user/sven/linux.git/include/uapi/linux/btrfs.h, branch v4.14.92

License cleanup: add SPDX license identifier to uapi header files with a license

2017-11-02T10:20:11Z

Many user space API headers have licensing information, which is either incomplete, badly formatted or just a shorthand for referring to the license under which the file is supposed to be. This makes it hard for compliance tools to determine the correct license. Update these files with an SPDX license identifier. The identifier was chosen based on the license information in the file. GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license identifier with the added 'WITH Linux-syscall-note' exception, which is the officially assigned exception identifier for the kernel syscall exception: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". This exception makes it possible to include GPL headers into non GPL code, without confusing license compliance tools. Headers which have either explicit dual licensing or are just licensed under a non GPL license are updated with the corresponding SPDX identifier and the GPLv2 with syscall exception identifier. The format is: ((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE) SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. The update does not remove existing license information as this has to be done on a case by case basis and the copyright holders might have to be consulted. This will happen in a separate step. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

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

Btrfs: btrfs_ioctl_search_key documentation

2017-06-19T16:26:03Z

A programmer who is trying to implement calling the btrfs SEARCH or SEARCH_V2 ioctl will probably soon end up reading this struct definition. Properly document the input fields to prevent common misconceptions: 1. The search space is linear, not 3 dimensional. The invidual min/max values for objectid, type and offset cannot be used to filter the result, they only define the endpoints of an interval. 2. The transaction id (a.k.a. generation) filter applies only on transaction id of the last COW operation on a whole metadata page, not on individual items. Ad 1. The first misunderstanding was helped by the previous misleading comments on min/max type and offset: "keys returned will be >= min and <= max". Ad 2. For example, running btrfs balance will happily cause rewriting of metadata pages that contain a filesystem tree of a read only subvolume, causing transids to be increased. Also, improve descriptions of tree_id and nr_items and add in/out annotations. Signed-off-by: Hans van Kranenburg Signed-off-by: David Sterba

Btrfs: consistent usage of types in balance_args

2017-04-18T12:07:25Z

The btrfs_balance_args are only used for the balance ioctl, so use __u instead of __le here for consistency. The __le usage was introduced in bc3094673f22d and dee32d0ac3719 and was probably a result of copy/pasting when the code was written. The usage of __le did not break anything, but it's unnecessary. Also, this change makes the code less confusing for the careful reader. Signed-off-by: Hans van Kranenburg Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: remove btrfs_err_str function from uapi/linux/btrfs.h

2017-03-07T13:10:17Z

btrfs_err_str function is not called from anywhere and is replicated in the userspace headers for btrfs-progs. It's removal also fixes the following linux/btrfs.h userspace compilation error: /usr/include/linux/btrfs.h: In function 'btrfs_err_str': /usr/include/linux/btrfs.h:740:11: error: 'NULL' undeclared (first use in this function) return NULL; Suggested-by: Jeff Mahoney Signed-off-by: Dmitry V. Levin Reviewed-by: David Sterba Signed-off-by: David Sterba

Btrfs: catch invalid free space trees

2016-10-03T16:52:14Z

There are two separate issues that can lead to corrupted free space trees. 1. The free space tree bitmaps had an endianness issue on big-endian systems which is fixed by an earlier patch in this series. 2. btrfs-progs before v4.7.3 modified filesystems without updating the free space tree. To catch both of these issues at once, we need to force the free space tree to be rebuilt. To do so, add a FREE_SPACE_TREE_VALID compat_ro bit. If the bit isn't set, we know that it was either produced by a broken big-endian kernel or may have been corrupted by btrfs-progs. This also provides us with a way to add rudimentary read-write support for the free space tree to btrfs-progs: it can just clear this bit and have the kernel rebuild the free space tree. Cc: stable@vger.kernel.org # 4.5+ Tested-by: Holger Hoffstätte Tested-by: Chandan Rajendra Signed-off-by: Omar Sandoval Signed-off-by: David Sterba

Btrfs: use the correct struct for BTRFS_IOC_LOGICAL_INO

2016-07-26T11:52:25Z

BTRFS_IOC_LOGICAL_INO takes a btrfs_ioctl_logical_ino_args as argument, not a btrfs_ioctl_ino_path_args. The lines were probably copy/pasted when the code was written. Since btrfs_ioctl_logical_ino_args and btrfs_ioctl_ino_path_args have the same size, the actual IOCTL definition here does not change. But, it makes the code less confusing for the reader. Signed-off-by: Hans van Kranenburg Signed-off-by: David Sterba

btrfs: Use __u64 in exported linux/btrfs.h.

2016-05-30T11:50:02Z

This patch fixes this build error. /usr/include/linux/btrfs.h:121:3: error: unknown type name ‘u64’ u64 devid; ^~~ Fixes: 6b526ed70cf1 ("btrfs: introduce device delete by devid") Signed-off-by: Vinson Lee Signed-off-by: David Sterba

Merge branch 'foreign/jeffm/uapi' into for-chris-4.7-20160516

2016-05-16T13:46:29Z

# Conflicts: # include/uapi/linux/btrfs.h

btrfs: uapi/linux/btrfs.h migration, move struct btrfs_ioctl_defrag_range_args

2016-04-28T09:06:41Z

struct btrfs_ioctl_defrag_range_args is used by the BTRFS_IOC_DEFRAG_RANGE ioctl. Signed-off-by: Jeff Mahoney Reviewed-by: Liu Bo Reviewed-by: Josef Bacik Signed-off-by: David Sterba