Without this fix (and another to the userspace component itself
described later), the kernel will be unable to process any OrangeFS
requests after the userspace component is restarted (due to a crash or
at the administrator's behest).
The bug here is that inside orangefs_remount, the orangefs_request_mutex
is locked. When the userspace component restarts while the filesystem
is mounted, it sends a ORANGEFS_DEV_REMOUNT_ALL ioctl to the device,
which causes the kernel to send it a few requests aimed at synchronizing
the state between the two. While this is happening the
orangefs_request_mutex is locked to prevent any other requests going
through.
This is only half of the bugfix. The other half is in the userspace
component which outright ignores(!) requests made before it considers
the filesystem remounted, which is after the ioctl returns. Of course
the ioctl doesn't return until after the userspace component responds to
the request it ignores. The userspace component has been changed to
allow ORANGEFS_VFS_OP_FEATURES regardless of the mount status.
Signed-off-by: Martin Brandenburg <martin@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
fs/orangefs/super.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/fs/orangefs/super.c b/fs/orangefs/super.c
index 67c2435..cd261c8 100644
--- a/fs/orangefs/super.c
+++ b/fs/orangefs/super.c
@@ -263,8 +263,13 @@ int orangefs_remount(struct orangefs_sb_info_s *orangefs_sb)
if (!new_op)
return -ENOMEM;
new_op->upcall.req.features.features = 0;
- ret = service_operation(new_op, "orangefs_features", 0);
- orangefs_features = new_op->downcall.resp.features.features;
+ ret = service_operation(new_op, "orangefs_features",
+ ORANGEFS_OP_PRIORITY | ORANGEFS_OP_NO_MUTEX);
+ if (!ret)
+ orangefs_features =
+ new_op->downcall.resp.features.features;
+ else
+ orangefs_features = 0;
op_release(new_op);
} else {
orangefs_features = 0;
--
2.1.4