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>

12 files changed, 287 insertions, 335 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3dcfb62af68a..9e8c9f9bc4fb 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1516,11 +1516,11 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 
 /* root-item.c */
 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);
 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);
 int btrfs_del_root(struct btrfs_trans_handle *trans,
 		   const struct btrfs_key *key);
 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -1549,25 +1549,23 @@ int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info);
 
 /* dir-item.c */
 int btrfs_check_dir_item_collision(struct btrfs_root *root, u64 dir,
-			  const char *name, int name_len);
-int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, const char *name,
-			  int name_len, struct btrfs_inode *dir,
+			  const struct qstr *name);
+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);
 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,
-					     int mod);
+					     const struct qstr *name, int mod);
 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 *
 btrfs_search_dir_index_item(struct btrfs_root *root,
 			    struct btrfs_path *path, u64 dirid,
-			    const char *name, int name_len);
+			    const struct qstr *name);
 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 			      struct btrfs_root *root,
 			      struct btrfs_path *path,
@@ -1648,10 +1646,10 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry);
 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index);
 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		       struct btrfs_inode *dir, struct btrfs_inode *inode,
-		       const char *name, int name_len);
+		       const struct qstr *name);
 int btrfs_add_link(struct btrfs_trans_handle *trans,
 		   struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
-		   const char *name, int name_len, int add_backref, u64 index);
+		   const struct qstr *name, int add_backref, u64 index);
 int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry);
 int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
 			 int front);
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;
 	}
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index b8dbabfa8b31..577e39cfc411 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -14,8 +14,8 @@
 #include "accessors.h"
 
 struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
-						   int slot, const char *name,
-						   int name_len)
+						   int slot,
+						   const struct qstr *name)
 {
 	struct btrfs_inode_ref *ref;
 	unsigned long ptr;
@@ -31,9 +31,10 @@ struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
 		len = btrfs_inode_ref_name_len(leaf, ref);
 		name_ptr = (unsigned long)(ref + 1);
 		cur_offset += len + sizeof(*ref);
-		if (len != name_len)
+		if (len != name->len)
 			continue;
-		if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
+		if (memcmp_extent_buffer(leaf, name->name, name_ptr,
+					 name->len) == 0)
 			return ref;
 	}
 	return NULL;
@@ -41,7 +42,7 @@ struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
 
 struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
 		struct extent_buffer *leaf, int slot, u64 ref_objectid,
-		const char *name, int name_len)
+		const struct qstr *name)
 {
 	struct btrfs_inode_extref *extref;
 	unsigned long ptr;
@@ -64,9 +65,10 @@ struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
 		name_ptr = (unsigned long)(&extref->name);
 		ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
 
-		if (ref_name_len == name_len &&
+		if (ref_name_len == name->len &&
 		    btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
-		    (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0))
+		    (memcmp_extent_buffer(leaf, name->name, name_ptr,
+					  name->len) == 0))
 			return extref;
 
 		cur_offset += ref_name_len + sizeof(*extref);
@@ -79,7 +81,7 @@ struct btrfs_inode_extref *
 btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 			  struct btrfs_root *root,
 			  struct btrfs_path *path,
-			  const char *name, int name_len,
+			  const struct qstr *name,
 			  u64 inode_objectid, u64 ref_objectid, int ins_len,
 			  int cow)
 {
@@ -88,7 +90,7 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 
 	key.objectid = inode_objectid;
 	key.type = BTRFS_INODE_EXTREF_KEY;
-	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
 
 	ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 	if (ret < 0)
@@ -96,13 +98,13 @@ btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
 	if (ret > 0)
 		return NULL;
 	return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
-					      ref_objectid, name, name_len);
+					      ref_objectid, name);
 
