btrfs: remove unused parameters from btrfs_lookup_inode_extref()

The function btrfs_lookup_inode_extref(` no longer requires transaction
handle, insert length, or COW flag, as the only caller now performs a
read-only lookup using trans == NULL, ins_len == 0 and cow == 0.

This function was introduced in the early days where extref feature was
introduced by commit f186373 ("btrfs: extended inode refs").
Then some cleanup was done in commit 33b98f2 ("btrfs: cleanup:
removed unused 'btrfs_get_inode_ref_index'"), which removed the only
caller passing trans and other COW specific options.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Sun YangKai <sunk67188@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: Sun YangKai

fs/btrfs/inode-item.c

@@ -78,13 +78,10 @@ struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
 }
 
 /* Returns NULL if no extref found */
-struct btrfs_inode_extref *
-btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root,
-			  struct btrfs_path *path,
-			  const struct fscrypt_str *name,
-			  u64 inode_objectid, u64 ref_objectid, int ins_len,
-			  int cow)
+struct btrfs_inode_extref *btrfs_lookup_inode_extref(struct btrfs_root *root,
+						     struct btrfs_path *path,
+						     const struct fscrypt_str *name,
+						     u64 inode_objectid, u64 ref_objectid)
 {
 	int ret;
 	struct btrfs_key key;
@@ -93,7 +90,7 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 	key.type = BTRFS_INODE_EXTREF_KEY;
 	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
 
-	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 	if (ret < 0)
 		return ERR_PTR(ret);
 	if (ret > 0)

fs/btrfs/inode-item.h

@@ -101,13 +101,10 @@ int btrfs_lookup_inode(struct btrfs_trans_handle *trans,
 		       struct btrfs_root *root, struct btrfs_path *path,
 		       struct btrfs_key *location, int mod);
 
-struct btrfs_inode_extref *btrfs_lookup_inode_extref(
-			  struct btrfs_trans_handle *trans,
-			  struct btrfs_root *root,
-			  struct btrfs_path *path,
-			  const struct fscrypt_str *name,
-			  u64 inode_objectid, u64 ref_objectid, int ins_len,
-			  int cow);
+struct btrfs_inode_extref *btrfs_lookup_inode_extref(struct btrfs_root *root,
+						     struct btrfs_path *path,
+						     const struct fscrypt_str *name,
+						     u64 inode_objectid, u64 ref_objectid);
 
 struct btrfs_inode_ref *btrfs_find_name_in_backref(const struct extent_buffer *leaf,
 						   int slot,

fs/btrfs/tree-log.c

@@ -1126,9 +1126,7 @@ static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
 	btrfs_release_path(path);
 
 	/* Same search but for extended refs */
-	extref = btrfs_lookup_inode_extref(NULL, root, path, name,
-					   inode_objectid, parent_objectid, 0,
-					   0);
+	extref = btrfs_lookup_inode_extref(root, path, name, inode_objectid, parent_objectid);
 	if (IS_ERR(extref)) {
 		return PTR_ERR(extref);
 	} else if (extref) {