From 4534b32c7394d9f5c9d49820f11b9f07fe41b079 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 22 Sep 2020 11:19:37 +0200 Subject: [PATCH] shutdown: fsync() before detaching loopback devices This is a follow-up for cae1e8fb88c5a6b0960a2d0be3df8755f0c78462: we also call the detach ioctls in the shutdown code, hence add the fsync()s there too, just to be safe. --- src/shutdown/umount.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/src/shutdown/umount.c b/src/shutdown/umount.c index 0eb694c1af9..307944c6575 100644 --- a/src/shutdown/umount.c +++ b/src/shutdown/umount.c @@ -387,8 +387,15 @@ static int delete_loopback(const char *device) { assert(device); fd = open(device, O_RDONLY|O_CLOEXEC); - if (fd < 0) + if (fd < 0) { + log_debug_errno(errno, "Failed to open loopback device %s: %m", device); return errno == ENOENT ? 0 : -errno; + } + + /* Loopback block devices don't sync in-flight blocks when we clear the fd, hence sync explicitly + * first */ + if (fsync(fd) < 0) + log_debug_errno(errno, "Failed to sync loop block device %s, ignoring: %m", device); if (ioctl(fd, LOOP_CLR_FD, 0) < 0) { if (errno == ENXIO) /* Nothing bound, didn't do anything */ -- 2.47.3