kernel.git/fs/btrfs/compression.h, branch linux-4.16.y

btrfs: compression: add helper for type to string conversion

2018-01-22T15:08:16Z

There are several places opencoding this conversion, add a helper now that we have 3 compression algorithms. Signed-off-by: David Sterba

Btrfs: add __init macro to btrfs init functions

2018-01-22T15:08:11Z

Adding __init macro gives kernel a hint that this function is only used during the initialization phase and its memory resources can be freed up after. Signed-off-by: Liu Bo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: Fix wild memory access in compression level parser

2017-11-27T16:01:11Z

[BUG] Kernel panic when mounting with "-o compress" mount option. KASAN will report like: ------ ================================================================== BUG: KASAN: wild-memory-access in strncmp+0x31/0xc0 Read of size 1 at addr d86735fce994f800 by task mount/662 ... Call Trace: dump_stack+0xe3/0x175 kasan_report+0x163/0x370 __asan_load1+0x47/0x50 strncmp+0x31/0xc0 btrfs_compress_str2level+0x20/0x70 [btrfs] btrfs_parse_options+0xff4/0x1870 [btrfs] open_ctree+0x2679/0x49f0 [btrfs] btrfs_mount+0x1b7f/0x1d30 [btrfs] mount_fs+0x49/0x190 vfs_kern_mount.part.29+0xba/0x280 vfs_kern_mount+0x13/0x20 btrfs_mount+0x31e/0x1d30 [btrfs] mount_fs+0x49/0x190 vfs_kern_mount.part.29+0xba/0x280 do_mount+0xaad/0x1a00 SyS_mount+0x98/0xe0 entry_SYSCALL_64_fastpath+0x1f/0xbe ------ [Cause] For 'compress' and 'compress_force' options, its token doesn't expect any parameter so its args[0] contains uninitialized data. Accessing args[0] will cause above wild memory access. [Fix] For Opt_compress and Opt_compress_force, set compression level to the default. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba [ set the default in advance ] Signed-off-by: David Sterba

Btrfs: add write_flags for compression bio

2017-11-15T13:44:31Z

Compression code path has only flaged bios with REQ_OP_WRITE no matter where the bios come from, but it could be a sync write if fsync starts this writeback or a normal writeback write if wb kthread starts a periodic writeback. It breaks the rule that sync writes and writeback writes need to be differentiated from each other, because from the POV of block layer, all bios need to be recognized by these flags in order to do some management, e.g. throttlling. This passes writeback_control to compression write path so that it can send bios with proper flags to block layer. Signed-off-by: Liu Bo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: allow to set compression level for zlib

2017-11-01T19:45:29Z

Preliminary support for setting compression level for zlib, the following works: $ mount -o compess=zlib # default $ mount -o compess=zlib0 # same $ mount -o compess=zlib9 # level 9, slower sync, less data $ mount -o compess=zlib1 # level 1, faster sync, more data $ mount -o remount,compress=zlib3 # level set by remount The compress-force works the same as compress'. The level is visible in the same format in /proc/mounts. Level set via file property does not work yet. Required patch: "btrfs: prepare for extensions in compression options" Signed-off-by: David Sterba

