Commit 3c203783 authored by Hyunchul Lee's avatar Hyunchul Lee Committed by Steve French
Browse files

cifsd: re-implement ksmbd_vfs_kern_path 



re-implement ksmbd_vfs_kern_path() to change
recursion to iteration.

Signed-off-by: default avatarHyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: default avatarNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 7c3d3e99

fs/cifsd/vfs.c

+61 −42
Original line number Diff line number Diff line
@@ -50,14 +50,6 @@ static char *extract_last_component(char *path) 
	return p;

}



static void rollback_path_modification(char *filename)

{

	if (filename) {

		filename--;

		*filename = '/';

	}

}



static void ksmbd_vfs_inherit_owner(struct ksmbd_work *work,

		struct inode *parent_inode, struct inode *inode)

{
@@ -1231,44 +1223,32 @@ static int __caseless_lookup(struct dir_context *ctx, const char *name, 


/**

 * ksmbd_vfs_lookup_in_dir() - lookup a file in a directory

 * @dirname:	directory name

 * @filename:	filename to lookup

 * @dir:	path info

 * @name:	filename to lookup

 * @namelen:	filename length

 *

 * Return:	0 on success, otherwise error

 */

static int ksmbd_vfs_lookup_in_dir(char *dirname, char *filename)

static int ksmbd_vfs_lookup_in_dir(struct path *dir, char *name, size_t namelen)

{

	struct path dir_path;

	int ret;

	struct file *dfilp;

	int flags = O_RDONLY | O_LARGEFILE;

	int dirnamelen = strlen(dirname);

	struct ksmbd_readdir_data readdir_data = {

		.ctx.actor	= __caseless_lookup,

		.private	= filename,

		.used		= strlen(filename),

		.private	= name,

		.used		= namelen,

		.dirent_count	= 0,

	};



	ret = ksmbd_vfs_kern_path(dirname, 0, &dir_path, true);

	if (ret)

		goto error;



	dfilp = dentry_open(&dir_path, flags, current_cred());

	if (IS_ERR(dfilp)) {

		path_put(&dir_path);

		ksmbd_err("cannot open directory %s\n", dirname);

		ret = -EINVAL;

		goto error;

	}

	dfilp = dentry_open(dir, flags, current_cred());

	if (IS_ERR(dfilp))

		return PTR_ERR(dfilp);



	ret = ksmbd_vfs_readdir(dfilp, &readdir_data);

	if (readdir_data.dirent_count > 0)

		ret = 0;



	fput(dfilp);

	path_put(&dir_path);

error:

	dirname[dirnamelen] = '/';

	return ret;

}
@@ -1284,30 +1264,69 @@ static int ksmbd_vfs_lookup_in_dir(char *dirname, char *filename) 
int ksmbd_vfs_kern_path(char *name, unsigned int flags, struct path *path,

		bool caseless)

{

	char *filename = NULL;

	int err;



	if (name[0] != '/')

		return -EINVAL;



	err = kern_path(name, flags, path);

	if (!err)

		return err;

		return 0;



	if (caseless) {

		filename = extract_last_component(name);

		if (!filename)

		char *filepath;

		struct path parent;

		size_t path_len, remain_len;



		filepath = kstrdup(name, GFP_KERNEL);

		if (!filepath)

			return -ENOMEM;



		path_len = strlen(filepath);

		remain_len = path_len - 1;



		err = kern_path("/", flags, &parent);

		if (err)

			goto out;



		/* root reached */

		if (strlen(name) == 0)

		while (d_can_lookup(parent.dentry)) {

			char *filename = filepath + path_len - remain_len;

			char *next = strchrnul(filename, '/');

			size_t filename_len = next - filename;

			bool is_last = !next[0];



			if (filename_len == 0)

				break;



			err = ksmbd_vfs_lookup_in_dir(&parent, filename,

						      filename_len);

			if (err) {

				path_put(&parent);

				goto out;

			}



			path_put(&parent);

			next[0] = '\0';



		err = ksmbd_vfs_lookup_in_dir(name, filename);

			err = kern_path(filepath, flags, &parent);

			if (err)

				goto out;

		err = kern_path(name, flags, path);



			if (is_last) {

				path->mnt = parent.mnt;

				path->dentry = parent.dentry;

				goto out;

			}



			next[0] = '/';

			remain_len -= filename_len + 1;

		}



		path_put(&parent);

		err = -EINVAL;

out:

	rollback_path_modification(filename);

		kfree(filepath);

	}

	return err;

}