btrfs: use struct qstr instead of name and namelen pairs

Many functions throughout btrfs take name buffer and name length
arguments. Most of these functions at the highest level are usually
called with these arguments extracted from a supplied dentry's name.
But the entire name can be passed instead, making each function a little
more elegant.

Each function whose arguments are currently the name and length
extracted from a dentry is herein converted to instead take a pointer to
the name in the dentry. The couple of calls to these calls without a
struct dentry are converted to create an appropriate qstr to pass in.
Additionally, every function which is only called with a name/len
extracted directly from a qstr is also converted.

This change has positive effect on stack consumption, frame of many
functions is reduced but this will be used in the future for fscrypt
related structures.

Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 9 insertions, 10 deletions

diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index fc00dfb281d5..848a720747af 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -330,9 +330,8 @@ out:
 }
 
 int btrfs_del_root_ref(struct btrfs_trans_handle *trans, u64 root_id,
-		       u64 ref_id, u64 dirid, u64 *sequence, const char *name,
-		       int name_len)
-
+		       u64 ref_id, u64 dirid, u64 *sequence,
+		       const struct qstr *name)
 {
 	struct btrfs_root *tree_root = trans->fs_info->tree_root;
 	struct btrfs_path *path;
@@ -359,8 +358,8 @@ again:
 				     struct btrfs_root_ref);
 		ptr = (unsigned long)(ref + 1);
 		if ((btrfs_root_ref_dirid(leaf, ref) != dirid) ||
-		    (btrfs_root_ref_name_len(leaf, ref) != name_len) ||
-		    memcmp_extent_buffer(leaf, name, ptr, name_len)) {
+		    (btrfs_root_ref_name_len(leaf, ref) != name->len) ||
+		    memcmp_extent_buffer(leaf, name->name, ptr, name->len)) {
 			ret = -ENOENT;
 			goto out;
 		}
@@ -403,8 +402,8 @@ out:
  * Will return 0, -ENOMEM, or anything from the CoW path
  */
 int btrfs_add_root_ref(struct btrfs_trans_handle *trans, u64 root_id,
-		       u64 ref_id, u64 dirid, u64 sequence, const char *name,
-		       int name_len)
+		       u64 ref_id, u64 dirid, u64 sequence,
+		       const struct qstr *name)
 {
 	struct btrfs_root *tree_root = trans->fs_info->tree_root;
 	struct btrfs_key key;
@@ -423,7 +422,7 @@ int btrfs_add_root_ref(struct btrfs_trans_handle *trans, u64 root_id,
 	key.offset = ref_id;
 again:
 	ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
-				      sizeof(*ref) + name_len);
+				      sizeof(*ref) + name->len);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		btrfs_free_path(path);
@@ -434,9 +433,9 @@ again:
 	ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
 	btrfs_set_root_ref_dirid(leaf, ref, dirid);
 	btrfs_set_root_ref_sequence(leaf, ref, sequence);
-	btrfs_set_root_ref_name_len(leaf, ref, name_len);
+	btrfs_set_root_ref_name_len(leaf, ref, name->len);
 	ptr = (unsigned long)(ref + 1);
-	write_extent_buffer(leaf, name, ptr, name_len);
+	write_extent_buffer(leaf, name->name, ptr, name->len);
 	btrfs_mark_buffer_dirty(leaf);
 
 	if (key.type == BTRFS_ROOT_BACKREF_KEY) {