libxfs: move source files

Move all the source files that are shared with userspace into
libxfs/. This is done as one big chunk simpy to get it done
quickly

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 1050 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_dir2_data.c b/fs/xfs/libxfs/xfs_dir2_data.c
new file mode 100644
index 000000000000..8c2f6422648e
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_dir2_data.c
@@ -0,0 +1,1050 @@
+/*
+ * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
+ * Copyright (c) 2013 Red Hat, 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_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_mount.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_inode.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_error.h"
+#include "xfs_trans.h"
+#include "xfs_buf_item.h"
+#include "xfs_cksum.h"
+
+/*
+ * Check the consistency of the data block.
+ * The input can also be a block-format directory.
+ * Return 0 is the buffer is good, otherwise an error.
+ */
+int
+__xfs_dir3_data_check(
+	struct xfs_inode	*dp,		/* incore inode pointer */
+	struct xfs_buf		*bp)		/* data block's buffer */
+{
+	xfs_dir2_dataptr_t	addr;		/* addr for leaf lookup */
+	xfs_dir2_data_free_t	*bf;		/* bestfree table */
+	xfs_dir2_block_tail_t	*btp=NULL;	/* block tail */
+	int			count;		/* count of entries found */
+	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
+	xfs_dir2_data_entry_t	*dep;		/* data entry */
+	xfs_dir2_data_free_t	*dfp;		/* bestfree entry */
+	xfs_dir2_data_unused_t	*dup;		/* unused entry */
+	char			*endp;		/* end of useful data */
+	int			freeseen;	/* mask of bestfrees seen */
+	xfs_dahash_t		hash;		/* hash of current name */
+	int			i;		/* leaf index */
+	int			lastfree;	/* last entry was unused */
+	xfs_dir2_leaf_entry_t	*lep=NULL;	/* block leaf entries */
+	xfs_mount_t		*mp;		/* filesystem mount point */
+	char			*p;		/* current data position */
+	int			stale;		/* count of stale leaves */
+	struct xfs_name		name;
+	const struct xfs_dir_ops *ops;
+	struct xfs_da_geometry	*geo;
+
+	mp = bp->b_target->bt_mount;
+	geo = mp->m_dir_geo;
+
+	/*
+	 * We can be passed a null dp here from a verifier, so we need to go the
+	 * hard way to get them.
+	 */
+	ops = xfs_dir_get_ops(mp, dp);
+
+	hdr = bp->b_addr;
+	p = (char *)ops->data_entry_p(hdr);
+
+	switch (hdr->magic) {
+	case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
+	case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
+		btp = xfs_dir2_block_tail_p(geo, hdr);
+		lep = xfs_dir2_block_leaf_p(btp);
+		endp = (char *)lep;
+
+		/*
+		 * The number of leaf entries is limited by the size of the
+		 * block and the amount of space used by the data entries.
+		 * We don't know how much space is used by the data entries yet,
+		 * so just ensure that the count falls somewhere inside the
+		 * block right now.
+		 */
+		XFS_WANT_CORRUPTED_RETURN(be32_to_cpu(btp->count) <
+			((char *)btp - p) / sizeof(struct xfs_dir2_leaf_entry));
+		break;
+	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
+	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
+		endp = (char *)hdr + geo->blksize;
+		break;
+	default:
+		XFS_ERROR_REPORT("Bad Magic", XFS_ERRLEVEL_LOW, mp);
+		return EFSCORRUPTED;
+	}
+
+	/*
+	 * Account for zero bestfree entries.
+	 */
+	bf = ops->data_bestfree_p(hdr);
+	count = lastfree = freeseen = 0;
+	if (!bf[0].length) {
+		XFS_WANT_CORRUPTED_RETURN(!bf[0].offset);
+		freeseen |= 1 << 0;
+	}
+	if (!bf[1].length) {
+		XFS_WANT_CORRUPTED_RETURN(!bf[1].offset);
+		freeseen |= 1 << 1;
+	}
+	if (!bf[2].length) {
+		XFS_WANT_CORRUPTED_RETURN(!bf[2].offset);
+		freeseen |= 1 << 2;
+	}
+
+	XFS_WANT_CORRUPTED_RETURN(be16_to_cpu(bf[0].length) >=
+						be16_to_cpu(bf[1].length));
+	XFS_WANT_CORRUPTED_RETURN(be16_to_cpu(bf[1].length) >=
+						be16_to_cpu(bf[2].length));
+	/*
+	 * Loop over the data/unused entries.
