]> git.openfabrics.org - ~shefty/rdma-dev.git/commit
dm: fix deadlock with request based dm and queue request_fn recursion
authorJens Axboe <axboe@kernel.dk>
Tue, 6 Nov 2012 11:24:26 +0000 (12:24 +0100)
committerJens Axboe <axboe@kernel.dk>
Fri, 23 Nov 2012 13:32:54 +0000 (14:32 +0100)
commita8c32a5c98943d370ea606a2e7dc04717eb92206
tree234dc265f7af235e1360da7d6e862abacd2f32c0
parenteac7cc52c6b410e542af431b2ee93f3d7dbfb6af
dm: fix deadlock with request based dm and queue request_fn recursion

Request based dm attempts to re-run the request queue off the
request completion path. If used with a driver that potentially does
end_io from its request_fn, we could deadlock trying to recurse
back into request dispatch. Fix this by punting the request queue
run to kblockd.

Tested to fix a quickly reproducible deadlock in such a scenario.

Cc: stable@kernel.org
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/md/dm.c