->bc_rec.b.br_state = XFS_EXT_NORM;
+			error = xfs_btree_insert(bma->cur, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		}
+
+		if (xfs_bmap_needs_btree(bma->ip, XFS_DATA_FORK)) {
+			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
+				bma->firstblock, bma->flist, &bma->cur, 1,
+				&tmp_rval, XFS_DATA_FORK);
+			rval |= tmp_rval;
+			if (error)
+				goto done;
+		}
+		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
+			startblockval(PREV.br_startblock) -
+			(bma->cur ? bma->cur->bc_private.b.allocated : 0));
+		ep = xfs_iext_get_ext(ifp, bma->idx);
+		xfs_bmbt_set_startblock(ep, nullstartblock(da_new));
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		bma->idx++;
+		break;
+
+	case 0:
+		/*
+		 * Filling in the middle part of a previous delayed allocation.
+		 * Contiguity is impossible here.
+		 * This case is avoided almost all the time.
+		 *
+		 * We start with a delayed allocation:
+		 *
+		 * +ddddddddddddddddddddddddddddddddddddddddddddddddddddddd+
+		 *  PREV @ idx
+		 *
+	         * and we are allocating:
+		 *                     +rrrrrrrrrrrrrrrrr+
+		 *			      new
+		 *
+		 * and we set it up for insertion as:
+		 * +ddddddddddddddddddd+rrrrrrrrrrrrrrrrr+ddddddddddddddddd+
+		 *                            new
+		 *  PREV @ idx          LEFT              RIGHT
+		 *                      inserted at idx + 1
+		 */
+		temp = new->br_startoff - PREV.br_startoff;
+		temp2 = PREV.br_startoff + PREV.br_blockcount - new_endoff;
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, 0, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep, temp);	/* truncate PREV */
+		LEFT = *new;
+		RIGHT.br_state = PREV.br_state;
+		RIGHT.br_startblock = nullstartblock(
+				(int)xfs_bmap_worst_indlen(bma->ip, temp2));
+		RIGHT.br_startoff = new_endoff;
+		RIGHT.br_blockcount = temp2;
+		/* insert LEFT (r[0]) and RIGHT (r[1]) at the same time */
+		xfs_iext_insert(bma->ip, bma->idx + 1, 2, &LEFT, state);
+		bma->ip->i_d.di_nextents++;
+		if (bma->cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			error = xfs_bmbt_lookup_eq(bma->cur, new->br_startoff,
+					new->br_startblock, new->br_blockcount,
+					&i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
+			bma->cur->bc_rec.b.br_state = XFS_EXT_NORM;
+			error = xfs_btree_insert(bma->cur, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		}
+
+		if (xfs_bmap_needs_btree(bma->ip, XFS_DATA_FORK)) {
+			error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
+					bma->firstblock, bma->flist, &bma->cur,
+					1, &tmp_rval, XFS_DATA_FORK);
+			rval |= tmp_rval;
+			if (error)
+				goto done;
+		}
+		temp = xfs_bmap_worst_indlen(bma->ip, temp);
+		temp2 = xfs_bmap_worst_indlen(bma->ip, temp2);
+		diff = (int)(temp + temp2 - startblockval(PREV.br_startblock) -
+			(bma->cur ? bma->cur->bc_private.b.allocated : 0));
+		if (diff > 0) {
+			error = xfs_mod_fdblocks(bma->ip->i_mount,
+						 -((int64_t)diff), false);
+			ASSERT(!error);
+			if (error)
+				goto done;
+		}
+
+		ep = xfs_iext_get_ext(ifp, bma->idx);
+		xfs_bmbt_set_startblock(ep, nullstartblock((int)temp));
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx + 2, state, _THIS_IP_);
+		xfs_bmbt_set_startblock(xfs_iext_get_ext(ifp, bma->idx + 2),
+			nullstartblock((int)temp2));
+		trace_xfs_bmap_post_update(bma->ip, bma->idx + 2, state, _THIS_IP_);
+
+		bma->idx++;
+		da_new = temp + temp2;
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_CONTIG:
+	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
+	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+	case BMAP_LEFT_CONTIG:
+	case BMAP_RIGHT_CONTIG:
+		/*
+		 * These cases are all impossible.
+		 */
+		ASSERT(0);
+	}
+
+	/* convert to a btree if necessary */
+	if (xfs_bmap_needs_btree(bma->ip, XFS_DATA_FORK)) {
+		int	tmp_logflags;	/* partial log flag return val */
+
+		ASSERT(bma->cur == NULL);
+		error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
+				bma->firstblock, bma->flist, &bma->cur,
+				da_old > 0, &tmp_logflags, XFS_DATA_FORK);
+		bma->logflags |= tmp_logflags;
+		if (error)
+			goto done;
+	}
+
+	/* adjust for changes in reserved delayed indirect blocks */
+	if (da_old || da_new) {
+		temp = da_new;
+		if (bma->cur)
+			temp += bma->cur->bc_private.b.allocated;
+		ASSERT(temp <= da_old);
+		if (temp < da_old)
+			xfs_mod_fdblocks(bma->ip->i_mount,
+					(int64_t)(da_old - temp), false);
+	}
+
+	/* clear out the allocated field, done with it now in any case. */
+	if (bma->cur)
+		bma->cur->bc_private.b.allocated = 0;
+
+	xfs_bmap_check_leaf_extents(bma->cur, bma->ip, XFS_DATA_FORK);
+done:
+	bma->logflags |= rval;
+	return error;
+#undef	LEFT
+#undef	RIGHT
+#undef	PREV
+}
+
+/*
+ * Convert an unwritten allocation to a real allocation or vice versa.
+ */
+STATIC int				/* error */
+xfs_bmap_add_extent_unwritten_real(
+	struct xfs_trans	*tp,
+	xfs_inode_t		*ip,	/* incore inode pointer */
+	xfs_extnum_t		*idx,	/* extent number to update/insert */
+	xfs_btree_cur_t		**curp,	/* if *curp is null, not a btree */
+	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
+	xfs_fsblock_t		*first,	/* pointer to firstblock variable */
+	xfs_bmap_free_t		*flist,	/* list of extents to be freed */
+	int			*logflagsp) /* inode logging flags */
+{
+	xfs_btree_cur_t		*cur;	/* btree cursor */
+	xfs_bmbt_rec_host_t	*ep;	/* extent entry for idx */
+	int			error;	/* error return value */
+	int			i;	/* temp state */
+	xfs_ifork_t		*ifp;	/* inode fork pointer */
+	xfs_fileoff_t		new_endoff;	/* end offset of new entry */
+	xfs_exntst_t		newext;	/* new extent state */
+	xfs_exntst_t		oldext;	/* old extent state */
+	xfs_bmbt_irec_t		r[3];	/* neighbor extent entries */
+					/* left is 0, right is 1, prev is 2 */
+	int			rval=0;	/* return value (logging flags) */
+	int			state = 0;/* state bits, accessed thru macros */
+	struct xfs_mount	*mp = tp->t_mountp;
+
+	*logflagsp = 0;
+
+	cur = *curp;
+	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+
+	ASSERT(*idx >= 0);
+	ASSERT(*idx <= ifp->if_bytes / sizeof(struct xfs_bmbt_rec));
+	ASSERT(!isnullstartblock(new->br_startblock));
+
+	XFS_STATS_INC(xs_add_exlist);
+
+#define	LEFT		r[0]
+#define	RIGHT		r[1]
+#define	PREV		r[2]
+
+	/*
+	 * Set up a bunch of variables to make the tests simpler.
+	 */
+	error = 0;
+	ep = xfs_iext_get_ext(ifp, *idx);
+	xfs_bmbt_get_all(ep, &PREV);
+	newext = new->br_state;
+	oldext = (newext == XFS_EXT_UNWRITTEN) ?
+		XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
+	ASSERT(PREV.br_state == oldext);
+	new_endoff = new->br_startoff + new->br_blockcount;
+	ASSERT(PREV.br_startoff <= new->br_startoff);
+	ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
+
+	/*
+	 * Set flags determining what part of the previous oldext allocation
+	 * extent is being replaced by a newext allocation.
+	 */
+	if (PREV.br_startoff == new->br_startoff)
+		state |= BMAP_LEFT_FILLING;
+	if (PREV.br_startoff + PREV.br_blockcount == new_endoff)
+		state |= BMAP_RIGHT_FILLING;
+
+	/*
+	 * Check and set flags if this segment has a left neighbor.
+	 * Don't set contiguous if the combined extent would be too large.
+	 */
+	if (*idx > 0) {
+		state |= BMAP_LEFT_VALID;
+		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx - 1), &LEFT);
+
+		if (isnullstartblock(LEFT.br_startblock))
+			state |= BMAP_LEFT_DELAY;
+	}
+
+	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
+	    LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
+	    LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
+	    LEFT.br_state == newext &&
+	    LEFT.br_blockcount + new->br_blockcount <= MAXEXTLEN)
+		state |= BMAP_LEFT_CONTIG;
+
+	/*
+	 * Check and set flags if this segment has a right neighbor.
+	 * Don't set contiguous if the combined extent would be too large.
+	 * Also check for all-three-contiguous being too large.
+	 */
+	if (*idx < ip->i_df.if_bytes / (uint)sizeof(xfs_bmbt_rec_t) - 1) {
+		state |= BMAP_RIGHT_VALID;
+		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx + 1), &RIGHT);
+		if (isnullstartblock(RIGHT.br_startblock))
+			state |= BMAP_RIGHT_DELAY;
+	}
+
+	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
+	    new_endoff == RIGHT.br_startoff &&
+	    new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
+	    newext == RIGHT.br_state &&
+	    new->br_blockcount + RIGHT.br_blockcount <= MAXEXTLEN &&
+	    ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
+		       BMAP_RIGHT_FILLING)) !=
+		      (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
+		       BMAP_RIGHT_FILLING) ||
+	     LEFT.br_blockcount + new->br_blockcount + RIGHT.br_blockcount
+			<= MAXEXTLEN))
+		state |= BMAP_RIGHT_CONTIG;
+
+	/*
+	 * Switch out based on the FILLING and CONTIG state bits.
+	 */
+	switch (state & (BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
+			 BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG)) {
+	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG |
+	     BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
+		/*
+		 * Setting all of a previous oldext extent to newext.
+		 * The left and right neighbors are both contiguous with new.
+		 */
+		--*idx;
+
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx),
+			LEFT.br_blockcount + PREV.br_blockcount +
+			RIGHT.br_blockcount);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		xfs_iext_remove(ip, *idx + 1, 2, state);
+		ip->i_d.di_nextents -= 2;
+		if (cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			if ((error = xfs_bmbt_lookup_eq(cur, RIGHT.br_startoff,
+					RIGHT.br_startblock,
+					RIGHT.br_blockcount, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_btree_delete(cur, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_btree_decrement(cur, 0, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_btree_delete(cur, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_btree_decrement(cur, 0, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_bmbt_update(cur, LEFT.br_startoff,
+				LEFT.br_startblock,
+				LEFT.br_blockcount + PREV.br_blockcount +
+				RIGHT.br_blockcount, LEFT.br_state)))
+				goto done;
+		}
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
+		/*
+		 * Setting all of a previous oldext extent to newext.
+		 * The left neighbor is contiguous, the right is not.
+		 */
+		--*idx;
+
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx),
+			LEFT.br_blockcount + PREV.br_blockcount);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		xfs_iext_remove(ip, *idx + 1, 1, state);
+		ip->i_d.di_nextents--;
+		if (cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
+					PREV.br_startblock, PREV.br_blockcount,
+					&i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_btree_delete(cur, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_btree_decrement(cur, 0, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_bmbt_update(cur, LEFT.br_startoff,
+				LEFT.br_startblock,
+				LEFT.br_blockcount + PREV.br_blockcount,
+				LEFT.br_state)))
+				goto done;
+		}
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
+		/*
+		 * Setting all of a previous oldext extent to newext.
+		 * The right neighbor is contiguous, the left is not.
+		 */
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep,
+			PREV.br_blockcount + RIGHT.br_blockcount);
+		xfs_bmbt_set_state(ep, newext);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		xfs_iext_remove(ip, *idx + 1, 1, state);
+		ip->i_d.di_nextents--;
+		if (cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			if ((error = xfs_bmbt_lookup_eq(cur, RIGHT.br_startoff,
+					RIGHT.br_startblock,
+					RIGHT.br_blockcount, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_btree_delete(cur, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_btree_decrement(cur, 0, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_bmbt_update(cur, new->br_startoff,
+				new->br_startblock,
+				new->br_blockcount + RIGHT.br_blockcount,
+				newext)))
+				goto done;
+		}
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
+		/*
+		 * Setting all of a previous oldext extent to newext.
+		 * Neither the left nor right neighbors are contiguous with
+		 * the new one.
+		 */
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_state(ep, newext);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		if (cur == NULL)
+			rval = XFS_ILOG_DEXT;
+		else {
+			rval = 0;
+			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
+					new->br_startblock, new->br_blockcount,
+					&i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_bmbt_update(cur, new->br_startoff,
+				new->br_startblock, new->br_blockcount,
+				newext)))
+				goto done;
+		}
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG:
+		/*
+		 * Setting the first part of a previous oldext extent to newext.
+		 * The left neighbor is contiguous.
+		 */
+		trace_xfs_bmap_pre_update(ip, *idx - 1, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx - 1),
+			LEFT.br_blockcount + new->br_blockcount);
+		xfs_bmbt_set_startoff(ep,
+			PREV.br_startoff + new->br_blockcount);
+		trace_xfs_bmap_post_update(ip, *idx - 1, state, _THIS_IP_);
+
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_startblock(ep,
+			new->br_startblock + new->br_blockcount);
+		xfs_bmbt_set_blockcount(ep,
+			PREV.br_blockcount - new->br_blockcount);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		--*idx;
+
+		if (cur == NULL)
+			rval = XFS_ILOG_DEXT;
+		else {
+			rval = 0;
+			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
+					PREV.br_startblock, PREV.br_blockcount,
+					&i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_bmbt_update(cur,
+				PREV.br_startoff + new->br_blockcount,
+				PREV.br_startblock + new->br_blockcount,
+				PREV.br_blockcount - new->br_blockcount,
+				oldext)))
+				goto done;
+			if ((error = xfs_btree_decrement(cur, 0, &i)))
+				goto done;
+			error = xfs_bmbt_update(cur, LEFT.br_startoff,
+				LEFT.br_startblock,
+				LEFT.br_blockcount + new->br_blockcount,
+				LEFT.br_state);
+			if (error)
+				goto done;
+		}
+		break;
+
+	case BMAP_LEFT_FILLING:
+		/*
+		 * Setting the first part of a previous oldext extent to newext.
+		 * The left neighbor is not contiguous.
+		 */
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		ASSERT(ep && xfs_bmbt_get_state(ep) == oldext);
+		xfs_bmbt_set_startoff(ep, new_endoff);
+		xfs_bmbt_set_blockcount(ep,
+			PREV.br_blockcount - new->br_blockcount);
+		xfs_bmbt_set_startblock(ep,
+			new->br_startblock + new->br_blockcount);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		xfs_iext_insert(ip, *idx, 1, new, state);
+		ip->i_d.di_nextents++;
+		if (cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
+					PREV.br_startblock, PREV.br_blockcount,
+					&i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_bmbt_update(cur,
+				PREV.br_startoff + new->br_blockcount,
+				PREV.br_startblock + new->br_blockcount,
+				PREV.br_blockcount - new->br_blockcount,
+				oldext)))
+				goto done;
+			cur->bc_rec.b = *new;
+			if ((error = xfs_btree_insert(cur, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		}
+		break;
+
+	case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
+		/*
+		 * Setting the last part of a previous oldext extent to newext.
+		 * The right neighbor is contiguous with the new allocation.
+		 */
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep,
+			PREV.br_blockcount - new->br_blockcount);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		++*idx;
+
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, *idx),
+			new->br_startoff, new->br_startblock,
+			new->br_blockcount + RIGHT.br_blockcount, newext);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		if (cur == NULL)
+			rval = XFS_ILOG_DEXT;
+		else {
+			rval = 0;
+			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
+					PREV.br_startblock,
+					PREV.br_blockcount, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_bmbt_update(cur, PREV.br_startoff,
+				PREV.br_startblock,
+				PREV.br_blockcount - new->br_blockcount,
+				oldext)))
+				goto done;
+			if ((error = xfs_btree_increment(cur, 0, &i)))
+				goto done;
+			if ((error = xfs_bmbt_update(cur, new->br_startoff,
+				new->br_startblock,
+				new->br_blockcount + RIGHT.br_blockcount,
+				newext)))
+				goto done;
+		}
+		break;
+
+	case BMAP_RIGHT_FILLING:
+		/*
+		 * Setting the last part of a previous oldext extent to newext.
+		 * The right neighbor is not contiguous.
+		 */
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep,
+			PREV.br_blockcount - new->br_blockcount);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		++*idx;
+		xfs_iext_insert(ip, *idx, 1, new, state);
+
+		ip->i_d.di_nextents++;
+		if (cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
+					PREV.br_startblock, PREV.br_blockcount,
+					&i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			if ((error = xfs_bmbt_update(cur, PREV.br_startoff,
+				PREV.br_startblock,
+				PREV.br_blockcount - new->br_blockcount,
+				oldext)))
+				goto done;
+			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
+					new->br_startblock, new->br_blockcount,
+					&i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
+			cur->bc_rec.b.br_state = XFS_EXT_NORM;
+			if ((error = xfs_btree_insert(cur, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		}
+		break;
+
+	case 0:
+		/*
+		 * Setting the middle part of a previous oldext extent to
+		 * newext.  Contiguity is impossible here.
+		 * One extent becomes three extents.
+		 */
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep,
+			new->br_startoff - PREV.br_startoff);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		r[0] = *new;
+		r[1].br_startoff = new_endoff;
+		r[1].br_blockcount =
+			PREV.br_startoff + PREV.br_blockcount - new_endoff;
+		r[1].br_startblock = new->br_startblock + new->br_blockcount;
+		r[1].br_state = oldext;
+
+		++*idx;
+		xfs_iext_insert(ip, *idx, 2, &r[0], state);
+
+		ip->i_d.di_nextents += 2;
+		if (cur == NULL)
+			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
+		else {
+			rval = XFS_ILOG_CORE;
+			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
+					PREV.br_startblock, PREV.br_blockcount,
+					&i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			/* new right extent - oldext */
+			if ((error = xfs_bmbt_update(cur, r[1].br_startoff,
+				r[1].br_startblock, r[1].br_blockcount,
+				r[1].br_state)))
+				goto done;
+			/* new left extent - oldext */
+			cur->bc_rec.b = PREV;
+			cur->bc_rec.b.br_blockcount =
+				new->br_startoff - PREV.br_startoff;
+			if ((error = xfs_btree_insert(cur, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			/*
+			 * Reset the cursor to the position of the new extent
+			 * we are about to insert as we can't trust it after
+			 * the previous insert.
+			 */
+			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
+					new->br_startblock, new->br_blockcount,
+					&i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
+			/* new middle extent - newext */
+			cur->bc_rec.b.br_state = new->br_state;
+			if ((error = xfs_btree_insert(cur, &i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		}
+		break;
+
+	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_CONTIG:
+	case BMAP_RIGHT_FILLING | BMAP_LEFT_CONTIG:
+	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+	case BMAP_LEFT_CONTIG:
+	case BMAP_RIGHT_CONTIG:
+		/*
+		 * These cases are all impossible.
+		 */
+		ASSERT(0);
+	}
+
+	/* convert to a btree if necessary */
+	if (xfs_bmap_needs_btree(ip, XFS_DATA_FORK)) {
+		int	tmp_logflags;	/* partial log flag return val */
+
+		ASSERT(cur == NULL);
+		error = xfs_bmap_extents_to_btree(tp, ip, first, flist, &cur,
+				0, &tmp_logflags, XFS_DATA_FORK);
+		*logflagsp |= tmp_logflags;
+		if (error)
+			goto done;
+	}
+
+	/* clear out the allocated field, done with it now in any case. */
+	if (cur) {
+		cur->bc_private.b.allocated = 0;
+		*curp = cur;
+	}
+
+	xfs_bmap_check_leaf_extents(*curp, ip, XFS_DATA_FORK);
+done:
+	*logflagsp |= rval;
+	return error;
+#undef	LEFT
+#undef	RIGHT
+#undef	PREV
+}
+
+/*
+ * Convert a hole to a delayed allocation.
+ */
+STATIC void
+xfs_bmap_add_extent_hole_delay(
+	xfs_inode_t		*ip,	/* incore inode pointer */
+	xfs_extnum_t		*idx,	/* extent number to update/insert */
+	xfs_bmbt_irec_t		*new)	/* new data to add to file extents */
+{
+	xfs_ifork_t		*ifp;	/* inode fork pointer */
+	xfs_bmbt_irec_t		left;	/* left neighbor extent entry */
+	xfs_filblks_t		newlen=0;	/* new indirect size */
+	xfs_filblks_t		oldlen=0;	/* old indirect size */
+	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
+	int			state;  /* state bits, accessed thru macros */
+	xfs_filblks_t		temp=0;	/* temp for indirect calculations */
+
+	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+	state = 0;
+	ASSERT(isnullstartblock(new->br_startblock));
+
+	/*
+	 * Check and set flags if this segment has a left neighbor
+	 */
+	if (*idx > 0) {
+		state |= BMAP_LEFT_VALID;
+		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx - 1), &left);
+
+		if (isnullstartblock(left.br_startblock))
+			state |= BMAP_LEFT_DELAY;
+	}
+
+	/*
+	 * Check and set flags if the current (right) segment exists.
+	 * If it doesn't exist, we're converting the hole at end-of-file.
+	 */
+	if (*idx < ip->i_df.if_bytes / (uint)sizeof(xfs_bmbt_rec_t)) {
+		state |= BMAP_RIGHT_VALID;
+		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx), &right);
+
+		if (isnullstartblock(right.br_startblock))
+			state |= BMAP_RIGHT_DELAY;
+	}
+
+	/*
+	 * Set contiguity flags on the left and right neighbors.
+	 * Don't let extents get too large, even if the pieces are contiguous.
+	 */
+	if ((state & BMAP_LEFT_VALID) && (state & BMAP_LEFT_DELAY) &&
+	    left.br_startoff + left.br_blockcount == new->br_startoff &&
+	    left.br_blockcount + new->br_blockcount <= MAXEXTLEN)
+		state |= BMAP_LEFT_CONTIG;
+
+	if ((state & BMAP_RIGHT_VALID) && (state & BMAP_RIGHT_DELAY) &&
+	    new->br_startoff + new->br_blockcount == right.br_startoff &&
+	    new->br_blockcount + right.br_blockcount <= MAXEXTLEN &&
+	    (!(state & BMAP_LEFT_CONTIG) ||
+	     (left.br_blockcount + new->br_blockcount +
+	      right.br_blockcount <= MAXEXTLEN)))
+		state |= BMAP_RIGHT_CONTIG;
+
+	/*
+	 * Switch out based on the contiguity flags.
+	 */
+	switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
+	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+		/*
+		 * New allocation is contiguous with delayed allocations
+		 * on the left and on the right.
+		 * Merge all three into a single extent record.
+		 */
+		--*idx;
+		temp = left.br_blockcount + new->br_blockcount +
+			right.br_blockcount;
+
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx), temp);
+		oldlen = startblockval(left.br_startblock) +
+			startblockval(new->br_startblock) +
+			startblockval(right.br_startblock);
+		newlen = xfs_bmap_worst_indlen(ip, temp);
+		xfs_bmbt_set_startblock(xfs_iext_get_ext(ifp, *idx),
+			nullstartblock((int)newlen));
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+
+		xfs_iext_remove(ip, *idx + 1, 1, state);
+		break;
+
+	case BMAP_LEFT_CONTIG:
+		/*
+		 * New allocation is contiguous with a delayed allocation
+		 * on the left.
+		 * Merge the new allocation with the left neighbor.
+		 */
+		--*idx;
+		temp = left.br_blockcount + new->br_blockcount;
+
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx), temp);
+		oldlen = startblockval(left.br_startblock) +
+			startblockval(new->br_startblock);
+		newlen = xfs_bmap_worst_indlen(ip, temp);
+		xfs_bmbt_set_startblock(xfs_iext_get_ext(ifp, *idx),
+			nullstartblock((int)newlen));
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		break;
+
+	case BMAP_RIGHT_CONTIG:
+		/*
+		 * New allocation is contiguous with a delayed allocation
+		 * on the right.
+		 * Merge the new allocation with the right neighbor.
+		 */
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		temp = new->br_blockcount + right.br_blockcount;
+		oldlen = startblockval(new->br_startblock) +
+			startblockval(right.br_startblock);
+		newlen = xfs_bmap_worst_indlen(ip, temp);
+		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, *idx),
+			new->br_startoff,
+			nullstartblock((int)newlen), temp, right.br_state);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		break;
+
+	case 0:
+		/*
+		 * New allocation is not contiguous with another
+		 * delayed allocation.
+		 * Insert a new entry.
+		 */
+		oldlen = newlen = 0;
+		xfs_iext_insert(ip, *idx, 1, new, state);
+		break;
+	}
+	if (oldlen != newlen) {
+		ASSERT(oldlen > newlen);
+		xfs_mod_fdblocks(ip->i_mount, (int64_t)(oldlen - newlen),
+				 false);
+		/*
+		 * Nothing to do for disk quota accounting here.
+		 */
+	}
+}
+
+/*
+ * Convert a hole to a real allocation.
+ */
+STATIC int				/* error */
+xfs_bmap_add_extent_hole_real(
+	struct xfs_bmalloca	*bma,
+	int			whichfork)
+{
+	struct xfs_bmbt_irec	*new = &bma->got;
+	int			error;	/* error return value */
+	int			i;	/* temp state */
+	xfs_ifork_t		*ifp;	/* inode fork pointer */
+	xfs_bmbt_irec_t		left;	/* left neighbor extent entry */
+	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
+	int			rval=0;	/* return value (logging flags) */
+	int			state;	/* state bits, accessed thru macros */
+	struct xfs_mount	*mp;
+
+	mp = bma->tp ? bma->tp->t_mountp : NULL;
+	ifp = XFS_IFORK_PTR(bma->ip, whichfork);
+
+	ASSERT(bma->idx >= 0);
+	ASSERT(bma->idx <= ifp->if_bytes / sizeof(struct xfs_bmbt_rec));
+	ASSERT(!isnullstartblock(new->br_startblock));
+	ASSERT(!bma->cur ||
+	       !(bma->cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL));
+
+	XFS_STATS_INC(xs_add_exlist);
+
+	state = 0;
+	if (whichfork == XFS_ATTR_FORK)
+		state |= BMAP_ATTRFORK;
+
+	/*
+	 * Check and set flags if this segment has a left neighbor.
+	 */
+	if (bma->idx > 0) {
+		state |= BMAP_LEFT_VALID;
+		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx - 1), &left);
+		if (isnullstartblock(left.br_startblock))
+			state |= BMAP_LEFT_DELAY;
+	}
+
+	/*
+	 * Check and set flags if this segment has a current value.
+	 * Not true if we're inserting into the "hole" at eof.
+	 */
+	if (bma->idx < ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t)) {
+		state |= BMAP_RIGHT_VALID;
+		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx), &right);
+		if (isnullstartblock(right.br_startblock))
+			state |= BMAP_RIGHT_DELAY;
+	}
+
+	/*
+	 * We're inserting a real allocation between "left" and "right".
+	 * Set the contiguity flags.  Don't let extents get too large.
+	 */
+	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
+	    left.br_startoff + left.br_blockcount == new->br_startoff &&
+	    left.br_startblock + left.br_blockcount == new->br_startblock &&
+	    left.br_state == new->br_state &&
+	    left.br_blockcount + new->br_blockcount <= MAXEXTLEN)
+		state |= BMAP_LEFT_CONTIG;
+
+	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
+	    new->br_startoff + new->br_blockcount == right.br_startoff &&
+	    new->br_startblock + new->br_blockcount == right.br_startblock &&
+	    new->br_state == right.br_state &&
+	    new->br_blockcount + right.br_blockcount <= MAXEXTLEN &&
+	    (!(state & BMAP_LEFT_CONTIG) ||
+	     left.br_blockcount + new->br_blockcount +
+	     right.br_blockcount <= MAXEXTLEN))
+		state |= BMAP_RIGHT_CONTIG;
+
+	error = 0;
+	/*
+	 * Select which case we're in here, and implement it.
+	 */
+	switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
+	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+		/*
+		 * New allocation is contiguous with real allocations on the
+		 * left and on the right.
+		 * Merge all three into a single extent record.
+		 */
+		--bma->idx;
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, bma->idx),
+			left.br_blockcount + new->br_blockcount +
+			right.br_blockcount);
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		xfs_iext_remove(bma->ip, bma->idx + 1, 1, state);
+
+		XFS_IFORK_NEXT_SET(bma->ip, whichfork,
+			XFS_IFORK_NEXTENTS(bma->ip, whichfork) - 1);
+		if (bma->cur == NULL) {
+			rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
+		} else {
+			rval = XFS_ILOG_CORE;
+			error = xfs_bmbt_lookup_eq(bma->cur, right.br_startoff,
+					right.br_startblock, right.br_blockcount,
+					&i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_btree_delete(bma->cur, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_btree_decrement(bma->cur, 0, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_bmbt_update(bma->cur, left.br_startoff,
+					left.br_startblock,
+					left.br_blockcount +
+						new->br_blockcount +
+						right.br_blockcount,
+					left.br_state);
+			if (error)
+				goto done;
+		}
+		break;
+
+	case BMAP_LEFT_CONTIG:
+		/*
+		 * New allocation is contiguous with a real allocation
+		 * on the left.
+		 * Merge the new allocation with the left neighbor.
+		 */
+		--bma->idx;
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, bma->idx),
+			left.br_blockcount + new->br_blockcount);
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		if (bma->cur == NULL) {
+			rval = xfs_ilog_fext(whichfork);
+		} else {
+			rval = 0;
+			error = xfs_bmbt_lookup_eq(bma->cur, left.br_startoff,
+					left.br_startblock, left.br_blockcount,
+					&i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_bmbt_update(bma->cur, left.br_startoff,
+					left.br_startblock,
+					left.br_blockcount +
+						new->br_blockcount,
+					left.br_state);
+			if (error)
+				goto done;
+		}
+		break;
+
+	case BMAP_RIGHT_CONTIG:
+		/*
+		 * New allocation is contiguous with a real allocation
+		 * on the right.
+		 * Merge the new allocation with the right neighbor.
+		 */
+		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, bma->idx),
+			new->br_startoff, new->br_startblock,
+			new->br_blockcount + right.br_blockcount,
+			right.br_state);
+		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+
+		if (bma->cur == NULL) {
+			rval = xfs_ilog_fext(whichfork);
+		} else {
+			rval = 0;
+			error = xfs_bmbt_lookup_eq(bma->cur,
+					right.br_startoff,
+					right.br_startblock,
+					right.br_blockcount, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			error = xfs_bmbt_update(bma->cur, new->br_startoff,
+					new->br_startblock,
+					new->br_blockcount +
+						right.br_blockcount,
+					right.br_state);
+			if (error)
+				goto done;
+		}
+		break;
+
+	case 0:
+		/*
+		 * New allocation is not contiguous with another
+		 * real allocation.
+		 * Insert a new entry.
+		 */
+		xfs_iext_insert(bma->ip, bma->idx, 1, new, state);
+		XFS_IFORK_NEXT_SET(bma->ip, whichfork,
+			XFS_IFORK_NEXTENTS(bma->ip, whichfork) + 1);
+		if (bma->cur == NULL) {
+			rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
+		} else {
+			rval = XFS_ILOG_CORE;
+			error = xfs_bmbt_lookup_eq(bma->cur,
+					new->br_startoff,
+					new->br_startblock,
+					new->br_blockcount, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
+			bma->cur->bc_rec.b.br_state = new->br_state;
+			error = xfs_btree_insert(bma->cur, &i);
+			if (error)
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		}
+		break;
+	}
+
+	/* convert to a btree if necessary */
+	if (xfs_bmap_needs_btree(bma->ip, whichfork)) {
+		int	tmp_logflags;	/* partial log flag return val */
+
+		ASSERT(bma->cur == NULL);
+		error = xfs_bmap_extents_to_btree(bma->tp, bma->ip,
+				bma->firstblock, bma->flist, &bma->cur,
+				0, &tmp_logflags, whichfork);
+		bma->logflags |= tmp_logflags;
+		if (error)
+			goto done;
+	}
+
+	/* clear out the allocated field, done with it now in any case. */
+	if (bma->cur)
+		bma->cur->bc_private.b.allocated = 0;
+
+	xfs_bmap_check_leaf_extents(bma->cur, bma->ip, whichfork);
+done:
+	bma->logflags |= rval;
+	return error;
+}
+
+/*
+ * Functions used in the extent read, allocate and remove paths
+ */
+
+/*
+ * Adjust the size of the new extent based on di_extsize and rt extsize.
