linux_dsm_epyc7002/drivers/block/drbd
Lars Ellenberg 7fb907c15f drbd: panic on delayed completion of aborted requests
"aborting" requests, or force-detaching the disk, is intended for
completely blocked/hung local backing devices which do no longer
complete requests at all, not even do error completions.  In this
situation, usually a hard-reset and failover is the only way out.

By "aborting", basically faking a local error-completion,
we allow for a more graceful swichover by cleanly migrating services.
Still the affected node has to be rebooted "soon".

By completing these requests, we allow the upper layers to re-use
the associated data pages.

If later the local backing device "recovers", and now DMAs some data
from disk into the original request pages, in the best case it will
just put random data into unused pages; but typically it will corrupt
meanwhile completely unrelated data, causing all sorts of damage.

Which means delayed successful completion,
especially for READ requests,
is a reason to panic().

We assume that a delayed *error* completion is OK,
though we still will complain noisily about it.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-10-30 08:39:17 +01:00
..
drbd_actlog.c drbd: announce FLUSH/FUA capability to upper layers 2012-07-24 15:14:28 +02:00
drbd_bitmap.c drbd: Write all pages of the bitmap after an online resize 2012-08-16 17:17:35 +02:00
drbd_int.h drbd: Avoid NetworkFailure state during disconnect 2012-10-30 08:39:17 +01:00
drbd_main.c drbd: Avoid NetworkFailure state during disconnect 2012-10-30 08:39:17 +01:00
drbd_nl.c drbd: introduce stop-sector to online verify 2012-10-30 08:39:01 +01:00
drbd_proc.c drbd: introduce stop-sector to online verify 2012-10-30 08:39:01 +01:00
drbd_receiver.c drbd: Remove dead code 2012-10-30 08:39:17 +01:00
drbd_req.c drbd: Finish requests that completed while IO was frozen 2012-08-16 17:14:45 +02:00
drbd_req.h drbd: Immediately allow completion of IOs, that wait for IO completions on a failed disk 2012-05-09 10:16:04 +02:00
drbd_strings.c drbd: Rename enum drbd_state_ret_codes to enum drbd_state_rv 2011-03-10 11:36:18 +01:00
drbd_vli.h Fix common misspellings 2011-03-31 11:26:23 -03:00
drbd_worker.c drbd: panic on delayed completion of aborted requests 2012-10-30 08:39:17 +01:00
drbd_wrappers.h drbd: Get rid of unnecessary macros (2) 2011-03-10 11:36:15 +01:00
Kconfig drbd: Kconfig fix 2009-12-29 17:38:28 +01:00
Makefile drbd: remove tracing bits 2009-10-01 21:17:58 +02:00