[PATCH 2/9] xfs: improve the xfs_dabuf_map calling conventions

[Christoph Hellwig <hch@xxxxxx>]

Use a flags argument with the XFS_DABUF_MAP_HOLE_OK flag to signal that
a hole is okay and not corruption, and return -ENOENT instead of the
nameless -1 to signal that case in the return value.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 fs/xfs/libxfs/xfs_da_btree.c | 25 +++++++++++++++----------
 fs/xfs/libxfs/xfs_da_btree.h |  3 +++
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c
index 681fba5731c2..c26f139bcf00 100644
--- a/fs/xfs/libxfs/xfs_da_btree.c
+++ b/fs/xfs/libxfs/xfs_da_btree.c
@@ -2571,7 +2571,7 @@ static int
 xfs_dabuf_map(
 	struct xfs_inode	*dp,
 	xfs_dablk_t		bno,
-	xfs_daddr_t		mappedbno,
+	unsigned int		flags,
 	int			whichfork,
 	struct xfs_buf_map	**map,
 	int			*nmaps)
@@ -2596,8 +2596,8 @@ xfs_dabuf_map(
 
 	if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
 		/* Caller ok with no mapping. */
-		if (mappedbno == -2) {
-			error = -1;
+		if (flags & XFS_DABUF_MAP_HOLE_OK) {
+			error = -ENOENT;
 			goto out;
 		}
 
@@ -2655,10 +2655,12 @@ xfs_da_get_buf(
 		goto done;
 	}
 
-	error = xfs_dabuf_map(dp, bno, mappedbno, whichfork, &mapp, &nmap);
+	error = xfs_dabuf_map(dp, bno,
+			mappedbno == -1 ? XFS_DABUF_MAP_HOLE_OK : 0,
+			whichfork, &mapp, &nmap);
 	if (error) {
 		/* mapping a hole is not an error, but we don't continue */
-		if (error == -1)
+		if (error == -ENOENT)
 			error = 0;
 		goto out_free;
 	}
@@ -2710,10 +2712,12 @@ xfs_da_read_buf(
 		goto done;
 	}
 
-	error = xfs_dabuf_map(dp, bno, mappedbno, whichfork, &mapp, &nmap);
+	error = xfs_dabuf_map(dp, bno,
+			mappedbno == -1 ? XFS_DABUF_MAP_HOLE_OK : 0,
+			whichfork, &mapp, &nmap);
 	if (error) {
 		/* mapping a hole is not an error, but we don't continue */
-		if (error == -1)
+		if (error == -ENOENT)
 			error = 0;
 		goto out_free;
 	}
@@ -2757,11 +2761,12 @@ xfs_da_reada_buf(
 
 	mapp = &map;
 	nmap = 1;
-	error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
-				&mapp, &nmap);
+	error = xfs_dabuf_map(dp, bno,
+			mappedbno == -1 ? XFS_DABUF_MAP_HOLE_OK : 0,
+			whichfork, &mapp, &nmap);
 	if (error) {
 		/* mapping a hole is not an error, but we don't continue */
-		if (error == -1)
+		if (error == -ENOENT)
 			error = 0;
 		goto out_free;
 	}
diff --git a/fs/xfs/libxfs/xfs_da_btree.h b/fs/xfs/libxfs/xfs_da_btree.h
index 5af4df71e92b..9ec0d0243e96 100644
--- a/fs/xfs/libxfs/xfs_da_btree.h
+++ b/fs/xfs/libxfs/xfs_da_btree.h
@@ -204,6 +204,9 @@ int	xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
 /*
  * Utility routines.
  */
+
+#define XFS_DABUF_MAP_HOLE_OK	(1 << 0)
+
 int	xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
 int	xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
 			      int count);
-- 
2.20.1