[md PATCH 00/10] Simplify bio splitting and related code.

[NeilBrown <neilb@suse.com>]

This is part of my little project to make bio splitting
in Linux uniform and dead-lock free, in a way that will mean
that we can get rid of all the bioset threads.

The basic approach is that when a bio needs to be split, we call
bio_split(), bio_chain() and then generic_make_request().
We then proceed to handle the remainder without further splitting.
Recent changes to generic_make_request() ensure that this will
be safe from deadlocks, providing each bioset is used only once
in the stack.

This leads to simpler code in various places.  In particular, the
splitting of bios that is needed to work around known bad blocks
is now much less complex.  There is only ever one r1bio per bio.

As you can see from
 10 files changed, 335 insertions(+), 540 deletions(-)
there is a net reduction in code.

Thanks,
NeilBrown

---

NeilBrown (10):
      md/raid1: simplify the splitting of requests.
      md/raid1: simplify alloc_behind_master_bio()
      Revert "block: introduce bio_copy_data_partial"
      md/raid1: simplify handle_read_error().
      md/raid1: factor out flush_bio_list()
      md/raid10: simplify the splitting of requests.
      md/raid10: simplify handle_read_error()
      md/raid5: make chunk_aligned_read() split bios more cleanly.
      md/linear: improve bio splitting.
      md/raid0: fix up bio splitting.


 block/bio.c         |   60 ++-------
 drivers/md/linear.c |   75 +++++------
 drivers/md/raid0.c  |   73 +++++------
 drivers/md/raid1.c  |  346 ++++++++++++++++++++-------------------------------
 drivers/md/raid1.h  |    2 
 drivers/md/raid10.c |  282 ++++++++++++++----------------------------
 drivers/md/raid10.h |    1 
 drivers/md/raid5.c  |   33 +++--
 drivers/md/raid5.h  |    1 
 include/linux/bio.h |    2 
 10 files changed, 335 insertions(+), 540 deletions(-)

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