xfs: remove the ->data_unused_p method

Replace the two users of the ->data_unused_p dir ops method with a
direct calculation using ->data_entry_offset, and clean them up a bit.
xfs_dir2_sf_to_block already had an offset variable containing the
value of ->data_entry_offset, which we are now reusing to make it
clear that the initial freespace entry is at the same place that
we later fill in the 1 entry, and in xfs_dir3_data_init the function
is cleaned up a bit to keep the initialization of fields of a given
structure close to each other, and to avoid a local variable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/libxfs/xfs_da_format.c

@@ -130,13 +130,6 @@ xfs_dir2_data_entry_p(struct xfs_dir2_data_hdr *hdr)
 		((char *)hdr + sizeof(struct xfs_dir2_data_hdr));
 }
 
-static struct xfs_dir2_data_unused *
-xfs_dir2_data_unused_p(struct xfs_dir2_data_hdr *hdr)
-{
-	return (struct xfs_dir2_data_unused *)
-		((char *)hdr + sizeof(struct xfs_dir2_data_hdr));
-}
-
 static struct xfs_dir2_data_entry *
 xfs_dir3_data_entry_p(struct xfs_dir2_data_hdr *hdr)
 {
@@ -144,13 +137,6 @@ xfs_dir3_data_entry_p(struct xfs_dir2_data_hdr *hdr)
 		((char *)hdr + sizeof(struct xfs_dir3_data_hdr));
 }
 
-static struct xfs_dir2_data_unused *
-xfs_dir3_data_unused_p(struct xfs_dir2_data_hdr *hdr)
-{
-	return (struct xfs_dir2_data_unused *)
-		((char *)hdr + sizeof(struct xfs_dir3_data_hdr));
-}
-
 static const struct xfs_dir_ops xfs_dir2_ops = {
 	.data_entsize = xfs_dir2_data_entsize,
 	.data_get_ftype = xfs_dir2_data_get_ftype,
@@ -164,7 +150,6 @@ static const struct xfs_dir_ops xfs_dir2_ops = {
 	.data_entry_offset = sizeof(struct xfs_dir2_data_hdr),
 
 	.data_entry_p = xfs_dir2_data_entry_p,
-	.data_unused_p = xfs_dir2_data_unused_p,
 };
 
 static const struct xfs_dir_ops xfs_dir2_ftype_ops = {
@@ -180,7 +165,6 @@ static const struct xfs_dir_ops xfs_dir2_ftype_ops = {
 	.data_entry_offset = sizeof(struct xfs_dir2_data_hdr),
 
 	.data_entry_p = xfs_dir2_data_entry_p,
-	.data_unused_p = xfs_dir2_data_unused_p,
 };
 
 static const struct xfs_dir_ops xfs_dir3_ops = {
@@ -196,7 +180,6 @@ static const struct xfs_dir_ops xfs_dir3_ops = {
 	.data_entry_offset = sizeof(struct xfs_dir3_data_hdr),
 
 	.data_entry_p = xfs_dir3_data_entry_p,
-	.data_unused_p = xfs_dir3_data_unused_p,
 };
 
 /*

fs/xfs/libxfs/xfs_dir2.h

@@ -45,8 +45,6 @@ struct xfs_dir_ops {
 
 	struct xfs_dir2_data_entry *
 		(*data_entry_p)(struct xfs_dir2_data_hdr *hdr);
-	struct xfs_dir2_data_unused *
-		(*data_unused_p)(struct xfs_dir2_data_hdr *hdr);
 };
 
 extern const struct xfs_dir_ops *

fs/xfs/libxfs/xfs_dir2_block.c

@@ -1112,7 +1112,7 @@ xfs_dir2_sf_to_block(
 	 * The whole thing is initialized to free by the init routine.
 	 * Say we're using the leaf and tail area.
 	 */
-	dup = dp->d_ops->data_unused_p(hdr);
+	dup = bp->b_addr + offset;
 	needlog = needscan = 0;
 	error = xfs_dir2_data_use_free(args, bp, dup, args->geo->blksize - i,
 			i, &needlog, &needscan);

fs/xfs/libxfs/xfs_dir2_data.c

@@ -631,24 +631,20 @@ xfs_dir2_data_freescan(
  */
 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_da_args		*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 */
+	struct xfs_trans		*tp = args->trans;
+	struct xfs_inode		*dp = args->dp;
+	struct xfs_mount		*mp = dp->i_mount;
+	struct xfs_buf			*bp;
+	struct xfs_dir2_data_hdr	*hdr;
+	struct xfs_dir2_data_unused	*dup;
+	struct xfs_dir2_data_free 	*bf;
+	int				error;
+	int				i;
 
-	dp = args->dp;
-	mp = dp->i_mount;
-	tp = args->trans;
 	/*
 	 * Get the buffer set up for the block.
 	 */
@@ -677,6 +673,8 @@ xfs_dir3_data_init(
 
 	bf = dp->d_ops->data_bestfree_p(hdr);
 	bf[0].offset = cpu_to_be16(dp->d_ops->data_entry_offset);
+	bf[0].length =
+		cpu_to_be16(args->geo->blksize - dp->d_ops->data_entry_offset);
 	for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
 		bf[i].length = 0;
 		bf[i].offset = 0;
@@ -685,13 +683,11 @@ xfs_dir3_data_init(
 	/*
 	 * Set up an unused entry for the block's body.
 	 */
-	dup = dp->d_ops->data_unused_p(hdr);
+	dup = bp->b_addr + dp->d_ops->data_entry_offset;
 	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);
+	dup->length = bf[0].length;
 	*xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)hdr);
+
 	/*
 	 * Log it and return it.
 	 */