drbd: Fix a potential race that could case data inconsistency
authorPhilipp Reisner <philipp.reisner@linbit.com>
Mon, 16 Jan 2012 11:14:01 +0000 (12:14 +0100)
committerPhilipp Reisner <philipp.reisner@linbit.com>
Wed, 9 May 2012 13:16:34 +0000 (15:16 +0200)
commitfc28845bc005995b41ae8c83c7922d088f0ad228
treecb5f28c4c0cfb06f46b9e1b0d7e7efcdfc132f90
parent031a7c173ffda664ac5551bd13c313e513dd87a7
drbd: Fix a potential race that could case data inconsistency

When we have a write request and a state change C_WF_BITMAP_S -> C_SYNC_SOURCE
at the same time, and it happens that the line

remote = remote && drbd_should_do_remote(s);

stills sees C_WF_BITMAP_S, and

send_oos = rw == WRITE && drbd_should_send_oos(s);

already sees C_SYNC_SOURCE both are 0.

This causes the write to not be mirrored, but marked as out-of-sync on the
Sync_Source node.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
drivers/block/drbd/drbd_req.c