btrfs: remove redundant btrfs_balance_control::fs_info

The fs_info is always available from the context so we don't need to
store it in the structure.
Reviewed-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/ioctl.c

@@ -4428,7 +4428,6 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)
 		goto out_bargs;
 	}
 
-	bctl->fs_info = fs_info;
 	if (arg) {
 		memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
 		memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
@@ -4454,7 +4453,7 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)
 	 */
 	need_unlock = false;
 
-	ret = btrfs_balance(bctl, bargs);
+	ret = btrfs_balance(fs_info, bctl, bargs);
 	bctl = NULL;
 
 	if (arg) {

fs/btrfs/volumes.c

@@ -3769,10 +3769,10 @@ static inline int validate_convert_profile(struct btrfs_balance_args *bctl_arg,
 /*
  * Should be called with balance mutexe held
  */
-int btrfs_balance(struct btrfs_balance_control *bctl,
+int btrfs_balance(struct btrfs_fs_info *fs_info,
+		  struct btrfs_balance_control *bctl,
 		  struct btrfs_ioctl_balance_args *bargs)
 {
-	struct btrfs_fs_info *fs_info = bctl->fs_info;
 	u64 meta_target, data_target;
 	u64 allowed;
 	int mixed = 0;
@@ -3940,7 +3940,7 @@ static int balance_kthread(void *data)
 	mutex_lock(&fs_info->balance_mutex);
 	if (fs_info->balance_ctl) {
 		btrfs_info(fs_info, "continuing balance");
-		ret = btrfs_balance(fs_info->balance_ctl, NULL);
+		ret = btrfs_balance(fs_info, fs_info->balance_ctl, NULL);
 	}
 	mutex_unlock(&fs_info->balance_mutex);
 
@@ -4011,7 +4011,6 @@ int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
 	leaf = path->nodes[0];
 	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
 
-	bctl->fs_info = fs_info;
 	bctl->flags = btrfs_balance_flags(leaf, item);
 	bctl->flags |= BTRFS_BALANCE_RESUME;
 

fs/btrfs/volumes.h

@@ -352,8 +352,6 @@ struct map_lookup {
 struct btrfs_balance_args;
 struct btrfs_balance_progress;
 struct btrfs_balance_control {
-	struct btrfs_fs_info *fs_info;
-
 	struct btrfs_balance_args data;
 	struct btrfs_balance_args meta;
 	struct btrfs_balance_args sys;
@@ -432,7 +430,8 @@ struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
 				       u8 *uuid, u8 *fsid);
 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
-int btrfs_balance(struct btrfs_balance_control *bctl,
+int btrfs_balance(struct btrfs_fs_info *fs_info,
+		  struct btrfs_balance_control *bctl,
 		  struct btrfs_ioctl_balance_args *bargs);
 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
 int btrfs_recover_balance(struct btrfs_fs_info *fs_info);