[Bcache v13 00/16]

[Kent Overstreet <koverstreet@google.com>]

bcache: a cache for arbitrary block devices using an SSD.

Short overview:
Bcache does both writethrough and writeback caching. It presents itself as a
new block device, a bit like say md. You can cache an arbitrary number of
block devices with a single cache device, and attach and detach things at
runtime - it's quite flexible.

It's very fast. It uses a b+ tree for the index, along with a journal to
coalesce index updates, and a bunch of other cool tricks like auxiliary binary
search trees with software floating point keys for searching within btree
nodes.

Bcache is solid, production ready code. There are still bugs being found that
affect specific configurations, but there haven't been any major issues found
in awhile - it's well past time I started working on getting it into mainline.

It's a lot of code - I tried to split it out so that it'd make some sort of
sense for reviewing. Let me know if there's anything else I can do to make
review easier.

TODO/known issues:

__up_write() needs to be exported for bcache to compile as a module - it's
used for bypassing lockdep when traversing the btree during garbage
collection. If someone else knows a better solution, please let me know.

The userspace interface is going to change before it goes in. The general
consensus at LSF was that we don't want yet another interface for
probing/managing block devices, and dm exists so we may as well use that. I
don't think anyone's started on that yet, though.

Documentation needs to be updated. That's being actively worked on, though.

Kent Overstreet (16):
  Only clone bio vecs that are in use
  Bio pool freeing
  Revert "rw_semaphore: remove up/down_read_non_owner"
  Fix ratelimit macro to compile in c99 mode
  Export get_random_int()
  Export blk_fill_rwbs()
  Closures
  bcache: Documentation, and changes to generic code
  Bcache: generic utility code
  bcache: Superblock/initialization/sysfs code
  bcache: Core btree code
  bcache: Bset code (lookups within a btree node)
  bcache: Journalling
  bcache: Request, io and allocation code
  bcache: Writeback
  bcache: Debug and tracing code

 Documentation/ABI/testing/sysfs-block-bcache |  156 ++
 Documentation/bcache.txt                     |  255 +++
 block/blk-core.c                             |    2 +-
 drivers/block/Kconfig                        |    2 +
 drivers/block/Makefile                       |    1 +
 drivers/block/bcache/Kconfig                 |   42 +
 drivers/block/bcache/Makefile                |    8 +
 drivers/block/bcache/alloc.c                 |  591 +++++++
 drivers/block/bcache/bcache.h                |  839 ++++++++++
 drivers/block/bcache/bset.c                  | 1149 +++++++++++++
 drivers/block/bcache/bset.h                  |  218 +++
 drivers/block/bcache/btree.c                 | 2249 ++++++++++++++++++++++++++
 drivers/block/bcache/btree.h                 |  272 ++++
 drivers/block/bcache/debug.c                 |  574 +++++++
 drivers/block/bcache/debug.h                 |   53 +
 drivers/block/bcache/io.c                    |  198 +++
 drivers/block/bcache/journal.c               |  722 +++++++++
 drivers/block/bcache/journal.h               |  113 ++
 drivers/block/bcache/request.c               | 1470 +++++++++++++++++
 drivers/block/bcache/request.h               |   58 +
 drivers/block/bcache/stats.c                 |  243 +++
 drivers/block/bcache/stats.h                 |   58 +
 drivers/block/bcache/super.c                 | 2000 +++++++++++++++++++++++
 drivers/block/bcache/sysfs.c                 |  802 +++++++++
 drivers/block/bcache/sysfs.h                 |   99 ++
 drivers/block/bcache/trace.c                 |   26 +
 drivers/block/bcache/util.c                  |  572 +++++++
 drivers/block/bcache/util.h                  |  657 ++++++++
 drivers/block/bcache/writeback.c             |  518 ++++++
 drivers/block/rbd.c                          |    2 +-
 drivers/char/random.c                        |    1 +
 drivers/md/dm.c                              |   27 +-
 drivers/md/md.c                              |    3 +-
 fs/bio.c                                     |   55 +-
 include/linux/bio.h                          |    7 +-
 include/linux/blk_types.h                    |    2 +
 include/linux/cgroup_subsys.h                |    6 +
 include/linux/closure.h                      |  614 +++++++
 include/linux/ratelimit.h                    |    2 +-
 include/linux/rwsem.h                        |   10 +
 include/linux/sched.h                        |    4 +
 include/trace/events/bcache.h                |  257 +++
 kernel/fork.c                                |    4 +
 kernel/rwsem.c                               |   16 +
 kernel/trace/blktrace.c                      |    1 +
 lib/Kconfig                                  |    3 +
 lib/Kconfig.debug                            |    9 +
 lib/Makefile                                 |    2 +
 lib/closure.c                                |  363 +++++
 49 files changed, 15288 insertions(+), 47 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-block-bcache
 create mode 100644 Documentation/bcache.txt
 create mode 100644 drivers/block/bcache/Kconfig
 create mode 100644 drivers/block/bcache/Makefile
 create mode 100644 drivers/block/bcache/alloc.c
 create mode 100644 drivers/block/bcache/bcache.h
 create mode 100644 drivers/block/bcache/bset.c
 create mode 100644 drivers/block/bcache/bset.h
 create mode 100644 drivers/block/bcache/btree.c
 create mode 100644 drivers/block/bcache/btree.h
 create mode 100644 drivers/block/bcache/debug.c
 create mode 100644 drivers/block/bcache/debug.h
 create mode 100644 drivers/block/bcache/io.c
 create mode 100644 drivers/block/bcache/journal.c
 create mode 100644 drivers/block/bcache/journal.h
 create mode 100644 drivers/block/bcache/request.c
 create mode 100644 drivers/block/bcache/request.h
 create mode 100644 drivers/block/bcache/stats.c
 create mode 100644 drivers/block/bcache/stats.h
 create mode 100644 drivers/block/bcache/super.c
 create mode 100644 drivers/block/bcache/sysfs.c
 create mode 100644 drivers/block/bcache/sysfs.h
 create mode 100644 drivers/block/bcache/trace.c
 create mode 100644 drivers/block/bcache/util.c
 create mode 100644 drivers/block/bcache/util.h
 create mode 100644 drivers/block/bcache/writeback.c
 create mode 100644 include/linux/closure.h
 create mode 100644 include/trace/events/bcache.h
 create mode 100644 lib/closure.c

-- 
1.7.9.rc2