+ */
+int
+xfs_bmap_extsize_align(
+	xfs_mount_t	*mp,
+	xfs_bmbt_irec_t	*gotp,		/* next extent pointer */
+	xfs_bmbt_irec_t	*prevp,		/* previous extent pointer */
+	xfs_extlen_t	extsz,		/* align to this extent size */
+	int		rt,		/* is this a realtime inode? */
+	int		eof,		/* is extent at end-of-file? */
+	int		delay,		/* creating delalloc extent? */
+	int		convert,	/* overwriting unwritten extent? */
+	xfs_fileoff_t	*offp,		/* in/out: aligned offset */
+	xfs_extlen_t	*lenp)		/* in/out: aligned length */
+{
+	xfs_fileoff_t	orig_off;	/* original offset */
+	xfs_extlen_t	orig_alen;	/* original length */
+	xfs_fileoff_t	orig_end;	/* original off+len */
+	xfs_fileoff_t	nexto;		/* next file offset */
+	xfs_fileoff_t	prevo;		/* previous file offset */
+	xfs_fileoff_t	align_off;	/* temp for offset */
+	xfs_extlen_t	align_alen;	/* temp for length */
+	xfs_extlen_t	temp;		/* temp for calculations */
+
+	if (convert)
+		return 0;
+
+	orig_off = align_off = *offp;
+	orig_alen = align_alen = *lenp;
+	orig_end = orig_off + orig_alen;
+
+	/*
+	 * If this request overlaps an existing extent, then don't
+	 * attempt to perform any additional alignment.
+	 */
+	if (!delay && !eof &&
+	    (orig_off >= gotp->br_startoff) &&
+	    (orig_end <= gotp->br_startoff + gotp->br_blockcount)) {
+		return 0;
+	}
+
+	/*
+	 * If the file offset is unaligned vs. the extent size
+	 * we need to align it.  This will be possible unless
+	 * the file was previously written with a kernel that didn't
+	 * perform this alignment, or if a truncate shot us in the
+	 * foot.
+	 */
+	temp = do_mod(orig_off, extsz);
+	if (temp) {
+		align_alen += temp;
+		align_off -= temp;
+	}
+
+	/* Same adjustment for the end of the requested area. */
+	temp = (align_alen % extsz);
+	if (temp)
+		align_alen += extsz - temp;
+
+	/*
+	 * For large extent hint sizes, the aligned extent might be larger than
+	 * MAXEXTLEN. In that case, reduce the size by an extsz so that it pulls
+	 * the length back under MAXEXTLEN. The outer allocation loops handle
+	 * short allocation just fine, so it is safe to do this. We only want to
+	 * do it when we are forced to, though, because it means more allocation
+	 * operations are required.
+	 */
+	while (align_alen > MAXEXTLEN)
+		align_alen -= extsz;
+	ASSERT(align_alen <= MAXEXTLEN);
+
+	/*
+	 * If the previous block overlaps with this proposed allocation
+	 * then move the start forward without adjusting the length.
+	 */
+	if (prevp->br_startoff != NULLFILEOFF) {
+		if (prevp->br_startblock == HOLESTARTBLOCK)
+			prevo = prevp->br_startoff;
+		else
+			prevo = prevp->br_startoff + prevp->br_blockcount;
+	} else
+		prevo = 0;
+	if (align_off != orig_off && align_off < prevo)
+		align_off = prevo;
+	/*
+	 * If the next block overlaps with this proposed allocation
+	 * then move the start back without adjusting the length,
+	 * but not before offset 0.
+	 * This may of course make the start overlap previous block,
+	 * and if we hit the offset 0 limit then the next block
+	 * can still overlap too.
+	 */
+	if (!eof && gotp->br_startoff != NULLFILEOFF) {
+		if ((delay && gotp->br_startblock == HOLESTARTBLOCK) ||
+		    (!delay && gotp->br_startblock == DELAYSTARTBLOCK))
+			nexto = gotp->br_startoff + gotp->br_blockcount;
+		else
+			nexto = gotp->br_startoff;
+	} else
+		nexto = NULLFILEOFF;
+	if (!eof &&
+	    align_off + align_alen != orig_end &&
+	    align_off + align_alen > nexto)
+		align_off = nexto > align_alen ? nexto - align_alen : 0;
+	/*
+	 * If we're now overlapping the next or previous extent that
+	 * means we can't fit an extsz piece in this hole.  Just move
+	 * the start forward to the first valid spot and set
+	 * the length so we hit the end.
+	 */
+	if (align_off != orig_off && align_off < prevo)
+		align_off = prevo;
+	if (align_off + align_alen != orig_end &&
+	    align_off + align_alen > nexto &&
+	    nexto != NULLFILEOFF) {
+		ASSERT(nexto > prevo);
+		align_alen = nexto - align_off;
+	}
+
+	/*
+	 * If realtime, and the result isn't a multiple of the realtime
+	 * extent size we need to remove blocks until it is.
+	 */
+	if (rt && (temp = (align_alen % mp->m_sb.sb_rextsize))) {
+		/*
+		 * We're not covering the original request, or
+		 * we won't be able to once we fix the length.
+		 */
+		if (orig_off < align_off ||
+		    orig_end > align_off + align_alen ||
+		    align_alen - temp < orig_alen)
+			return -EINVAL;
+		/*
+		 * Try to fix it by moving the start up.
+		 */
+		if (align_off + temp <= orig_off) {
+			align_alen -= temp;
+			align_off += temp;
+		}
+		/*
+		 * Try to fix it by moving the end in.
+		 */
+		else if (align_off + align_alen - temp >= orig_end)
+			align_alen -= temp;
+		/*
+		 * Set the start to the minimum then trim the length.
+		 */
+		else {
+			align_alen -= orig_off - align_off;
+			align_off = orig_off;
+			align_alen -= align_alen % mp->m_sb.sb_rextsize;
+		}
+		/*
+		 * Result doesn't cover the request, fail it.
+		 */
+		if (orig_off < align_off || orig_end > align_off + align_alen)
+			return -EINVAL;
+	} else {
+		ASSERT(orig_off >= align_off);
+		/* see MAXEXTLEN handling above */
+		ASSERT(orig_end <= align_off + align_alen ||
+		       align_alen + extsz > MAXEXTLEN);
+	}
+
+#ifdef DEBUG
+	if (!eof && gotp->br_startoff != NULLFILEOFF)
+		ASSERT(align_off + align_alen <= gotp->br_startoff);
+	if (prevp->br_startoff != NULLFILEOFF)
+		ASSERT(align_off >= prevp->br_startoff + prevp->br_blockcount);
+#endif
+
+	*lenp = align_alen;
+	*offp = align_off;
+	return 0;
+}
+
+#define XFS_ALLOC_GAP_UNITS	4
+
+void
+xfs_bmap_adjacent(
+	struct xfs_bmalloca	*ap)	/* bmap alloc argument struct */
+{
+	xfs_fsblock_t	adjust;		/* adjustment to block numbers */
+	xfs_agnumber_t	fb_agno;	/* ag number of ap->firstblock */
+	xfs_mount_t	*mp;		/* mount point structure */
+	int		nullfb;		/* true if ap->firstblock isn't set */
+	int		rt;		/* true if inode is realtime */
+
+#define	ISVALID(x,y)	\
+	(rt ? \
+		(x) < mp->m_sb.sb_rblocks : \
+		XFS_FSB_TO_AGNO(mp, x) == XFS_FSB_TO_AGNO(mp, y) && \
+		XFS_FSB_TO_AGNO(mp, x) < mp->m_sb.sb_agcount && \
+		XFS_FSB_TO_AGBNO(mp, x) < mp->m_sb.sb_agblocks)
+
+	mp = ap->ip->i_mount;
+	nullfb = *ap->firstblock == NULLFSBLOCK;
+	rt = XFS_IS_REALTIME_INODE(ap->ip) && ap->userdata;
+	fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp, *ap->firstblock);
+	/*
+	 * If allocating at eof, and there's a previous real block,
+	 * try to use its last block as our starting point.
+	 */
+	if (ap->eof && ap->prev.br_startoff != NULLFILEOFF &&
+	    !isnullstartblock(ap->prev.br_startblock) &&
+	    ISVALID(ap->prev.br_startblock + ap->prev.br_blockcount,
+		    ap->prev.br_startblock)) {
+		ap->blkno = ap->prev.br_startblock + ap->prev.br_blockcount;
+		/*
+		 * Adjust for the gap between prevp and us.
+		 */
+		adjust = ap->offset -
+			(ap->prev.br_startoff + ap->prev.br_blockcount);
+		if (adjust &&
+		    ISVALID(ap->blkno + adjust, ap->prev.br_startblock))
+			ap->blkno += adjust;
+	}
+	/*
+	 * If not at eof, then compare the two neighbor blocks.
+	 * Figure out whether either one gives us a good starting point,
+	 * and pick the better one.
+	 */
+	else if (!ap->eof) {
+		xfs_fsblock_t	gotbno;		/* right side block number */
+		xfs_fsblock_t	gotdiff=0;	/* right side difference */
+		xfs_fsblock_t	prevbno;	/* left side block number */
+		xfs_fsblock_t	prevdiff=0;	/* left side difference */
+
+		/*
+		 * If there's a previous (left) block, select a requested
+		 * start block based on it.
+		 */
+		if (ap->prev.br_startoff != NULLFILEOFF &&
+		    !isnullstartblock(ap->prev.br_startblock) &&
+		    (prevbno = ap->prev.br_startblock +
+			       ap->prev.br_blockcount) &&
+		    ISVALID(prevbno, ap->prev.br_startblock)) {
+			/*
+			 * Calculate gap to end of previous block.
+			 */
+			adjust = prevdiff = ap->offset -
+				(ap->prev.br_startoff +
+				 ap->prev.br_blockcount);
+			/*
+			 * Figure the startblock based on the previous block's
+			 * end and the gap size.
+			 * Heuristic!
+			 * If the gap is large relative to the piece we're
+			 * allocating, or using it gives us an invalid block
+			 * number, then just use the end of the previous block.
+			 */
+			if (prevdiff <= XFS_ALLOC_GAP_UNITS * ap->length &&
+			    ISVALID(prevbno + prevdiff,
+				    ap->prev.br_startblock))
+				prevbno += adjust;
+			else
+				prevdiff += adjust;
+			/*
+			 * If the firstblock forbids it, can't use it,
+			 * must use default.
+			 */
+			if (!rt && !nullfb &&
+			    XFS_FSB_TO_AGNO(mp, prevbno) != fb_agno)
+				prevbno = NULLFSBLOCK;
+		}
+		/*
+		 * No previous block or can't follow it, just default.
+		 */
+		else
+			prevbno = NULLFSBLOCK;
+		/*
+		 * If there's a following (right) block, select a requested
+		 * start block based on it.
+		 */
+		if (!isnullstartblock(ap->got.br_startblock)) {
+			/*
+			 * Calculate gap to start of next block.
+			 */
+			adjust = gotdiff = ap->got.br_startoff - ap->offset;
+			/*
+			 * Figure the startblock based on the next block's
+			 * start and the gap size.
+			 */
+			gotbno = ap->got.br_startblock;
+			/*
+			 * Heuristic!
+			 * If the gap is large relative to the piece we're
+			 * allocating, or using it gives us an invalid block
+			 * number, then just use the start of the next block
+			 * offset by our length.
+			 */
+			if (gotdiff <= XFS_ALLOC_GAP_UNITS * ap->length &&
+			    ISVALID(gotbno - gotdiff, gotbno))
+				gotbno -= adjust;
+			else if (ISVALID(gotbno - ap->length, gotbno)) {
+				gotbno -= ap->length;
+				gotdiff += adjust - ap->length;
+			} else
+				gotdiff += adjust;
+			/*
+			 * If the firstblock forbids it, can't use it,
+			 * must use default.
+			 */
+			if (!rt && !nullfb &&
+			    XFS_FSB_TO_AGNO(mp, gotbno) != fb_agno)
+				gotbno = NULLFSBLOCK;
+		}
+		/*
+		 * No next block, just default.
+		 */
+		else
+			gotbno = NULLFSBLOCK;
+		/*
+		 * If both valid, pick the better one, else the only good
+		 * one, else ap->blkno is already set (to 0 or the inode block).
+		 */
+		if (prevbno != NULLFSBLOCK && gotbno != NULLFSBLOCK)
+			ap->blkno = prevdiff <= gotdiff ? prevbno : gotbno;
+		else if (prevbno != NULLFSBLOCK)
+			ap->blkno = prevbno;
+		else if (gotbno != NULLFSBLOCK)
+			ap->blkno = gotbno;
+	}
+#undef ISVALID
+}
+
+static int
+xfs_bmap_longest_free_extent(
+	struct xfs_trans	*tp,
+	xfs_agnumber_t		ag,
+	xfs_extlen_t		*blen,
+	int			*notinit)
+{
+	struct xfs_mount	*mp = tp->t_mountp;
+	struct xfs_perag	*pag;
+	xfs_extlen_t		longest;
+	int			error = 0;
+
+	pag = xfs_perag_get(mp, ag);
+	if (!pag->pagf_init) {
+		error = xfs_alloc_pagf_init(mp, tp, ag, XFS_ALLOC_FLAG_TRYLOCK);
+		if (error)
+			goto out;
+
+		if (!pag->pagf_init) {
+			*notinit = 1;
+			goto out;
+		}
+	}
+
+	longest = xfs_alloc_longest_free_extent(mp, pag);
+	if (*blen < longest)
+		*blen = longest;
+
+out:
+	xfs_perag_put(pag);
+	return error;
+}
+
+static void
+xfs_bmap_select_minlen(
+	struct xfs_bmalloca	*ap,
+	struct xfs_alloc_arg	*args,
+	xfs_extlen_t		*blen,
+	int			notinit)
+{
+	if (notinit || *blen < ap->minlen) {
+		/*
+		 * Since we did a BUF_TRYLOCK above, it is possible that
+		 * there is space for this request.
+		 */
+		args->minlen = ap->minlen;
+	} else if (*blen < args->maxlen) {
+		/*
+		 * If the best seen length is less than the request length,
+		 * use the best as the minimum.
+		 */
+		args->minlen = *blen;
+	} else {
+		/*
+		 * Otherwise we've seen an extent as big as maxlen, use that
+		 * as the minimum.
+		 */
+		args->minlen = args->maxlen;
+	}
+}
+
+STATIC int
+xfs_bmap_btalloc_nullfb(
+	struct xfs_bmalloca	*ap,
+	struct xfs_alloc_arg	*args,
+	xfs_extlen_t		*blen)
+{
+	struct xfs_mount	*mp = ap->ip->i_mount;
+	xfs_agnumber_t		ag, startag;
+	int			notinit = 0;
+	int			error;
+
+	args->type = XFS_ALLOCTYPE_START_BNO;
+	args->total = ap->total;
+
+	startag = ag = XFS_FSB_TO_AGNO(mp, args->fsbno);
+	if (startag == NULLAGNUMBER)
+		startag = ag = 0;
+
+	while (*blen < args->maxlen) {
+		error = xfs_bmap_longest_free_extent(args->tp, ag, blen,
+						     &notinit);
+		if (error)
+			return error;
+
+		if (++ag == mp->m_sb.sb_agcount)
+			ag = 0;
+		if (ag == startag)
+			break;
+	}
+
+	xfs_bmap_select_minlen(ap, args, blen, notinit);
+	return 0;
+}
+
+STATIC int
+xfs_bmap_btalloc_filestreams(
+	struct xfs_bmalloca	*ap,
+	struct xfs_alloc_arg	*args,
+	xfs_extlen_t		*blen)
+{
+	struct xfs_mount	*mp = ap->ip->i_mount;
+	xfs_agnumber_t		ag;
+	int			notinit = 0;
+	int			error;
+
+	args->type = XFS_ALLOCTYPE_NEAR_BNO;
+	args->total = ap->total;
+
+	ag = XFS_FSB_TO_AGNO(mp, args->fsbno);
+	if (ag == NULLAGNUMBER)
+		ag = 0;
+
+	error = xfs_bmap_longest_free_extent(args->tp, ag, blen, &notinit);
+	if (error)
+		return error;
+
+	if (*blen < args->maxlen) {
+		error = xfs_filestream_new_ag(ap, &ag);
+		if (error)
+			return error;
+
+		error = xfs_bmap_longest_free_extent(args->tp, ag, blen,
+						     &notinit);
+		if (error)
+			return error;
+
+	}
+
+	xfs_bmap_select_minlen(ap, args, blen, notinit);
+
+	/*
+	 * Set the failure fallback case to look in the selected AG as stream
+	 * may have moved.
