[PATCH 4.4 07/14] xfs: map unwritten blocks in XFS_IOC_{ALLOC,FREE}SP just like fallocate

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Darrick J. Wong <djwong@kernel.org>

commit 983d8e60f50806f90534cc5373d0ce867e5aaf79 upstream.

The old ALLOCSP/FREESP ioctls in XFS can be used to preallocate space at
the end of files, just like fallocate and RESVSP.  Make the behavior
consistent with the other ioctls.

Reported-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/xfs/xfs_ioctl.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -729,7 +729,8 @@ xfs_ioc_space(
 		flags |= XFS_PREALLOC_CLEAR;
 		if (bf->l_start > XFS_ISIZE(ip)) {
 			error = xfs_alloc_file_space(ip, XFS_ISIZE(ip),
-					bf->l_start - XFS_ISIZE(ip), 0);
+					bf->l_start - XFS_ISIZE(ip),
+					XFS_BMAPI_PREALLOC);
 			if (error)
 				goto out_unlock;
 		}