Unverified Commit 5b490500 authored by Christian Brauner's avatar Christian Brauner
Browse files

fs: add attr_flags_to_mnt_flags helper 

Add a simple helper to translate uapi MOUNT_ATTR_* flags to MNT_* flags
which we will use in follow-up patches too.

Link: https://lore.kernel.org/r/20210121131959.646623-34-christian.brauner@ubuntu.com


Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Suggested-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
parent fbdc2f6c

fs/namespace.c

+24 −16
Original line number Diff line number Diff line
@@ -3465,6 +3465,28 @@ SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name, 
	return ret;

}



#define FSMOUNT_VALID_FLAGS \

	(MOUNT_ATTR_RDONLY | MOUNT_ATTR_NOSUID | MOUNT_ATTR_NODEV | \

	 MOUNT_ATTR_NOEXEC | MOUNT_ATTR__ATIME | MOUNT_ATTR_NODIRATIME)



static unsigned int attr_flags_to_mnt_flags(u64 attr_flags)

{

	unsigned int mnt_flags = 0;



	if (attr_flags & MOUNT_ATTR_RDONLY)

		mnt_flags |= MNT_READONLY;

	if (attr_flags & MOUNT_ATTR_NOSUID)

		mnt_flags |= MNT_NOSUID;

	if (attr_flags & MOUNT_ATTR_NODEV)

		mnt_flags |= MNT_NODEV;

	if (attr_flags & MOUNT_ATTR_NOEXEC)

		mnt_flags |= MNT_NOEXEC;

	if (attr_flags & MOUNT_ATTR_NODIRATIME)

		mnt_flags |= MNT_NODIRATIME;



	return mnt_flags;

}



/*

 * Create a kernel mount representation for a new, prepared superblock

 * (specified by fs_fd) and attach to an open_tree-like file descriptor.
@@ -3487,24 +3509,10 @@ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags, 
	if ((flags & ~(FSMOUNT_CLOEXEC)) != 0)

		return -EINVAL;



	if (attr_flags & ~(MOUNT_ATTR_RDONLY |

			   MOUNT_ATTR_NOSUID |

			   MOUNT_ATTR_NODEV |

			   MOUNT_ATTR_NOEXEC |

			   MOUNT_ATTR__ATIME |

			   MOUNT_ATTR_NODIRATIME))

	if (attr_flags & ~FSMOUNT_VALID_FLAGS)

		return -EINVAL;



	if (attr_flags & MOUNT_ATTR_RDONLY)

		mnt_flags |= MNT_READONLY;

	if (attr_flags & MOUNT_ATTR_NOSUID)

		mnt_flags |= MNT_NOSUID;

	if (attr_flags & MOUNT_ATTR_NODEV)

		mnt_flags |= MNT_NODEV;

	if (attr_flags & MOUNT_ATTR_NOEXEC)

		mnt_flags |= MNT_NOEXEC;

	if (attr_flags & MOUNT_ATTR_NODIRATIME)

		mnt_flags |= MNT_NODIRATIME;

	mnt_flags = attr_flags_to_mnt_flags(attr_flags);



	switch (attr_flags & MOUNT_ATTR__ATIME) {

	case MOUNT_ATTR_STRICTATIME: