| Message ID | 20191028170543.27591-1-anton.ivanov@cambridgegreys.com |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | um: Entrust re-queue to the upper layers | expand |
On 10/28/19 11:05 AM, Anton Ivanov wrote: > Fixes crashes due to ubd requeue logic conflicting with the block-mq > one. First of all, great work getting this far! This is surely a bug. Probably needs a Fixes entry, and a CC stable. There are actually two cases that'll return an error here, and one is global and the other is per-device. If the kmalloc() fails in ubd_queue_one_vec(), we should be returning BLK_STS_RESOURCE. Didn't look at the -EAGAIN part, but maybe that's a global resource as well when it fails? If so, then both should return BLK_STS_RESOURCE. If not, then that should return BLK_STS_DEV_RESOURCE, as your change did. Hence if both are global, just make it: if (ret < 0) res = BLK_STS_DEV_RESOURCE; and if one is a per-device thing, then I'd make ubd_queue_one_vec() return the BLK_STS_* type and propagate that down to the caller.
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 33c1cd6a12ac..3fe2a986f2c4 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1404,7 +1404,7 @@ static blk_status_t ubd_queue_rq(struct blk_mq_hw_ctx *hctx, spin_unlock_irq(&ubd_dev->lock); if (ret < 0) - blk_mq_requeue_request(req, true); + return BLK_STS_DEV_RESOURCE; return res; }
Fixes crashes due to ubd requeue logic conflicting with the block-mq one. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> --- arch/um/drivers/ubd_kern.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)