+	 */
+	while (p < endp) {
+		dup = (xfs_dir2_data_unused_t *)p;
+		/*
+		 * If it's unused, look for the space in the bestfree table.
+		 * If we find it, account for that, else make sure it
+		 * doesn't need to be there.
+		 */
+		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
+			XFS_WANT_CORRUPTED_RETURN(lastfree == 0);
+			XFS_WANT_CORRUPTED_RETURN(
+				be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) ==
+					       (char *)dup - (char *)hdr);
+			dfp = xfs_dir2_data_freefind(hdr, bf, dup);
+			if (dfp) {
+				i = (int)(dfp - bf);
+				XFS_WANT_CORRUPTED_RETURN(
+					(freeseen & (1 << i)) == 0);
+				freeseen |= 1 << i;
+			} else {
+				XFS_WANT_CORRUPTED_RETURN(
+					be16_to_cpu(dup->length) <=
+						be16_to_cpu(bf[2].length));
+			}
+			p += be16_to_cpu(dup->length);
+			lastfree = 1;
+			continue;
+		}
+		/*
+		 * It's a real entry.  Validate the fields.
+		 * If this is a block directory then make sure it's
+		 * in the leaf section of the block.
+		 * The linear search is crude but this is DEBUG code.
+		 */
+		dep = (xfs_dir2_data_entry_t *)p;
+		XFS_WANT_CORRUPTED_RETURN(dep->namelen != 0);
+		XFS_WANT_CORRUPTED_RETURN(
+			!xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)));
+		XFS_WANT_CORRUPTED_RETURN(
+			be16_to_cpu(*ops->data_entry_tag_p(dep)) ==
+					       (char *)dep - (char *)hdr);
+		XFS_WANT_CORRUPTED_RETURN(
+				ops->data_get_ftype(dep) < XFS_DIR3_FT_MAX);
+		count++;
+		lastfree = 0;
+		if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+		    hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
+			addr = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
+						(xfs_dir2_data_aoff_t)
+						((char *)dep - (char *)hdr));
+			name.name = dep->name;
+			name.len = dep->namelen;
+			hash = mp->m_dirnameops->hashname(&name);
+			for (i = 0; i < be32_to_cpu(btp->count); i++) {
+				if (be32_to_cpu(lep[i].address) == addr &&
+				    be32_to_cpu(lep[i].hashval) == hash)
+					break;
+			}
+			XFS_WANT_CORRUPTED_RETURN(i < be32_to_cpu(btp->count));
+		}
+		p += ops->data_entsize(dep->namelen);
+	}
+	/*
+	 * Need to have seen all the entries and all the bestfree slots.
+	 */
+	XFS_WANT_CORRUPTED_RETURN(freeseen == 7);
+	if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	    hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
+		for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
+			if (lep[i].address ==
+			    cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
+				stale++;
+			if (i > 0)
+				XFS_WANT_CORRUPTED_RETURN(
+					be32_to_cpu(lep[i].hashval) >=
+						be32_to_cpu(lep[i - 1].hashval));
+		}
+		XFS_WANT_CORRUPTED_RETURN(count ==
+			be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
+		XFS_WANT_CORRUPTED_RETURN(stale == be32_to_cpu(btp->stale));
+	}
+	return 0;
+}
+
+static bool
+xfs_dir3_data_verify(
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_dir3_blk_hdr	*hdr3 = bp->b_addr;
+
+	if (xfs_sb_version_hascrc(&mp->m_sb)) {
+		if (hdr3->magic != cpu_to_be32(XFS_DIR3_DATA_MAGIC))
+			return false;
+		if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_uuid))
+			return false;
+		if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
+			return false;
+	} else {
+		if (hdr3->magic != cpu_to_be32(XFS_DIR2_DATA_MAGIC))
+			return false;
+	}
+	if (__xfs_dir3_data_check(NULL, bp))
+		return false;
+	return true;
+}
+
+/*
+ * Readahead of the first block of the directory when it is opened is completely
+ * oblivious to the format of the directory. Hence we can either get a block
+ * format buffer or a data format buffer on readahead.
