Btrfs: Add a special device list for chunk allocations
This allows other code that needs to walk every device in the FS to do so
without locking against allocations.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index dfe7e8a..a2660d2 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -24,9 +24,12 @@
struct buffer_head;
struct btrfs_device {
struct list_head dev_list;
+ struct list_head dev_alloc_list;
struct btrfs_root *dev_root;
struct buffer_head *pending_io;
+
int barriers;
+
spinlock_t io_lock;
struct block_device *bdev;
@@ -70,7 +73,11 @@
u64 num_devices;
struct block_device *latest_bdev;
struct block_device *lowest_bdev;
+ /* all of the devices in the FS */
struct list_head devices;
+
+ /* devices not currently being allocated */
+ struct list_head alloc_list;
struct list_head list;
};