[5.20,0/4] block/dm: add bio_rewind for improving dm requeue

Message

Ming Lei June 24, 2022, 2:12 p.m. UTC

Hello Guys,

The 1st patch adds bio_rewind which can restore bio to original position
by recording sectors between the original position to bio's end sector
if the bio's end sector won't change, which should be very common to
see.

The 2nd and 3rd patch cleans up dm code for handling requeue &
completion.

The last patch implements 2 stage dm io requeue for avoiding to allocate
one bio beforehand for just handling requeue which is one unusual event.
The 1st stage requeue is added for cloning & restoring original bio in wq
context, then 2nd stage requeue will use that as original bio for
handling requeue.


Ming Lei (4):
  block: add bio_rewind() API
  dm: add new helper for handling dm_io requeue
  dm: improve handling for DM_REQUEUE and AGAIN
  dm: add two stage requeue

 block/bio-integrity.c       |  19 ++++
 block/bio.c                 |  19 ++++
 block/blk-crypto-internal.h |   7 ++
 block/blk-crypto.c          |  23 +++++
 drivers/md/dm-core.h        |  11 ++-
 drivers/md/dm.c             | 180 ++++++++++++++++++++++++++++--------
 include/linux/bio.h         |  21 +++++
 include/linux/bvec.h        |  33 +++++++
 8 files changed, 271 insertions(+), 42 deletions(-)