+ */
+static void
+xfs_dir3_data_reada_verify(
+	struct xfs_buf		*bp)
+{
+	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
+
+	switch (hdr->magic) {
+	case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
+	case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
+		bp->b_ops = &xfs_dir3_block_buf_ops;
+		bp->b_ops->verify_read(bp);
+		return;
+	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
+	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
+		xfs_dir3_data_verify(bp);
+		return;
+	default:
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+		xfs_verifier_error(bp);
+		break;
+	}
+}
+
+static void
+xfs_dir3_data_read_verify(
+	struct xfs_buf	*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+
+	if (xfs_sb_version_hascrc(&mp->m_sb) &&
+	     !xfs_buf_verify_cksum(bp, XFS_DIR3_DATA_CRC_OFF))
+		 xfs_buf_ioerror(bp, EFSBADCRC);
+	else if (!xfs_dir3_data_verify(bp))
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+
+	if (bp->b_error)
+		xfs_verifier_error(bp);
+}
+
+static void
+xfs_dir3_data_write_verify(
+	struct xfs_buf	*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_buf_log_item	*bip = bp->b_fspriv;
+	struct xfs_dir3_blk_hdr	*hdr3 = bp->b_addr;
+
+	if (!xfs_dir3_data_verify(bp)) {
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+		xfs_verifier_error(bp);
+		return;
+	}
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return;
+
+	if (bip)
+		hdr3->lsn = cpu_to_be64(bip->bli_item.li_lsn);
+
+	xfs_buf_update_cksum(bp, XFS_DIR3_DATA_CRC_OFF);
+}
+
+const struct xfs_buf_ops xfs_dir3_data_buf_ops = {
+	.verify_read = xfs_dir3_data_read_verify,
+	.verify_write = xfs_dir3_data_write_verify,
+};
+
+static const struct xfs_buf_ops xfs_dir3_data_reada_buf_ops = {
+	.verify_read = xfs_dir3_data_reada_verify,
+	.verify_write = xfs_dir3_data_write_verify,
+};
+
+
+int
+xfs_dir3_data_read(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*dp,
+	xfs_dablk_t		bno,
+	xfs_daddr_t		mapped_bno,
+	struct xfs_buf		**bpp)
+{
+	int			err;
+
+	err = xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp,
+				XFS_DATA_FORK, &xfs_dir3_data_buf_ops);
+	if (!err && tp)
+		xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
+	return err;
+}
+
+int
+xfs_dir3_data_readahead(
+	struct xfs_inode	*dp,
+	xfs_dablk_t		bno,
+	xfs_daddr_t		mapped_bno)
+{
+	return xfs_da_reada_buf(dp, bno, mapped_bno,
+				XFS_DATA_FORK, &xfs_dir3_data_reada_buf_ops);
+}
+
+/*
+ * Given a data block and an unused entry from that block,
+ * return the bestfree entry if any that corresponds to it.
+ */
+xfs_dir2_data_free_t *
+xfs_dir2_data_freefind(
+	struct xfs_dir2_data_hdr *hdr,		/* data block header */
+	struct xfs_dir2_data_free *bf,		/* bestfree table pointer */
+	struct xfs_dir2_data_unused *dup)	/* unused space */
+{
+	xfs_dir2_data_free_t	*dfp;		/* bestfree entry */
+	xfs_dir2_data_aoff_t	off;		/* offset value needed */
+#ifdef DEBUG
+	int			matched;	/* matched the value */
+	int			seenzero;	/* saw a 0 bestfree entry */
+#endif
+
+	off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)hdr);
+
+#ifdef DEBUG
+	/*
+	 * Validate some consistency in the bestfree table.
+	 * Check order, non-overlapping entries, and if we find the
+	 * one we're looking for it has to be exact.
+	 */
+	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
+	for (dfp = &bf[0], seenzero = matched = 0;
+	     dfp < &bf[XFS_DIR2_DATA_FD_COUNT];
+	     dfp++) {
+		if (!dfp->offset) {
+			ASSERT(!dfp->length);
+			seenzero = 1;
+			continue;
+		}
+		ASSERT(seenzero == 0);
+		if (be16_to_cpu(dfp->offset) == off) {
+			matched = 1;
+			ASSERT(dfp->length == dup->length);
+		} else if (off < be16_to_cpu(dfp->offset))
+			ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
+		else
+			ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
+		ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
+		if (dfp > &bf[0])
+			ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
+	}
+#endif
+	/*
+	 * If this is smaller than the smallest bestfree entry,
+	 * it can't be there since they're sorted.
+	 */
+	if (be16_to_cpu(dup->length) <
+	    be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
+		return NULL;
+	/*
+	 * Look at the three bestfree entries for our guy.