 }
 
 static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
 				  struct btrfs_root *root,
-				  const char *name, int name_len,
+				  const struct qstr *name,
 				  u64 inode_objectid, u64 ref_objectid,
 				  u64 *index)
 {
@@ -111,14 +113,14 @@ static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
 	struct btrfs_inode_extref *extref;
 	struct extent_buffer *leaf;
 	int ret;
-	int del_len = name_len + sizeof(*extref);
+	int del_len = name->len + sizeof(*extref);
 	unsigned long ptr;
 	unsigned long item_start;
 	u32 item_size;
 
 	key.objectid = inode_objectid;
 	key.type = BTRFS_INODE_EXTREF_KEY;
-	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -136,7 +138,7 @@ static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
 	 * readonly.
 	 */
 	extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0],
-						ref_objectid, name, name_len);
+						ref_objectid, name);
 	if (!extref) {
 		btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL);
 		ret = -EROFS;
@@ -172,8 +174,7 @@ out:
 }
 
 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
-			struct btrfs_root *root,
-			const char *name, int name_len,
+			struct btrfs_root *root, const struct qstr *name,
 			u64 inode_objectid, u64 ref_objectid, u64 *index)
 {
 	struct btrfs_path *path;
@@ -186,7 +187,7 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
 	u32 sub_item_len;
 	int ret;
 	int search_ext_refs = 0;
-	int del_len = name_len + sizeof(*ref);
+	int del_len = name->len + sizeof(*ref);
 
 	key.objectid = inode_objectid;
 	key.offset = ref_objectid;
@@ -205,8 +206,7 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
 		goto out;
 	}
 
-	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name,
-					 name_len);
+	ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name);
 	if (!ref) {
 		ret = -ENOENT;
 		search_ext_refs = 1;
@@ -223,7 +223,7 @@ int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
 		goto out;
 	}
 	ptr = (unsigned long)ref;
-	sub_item_len = name_len + sizeof(*ref);
+	sub_item_len = name->len + sizeof(*ref);
 	item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
 	memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
 			      item_size - (ptr + sub_item_len - item_start));
@@ -237,7 +237,7 @@ out:
 		 * name in our ref array. Find and remove the extended
 		 * inode ref then.
 		 */
-		return btrfs_del_inode_extref(trans, root, name, name_len,
+		return btrfs_del_inode_extref(trans, root, name,
 					      inode_objectid, ref_objectid, index);
 	}
 
@@ -251,12 +251,13 @@ out:
  */
 static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 				     struct btrfs_root *root,
-				     const char *name, int name_len,
-				     u64 inode_objectid, u64 ref_objectid, u64 index)
+				     const struct qstr *name,
+				     u64 inode_objectid, u64 ref_objectid,
+				     u64 index)
 {
 	struct btrfs_inode_extref *extref;
 	int ret;
-	int ins_len = name_len + sizeof(*extref);
+	int ins_len = name->len + sizeof(*extref);
 	unsigned long ptr;
 	struct btrfs_path *path;
 	struct btrfs_key key;
@@ -264,7 +265,7 @@ static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 
 	key.objectid = inode_objectid;
 	key.type = BTRFS_INODE_EXTREF_KEY;
-	key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+	key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len);
 
 	path = btrfs_alloc_path();
 	if (!path)
@@ -276,7 +277,7 @@ static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 		if (btrfs_find_name_in_ext_backref(path->nodes[0],
 						   path->slots[0],
 						   ref_objectid,
-						   name, name_len))
+						   name))
 			goto out;
 
 		btrfs_extend_item(path, ins_len);
@@ -290,12 +291,12 @@ static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
 	ptr += btrfs_item_size(leaf, path->slots[0]) - ins_len;
 	extref = (struct btrfs_inode_extref *)ptr;
 
-	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
+	btrfs_set_inode_extref_name_len(path->nodes[0], extref, name->len);
 	btrfs_set_inode_extref_index(path->nodes[0], extref, index);
 	btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
 
 	ptr = (unsigned long)&extref->name;
-	write_extent_buffer(path->nodes[0], name, ptr, name_len);
+	write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 
 out:
@@ -305,8 +306,7 @@ out:
 
