Unverified Commit d0eab9fc authored by Jeff Layton's avatar Jeff Layton Committed by Christian Brauner
Browse files

filelock: lift the ban on directory leases in generic_setlease 



With the addition of the try_break_lease calls in directory changing
operations, allow generic_setlease to hand them out. Write leases on
directories are never allowed however, so continue to reject them.

For now, there is no API for requesting delegations from userland, so
ensure that userland is prevented from acquiring a lease on a directory.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarNeilBrown <neil@brown.name>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-13-52f3feebb2f2@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 92bf5357

fs/locks.c

+10 −2
Original line number Diff line number Diff line
@@ -1935,14 +1935,19 @@ static int generic_delete_lease(struct file *filp, void *owner) 
int generic_setlease(struct file *filp, int arg, struct file_lease **flp,

			void **priv)

{

	if (!S_ISREG(file_inode(filp)->i_mode))

	struct inode *inode = file_inode(filp);



	if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))

		return -EINVAL;



	switch (arg) {

	case F_UNLCK:

		return generic_delete_lease(filp, *priv);

	case F_RDLCK:

	case F_WRLCK:

		if (S_ISDIR(inode->i_mode))

			return -EINVAL;

		fallthrough;

	case F_RDLCK:

		if (!(*flp)->fl_lmops->lm_break) {

			WARN_ON_ONCE(1);

			return -ENOLCK;
@@ -2071,6 +2076,9 @@ static int do_fcntl_add_lease(unsigned int fd, struct file *filp, int arg) 
 */

int fcntl_setlease(unsigned int fd, struct file *filp, int arg)

{

	if (S_ISDIR(file_inode(filp)->i_mode))

		return -EINVAL;



	if (arg == F_UNLCK)

		return vfs_setlease(filp, F_UNLCK, NULL, (void **)&filp);

	return do_fcntl_add_lease(fd, filp, arg);