libmount: don't call hooks after mount.<type> helper

In case more filesystems are specified (or when libmount follows
/{etc,proc}/filesystems) then the library may try to use and
initialize the new API because for some filesystems, we need
exec(/sbin/mount.<type>) and for another fsopen().

The hooks that use the API have to smart and detect that the mount
operation was done in external /sbin/mount.<type> helper. And in this
case, the new API file descriptors must be ignored.

The exception is propagation flags, mount(8) can set the flags after
exec(/sbin/mount.<type>), for example, "mount -t ntfs --make-private".

Fixes: https://github.com/util-linux/util-linux/issues/2267
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/libmount/src/context_mount.c b/libmount/src/context_mount.c
index cbb4f1fdfa26f6fb28dd84bf3460657ae713a28a..40f9ed07337ec5eb3b79211c65ca495b0281a271 100644 (file)
--- a/libmount/src/context_mount.c
+++ b/libmount/src/context_mount.c
@@ -508,6 +508,8 @@ static int do_mount(struct libmnt_context *cxt, const char *try_type)
        assert(cxt->fs);
        assert((cxt->flags & MNT_FL_MOUNTFLAGS_MERGED));
 
+       mnt_context_reset_status(cxt);
+
        if (try_type) {
                rc = mnt_context_prepare_helper(cxt, "mount", try_type);
                if (rc)

diff --git a/libmount/src/hook_mount.c b/libmount/src/hook_mount.c
index 924c71444828f3ac11e85ed8c9606c7723756695..91483afa68f6caadb8b648e1db2139b4c7e325ff 100644 (file)
--- a/libmount/src/hook_mount.c
+++ b/libmount/src/hook_mount.c
@@ -239,6 +239,10 @@ static int hook_create_mount(struct libmnt_context *cxt,
        int rc = 0;
 
        assert(cxt);
+
+       if (mnt_context_helper_executed(cxt))
+               return 0;
+
        assert(cxt->fs);
 
        api = get_sysapi(cxt);
@@ -309,6 +313,9 @@ static int hook_reconfigure_mount(struct libmnt_context *cxt,
 
        assert(cxt);
 
+       if (mnt_context_helper_executed(cxt))
+               return 0;
+
        api = get_sysapi(cxt);
        assert(api);
        assert(api->fd_tree >= 0);
@@ -379,6 +386,9 @@ static int hook_set_vfsflags(struct libmnt_context *cxt,
        uint64_t set = 0, clr = 0;
        int rc = 0;
 
+       if (mnt_context_helper_executed(cxt))
+               return 0;
+
        DBG(HOOK, ul_debugobj(hs, "setting VFS flags"));
 
        ol = mnt_context_get_optlist(cxt);
@@ -471,6 +481,9 @@ static int hook_attach_target(struct libmnt_context *cxt,
        const char *target;
        int rc = 0;
 
+       if (mnt_context_helper_executed(cxt))
+               return 0;
+
        target = mnt_fs_get_target(cxt->fs);
        if (!target)
                return -EINVAL;