 /* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
 int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root,
-			   const char *name, int name_len,
+			   struct btrfs_root *root, const struct qstr *name,
 			   u64 inode_objectid, u64 ref_objectid, u64 index)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -315,7 +315,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 	struct btrfs_inode_ref *ref;
 	unsigned long ptr;
 	int ret;
-	int ins_len = name_len + sizeof(*ref);
+	int ins_len = name->len + sizeof(*ref);
 
 	key.objectid = inode_objectid;
 	key.offset = ref_objectid;
@@ -331,7 +331,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 	if (ret == -EEXIST) {
 		u32 old_size;
 		ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
-						 name, name_len);
+						 name);
 		if (ref)
 			goto out;
 
@@ -340,7 +340,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
 				     struct btrfs_inode_ref);
 		ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
-		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
 		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
 		ptr = (unsigned long)(ref + 1);
 		ret = 0;
@@ -348,7 +348,7 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 		if (ret == -EOVERFLOW) {
 			if (btrfs_find_name_in_backref(path->nodes[0],
 						       path->slots[0],
-						       name, name_len))
+						       name))
 				ret = -EEXIST;
 			else
 				ret = -EMLINK;
@@ -357,11 +357,11 @@ int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
 	} else {
 		ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
 				     struct btrfs_inode_ref);
-		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+		btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len);
 		btrfs_set_inode_ref_index(path->nodes[0], ref, index);
 		ptr = (unsigned long)(ref + 1);
 	}
-	write_extent_buffer(path->nodes[0], name, ptr, name_len);
+	write_extent_buffer(path->nodes[0], name->name, ptr, name->len);
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 
 out:
@@ -374,7 +374,6 @@ out:
 		if (btrfs_super_incompat_flags(disk_super)
 		    & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
 			ret = btrfs_insert_inode_extref(trans, root, name,
-							name_len,
 							inode_objectid,
 							ref_objectid, index);
 	}
diff --git a/fs/btrfs/inode-item.h b/fs/btrfs/inode-item.h
index a8fc16d0147f..3c657c670cfd 100644
--- a/fs/btrfs/inode-item.h
+++ b/fs/btrfs/inode-item.h
@@ -64,33 +64,31 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
 			       struct btrfs_root *root,
 			       struct btrfs_truncate_control *control);
 int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root,
-			   const char *name, int name_len,
+			   struct btrfs_root *root, const struct qstr *name,
 			   u64 inode_objectid, u64 ref_objectid, u64 index);
 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root,
-			   const char *name, int name_len,
-			   u64 inode_objectid, u64 ref_objectid, u64 *index);
+			struct btrfs_root *root, const struct qstr *name,
+			u64 inode_objectid, u64 ref_objectid, u64 *index);
 int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     struct btrfs_path *path, u64 objectid);
-int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
-		       *root, struct btrfs_path *path,
+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 char *name, int name_len,
+			  const struct qstr *name,
 			  u64 inode_objectid, u64 ref_objectid, int ins_len,
 			  int cow);
 
 struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf,
-						   int slot, const char *name,
-						   int name_len);
+						   int slot,
+						   const struct qstr *name);
 struct btrfs_inode_extref *btrfs_find_name_in_ext_backref(
 		struct extent_buffer *leaf, int slot, u64 ref_objectid,
-		const char *name, int name_len);
+		const struct qstr *name);
 
 #endif
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index cb2a6d7f6252..3162d8f0aaf8 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3641,7 +3641,7 @@ void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
 	spin_unlock(&fs_info->delayed_iput_lock);
 }
 
-/**
+/*
  * Wait for flushing all delayed iputs
  *
  * @fs_info:  the filesystem
@@ -4286,7 +4286,7 @@ int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 				struct btrfs_inode *dir,
 				struct btrfs_inode *inode,
-				const char *name, int name_len,
+				const struct qstr *name,
 				struct btrfs_rename_ctx *rename_ctx)
 {
 	struct btrfs_root *root = dir->root;
@@ -4304,8 +4304,7 @@ static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		goto out;
 	}
 
