Unverified Commit 3dd4624f authored by Christian Brauner's avatar Christian Brauner
Browse files

udf: store cookie in private data 

Store the cookie to detect concurrent seeks on directories in
file->private_data.

Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-15-6d3e4816aa7b@kernel.org


Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent b4dba2ef

fs/udf/dir.c

+25 −3
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ static int udf_readdir(struct file *file, struct dir_context *ctx) 
	 * identifying beginning of dir entry (names are under user control),

	 * we need to scan the directory from the beginning.

	 */

	if (!inode_eq_iversion(dir, file->f_version)) {

	if (!inode_eq_iversion(dir, *(u64 *)file->private_data)) {

		emit_pos = nf_pos;

		nf_pos = 0;

	} else {
@@ -122,15 +122,37 @@ static int udf_readdir(struct file *file, struct dir_context *ctx) 
	udf_fiiter_release(&iter);

out:

	if (pos_valid)

		file->f_version = inode_query_iversion(dir);

		*(u64 *)file->private_data = inode_query_iversion(dir);

	kfree(fname);



	return ret;

}



static int udf_dir_open(struct inode *inode, struct file *file)

{

	file->private_data = kzalloc(sizeof(u64), GFP_KERNEL);

	if (!file->private_data)

		return -ENOMEM;

	return 0;

}



static int udf_dir_release(struct inode *inode, struct file *file)

{

	kfree(file->private_data);

	return 0;

}



static loff_t udf_dir_llseek(struct file *file, loff_t offset, int whence)

{

	return generic_llseek_cookie(file, offset, whence,

				     (u64 *)file->private_data);

}



/* readdir and lookup functions */

const struct file_operations udf_dir_operations = {

	.llseek			= generic_file_llseek,

	.open			= udf_dir_open,

	.release		= udf_dir_release,

	.llseek			= udf_dir_llseek,

	.read			= generic_read_dir,

	.iterate_shared		= udf_readdir,

	.unlocked_ioctl		= udf_ioctl,