<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/git/stable/linux.git/fs/btrfs/Kconfig, branch linux-5.2.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<id>https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=linux-5.2.y</id>
<link rel='self' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=linux-5.2.y'/>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/'/>
<updated>2018-04-12T14:29:55+00:00</updated>
<entry>
<title>btrfs: add SPDX header to Kconfig</title>
<updated>2018-04-12T14:29:55+00:00</updated>
<author>
<name>David Sterba</name>
<email>dsterba@suse.com</email>
</author>
<published>2018-04-03T17:23:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=852eb3aeeaf65f175f15c7af6a31aeffc050d659'/>
<id>urn:sha1:852eb3aeeaf65f175f15c7af6a31aeffc050d659</id>
<content type='text'>
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
</content>
</entry>
<entry>
<title>btrfs: Remove custom crc32c init code</title>
<updated>2018-03-26T13:09:39+00:00</updated>
<author>
<name>Nikolay Borisov</name>
<email>nborisov@suse.com</email>
</author>
<published>2018-01-08T09:45:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9678c54388b6a6b309ff7ee5c8d23fa9eba7c06f'/>
<id>urn:sha1:9678c54388b6a6b309ff7ee5c8d23fa9eba7c06f</id>
<content type='text'>
The custom crc32 init code was introduced in
14a958e678cd ("Btrfs: fix btrfs boot when compiled as built-in") to
enable using btrfs as a built-in. However, later as pointed out by
60efa5eb2e88 ("Btrfs: use late_initcall instead of module_init") this
wasn't enough and finally btrfs was switched to late_initcall which
comes after the generic crc32c implementation is initiliased. The
latter commit superseeded the former. Now that we don't have to
maintain our own code let's just remove it and switch to using the
generic implementation.

Despite touching a lot of files the patch is really simple. Here is the gist of
the changes:

1. Select LIBCRC32C rather than the low-level modules.
2. s/btrfs_crc32c/crc32c/g
3. replace hash.h with linux/crc32c.h
4. Move the btrfs namehash funcs to ctree.h and change the tree accordingly.

I've tested this with btrfs being both a module and a built-in and xfstest
doesn't complain.

Does seem to fix the longstanding problem of not automatically selectiong
the crc32c module when btrfs is used. Possibly there is a workaround in
dracut.

The modinfo confirms that now all the module dependencies are there:

before:
depends:        zstd_compress,zstd_decompress,raid6_pq,xor,zlib_deflate

after:
depends:        libcrc32c,zstd_compress,zstd_decompress,raid6_pq,xor,zlib_deflate

Signed-off-by: Nikolay Borisov &lt;nborisov@suse.com&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
[ add more info to changelog from mails ]
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
</content>
</entry>
<entry>
<title>fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at</title>
<updated>2018-01-01T19:45:37+00:00</updated>
<author>
<name>Adam Borowski</name>
<email>kilobyte@angband.pl</email>
</author>
<published>2017-12-20T13:58:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=91581e4c60db35268ad67c550f5c551045f592f5'/>
<id>urn:sha1:91581e4c60db35268ad67c550f5c551045f592f5</id>
<content type='text'>
This link is replicated in most filesystems' config stanzas.  Referring
to an archived version of that site is pointless as it mostly deals with
patches; user documentation is available elsewhere.

Signed-off-by: Adam Borowski &lt;kilobyte@angband.pl&gt;
CC: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Reviewed-by: Darrick J. Wong &lt;darrick.wong@oracle.com&gt;
Acked-by: Jan Kara &lt;jack@suse.cz&gt;
Acked-by: Dave Kleikamp &lt;dave.kleikamp@oracle.com&gt;
Acked-by: David Sterba &lt;dsterba@suse.com&gt;
Acked-by: "Yan, Zheng" &lt;zyan@redhat.com&gt;
Acked-by: Chao Yu &lt;yuchao0@huawei.com&gt;
Acked-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
Acked-by: Steve French &lt;smfrench@gmail.com&gt;
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
</content>
</entry>
<entry>
<title>Btrfs: add a extent ref verify tool</title>
<updated>2017-10-30T11:28:00+00:00</updated>
<author>
<name>Josef Bacik</name>
<email>josef@toxicpanda.com</email>
</author>
<published>2017-09-29T19:43:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fd708b81d972a0714b02a60eb4792fdbf15868c4'/>
<id>urn:sha1:fd708b81d972a0714b02a60eb4792fdbf15868c4</id>
<content type='text'>
We were having corruption issues that were tied back to problems with
the extent tree.  In order to track them down I built this tool to try
and find the culprit, which was pretty successful.  If you compile with
this tool on it will live verify every ref update that the fs makes and
make sure it is consistent and valid.  I've run this through with
xfstests and haven't gotten any false positives.  Thanks,

