xfs: avoid usage of struct xfs_dir2_block

In most places we can simply pass around and use the struct xfs_dir2_data_hdr,
which is the first and most important member of struct xfs_dir2_block instead
of the full structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/xfs_dir2_block.h

@@ -61,10 +61,9 @@ typedef struct xfs_dir2_block {
  * Pointer to the leaf header embedded in a data block (1-block format)
  */
 static inline xfs_dir2_block_tail_t *
-xfs_dir2_block_tail_p(struct xfs_mount *mp, xfs_dir2_block_t *block)
+xfs_dir2_block_tail_p(struct xfs_mount *mp, xfs_dir2_data_hdr_t *hdr)
 {
-	return (((xfs_dir2_block_tail_t *)
-		((char *)(block) + (mp)->m_dirblksize)) - 1);
+	return ((xfs_dir2_block_tail_t *)((char *)hdr + mp->m_dirblksize)) - 1;
 }
 
 /*

fs/xfs/xfs_dir2_data.c

@@ -72,7 +72,7 @@ xfs_dir2_data_check(
 	bf = d->hdr.bestfree;
 	p = (char *)d->u;
 	if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
-		btp = xfs_dir2_block_tail_p(mp, (xfs_dir2_block_t *)d);
+		btp = xfs_dir2_block_tail_p(mp, &d->hdr);
 		lep = xfs_dir2_block_leaf_p(btp);
 		endp = (char *)lep;
 	} else
@@ -348,7 +348,7 @@ xfs_dir2_data_freescan(
 	 */
 	p = (char *)d->u;
 	if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
-		btp = xfs_dir2_block_tail_p(mp, (xfs_dir2_block_t *)d);
+		btp = xfs_dir2_block_tail_p(mp, &d->hdr);
 		endp = (char *)xfs_dir2_block_leaf_p(btp);
 	} else
 		endp = (char *)d + mp->m_dirblksize;
@@ -537,7 +537,7 @@ xfs_dir2_data_make_free(
 		xfs_dir2_block_tail_t	*btp;	/* block tail */
 
 		ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
-		btp = xfs_dir2_block_tail_p(mp, (xfs_dir2_block_t *)d);
+		btp = xfs_dir2_block_tail_p(mp, &d->hdr);
 		endptr = (char *)xfs_dir2_block_leaf_p(btp);
 	}
 	/*

fs/xfs/xfs_dir2_leaf.c

@@ -64,7 +64,7 @@ xfs_dir2_block_to_leaf(
 {
 	__be16			*bestsp;	/* leaf's bestsp entries */
 	xfs_dablk_t		blkno;		/* leaf block's bno */
-	xfs_dir2_block_t	*block;		/* block structure */
+	xfs_dir2_data_hdr_t	*hdr;		/* block header */
 	xfs_dir2_leaf_entry_t	*blp;		/* block's leaf entries */
 	xfs_dir2_block_tail_t	*btp;		/* block's tail */
 	xfs_inode_t		*dp;		/* incore directory inode */
@@ -101,9 +101,9 @@ xfs_dir2_block_to_leaf(
 	}
 	ASSERT(lbp != NULL);
 	leaf = lbp->data;
-	block = dbp->data;
+	hdr = dbp->data;
 	xfs_dir2_data_check(dp, dbp);
-	btp = xfs_dir2_block_tail_p(mp, block);
+	btp = xfs_dir2_block_tail_p(mp, hdr);
 	blp = xfs_dir2_block_leaf_p(btp);
 	/*
 	 * Set the counts in the leaf header.
@@ -123,23 +123,23 @@ xfs_dir2_block_to_leaf(
 	 * tail be free.
 	 */
 	xfs_dir2_data_make_free(tp, dbp,
-		(xfs_dir2_data_aoff_t)((char *)blp - (char *)block),
-		(xfs_dir2_data_aoff_t)((char *)block + mp->m_dirblksize -
+		(xfs_dir2_data_aoff_t)((char *)blp - (char *)hdr),
+		(xfs_dir2_data_aoff_t)((char *)hdr + mp->m_dirblksize -
 				       (char *)blp),
 		&needlog, &needscan);
 	/*
 	 * Fix up the block header, make it a data block.
 	 */
-	block->hdr.magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
+	hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
 	if (needscan)
-		xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)block, &needlog);
+		xfs_dir2_data_freescan(mp, (xfs_dir2_data_t *)hdr, &needlog);
 	/*
 	 * Set up leaf tail and bests table.
 	 */
 	ltp = xfs_dir2_leaf_tail_p(mp, leaf);
 	ltp->bestcount = cpu_to_be32(1);
 	bestsp = xfs_dir2_leaf_bests_p(ltp);
-	bestsp[0] =  block->hdr.bestfree[0].length;
+	bestsp[0] =  hdr->bestfree[0].length;
 	/*
 	 * Log the data header and leaf bests table.
 	 */

