cifs: add "multiuser" mount option
This allows someone to declare a mount as a multiuser mount.
Multiuser mounts also imply "noperm" since we want to allow the server
to handle permission checking. It also (for now) requires Kerberos
authentication. Eventually, we could expand this to other authtypes, but
that requires a scheme to allow per-user credential stashing in some
form.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 3156a9d..e65f72d 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -100,6 +100,7 @@
bool nostrictsync:1; /* do not force expensive SMBflush on every sync */
bool fsc:1; /* enable fscache */
bool mfsymlinks:1; /* use Minshall+French Symlinks */
+ bool multiuser:1;
unsigned int rsize;
unsigned int wsize;
bool sockopt_tcp_nodelay:1;
@@ -1347,6 +1348,8 @@
vol->fsc = true;
} else if (strnicmp(data, "mfsymlinks", 10) == 0) {
vol->mfsymlinks = true;
+ } else if (strnicmp(data, "multiuser", 8) == 0) {
+ vol->multiuser = true;
} else
printk(KERN_WARNING "CIFS: Unknown mount option %s\n",
data);
@@ -1378,6 +1381,13 @@
return 1;
}
}
+
+ if (vol->multiuser && !(vol->secFlg & CIFSSEC_MAY_KRB5)) {
+ cERROR(1, "Multiuser mounts currently require krb5 "
+ "authentication!");
+ return 1;
+ }
+
if (vol->UNCip == NULL)
vol->UNCip = &vol->UNC[2];
@@ -2563,6 +2573,9 @@
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_DYNPERM;
if (pvolume_info->fsc)
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_FSCACHE;
+ if (pvolume_info->multiuser)
+ cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_MULTIUSER |
+ CIFS_MOUNT_NO_PERM);
if (pvolume_info->direct_io) {
cFYI(1, "mounting share using direct i/o");
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_DIRECT_IO;