Signed-off-by: Josef Bacik &lt;jbacik@fb.com&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
[ update error messages, add fixup from Dan Carpenter to handle errors
  of read_tree_block ]
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
</content>
</entry>
<entry>
<title>btrfs: Add zstd support</title>
<updated>2017-08-15T16:02:09+00:00</updated>
<author>
<name>Nick Terrell</name>
<email>terrelln@fb.com</email>
</author>
<published>2017-08-10T02:39:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5c1aab1dd5445ed8bdcdbb575abc1b0d7ee5b2e7'/>
<id>urn:sha1:5c1aab1dd5445ed8bdcdbb575abc1b0d7ee5b2e7</id>
<content type='text'>
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 &lt;terrelln@fb.com&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</content>
</entry>
<entry>
<title>rcu: Make SRCU optional by using CONFIG_SRCU</title>
<updated>2015-01-06T19:04:29+00:00</updated>
<author>
<name>Pranith Kumar</name>
<email>bobby.prani@gmail.com</email>
</author>
<published>2014-12-05T16:24:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=83fe27ea531161a655f02dc7732d14cfaa27fd5d'/>
<id>urn:sha1:83fe27ea531161a655f02dc7732d14cfaa27fd5d</id>
<content type='text'>
SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.

The current patch tries to make compiling SRCU optional by introducing a new
Kconfig option CONFIG_SRCU which is selected when any of the components making
use of SRCU are selected.

If we do not select CONFIG_SRCU, srcu.o will not be compiled at all.

   text    data     bss     dec     hex filename
   2007       0       0    2007     7d7 kernel/rcu/srcu.o

Size of arch/powerpc/boot/zImage changes from

   text    data     bss     dec     hex filename
 831552   64180   23944  919676   e087c arch/powerpc/boot/zImage : before
 829504   64180   23952  917636   e0084 arch/powerpc/boot/zImage : after

so the savings are about ~2000 bytes.

Signed-off-by: Pranith Kumar &lt;bobby.prani@gmail.com&gt;
CC: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
CC: Josh Triplett &lt;josh@joshtriplett.org&gt;
CC: Lai Jiangshan &lt;laijs@cn.fujitsu.com&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
[ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]
</content>
</entry>
<entry>
<title>Btrfs: fix btrfs boot when compiled as built-in</title>
<updated>2014-01-28T21:20:31+00:00</updated>
<author>
<name>Filipe David Borba Manana</name>
<email>fdmanana@gmail.com</email>
</author>
<published>2014-01-12T02:22:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=14a958e678cd77cae475b60ca46c0797b1c006a1'/>
<id>urn:sha1:14a958e678cd77cae475b60ca46c0797b1c006a1</id>
<content type='text'>
After the change titled "Btrfs: add support for inode properties", if
btrfs was built-in the kernel (i.e. not as a module), it would cause a
kernel panic, as reported recently by Fengguang:

[    2.024722] BUG: unable to handle kernel NULL pointer dereference at           (null)
[    2.027814] IP: [&lt;ffffffff81501594&gt;] crc32c+0xc/0x6b
[    2.028684] PGD 0
[    2.028684] Oops: 0000 [#1] SMP
[    2.028684] Modules linked in:
[    2.028684] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-rc7-04795-ga7b57c2 #1
[    2.028684] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    2.028684] task: ffff88000edba100 ti: ffff88000edd6000 task.ti: ffff88000edd6000
[    2.028684] RIP: 0010:[&lt;ffffffff81501594&gt;]  [&lt;ffffffff81501594&gt;] crc32c+0xc/0x6b
[    2.028684] RSP: 0000:ffff88000edd7e58  EFLAGS: 00010246
[    2.028684] RAX: 0000000000000000 RBX: ffffffff82295550 RCX: 0000000000000000
[    2.028684] RDX: 0000000000000011 RSI: ffffffff81efe393 RDI: 00000000fffffffe
[    2.028684] RBP: ffff88000edd7e60 R08: 0000000000000003 R09: 0000000000015d20
[    2.028684] R10: ffffffff81ef225e R11: ffffffff811b0222 R12: ffffffffffffffff
[    2.028684] R13: 0000000000000239 R14: 0000000000000000 R15: 0000000000000000
[    2.028684] FS:  0000000000000000(0000) GS:ffff88000fa00000(0000) knlGS:0000000000000000
[    2.028684] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[    2.028684] CR2: 0000000000000000 CR3: 000000000220c000 CR4: 00000000000006f0
[    2.028684] Stack:
[    2.028684]  ffffffff82295550 ffff88000edd7e80 ffffffff8238af62 ffffffff8238ac05
[    2.028684]  0000000000000000 ffff88000edd7e98 ffffffff8238ac0f ffffffff8238ac05
[    2.028684]  ffff88000edd7f08 ffffffff810002ba ffff88000edd7f00 ffffffff810e2404
[    2.028684] Call Trace:
[    2.028684]  [&lt;ffffffff8238af62&gt;] btrfs_props_init+0x4f/0x96
[    2.028684]  [&lt;ffffffff8238ac05&gt;] ? ftrace_define_fields_btrfs_space_reservation+0x145/0x145
[    2.028684]  [&lt;ffffffff8238ac0f&gt;] init_btrfs_fs+0xa/0xf0
[    2.028684]  [&lt;ffffffff8238ac05&gt;] ? ftrace_define_fields_btrfs_space_reservation+0x145/0x145
[    2.028684]  [&lt;ffffffff810002ba&gt;] do_one_initcall+0xa4/0x13a
[    2.028684]  [&lt;ffffffff810e2404&gt;] ? parse_args+0x25f/0x33d
[    2.028684]  [&lt;ffffffff8234cf75&gt;] kernel_init_freeable+0x1aa/0x230
[    2.028684]  [&lt;ffffffff8234c785&gt;] ? do_early_param+0x88/0x88
[    2.028684]  [&lt;ffffffff819f61b5&gt;] ? rest_init+0x89/0x89
[    2.028684]  [&lt;ffffffff819f61c3&gt;] kernel_init+0xe/0x109

