RE: [PATCH] blk-mq: use BLK_MQ_NO_TAG for no tag

Tianxianting
2020-08-24T07:08:01Z

Hi Jens
Sorry to trouble you, I am very sorry for taking it for granted for the patch compile.

I checked, compile for the two changed files are OK:
block/blk-core.c
block/blk-mq-sched.c

Compile failed for the function in below header file:
include/linux/blk-mq.h: request_to_qc_t()
- if (rq->tag != -1)
+ if (rq->tag != BLK_MQ_NO_TAG)

BLK_MQ_NO_TAG is defined in 'block/blk-mq-tag.h', if I include this header file in 'include/linux/blk-mq.h' via '#include "../../block/blk-mq-tag.h"',
Many other similar compile failed happen, for example:
In file included from ./include/linux/../../block/blk-mq-tag.h:5:0,
from ./include/linux/blk-mq.h:8,
from block/blk.h:6,
from block/bio.c:24:
./include/linux/../../block/blk-mq.h:21:29: error: ‘HCTX_MAX_TYPES’ undeclared here (not in a function); did you mean ‘KOBJ_NS_TYPES’?
struct list_head rq_lists[HCTX_MAX_TYPES];
^~~~~~~~~~~~~~
If I moved below BLK_MQ_NO_TAG definition to 'include/linux/blk-mq.h', all kernel compiles are ok with the patch.
enum {
BLK_MQ_NO_TAG = -1U,
BLK_MQ_TAG_MIN = 1,
BLK_MQ_TAG_MAX = BLK_MQ_NO_TAG - 1,
};
Will you accept above moving of BLK_MQ_NO_TAG to 'include/linux/blk-mq.h'?
Thanks

-----Original Message-----
From: Jens Axboe [mailto:axboe@kernel.dk]
Sent: Monday, August 24, 2020 4:58 AM
To: tianxianting (RD) <tian.xianting@h3c.com>; ast@kernel.org; daniel@iogearbox.net; kafai@fb.com; songliubraving@fb.com; yhs@fb.com; andriin@fb.com; john.fastabend@gmail.com; kpsingh@chromium.org
Cc: linux-block@vger.kernel.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH] blk-mq: use BLK_MQ_NO_TAG for no tag

On 8/23/20 9:44 AM, Xianting Tian wrote:
> Replace various magic -1 constants for tags with BLK_MQ_NO_TAG.

Doesn't look like this patch was even compiled...

--
Jens Axboe