+	 */
+	for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
+		if (!dfp->offset)
+			return NULL;
+		if (be16_to_cpu(dfp->offset) == off)
+			return dfp;
+	}
+	/*
+	 * Didn't find it.  This only happens if there are duplicate lengths.
+	 */
+	return NULL;
+}
+
+/*
+ * Insert an unused-space entry into the bestfree table.
+ */
+xfs_dir2_data_free_t *				/* entry inserted */
+xfs_dir2_data_freeinsert(
+	struct xfs_dir2_data_hdr *hdr,		/* data block pointer */
+	struct xfs_dir2_data_free *dfp,		/* bestfree table pointer */
+	struct xfs_dir2_data_unused *dup,	/* unused space */
+	int			*loghead)	/* log the data header (out) */
+{
+	xfs_dir2_data_free_t	new;		/* new bestfree entry */
+
+	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
+
+	new.length = dup->length;
+	new.offset = cpu_to_be16((char *)dup - (char *)hdr);
+
+	/*
+	 * Insert at position 0, 1, or 2; or not at all.
+	 */
+	if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
+		dfp[2] = dfp[1];
+		dfp[1] = dfp[0];
+		dfp[0] = new;
+		*loghead = 1;
+		return &dfp[0];
+	}
+	if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
+		dfp[2] = dfp[1];
+		dfp[1] = new;
+		*loghead = 1;
+		return &dfp[1];
+	}
+	if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
+		dfp[2] = new;
+		*loghead = 1;
+		return &dfp[2];
+	}
+	return NULL;
+}
+
+/*
+ * Remove a bestfree entry from the table.
+ */
+STATIC void
+xfs_dir2_data_freeremove(
+	struct xfs_dir2_data_hdr *hdr,		/* data block header */
+	struct xfs_dir2_data_free *bf,		/* bestfree table pointer */
+	struct xfs_dir2_data_free *dfp,		/* bestfree entry pointer */
+	int			*loghead)	/* out: log data header */
+{
+
+	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
+
+	/*
+	 * It's the first entry, slide the next 2 up.
+	 */
+	if (dfp == &bf[0]) {
+		bf[0] = bf[1];
+		bf[1] = bf[2];
+	}
+	/*
+	 * It's the second entry, slide the 3rd entry up.
+	 */
+	else if (dfp == &bf[1])
+		bf[1] = bf[2];
+	/*
+	 * Must be the last entry.
+	 */
+	else
+		ASSERT(dfp == &bf[2]);
+	/*
+	 * Clear the 3rd entry, must be zero now.
+	 */
+	bf[2].length = 0;
+	bf[2].offset = 0;
+	*loghead = 1;
+}
+
+/*
+ * Given a data block, reconstruct its bestfree map.
+ */
+void
+xfs_dir2_data_freescan(
+	struct xfs_inode	*dp,
+	struct xfs_dir2_data_hdr *hdr,
+	int			*loghead)
+{
+	xfs_dir2_block_tail_t	*btp;		/* block tail */
+	xfs_dir2_data_entry_t	*dep;		/* active data entry */
+	xfs_dir2_data_unused_t	*dup;		/* unused data entry */
+	struct xfs_dir2_data_free *bf;
+	char			*endp;		/* end of block's data */
+	char			*p;		/* current entry pointer */
+	struct xfs_da_geometry	*geo = dp->i_mount->m_dir_geo;
+
+	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
+
+	/*
+	 * Start by clearing the table.
+	 */
+	bf = dp->d_ops->data_bestfree_p(hdr);
+	memset(bf, 0, sizeof(*bf) * XFS_DIR2_DATA_FD_COUNT);
+	*loghead = 1;
+	/*
+	 * Set up pointers.
+	 */
+	p = (char *)dp->d_ops->data_entry_p(hdr);
+	if (hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	    hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC)) {
+		btp = xfs_dir2_block_tail_p(geo, hdr);
+		endp = (char *)xfs_dir2_block_leaf_p(btp);
+	} else
+		endp = (char *)hdr + geo->blksize;
+	/*
+	 * Loop over the block's entries.
+	 */
+	while (p < endp) {
+		dup = (xfs_dir2_data_unused_t *)p;
+		/*
+		 * If it's a free entry, insert it.
+		 */
+		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
+			ASSERT((char *)dup - (char *)hdr ==
+			       be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
+			xfs_dir2_data_freeinsert(hdr, bf, dup, loghead);
+			p += be16_to_cpu(dup->length);
+		}
+		/*
+		 * For active entries, check their tags and skip them.