+	 */
+	ap->blkno = args->fsbno = XFS_AGB_TO_FSB(mp, ag, 0);
+	return 0;
+}
+
+STATIC int
+xfs_bmap_btalloc(
+	struct xfs_bmalloca	*ap)	/* bmap alloc argument struct */
+{
+	xfs_mount_t	*mp;		/* mount point structure */
+	xfs_alloctype_t	atype = 0;	/* type for allocation routines */
+	xfs_extlen_t	align;		/* minimum allocation alignment */
+	xfs_agnumber_t	fb_agno;	/* ag number of ap->firstblock */
+	xfs_agnumber_t	ag;
+	xfs_alloc_arg_t	args;
+	xfs_extlen_t	blen;
+	xfs_extlen_t	nextminlen = 0;
+	int		nullfb;		/* true if ap->firstblock isn't set */
+	int		isaligned;
+	int		tryagain;
+	int		error;
+	int		stripe_align;
+
+	ASSERT(ap->length);
+
+	mp = ap->ip->i_mount;
+
+	/* stripe alignment for allocation is determined by mount parameters */
+	stripe_align = 0;
+	if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC))
+		stripe_align = mp->m_swidth;
+	else if (mp->m_dalign)
+		stripe_align = mp->m_dalign;
+
+	align = ap->userdata ? xfs_get_extsz_hint(ap->ip) : 0;
+	if (unlikely(align)) {
+		error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
+						align, 0, ap->eof, 0, ap->conv,
+						&ap->offset, &ap->length);
+		ASSERT(!error);
+		ASSERT(ap->length);
+	}
+
+
+	nullfb = *ap->firstblock == NULLFSBLOCK;
+	fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp, *ap->firstblock);
+	if (nullfb) {
+		if (ap->userdata && xfs_inode_is_filestream(ap->ip)) {
+			ag = xfs_filestream_lookup_ag(ap->ip);
+			ag = (ag != NULLAGNUMBER) ? ag : 0;
+			ap->blkno = XFS_AGB_TO_FSB(mp, ag, 0);
+		} else {
+			ap->blkno = XFS_INO_TO_FSB(mp, ap->ip->i_ino);
+		}
+	} else
+		ap->blkno = *ap->firstblock;
+
+	xfs_bmap_adjacent(ap);
+
+	/*
+	 * If allowed, use ap->blkno; otherwise must use firstblock since
+	 * it's in the right allocation group.
+	 */
+	if (nullfb || XFS_FSB_TO_AGNO(mp, ap->blkno) == fb_agno)
+		;
+	else
+		ap->blkno = *ap->firstblock;
+	/*
+	 * Normal allocation, done through xfs_alloc_vextent.
+	 */
+	tryagain = isaligned = 0;
+	memset(&args, 0, sizeof(args));
+	args.tp = ap->tp;
+	args.mp = mp;
+	args.fsbno = ap->blkno;
+
+	/* Trim the allocation back to the maximum an AG can fit. */
+	args.maxlen = MIN(ap->length, XFS_ALLOC_AG_MAX_USABLE(mp));
+	args.firstblock = *ap->firstblock;
+	blen = 0;
+	if (nullfb) {
+		/*
+		 * Search for an allocation group with a single extent large
+		 * enough for the request.  If one isn't found, then adjust
+		 * the minimum allocation size to the largest space found.
+		 */
+		if (ap->userdata && xfs_inode_is_filestream(ap->ip))
+			error = xfs_bmap_btalloc_filestreams(ap, &args, &blen);
+		else
+			error = xfs_bmap_btalloc_nullfb(ap, &args, &blen);
+		if (error)
+			return error;
+	} else if (ap->flist->xbf_low) {
+		if (xfs_inode_is_filestream(ap->ip))
+			args.type = XFS_ALLOCTYPE_FIRST_AG;
+		else
+			args.type = XFS_ALLOCTYPE_START_BNO;
+		args.total = args.minlen = ap->minlen;
+	} else {
+		args.type = XFS_ALLOCTYPE_NEAR_BNO;
+		args.total = ap->total;
+		args.minlen = ap->minlen;
+	}
+	/* apply extent size hints if obtained earlier */
+	if (unlikely(align)) {
+		args.prod = align;
+		if ((args.mod = (xfs_extlen_t)do_mod(ap->offset, args.prod)))
+			args.mod = (xfs_extlen_t)(args.prod - args.mod);
+	} else if (mp->m_sb.sb_blocksize >= PAGE_CACHE_SIZE) {
+		args.prod = 1;
+		args.mod = 0;
+	} else {
+		args.prod = PAGE_CACHE_SIZE >> mp->m_sb.sb_blocklog;
+		if ((args.mod = (xfs_extlen_t)(do_mod(ap->offset, args.prod))))
+			args.mod = (xfs_extlen_t)(args.prod - args.mod);
+	}
+	/*
+	 * If we are not low on available data blocks, and the
+	 * underlying logical volume manager is a stripe, and
+	 * the file offset is zero then try to allocate data
+	 * blocks on stripe unit boundary.
+	 * NOTE: ap->aeof is only set if the allocation length
+	 * is >= the stripe unit and the allocation offset is
+	 * at the end of file.
+	 */
+	if (!ap->flist->xbf_low && ap->aeof) {
+		if (!ap->offset) {
+			args.alignment = stripe_align;
+			atype = args.type;
+			isaligned = 1;
+			/*
+			 * Adjust for alignment
+			 */
+			if (blen > args.alignment && blen <= args.maxlen)
+				args.minlen = blen - args.alignment;
+			args.minalignslop = 0;
+		} else {
+			/*
+			 * First try an exact bno allocation.
+			 * If it fails then do a near or start bno
+			 * allocation with alignment turned on.
+			 */
+			atype = args.type;
+			tryagain = 1;
+			args.type = XFS_ALLOCTYPE_THIS_BNO;
+			args.alignment = 1;
+			/*
+			 * Compute the minlen+alignment for the
+			 * next case.  Set slop so that the value
+			 * of minlen+alignment+slop doesn't go up
+			 * between the calls.
+			 */
+			if (blen > stripe_align && blen <= args.maxlen)
+				nextminlen = blen - stripe_align;
+			else
+				nextminlen = args.minlen;
+			if (nextminlen + stripe_align > args.minlen + 1)
+				args.minalignslop =
+					nextminlen + stripe_align -
+					args.minlen - 1;
+			else
+				args.minalignslop = 0;
+		}
+	} else {
+		args.alignment = 1;
+		args.minalignslop = 0;
+	}
+	args.minleft = ap->minleft;
+	args.wasdel = ap->wasdel;
+	args.isfl = 0;
+	args.userdata = ap->userdata;
+	if ((error = xfs_alloc_vextent(&args)))
+		return error;
+	if (tryagain && args.fsbno == NULLFSBLOCK) {
+		/*
+		 * Exact allocation failed. Now try with alignment
+		 * turned on.
+		 */
+		args.type = atype;
+		args.fsbno = ap->blkno;
+		args.alignment = stripe_align;
+		args.minlen = nextminlen;
+		args.minalignslop = 0;
+		isaligned = 1;
+		if ((error = xfs_alloc_vextent(&args)))
+			return error;
+	}
+	if (isaligned && args.fsbno == NULLFSBLOCK) {
+		/*
+		 * allocation failed, so turn off alignment and
+		 * try again.
+		 */
+		args.type = atype;
+		args.fsbno = ap->blkno;
+		args.alignment = 0;
+		if ((error = xfs_alloc_vextent(&args)))
+			return error;
+	}
+	if (args.fsbno == NULLFSBLOCK && nullfb &&
+	    args.minlen > ap->minlen) {
+		args.minlen = ap->minlen;
+		args.type = XFS_ALLOCTYPE_START_BNO;
+		args.fsbno = ap->blkno;
+		if ((error = xfs_alloc_vextent(&args)))
+			return error;
+	}
+	if (args.fsbno == NULLFSBLOCK && nullfb) {
+		args.fsbno = 0;
+		args.type = XFS_ALLOCTYPE_FIRST_AG;
+		args.total = ap->minlen;
+		args.minleft = 0;
+		if ((error = xfs_alloc_vextent(&args)))
+			return error;
+		ap->flist->xbf_low = 1;
+	}
+	if (args.fsbno != NULLFSBLOCK) {
+		/*
+		 * check the allocation happened at the same or higher AG than
+		 * the first block that was allocated.
+		 */
+		ASSERT(*ap->firstblock == NULLFSBLOCK ||
+		       XFS_FSB_TO_AGNO(mp, *ap->firstblock) ==
+		       XFS_FSB_TO_AGNO(mp, args.fsbno) ||
+		       (ap->flist->xbf_low &&
+			XFS_FSB_TO_AGNO(mp, *ap->firstblock) <
+			XFS_FSB_TO_AGNO(mp, args.fsbno)));
+
+		ap->blkno = args.fsbno;
+		if (*ap->firstblock == NULLFSBLOCK)
+			*ap->firstblock = args.fsbno;
+		ASSERT(nullfb || fb_agno == args.agno ||
+		       (ap->flist->xbf_low && fb_agno < args.agno));
+		ap->length = args.len;
+		ap->ip->i_d.di_nblocks += args.len;
+		xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
+		if (ap->wasdel)
+			ap->ip->i_delayed_blks -= args.len;
+		/*
+		 * Adjust the disk quota also. This was reserved
+		 * earlier.
+		 */
+		xfs_trans_mod_dquot_byino(ap->tp, ap->ip,
+			ap->wasdel ? XFS_TRANS_DQ_DELBCOUNT :
+					XFS_TRANS_DQ_BCOUNT,
+			(long) args.len);
+	} else {
+		ap->blkno = NULLFSBLOCK;
+		ap->length = 0;
+	}
+	return 0;
+}
+
+/*
+ * xfs_bmap_alloc is called by xfs_bmapi to allocate an extent for a file.
+ * It figures out where to ask the underlying allocator to put the new extent.
+ */
+STATIC int
+xfs_bmap_alloc(
+	struct xfs_bmalloca	*ap)	/* bmap alloc argument struct */
+{
+	if (XFS_IS_REALTIME_INODE(ap->ip) && ap->userdata)
+		return xfs_bmap_rtalloc(ap);
+	return xfs_bmap_btalloc(ap);
+}
+
+/*
+ * Trim the returned map to the required bounds
+ */
+STATIC void
+xfs_bmapi_trim_map(
+	struct xfs_bmbt_irec	*mval,
+	struct xfs_bmbt_irec	*got,
+	xfs_fileoff_t		*bno,
+	xfs_filblks_t		len,
+	xfs_fileoff_t		obno,
+	xfs_fileoff_t		end,
+	int			n,
+	int			flags)
+{
+	if ((flags & XFS_BMAPI_ENTIRE) ||
+	    got->br_startoff + got->br_blockcount <= obno) {
+		*mval = *got;
+		if (isnullstartblock(got->br_startblock))
+			mval->br_startblock = DELAYSTARTBLOCK;
+		return;
+	}
+
+	if (obno > *bno)
+		*bno = obno;
+	ASSERT((*bno >= obno) || (n == 0));
+	ASSERT(*bno < end);
+	mval->br_startoff = *bno;
+	if (isnullstartblock(got->br_startblock))
+		mval->br_startblock = DELAYSTARTBLOCK;
+	else
+		mval->br_startblock = got->br_startblock +
+					(*bno - got->br_startoff);
+	/*
+	 * Return the minimum of what we got and what we asked for for
+	 * the length.  We can use the len variable here because it is
+	 * modified below and we could have been there before coming
+	 * here if the first part of the allocation didn't overlap what
+	 * was asked for.
+	 */
+	mval->br_blockcount = XFS_FILBLKS_MIN(end - *bno,
+			got->br_blockcount - (*bno - got->br_startoff));
+	mval->br_state = got->br_state;
+	ASSERT(mval->br_blockcount <= len);
+	return;
+}
+
+/*
+ * Update and validate the extent map to return
+ */
+STATIC void
+xfs_bmapi_update_map(
+	struct xfs_bmbt_irec	**map,
+	xfs_fileoff_t		*bno,
+	xfs_filblks_t		*len,
+	xfs_fileoff_t		obno,
+	xfs_fileoff_t		end,
+	int			*n,
+	int			flags)
+{
+	xfs_bmbt_irec_t	*mval = *map;
+
+	ASSERT((flags & XFS_BMAPI_ENTIRE) ||
+	       ((mval->br_startoff + mval->br_blockcount) <= end));
+	ASSERT((flags & XFS_BMAPI_ENTIRE) || (mval->br_blockcount <= *len) ||
+	       (mval->br_startoff < obno));
+
+	*bno = mval->br_startoff + mval->br_blockcount;
+	*len = end - *bno;
+	if (*n > 0 && mval->br_startoff == mval[-1].br_startoff) {
+		/* update previous map with new information */
+		ASSERT(mval->br_startblock == mval[-1].br_startblock);
+		ASSERT(mval->br_blockcount > mval[-1].br_blockcount);
+		ASSERT(mval->br_state == mval[-1].br_state);
+		mval[-1].br_blockcount = mval->br_blockcount;
+		mval[-1].br_state = mval->br_state;
+	} else if (*n > 0 && mval->br_startblock != DELAYSTARTBLOCK &&
+		   mval[-1].br_startblock != DELAYSTARTBLOCK &&
+		   mval[-1].br_startblock != HOLESTARTBLOCK &&
+		   mval->br_startblock == mval[-1].br_startblock +
+					  mval[-1].br_blockcount &&
+		   ((flags & XFS_BMAPI_IGSTATE) ||
+			mval[-1].br_state == mval->br_state)) {
+		ASSERT(mval->br_startoff ==
+		       mval[-1].br_startoff + mval[-1].br_blockcount);
+		mval[-1].br_blockcount += mval->br_blockcount;
+	} else if (*n > 0 &&
+		   mval->br_startblock == DELAYSTARTBLOCK &&
+		   mval[-1].br_startblock == DELAYSTARTBLOCK &&
+		   mval->br_startoff ==
+		   mval[-1].br_startoff + mval[-1].br_blockcount) {
+		mval[-1].br_blockcount += mval->br_blockcount;
+		mval[-1].br_state = mval->br_state;
+	} else if (!((*n == 0) &&
+		     ((mval->br_startoff + mval->br_blockcount) <=
+		      obno))) {
+		mval++;
+		(*n)++;
+	}
+	*map = mval;
+}
+
+/*
+ * Map file blocks to filesystem blocks without allocation.
+ */
+int
+xfs_bmapi_read(
+	struct xfs_inode	*ip,
+	xfs_fileoff_t		bno,
+	xfs_filblks_t		len,
+	struct xfs_bmbt_irec	*mval,
+	int			*nmap,
+	int			flags)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_ifork	*ifp;
+	struct xfs_bmbt_irec	got;
+	struct xfs_bmbt_irec	prev;
+	xfs_fileoff_t		obno;
+	xfs_fileoff_t		end;
+	xfs_extnum_t		lastx;
+	int			error;
+	int			eof;
+	int			n = 0;
+	int			whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
+						XFS_ATTR_FORK : XFS_DATA_FORK;
+
+	ASSERT(*nmap >= 1);
+	ASSERT(!(flags & ~(XFS_BMAPI_ATTRFORK|XFS_BMAPI_ENTIRE|
+			   XFS_BMAPI_IGSTATE)));
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED|XFS_ILOCK_EXCL));
+
+	if (unlikely(XFS_TEST_ERROR(
+	    (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+	     XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE),
+	     mp, XFS_ERRTAG_BMAPIFORMAT, XFS_RANDOM_BMAPIFORMAT))) {
+		XFS_ERROR_REPORT("xfs_bmapi_read", XFS_ERRLEVEL_LOW, mp);
+		return -EFSCORRUPTED;
+	}
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
+	XFS_STATS_INC(xs_blk_mapr);
+
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		error = xfs_iread_extents(NULL, ip, whichfork);
+		if (error)
+			return error;
+	}
+
+	xfs_bmap_search_extents(ip, bno, whichfork, &eof, &lastx, &got, &prev);
+	end = bno + len;
+	obno = bno;
+
+	while (bno < end && n < *nmap) {
+		/* Reading past eof, act as though there's a hole up to end. */
+		if (eof)
+			got.br_startoff = end;
+		if (got.br_startoff > bno) {
+			/* Reading in a hole.  */
+			mval->br_startoff = bno;
+			mval->br_startblock = HOLESTARTBLOCK;
+			mval->br_blockcount =
+				XFS_FILBLKS_MIN(len, got.br_startoff - bno);
+			mval->br_state = XFS_EXT_NORM;
+			bno += mval->br_blockcount;
+			len -= mval->br_blockcount;
+			mval++;
+			n++;
+			continue;
+		}
+
+		/* set up the extent map to return. */
+		xfs_bmapi_trim_map(mval, &got, &bno, len, obno, end, n, flags);
+		xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
+
+		/* If we're done, stop now. */
+		if (bno >= end || n >= *nmap)
+			break;
+
+		/* Else go on to the next record. */
+		if (++lastx < ifp->if_bytes / sizeof(xfs_bmbt_rec_t))
+			xfs_bmbt_get_all(xfs_iext_get_ext(ifp, lastx), &got);
+		else
+			eof = 1;
+	}
+	*nmap = n;
+	return 0;
+}
+
+STATIC int
+xfs_bmapi_reserve_delalloc(
+	struct xfs_inode	*ip,
+	xfs_fileoff_t		aoff,
+	xfs_filblks_t		len,
+	struct xfs_bmbt_irec	*got,
+	struct xfs_bmbt_irec	*prev,
+	xfs_extnum_t		*lastx,
+	int			eof)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+	xfs_extlen_t		alen;
+	xfs_extlen_t		indlen;
+	char			rt = XFS_IS_REALTIME_INODE(ip);
+	xfs_extlen_t		extsz;
+	int			error;
+
+	alen = XFS_FILBLKS_MIN(len, MAXEXTLEN);
+	if (!eof)
+		alen = XFS_FILBLKS_MIN(alen, got->br_startoff - aoff);
+
+	/* Figure out the extent size, adjust alen */
+	extsz = xfs_get_extsz_hint(ip);
+	if (extsz) {
+		error = xfs_bmap_extsize_align(mp, got, prev, extsz, rt, eof,
+					       1, 0, &aoff, &alen);
+		ASSERT(!error);
+	}
+
+	if (rt)
+		extsz = alen / mp->m_sb.sb_rextsize;
+
+	/*
+	 * Make a transaction-less quota reservation for delayed allocation
+	 * blocks.  This number gets adjusted later.  We return if we haven't
+	 * allocated blocks already inside this loop.
