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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
This commit is contained in:
Christian Brauner 2021-01-21 14:19:52 +01:00
parent fbdc2f6c40
commit 5b490500f9
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
1 changed files with 24 additions and 16 deletions

View File

@ -3465,6 +3465,28 @@ out_type:
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: