[XFS] use filldir internally

Currently xfs has a rather complicated internal scheme to allow for
different directory formats in IRIX. This patch rips all code related to
this out and pushes useage of the Linux filldir callback into the lowlevel
directory code. This does not make the code any less portable because
filldir can be used to create dirents of all possible variations
(including the IRIX ones as proved by the IRIX binary emulation code under
arch/mips/).

This patch get rid of an unessecary copy in the readdir path, about 400
lines of code and one of the last two users of the uio structure.

This version is updated to deal with dmapi aswell which greatly simplifies
the get_dirattrs code. The dmapi part has been tested using the
get_dirattrs tools from the xfstest dmapi suite1 with various small and
large directories.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29478a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
diff --git a/fs/xfs/xfs_dir2_block.c b/fs/xfs/xfs_dir2_block.c
index e4df1aa..f6b919a 100644
--- a/fs/xfs/xfs_dir2_block.c
+++ b/fs/xfs/xfs_dir2_block.c
@@ -432,12 +432,10 @@
  */
 int						/* error */
 xfs_dir2_block_getdents(
-	xfs_trans_t		*tp,		/* transaction (NULL) */
 	xfs_inode_t		*dp,		/* incore inode */
-	uio_t			*uio,		/* caller's buffer control */
-	int			*eofp,		/* eof reached? (out) */
-	xfs_dirent_t		*dbp,		/* caller's buffer */
-	xfs_dir2_put_t		put)		/* abi's formatting function */
+	void			*dirent,
+	xfs_off_t		*offset,
+	filldir_t		filldir)
 {
 	xfs_dir2_block_t	*block;		/* directory block structure */
 	xfs_dabuf_t		*bp;		/* buffer for block */
@@ -447,31 +445,32 @@
 	char			*endptr;	/* end of the data entries */
 	int			error;		/* error return value */
 	xfs_mount_t		*mp;		/* filesystem mount point */
-	xfs_dir2_put_args_t	p;		/* arg package for put rtn */
 	char			*ptr;		/* current data entry */
 	int			wantoff;	/* starting block offset */
+	xfs_ino_t		ino;
+	xfs_off_t		cook;
 
 	mp = dp->i_mount;
 	/*
 	 * If the block number in the offset is out of range, we're done.
 	 */
-	if (xfs_dir2_dataptr_to_db(mp, uio->uio_offset) > mp->m_dirdatablk) {
-		*eofp = 1;
+	if (xfs_dir2_dataptr_to_db(mp, *offset) > mp->m_dirdatablk) {
 		return 0;
 	}
 	/*
 	 * Can't read the block, give up, else get dabuf in bp.
 	 */
-	if ((error =
-	    xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, &bp, XFS_DATA_FORK))) {
+	error = xfs_da_read_buf(NULL, dp, mp->m_dirdatablk, -1,
+				&bp, XFS_DATA_FORK);
+	if (error)
 		return error;
-	}
+
 	ASSERT(bp != NULL);
 	/*
 	 * Extract the byte offset we start at from the seek pointer.
 	 * We'll skip entries before this.
 	 */
-	wantoff = xfs_dir2_dataptr_to_off(mp, uio->uio_offset);
+	wantoff = xfs_dir2_dataptr_to_off(mp, *offset);
 	block = bp->data;
 	xfs_dir2_data_check(dp, bp);
 	/*
@@ -480,9 +479,7 @@
 	btp = xfs_dir2_block_tail_p(mp, block);
 	ptr = (char *)block->u;
 	endptr = (char *)xfs_dir2_block_leaf_p(btp);
-	p.dbp = dbp;
-	p.put = put;
-	p.uio = uio;
+
 	/*
 	 * Loop over the data portion of the block.
 	 * Each object is a real entry (dep) or an unused one (dup).
@@ -508,33 +505,24 @@
 		 */
 		if ((char *)dep - (char *)block < wantoff)
 			continue;
-		/*
-		 * Set up argument structure for put routine.
-		 */
-		p.namelen = dep->namelen;
 
-		p.cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
+		cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
 						    ptr - (char *)block);
-		p.ino = be64_to_cpu(dep->inumber);
+		ino = be64_to_cpu(dep->inumber);
 #if XFS_BIG_INUMS
-		p.ino += mp->m_inoadd;
+		ino += mp->m_inoadd;
 #endif
-		p.name = (char *)dep->name;
-
-		/*
-		 * Put the entry in the caller's buffer.
-		 */
-		error = p.put(&p);
 
 		/*
 		 * If it didn't fit, set the final offset to here & return.
 		 */
-		if (!p.done) {
-			uio->uio_offset =
-				xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
+		if (filldir(dirent, dep->name, dep->namelen, cook,
+			    ino, DT_UNKNOWN)) {
+			*offset = xfs_dir2_db_off_to_dataptr(mp,
+					mp->m_dirdatablk,
 					(char *)dep - (char *)block);
-			xfs_da_brelse(tp, bp);
-			return error;
+			xfs_da_brelse(NULL, bp);
+			return 0;
 		}
 	}
 
@@ -542,13 +530,8 @@
 	 * Reached the end of the block.
 	 * Set the offset to a non-existent block 1 and return.
 	 */
-	*eofp = 1;
-
-	uio->uio_offset =
-		xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0);
-
-	xfs_da_brelse(tp, bp);
-
+	*offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0);
+	xfs_da_brelse(NULL, bp);
 	return 0;
 }