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authorXiubo Li <xiubli@redhat.com>2020-10-13 22:45:14 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-11-05 11:43:22 +0100
commit742fd49cf811ca164489e339b862e3fb8e240a73 (patch)
tree7444e36cfdd1a5e49f03096227e54a08fe36b96d /drivers/block
parentb71dbaf08f9f5b8fafdeca143c7ed89ed62c1030 (diff)
nbd: make the config put is called before the notifying the waiter
[ Upstream commit 87aac3a80af5cbad93e63250e8a1e19095ba0d30 ] There has one race case for ceph's rbd-nbd tool. When do mapping it may fail with EBUSY from ioctl(nbd, NBD_DO_IT), but actually the nbd device has already unmaped. It dues to if just after the wake_up(), the recv_work() is scheduled out and defers calling the nbd_config_put(), though the map process has exited the "nbd->recv_task" is not cleared. Signed-off-by: Xiubo Li <xiubli@redhat.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/nbd.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 7c577cabb9c3..742f8160b6e2 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -787,9 +787,9 @@ static void recv_work(struct work_struct *work)
blk_mq_complete_request(blk_mq_rq_from_pdu(cmd));
}
+ nbd_config_put(nbd);
atomic_dec(&config->recv_threads);
wake_up(&config->recv_wq);
- nbd_config_put(nbd);
kfree(args);
}