On 2020/06/30 3:35, Kanchan Joshi wrote:

On Fri, Jun 26, 2020 at 02:50:20AM +0000, Damien Le Moal wrote:

quoted

On 2020/06/26 2:18, Kanchan Joshi wrote:

quoted

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 <redacted>
Signed-off-by: SelvaKumar S <redacted>
Signed-off-by: Arnav Dawn <redacted>
Signed-off-by: Nitesh Shetty <redacted>
Signed-off-by: Javier Gonzalez <redacted>
---
 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.

-- 
Damien Le Moal
Western Digital Research