drbd: validate resync_after dependency on attach already
authorLars Ellenberg <lars.ellenberg@linbit.com>
Wed, 27 Mar 2013 13:08:43 +0000 (14:08 +0100)
committerJens Axboe <axboe@kernel.dk>
Thu, 28 Mar 2013 16:10:25 +0000 (10:10 -0600)
commita3f8f7dc7ad652cd84c12cb5efa0f7722dff4786
tree76bdcd59708d7441ce7fbc3906d030e34349093e
parent94ad0a101415978be04945b2787be1e8e8a874db
drbd: validate resync_after dependency on attach already

We validated resync_after dependencies, if changed via disk-options.
But we did not validate them when first created via attach.
We also did not check or cleanup dependencies that used to be correct,
but now point to meanwhile removed minor devices.

If the drbd_resync_after_valid() validation in disk-options tried to
follow a dependency chain in this way, this could lead to NULL pointer
dereference.

Validate resync_after settings in drbd_adm_attach() already, as well as
in drbd_adm_disk_opts(), and and only reject dependency loops.
Depending on non-existing disks is allowed and equivalent to no dependency.

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>
drivers/block/drbd/drbd_nl.c
drivers/block/drbd/drbd_worker.c