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linux/fs/btrfs/compression.h

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btrfs: replace GPL boilerplate by SPDX -- headers Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Unify the include protection macros to match the file names. Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-03 19:16:55 +02:00
Btrfs: Add zlib compression support This is a large change for adding compression on reading and writing, both for inline and regular extents. It does some fairly large surgery to the writeback paths. Compression is off by default and enabled by mount -o compress. Even when the -o compress mount option is not used, it is possible to read compressed extents off the disk. If compression for a given set of pages fails to make them smaller, the file is flagged to avoid future compression attempts later. * While finding delalloc extents, the pages are locked before being sent down to the delalloc handler. This allows the delalloc handler to do complex things such as cleaning the pages, marking them writeback and starting IO on their behalf. * Inline extents are inserted at delalloc time now. This allows us to compress the data before inserting the inline extent, and it allows us to insert an inline extent that spans multiple pages. * All of the in-memory extent representations (extent_map.c, ordered-data.c etc) are changed to record both an in-memory size and an on disk size, as well as a flag for compression. From a disk format point of view, the extent pointers in the file are changed to record the on disk size of a given extent and some encoding flags. Space in the disk format is allocated for compression encoding, as well as encryption and a generic 'other' field. Neither the encryption or the 'other' field are currently used. In order to limit the amount of data read for a single random read in the file, the size of a compressed extent is limited to 128k. This is a software only limit, the disk format supports u64 sized compressed extents. In order to limit the ram consumed while processing extents, the uncompressed size of a compressed extent is limited to 256k. This is a software only limit and will be subject to tuning later. Checksumming is still done on compressed extents, and it is done on the uncompressed version of the data. This way additional encodings can be layered on without having to figure out which encoding to checksum. Compression happens at delalloc time, which is basically singled threaded because it is usually done by a single pdflush thread. This makes it tricky to spread the compression load across all the cpus on the box. We'll have to look at parallel pdflush walks of dirty inodes at a later time. Decompression is hooked into readpages and it does spread across CPUs nicely. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29 14:49:59 -04:00
btrfs: replace GPL boilerplate by SPDX -- headers Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Unify the include protection macros to match the file names. Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-03 19:16:55 +02:00
Btrfs: Add zlib compression support This is a large change for adding compression on reading and writing, both for inline and regular extents. It does some fairly large surgery to the writeback paths. Compression is off by default and enabled by mount -o compress. Even when the -o compress mount option is not used, it is possible to read compressed extents off the disk. If compression for a given set of pages fails to make them smaller, the file is flagged to avoid future compression attempts later. * While finding delalloc extents, the pages are locked before being sent down to the delalloc handler. This allows the delalloc handler to do complex things such as cleaning the pages, marking them writeback and starting IO on their behalf. * Inline extents are inserted at delalloc time now. This allows us to compress the data before inserting the inline extent, and it allows us to insert an inline extent that spans multiple pages. * All of the in-memory extent representations (extent_map.c, ordered-data.c etc) are changed to record both an in-memory size and an on disk size, as well as a flag for compression. From a disk format point of view, the extent pointers in the file are changed to record the on disk size of a given extent and some encoding flags. Space in the disk format is allocated for compression encoding, as well as encryption and a generic 'other' field. Neither the encryption or the 'other' field are currently used. In order to limit the amount of data read for a single random read in the file, the size of a compressed extent is limited to 128k. This is a software only limit, the disk format supports u64 sized compressed extents. In order to limit the ram consumed while processing extents, the uncompressed size of a compressed extent is limited to 256k. This is a software only limit and will be subject to tuning later. Checksumming is still done on compressed extents, and it is done on the uncompressed version of the data. This way additional encodings can be layered on without having to figure out which encoding to checksum. Compression happens at delalloc time, which is basically singled threaded because it is usually done by a single pdflush thread. This makes it tricky to spread the compression load across all the cpus on the box. We'll have to look at parallel pdflush walks of dirty inodes at a later time. Decompression is hooked into readpages and it does spread across CPUs nicely. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29 14:49:59 -04:00
btrfs: compression: Add linux/sizes.h for compression.h Since compression.h is using the SZ_* macros, and if some file includes only compression.h without linux/sizes.h, it will cause compile error. One example is lzo.c, if it uses BTRFS_MAX_COMPRESSED. Fix it by adding linux/sizes.h in compression.h Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-17 13:52:22 +08:00
btrfs: export compression buffer limits in a header Move the buffer limit definitions out of compress_file_range. Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14 19:30:39 +01:00
btrfs: Fix wild memory access in compression level parser [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 <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ set the default in advance ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-06 10:43:18 +08:00
btrfs: reduce arguments for decompress_bio ops struct compressed_bio pointer can be used instead. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-05-26 15:44:59 +08:00
Btrfs: add __init macro to btrfs init functions 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 <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-02 17:21:50 -06:00
