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, 54 insertions, 76 deletions

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_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, root,
-					     old_dentry->d_name.name,
-					     old_dentry->d_name.len,
+		ret = btrfs_insert_inode_ref(trans, root, &old_dentry->d_name,
 					     new_ino,
 					     btrfs_ino(BTRFS_I(old_dir)),
 					     new_idx);
@@ -9142,8 +9131,7 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 	} else { /* src is an inode */
 		ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
 					   BTRFS_I(old_dentry->d_inode),
-					   old_dentry->d_name.name,
-					   old_dentry->d_name.len,
+					   &old_dentry->d_name,
 					   &old_rename_ctx);
 		if (!ret)
 			ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
@@ -9159,8 +9147,7 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 	} else { /* dest is an inode */
 		ret = __btrfs_unlink_inode(trans, BTRFS_I(new_dir),
 					   BTRFS_I(new_dentry->d_inode),
-					   new_dentry->d_name.name,
-					   new_dentry->d_name.len,
+					   &new_dentry->d_name,
 					   &new_rename_ctx);
 		if (!ret)
 			ret = btrfs_update_inode(trans, dest, BTRFS_I(new_inode));
@@ -9171,16 +9158,14 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 	}
 
 	ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
-			     new_dentry->d_name.name,
-			     new_dentry->d_name.len, 0, old_idx);
+			     &new_dentry->d_name, 0, old_idx);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		goto out_fail;
 	}
 
 	ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
-			     old_dentry->d_name.name,
-			     old_dentry->d_name.len, 0, new_idx);
+			     &old_dentry->d_name, 0, new_idx);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		goto out_fail;
@@ -9281,8 +9266,7 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 
 	/* check for collisions, even if the  name isn't there */
 	ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
-			     new_dentry->d_name.name,
-			     new_dentry->d_name.len);
+					     &new_dentry->d_name);
 
 	if (ret) {
 		if (ret == -EEXIST) {
@@ -9376,9 +9360,7 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 		/* 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)), index);
 		if (ret)
@@ -9402,10 +9384,8 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 		ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
 	} else {
 		ret = __btrfs_unlink_inode(trans, BTRFS_I(old_dir),
-					BTRFS_I(d_inode(old_dentry)),
-					old_dentry->d_name.name,
-					old_dentry->d_name.len,
-					&rename_ctx);
+					   BTRFS_I(d_inode(old_dentry)),
+					   &old_dentry->d_name, &rename_ctx);
 		if (!ret)
 			ret = btrfs_update_inode(trans, root, BTRFS_I(old_inode));
 	}
@@ -9424,8 +9404,7 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 		} else {
 			ret = btrfs_unlink_inode(trans, BTRFS_I(new_dir),
 						 BTRFS_I(d_inode(new_dentry)),
-						 new_dentry->d_name.name,
-						 new_dentry->d_name.len);
+						 &new_dentry->d_name);
 		}
 		if (!ret && new_inode->i_nlink == 0)
 			ret = btrfs_orphan_add(trans,
@@ -9437,8 +9416,7 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 	}
 
 	ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
-			     new_dentry->d_name.name,
-			     new_dentry->d_name.len, 0, index);
+			     &new_dentry->d_name, 0, index);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
 		goto out_fail;