-	di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
-				    name, name_len, -1);
+	di = btrfs_lookup_dir_item(trans, root, path, dir_ino, name, -1);
 	if (IS_ERR_OR_NULL(di)) {
 		ret = di ? PTR_ERR(di) : -ENOENT;
 		goto err;
@@ -4333,12 +4332,11 @@ static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		}
 	}
 
-	ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
-				  dir_ino, &index);
+	ret = btrfs_del_inode_ref(trans, root, name, ino, dir_ino, &index);
 	if (ret) {
 		btrfs_info(fs_info,
 			"failed to delete reference to %.*s, inode %llu parent %llu",
-			name_len, name, ino, dir_ino);
+			name->len, name->name, ino, dir_ino);
 		btrfs_abort_transaction(trans, ret);
 		goto err;
 	}
@@ -4359,10 +4357,8 @@ skip_backref:
 	 * operations on the log tree, increasing latency for applications.
 	 */
 	if (!rename_ctx) {
-		btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
-					   dir_ino);
-		btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
-					     index);
+		btrfs_del_inode_ref_in_log(trans, root, name, inode, dir_ino);
+		btrfs_del_dir_entries_in_log(trans, root, name, dir, index);
 	}
 
 	/*
@@ -4380,7 +4376,7 @@ err:
 	if (ret)
 		goto out;
 
-	btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
+	btrfs_i_size_write(dir, dir->vfs_inode.i_size - name->len * 2);
 	inode_inc_iversion(&inode->vfs_inode);
 	inode_inc_iversion(&dir->vfs_inode);
 	inode->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
@@ -4393,10 +4389,11 @@ out:
 
 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
 		       struct btrfs_inode *dir, struct btrfs_inode *inode,
-		       const char *name, int name_len)
+		       const struct qstr *name)
 {
 	int ret;
-	ret = __btrfs_unlink_inode(trans, dir, inode, name, name_len, NULL);
+
+	ret = __btrfs_unlink_inode(trans, dir, inode, name, NULL);
 	if (!ret) {
 		drop_nlink(&inode->vfs_inode);
 		ret = btrfs_update_inode(trans, inode->root, inode);
@@ -4440,9 +4437,8 @@ static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
 	btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
 			0);
 
-	ret = btrfs_unlink_inode(trans, BTRFS_I(dir),
-			BTRFS_I(d_inode(dentry)), dentry->d_name.name,
-			dentry->d_name.len);
+	ret = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
+				 &dentry->d_name);
 	if (ret)
 		goto out;
 
@@ -4467,8 +4463,7 @@ static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
 	struct extent_buffer *leaf;
 	struct btrfs_dir_item *di;
 	struct btrfs_key key;
-	const char *name = dentry->d_name.name;
-	int name_len = dentry->d_name.len;
+	const struct qstr *name = &dentry->d_name;
 	u64 index;
 	int ret;
 	u64 objectid;
@@ -4487,8 +4482,7 @@ static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
 	if (!path)
 		return -ENOMEM;
 
-	di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
-				   name, name_len, -1);
+	di = btrfs_lookup_dir_item(trans, root, path, dir_ino, name, -1);
 	if (IS_ERR_OR_NULL(di)) {
 		ret = di ? PTR_ERR(di) : -ENOENT;
 		goto out;
@@ -4514,8 +4508,7 @@ static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
 	 * call btrfs_del_root_ref, and it _shouldn't_ fail.
 	 */
 	if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
-		di = btrfs_search_dir_index_item(root, path, dir_ino,
-						 name, name_len);
+		di = btrfs_search_dir_index_item(root, path, dir_ino, name);
 		if (IS_ERR_OR_NULL(di)) {
 			if (!di)
 				ret = -ENOENT;
@@ -4532,7 +4525,7 @@ static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
 	} else {
 		ret = btrfs_del_root_ref(trans, objectid,
 					 root->root_key.objectid, dir_ino,
-					 &index, name, name_len);
+					 &index, name);
 		if (ret) {
 			btrfs_abort_transaction(trans, ret);
 			goto out;
@@ -4545,7 +4538,7 @@ static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
 		goto out;
 	}
 
