btrfs: take an fs_info directly when the root is not used otherwise

There are loads of functions in btrfs that accept a root parameter
but only use it to obtain an fs_info pointer.  Let's convert those to
just accept an fs_info pointer directly.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 724d18c..18b4449 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -408,10 +408,10 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info,
 int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
 int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
-		      struct btrfs_root *extent_root, u64 type);
+		      struct btrfs_fs_info *fs_info, u64 type);
 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
-int btrfs_map_bio(struct btrfs_root *root, struct bio *bio,
+int btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 		  int mirror_num, int async_submit);
 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		       fmode_t flags, void *holder);
@@ -421,16 +421,17 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step);
 void btrfs_assign_next_active_device(struct btrfs_fs_info *fs_info,
 		struct btrfs_device *device, struct btrfs_device *this_dev);
-int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
+int btrfs_find_device_missing_or_by_path(struct btrfs_fs_info *fs_info,
 					 char *device_path,
 					 struct btrfs_device **device);
-int btrfs_find_device_by_devspec(struct btrfs_root *root, u64 devid,
+int btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info, u64 devid,
 					 char *devpath,
 					 struct btrfs_device **device);
 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
 					const u64 *devid,
 					const u8 *uuid);
-int btrfs_rm_device(struct btrfs_root *root, char *device_path, u64 devid);
+int btrfs_rm_device(struct btrfs_fs_info *fs_info,
+		    char *device_path, u64 devid);
 void btrfs_cleanup_fs_uuids(void);
 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
 int btrfs_grow_device(struct btrfs_trans_handle *trans,
@@ -439,7 +440,8 @@ 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, char *path);
-int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
+int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
+				  char *device_path,
 				  struct btrfs_device *srcdev,
 				  struct btrfs_device **device_out);
 int btrfs_balance(struct btrfs_balance_control *bctl,
@@ -450,7 +452,7 @@ int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info);
-int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
+int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
 int find_free_dev_extent_start(struct btrfs_transaction *transaction,
 			 struct btrfs_device *device, u64 num_bytes,
 			 u64 search_start, u64 *start, u64 *max_avail);
@@ -458,7 +460,7 @@ int find_free_dev_extent(struct btrfs_trans_handle *trans,
 			 struct btrfs_device *device, u64 num_bytes,
 			 u64 *start, u64 *max_avail);
 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
-int btrfs_get_dev_stats(struct btrfs_root *root,
+int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
 			struct btrfs_ioctl_get_dev_stats *stats);
 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
@@ -475,7 +477,7 @@ void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
 void btrfs_scratch_superblocks(struct block_device *bdev, char *device_path);
 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
 			   u64 logical, u64 len, int mirror_num);
-unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
+unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
 				    struct btrfs_mapping_tree *map_tree,
 				    u64 logical);
 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
@@ -529,7 +531,7 @@ static inline void btrfs_dev_stat_reset(struct btrfs_device *dev,
 }
 
 void btrfs_update_commit_device_size(struct btrfs_fs_info *fs_info);
-void btrfs_update_commit_device_bytes_used(struct btrfs_root *root,
+void btrfs_update_commit_device_bytes_used(struct btrfs_fs_info *fs_info,
 					struct btrfs_transaction *transaction);
 
 static inline void lock_chunks(struct btrfs_fs_info *fs_info)