On 10/9/21 06:32, Yanling Song wrote:
op_is_write() does not meet our requirement: Both read and write
commands have to be checked, not just write command.
Right, I should have proposed to compare the operation type with
REQ_OP_READ / REQ_OP_WRITE. However, that approach only works for SCSI
commands that come from the block layer and not for SG_IO
(REQ_OP_DRV_IN/OUT).
Please remove all of the above code and use blk_rq_pos(),
blk_rq_sectors() and rq->cmd_flags & REQ_FUA instead.
I did not quite get your point. The above is commonly used in many
similar use cases. For example: megasas_build_ldio() in
megaraid_sas_base.c.
What's the benefit to switch to another way: use
blk_rq_pos(),blk_rq_sectors()?
I expect that using blk_rq_pos() and blk_rq_sectors() will result in
faster code. However, these functions only work for SCSI commands that
come from the block layer and not for SG_IO. If you want a common code
path for SG_IO and block layer requests, please take a look at how
get_unaligned_be*() is used in drivers/scsi/scsi_trace.c.
Thanks,
Bart.
