If the FS has no reflink, then atomic writes greater than 1x block are not
supported. As such, for no reflink it is pointless to accept setting
max_atomic_write when it cannot be supported, so reject max_atomic_write
mount option in this case.
It could be still possible to accept max_atomic_write option of size 1x
block if HW atomics are supported, so check for this specifically.
Fixes: 4528b9052731 ("xfs: allow sysadmins to specify a maximum atomic write limit at mount time")
Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
---
fs/xfs/xfs_mount.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 0b690bc119d7..1ec70f4e57b4 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -784,6 +784,25 @@ xfs_set_max_atomic_write_opt(
return -EINVAL;
}
+ if (xfs_has_reflink(mp))
+ goto set_limit;
+
+ if (new_max_fsbs == 1) {
+ if (mp->m_ddev_targp->bt_awu_max ||
+ (mp->m_rtdev_targp && mp->m_rtdev_targp->bt_awu_max)) {
+ } else {
+ xfs_warn(mp,
+ "cannot support atomic writes of size %lluk with no reflink or HW support",
+ new_max_bytes >> 10);
+ return -EINVAL;
+ }
+ } else {
+ xfs_warn(mp,
+ "cannot support atomic writes of size %lluk with no reflink support",
+ new_max_bytes >> 10);
+ return -EINVAL;
+ }
+
set_limit:
error = xfs_calc_atomic_write_reservation(mp, new_max_fsbs);
if (error) {
--
2.43.5
