On 9/6/23 18:38, Nitesh Shetty wrote:
We add two new opcode REQ_OP_COPY_SRC, REQ_OP_COPY_DST.
Since copy is a composite operation involving src and dst sectors/lba,
each needs to be represented by a separate bio to make it compatible
with device mapper.
We expect caller to take a plug and send bio with source information,
followed by bio with destination information.
Once the src bio arrives we form a request and wait for destination
bio. Upon arrival of destination we merge these two bio's and send
corresponding request down to device driver.
Signed-off-by: Nitesh Shetty <nj.shetty@xxxxxxxxxxx>
Signed-off-by: Anuj Gupta <anuj20.g@xxxxxxxxxxx>
---
block/blk-core.c | 7 +++++++
block/blk-merge.c | 41 +++++++++++++++++++++++++++++++++++++++
block/blk.h | 16 +++++++++++++++
block/elevator.h | 1 +
include/linux/bio.h | 6 +-----
include/linux/blk_types.h | 10 ++++++++++
6 files changed, 76 insertions(+), 5 deletions(-)
Having two separate bios is okay, and what one would expect.
What is slightly strange is the merging functionality;
That could do with some more explanation why this approach was taken.
And also some checks in the merging code to avoid merging non-copy
offload bios.
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://listman.redhat.com/mailman/listinfo/dm-devel
