On 2020/06/30 16:53, Damien Le Moal wrote: > 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... And yes, REQ_OP_WRITE | REQ_OP_ZONE_APPEND == REQ_OP_ZONE_APPEND... But still not a reason for not setting the op correctly :) -- Damien Le Moal Western Digital Research
