Messages in this thread | | | From | John Garry <> | Subject | Re: [PATCH] block: set rq->cmd_flags with bio->opf instead of data->cmd_flags when bio is not Null | Date | Mon, 28 Jan 2019 15:36:58 +0000 |
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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
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