Merge branch 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

2017-09-15T00:30:49Z

Pull zstd support from Chris Mason: "Nick Terrell's patch series to add zstd support to the kernel has been floating around for a while. After talking with Dave Sterba, Herbert and Phillip, we decided to send the whole thing in as one pull request. zstd is a big win in speed over zlib and in compression ratio over lzo, and the compression team here at FB has gotten great results using it in production. Nick will continue to update the kernel side with new improvements from the open source zstd userland code. Nick has a number of benchmarks for the main zstd code in his lib/zstd commit: I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM. The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor, 16 GB of RAM, and a SSD. I benchmarked using `silesia.tar` [3], which is 211,988,480 B large. Run the following commands for the benchmark: sudo modprobe zstd_compress_test sudo mknod zstd_compress_test c 245 0 sudo cp silesia.tar zstd_compress_test The time is reported by the time of the userland `cp`. The MB/s is computed with 1,536,217,008 B / time(buffer size, hash) which includes the time to copy from userland. The Adjusted MB/s is computed with 1,536,217,088 B / (time(buffer size, hash) - time(buffer size, none)). The memory reported is the amount of memory the compressor requests. | Method | Size (B) | Time (s) | Ratio | MB/s | Adj MB/s | Mem (MB) | |----------|----------|----------|-------|---------|----------|----------| | none | 11988480 | 0.100 | 1 | 2119.88 | - | - | | zstd -1 | 73645762 | 1.044 | 2.878 | 203.05 | 224.56 | 1.23 | | zstd -3 | 66988878 | 1.761 | 3.165 | 120.38 | 127.63 | 2.47 | | zstd -5 | 65001259 | 2.563 | 3.261 | 82.71 | 86.07 | 2.86 | | zstd -10 | 60165346 | 13.242 | 3.523 | 16.01 | 16.13 | 13.22 | | zstd -15 | 58009756 | 47.601 | 3.654 | 4.45 | 4.46 | 21.61 | | zstd -19 | 54014593 | 102.835 | 3.925 | 2.06 | 2.06 | 60.15 | | zlib -1 | 77260026 | 2.895 | 2.744 | 73.23 | 75.85 | 0.27 | | zlib -3 | 72972206 | 4.116 | 2.905 | 51.50 | 52.79 | 0.27 | | zlib -6 | 68190360 | 9.633 | 3.109 | 22.01 | 22.24 | 0.27 | | zlib -9 | 67613382 | 22.554 | 3.135 | 9.40 | 9.44 | 0.27 | I benchmarked zstd decompression using the same method on the same machine. The benchmark file is located in the upstream zstd repo under `contrib/linux-kernel/zstd_decompress_test.c` [4]. The memory reported is the amount of memory required to decompress data compressed with the given compression level. If you know the maximum size of your input, you can reduce the memory usage of decompression irrespective of the compression level. | Method | Time (s) | MB/s | Adjusted MB/s | Memory (MB) | |----------|----------|---------|---------------|-------------| | none | 0.025 | 8479.54 | - | - | | zstd -1 | 0.358 | 592.15 | 636.60 | 0.84 | | zstd -3 | 0.396 | 535.32 | 571.40 | 1.46 | | zstd -5 | 0.396 | 535.32 | 571.40 | 1.46 | | zstd -10 | 0.374 | 566.81 | 607.42 | 2.51 | | zstd -15 | 0.379 | 559.34 | 598.84 | 4.61 | | zstd -19 | 0.412 | 514.54 | 547.77 | 8.80 | | zlib -1 | 0.940 | 225.52 | 231.68 | 0.04 | | zlib -3 | 0.883 | 240.08 | 247.07 | 0.04 | | zlib -6 | 0.844 | 251.17 | 258.84 | 0.04 | | zlib -9 | 0.837 | 253.27 | 287.64 | 0.04 | I ran a long series of tests and benchmarks on the btrfs side and the gains are very similar to the core benchmarks Nick ran" * 'zstd-minimal' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: squashfs: Add zstd support btrfs: Add zstd support lib: Add zstd modules lib: Add xxhash module

btrfs: remove unused BTRFS_COMPRESS_LAST

2017-08-18T14:36:29Z

We aren't using this define, so removing it. Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba

Btrfs: add skeleton code for compression heuristic

2017-08-16T14:12:04Z

Add skeleton code for compresison heuristics. Now it iterates over all the pages, but in the end always says "yes, compress please", ie it does not change the current behaviour. In the future we're going to add various heuristics to analyze the data. This patch can be used as a baseline for measuring if the effectivness and performance. Signed-off-by: Timofey Titovets Reviewed-by: David Sterba [ enhanced changelog, modified comments ] Signed-off-by: David Sterba

