Merge branch 'xfs-dax-fixes-for-4.5' into for-next

1 files changed, 16 insertions, 9 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index f5392ab2def1..ebe9b8290a70 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -402,19 +402,26 @@ xfs_file_splice_read(
 	if (XFS_FORCED_SHUTDOWN(ip->i_mount))
 		return -EIO;
 
-	xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
-
 	trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
 
-	/* for dax, we need to avoid the page cache */
-	if (IS_DAX(VFS_I(ip)))
-		ret = default_file_splice_read(infilp, ppos, pipe, count, flags);
-	else
-		ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
-	if (ret > 0)
-		XFS_STATS_ADD(ip->i_mount, xs_read_bytes, ret);
+	/*
+	 * DAX inodes cannot ues the page cache for splice, so we have to push
+	 * them through the VFS IO path. This means it goes through
+	 * ->read_iter, which for us takes the XFS_IOLOCK_SHARED. Hence we
+	 * cannot lock the splice operation at this level for DAX inodes.
+	 */
+	if (IS_DAX(VFS_I(ip))) {
+		ret = default_file_splice_read(infilp, ppos, pipe, count,
+					       flags);
+		goto out;
+	}
 
+	xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
+	ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
 	xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
+out:
+	if (ret > 0)
+		XFS_STATS_ADD(ip->i_mount, xs_read_bytes, ret);
 	return ret;
 }