[PATCH v2 1/2] btrfs: add function to device list delete

Anand Jain
2017-11-18T14:03:28Z

We need device delete from the dev_list so create a new function,
instead of refactor of btrfs_free_stale_device() because,
btrfs_free_stale_device() doesn't hold device_list_mutex which
is actually needed here.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
v1: title of this patch
btrfs: refactor btrfs_free_stale_device() to get device list delete
v2:
add new function instead of peal from
btrfs_free_stale_device() to delete a device from the device list,
since btrfs_free_stale_device() does not hold device_list_mutex,
may be it can be fixed later.

/btrfs/volumes.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index bddf75d5e6a0..68f1dd44385b 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -546,6 +546,27 @@ static void pending_bios_fn(struct btrfs_work *work)
run_scheduled_bios(device);
}

+static void delete_device_from_list(struct btrfs_device *device)
+{
+ struct btrfs_fs_devices *fs_devices;
+ fs_devices = device->fs_devices;
+
+ lockdep_assert_held(&uuid_mutex);
+
+ mutex_lock(&fs_devices->device_list_mutex);
+ fs_devices->num_devices--;
+ list_del(&device->dev_list);
+ mutex_unlock(&fs_devices->device_list_mutex);
+
+ rcu_string_free(device->name);
+ kfree(device);
+
+ if (fs_devices->num_devices == 0) {
+ btrfs_sysfs_remove_fsid(fs_devices);
+ list_del(&fs_devices->list);
+ free_fs_devices(fs_devices);
+ }
+}

void btrfs_free_stale_device(struct btrfs_device *cur_dev)
{
--
2.15.0