btrfs: add more __cold annotations The __cold functions are placed to a special section, as they're expected to be called rarely. This could help i-cache prefetches or help compiler to decide which branches are more/less likely to be taken without any other annotations needed. Though we can't add more __exit annotations, it's still possible to add __cold (that's also added with __exit). That way the following function categories are tagged: - printf wrappers, error messages - exit helpers Signed-off-by: David Sterba <dsterba@suse.com>
2018-02-19 17:24:18 +01:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
btrfs: allow to set compression level for zlib 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 <dsterba@suse.com>
2017-09-15 17:36:57 +02:00
btrfs: merge length input and output parameter in compress_pages The length parameter is basically duplicated for input and output in the top level caller of the compress_pages chain. We can simply use one variable for that and reduce stack consumption. The compression implementation will sink the parameter to a local variable so everything works as before. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14 19:04:07 +01:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
btrfs: derive maximum output size in the compression implementation The value of max_out can be calculated from the parameters passed to the compressors, which is number of pages and the page size, and we don't have to needlessly pass it around. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14 19:45:05 +01:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
btrfs: constify buffers used by compression helpers Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14 17:58:04 +01:00
btrfs: Extract duplicate decompress code Add a common function to copy decompressed data from working buffer to bio pages. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-11-08 15:22:19 +08:00
btrfs: use bio iterators for the decompression handlers Pass the full bio to the decompression routines and use bio iterators to iterate over the data in the bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2016-11-25 09:07:46 +01:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
block: switch bios to blk_status_t Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-03 09:38:06 +02:00
Btrfs: Add zlib compression support This is a large change for adding compression on reading and writing, both for inline and regular extents. It does some fairly large surgery to the writeback paths. Compression is off by default and enabled by mount -o compress. Even when the -o compress mount option is not used, it is possible to read compressed extents off the disk. If compression for a given set of pages fails to make them smaller, the file is flagged to avoid future compression attempts later. * While finding delalloc extents, the pages are locked before being sent down to the delalloc handler. This allows the delalloc handler to do complex things such as cleaning the pages, marking them writeback and starting IO on their behalf. * Inline extents are inserted at delalloc time now. This allows us to compress the data before inserting the inline extent, and it allows us to insert an inline extent that spans multiple pages. * All of the in-memory extent representations (extent_map.c, ordered-data.c etc) are changed to record both an in-memory size and an on disk size, as well as a flag for compression. From a disk format point of view, the extent pointers in the file are changed to record the on disk size of a given extent and some encoding flags. Space in the disk format is allocated for compression encoding, as well as encryption and a generic 'other' field. Neither the encryption or the 'other' field are currently used. In order to limit the amount of data read for a single random read in the file, the size of a compressed extent is limited to 128k. This is a software only limit, the disk format supports u64 sized compressed extents. In order to limit the ram consumed while processing extents, the uncompressed size of a compressed extent is limited to 256k. This is a software only limit and will be subject to tuning later. Checksumming is still done on compressed extents, and it is done on the uncompressed version of the data. This way additional encodings can be layered on without having to figure out which encoding to checksum. Compression happens at delalloc time, which is basically singled threaded because it is usually done by a single pdflush thread. This makes it tricky to spread the compression load across all the cpus on the box. We'll have to look at parallel pdflush walks of dirty inodes at a later time. Decompression is hooked into readpages and it does spread across CPUs nicely. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29 14:49:59 -04:00
Btrfs: add write_flags for compression bio 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 <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-23 23:18:16 -06:00
block: switch bios to blk_status_t Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-03 09:38:06 +02:00
Btrfs: Add zlib compression support This is a large change for adding compression on reading and writing, both for inline and regular extents. It does some fairly large surgery to the writeback paths. Compression is off by default and enabled by mount -o compress. Even when the -o compress mount option is not used, it is possible to read compressed extents off the disk. If compression for a given set of pages fails to make them smaller, the file is flagged to avoid future compression attempts later. * While finding delalloc extents, the pages are locked before being sent down to the delalloc handler. This allows the delalloc handler to do complex things such as cleaning the pages, marking them writeback and starting IO on their behalf. * Inline extents are inserted at delalloc time now. This allows us to compress the data before inserting the inline extent, and it allows us to insert an inline extent that spans multiple pages. * All of the in-memory extent representations (extent_map.c, ordered-data.c etc) are changed to record both an in-memory size and an on disk size, as well as a flag for compression. From a disk format point of view, the extent pointers in the file are changed to record the on disk size of a given extent and some encoding flags. Space in the disk format is allocated for compression encoding, as well as encryption and a generic 'other' field. Neither the encryption or the 'other' field are currently used. In order to limit the amount of data read for a single random read in the file, the size of a compressed extent is limited to 128k. This is a software only limit, the disk format supports u64 sized compressed extents. In order to limit the ram consumed while processing extents, the uncompressed size of a compressed extent is limited to 256k. This is a software only limit and will be subject to tuning later. Checksumming is still done on compressed extents, and it is done on the uncompressed version of the data. This way additional encodings can be layered on without having to figure out which encoding to checksum. Compression happens at delalloc time, which is basically singled threaded because it is usually done by a single pdflush thread. This makes it tricky to spread the compression load across all the cpus on the box. We'll have to look at parallel pdflush walks of dirty inodes at a later time. Decompression is hooked into readpages and it does spread across CPUs nicely. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29 14:49:59 -04:00