+		 */
+		else {
+			dep = (xfs_dir2_data_entry_t *)p;
+			ASSERT((char *)dep - (char *)hdr ==
+			       be16_to_cpu(*dp->d_ops->data_entry_tag_p(dep)));
+			p += dp->d_ops->data_entsize(dep->namelen);
+		}
+	}
+}
+
+/*
+ * Initialize a data block at the given block number in the directory.
+ * Give back the buffer for the created block.
+ */
+int						/* error */
+xfs_dir3_data_init(
+	xfs_da_args_t		*args,		/* directory operation args */
+	xfs_dir2_db_t		blkno,		/* logical dir block number */
+	struct xfs_buf		**bpp)		/* output block buffer */
+{
+	struct xfs_buf		*bp;		/* block buffer */
+	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
+	xfs_inode_t		*dp;		/* incore directory inode */
+	xfs_dir2_data_unused_t	*dup;		/* unused entry pointer */
+	struct xfs_dir2_data_free *bf;
+	int			error;		/* error return value */
+	int			i;		/* bestfree index */
+	xfs_mount_t		*mp;		/* filesystem mount point */
+	xfs_trans_t		*tp;		/* transaction pointer */
+	int                     t;              /* temp */
+
+	dp = args->dp;
+	mp = dp->i_mount;
+	tp = args->trans;
+	/*
+	 * Get the buffer set up for the block.
+	 */
+	error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(args->geo, blkno),
+			       -1, &bp, XFS_DATA_FORK);
+	if (error)
+		return error;
+	bp->b_ops = &xfs_dir3_data_buf_ops;
+	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_DATA_BUF);
+
+	/*
+	 * Initialize the header.
+	 */
+	hdr = bp->b_addr;
+	if (xfs_sb_version_hascrc(&mp->m_sb)) {
+		struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr;
+
+		memset(hdr3, 0, sizeof(*hdr3));
+		hdr3->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC);
+		hdr3->blkno = cpu_to_be64(bp->b_bn);
+		hdr3->owner = cpu_to_be64(dp->i_ino);
+		uuid_copy(&hdr3->uuid, &mp->m_sb.sb_uuid);
+
+	} else
+		hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
+
+	bf = dp->d_ops->data_bestfree_p(hdr);
+	bf[0].offset = cpu_to_be16(dp->d_ops->data_entry_offset);
+	for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
+		bf[i].length = 0;
+		bf[i].offset = 0;
+	}
+
+	/*
+	 * Set up an unused entry for the block's body.
+	 */
+	dup = dp->d_ops->data_unused_p(hdr);
+	dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
+
+	t = args->geo->blksize - (uint)dp->d_ops->data_entry_offset;
+	bf[0].length = cpu_to_be16(t);
+	dup->length = cpu_to_be16(t);
+	*xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
+	/*
+	 * Log it and return it.
+	 */
+	xfs_dir2_data_log_header(args, bp);
+	xfs_dir2_data_log_unused(args, bp, dup);
+	*bpp = bp;
+	return 0;
+}
+
+/*
+ * Log an active data entry from the block.
+ */
+void
+xfs_dir2_data_log_entry(
+	struct xfs_da_args	*args,
+	struct xfs_buf		*bp,
+	xfs_dir2_data_entry_t	*dep)		/* data entry pointer */
+{
+	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
+
+	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
+
+	xfs_trans_log_buf(args->trans, bp, (uint)((char *)dep - (char *)hdr),
+		(uint)((char *)(args->dp->d_ops->data_entry_tag_p(dep) + 1) -
+		       (char *)hdr - 1));
+}
+
+/*
+ * Log a data block header.
+ */
+void
+xfs_dir2_data_log_header(
+	struct xfs_da_args	*args,
+	struct xfs_buf		*bp)
+{
+#ifdef DEBUG
+	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
+
+	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
+#endif
+
+	xfs_trans_log_buf(args->trans, bp, 0,
+			  args->dp->d_ops->data_entry_offset - 1);
+}
+
+/*
+ * Log a data unused entry.
+ */
+void
+xfs_dir2_data_log_unused(
+	struct xfs_da_args	*args,
+	struct xfs_buf		*bp,
+	xfs_dir2_data_unused_t	*dup)		/* data unused pointer */
+{
+	xfs_dir2_data_hdr_t	*hdr = bp->b_addr;
+
+	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
+
+	/*
+	 * Log the first part of the unused entry.
