Btrfs: add DEVICE_READY ioctl
This will be used in conjunction with btrfs device ready <dev>. This is
needed for initrd's to have a nice and lightweight way to tell if all of the
devices needed for a file system are in the cache currently. This keeps
them from having to do mount+sleep loops waiting for devices to show up.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index e404414..5479325 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -126,6 +126,7 @@
u64 missing_devices;
u64 total_rw_bytes;
u64 num_can_discard;
+ u64 total_devices;
struct block_device *latest_bdev;
/* all of the devices in the FS, protected by a mutex