virtio-fs: don't show mount options

Virtio-fs does not accept any mount options, so it's confusing and wrong to
show any in /proc/mounts.

Reported-by: Stefan Hajnoczi <stefanha@redhat.com> 
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

3 files changed, 9 insertions, 0 deletions

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 956aeaf961ae..d148188cfca4 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -479,6 +479,7 @@ struct fuse_fs_context {
         bool destroy:1;
         bool no_control:1;
         bool no_force_umount:1;
+        bool no_mount_options:1;
         unsigned int max_read;
         unsigned int blksize;
         const char *subtype;
@@ -713,6 +714,9 @@ struct fuse_conn {
         /** Do not allow MNT_FORCE umount */
         unsigned int no_force_umount:1;
 
+        /* Do not show mount options */
+        unsigned int no_mount_options:1;
+
         /** The number of requests waiting for completion */
         atomic_t num_waiting;
 
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index e040e2a2b621..16aec32f7f3d 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -558,6 +558,9 @@ static int fuse_show_options(struct seq_file *m, struct dentry *root)
         struct super_block *sb = root->d_sb;
         struct fuse_conn *fc = get_fuse_conn_super(sb);
 
+        if (fc->no_mount_options)
+                return 0;
+
         seq_printf(m, ",user_id=%u", from_kuid_munged(fc->user_ns, fc->user_id));
         seq_printf(m, ",group_id=%u", from_kgid_munged(fc->user_ns, fc->group_id));
         if (fc->default_permissions)
@@ -1180,6 +1183,7 @@ int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
         fc->destroy = ctx->destroy;
         fc->no_control = ctx->no_control;
         fc->no_force_umount = ctx->no_force_umount;
+        fc->no_mount_options = ctx->no_mount_options;
 
         err = -ENOMEM;
         root = fuse_get_root_inode(sb, ctx->rootmode);
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 6af3f131e468..e22a0c003c3d 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -992,6 +992,7 @@ static int virtio_fs_fill_super(struct super_block *sb)
                 .destroy = true,
                 .no_control = true,
                 .no_force_umount = true,
+                .no_mount_options = true,
         };
 
         mutex_lock(&virtio_fs_mutex);