+	 */
+	xfs_trans_log_buf(args->trans, bp, (uint)((char *)dup - (char *)hdr),
+		(uint)((char *)&dup->length + sizeof(dup->length) -
+		       1 - (char *)hdr));
+	/*
+	 * Log the end (tag) of the unused entry.
+	 */
+	xfs_trans_log_buf(args->trans, bp,
+		(uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr),
+		(uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)hdr +
+		       sizeof(xfs_dir2_data_off_t) - 1));
+}
+
+/*
+ * Make a byte range in the data block unused.
+ * Its current contents are unimportant.
+ */
+void
+xfs_dir2_data_make_free(
+	struct xfs_da_args	*args,
+	struct xfs_buf		*bp,
+	xfs_dir2_data_aoff_t	offset,		/* starting byte offset */
+	xfs_dir2_data_aoff_t	len,		/* length in bytes */
+	int			*needlogp,	/* out: log header */
+	int			*needscanp)	/* out: regen bestfree */
+{
+	xfs_dir2_data_hdr_t	*hdr;		/* data block pointer */
+	xfs_dir2_data_free_t	*dfp;		/* bestfree pointer */
+	char			*endptr;	/* end of data area */
+	int			needscan;	/* need to regen bestfree */
+	xfs_dir2_data_unused_t	*newdup;	/* new unused entry */
+	xfs_dir2_data_unused_t	*postdup;	/* unused entry after us */
+	xfs_dir2_data_unused_t	*prevdup;	/* unused entry before us */
+	struct xfs_dir2_data_free *bf;
+
+	hdr = bp->b_addr;
+
+	/*
+	 * Figure out where the end of the data area is.
+	 */
+	if (hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
+	    hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC))
+		endptr = (char *)hdr + args->geo->blksize;
+	else {
+		xfs_dir2_block_tail_t	*btp;	/* block tail */
+
+		ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+			hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
+		btp = xfs_dir2_block_tail_p(args->geo, hdr);
+		endptr = (char *)xfs_dir2_block_leaf_p(btp);
+	}
+	/*
+	 * If this isn't the start of the block, then back up to
+	 * the previous entry and see if it's free.
+	 */
+	if (offset > args->dp->d_ops->data_entry_offset) {
+		__be16			*tagp;	/* tag just before us */
+
+		tagp = (__be16 *)((char *)hdr + offset) - 1;
+		prevdup = (xfs_dir2_data_unused_t *)((char *)hdr + be16_to_cpu(*tagp));
+		if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
+			prevdup = NULL;
+	} else
+		prevdup = NULL;
+	/*
+	 * If this isn't the end of the block, see if the entry after
+	 * us is free.
+	 */
+	if ((char *)hdr + offset + len < endptr) {
+		postdup =
+			(xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
+		if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
+			postdup = NULL;
+	} else
+		postdup = NULL;
+	ASSERT(*needscanp == 0);
+	needscan = 0;
+	/*
+	 * Previous and following entries are both free,
+	 * merge everything into a single free entry.
+	 */
+	bf = args->dp->d_ops->data_bestfree_p(hdr);
+	if (prevdup && postdup) {
+		xfs_dir2_data_free_t	*dfp2;	/* another bestfree pointer */
+
+		/*
+		 * See if prevdup and/or postdup are in bestfree table.
+		 */
+		dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
+		dfp2 = xfs_dir2_data_freefind(hdr, bf, postdup);
+		/*
+		 * We need a rescan unless there are exactly 2 free entries
+		 * namely our two.  Then we know what's happening, otherwise
+		 * since the third bestfree is there, there might be more
+		 * entries.
+		 */
+		needscan = (bf[2].length != 0);
+		/*
+		 * Fix up the new big freespace.
+		 */
+		be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
+		*xfs_dir2_data_unused_tag_p(prevdup) =
+			cpu_to_be16((char *)prevdup - (char *)hdr);
+		xfs_dir2_data_log_unused(args, bp, prevdup);
+		if (!needscan) {
+			/*
+			 * Has to be the case that entries 0 and 1 are
+			 * dfp and dfp2 (don't know which is which), and
+			 * entry 2 is empty.
+			 * Remove entry 1 first then entry 0.
+			 */
+			ASSERT(dfp && dfp2);
+			if (dfp == &bf[1]) {
+				dfp = &bf[0];
+				ASSERT(dfp2 == dfp);
+				dfp2 = &bf[1];
+			}
+			xfs_dir2_data_freeremove(hdr, bf, dfp2, needlogp);
+			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
+			/*
+			 * Now insert the new entry.