btrfs: Add zstd support

2017-08-15T16:02:09Z

Add zstd compression and decompression support to BtrFS. zstd at its fastest level compresses almost as well as zlib, while offering much faster compression and decompression, approaching lzo speeds. I benchmarked btrfs with zstd compression against no compression, lzo compression, and zlib compression. I benchmarked two scenarios. Copying a set of files to btrfs, and then reading the files. Copying a tarball to btrfs, extracting it to btrfs, and then reading the extracted files. After every operation, I call `sync` and include the sync time. Between every pair of operations I unmount and remount the filesystem to avoid caching. The benchmark files can be found in the upstream zstd source repository under `contrib/linux-kernel/{btrfs-benchmark.sh,btrfs-extract-benchmark.sh}` [1] [2]. I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM. The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor, 16 GB of RAM, and a SSD. The first compression benchmark is copying 10 copies of the unzipped Silesia corpus [3] into a BtrFS filesystem mounted with `-o compress-force=Method`. The decompression benchmark times how long it takes to `tar` all 10 copies into `/dev/null`. The compression ratio is measured by comparing the output of `df` and `du`. See the benchmark file [1] for details. I benchmarked multiple zstd compression levels, although the patch uses zstd level 1. | Method | Ratio | Compression MB/s | Decompression speed | |---------|-------|------------------|---------------------| | None | 0.99 | 504 | 686 | | lzo | 1.66 | 398 | 442 | | zlib | 2.58 | 65 | 241 | | zstd 1 | 2.57 | 260 | 383 | | zstd 3 | 2.71 | 174 | 408 | | zstd 6 | 2.87 | 70 | 398 | | zstd 9 | 2.92 | 43 | 406 | | zstd 12 | 2.93 | 21 | 408 | | zstd 15 | 3.01 | 11 | 354 | The next benchmark first copies `linux-4.11.6.tar` [4] to btrfs. Then it measures the compression ratio, extracts the tar, and deletes the tar. Then it measures the compression ratio again, and `tar`s the extracted files into `/dev/null`. See the benchmark file [2] for details. | Method | Tar Ratio | Extract Ratio | Copy (s) | Extract (s)| Read (s) | |--------|-----------|---------------|----------|------------|----------| | None | 0.97 | 0.78 | 0.981 | 5.501 | 8.807 | | lzo | 2.06 | 1.38 | 1.631 | 8.458 | 8.585 | | zlib | 3.40 | 1.86 | 7.750 | 21.544 | 11.744 | | zstd 1 | 3.57 | 1.85 | 2.579 | 11.479 | 9.389 | [1] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/btrfs-benchmark.sh [2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/btrfs-extract-benchmark.sh [3] http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia [4] https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.11.6.tar.xz zstd source repository: https://github.com/facebook/zstd Signed-off-by: Nick Terrell Signed-off-by: Chris Mason

Merge branch 'for-4.13-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2017-07-05T23:41:23Z

Pull btrfs updates from David Sterba: "The core updates improve error handling (mostly related to bios), with the usual incremental work on the GFP_NOFS (mis)use removal, refactoring or cleanups. Except the two top patches, all have been in for-next for an extensive amount of time. User visible changes: - statx support - quota override tunable - improved compression thresholds - obsoleted mount option alloc_start Core updates: - bio-related updates: - faster bio cloning - no allocation failures - preallocated flush bios - more kvzalloc use, memalloc_nofs protections, GFP_NOFS updates - prep work for btree_inode removal - dir-item validation - qgoup fixes and updates - cleanups: - removed unused struct members, unused code, refactoring - argument refactoring (fs_info/root, caller -> callee sink) - SEARCH_TREE ioctl docs" * 'for-4.13-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (115 commits) btrfs: Remove false alert when fiemap range is smaller than on-disk extent btrfs: Don't clear SGID when inheriting ACLs btrfs: fix integer overflow in calc_reclaim_items_nr btrfs: scrub: fix target device intialization while setting up scrub context btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges btrfs: qgroup: Introduce extent changeset for qgroup reserve functions btrfs: qgroup: Fix qgroup reserved space underflow caused by buffered write and quotas being enabled btrfs: qgroup: Return actually freed bytes for qgroup release or free data btrfs: qgroup: Cleanup btrfs_qgroup_prepare_account_extents function btrfs: qgroup: Add quick exit for non-fs extents Btrfs: rework delayed ref total_bytes_pinned accounting Btrfs: return old and new total ref mods when adding delayed refs Btrfs: always account pinned bytes when dropping a tree block ref Btrfs: update total_bytes_pinned when pinning down extents Btrfs: make BUG_ON() in add_pinned_bytes() an ASSERT() Btrfs: make add_pinned_bytes() take an s64 num_bytes instead of u64 btrfs: fix validation of XATTR_ITEM dir items btrfs: Verify dir_item in iterate_object_props btrfs: Check name_len before in btrfs_del_root_ref btrfs: Check name_len before reading btrfs_get_name ...