btrfs: cleanup btrfs_rm_device() promote fs_devices pointer

This function uses fs_info::fs_devices number of time, however we
declare and use it only at the end, instead do it in the beginning of
the function and use it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index bae1d2a7b2329f31a9491e3a957ddf985ce7d42b..70a87d4fe5fe5e2676c8ce5f43cfab71d2e70a4d 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1950,13 +1950,14 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
 {
        struct btrfs_device *device;
        struct btrfs_fs_devices *cur_devices;
+       struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
        u64 num_devices;
        int ret = 0;
 
        mutex_lock(&fs_info->volume_mutex);
        mutex_lock(&uuid_mutex);
 
-       num_devices = fs_info->fs_devices->num_devices;
+       num_devices = fs_devices->num_devices;
        btrfs_dev_replace_read_lock(&fs_info->dev_replace);
        if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
                WARN_ON(num_devices < 1);
@@ -2020,7 +2021,7 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
         */
 
        cur_devices = device->fs_devices;
-       mutex_lock(&fs_info->fs_devices->device_list_mutex);
+       mutex_lock(&fs_devices->device_list_mutex);
        list_del_rcu(&device->dev_list);
 
        device->fs_devices->num_devices--;
@@ -2034,12 +2035,12 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
        if (device->bdev) {
                device->fs_devices->open_devices--;
                /* remove sysfs entry */
-               btrfs_sysfs_rm_device_link(fs_info->fs_devices, device);
+               btrfs_sysfs_rm_device_link(fs_devices, device);
        }
 
        num_devices = btrfs_super_num_devices(fs_info->super_copy) - 1;
        btrfs_set_super_num_devices(fs_info->super_copy, num_devices);
-       mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+       mutex_unlock(&fs_devices->device_list_mutex);
 
        /*
         * at this point, the device is zero sized and detached from
@@ -2053,8 +2054,6 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path,
        call_rcu(&device->rcu, free_device_rcu);
 
        if (cur_devices->open_devices == 0) {
-               struct btrfs_fs_devices *fs_devices;
-               fs_devices = fs_info->fs_devices;
                while (fs_devices) {
                        if (fs_devices->seed == cur_devices) {
                                fs_devices->seed = cur_devices->seed;
@@ -2076,7 +2075,7 @@ error_undo:
        if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
                mutex_lock(&fs_info->chunk_mutex);
                list_add(&device->dev_alloc_list,
-                        &fs_info->fs_devices->alloc_list);
+                        &fs_devices->alloc_list);
                device->fs_devices->rw_devices++;
                mutex_unlock(&fs_info->chunk_mutex);
        }