-	btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
+	btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name->len * 2);
 	inode_inc_iversion(dir);
 	dir->i_mtime = current_time(dir);
 	dir->i_ctime = dir->i_mtime;
@@ -4567,6 +4560,7 @@ static noinline int may_destroy_subvol(struct btrfs_root *root)
 	struct btrfs_path *path;
 	struct btrfs_dir_item *di;
 	struct btrfs_key key;
+	struct qstr name = QSTR_INIT("default", 7);
 	u64 dir_id;
 	int ret;
 
@@ -4577,7 +4571,7 @@ static noinline int may_destroy_subvol(struct btrfs_root *root)
 	/* Make sure this root isn't set as the default subvol */
 	dir_id = btrfs_super_root_dir(fs_info->super_copy);
 	di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
-				   dir_id, "default", 7, 0);
+				   dir_id, &name, 0);
 	if (di && !IS_ERR(di)) {
 		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
 		if (key.objectid == root->root_key.objectid) {
@@ -4844,9 +4838,8 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
 	last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
 
 	/* now the directory is empty */
-	err = btrfs_unlink_inode(trans, BTRFS_I(dir),
-			BTRFS_I(d_inode(dentry)), dentry->d_name.name,
-			dentry->d_name.len);
+	err = btrfs_unlink_inode(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
+				 &dentry->d_name);
 	if (!err) {
 		btrfs_i_size_write(BTRFS_I(inode), 0);
 		/*
@@ -5538,8 +5531,7 @@ no_delete:
 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
 			       struct btrfs_key *location, u8 *type)
 {
-	const char *name = dentry->d_name.name;
-	int namelen = dentry->d_name.len;
+	const struct qstr *name = &dentry->d_name;
 	struct btrfs_dir_item *di;
 	struct btrfs_path *path;
 	struct btrfs_root *root = BTRFS_I(dir)->root;
@@ -5550,7 +5542,7 @@ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
 		return -ENOMEM;
 
 	di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
-			name, namelen, 0);
+				   name, 0);
 	if (IS_ERR_OR_NULL(di)) {
 		ret = di ? PTR_ERR(di) : -ENOENT;
 		goto out;
@@ -5562,7 +5554,7 @@ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
 		ret = -EUCLEAN;
 		btrfs_warn(root->fs_info,
 "%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
-			   __func__, name, btrfs_ino(BTRFS_I(dir)),
+			   __func__, name->name, btrfs_ino(BTRFS_I(dir)),
 			   location->objectid, location->type, location->offset);
 	}
 	if (!ret)
@@ -6321,8 +6313,7 @@ int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
 {
 	struct inode *dir = args->dir;
 	struct inode *inode = args->inode;
-	const char *name = args->orphan ? NULL : args->dentry->d_name.name;
-	int name_len = args->orphan ? 0 : args->dentry->d_name.len;
+	const struct qstr *name = args->orphan ? NULL : &args->dentry->d_name;
 	struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
 	struct btrfs_root *root;
 	struct btrfs_inode_item *inode_item;
@@ -6423,7 +6414,7 @@ int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
 			sizes[1] = 2 + sizeof(*ref);
 		} else {
 			key[1].offset = btrfs_ino(BTRFS_I(dir));
-			sizes[1] = name_len + sizeof(*ref);
+			sizes[1] = name->len + sizeof(*ref);
 		}
 	}
 
@@ -6462,10 +6453,12 @@ int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
 			btrfs_set_inode_ref_index(path->nodes[0], ref, 0);
 			write_extent_buffer(path->nodes[0], "..", ptr, 2);
 		} else {
-			btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+			btrfs_set_inode_ref_name_len(path->nodes[0], ref,
+						     name->len);
 			btrfs_set_inode_ref_index(path->nodes[0], ref,
 						  BTRFS_I(inode)->dir_index);
-			write_extent_buffer(path->nodes[0], name, ptr, name_len);
+			write_extent_buffer(path->nodes[0], name->name, ptr,
+					    name->len);
 		}
 	}
 
@@ -6526,7 +6519,7 @@ int btrfs_create_new_inode(struct btrfs_trans_handle *trans,
 		ret = btrfs_orphan_add(trans, BTRFS_I(inode));
 	} else {
 		ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
-				     name_len, 0, BTRFS_I(inode)->dir_index);
+				     0, BTRFS_I(inode)->dir_index);
 	}
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
@@ -6555,7 +6548,7 @@ out:
  */
 int btrfs_add_link(struct btrfs_trans_handle *trans,
 		   struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
-		   const char *name, int name_len, int add_backref, u64 index)
+		   const struct qstr *name, int add_backref, u64 index)
 {
 	int ret = 0;
 	struct btrfs_key key;
@@ -6574,17 +6567,17 @@ int btrfs_add_link(struct btrfs_trans_handle *trans,
 	if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
 		ret = btrfs_add_root_ref(trans, key.objectid,
 					 root->root_key.objectid, parent_ino,
-					 index, name, name_len);
+					 index, name);
 	} else if (add_backref) {
-		ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
-					     parent_ino, index);
+		ret = btrfs_insert_inode_ref(trans, root, name,
+					     ino, parent_ino, index);
 	}
 
 	/* Nothing to clean up yet */
 	if (ret)
 		return ret;
 
-	ret = btrfs_insert_dir_item(trans, name, name_len, parent_inode, &key,
+	ret = btrfs_insert_dir_item(trans, name, parent_inode, &key,
 				    btrfs_inode_type(&inode->vfs_inode), index);
 	if (ret == -EEXIST || ret == -EOVERFLOW)
 		goto fail_dir_item;
@@ -6594,7 +6587,7 @@ int btrfs_add_link(struct btrfs_trans_handle *trans,
 	}
 
 	btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
-			   name_len * 2);
+			   name->len * 2);
 	inode_inc_iversion(&parent_inode->vfs_inode);
 	/*
 	 * If we are replaying a log tree, we do not want to update the mtime
@@ -6619,15 +6612,15 @@ fail_dir_item:
 		int err;
 		err = btrfs_del_root_ref(trans, key.objectid,
 					 root->root_key.objectid, parent_ino,
-					 &local_index, name, name_len);
+					 &local_index, name);
 		if (err)
 			btrfs_abort_transaction(trans, err);
 	} else if (add_backref) {
 		u64 local_index;
 		int err;
 
-		err = btrfs_del_inode_ref(trans, root, name, name_len,
-					  ino, parent_ino, &local_index);
+		err = btrfs_del_inode_ref(trans, root, name, ino, parent_ino,
+					  &local_index);
 		if (err)
 			btrfs_abort_transaction(trans, err);
 	}
@@ -6747,7 +6740,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
 	set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
 
 	err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
-			     dentry->d_name.name, dentry->d_name.len, 1, index);
+			     &dentry->d_name, 1, index);
 
 	if (err) {
 		drop_inode = 1;
@@ -9088,9 +9081,7 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 		/* force full log commit if subvolume involved. */
 		btrfs_set_log_full_commit(trans);
 	} else {
-		ret = btrfs_insert_inode_ref(trans, dest,
-					     new_dentry->d_name.name,
-					     new_dentry->d_name.len,
+		ret = btrfs_insert_inode_ref(trans, dest, &new_dentry->d_name,
 					     old_ino,
 					     btrfs_ino(BTRFS_I(new_dir)),
 					     old_idx);
@@ -9104,9 +9095,7 @@ static int btrfs_rename_exchang