Btrfs: free btrfs_device in place

It's pointless to defer it to a kthread helper as we're not under a
special context.

For reference, commit 1f78160ce1b1 ("Btrfs: using rcu lock in the reader
side of devices list") introduced RCU freeing for device structures.

Originally the blkdev_put was called from free_device and rcu_barrier had
to be called. This is no longer required, bdev and our device structures
are now freed separately.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ enhance changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a256842875017b386a2a349f734f5feff7391484..f3c4ad2ddfe6324cd221d7b7795be1739dffc2be 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -824,26 +824,16 @@ again:
        mutex_unlock(&uuid_mutex);
 }
 
-static void __free_device(struct work_struct *work)
+static void free_device(struct rcu_head *head)
 {
        struct btrfs_device *device;
 
-       device = container_of(work, struct btrfs_device, rcu_work);
+       device = container_of(head, struct btrfs_device, rcu);
        rcu_string_free(device->name);
        bio_put(device->flush_bio);
        kfree(device);
 }
 
-static void free_device(struct rcu_head *head)
-{
-       struct btrfs_device *device;
-
-       device = container_of(head, struct btrfs_device, rcu);
-
-       INIT_WORK(&device->rcu_work, __free_device);
-       schedule_work(&device->rcu_work);
-}
-
 static void btrfs_close_bdev(struct btrfs_device *device)
 {
        if (device->bdev && device->writeable) {

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index ff15208344a7b0c7f2d05bff338c8b46bc2546a9..bf0d53a96b4a964c4a19d257ad780e65c0f3e726 100644 (file)
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -133,7 +133,6 @@ struct btrfs_device {
 
        struct btrfs_work work;
        struct rcu_head rcu;
-       struct work_struct rcu_work;
 
        /* readahead state */
        spinlock_t reada_lock;