Hi all, This series improves the performance (and correctness for some filesystems) by adding the ability to cache iomap mappings in the kernel. For filesystems that can change mapping states during pagecache writeback (e.g. unwritten extent conversion) this is absolutely necessary to deal with races with writes to the pagecache because writeback does not take i_rwsem. For everyone else, it simply eliminates roundtrips to userspace. If you're going to start using this code, I strongly recommend pulling from my git trees, which are linked below. This has been running on the djcloud for months with no problems. Enjoy! Comments and questions are, as always, welcome. --D kernel git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=fuse-iomap-cache --- Commits in this patchset: * fuse: cache iomaps * fuse: use the iomap cache for iomap_begin * fuse: invalidate iomap cache after file updates * fuse: enable iomap cache management --- fs/fuse/fuse_i.h | 110 +++ fs/fuse/fuse_trace.h | 646 +++++++++++++++++ fs/fuse/iomap_cache.h | 122 +++ include/uapi/linux/fuse.h | 38 + fs/fuse/Makefile | 2 fs/fuse/dev.c | 46 + fs/fuse/file.c | 10 fs/fuse/file_iomap.c | 679 +++++++++++++++++- fs/fuse/iomap_cache.c | 1743 +++++++++++++++++++++++++++++++++++++++++++++ 9 files changed, 3377 insertions(+), 19 deletions(-) create mode 100644 fs/fuse/iomap_cache.h create mode 100644 fs/fuse/iomap_cache.c
