Btrfs: Replace the transaction work queue with kthreads

This creates one kthread for commits and one kthread for
deleting old snapshots.  All the work queues are removed.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 869864ddcc29..4e7cee27aab5 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -271,13 +271,17 @@ again:
         list_for_each(cur, head) {
                 device = list_entry(cur, struct btrfs_device, dev_list);
                 if (!device->in_fs_metadata) {
-                        if (device->bdev) {
-                                close_bdev_excl(device->bdev);
-                                fs_devices->open_devices--;
-                        }
+                        struct block_device *bdev;
                         list_del(&device->dev_list);
                         list_del(&device->dev_alloc_list);
                         fs_devices->num_devices--;
+                        if (device->bdev) {
+                                bdev = device->bdev;
+                                fs_devices->open_devices--;
+                                mutex_unlock(&uuid_mutex);
+                                close_bdev_excl(bdev);
+                                mutex_lock(&uuid_mutex);
+                        }
                         kfree(device->name);
                         kfree(device);
                         goto again;