[5.20,v3,0/2] dm: improve bio splitting at expense of requeue complexity

Message

Mike Snitzer July 6, 2022, 5:44 p.m. UTC

This v3 moves all bio_rewind() code to drivers/md/dm-io-rewind.c for
exclussive use by DM core's dm_io requeue support via dm_io_rewind().

It was determined that block core doesn't need to expose bio_rewind()
for more general use. If/when that changes we can revisit, armed with
the understanding of how DM's use of bio_rewind() has faired.

These changes are now staged for 5.20 inclussion via linux-dm.git

Ming Lei (2):
  dm: add bio_rewind() API to DM core
  dm: add two stage requeue mechanism

 drivers/md/Makefile       |   2 +-
 drivers/md/dm-core.h      |  13 +++-
 drivers/md/dm-io-rewind.c | 166 ++++++++++++++++++++++++++++++++++++++++++++++
 drivers/md/dm.c           | 121 +++++++++++++++++++++++++--------
 4 files changed, 273 insertions(+), 29 deletions(-)
 create mode 100644 drivers/md/dm-io-rewind.c