This patchset can be fetched from github: https://github.com/adam900710/linux.git wang_dedupe_20160524
In this update, the patchset goes through another re-organization along with other fixes to address comments from community. 1) Move on-disk backend and dedupe props out of the patchset Suggested by David. There is still some discussion on the on-disk format. And dedupe prop is still not 100% determined. So it's better to focus on the current in-memory backend only, which doesn't bring any on-disk format change. Once the framework is done, new backends and props can be added more easily. 2) Better enable/disable and buffered write race avoidance Inspired by Mark. Although in previous version, we didn't trigger it with our test case, but if we manually add delay(5s) to __btrfs_buffered_write(), it's possible to trigger disable and buffered write race. The cause is, there is a windows between __btrfs_buffered_write() and btrfs_dirty_pages(). In that window, sync_filesystem() can return very quickly since there is no dirty page. During that window, dedupe disable can happen and finish, and buffered writer may access to the NULL pointer of dedupe info. Now we use sb->s_writers.rw_sem to wait all current writers and block further writers, then sync the fs, change dedupe status and finally unblock writers. (Like freeze) This provides clearer logical and code, and safer than previous method, because there is no windows before we dirty pages. 3) Fix ENOSPC problem with better solution. Pointed out by Josef. The last 2 patches from Wang fixes ENOSPC problem, in a more comprehensive method for delalloc metadata reservation. Alone with small outstanding extents improvement, to co-operate with tunable max extent size. Now the whole patchset will only add in-memory backend as a whole. No other backend nor prop. So we can focus on the framework itself. Next version will focus on ioctl interface modification suggested by David. Thanks, Qu Changelog: v2: Totally reworked to handle multiple backends v3: Fix a stupid but deadly on-disk backend bug Add handle for multiple hash on same bytenr corner case to fix abort trans error Increase dedup rate by enhancing delayed ref handler for both backend. Move dedup_add() to run_delayed_ref() time, to fix abort trans error. Increase dedup block size up limit to 8M. v4: Add dedup prop for disabling dedup for given files/dirs. Merge inmem_search() and ondisk_search() into generic_search() to save some code Fix another delayed_ref related bug. Use the same mutex for both inmem and ondisk backend. Move dedup_add() back to btrfs_finish_ordered_io() to increase dedup rate. v5: Reuse compress routine for much simpler dedup function. Slightly improved performance due to above modification. Fix race between dedup enable/disable Fix for false ENOSPC report v6: Further enable/disable race window fix. Minor format change according to checkpatch. v7: Fix one concurrency bug with balance. Slightly modify return value from -EINVAL to -EOPNOTSUPP for btrfs_dedup_ioctl() to allow progs to distinguish unsupported commands and wrong parameter. Rebased to integration-4.6. v8: Rename 'dedup' to 'dedupe'. Add support to allow dedupe and compression work at the same time. Fix several balance related bugs. Special thanks to Satoru Takeuchi, who exposed most of them. Small dedupe hit case performance improvement. v9: Re-order the patchset to completely separate pure in-memory and any on-disk format change. Fold bug fixes into its original patch. v10: Adding back missing bug fix patch. Reduce on-disk item size. Hide dedupe ioctl under CONFIG_BTRFS_DEBUG. v11: Remove other backend and props support to focus on the framework and in-memory backend. Suggested by David. Better disable and buffered write race protection. Comprehensive fix to dedupe metadata ENOSPC problem. Qu Wenruo (3): btrfs: delayed-ref: Add support for increasing data ref under spinlock btrfs: dedupe: Inband in-memory only de-duplication implement btrfs: relocation: Enhance error handling to avoid BUG_ON Wang Xiaoguang (10): btrfs: dedupe: Introduce dedupe framework and its header btrfs: dedupe: Introduce function to initialize dedupe info btrfs: dedupe: Introduce function to add hash into in-memory tree btrfs: dedupe: Introduce function to remove hash from in-memory tree btrfs: dedupe: Introduce function to search for an existing hash btrfs: dedupe: Implement btrfs_dedupe_calc_hash interface btrfs: ordered-extent: Add support for dedupe btrfs: dedupe: Add ioctl for inband dedupelication btrfs: improve inode's outstanding_extents computation btrfs: dedupe: fix false ENOSPC fs/btrfs/Makefile | 2 +- fs/btrfs/ctree.h | 25 +- fs/btrfs/dedupe.c | 710 ++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/dedupe.h | 210 +++++++++++++ fs/btrfs/delayed-ref.c | 30 +- fs/btrfs/delayed-ref.h | 8 + fs/btrfs/disk-io.c | 4 + fs/btrfs/extent-tree.c | 83 +++++- fs/btrfs/extent_io.c | 63 +++- fs/btrfs/extent_io.h | 15 +- fs/btrfs/file.c | 26 +- fs/btrfs/free-space-cache.c | 5 +- fs/btrfs/inode-map.c | 4 +- fs/btrfs/inode.c | 434 ++++++++++++++++++++++----- fs/btrfs/ioctl.c | 80 ++++- fs/btrfs/ordered-data.c | 46 ++- fs/btrfs/ordered-data.h | 14 + fs/btrfs/relocation.c | 46 ++- fs/btrfs/sysfs.c | 2 + include/uapi/linux/btrfs.h | 41 +++ 20 files changed, 1701 insertions(+), 147 deletions(-) create mode 100644 fs/btrfs/dedupe.c create mode 100644 fs/btrfs/dedupe.h -- 2.8.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