+	 */
+	error = xfs_trans_reserve_quota_nblks(NULL, ip, (long)alen, 0,
+			rt ? XFS_QMOPT_RES_RTBLKS : XFS_QMOPT_RES_REGBLKS);
+	if (error)
+		return error;
+
+	/*
+	 * Split changing sb for alen and indlen since they could be coming
+	 * from different places.
+	 */
+	indlen = (xfs_extlen_t)xfs_bmap_worst_indlen(ip, alen);
+	ASSERT(indlen > 0);
+
+	if (rt) {
+		error = xfs_mod_frextents(mp, -((int64_t)extsz));
+	} else {
+		error = xfs_mod_fdblocks(mp, -((int64_t)alen), false);
+	}
+
+	if (error)
+		goto out_unreserve_quota;
+
+	error = xfs_mod_fdblocks(mp, -((int64_t)indlen), false);
+	if (error)
+		goto out_unreserve_blocks;
+
+
+	ip->i_delayed_blks += alen;
+
+	got->br_startoff = aoff;
+	got->br_startblock = nullstartblock(indlen);
+	got->br_blockcount = alen;
+	got->br_state = XFS_EXT_NORM;
+	xfs_bmap_add_extent_hole_delay(ip, lastx, got);
+
+	/*
+	 * Update our extent pointer, given that xfs_bmap_add_extent_hole_delay
+	 * might have merged it into one of the neighbouring ones.
+	 */
+	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *lastx), got);
+
+	ASSERT(got->br_startoff <= aoff);
+	ASSERT(got->br_startoff + got->br_blockcount >= aoff + alen);
+	ASSERT(isnullstartblock(got->br_startblock));
+	ASSERT(got->br_state == XFS_EXT_NORM);
+	return 0;
+
+out_unreserve_blocks:
+	if (rt)
+		xfs_mod_frextents(mp, extsz);
+	else
+		xfs_mod_fdblocks(mp, alen, false);
+out_unreserve_quota:
+	if (XFS_IS_QUOTA_ON(mp))
+		xfs_trans_unreserve_quota_nblks(NULL, ip, (long)alen, 0, rt ?
+				XFS_QMOPT_RES_RTBLKS : XFS_QMOPT_RES_REGBLKS);
+	return error;
+}
+
+/*
+ * Map file blocks to filesystem blocks, adding delayed allocations as needed.
+ */
+int
+xfs_bmapi_delay(
+	struct xfs_inode	*ip,	/* incore inode */
+	xfs_fileoff_t		bno,	/* starting file offs. mapped */
+	xfs_filblks_t		len,	/* length to map in file */
+	struct xfs_bmbt_irec	*mval,	/* output: map values */
+	int			*nmap,	/* i/o: mval size/count */
+	int			flags)	/* XFS_BMAPI_... */
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+	struct xfs_bmbt_irec	got;	/* current file extent record */
+	struct xfs_bmbt_irec	prev;	/* previous file extent record */
+	xfs_fileoff_t		obno;	/* old block number (offset) */
+	xfs_fileoff_t		end;	/* end of mapped file region */
+	xfs_extnum_t		lastx;	/* last useful extent number */
+	int			eof;	/* we've hit the end of extents */
+	int			n = 0;	/* current extent index */
+	int			error = 0;
+
+	ASSERT(*nmap >= 1);
+	ASSERT(*nmap <= XFS_BMAP_MAX_NMAP);
+	ASSERT(!(flags & ~XFS_BMAPI_ENTIRE));
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	if (unlikely(XFS_TEST_ERROR(
+	    (XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_EXTENTS &&
+	     XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_BTREE),
+	     mp, XFS_ERRTAG_BMAPIFORMAT, XFS_RANDOM_BMAPIFORMAT))) {
+		XFS_ERROR_REPORT("xfs_bmapi_delay", XFS_ERRLEVEL_LOW, mp);
+		return -EFSCORRUPTED;
+	}
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
+	XFS_STATS_INC(xs_blk_mapw);
+
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK);
+		if (error)
+			return error;
+	}
+
+	xfs_bmap_search_extents(ip, bno, XFS_DATA_FORK, &eof, &lastx, &got, &prev);
+	end = bno + len;
+	obno = bno;
+
+	while (bno < end && n < *nmap) {
+		if (eof || got.br_startoff > bno) {
+			error = xfs_bmapi_reserve_delalloc(ip, bno, len, &got,
+							   &prev, &lastx, eof);
+			if (error) {
+				if (n == 0) {
+					*nmap = 0;
+					return error;
+				}
+				break;
+			}
+		}
+
+		/* set up the extent map to return. */
+		xfs_bmapi_trim_map(mval, &got, &bno, len, obno, end, n, flags);
+		xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
+
+		/* If we're done, stop now. */
+		if (bno >= end || n >= *nmap)
+			break;
+
+		/* Else go on to the next record. */
+		prev = got;
+		if (++lastx < ifp->if_bytes / sizeof(xfs_bmbt_rec_t))
+			xfs_bmbt_get_all(xfs_iext_get_ext(ifp, lastx), &got);
+		else
+			eof = 1;
+	}
+
+	*nmap = n;
+	return 0;
+}
+
+
+static int
+xfs_bmapi_allocate(
+	struct xfs_bmalloca	*bma)
+{
+	struct xfs_mount	*mp = bma->ip->i_mount;
+	int			whichfork = (bma->flags & XFS_BMAPI_ATTRFORK) ?
+						XFS_ATTR_FORK : XFS_DATA_FORK;
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(bma->ip, whichfork);
+	int			tmp_logflags = 0;
+	int			error;
+
+	ASSERT(bma->length > 0);
+
+	/*
+	 * For the wasdelay case, we could also just allocate the stuff asked
+	 * for in this bmap call but that wouldn't be as good.
+	 */
+	if (bma->wasdel) {
+		bma->length = (xfs_extlen_t)bma->got.br_blockcount;
+		bma->offset = bma->got.br_startoff;
+		if (bma->idx != NULLEXTNUM && bma->idx) {
+			xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx - 1),
+					 &bma->prev);
+		}
+	} else {
+		bma->length = XFS_FILBLKS_MIN(bma->length, MAXEXTLEN);
+		if (!bma->eof)
+			bma->length = XFS_FILBLKS_MIN(bma->length,
+					bma->got.br_startoff - bma->offset);
+	}
+
+	/*
+	 * Indicate if this is the first user data in the file, or just any
+	 * user data.
+	 */
+	if (!(bma->flags & XFS_BMAPI_METADATA)) {
+		bma->userdata = (bma->offset == 0) ?
+			XFS_ALLOC_INITIAL_USER_DATA : XFS_ALLOC_USERDATA;
+	}
+
+	bma->minlen = (bma->flags & XFS_BMAPI_CONTIG) ? bma->length : 1;
+
+	/*
+	 * Only want to do the alignment at the eof if it is userdata and
+	 * allocation length is larger than a stripe unit.
+	 */
+	if (mp->m_dalign && bma->length >= mp->m_dalign &&
+	    !(bma->flags & XFS_BMAPI_METADATA) && whichfork == XFS_DATA_FORK) {
+		error = xfs_bmap_isaeof(bma, whichfork);
+		if (error)
+			return error;
+	}
+
+	error = xfs_bmap_alloc(bma);
+	if (error)
+		return error;
+
+	if (bma->flist->xbf_low)
+		bma->minleft = 0;
+	if (bma->cur)
+		bma->cur->bc_private.b.firstblock = *bma->firstblock;
+	if (bma->blkno == NULLFSBLOCK)
+		return 0;
+	if ((ifp->if_flags & XFS_IFBROOT) && !bma->cur) {
+		bma->cur = xfs_bmbt_init_cursor(mp, bma->tp, bma->ip, whichfork);
+		bma->cur->bc_private.b.firstblock = *bma->firstblock;
+		bma->cur->bc_private.b.flist = bma->flist;
+	}
+	/*
+	 * Bump the number of extents we've allocated
+	 * in this call.
+	 */
+	bma->nallocs++;
+
+	if (bma->cur)
+		bma->cur->bc_private.b.flags =
+			bma->wasdel ? XFS_BTCUR_BPRV_WASDEL : 0;
+
+	bma->got.br_startoff = bma->offset;
+	bma->got.br_startblock = bma->blkno;
+	bma->got.br_blockcount = bma->length;
+	bma->got.br_state = XFS_EXT_NORM;
+
+	/*
+	 * A wasdelay extent has been initialized, so shouldn't be flagged
+	 * as unwritten.
+	 */
+	if (!bma->wasdel && (bma->flags & XFS_BMAPI_PREALLOC) &&
+	    xfs_sb_version_hasextflgbit(&mp->m_sb))
+		bma->got.br_state = XFS_EXT_UNWRITTEN;
+
+	if (bma->wasdel)
+		error = xfs_bmap_add_extent_delay_real(bma);
+	else
+		error = xfs_bmap_add_extent_hole_real(bma, whichfork);
+
+	bma->logflags |= tmp_logflags;
+	if (error)
+		return error;
+
+	/*
+	 * Update our extent pointer, given that xfs_bmap_add_extent_delay_real
+	 * or xfs_bmap_add_extent_hole_real might have merged it into one of
+	 * the neighbouring ones.
+	 */
+	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx), &bma->got);
+
+	ASSERT(bma->got.br_startoff <= bma->offset);
+	ASSERT(bma->got.br_startoff + bma->got.br_blockcount >=
+	       bma->offset + bma->length);
+	ASSERT(bma->got.br_state == XFS_EXT_NORM ||
+	       bma->got.br_state == XFS_EXT_UNWRITTEN);
+	return 0;
+}
+
+STATIC int
+xfs_bmapi_convert_unwritten(
+	struct xfs_bmalloca	*bma,
+	struct xfs_bmbt_irec	*mval,
+	xfs_filblks_t		len,
+	int			flags)
+{
+	int			whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
+						XFS_ATTR_FORK : XFS_DATA_FORK;
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(bma->ip, whichfork);
+	int			tmp_logflags = 0;
+	int			error;
+
+	/* check if we need to do unwritten->real conversion */
+	if (mval->br_state == XFS_EXT_UNWRITTEN &&
+	    (flags & XFS_BMAPI_PREALLOC))
+		return 0;
+
+	/* check if we need to do real->unwritten conversion */
+	if (mval->br_state == XFS_EXT_NORM &&
+	    (flags & (XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT)) !=
+			(XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT))
+		return 0;
+
+	/*
+	 * Modify (by adding) the state flag, if writing.
+	 */
+	ASSERT(mval->br_blockcount <= len);
+	if ((ifp->if_flags & XFS_IFBROOT) && !bma->cur) {
+		bma->cur = xfs_bmbt_init_cursor(bma->ip->i_mount, bma->tp,
+					bma->ip, whichfork);
+		bma->cur->bc_private.b.firstblock = *bma->firstblock;
+		bma->cur->bc_private.b.flist = bma->flist;
+	}
+	mval->br_state = (mval->br_state == XFS_EXT_UNWRITTEN)
+				? XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
+
+	error = xfs_bmap_add_extent_unwritten_real(bma->tp, bma->ip, &bma->idx,
+			&bma->cur, mval, bma->firstblock, bma->flist,
+			&tmp_logflags);
+	bma->logflags |= tmp_logflags;
+	if (error)
+		return error;
+
+	/*
+	 * Update our extent pointer, given that
+	 * xfs_bmap_add_extent_unwritten_real might have merged it into one
+	 * of the neighbouring ones.
+	 */
+	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx), &bma->got);
+
+	/*
+	 * We may have combined previously unwritten space with written space,
+	 * so generate another request.
+	 */
+	if (mval->br_blockcount < len)
+		return -EAGAIN;
+	return 0;
+}
+
+/*
+ * Map file blocks to filesystem blocks, and allocate blocks or convert the
+ * extent state if necessary.  Details behaviour is controlled by the flags
+ * parameter.  Only allocates blocks from a single allocation group, to avoid
+ * locking problems.
+ *
+ * The returned value in "firstblock" from the first call in a transaction
+ * must be remembered and presented to subsequent calls in "firstblock".
+ * An upper bound for the number of blocks to be allocated is supplied to
+ * the first call in "total"; if no allocation group has that many free
+ * blocks then the call will fail (return NULLFSBLOCK in "firstblock").
+ */
+int
+xfs_bmapi_write(
+	struct xfs_trans	*tp,		/* transaction pointer */
+	struct xfs_inode	*ip,		/* incore inode */
+	xfs_fileoff_t		bno,		/* starting file offs. mapped */
+	xfs_filblks_t		len,		/* length to map in file */
+	int			flags,		/* XFS_BMAPI_... */
+	xfs_fsblock_t		*firstblock,	/* first allocated block
+						   controls a.g. for allocs */
+	xfs_extlen_t		total,		/* total blocks needed */
+	struct xfs_bmbt_irec	*mval,		/* output: map values */
+	int			*nmap,		/* i/o: mval size/count */
+	struct xfs_bmap_free	*flist)		/* i/o: list extents to free */
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_ifork	*ifp;
+	struct xfs_bmalloca	bma = { NULL };	/* args for xfs_bmap_alloc */
+	xfs_fileoff_t		end;		/* end of mapped file region */
+	int			eof;		/* after the end of extents */
+	int			error;		/* error return */
+	int			n;		/* current extent index */
+	xfs_fileoff_t		obno;		/* old block number (offset) */
+	int			whichfork;	/* data or attr fork */
+	char			inhole;		/* current location is hole in file */
+	char			wasdelay;	/* old extent was delayed */
+
+#ifdef DEBUG
+	xfs_fileoff_t		orig_bno;	/* original block number value */
+	int			orig_flags;	/* original flags arg value */
+	xfs_filblks_t		orig_len;	/* original value of len arg */
+	struct xfs_bmbt_irec	*orig_mval;	/* original value of mval */
+	int			orig_nmap;	/* original value of *nmap */
+
+	orig_bno = bno;
+	orig_len = len;
+	orig_flags = flags;
+	orig_mval = mval;
+	orig_nmap = *nmap;
+#endif
+	whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
+		XFS_ATTR_FORK : XFS_DATA_FORK;
+
+	ASSERT(*nmap >= 1);
+	ASSERT(*nmap <= XFS_BMAP_MAX_NMAP);
+	ASSERT(!(flags & XFS_BMAPI_IGSTATE));
+	ASSERT(tp != NULL);
+	ASSERT(len > 0);
+	ASSERT(XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL);
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	if (unlikely(XFS_TEST_ERROR(
+	    (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+	     XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE),
+	     mp, XFS_ERRTAG_BMAPIFORMAT, XFS_RANDOM_BMAPIFORMAT))) {
+		XFS_ERROR_REPORT("xfs_bmapi_write", XFS_ERRLEVEL_LOW, mp);
+		return -EFSCORRUPTED;
+	}
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+
+	XFS_STATS_INC(xs_blk_mapw);
+
+	if (*firstblock == NULLFSBLOCK) {
+		if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_BTREE)
+			bma.minleft = be16_to_cpu(ifp->if_broot->bb_level) + 1;
+		else
+			bma.minleft = 1;
+	} else {
+		bma.minleft = 0;
+	}
+
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		error = xfs_iread_extents(tp, ip, whichfork);
+		if (error)
+			goto error0;
+	}
+
+	xfs_bmap_search_extents(ip, bno, whichfork, &eof, &bma.idx, &bma.got,
+				&bma.prev);
+	n = 0;
+	end = bno + len;
+	obno = bno;
+
+	bma.tp = tp;
+	bma.ip = ip;
+	bma.total = total;
+	bma.userdata = 0;
+	bma.flist = flist;
+	bma.firstblock = firstblock;
+
+	while (bno < end && n < *nmap) {
+		inhole = eof || bma.got.br_startoff > bno;
+		wasdelay = !inhole && isnullstartblock(bma.got.br_startblock);
+
+		/*
+		 * First, deal with the hole before the allocated space
+		 * that we found, if any.
