fuse: allow skipping control interface and forced unmount

virtio-fs does not support aborting requests which are being
processed. That is requests which have been sent to fuse daemon on host.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

2 files changed, 14 insertions, 1 deletions

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 48d214df9172..fc89cb40e874 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -468,6 +468,8 @@ struct fuse_fs_context {
         bool default_permissions:1;
         bool allow_other:1;
         bool destroy:1;
+        bool no_control:1;
+        bool no_force_umount:1;
         unsigned int max_read;
         unsigned int blksize;
         const char *subtype;
@@ -696,6 +698,12 @@ struct fuse_conn {
         /* Delete dentries that have gone stale */
         unsigned int delete_stale:1;
 
+        /** Do not create entry in fusectl fs */
+        unsigned int no_control:1;
+
+        /** Do not allow MNT_FORCE umount */
+        unsigned int no_force_umount: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 cd6ffb3fe69e..10d193b24fb8 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -364,7 +364,10 @@ void fuse_unlock_inode(struct inode *inode, bool locked)
 
 static void fuse_umount_begin(struct super_block *sb)
 {
-        fuse_abort_conn(get_fuse_conn_super(sb));
+        struct fuse_conn *fc = get_fuse_conn_super(sb);
+
+        if (!fc->no_force_umount)
+                fuse_abort_conn(fc);
 }
 
 static void fuse_send_destroy(struct fuse_conn *fc)
@@ -1171,6 +1174,8 @@ int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx)
         fc->group_id = ctx->group_id;
         fc->max_read = max_t(unsigned, 4096, ctx->max_read);
         fc->destroy = ctx->destroy;
+        fc->no_control = ctx->no_control;
+        fc->no_force_umount = ctx->no_force_umount;
 
         err = -ENOMEM;
         root = fuse_get_root_inode(sb, ctx->rootmode);