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, 24 insertions, 26 deletions

diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 9fa37f245c43..48a15af4ec57 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -105,8 +105,8 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
  * to use for the second index (if one is created).
  * Will return 0 or -ENOMEM
  */
-int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, const char *name,
-			  int name_len, struct btrfs_inode *dir,
+int btrfs_insert_dir_item(struct btrfs_trans_handle *trans,
+			  const struct qstr *name, struct btrfs_inode *dir,
 			  struct btrfs_key *location, u8 type, u64 index)
 {
 	int ret = 0;
@@ -122,7 +122,7 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, const char *name,
 
 	key.objectid = btrfs_ino(dir);
 	key.type = BTRFS_DIR_ITEM_KEY;
-	key.offset = btrfs_name_hash(name, name_len);
+	key.offset = btrfs_name_hash(name->name, name->len);
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -130,9 +130,9 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, const char *name,
 
 	btrfs_cpu_key_to_disk(&disk_key, location);
 
-	data_size = sizeof(*dir_item) + name_len;
+	data_size = sizeof(*dir_item) + name->len;
 	dir_item = insert_with_overflow(trans, root, path, &key, data_size,
-					name, name_len);
+					name->name, name->len);
 	if (IS_ERR(dir_item)) {
 		ret = PTR_ERR(dir_item);
 		if (ret == -EEXIST)
@@ -144,11 +144,11 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, const char *name,
 	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 	btrfs_set_dir_type(leaf, dir_item, type);
 	btrfs_set_dir_data_len(leaf, dir_item, 0);
-	btrfs_set_dir_name_len(leaf, dir_item, name_len);
+	btrfs_set_dir_name_len(leaf, dir_item, name->len);
 	btrfs_set_dir_transid(leaf, dir_item, trans->transid);
 	name_ptr = (unsigned long)(dir_item + 1);
 
-	write_extent_buffer(leaf, name, name_ptr, name_len);
+	write_extent_buffer(leaf, name->name, name_ptr, name->len);
 	btrfs_mark_buffer_dirty(leaf);
 
 second_insert:
@@ -159,7 +159,7 @@ second_insert:
 	}
 	btrfs_release_path(path);
 
-	ret2 = btrfs_insert_delayed_dir_index(trans, name, name_len, dir,
+	ret2 = btrfs_insert_delayed_dir_index(trans, name->name, name->len, dir,
 					      &disk_key, type, index);
 out_free:
 	btrfs_free_path(path);
@@ -208,7 +208,7 @@ static struct btrfs_dir_item *btrfs_lookup_match_dir(
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 					     struct btrfs_root *root,
 					     struct btrfs_path *path, u64 dir,
-					     const char *name, int name_len,
+					     const struct qstr *name,
 					     int mod)
 {
 	struct btrfs_key key;
@@ -216,9 +216,10 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 
 	key.objectid = dir;
 	key.type = BTRFS_DIR_ITEM_KEY;
-	key.offset = btrfs_name_hash(name, name_len);
+	key.offset = btrfs_name_hash(name->name, name->len);
 
-	di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
+	di = btrfs_lookup_match_dir(trans, root, path, &key, name->name,
+				    name->len, mod);
 	if (IS_ERR(di) && PTR_ERR(di) == -ENOENT)
 		return NULL;
 
@@ -226,7 +227,7 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 }
 
 int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
-				   const char *name, int name_len)
+				   const struct qstr *name)
 {
 	int ret;
 	struct btrfs_key key;
@@ -242,9 +243,10 @@ int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
 
 	key.objectid = dir;
 	key.type = BTRFS_DIR_ITEM_KEY;
-	key.offset = btrfs_name_hash(name, name_len);
+	key.offset = btrfs_name_hash(name->name, name->len);
 
-	di = btrfs_lookup_match_dir(NULL, root, path, &key, name, name_len, 0);
+	di = btrfs_lookup_match_dir(NULL, root, path, &key, name->name,
+				    name->len, 0);
 	if (IS_ERR(di)) {
 		ret = PTR_ERR(di);
 		/* Nothing found, we're safe */
@@ -264,11 +266,8 @@ int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
 		goto out;
 	}
 
-	/*
-	 * see if there is room in the item to insert this
-	 * name
-	 */
-	data_size = sizeof(*di) + name_len;
+	/* See if there is room in the item to insert this name. */
+	data_size = sizeof(*di) + name->len;
 	leaf = path->nodes[0];
 	slot = path->slots[0];
 	if (data_size + btrfs_item_size(leaf, slot) +
@@ -305,8 +304,7 @@ struct btrfs_dir_item *
 btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 			    struct btrfs_root *root,
 			    struct btrfs_path *path, u64 dir,
-			    u64 index, const char *name, int name_len,
-			    int mod)
+			    u64 index, const struct qstr *name, int mod)
 {
 	struct btrfs_dir_item *di;
 	struct btrfs_key key;
@@ -315,7 +313,8 @@ btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 	key.type = BTRFS_DIR_INDEX_KEY;
 	key.offset = index;
 
-	di = btrfs_lookup_match_dir(trans, root, path, &key, name, name_len, mod);
+	di = btrfs_lookup_match_dir(trans, root, path, &key, name->name,
+				    name->len, mod);
 	if (di == ERR_PTR(-ENOENT))
 		return NULL;
 
@@ -323,9 +322,8 @@ btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 }
 
 struct btrfs_dir_item *
-btrfs_search_dir_index_item(struct btrfs_root *root,
-			    struct btrfs_path *path, u64 dirid,
-			    const char *name, int name_len)
+btrfs_search_dir_index_item(struct btrfs_root *root, struct btrfs_path *path,
+			    u64 dirid, const struct qstr *name)
 {
 	struct btrfs_dir_item *di;
 	struct btrfs_key key;
@@ -340,7 +338,7 @@ btrfs_search_dir_index_item(struct btrfs_root *root,
 			break;
 
 		di = btrfs_match_dir_item_name(root->fs_info, path,
-					       name, name_len);
+					       name->name, name->len);
 		if (di)
 			return di;
 	}