In function blk_mq_make_request(), though data->cmd_flags will be
initialized with bio->opf, later bio->opf may be set as REQ_INTEGRITY
if enabled DIX. So need to use bio->opf instead of data->cmd_flags in
function blk_mq_rq_ctx_init(), or flags REQ_INTEGRITY will not be set
for rq->cmd_flags. It will cause dix=0 in function
sd_setup_read_write_cmnd() when enabled DIX, which will cause IO
exception when enabled DIX.
For some IOs such as internal IO from SCSI layer, the parameter bio of
function blk_mq_get_request() is Null, so need to check bio to
decise rq->cmd_flags.
Fixes: f9afca4d367b ("blk-mq: pass in request/bio flags to queue mapping")
Signed-off-by: Xiang Chen <[email protected]>
Reviewed-by: John Garry <[email protected]>
---
block/blk-mq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3ba37b9..c4a1c63 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -394,7 +394,7 @@ static struct request *blk_mq_get_request(struct request_queue *q,
return NULL;
}
- rq = blk_mq_rq_ctx_init(data, tag, data->cmd_flags);
+ rq = blk_mq_rq_ctx_init(data, tag, bio ? bio->bi_opf : data->cmd_flags);
if (!op_is_flush(data->cmd_flags)) {
rq->elv.icq = NULL;
if (e && e->type->ops.prepare_request) {
--
2.8.1
+cc Jens + linux-block
?? 2019/1/24 21:43, chenxiang д??:
> In function blk_mq_make_request(), though data->cmd_flags will be
> initialized with bio->opf, later bio->opf may be set as REQ_INTEGRITY
> if enabled DIX. So need to use bio->opf instead of data->cmd_flags in
> function blk_mq_rq_ctx_init(), or flags REQ_INTEGRITY will not be set
> for rq->cmd_flags. It will cause dix=0 in function
> sd_setup_read_write_cmnd() when enabled DIX, which will cause IO
> exception when enabled DIX.
>
> For some IOs such as internal IO from SCSI layer, the parameter bio of
> function blk_mq_get_request() is Null, so need to check bio to
> decise rq->cmd_flags.
>
> Fixes: f9afca4d367b ("blk-mq: pass in request/bio flags to queue mapping")
>
> Signed-off-by: Xiang Chen <[email protected]>
> Reviewed-by: John Garry <[email protected]>
> ---
> block/blk-mq.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 3ba37b9..c4a1c63 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -394,7 +394,7 @@ static struct request *blk_mq_get_request(struct request_queue *q,
> return NULL;
> }
>
> - rq = blk_mq_rq_ctx_init(data, tag, data->cmd_flags);
> + rq = blk_mq_rq_ctx_init(data, tag, bio ? bio->bi_opf : data->cmd_flags);
> if (!op_is_flush(data->cmd_flags)) {
> rq->elv.icq = NULL;
> if (e && e->type->ops.prepare_request) {
> > for rq->cmd_flags. It will cause dix=0 in function
> > sd_setup_read_write_cmnd() when enabled DIX, which will cause IO
> > exception when enabled DIX.
> >
> > For some IOs such as internal IO from SCSI layer, the parameter bio of
> > function blk_mq_get_request() is Null, so need to check bio to
> > decise rq->cmd_flags.
We have data->cmd_flags to deal with the NULL bio case.
blk_mq_make_request initializes data->cmd_flags from bio->bi_opf
just before calling blk_mq_get_request, so I'm really missing what you
are trying to fix here.
On 28/01/2019 14:07, Christoph Hellwig wrote:
>>> for rq->cmd_flags. It will cause dix=0 in function
>>> sd_setup_read_write_cmnd() when enabled DIX, which will cause IO
>>> exception when enabled DIX.
>>>
>>> For some IOs such as internal IO from SCSI layer, the parameter bio of
>>> function blk_mq_get_request() is Null, so need to check bio to
>>> decise rq->cmd_flags.
>
> We have data->cmd_flags to deal with the NULL bio case.
> blk_mq_make_request initializes data->cmd_flags from bio->bi_opf
> just before calling blk_mq_get_request, so I'm really missing what you
> are trying to fix here.
As I understood, the problem is the scenario of calling
blk_mq_make_request()->bio_integrity_prep() where we then allocate a bio
integrity payload in calling bio_integrity_alloc().
In this case, bio_integrity_alloc() sets bio->bi_opf |= REQ_INTEGRITY,
which is no longer consistent with data.cmd_flags.
John
>
> .
>
On Mon, Jan 28, 2019 at 03:36:58PM +0000, John Garry wrote:
> As I understood, the problem is the scenario of calling
> blk_mq_make_request()->bio_integrity_prep() where we then allocate a bio
> integrity payload in calling bio_integrity_alloc().
>
> In this case, bio_integrity_alloc() sets bio->bi_opf |= REQ_INTEGRITY, which
> is no longer consistent with data.cmd_flags.
I don't see how that could happen:
static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
{
...
if (!bio_integrity_prep(bio))
return BLK_QC_T_NONE;
...
data.cmd_flags = bio->bi_opf;
rq = blk_mq_get_request(q, bio, &data);
On 28/01/2019 15:57, Christoph Hellwig wrote:
> On Mon, Jan 28, 2019 at 03:36:58PM +0000, John Garry wrote:
>> As I understood, the problem is the scenario of calling
>> blk_mq_make_request()->bio_integrity_prep() where we then allocate a bio
>> integrity payload in calling bio_integrity_alloc().
>>
>> In this case, bio_integrity_alloc() sets bio->bi_opf |= REQ_INTEGRITY, which
>> is no longer consistent with data.cmd_flags.
>
> I don't see how that could happen:
>
> static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
> {
> ...
>
> if (!bio_integrity_prep(bio))
> return BLK_QC_T_NONE;
>
> ...
>
> data.cmd_flags = bio->bi_opf;
> rq = blk_mq_get_request(q, bio, &data);
>
>
Your code is different to mine, then I see that this has been fixed in
5.0-rc3:
commit 7809167da5c86fd6bf309b33dee7a797e263342f
Author: Ming Lei <[email protected]>
Date: Wed Jan 16 19:08:15 2019 +0800
block: don't lose track of REQ_INTEGRITY flag
We need to pass bio->bi_opf after bio intergrity preparing, otherwise
the flag of REQ_INTEGRITY may not be set on the allocated request, then
breaks block integrity.
Fixes: f9afca4d367b ("blk-mq: pass in request/bio flags to queue
mapping")
Cc: Hannes Reinecke <[email protected]>
Cc: Keith Busch <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Sorry for the noise,
John
> .
>
在 2019/1/28 23:57, Christoph Hellwig 写道:
> On Mon, Jan 28, 2019 at 03:36:58PM +0000, John Garry wrote:
>> As I understood, the problem is the scenario of calling
>> blk_mq_make_request()->bio_integrity_prep() where we then allocate a bio
>> integrity payload in calling bio_integrity_alloc().
>>
>> In this case, bio_integrity_alloc() sets bio->bi_opf |= REQ_INTEGRITY, which
>> is no longer consistent with data.cmd_flags.
> I don't see how that could happen:
>
> static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
> {
> ...
>
> if (!bio_integrity_prep(bio))
> return BLK_QC_T_NONE;
>
> ...
>
> data.cmd_flags = bio->bi_opf;
> rq = blk_mq_get_request(q, bio, &data);
Sorry to disturb, i used kernel 5.0-rc1 which has the issue, and it is
fixed on linux-next branch.
>
>
> .
>