[PATCH v3 0/4] multi-page bvec configuration for integrity payload

[Jinyoung Choi]

In the case of NVMe, it has an integrity payload consisting of one segment.
So, rather than configuring SG_LIST, it was changed by direct DMA mapping.

The page-merge is not performed for the struct bio_vec when creating 
a integrity payload in block.
As a result, when creating an integrity paylaod beyond one page, each 
struct bio_vec is generated, and its bv_len does not exceed the PAGESIZE.

To solve it, bio_integrity_add_page() should just add to the existing 
bvec, similar to bio_add_page() and friends. 

(ref: https://lore.kernel.org/linux-nvme/yq18rewbmay.fsf@xxxxxxxxxxxxxxxxxxxx/T/#t)


Tested like this:

- Format (support pi)
$ sudo nvme format /dev/nvme2n1 --force -n 1 -i 1 -p 0 -m 0 -l 1 -r

- Run FIO
[global]
ioengine=libaio
group_reporting

[job]
bs=512k
iodepth=256
rw=write
numjobs=8
direct=1
runtime=10s
filename=/dev/nvme2n1

- Result
...
[   93.496218] nvme2n1: I/O Cmd(0x1) @ LBA 62464, 1024 blocks, I/O Error (sct 0x2 / sc 0x82) MORE
[   93.496227] protection error, dev nvme2n1, sector 62464 op 0x1:(WRITE) flags 0x18800 phys_seg 3 prio class 2
[   93.538788] nvme2n1: I/O Cmd(0x1) @ LBA 6144, 1024 blocks, I/O Error (sct 0x2 / sc 0x82) MORE
[   93.538798] protection error, dev nvme2n1, sector 6144 op 0x1:(WRITE) flags 0x18800 phys_seg 3 prio class 2
[   93.566231] nvme2n1: I/O Cmd(0x1) @ LBA 124928, 1024 blocks, I/O Error (sct 0x0 / sc 0x4)
[   93.566241] I/O error, dev nvme2n1, sector 124928 op 0x1:(WRITE) flags 0x18800 phys_seg 3 prio class 2
[   93.694147] nvme2n1: I/O Cmd(0x1) @ LBA 64512, 1024 blocks, I/O Error (sct 0x2 / sc 0x82) MORE
[   93.694155] protection error, dev nvme2n1, sector 64512 op 0x1:(WRITE) flags 0x18800 phys_seg 3 prio class 2
[   93.694299] nvme2n1: I/O Cmd(0x1) @ LBA 5120, 1024 blocks, I/O Error (sct 0x2 / sc 0x82) MORE
[   93.694305] protection error, dev nvme2n1, sector 5120 op 0x1:(WRITE) flags 0x18800 phys_seg 3 prio class 2
...

Changes to v2:
- apply review related to comment (by Christoph)

Changes to v1:
- add a patch to modify the location of the bi_size update code.
- split a patch (create multi-page bvecs in bio_integirty_add_page()).

Jinyoung Choi (4):
  block: make bvec_try_merge_hw_page() non-static
  bio-integrity: update the payload size in bio_integrity_add_page()
  bio-integrity: cleanup adding integrity pages to bip's bvec.
  bio-integrity: create multi-page bvecs in bio_integrity_add_page()

 block/bio-integrity.c               | 49 ++++++++++++++++-------------
 block/bio.c                         |  2 +-
 block/blk.h                         |  4 +++
 drivers/md/dm-crypt.c               |  1 -
 drivers/nvme/host/ioctl.c           |  1 -
 drivers/nvme/target/io-cmd-bdev.c   |  3 +-
 drivers/target/target_core_iblock.c |  3 +-
 7 files changed, 35 insertions(+), 28 deletions(-)

-- 
2.34.1