The issue here is that the initialization function of btrfs (super.c:init_btrfs_fs)
started using crc32c (from lib/libcrc32c.c). But when it needs to call crc32c (as
part of the properties initialization routine), the libcrc32c is not yet initialized,
so crc32c derreferenced a NULL pointer (lib/libcrc32c.c:tfm), causing the kernel
panic on boot.

The approach to fix this is to use crypto component directly to use its crc32c (which
is basically what lib/libcrc32c.c is, a wrapper around crypto). This is what ext4 is
doing as well, it uses crypto directly to get crc32c functionality.

Verified this works both when btrfs is built-in and when it's loadable kernel module.

Signed-off-by: Filipe David Borba Manana &lt;fdmanana@gmail.com&gt;
Signed-off-by: Josef Bacik &lt;jbacik@fb.com&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs</title>
<updated>2013-11-22T16:38:55+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-11-22T16:38:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fb0d1eb8925daaabc45ef67be740a41f49303d07'/>
<id>urn:sha1:fb0d1eb8925daaabc45ef67be740a41f49303d07</id>
<content type='text'>
Pull btrfs fixes from Chris Mason:
 "Almost all of these are bug fixes.  Dave Sterba's documentation update
  is the big exception because he removed our promises to set any
  machine running Btrfs on fire"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Documentation: filesystems: update btrfs tools section
  Documentation: filesystems: add new btrfs mount options
  btrfs: update kconfig help text
  btrfs: fix bio_size_ok() for max_sectors &gt; 0xffff
  btrfs: Use trace condition for get_extent tracepoint
  btrfs: fix typo in the log message
  Btrfs: fix list delete warning when removing ordered root from the list
  Btrfs: print bytenr instead of page pointer in check-int
  Btrfs: remove dead codes from ctree.h
  Btrfs: don't wait for ordered data outside desired range
  Btrfs: fix lockdep error in async commit
  Btrfs: avoid heavy operations in btrfs_commit_super
  Btrfs: fix __btrfs_start_workers retval
  Btrfs: disable online raid-repair on ro mounts
  Btrfs: do not inc uncorrectable_errors counter on ro scrubs
  Btrfs: only drop modified extents if we logged the whole inode
  Btrfs: make sure to copy everything if we rename
  Btrfs: don't BUG_ON() if we get an error walking backrefs
</content>
</entry>
<entry>
<title>btrfs: update kconfig help text</title>
<updated>2013-11-21T01:49:09+00:00</updated>
<author>
<name>David Sterba</name>
<email>dsterba@suse.cz</email>
</author>
<published>2013-11-20T13:32:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4204617d142c0887e45fda2562cb5c58097b918e'/>
<id>urn:sha1:4204617d142c0887e45fda2562cb5c58097b918e</id>
<content type='text'>
Reflect the current status. Portions of the text taken from the
wiki pages.

Signed-off-by: David Sterba &lt;dsterba@suse.cz&gt;
Signed-off-by: Chris Mason &lt;chris.mason@fusionio.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial</title>
<updated>2013-11-16T00:47:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-11-16T00:47:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9073e1a804c3096eda84ee7cbf11d1f174236c75'/>
<id>urn:sha1:9073e1a804c3096eda84ee7cbf11d1f174236c75</id>
<content type='text'>
Pull trivial tree updates from Jiri Kosina:
 "Usual earth-shaking, news-breaking, rocket science pile from
  trivial.git"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits)
  doc: usb: Fix typo in Documentation/usb/gadget_configs.txt
  doc: add missing files to timers/00-INDEX
  timekeeping: Fix some trivial typos in comments
  mm: Fix some trivial typos in comments
  irq: Fix some trivial typos in comments
  NUMA: fix typos in Kconfig help text
  mm: update 00-INDEX
  doc: Documentation/DMA-attributes.txt fix typo
  DRM: comment: `halve' -&gt; `half'
  Docs: Kconfig: `devlopers' -&gt; `developers'
  doc: typo on word accounting in kprobes.c in mutliple architectures
  treewide: fix "usefull" typo
  treewide: fix "distingush" typo
  mm/Kconfig: Grammar s/an/a/
  kexec: Typo s/the/then/
  Documentation/kvm: Update cpuid documentation for steal time and pv eoi
  treewide: Fix common typo in "identify"
  __page_to_pfn: Fix typo in comment
  Correct some typos for word frequency
  clk: fixed-factor: Fix a trivial typo
  ...
</content>
</entry>
</feed>