+		 */
+		if (inhole || wasdelay) {
+			bma.eof = eof;
+			bma.conv = !!(flags & XFS_BMAPI_CONVERT);
+			bma.wasdel = wasdelay;
+			bma.offset = bno;
+			bma.flags = flags;
+
+			/*
+			 * There's a 32/64 bit type mismatch between the
+			 * allocation length request (which can be 64 bits in
+			 * length) and the bma length request, which is
+			 * xfs_extlen_t and therefore 32 bits. Hence we have to
+			 * check for 32-bit overflows and handle them here.
+			 */
+			if (len > (xfs_filblks_t)MAXEXTLEN)
+				bma.length = MAXEXTLEN;
+			else
+				bma.length = len;
+
+			ASSERT(len > 0);
+			ASSERT(bma.length > 0);
+			error = xfs_bmapi_allocate(&bma);
+			if (error)
+				goto error0;
+			if (bma.blkno == NULLFSBLOCK)
+				break;
+		}
+
+		/* Deal with the allocated space we found.  */
+		xfs_bmapi_trim_map(mval, &bma.got, &bno, len, obno,
+							end, n, flags);
+
+		/* Execute unwritten extent conversion if necessary */
+		error = xfs_bmapi_convert_unwritten(&bma, mval, len, flags);
+		if (error == -EAGAIN)
+			continue;
+		if (error)
+			goto error0;
+
+		/* update the extent map to return */
+		xfs_bmapi_update_map(&mval, &bno, &len, obno, end, &n, flags);
+
+		/*
+		 * If we're done, stop now.  Stop when we've allocated
+		 * XFS_BMAP_MAX_NMAP extents no matter what.  Otherwise
+		 * the transaction may get too big.
+		 */
+		if (bno >= end || n >= *nmap || bma.nallocs >= *nmap)
+			break;
+
+		/* Else go on to the next record. */
+		bma.prev = bma.got;
+		if (++bma.idx < ifp->if_bytes / sizeof(xfs_bmbt_rec_t)) {
+			xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma.idx),
+					 &bma.got);
+		} else
+			eof = 1;
+	}
+	*nmap = n;
+
+	/*
+	 * Transform from btree to extents, give it cur.
+	 */
+	if (xfs_bmap_wants_extents(ip, whichfork)) {
+		int		tmp_logflags = 0;
+
+		ASSERT(bma.cur);
+		error = xfs_bmap_btree_to_extents(tp, ip, bma.cur,
+			&tmp_logflags, whichfork);
+		bma.logflags |= tmp_logflags;
+		if (error)
+			goto error0;
+	}
+
+	ASSERT(XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE ||
+	       XFS_IFORK_NEXTENTS(ip, whichfork) >
+		XFS_IFORK_MAXEXT(ip, whichfork));
+	error = 0;
+error0:
+	/*
+	 * Log everything.  Do this after conversion, there's no point in
+	 * logging the extent records if we've converted to btree format.
+	 */
+	if ((bma.logflags & xfs_ilog_fext(whichfork)) &&
+	    XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS)
+		bma.logflags &= ~xfs_ilog_fext(whichfork);
+	else if ((bma.logflags & xfs_ilog_fbroot(whichfork)) &&
+		 XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE)
+		bma.logflags &= ~xfs_ilog_fbroot(whichfork);
+	/*
+	 * Log whatever the flags say, even if error.  Otherwise we might miss
+	 * detecting a case where the data is changed, there's an error,
+	 * and it's not logged so we don't shutdown when we should.
+	 */
+	if (bma.logflags)
+		xfs_trans_log_inode(tp, ip, bma.logflags);
+
+	if (bma.cur) {
+		if (!error) {
+			ASSERT(*firstblock == NULLFSBLOCK ||
+			       XFS_FSB_TO_AGNO(mp, *firstblock) ==
+			       XFS_FSB_TO_AGNO(mp,
+				       bma.cur->bc_private.b.firstblock) ||
+			       (flist->xbf_low &&
+				XFS_FSB_TO_AGNO(mp, *firstblock) <
+				XFS_FSB_TO_AGNO(mp,
+					bma.cur->bc_private.b.firstblock)));
+			*firstblock = bma.cur->bc_private.b.firstblock;
+		}
+		xfs_btree_del_cursor(bma.cur,
+			error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+	}
+	if (!error)
+		xfs_bmap_validate_ret(orig_bno, orig_len, orig_flags, orig_mval,
+			orig_nmap, *nmap);
+	return error;
+}
+
+/*
+ * Called by xfs_bmapi to update file extent records and the btree
+ * after removing space (or undoing a delayed allocation).
+ */
+STATIC int				/* error */
+xfs_bmap_del_extent(
+	xfs_inode_t		*ip,	/* incore inode pointer */
+	xfs_trans_t		*tp,	/* current transaction pointer */
+	xfs_extnum_t		*idx,	/* extent number to update/delete */
+	xfs_bmap_free_t		*flist,	/* list of extents to be freed */
+	xfs_btree_cur_t		*cur,	/* if null, not a btree */
+	xfs_bmbt_irec_t		*del,	/* data to remove from extents */
+	int			*logflagsp, /* inode logging flags */
+	int			whichfork) /* data or attr fork */
+{
+	xfs_filblks_t		da_new;	/* new delay-alloc indirect blocks */
+	xfs_filblks_t		da_old;	/* old delay-alloc indirect blocks */
+	xfs_fsblock_t		del_endblock=0;	/* first block past del */
+	xfs_fileoff_t		del_endoff;	/* first offset past del */
+	int			delay;	/* current block is delayed allocated */
+	int			do_fx;	/* free extent at end of routine */
+	xfs_bmbt_rec_host_t	*ep;	/* current extent entry pointer */
+	int			error;	/* error return value */
+	int			flags;	/* inode logging flags */
+	xfs_bmbt_irec_t		got;	/* current extent entry */
+	xfs_fileoff_t		got_endoff;	/* first offset past got */
+	int			i;	/* temp state */
+	xfs_ifork_t		*ifp;	/* inode fork pointer */
+	xfs_mount_t		*mp;	/* mount structure */
+	xfs_filblks_t		nblks;	/* quota/sb block count */
+	xfs_bmbt_irec_t		new;	/* new record to be inserted */
+	/* REFERENCED */
+	uint			qfield;	/* quota field to update */
+	xfs_filblks_t		temp;	/* for indirect length calculations */
+	xfs_filblks_t		temp2;	/* for indirect length calculations */
+	int			state = 0;
+
+	XFS_STATS_INC(xs_del_exlist);
+
+	if (whichfork == XFS_ATTR_FORK)
+		state |= BMAP_ATTRFORK;
+
+	mp = ip->i_mount;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	ASSERT((*idx >= 0) && (*idx < ifp->if_bytes /
+		(uint)sizeof(xfs_bmbt_rec_t)));
+	ASSERT(del->br_blockcount > 0);
+	ep = xfs_iext_get_ext(ifp, *idx);
+	xfs_bmbt_get_all(ep, &got);
+	ASSERT(got.br_startoff <= del->br_startoff);
+	del_endoff = del->br_startoff + del->br_blockcount;
+	got_endoff = got.br_startoff + got.br_blockcount;
+	ASSERT(got_endoff >= del_endoff);
+	delay = isnullstartblock(got.br_startblock);
+	ASSERT(isnullstartblock(del->br_startblock) == delay);
+	flags = 0;
+	qfield = 0;
+	error = 0;
+	/*
+	 * If deleting a real allocation, must free up the disk space.
+	 */
+	if (!delay) {
+		flags = XFS_ILOG_CORE;
+		/*
+		 * Realtime allocation.  Free it and record di_nblocks update.
+		 */
+		if (whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip)) {
+			xfs_fsblock_t	bno;
+			xfs_filblks_t	len;
+
+			ASSERT(do_mod(del->br_blockcount,
+				      mp->m_sb.sb_rextsize) == 0);
+			ASSERT(do_mod(del->br_startblock,
+				      mp->m_sb.sb_rextsize) == 0);
+			bno = del->br_startblock;
+			len = del->br_blockcount;
+			do_div(bno, mp->m_sb.sb_rextsize);
+			do_div(len, mp->m_sb.sb_rextsize);
+			error = xfs_rtfree_extent(tp, bno, (xfs_extlen_t)len);
+			if (error)
+				goto done;
+			do_fx = 0;
+			nblks = len * mp->m_sb.sb_rextsize;
+			qfield = XFS_TRANS_DQ_RTBCOUNT;
+		}
+		/*
+		 * Ordinary allocation.
+		 */
+		else {
+			do_fx = 1;
+			nblks = del->br_blockcount;
+			qfield = XFS_TRANS_DQ_BCOUNT;
+		}
+		/*
+		 * Set up del_endblock and cur for later.
+		 */
+		del_endblock = del->br_startblock + del->br_blockcount;
+		if (cur) {
+			if ((error = xfs_bmbt_lookup_eq(cur, got.br_startoff,
+					got.br_startblock, got.br_blockcount,
+					&i)))
+				goto done;
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		}
+		da_old = da_new = 0;
+	} else {
+		da_old = startblockval(got.br_startblock);
+		da_new = 0;
+		nblks = 0;
+		do_fx = 0;
+	}
+	/*
+	 * Set flag value to use in switch statement.
+	 * Left-contig is 2, right-contig is 1.
+	 */
+	switch (((got.br_startoff == del->br_startoff) << 1) |
+		(got_endoff == del_endoff)) {
+	case 3:
+		/*
+		 * Matches the whole extent.  Delete the entry.
+		 */
+		xfs_iext_remove(ip, *idx, 1,
+				whichfork == XFS_ATTR_FORK ? BMAP_ATTRFORK : 0);
+		--*idx;
+		if (delay)
+			break;
+
+		XFS_IFORK_NEXT_SET(ip, whichfork,
+			XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
+		flags |= XFS_ILOG_CORE;
+		if (!cur) {
+			flags |= xfs_ilog_fext(whichfork);
+			break;
+		}
+		if ((error = xfs_btree_delete(cur, &i)))
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		break;
+
+	case 2:
+		/*
+		 * Deleting the first part of the extent.
+		 */
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_startoff(ep, del_endoff);
+		temp = got.br_blockcount - del->br_blockcount;
+		xfs_bmbt_set_blockcount(ep, temp);
+		if (delay) {
+			temp = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
+				da_old);
+			xfs_bmbt_set_startblock(ep, nullstartblock((int)temp));
+			trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+			da_new = temp;
+			break;
+		}
+		xfs_bmbt_set_startblock(ep, del_endblock);
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		if (!cur) {
+			flags |= xfs_ilog_fext(whichfork);
+			break;
+		}
+		if ((error = xfs_bmbt_update(cur, del_endoff, del_endblock,
+				got.br_blockcount - del->br_blockcount,
+				got.br_state)))
+			goto done;
+		break;
+
+	case 1:
+		/*
+		 * Deleting the last part of the extent.
+		 */
+		temp = got.br_blockcount - del->br_blockcount;
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep, temp);
+		if (delay) {
+			temp = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
+				da_old);
+			xfs_bmbt_set_startblock(ep, nullstartblock((int)temp));
+			trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+			da_new = temp;
+			break;
+		}
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		if (!cur) {
+			flags |= xfs_ilog_fext(whichfork);
+			break;
+		}
+		if ((error = xfs_bmbt_update(cur, got.br_startoff,
+				got.br_startblock,
+				got.br_blockcount - del->br_blockcount,
+				got.br_state)))
+			goto done;
+		break;
+
+	case 0:
+		/*
+		 * Deleting the middle of the extent.
+		 */
+		temp = del->br_startoff - got.br_startoff;
+		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
+		xfs_bmbt_set_blockcount(ep, temp);
+		new.br_startoff = del_endoff;
+		temp2 = got_endoff - del_endoff;
+		new.br_blockcount = temp2;
+		new.br_state = got.br_state;
+		if (!delay) {
+			new.br_startblock = del_endblock;
+			flags |= XFS_ILOG_CORE;
+			if (cur) {
+				if ((error = xfs_bmbt_update(cur,
+						got.br_startoff,
+						got.br_startblock, temp,
+						got.br_state)))
+					goto done;
+				if ((error = xfs_btree_increment(cur, 0, &i)))
+					goto done;
+				cur->bc_rec.b = new;
+				error = xfs_btree_insert(cur, &i);
+				if (error && error != -ENOSPC)
+					goto done;
+				/*
+				 * If get no-space back from btree insert,
+				 * it tried a split, and we have a zero
+				 * block reservation.
+				 * Fix up our state and return the error.
+				 */
+				if (error == -ENOSPC) {
+					/*
+					 * Reset the cursor, don't trust
+					 * it after any insert operation.
+					 */
+					if ((error = xfs_bmbt_lookup_eq(cur,
+							got.br_startoff,
+							got.br_startblock,
+							temp, &i)))
+						goto done;
+					XFS_WANT_CORRUPTED_GOTO(mp,
+								i == 1, done);
+					/*
+					 * Update the btree record back
+					 * to the original value.
+					 */
+					if ((error = xfs_bmbt_update(cur,
+							got.br_startoff,
+							got.br_startblock,
+							got.br_blockcount,
+							got.br_state)))
+						goto done;
+					/*
+					 * Reset the extent record back
+					 * to the original value.
+					 */
+					xfs_bmbt_set_blockcount(ep,
+						got.br_blockcount);
+					flags = 0;
+					error = -ENOSPC;
+					goto done;
+				}
+				XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+			} else
+				flags |= xfs_ilog_fext(whichfork);
+			XFS_IFORK_NEXT_SET(ip, whichfork,
+				XFS_IFORK_NEXTENTS(ip, whichfork) + 1);
+		} else {
+			ASSERT(whichfork == XFS_DATA_FORK);
+			temp = xfs_bmap_worst_indlen(ip, temp);
+			xfs_bmbt_set_startblock(ep, nullstartblock((int)temp));
+			temp2 = xfs_bmap_worst_indlen(ip, temp2);
+			new.br_startblock = nullstartblock((int)temp2);
+			da_new = temp + temp2;
+			while (da_new > da_old) {
+				if (temp) {
+					temp--;
+					da_new--;
+					xfs_bmbt_set_startblock(ep,
+						nullstartblock((int)temp));
+				}
+				if (da_new == da_old)
+					break;
+				if (temp2) {
+					temp2--;
+					da_new--;
+					new.br_startblock =
+						nullstartblock((int)temp2);
+				}
+			}
+		}
+		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		xfs_iext_insert(ip, *idx + 1, 1, &new, state);
+		++*idx;
+		break;
+	}
+	/*
+	 * If we need to, add to list of extents to delete.
+	 */
+	if (do_fx)
+		xfs_bmap_add_free(del->br_startblock, del->br_blockcount, flist,
+			mp);
+	/*
+	 * Adjust inode # blocks in the file.
+	 */
+	if (nblks)
+		ip->i_d.di_nblocks -= nblks;
+	/*
+	 * Adjust quota data.
+	 */
+	if (qfield)
+		xfs_trans_mod_dquot_byino(tp, ip, qfield, (long)-nblks);
+
+	/*
+	 * Account for change in delayed indirect blocks.
+	 * Nothing to do for disk quota accounting here.
+	 */
+	ASSERT(da_old >= da_new);
+	if (da_old > da_new)
+		xfs_mod_fdblocks(mp, (int64_t)(da_old - da_new), false);
+done:
+	*logflagsp = flags;
+	return error;
+}
+
+/*
+ * Unmap (remove) blocks from a file.
+ * If nexts is nonzero then the number of extents to remove is limited to
+ * that value.  If not all extents in the block range can be removed then
+ * *done is set.
