xfs: check xfs_buf_read_uncached returns correctly
xfs_buf_read_uncached() has two failure modes. If can either return
NULL or bp->b_error != 0 depending on the type of failure, and not
all callers check for both. Fix it so that xfs_buf_read_uncached()
always returns the error status, and the buffer is returned as a
function parameter. The buffer will only be returned on success.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index d99ec83..6fbcbbf 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -688,29 +688,39 @@
* Read an uncached buffer from disk. Allocates and returns a locked
* buffer containing the disk contents or nothing.
*/
-struct xfs_buf *
+int
xfs_buf_read_uncached(
struct xfs_buftarg *target,
xfs_daddr_t daddr,
size_t numblks,
int flags,
+ struct xfs_buf **bpp,
const struct xfs_buf_ops *ops)
{
struct xfs_buf *bp;
+ *bpp = NULL;
+
bp = xfs_buf_get_uncached(target, numblks, flags);
if (!bp)
- return NULL;
+ return -ENOMEM;
/* set up the buffer for a read IO */
ASSERT(bp->b_map_count == 1);
- bp->b_bn = daddr;
+ bp->b_bn = XFS_BUF_DADDR_NULL; /* always null for uncached buffers */
bp->b_maps[0].bm_bn = daddr;
bp->b_flags |= XBF_READ;
bp->b_ops = ops;
xfs_buf_submit_wait(bp);
- return bp;
+ if (bp->b_error) {
+ int error = bp->b_error;
+ xfs_buf_relse(bp);
+ return error;
+ }
+
+ *bpp = bp;
+ return 0;
}
/*