CHERRY-PICK: mount-encrypted: issue sync()s between umount stages
In an effort to reduce the chances of a kernel bug wrecking filesystems
during encrypted-stateful shutdown, add explicit sync() calls during
shutdown.
BUG=chrome-os-partner:17610
TEST=link build, shutdown with simulated panic in LOOP_CLR_FD results in
successful journal replays
BRANCH=None
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/43736
Reviewed-by: Grant Grundler <grundler@chromium.org>
Change-Id: Ifd2a5f70c325d0a24296fed5e8f303838e25c36c
(cherry picked from ToT commit e6cf2c21a1cd6fc46b6adcaadc865e2f8bd4874e)
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/43837
Reviewed-by: Luigi Semenzato <semenzato@chromium.org>
diff --git a/utility/mount-encrypted.c b/utility/mount-encrypted.c
index 98e63e7..9dbedc2 100644
--- a/utility/mount-encrypted.c
+++ b/utility/mount-encrypted.c
@@ -1063,6 +1063,12 @@
}
}
+ /*
+ * Force syncs to make sure we don't tickle racey/buggy kernel
+ * routines that might be causing crosbug.com/p/17610.
+ */
+ sync();
+
/* Optionally run fsck on the device after umount. */
if (getenv("MOUNT_ENCRYPTED_FSCK")) {
char *cmd;
@@ -1081,12 +1087,15 @@
INFO("Removing %s.", dmcrypt_dev);
if (!dm_teardown(dmcrypt_dev))
ERROR("dm_teardown(%s)", dmcrypt_dev);
+ sync();
INFO("Unlooping %s (named %s).", block_path, dmcrypt_name);
if (!loop_detach_name(dmcrypt_name)) {
ERROR("loop_detach_name(%s)", dmcrypt_name);
return EXIT_FAILURE;
}
+ sync();
+
return EXIT_SUCCESS;
}
