On 2020/06/30 16:43, Kanchan Joshi wrote: > On Tue, Jun 30, 2020 at 12:37:07AM +0000, Damien Le Moal wrote: >> On 2020/06/30 3:35, Kanchan Joshi wrote: >>> On Fri, Jun 26, 2020 at 02:50:20AM +0000, Damien Le Moal wrote: >>>> On 2020/06/26 2:18, Kanchan Joshi wrote: >>>>> Introduce RWF_ZONE_APPEND flag to represent zone-append. User-space >>>>> sends this with write. Add IOCB_ZONE_APPEND which is set in >>>>> kiocb->ki_flags on receiving RWF_ZONE_APPEND. >>>>> Make direct IO submission path use IOCB_ZONE_APPEND to send bio with >>>>> append op. Direct IO completion returns zone-relative offset, in sector >>>>> unit, to upper layer using kiocb->ki_complete interface. >>>>> Report error if zone-append is requested on regular file or on sync >>>>> kiocb (i.e. one without ki_complete). >>>>> >>>>> Signed-off-by: Kanchan Joshi <joshi.k@xxxxxxxxxxx> >>>>> Signed-off-by: SelvaKumar S <selvakuma.s1@xxxxxxxxxxx> >>>>> Signed-off-by: Arnav Dawn <a.dawn@xxxxxxxxxxx> >>>>> Signed-off-by: Nitesh Shetty <nj.shetty@xxxxxxxxxxx> >>>>> Signed-off-by: Javier Gonzalez <javier.gonz@xxxxxxxxxxx> >>>>> --- >>>>> fs/block_dev.c | 28 ++++++++++++++++++++++++---- >>>>> include/linux/fs.h | 9 +++++++++ >>>>> include/uapi/linux/fs.h | 5 ++++- >>>>> 3 files changed, 37 insertions(+), 5 deletions(-) >>>>> >>>>> diff --git a/fs/block_dev.c b/fs/block_dev.c >>>>> index 47860e5..5180268 100644 >>>>> --- a/fs/block_dev.c >>>>> +++ b/fs/block_dev.c >>>>> @@ -185,6 +185,10 @@ static unsigned int dio_bio_write_op(struct kiocb *iocb) >>>>> /* avoid the need for a I/O completion work item */ >>>>> if (iocb->ki_flags & IOCB_DSYNC) >>>>> op |= REQ_FUA; >>>>> + >>>>> + if (iocb->ki_flags & IOCB_ZONE_APPEND) >>>>> + op |= REQ_OP_ZONE_APPEND; >>>> >>>> This is wrong. REQ_OP_WRITE is already set in the declaration of "op". How can >>>> this work ? >>> REQ_OP_ZONE_APPEND will override the REQ_WRITE op, while previously set op >>> flags (REQ_FUA etc.) will be retained. But yes, this can be made to look >>> cleaner. >>> V3 will include the other changes you pointed out. Thanks for the review. >>> >> >> REQ_OP_WRITE and REQ_OP_ZONE_APPEND are different bits, so there is no >> "override". A well formed BIO bi_opf is one op+flags. Specifying multiple OP >> codes does not make sense. > > one op+flags behavior is retained here. OP is not about bits (op flags are). > Had it been, REQ_OP_WRITE (value 1) can not be differentiated from > REQ_OP_ZONE_APPEND (value 13). > We do not do "bio_op(bio) & REQ_OP_WRITE", rather we look at the > absolute value "bio_op(bio) == REQ_OP_WRITE". Sure, the ops are not bits like the flags, but (excluding the flags) doing: op |= REQ_OP_ZONE_APPEND; will give you op == (REQ_OP_WRITE | REQ_OP_ZONE_APPEND). That's not what you want... -- Damien Le Moal Western Digital Research
