Pull btrfs updates from David Sterba:
"There are some new user features and the usual load of invisible
enhancements or cleanups.
New features:
- extend mount options to specify zlib compression level, -o
compress=zlib:9
- v2 of ioctl "extent to inode mapping", addressing a usecase where
we want to retrieve more but inaccurate results and do the
postprocessing in userspace, aiding defragmentation or
deduplication tools
- populate compression heuristics logic, do data sampling and try to
guess compressibility by: looking for repeated patterns, counting
unique byte values and distribution, calculating Shannon entropy;
this will need more benchmarking and possibly fine tuning, but the
base should be good enough
- enable indexing for btrfs as lower filesystem in overlayfs
- speedup page cache readahead during send on large files
Internal enhancements:
- more sanity checks of b-tree items when reading them from disk
- more EINVAL/EUCLEAN fixups, missing BLK_STS_* conversion, other
errno or error handling fixes
- remove some homegrown IO-related logic, that's been obsoleted by
core block layer changes (batching, plug/unplug, own counters)
- add ref-verify, optional debugging feature to verify extent
reference accounting
- simplify code handling outstanding extents, make it more clear
where and how the accounting is done
- make delalloc reservations per-inode, simplify the code and make
the logic more straightforward
- extensive cleanup of delayed refs code
Notable fixes:
- fix send ioctl on 32bit with 64bit kernel"
* 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (102 commits)
btrfs: Fix bug for misused dev_t when lookup in dev state hash table.
Btrfs: heuristic: add Shannon entropy calculation
Btrfs: heuristic: add byte core set calculation
Btrfs: heuristic: add byte set calculation
Btrfs: heuristic: add detection of repeated data patterns
Btrfs: heuristic: implement sampling logic
Btrfs: heuristic: add bucket and sample counters and other defines
Btrfs: compression: separate heuristic/compression workspaces
btrfs: move btrfs_truncate_block out of trans handle
btrfs: don't call btrfs_start_delalloc_roots in flushoncommit
btrfs: track refs in a rb_tree instead of a list
btrfs: add a comp_refs() helper
btrfs: switch args for comp_*_refs
btrfs: make the delalloc block rsv per inode
btrfs: add tracepoints for outstanding extents mods
Btrfs: rework outstanding_extents
btrfs: increase output size for LOGICAL_INO_V2 ioctl
btrfs: add a flags argument to LOGICAL_INO and call it LOGICAL_INO_V2
btrfs: add a flag to iterate_inodes_from_logical to find all extent refs for uncompressed extents
btrfs: send: remove unused code
...