fs/xfs/xfs_dir2_sf.c

@@ -141,7 +141,7 @@ xfs_dir2_sfe_put_ino(
 int						/* size for sf form */
 xfs_dir2_block_sfsize(
 	xfs_inode_t		*dp,		/* incore inode pointer */
-	xfs_dir2_block_t	*block,		/* block directory data */
+	xfs_dir2_data_hdr_t	*hdr,		/* block directory data */
 	xfs_dir2_sf_hdr_t	*sfhp)		/* output: header for sf form */
 {
 	xfs_dir2_dataptr_t	addr;		/* data entry address */
@@ -161,7 +161,7 @@ xfs_dir2_block_sfsize(
 	mp = dp->i_mount;
 
 	count = i8count = namelen = 0;
-	btp = xfs_dir2_block_tail_p(mp, block);
+	btp = xfs_dir2_block_tail_p(mp, hdr);
 	blp = xfs_dir2_block_leaf_p(btp);
 
 	/*
@@ -174,7 +174,7 @@ xfs_dir2_block_sfsize(
 		 * Calculate the pointer to the entry at hand.
 		 */
 		dep = (xfs_dir2_data_entry_t *)
-		      ((char *)block + xfs_dir2_dataptr_to_off(mp, addr));
+		      ((char *)hdr + xfs_dir2_dataptr_to_off(mp, addr));
 		/*
 		 * Detect . and .., so we can special-case them.
 		 * . is not included in sf directories.
@@ -255,6 +255,7 @@ xfs_dir2_block_to_sf(
 		ASSERT(error != ENOSPC);
 		goto out;
 	}
+
 	/*
 	 * The buffer is now unconditionally gone, whether
 	 * xfs_dir2_shrink_inode worked or not.
@@ -276,7 +277,7 @@ xfs_dir2_block_to_sf(
 	/*
 	 * Set up to loop over the block's entries.
 	 */
-	btp = xfs_dir2_block_tail_p(mp, block);
+	btp = xfs_dir2_block_tail_p(mp, &block->hdr);
 	ptr = (char *)block->u;
 	endptr = (char *)xfs_dir2_block_leaf_p(btp);
 	sfep = xfs_dir2_sf_firstentry(sfp);

fs/xfs/xfs_dir2_sf.h

@@ -32,7 +32,7 @@
 struct uio;
 struct xfs_dabuf;
 struct xfs_da_args;
-struct xfs_dir2_block;
+struct xfs_dir2_data_hdr;
 struct xfs_inode;
 struct xfs_mount;
 struct xfs_trans;
@@ -136,7 +136,7 @@ extern xfs_ino_t xfs_dir2_sf_get_parent_ino(struct xfs_dir2_sf_hdr *sfp);
 extern xfs_ino_t xfs_dir2_sfe_get_ino(struct xfs_dir2_sf_hdr *sfp,
 				      struct xfs_dir2_sf_entry *sfep);
 extern int xfs_dir2_block_sfsize(struct xfs_inode *dp,
-				 struct xfs_dir2_block *block,
+				 struct xfs_dir2_data_hdr *block,
 				 xfs_dir2_sf_hdr_t *sfhp);
 extern int xfs_dir2_block_to_sf(struct xfs_da_args *args, struct xfs_dabuf *bp,
 				int size, xfs_dir2_sf_hdr_t *sfhp);