Unverified Commit 9eccd12c authored by Christian Brauner's avatar Christian Brauner
Browse files

fcntl: handle idmapped mounts 

Enable the setfl() helper to handle idmapped mounts by passing down the
mount's user namespace. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/20210121131959.646623-20-christian.brauner@ubuntu.com


Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJames Morris <jamorris@linux.microsoft.com>
Signed-off-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
parent d06c26f1

fs/fcntl.c

+2 −1
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/user_namespace.h>

#include <linux/memfd.h>

#include <linux/compat.h>

#include <linux/mount.h>



#include <linux/poll.h>

#include <asm/siginfo.h>
@@ -46,7 +47,7 @@ static int setfl(int fd, struct file * filp, unsigned long arg) 


	/* O_NOATIME can only be set by the owner or superuser */

	if ((arg & O_NOATIME) && !(filp->f_flags & O_NOATIME))

		if (!inode_owner_or_capable(&init_user_ns, inode))

		if (!inode_owner_or_capable(file_mnt_user_ns(filp), inode))

			return -EPERM;



	/* required for strict SunOS emulation */