+ */
+int						/* error */
+xfs_bunmapi(
+	xfs_trans_t		*tp,		/* transaction pointer */
+	struct xfs_inode	*ip,		/* incore inode */
+	xfs_fileoff_t		bno,		/* starting offset to unmap */
+	xfs_filblks_t		len,		/* length to unmap in file */
+	int			flags,		/* misc flags */
+	xfs_extnum_t		nexts,		/* number of extents max */
+	xfs_fsblock_t		*firstblock,	/* first allocated block
+						   controls a.g. for allocs */
+	xfs_bmap_free_t		*flist,		/* i/o: list extents to free */
+	int			*done)		/* set if not done yet */
+{
+	xfs_btree_cur_t		*cur;		/* bmap btree cursor */
+	xfs_bmbt_irec_t		del;		/* extent being deleted */
+	int			eof;		/* is deleting at eof */
+	xfs_bmbt_rec_host_t	*ep;		/* extent record pointer */
+	int			error;		/* error return value */
+	xfs_extnum_t		extno;		/* extent number in list */
+	xfs_bmbt_irec_t		got;		/* current extent record */
+	xfs_ifork_t		*ifp;		/* inode fork pointer */
+	int			isrt;		/* freeing in rt area */
+	xfs_extnum_t		lastx;		/* last extent index used */
+	int			logflags;	/* transaction logging flags */
+	xfs_extlen_t		mod;		/* rt extent offset */
+	xfs_mount_t		*mp;		/* mount structure */
+	xfs_extnum_t		nextents;	/* number of file extents */
+	xfs_bmbt_irec_t		prev;		/* previous extent record */
+	xfs_fileoff_t		start;		/* first file offset deleted */
+	int			tmp_logflags;	/* partial logging flags */
+	int			wasdel;		/* was a delayed alloc extent */
+	int			whichfork;	/* data or attribute fork */
+	xfs_fsblock_t		sum;
+
+	trace_xfs_bunmap(ip, bno, len, flags, _RET_IP_);
+
+	whichfork = (flags & XFS_BMAPI_ATTRFORK) ?
+		XFS_ATTR_FORK : XFS_DATA_FORK;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	if (unlikely(
+	    XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+	    XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE)) {
+		XFS_ERROR_REPORT("xfs_bunmapi", XFS_ERRLEVEL_LOW,
+				 ip->i_mount);
+		return -EFSCORRUPTED;
+	}
+	mp = ip->i_mount;
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+	ASSERT(len > 0);
+	ASSERT(nexts >= 0);
+
+	if (!(ifp->if_flags & XFS_IFEXTENTS) &&
+	    (error = xfs_iread_extents(tp, ip, whichfork)))
+		return error;
+	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	if (nextents == 0) {
+		*done = 1;
+		return 0;
+	}
+	XFS_STATS_INC(xs_blk_unmap);
+	isrt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(ip);
+	start = bno;
+	bno = start + len - 1;
+	ep = xfs_bmap_search_extents(ip, bno, whichfork, &eof, &lastx, &got,
+		&prev);
+
+	/*
+	 * Check to see if the given block number is past the end of the
+	 * file, back up to the last block if so...
+	 */
+	if (eof) {
+		ep = xfs_iext_get_ext(ifp, --lastx);
+		xfs_bmbt_get_all(ep, &got);
+		bno = got.br_startoff + got.br_blockcount - 1;
+	}
+	logflags = 0;
+	if (ifp->if_flags & XFS_IFBROOT) {
+		ASSERT(XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_BTREE);
+		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
+		cur->bc_private.b.firstblock = *firstblock;
+		cur->bc_private.b.flist = flist;
+		cur->bc_private.b.flags = 0;
+	} else
+		cur = NULL;
+
+	if (isrt) {
+		/*
+		 * Synchronize by locking the bitmap inode.
+		 */
+		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
+		xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
+	}
+
+	extno = 0;
+	while (bno != (xfs_fileoff_t)-1 && bno >= start && lastx >= 0 &&
+	       (nexts == 0 || extno < nexts)) {
+		/*
+		 * Is the found extent after a hole in which bno lives?
+		 * Just back up to the previous extent, if so.
+		 */
+		if (got.br_startoff > bno) {
+			if (--lastx < 0)
+				break;
+			ep = xfs_iext_get_ext(ifp, lastx);
+			xfs_bmbt_get_all(ep, &got);
+		}
+		/*
+		 * Is the last block of this extent before the range
+		 * we're supposed to delete?  If so, we're done.
+		 */
+		bno = XFS_FILEOFF_MIN(bno,
+			got.br_startoff + got.br_blockcount - 1);
+		if (bno < start)
+			break;
+		/*
+		 * Then deal with the (possibly delayed) allocated space
+		 * we found.
+		 */
+		ASSERT(ep != NULL);
+		del = got;
+		wasdel = isnullstartblock(del.br_startblock);
+		if (got.br_startoff < start) {
+			del.br_startoff = start;
+			del.br_blockcount -= start - got.br_startoff;
+			if (!wasdel)
+				del.br_startblock += start - got.br_startoff;
+		}
+		if (del.br_startoff + del.br_blockcount > bno + 1)
+			del.br_blockcount = bno + 1 - del.br_startoff;
+		sum = del.br_startblock + del.br_blockcount;
+		if (isrt &&
+		    (mod = do_mod(sum, mp->m_sb.sb_rextsize))) {
+			/*
+			 * Realtime extent not lined up at the end.
+			 * The extent could have been split into written
+			 * and unwritten pieces, or we could just be
+			 * unmapping part of it.  But we can't really
+			 * get rid of part of a realtime extent.
+			 */
+			if (del.br_state == XFS_EXT_UNWRITTEN ||
+			    !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
+				/*
+				 * This piece is unwritten, or we're not
+				 * using unwritten extents.  Skip over it.
+				 */
+				ASSERT(bno >= mod);
+				bno -= mod > del.br_blockcount ?
+					del.br_blockcount : mod;
+				if (bno < got.br_startoff) {
+					if (--lastx >= 0)
+						xfs_bmbt_get_all(xfs_iext_get_ext(
+							ifp, lastx), &got);
+				}
+				continue;
+			}
+			/*
+			 * It's written, turn it unwritten.
+			 * This is better than zeroing it.
+			 */
+			ASSERT(del.br_state == XFS_EXT_NORM);
+			ASSERT(xfs_trans_get_block_res(tp) > 0);
+			/*
+			 * If this spans a realtime extent boundary,
+			 * chop it back to the start of the one we end at.
+			 */
+			if (del.br_blockcount > mod) {
+				del.br_startoff += del.br_blockcount - mod;
+				del.br_startblock += del.br_blockcount - mod;
+				del.br_blockcount = mod;
+			}
+			del.br_state = XFS_EXT_UNWRITTEN;
+			error = xfs_bmap_add_extent_unwritten_real(tp, ip,
+					&lastx, &cur, &del, firstblock, flist,
+					&logflags);
+			if (error)
+				goto error0;
+			goto nodelete;
+		}
+		if (isrt && (mod = do_mod(del.br_startblock, mp->m_sb.sb_rextsize))) {
+			/*
+			 * Realtime extent is lined up at the end but not
+			 * at the front.  We'll get rid of full extents if
+			 * we can.
+			 */
+			mod = mp->m_sb.sb_rextsize - mod;
+			if (del.br_blockcount > mod) {
+				del.br_blockcount -= mod;
+				del.br_startoff += mod;
+				del.br_startblock += mod;
+			} else if ((del.br_startoff == start &&
+				    (del.br_state == XFS_EXT_UNWRITTEN ||
+				     xfs_trans_get_block_res(tp) == 0)) ||
+				   !xfs_sb_version_hasextflgbit(&mp->m_sb)) {
+				/*
+				 * Can't make it unwritten.  There isn't
+				 * a full extent here so just skip it.
+				 */
+				ASSERT(bno >= del.br_blockcount);
+				bno -= del.br_blockcount;
+				if (got.br_startoff > bno) {
+					if (--lastx >= 0) {
+						ep = xfs_iext_get_ext(ifp,
+								      lastx);
+						xfs_bmbt_get_all(ep, &got);
+					}
+				}
+				continue;
+			} else if (del.br_state == XFS_EXT_UNWRITTEN) {
+				/*
+				 * This one is already unwritten.
+				 * It must have a written left neighbor.
+				 * Unwrite the killed part of that one and
+				 * try again.
+				 */
+				ASSERT(lastx > 0);
+				xfs_bmbt_get_all(xfs_iext_get_ext(ifp,
+						lastx - 1), &prev);
+				ASSERT(prev.br_state == XFS_EXT_NORM);
+				ASSERT(!isnullstartblock(prev.br_startblock));
+				ASSERT(del.br_startblock ==
+				       prev.br_startblock + prev.br_blockcount);
+				if (prev.br_startoff < start) {
+					mod = start - prev.br_startoff;
+					prev.br_blockcount -= mod;
+					prev.br_startblock += mod;
+					prev.br_startoff = start;
+				}
+				prev.br_state = XFS_EXT_UNWRITTEN;
+				lastx--;
+				error = xfs_bmap_add_extent_unwritten_real(tp,
+						ip, &lastx, &cur, &prev,
+						firstblock, flist, &logflags);
+				if (error)
+					goto error0;
+				goto nodelete;
+			} else {
+				ASSERT(del.br_state == XFS_EXT_NORM);
+				del.br_state = XFS_EXT_UNWRITTEN;
+				error = xfs_bmap_add_extent_unwritten_real(tp,
+						ip, &lastx, &cur, &del,
+						firstblock, flist, &logflags);
+				if (error)
+					goto error0;
+				goto nodelete;
+			}
+		}
+		if (wasdel) {
+			ASSERT(startblockval(del.br_startblock) > 0);
+			/* Update realtime/data freespace, unreserve quota */
+			if (isrt) {
+				xfs_filblks_t rtexts;
+
+				rtexts = XFS_FSB_TO_B(mp, del.br_blockcount);
+				do_div(rtexts, mp->m_sb.sb_rextsize);
+				xfs_mod_frextents(mp, (int64_t)rtexts);
+				(void)xfs_trans_reserve_quota_nblks(NULL,
+					ip, -((long)del.br_blockcount), 0,
+					XFS_QMOPT_RES_RTBLKS);
+			} else {
+				xfs_mod_fdblocks(mp, (int64_t)del.br_blockcount,
+						 false);
+				(void)xfs_trans_reserve_quota_nblks(NULL,
+					ip, -((long)del.br_blockcount), 0,
+					XFS_QMOPT_RES_REGBLKS);
+			}
+			ip->i_delayed_blks -= del.br_blockcount;
+			if (cur)
+				cur->bc_private.b.flags |=
+					XFS_BTCUR_BPRV_WASDEL;
+		} else if (cur)
+			cur->bc_private.b.flags &= ~XFS_BTCUR_BPRV_WASDEL;
+		/*
+		 * If it's the case where the directory code is running
+		 * with no block reservation, and the deleted block is in
+		 * the middle of its extent, and the resulting insert
+		 * of an extent would cause transformation to btree format,
+		 * then reject it.  The calling code will then swap
+		 * blocks around instead.
+		 * We have to do this now, rather than waiting for the
+		 * conversion to btree format, since the transaction
+		 * will be dirty.
+		 */
+		if (!wasdel && xfs_trans_get_block_res(tp) == 0 &&
+		    XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_EXTENTS &&
+		    XFS_IFORK_NEXTENTS(ip, whichfork) >= /* Note the >= */
+			XFS_IFORK_MAXEXT(ip, whichfork) &&
+		    del.br_startoff > got.br_startoff &&
+		    del.br_startoff + del.br_blockcount <
+		    got.br_startoff + got.br_blockcount) {
+			error = -ENOSPC;
+			goto error0;
+		}
+		error = xfs_bmap_del_extent(ip, tp, &lastx, flist, cur, &del,
+				&tmp_logflags, whichfork);
+		logflags |= tmp_logflags;
+		if (error)
+			goto error0;
+		bno = del.br_startoff - 1;
+nodelete:
+		/*
+		 * If not done go on to the next (previous) record.
+		 */
+		if (bno != (xfs_fileoff_t)-1 && bno >= start) {
+			if (lastx >= 0) {
+				ep = xfs_iext_get_ext(ifp, lastx);
+				if (xfs_bmbt_get_startoff(ep) > bno) {
+					if (--lastx >= 0)
+						ep = xfs_iext_get_ext(ifp,
+								      lastx);
+				}
+				xfs_bmbt_get_all(ep, &got);
+			}
+			extno++;
+		}
+	}
+	*done = bno == (xfs_fileoff_t)-1 || bno < start || lastx < 0;
+
+	/*
+	 * Convert to a btree if necessary.
+	 */
+	if (xfs_bmap_needs_btree(ip, whichfork)) {
+		ASSERT(cur == NULL);
+		error = xfs_bmap_extents_to_btree(tp, ip, firstblock, flist,
+			&cur, 0, &tmp_logflags, whichfork);
+		logflags |= tmp_logflags;
+		if (error)
+			goto error0;
+	}
+	/*
+	 * transform from btree to extents, give it cur
+	 */
+	else if (xfs_bmap_wants_extents(ip, whichfork)) {
+		ASSERT(cur != NULL);
+		error = xfs_bmap_btree_to_extents(tp, ip, cur, &tmp_logflags,
+			whichfork);
+		logflags |= tmp_logflags;
+		if (error)
+			goto error0;
+	}
+	/*
+	 * transform from extents to local?
+	 */
+	error = 0;
+error0:
+	/*
+	 * Log everything.  Do this after conversion, there's no point in
+	 * logging the extent records if we've converted to btree format.
+	 */
+	if ((logflags & xfs_ilog_fext(whichfork)) &&
+	    XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS)
+		logflags &= ~xfs_ilog_fext(whichfork);
+	else if ((logflags & xfs_ilog_fbroot(whichfork)) &&
+		 XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE)
+		logflags &= ~xfs_ilog_fbroot(whichfork);
+	/*
+	 * Log inode even in the error case, if the transaction
+	 * is dirty we'll need to shut down the filesystem.
+	 */
+	if (logflags)
+		xfs_trans_log_inode(tp, ip, logflags);
+	if (cur) {
+		if (!error) {
+			*firstblock = cur->bc_private.b.firstblock;
+			cur->bc_private.b.allocated = 0;
+		}
+		xfs_btree_del_cursor(cur,
+			error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+	}
+	return error;
+}
+
+/*
+ * Determine whether an extent shift can be accomplished by a merge with the
+ * extent that precedes the target hole of the shift.
+ */
+STATIC bool
+xfs_bmse_can_merge(
+	struct xfs_bmbt_irec	*left,	/* preceding extent */
+	struct xfs_bmbt_irec	*got,	/* current extent to shift */
+	xfs_fileoff_t		shift)	/* shift fsb */
+{
+	xfs_fileoff_t		startoff;
+
+	startoff = got->br_startoff - shift;
+
+	/*
+	 * The extent, once shifted, must be adjacent in-file and on-disk with
+	 * the preceding extent.
+	 */
+	if ((left->br_startoff + left->br_blockcount != startoff) ||
+	    (left->br_startblock + left->br_blockcount != got->br_startblock) ||
+	    (left->br_state != got->br_state) ||
+	    (left->br_blockcount + got->br_blockcount > MAXEXTLEN))
+		return false;
+
+	return true;
+}
+
+/*
+ * A bmap extent shift adjusts the file offset of an extent to fill a preceding
+ * hole in the file. If an extent shift would result in the extent being fully
+ * adjacent to the extent that currently precedes the hole, we can merge with
+ * the preceding extent rather than do the shift.
+ *
+ * This function assumes the caller has verified a shift-by-merge is possible
+ * with the provided extents via xfs_bmse_can_merge().
+ */
+STATIC int
+xfs_bmse_merge(
+	struct xfs_inode		*ip,
+	int				whichfork,
+	xfs_fileoff_t			shift,		/* shift fsb */
+	int				current_ext,	/* idx of gotp */
+	struct xfs_bmbt_rec_host	*gotp,		/* extent to shift */
+	struct xfs_bmbt_rec_host	*leftp,		/* preceding extent */
+	struct xfs_btree_cur		*cur,
+	int				*logflags)	/* output */
+{
+	struct xfs_bmbt_irec		got;
+	struct xfs_bmbt_irec		left;
+	xfs_filblks_t			blockcount;
+	int				error, i;
+	struct xfs_mount		*mp = ip->i_mount;
+
+	xfs_bmbt_get_all(gotp, &got);
+	xfs_bmbt_get_all(leftp, &left);
+	blockcount = left.br_blockcount + got.br_blockcount;
+
+	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+	ASSERT(xfs_bmse_can_merge(&left, &got, shift));
+
+	/*
+	 * Merge the in-core extents. Note that the host record pointers and
+	 * current_ext index are invalid once the extent has been removed via
+	 * xfs_iext_remove().
