btrfs: remove super block argument from btrfs_iget_path()

It's pointless to pass a super block argument to btrfs_iget_path() because
we always pass a root and from it we can get the super block through:

   root->fs_info->sb

So remove the super block argument.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/btrfs_inode.h

@@ -574,8 +574,8 @@ void btrfs_free_inode(struct inode *inode);
 int btrfs_drop_inode(struct inode *inode);
 int __init btrfs_init_cachep(void);
 void __cold btrfs_destroy_cachep(void);
-struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
-			      struct btrfs_root *root, struct btrfs_path *path);
+struct inode *btrfs_iget_path(u64 ino, struct btrfs_root *root,
+			      struct btrfs_path *path);
 struct inode *btrfs_iget(u64 ino, struct btrfs_root *root);
 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
 				    struct page *page, u64 start, u64 len);

fs/btrfs/free-space-cache.c

@@ -82,7 +82,6 @@ static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
 					       struct btrfs_path *path,
 					       u64 offset)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_key key;
 	struct btrfs_key location;
 	struct btrfs_disk_key disk_key;
@@ -116,7 +115,7 @@ static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
 	 * sure NOFS is set to keep us from deadlocking.
 	 */
 	nofs_flag = memalloc_nofs_save();
-	inode = btrfs_iget_path(fs_info->sb, location.objectid, root, path);
+	inode = btrfs_iget_path(location.objectid, root, path);
 	btrfs_release_path(path);
 	memalloc_nofs_restore(nofs_flag);
 	if (IS_ERR(inode))

fs/btrfs/inode.c

@@ -5595,13 +5595,13 @@ static struct inode *btrfs_iget_locked(struct super_block *s, u64 ino,
  * allocator. NULL is also valid but may require an additional allocation
  * later.
  */
-struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
-			      struct btrfs_root *root, struct btrfs_path *path)
+struct inode *btrfs_iget_path(u64 ino, struct btrfs_root *root,
+			      struct btrfs_path *path)
 {
 	struct inode *inode;
 	int ret;
 
-	inode = btrfs_iget_locked(s, ino, root);
+	inode = btrfs_iget_locked(root->fs_info->sb, ino, root);
 	if (!inode)
 		return ERR_PTR(-ENOMEM);
 
@@ -5632,7 +5632,7 @@ struct inode *btrfs_iget_path(struct super_block *s, u64 ino,
 
 struct inode *btrfs_iget(u64 ino, struct btrfs_root *root)
 {
-	return btrfs_iget_path(root->fs_info->sb, ino, root, NULL);
+	return btrfs_iget_path(ino, root, NULL);
 }
 
 static struct inode *new_simple_dir(struct inode *dir,