Re: [PATCH] Add cmd_flags to print_req_error

From: Jens Axboe
Date: Mon Oct 29 2018 - 18:39:12 EST

On 10/28/18 6:57 PM, Balbir Singh wrote:
> I ran into a bug where after hibernation due to incompatible
> backends, the block driver returned BLK_STS_NOTSUPP, with the
> current message it's hard to find out what the command flags
> were. Adding req->cmd_flags help make the problem easier to
> diagnose.

I recently did the same thing to debug something, so I like
this change. One comment:

> + printk_ratelimited(KERN_ERR "%s: %s error, dev %s, sector %llu flags %llx\n",
> + __func__, blk_errors[idx].name,
> + req->rq_disk ? req->rq_disk->disk_name : "?",
> + (unsigned long long)blk_rq_pos(req),
> + (unsigned long long)req->cmd_flags);

Why are you casting it to unsigned long long for printing? A simple
%x should suffice, no cast necessary.

Jens Axboe