Since we are in the memory reclaim path we need our recv work to be on a
workqueue that has WQ_MEM_RECLAIM set so we can avoid deadlocks. Also
set WQ_HIGHPRI since we are in the completion path for IO.
Signed-off-by: Josef Bacik <jbacik@xxxxxx>
---
drivers/block/nbd.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 99c8446..e0a8d51 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -70,6 +70,7 @@ struct nbd_device {
struct task_struct *task_recv;
struct task_struct *task_setup;
+ struct workqueue_struct *recv_workqueue;
#if IS_ENABLED(CONFIG_DEBUG_FS)
struct dentry *dbg_dir;
#endif
@@ -787,7 +788,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
INIT_WORK(&args[i].work, recv_work);
args[i].nbd = nbd;
args[i].index = i;
- queue_work(system_long_wq, &args[i].work);
+ queue_work(nbd->recv_workqueue, &args[i].work);
}
wait_event_interruptible(nbd->recv_wq,
atomic_read(&nbd->recv_threads) == 0);
@@ -1074,6 +1075,16 @@ static int __init nbd_init(void)
goto out;
}
+ nbd_dev[i].recv_workqueue =
+ alloc_workqueue("knbd-recv",
+ WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
+ if (!nbd_dev[i].recv_workqueue) {
+ blk_mq_free_tag_set(&nbd_dev[i].tag_set);
+ blk_cleanup_queue(disk->queue);
+ put_disk(disk);
+ goto out;
+ }
+
/*
* Tell the block layer that we are not a rotational device
*/
@@ -1115,6 +1126,7 @@ static int __init nbd_init(void)
blk_mq_free_tag_set(&nbd_dev[i].tag_set);
blk_cleanup_queue(nbd_dev[i].disk->queue);
put_disk(nbd_dev[i].disk);
+ destroy_workqueue(nbd_dev[i].recv_workqueue);
}
kfree(nbd_dev);
return err;
@@ -1134,6 +1146,7 @@ static void __exit nbd_cleanup(void)
blk_cleanup_queue(disk->queue);
blk_mq_free_tag_set(&nbd_dev[i].tag_set);
put_disk(disk);
+ destroy_workqueue(nbd_dev[i].recv_workqueue);
}
}
unregister_blkdev(NBD_MAJOR, "nbd");
--
2.5.5
--
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