It's pointless to defer it to a kthread helper as we're not under any
special context.
A bit more about device's lifetime, filesystems use an exclusive way
to access devices and hold a reference count on the devices in use.
Now that we've run blkdev_put() in btrfs_close_bdev(), device->bdev's
lifetime ends at btrfs_close_bdev(), not free_device(), and %bdev is
the only thing that others who need to access it really care about.
Since free_device() only frees the resources of 'struct btrfs_device',
this change won't result in the problem, ie. others like mkfs and md
are unable to access the device immediately after we do umount.
Signed-off-by: Liu Bo <bo.li....@oracle.com>
Reviewed-by: Anand Jain <anand.j...@oracle.com>
---
v2: Clarify the lifetime of device and device->bdev respectively and
clear the concern about raising the 'device is in use' problem.
fs/btrfs/volumes.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d983cea..4a72c45 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -836,26 +836,16 @@ void btrfs_close_extra_devices(struct btrfs_fs_devices
*fs_devices, int step)
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) {
--
2.9.4
--
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