diff --git a/drivers/block/loop.c b/drivers/block/loop.c index e9d594fd12cbee408251c4ead03d1b71183ff7ae..54046e51160aef28e3ee733797fa453a0403a02a 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -976,8 +976,21 @@ static int loop_clr_fd(struct loop_device *lo) if (lo->lo_state != Lo_bound) return -ENXIO; - if (lo->lo_refcnt > 1) /* we needed one fd for the ioctl */ - return -EBUSY; + /* + * If we've explicitly asked to tear down the loop device, + * and it has an elevated reference count, set it for auto-teardown when + * the last reference goes away. This stops $!~#$@ udev from + * preventing teardown because it decided that it needs to run blkid on + * the loopback device whenever they appear. xfstests is notorious for + * failing tests because blkid via udev races with a losetup + * /do something like mkfs/losetup -d causing the losetup -d + * command to fail with EBUSY. + */ + if (lo->lo_refcnt > 1) { + lo->lo_flags |= LO_FLAGS_AUTOCLEAR; + mutex_unlock(&lo->lo_ctl_mutex); + return 0; + } if (filp == NULL) return -EINVAL;