+	 */
+	xfs_bmbt_set_blockcount(leftp, blockcount);
+	xfs_iext_remove(ip, current_ext, 1, 0);
+
+	/*
+	 * Update the on-disk extent count, the btree if necessary and log the
+	 * inode.
+	 */
+	XFS_IFORK_NEXT_SET(ip, whichfork,
+			   XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
+	*logflags |= XFS_ILOG_CORE;
+	if (!cur) {
+		*logflags |= XFS_ILOG_DEXT;
+		return 0;
+	}
+
+	/* lookup and remove the extent to merge */
+	error = xfs_bmbt_lookup_eq(cur, got.br_startoff, got.br_startblock,
+				   got.br_blockcount, &i);
+	if (error)
+		return error;
+	XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
+
+	error = xfs_btree_delete(cur, &i);
+	if (error)
+		return error;
+	XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
+
+	/* lookup and update size of the previous extent */
+	error = xfs_bmbt_lookup_eq(cur, left.br_startoff, left.br_startblock,
+				   left.br_blockcount, &i);
+	if (error)
+		return error;
+	XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
+
+	left.br_blockcount = blockcount;
+
+	return xfs_bmbt_update(cur, left.br_startoff, left.br_startblock,
+			       left.br_blockcount, left.br_state);
+}
+
+/*
+ * Shift a single extent.
+ */
+STATIC int
+xfs_bmse_shift_one(
+	struct xfs_inode		*ip,
+	int				whichfork,
+	xfs_fileoff_t			offset_shift_fsb,
+	int				*current_ext,
+	struct xfs_bmbt_rec_host	*gotp,
+	struct xfs_btree_cur		*cur,
+	int				*logflags,
+	enum shift_direction		direction)
+{
+	struct xfs_ifork		*ifp;
+	struct xfs_mount		*mp;
+	xfs_fileoff_t			startoff;
+	struct xfs_bmbt_rec_host	*adj_irecp;
+	struct xfs_bmbt_irec		got;
+	struct xfs_bmbt_irec		adj_irec;
+	int				error;
+	int				i;
+	int				total_extents;
+
+	mp = ip->i_mount;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
+
+	xfs_bmbt_get_all(gotp, &got);
+
+	/* delalloc extents should be prevented by caller */
+	XFS_WANT_CORRUPTED_RETURN(mp, !isnullstartblock(got.br_startblock));
+
+	if (direction == SHIFT_LEFT) {
+		startoff = got.br_startoff - offset_shift_fsb;
+
+		/*
+		 * Check for merge if we've got an extent to the left,
+		 * otherwise make sure there's enough room at the start
+		 * of the file for the shift.
+		 */
+		if (!*current_ext) {
+			if (got.br_startoff < offset_shift_fsb)
+				return -EINVAL;
+			goto update_current_ext;
+		}
+		/*
+		 * grab the left extent and check for a large
+		 * enough hole.
+		 */
+		adj_irecp = xfs_iext_get_ext(ifp, *current_ext - 1);
+		xfs_bmbt_get_all(adj_irecp, &adj_irec);
+
+		if (startoff <
+		    adj_irec.br_startoff + adj_irec.br_blockcount)
+			return -EINVAL;
+
+		/* check whether to merge the extent or shift it down */
+		if (xfs_bmse_can_merge(&adj_irec, &got,
+				       offset_shift_fsb)) {
+			return xfs_bmse_merge(ip, whichfork, offset_shift_fsb,
+					      *current_ext, gotp, adj_irecp,
+					      cur, logflags);
+		}
+	} else {
+		startoff = got.br_startoff + offset_shift_fsb;
+		/* nothing to move if this is the last extent */
+		if (*current_ext >= (total_extents - 1))
+			goto update_current_ext;
+		/*
+		 * If this is not the last extent in the file, make sure there
+		 * is enough room between current extent and next extent for
+		 * accommodating the shift.
+		 */
+		adj_irecp = xfs_iext_get_ext(ifp, *current_ext + 1);
+		xfs_bmbt_get_all(adj_irecp, &adj_irec);
+		if (startoff + got.br_blockcount > adj_irec.br_startoff)
+			return -EINVAL;
+		/*
+		 * Unlike a left shift (which involves a hole punch),
+		 * a right shift does not modify extent neighbors
+		 * in any way. We should never find mergeable extents
+		 * in this scenario. Check anyways and warn if we
+		 * encounter two extents that could be one.
+		 */
+		if (xfs_bmse_can_merge(&got, &adj_irec, offset_shift_fsb))
+			WARN_ON_ONCE(1);
+	}
+	/*
+	 * Increment the extent index for the next iteration, update the start
+	 * offset of the in-core extent and update the btree if applicable.
+	 */
+update_current_ext:
+	if (direction == SHIFT_LEFT)
+		(*current_ext)++;
+	else
+		(*current_ext)--;
+	xfs_bmbt_set_startoff(gotp, startoff);
+	*logflags |= XFS_ILOG_CORE;
+	if (!cur) {
+		*logflags |= XFS_ILOG_DEXT;
+		return 0;
+	}
+
+	error = xfs_bmbt_lookup_eq(cur, got.br_startoff, got.br_startblock,
+				   got.br_blockcount, &i);
+	if (error)
+		return error;
+	XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
+
+	got.br_startoff = startoff;
+	return xfs_bmbt_update(cur, got.br_startoff, got.br_startblock,
+			       got.br_blockcount, got.br_state);
+}
+
+/*
+ * Shift extent records to the left/right to cover/create a hole.
+ *
+ * The maximum number of extents to be shifted in a single operation is
+ * @num_exts. @stop_fsb specifies the file offset at which to stop shift and the
+ * file offset where we've left off is returned in @next_fsb. @offset_shift_fsb
+ * is the length by which each extent is shifted. If there is no hole to shift
+ * the extents into, this will be considered invalid operation and we abort
+ * immediately.
+ */
+int
+xfs_bmap_shift_extents(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	xfs_fileoff_t		*next_fsb,
+	xfs_fileoff_t		offset_shift_fsb,
+	int			*done,
+	xfs_fileoff_t		stop_fsb,
+	xfs_fsblock_t		*firstblock,
+	struct xfs_bmap_free	*flist,
+	enum shift_direction	direction,
+	int			num_exts)
+{
+	struct xfs_btree_cur		*cur = NULL;
+	struct xfs_bmbt_rec_host	*gotp;
+	struct xfs_bmbt_irec            got;
+	struct xfs_mount		*mp = ip->i_mount;
+	struct xfs_ifork		*ifp;
+	xfs_extnum_t			nexts = 0;
+	xfs_extnum_t			current_ext;
+	xfs_extnum_t			total_extents;
+	xfs_extnum_t			stop_extent;
+	int				error = 0;
+	int				whichfork = XFS_DATA_FORK;
+	int				logflags = 0;
+
+	if (unlikely(XFS_TEST_ERROR(
+	    (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+	     XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE),
+	     mp, XFS_ERRTAG_BMAPIFORMAT, XFS_RANDOM_BMAPIFORMAT))) {
+		XFS_ERROR_REPORT("xfs_bmap_shift_extents",
+				 XFS_ERRLEVEL_LOW, mp);
+		return -EFSCORRUPTED;
+	}
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
+	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+	ASSERT(direction == SHIFT_LEFT || direction == SHIFT_RIGHT);
+	ASSERT(*next_fsb != NULLFSBLOCK || direction == SHIFT_RIGHT);
+
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		/* Read in all the extents */
+		error = xfs_iread_extents(tp, ip, whichfork);
+		if (error)
+			return error;
+	}
+
+	if (ifp->if_flags & XFS_IFBROOT) {
+		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
+		cur->bc_private.b.firstblock = *firstblock;
+		cur->bc_private.b.flist = flist;
+		cur->bc_private.b.flags = 0;
+	}
+
+	/*
+	 * There may be delalloc extents in the data fork before the range we
+	 * are collapsing out, so we cannot use the count of real extents here.
+	 * Instead we have to calculate it from the incore fork.
+	 */
+	total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
+	if (total_extents == 0) {
+		*done = 1;
+		goto del_cursor;
+	}
+
+	/*
+	 * In case of first right shift, we need to initialize next_fsb
+	 */
+	if (*next_fsb == NULLFSBLOCK) {
+		gotp = xfs_iext_get_ext(ifp, total_extents - 1);
+		xfs_bmbt_get_all(gotp, &got);
+		*next_fsb = got.br_startoff;
+		if (stop_fsb > *next_fsb) {
+			*done = 1;
+			goto del_cursor;
+		}
+	}
+
+	/* Lookup the extent index at which we have to stop */
+	if (direction == SHIFT_RIGHT) {
+		gotp = xfs_iext_bno_to_ext(ifp, stop_fsb, &stop_extent);
+		/* Make stop_extent exclusive of shift range */
+		stop_extent--;
+	} else
+		stop_extent = total_extents;
+
+	/*
+	 * Look up the extent index for the fsb where we start shifting. We can
+	 * henceforth iterate with current_ext as extent list changes are locked
+	 * out via ilock.
+	 *
+	 * gotp can be null in 2 cases: 1) if there are no extents or 2)
+	 * *next_fsb lies in a hole beyond which there are no extents. Either
+	 * way, we are done.
+	 */
+	gotp = xfs_iext_bno_to_ext(ifp, *next_fsb, &current_ext);
+	if (!gotp) {
+		*done = 1;
+		goto del_cursor;
+	}
+
+	/* some sanity checking before we finally start shifting extents */
+	if ((direction == SHIFT_LEFT && current_ext >= stop_extent) ||
+	     (direction == SHIFT_RIGHT && current_ext <= stop_extent)) {
+		error = -EIO;
+		goto del_cursor;
+	}
+
+	while (nexts++ < num_exts) {
+		error = xfs_bmse_shift_one(ip, whichfork, offset_shift_fsb,
+					   &current_ext, gotp, cur, &logflags,
+					   direction);
+		if (error)
+			goto del_cursor;
+		/*
+		 * If there was an extent merge during the shift, the extent
+		 * count can change. Update the total and grade the next record.
+		 */
+		if (direction == SHIFT_LEFT) {
+			total_extents = ifp->if_bytes / sizeof(xfs_bmbt_rec_t);
+			stop_extent = total_extents;
+		}
+
+		if (current_ext == stop_extent) {
+			*done = 1;
+			*next_fsb = NULLFSBLOCK;
+			break;
+		}
+		gotp = xfs_iext_get_ext(ifp, current_ext);
+	}
+
+	if (!*done) {
+		xfs_bmbt_get_all(gotp, &got);
+		*next_fsb = got.br_startoff;
+	}
+
+del_cursor:
+	if (cur)
+		xfs_btree_del_cursor(cur,
+			error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+
+	if (logflags)
+		xfs_trans_log_inode(tp, ip, logflags);
+
+	return error;
+}
+
+/*
+ * Splits an extent into two extents at split_fsb block such that it is
+ * the first block of the current_ext. @current_ext is a target extent
+ * to be split. @split_fsb is a block where the extents is split.
+ * If split_fsb lies in a hole or the first block of extents, just return 0.
+ */
+STATIC int
+xfs_bmap_split_extent_at(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	xfs_fileoff_t		split_fsb,
+	xfs_fsblock_t		*firstfsb,
+	struct xfs_bmap_free	*free_list)
+{
+	int				whichfork = XFS_DATA_FORK;
+	struct xfs_btree_cur		*cur = NULL;
+	struct xfs_bmbt_rec_host	*gotp;
+	struct xfs_bmbt_irec		got;
+	struct xfs_bmbt_irec		new; /* split extent */
+	struct xfs_mount		*mp = ip->i_mount;
+	struct xfs_ifork		*ifp;
+	xfs_fsblock_t			gotblkcnt; /* new block count for got */
+	xfs_extnum_t			current_ext;
+	int				error = 0;
+	int				logflags = 0;
+	int				i = 0;
+
+	if (unlikely(XFS_TEST_ERROR(
+	    (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+	     XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE),
+	     mp, XFS_ERRTAG_BMAPIFORMAT, XFS_RANDOM_BMAPIFORMAT))) {
+		XFS_ERROR_REPORT("xfs_bmap_split_extent_at",
+				 XFS_ERRLEVEL_LOW, mp);
+		return -EFSCORRUPTED;
+	}
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		/* Read in all the extents */
+		error = xfs_iread_extents(tp, ip, whichfork);
+		if (error)
+			return error;
+	}
+
+	/*
+	 * gotp can be null in 2 cases: 1) if there are no extents
+	 * or 2) split_fsb lies in a hole beyond which there are
+	 * no extents. Either way, we are done.
+	 */
+	gotp = xfs_iext_bno_to_ext(ifp, split_fsb, &current_ext);
+	if (!gotp)
+		return 0;
+
+	xfs_bmbt_get_all(gotp, &got);
+
+	/*
+	 * Check split_fsb lies in a hole or the start boundary offset
+	 * of the extent.
+	 */
+	if (got.br_startoff >= split_fsb)
+		return 0;
+
+	gotblkcnt = split_fsb - got.br_startoff;
+	new.br_startoff = split_fsb;
+	new.br_startblock = got.br_startblock + gotblkcnt;
+	new.br_blockcount = got.br_blockcount - gotblkcnt;
+	new.br_state = got.br_state;
+
+	if (ifp->if_flags & XFS_IFBROOT) {
+		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
+		cur->bc_private.b.firstblock = *firstfsb;
+		cur->bc_private.b.flist = free_list;
+		cur->bc_private.b.flags = 0;
+		error = xfs_bmbt_lookup_eq(cur, got.br_startoff,
+				got.br_startblock,
+				got.br_blockcount,
+				&i);
+		if (error)
+			goto del_cursor;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, del_cursor);
+	}
+
+	xfs_bmbt_set_blockcount(gotp, gotblkcnt);
+	got.br_blockcount = gotblkcnt;
+
+	logflags = XFS_ILOG_CORE;
+	if (cur) {
+		error = xfs_bmbt_update(cur, got.br_startoff,
+				got.br_startblock,
+				got.br_blockcount,
+				got.br_state);
+		if (error)
+			goto del_cursor;
+	} else
+		logflags |= XFS_ILOG_DEXT;
+
+	/* Add new extent */
+	current_ext++;
+	xfs_iext_insert(ip, current_ext, 1, &new, 0);
+	XFS_IFORK_NEXT_SET(ip, whichfork,
+			   XFS_IFORK_NEXTENTS(ip, whichfork) + 1);
+
+	if (cur) {
+		error = xfs_bmbt_lookup_eq(cur, new.br_startoff,
+				new.br_startblock, new.br_blockcount,
+				&i);
+		if (error)
+			goto del_cursor;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 0, del_cursor);
+		cur->bc_rec.b.br_state = new.br_state;
+
+		error = xfs_btree_insert(cur, &i);
+		if (error)
+			goto del_cursor;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, del_cursor);
+	}
+
+	/*
+	 * Convert to a btree if necessary.
+	 */
+	if (xfs_bmap_needs_btree(ip, whichfork)) {
+		int tmp_logflags; /* partial log flag return val */
+
+		ASSERT(cur == NULL);
+		error = xfs_bmap_extents_to_btree(tp, ip, firstfsb, free_list,
+				&cur, 0, &tmp_logflags, whichfork);
+		logflags |= tmp_logflags;
+	}
+
+del_cursor:
+	if (cur) {
+		cur->bc_private.b.allocated = 0;
+		xfs_btree_del_cursor(cur,
+				error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+	}
+
+	if (logflags)
+		xfs_trans_log_inode(tp, ip, logflags);
+	return error;
+}
+
+int
+xfs_bmap_split_extent(
+	struct xfs_inode        *ip,
+	xfs_fileoff_t           split_fsb)
+{
+	struct xfs_mount        *mp = ip->i_mount;
+	struct xfs_trans        *tp;
+	struct xfs_bmap_free    free_list;
+	xfs_fsblock_t           firstfsb;
+	int                     committed;
+	int                     error;
+
+	tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT);
+	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write,
+			XFS_DIOSTRAT_SPACE_RES(mp, 0), 0);
+	if (error) {
+		xfs_trans_cancel(tp, 0);
+		return error;
+	}
+
+	xfs_ilock(ip, XFS_ILOCK_EXCL);
+	xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+
+	xfs_bmap_init(&free_list, &firstfsb);
+
+	error = xfs_bmap_split_extent_at(tp, ip, split_fsb,
+			&firstfsb, &free_list);
+	if (error)
+		goto out;
+
+	error = xfs_bmap_finish(&tp, &free_list, &committed);
+	if (error)
+		goto out;
+
+	return xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+
+
+out:
+	xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
+	return error;
+}