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 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
