xfs: factor and verify attr leaf reads

Some reads are not converted yet because it isn't obvious ahead of
time what the format of the block is going to be. Need to determine
how to tell if the first block in the tree is a node or leaf format
block. That will be done in later patches.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
diff --git a/fs/xfs/xfs_attr.c b/fs/xfs/xfs_attr.c
index cd5a9cd..d644915 100644
--- a/fs/xfs/xfs_attr.c
+++ b/fs/xfs/xfs_attr.c
@@ -903,11 +903,9 @@
 	 */
 	dp = args->dp;
 	args->blkno = 0;
-	error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1, &bp,
-					     XFS_ATTR_FORK, NULL);
+	error = xfs_attr_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
 	if (error)
-		return(error);
-	ASSERT(bp != NULL);
+		return error;
 
 	/*
 	 * Look up the given attribute in the leaf block.  Figure out if
@@ -1031,12 +1029,12 @@
 		 * Read in the block containing the "old" attr, then
 		 * remove the "old" attr from that block (neat, huh!)
 		 */
-		error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1,
-						     &bp, XFS_ATTR_FORK, NULL);
+		error = xfs_attr_leaf_read(args->trans, args->dp, args->blkno,
+					   -1, &bp);
 		if (error)
-			return(error);
-		ASSERT(bp != NULL);
-		(void)xfs_attr_leaf_remove(bp, args);
+			return error;
+
+		xfs_attr_leaf_remove(bp, args);
 
 		/*
 		 * If the result is small enough, shrink it all into the inode.
@@ -1100,20 +1098,17 @@
 	 */
 	dp = args->dp;
 	args->blkno = 0;
-	error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1, &bp,
-					     XFS_ATTR_FORK, NULL);
-	if (error) {
-		return(error);
-	}
+	error = xfs_attr_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
+	if (error)
+		return error;
 
-	ASSERT(bp != NULL);
 	error = xfs_attr_leaf_lookup_int(bp, args);
 	if (error == ENOATTR) {
 		xfs_trans_brelse(args->trans, bp);
 		return(error);
 	}
 
-	(void)xfs_attr_leaf_remove(bp, args);
+	xfs_attr_leaf_remove(bp, args);
 
 	/*
 	 * If the result is small enough, shrink it all into the inode.
@@ -1158,11 +1153,9 @@
 	trace_xfs_attr_leaf_get(args);
 
 	args->blkno = 0;
-	error = xfs_da_read_buf(args->trans, args->dp, args->blkno, -1, &bp,
-					     XFS_ATTR_FORK, NULL);
+	error = xfs_attr_leaf_read(args->trans, args->dp, args->blkno, -1, &bp);
 	if (error)
-		return(error);
-	ASSERT(bp != NULL);
+		return error;
 
 	error = xfs_attr_leaf_lookup_int(bp, args);
 	if (error != EEXIST)  {
@@ -1183,25 +1176,15 @@
 STATIC int
 xfs_attr_leaf_list(xfs_attr_list_context_t *context)
 {
-	xfs_attr_leafblock_t *leaf;
 	int error;
 	struct xfs_buf *bp;
 
 	trace_xfs_attr_leaf_list(context);
 
 	context->cursor->blkno = 0;
-	error = xfs_da_read_buf(NULL, context->dp, 0, -1, &bp, XFS_ATTR_FORK,
-				NULL);
+	error = xfs_attr_leaf_read(NULL, context->dp, 0, -1, &bp);
 	if (error)
 		return XFS_ERROR(error);
-	ASSERT(bp != NULL);
-	leaf = bp->b_addr;
-	if (unlikely(leaf->hdr.info.magic != cpu_to_be16(XFS_ATTR_LEAF_MAGIC))) {
-		XFS_CORRUPTION_ERROR("xfs_attr_leaf_list", XFS_ERRLEVEL_LOW,
-				     context->dp->i_mount, leaf);
-		xfs_trans_brelse(NULL, bp);
-		return XFS_ERROR(EFSCORRUPTED);
-	}
 
 	error = xfs_attr_leaf_list_int(bp, context);
 	xfs_trans_brelse(NULL, bp);
@@ -1605,12 +1588,9 @@
 		ASSERT(state->path.blk[0].bp);
 		state->path.blk[0].bp = NULL;
 
-		error = xfs_da_read_buf(args->trans, args->dp, 0, -1, &bp,
-						     XFS_ATTR_FORK, NULL);
+		error = xfs_attr_leaf_read(args->trans, args->dp, 0, -1, &bp);
 		if (error)
 			goto out;
-		ASSERT((((xfs_attr_leafblock_t *)bp->b_addr)->hdr.info.magic) ==
-		       cpu_to_be16(XFS_ATTR_LEAF_MAGIC));
 
 		if ((forkoff = xfs_attr_shortform_allfit(bp, dp))) {
 			xfs_bmap_init(args->flist, args->firstblock);
@@ -1920,14 +1900,6 @@
 	 */
 	for (;;) {
 		leaf = bp->b_addr;
-		if (unlikely(leaf->hdr.info.magic !=
-			     cpu_to_be16(XFS_ATTR_LEAF_MAGIC))) {
-			XFS_CORRUPTION_ERROR("xfs_attr_node_list(4)",
-					     XFS_ERRLEVEL_LOW,
-					     context->dp->i_mount, leaf);
-			xfs_trans_brelse(NULL, bp);
-			return(XFS_ERROR(EFSCORRUPTED));
-		}
 		error = xfs_attr_leaf_list_int(bp, context);
 		if (error) {
 			xfs_trans_brelse(NULL, bp);
@@ -1937,16 +1909,10 @@
 			break;
 		cursor->blkno = be32_to_cpu(leaf->hdr.info.forw);
 		xfs_trans_brelse(NULL, bp);
-		error = xfs_da_read_buf(NULL, context->dp, cursor->blkno, -1,
-					      &bp, XFS_ATTR_FORK, NULL);
+		error = xfs_attr_leaf_read(NULL, context->dp, cursor->blkno, -1,
+					   &bp);
 		if (error)
-			return(error);
-		if (unlikely((bp == NULL))) {
-			XFS_ERROR_REPORT("xfs_attr_node_list(5)",
-					 XFS_ERRLEVEL_LOW,
-					 context->dp->i_mount);
-			return(XFS_ERROR(EFSCORRUPTED));
-		}
+			return error;
 	}
 	xfs_trans_brelse(NULL, bp);
 	return(0);