u64 rw_devices;
u64 total_rw_bytes;
struct block_device *latest_bdev;
- /* all of the devices in the FS */
+
+ /* all of the devices in the FS, protected by a mutex
+ * so we can safely walk it to write out the supers without
+ * worrying about add/remove by the multi-device code
+ */
+ struct mutex device_list_mutex;
struct list_head devices;
/* devices not currently being allocated */
int seeding;
int opened;
+
+ /* set when we find or add a device that doesn't have the
+ * nonrot flag set
+ */
+ int rotating;
};
struct btrfs_bio_stripe {