btrfs: move btrfs_compression_type to compression.h So that its better organized. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-10 17:26:59 +08:00
btrfs: allow to set compression level for zlib 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 <dsterba@suse.com>
2017-09-15 17:36:57 +02:00
btrfs: move btrfs_compression_type to compression.h So that its better organized. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-10 17:26:59 +08:00
btrfs: Add zstd support 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 <terrelln@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2017-08-09 19:39:02 -07:00
btrfs: move btrfs_compression_type to compression.h So that its better organized. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-10 17:26:59 +08:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
btrfs: merge length input and output parameter in compress_pages The length parameter is basically duplicated for input and output in the top level caller of the compress_pages chain. We can simply use one variable for that and reduce stack consumption. The compression implementation will sink the parameter to a local variable so everything works as before. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14 19:04:07 +01:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
btrfs: derive maximum output size in the compression implementation The value of max_out can be calculated from the parameters passed to the compressors, which is number of pages and the page size, and we don't have to needlessly pass it around. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14 19:45:05 +01:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
btrfs: use bio iterators for the decompression handlers Pass the full bio to the decompression routines and use bio iterators to iterate over the data in the bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David Sterba <dsterba@suse.com>
2016-11-25 09:07:46 +01:00
btrfs: reduce arguments for decompress_bio ops struct compressed_bio pointer can be used instead. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-05-26 15:44:59 +08:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
btrfs: allow to set compression level for zlib 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 <dsterba@suse.com>
2017-09-15 17:36:57 +02:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
btrfs: constify structs with op functions or static definitions There are some op tables that can be easily made const, similarly the sysfs feature and raid tables. This is motivated by PaX CONSTIFY plugin. Signed-off-by: David Sterba <dsterba@suse.cz>
2015-01-02 18:23:10 +01:00
btrfs: Add zstd support 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 <terrelln@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2017-08-09 19:39:02 -07:00
btrfs: Allow to add new compression algorithm Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2010-12-17 14:21:50 +08:00
btrfs: compression: add helper for type to string conversion There are several places opencoding this conversion, add a helper now that we have 3 compression algorithms. Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-31 17:24:26 +01:00
Btrfs: add skeleton code for compression heuristic 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 <nefelim4ag@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> [ enhanced changelog, modified comments ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-17 16:52:58 +03:00
Btrfs: Add zlib compression support This is a large change for adding compression on reading and writing, both for inline and regular extents. It does some fairly large surgery to the writeback paths. Compression is off by default and enabled by mount -o compress. Even when the -o compress mount option is not used, it is possible to read compressed extents off the disk. If compression for a given set of pages fails to make them smaller, the file is flagged to avoid future compression attempts later. * While finding delalloc extents, the pages are locked before being sent down to the delalloc handler. This allows the delalloc handler to do complex things such as cleaning the pages, marking them writeback and starting IO on their behalf. * Inline extents are inserted at delalloc time now. This allows us to compress the data before inserting the inline extent, and it allows us to insert an inline extent that spans multiple pages. * All of the in-memory extent representations (extent_map.c, ordered-data.c etc) are changed to record both an in-memory size and an on disk size, as well as a flag for compression. From a disk format point of view, the extent pointers in the file are changed to record the on disk size of a given extent and some encoding flags. Space in the disk format is allocated for compression encoding, as well as encryption and a generic 'other' field. Neither the encryption or the 'other' field are currently used. In order to limit the amount of data read for a single random read in the file, the size of a compressed extent is limited to 128k. This is a software only limit, the disk format supports u64 sized compressed extents. In order to limit the ram consumed while processing extents, the uncompressed size of a compressed extent is limited to 256k. This is a software only limit and will be subject to tuning later. Checksumming is still done on compressed extents, and it is done on the uncompressed version of the data. This way additional encodings can be layered on without having to figure out which encoding to checksum. Compression happens at delalloc time, which is basically singled threaded because it is usually done by a single pdflush thread. This makes it tricky to spread the compression load across all the cpus on the box. We'll have to look at parallel pdflush walks of dirty inodes at a later time. Decompression is hooked into readpages and it does spread across CPUs nicely. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29 14:49:59 -04:00