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

Christoph Hellwig
2019-11-16T18:22:24Z

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@lst.de>
---
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