btrfs: simplify fs_devices member access in btrfs_init_dev_replace_tgtdev

In btrfs_init_dev_replace_tgtdev() we dereference fs_info to get
fs_devices many times, instead save a point to the fs_devices.

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

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 62b9651..1bd1bce 100644 (file)
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -243,6 +243,7 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
                                  struct btrfs_device *srcdev,
                                  struct btrfs_device **device_out)
 {
+       struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
        struct btrfs_device *device;
        struct block_device *bdev;
        struct rcu_string *name;
@@ -271,7 +272,7 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
 
        sync_blockdev(bdev);
 
-       list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
+       list_for_each_entry(device, &fs_devices->devices, dev_list) {
                if (device->bdev == bdev) {
                        btrfs_err(fs_info,
                                  "target device is in the filesystem!");
@@ -320,17 +321,17 @@ static int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
        device->mode = FMODE_EXCL;
        device->dev_stats_valid = 1;
        set_blocksize(device->bdev, BTRFS_BDEV_BLOCKSIZE);
-       device->fs_devices = fs_info->fs_devices;
+       device->fs_devices = fs_devices;
 
        ret = btrfs_get_dev_zone_info(device, false);
        if (ret)
                goto error;
 
-       mutex_lock(&fs_info->fs_devices->device_list_mutex);
-       list_add(&device->dev_list, &fs_info->fs_devices->devices);
-       fs_info->fs_devices->num_devices++;
-       fs_info->fs_devices->open_devices++;
-       mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+       mutex_lock(&fs_devices->device_list_mutex);
+       list_add(&device->dev_list, &fs_devices->devices);
+       fs_devices->num_devices++;
+       fs_devices->open_devices++;
+       mutex_unlock(&fs_devices->device_list_mutex);
 
        *device_out = device;
        return 0;