+			 */
+			dfp = xfs_dir2_data_freeinsert(hdr, bf, prevdup,
+						       needlogp);
+			ASSERT(dfp == &bf[0]);
+			ASSERT(dfp->length == prevdup->length);
+			ASSERT(!dfp[1].length);
+			ASSERT(!dfp[2].length);
+		}
+	}
+	/*
+	 * The entry before us is free, merge with it.
+	 */
+	else if (prevdup) {
+		dfp = xfs_dir2_data_freefind(hdr, bf, prevdup);
+		be16_add_cpu(&prevdup->length, len);
+		*xfs_dir2_data_unused_tag_p(prevdup) =
+			cpu_to_be16((char *)prevdup - (char *)hdr);
+		xfs_dir2_data_log_unused(args, bp, prevdup);
+		/*
+		 * If the previous entry was in the table, the new entry
+		 * is longer, so it will be in the table too.  Remove
+		 * the old one and add the new one.
+		 */
+		if (dfp) {
+			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
+			xfs_dir2_data_freeinsert(hdr, bf, prevdup, needlogp);
+		}
+		/*
+		 * Otherwise we need a scan if the new entry is big enough.
+		 */
+		else {
+			needscan = be16_to_cpu(prevdup->length) >
+				   be16_to_cpu(bf[2].length);
+		}
+	}
+	/*
+	 * The following entry is free, merge with it.
+	 */
+	else if (postdup) {
+		dfp = xfs_dir2_data_freefind(hdr, bf, postdup);
+		newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
+		newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
+		newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
+		*xfs_dir2_data_unused_tag_p(newdup) =
+			cpu_to_be16((char *)newdup - (char *)hdr);
+		xfs_dir2_data_log_unused(args, bp, newdup);
+		/*
+		 * If the following entry was in the table, the new entry
+		 * is longer, so it will be in the table too.  Remove
+		 * the old one and add the new one.
+		 */
+		if (dfp) {
+			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
+			xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
+		}
+		/*
+		 * Otherwise we need a scan if the new entry is big enough.
+		 */
+		else {
+			needscan = be16_to_cpu(newdup->length) >
+				   be16_to_cpu(bf[2].length);
+		}
+	}
+	/*
+	 * Neither neighbor is free.  Make a new entry.
+	 */
+	else {
+		newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset);
+		newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
+		newdup->length = cpu_to_be16(len);
+		*xfs_dir2_data_unused_tag_p(newdup) =
+			cpu_to_be16((char *)newdup - (char *)hdr);
+		xfs_dir2_data_log_unused(args, bp, newdup);
+		xfs_dir2_data_freeinsert(hdr, bf, newdup, needlogp);
+	}
+	*needscanp = needscan;
+}
+
+/*
+ * Take a byte range out of an existing unused space and make it un-free.
+ */
+void
+xfs_dir2_data_use_free(
+	struct xfs_da_args	*args,
+	struct xfs_buf		*bp,
+	xfs_dir2_data_unused_t	*dup,		/* unused entry */
+	xfs_dir2_data_aoff_t	offset,		/* starting offset to use */
+	xfs_dir2_data_aoff_t	len,		/* length to use */
+	int			*needlogp,	/* out: need to log header */
+	int			*needscanp)	/* out: need regen bestfree */
+{
+	xfs_dir2_data_hdr_t	*hdr;		/* data block header */
+	xfs_dir2_data_free_t	*dfp;		/* bestfree pointer */
+	int			matchback;	/* matches end of freespace */
+	int			matchfront;	/* matches start of freespace */
+	int			needscan;	/* need to regen bestfree */
+	xfs_dir2_data_unused_t	*newdup;	/* new unused entry */
+	xfs_dir2_data_unused_t	*newdup2;	/* another new unused entry */
+	int			oldlen;		/* old unused entry's length */
+	struct xfs_dir2_data_free *bf;
+
+	hdr = bp->b_addr;
+	ASSERT(hdr->magic == cpu_to_be32(XFS_DIR2_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_DATA_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR2_BLOCK_MAGIC) ||
+	       hdr->magic == cpu_to_be32(XFS_DIR3_BLOCK_MAGIC));
+	ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
+	ASSERT(offset >= (char *)dup - (char *)hdr);
+	ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)hdr);
+	ASSERT((char *)dup - (char *)hdr == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
+	/*
+	 * Look up the entry in the bestfree table.
+	 */
+	oldlen = be16_to_cpu(dup->length);
+	bf = args->dp->d_ops->data_bestfree_p(hdr);
+	dfp = xfs_dir2_data_freefind(hdr, bf, dup);
+	ASSERT(dfp || oldlen <= be16_to_cpu(bf[2].length));
+	/*
+	 * Check for alignment with front and back of the entry.
+	 */
+	matchfront = (char *)dup - (char *)hdr == offset;
+	matchback = (char *)dup + oldlen - (char *)hdr == offset + len;
+	ASSERT(*needscanp == 0);
+	needscan = 0;
+	/*
+	 * If we matched it exactly we just need to get rid of it from
+	 * the bestfree table.
+	 */
+	if (matchfront && matchback) {
+		if (dfp) {
+			needscan = (bf[2].offset != 0);
+			if (!needscan)
+				xfs_dir2_data_freeremove(hdr, bf, dfp,
+							 needlogp);
+		}
+	}
+	/*
+	 * We match the first part of the entry.
+	 * Make a new entry with the remaining freespace.
+	 */
+	else if (matchfront) {
+		newdup = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
+		newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
+		newdup->length = cpu_to_be16(oldlen - len);
+		*xfs_dir2_data_unused_tag_p(newdup) =
+			cpu_to_be16((char *)newdup - (char *)hdr);
+		xfs_dir2_data_log_unused(args, bp, newdup);
+		/*
+		 * If it was in the table, remove it and add the new one.
+		 */
+		if (dfp) {
+			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
+			dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
+						       needlogp);
+			ASSERT(dfp != NULL);
+			ASSERT(dfp->length == newdup->length);
+			ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
+			/*
+			 * If we got inserted at the last slot,
+			 * that means we don't know if there was a better
+			 * choice for the last slot, or not.  Rescan.
+			 */
+			needscan = dfp == &bf[2];
+		}
+	}
+	/*
+	 * We match the last part of the entry.
+	 * Trim the allocated space off the tail of the entry.
+	 */
+	else if (matchback) {
+		newdup = dup;
+		newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
+		*xfs_dir2_data_unused_tag_p(newdup) =
+			cpu_to_be16((char *)newdup - (char *)hdr);
+		xfs_dir2_data_log_unused(args, bp, newdup);
+		/*
+		 * If it was in the table, remove it and add the new one.
+		 */
+		if (dfp) {
+			xfs_dir2_data_freeremove(hdr, bf, dfp, needlogp);
+			dfp = xfs_dir2_data_freeinsert(hdr, bf, newdup,
+						       needlogp);
+			ASSERT(dfp != NULL);
+			ASSERT(dfp->length == newdup->length);
+			ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)hdr);
+			/*
+			 * If we got inserted at the last slot,
+			 * that means we don't know if there was a better
+			 * choice for the last slot, or not.  Rescan.
+			 */
+			needscan = dfp == &bf[2];
+		}
+	}
+	/*
+	 * Poking out the middle of an entry.
+	 * Make two new entries.
+	 */
+	else {
+		newdup = dup;
+		newdup->length = cpu_to_be16(((char *)hdr + offset) - (char *)newdup);
+		*xfs_dir2_data_unused_tag_p(newdup) =
+			cpu_to_be16((char *)newdup - (char *)hdr);
+		xfs_dir2_data_log_unused(args, bp, newdup);
+		newdup2 = (xfs_dir2_data_unused_t *)((char *)hdr + offset + len);
+		newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
+		newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
+		*xfs_dir2_data_unused_tag_p(newdup2) =
+			cpu_to_be16((char *)newdup2 - (char *)hdr);
+		xfs_dir2_data_log_unused(args, bp, newdup2);
+		/*
+		 * If the old entry was in the table, we need to scan
+		 * if the 3rd entry was valid, since these entries
+		 * are smaller than the old one.
+		 * If we don't need to scan that means there were 1 or 2
+		 * entries in the table, and removing the old and adding
+		 * the 2 new will work.
+		 */
+		if (dfp) {
+			needscan = (bf[2].length != 0);
+			if (!needscan) {
+				xfs_dir2_data_freeremove(hdr, bf, dfp,
+							 needlogp);
+				xfs_dir2_data_freeinsert(hdr, bf, newdup,
+							 needlogp);
+				xfs_dir2_data_freeinsert(hdr, bf, newdup2,
+							 needlogp);
+			}
+		}
+	}
+	*needscanp = needscan;
+}