<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/git/stable/linux.git/fs/btrfs/Makefile, branch linux-5.9.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<id>https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=linux-5.9.y</id>
<link rel='self' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=linux-5.9.y'/>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/'/>
<updated>2020-03-23T16:01:54+00:00</updated>
<entry>
<title>Btrfs: move all reflink implementation code into its own file</title>
<updated>2020-03-23T16:01:54+00:00</updated>
<author>
<name>Filipe Manana</name>
<email>fdmanana@suse.com</email>
</author>
<published>2020-02-28T13:04:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6a177381007b463ad611375cce526c24f12ab081'/>
<id>urn:sha1:6a177381007b463ad611375cce526c24f12ab081</id>
<content type='text'>
The reflink code is quite large and has been living in ioctl.c since ever.
It has grown over the years after many bug fixes and improvements, and
since I'm planning on making some further improvements on it, it's time
to get it better organized by moving into its own file, reflink.c
(similar to what xfs does for example).

This change only moves the code out of ioctl.c into the new file, it
doesn't do any other change.

Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
</content>
</entry>
<entry>
<title>btrfs: add the beginning of async discard, discard workqueue</title>
<updated>2020-01-20T15:40:57+00:00</updated>
<author>
<name>Dennis Zhou</name>
<email>dennis@kernel.org</email>
</author>
<published>2019-12-14T00:22:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b0643e59cfa609c4b5f246f2b2c33b078f87e9d9'/>
<id>urn:sha1:b0643e59cfa609c4b5f246f2b2c33b078f87e9d9</id>
<content type='text'>
When discard is enabled, everytime a pinned extent is released back to
the block_group's free space cache, a discard is issued for the extent.
This is an overeager approach when it comes to discarding and helping
the SSD maintain enough free space to prevent severe garbage collection
situations.

This adds the beginning of async discard. Instead of issuing a discard
prior to returning it to the free space, it is just marked as untrimmed.
The block_group is then added to a LRU which then feeds into a workqueue
to issue discards at a much slower rate. Full discarding of unused block
groups is still done and will be addressed in a future patch of the
series.

For now, we don't persist the discard state of extents and bitmaps.
Therefore, our failure recovery mode will be to consider extents
untrimmed. This lets us handle failure and unmounting as one in the
same.

On a number of Facebook webservers, I collected data every minute
accounting the time we spent in btrfs_finish_extent_commit() (col. 1)
and in btrfs_commit_transaction() (col. 2). btrfs_finish_extent_commit()
is where we discard extents synchronously before returning them to the
free space cache.

discard=sync:
                 p99 total per minute       p99 total per minute
      Drive   |   extent_commit() (ms)  |    commit_trans() (ms)
    ---------------------------------------------------------------
     Drive A  |           434           |          1170
     Drive B  |           880           |          2330
     Drive C  |          2943           |          3920
     Drive D  |          4763           |          5701

discard=async:
                 p99 total per minute       p99 total per minute
      Drive   |   extent_commit() (ms)  |    commit_trans() (ms)
    --------------------------------------------------------------
     Drive A  |           134           |           956
     Drive B  |            64           |          1972
     Drive C  |            59           |          1032
     Drive D  |            62           |          1200

While it's not great that the stats are cumulative over 1m, all of these
servers are running the same workload and and the delta between the two
are substantial. We are spending significantly less time in
btrfs_finish_extent_commit() which is responsible for discarding.

Reviewed-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: Dennis Zhou &lt;dennis@kernel.org&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
</content>
</entry>
<entry>
<title>btrfs: migrate the block group lookup code</title>
<updated>2019-09-09T12:59:04+00:00</updated>
<author>
<name>Josef Bacik</name>
<email>josef@toxicpanda.com</email>
</author>
<published>2019-06-20T19:37:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2e405ad842546a1a37aaa586d5140d071cb1f802'/>
<id>urn:sha1:2e405ad842546a1a37aaa586d5140d071cb1f802</id>
<content type='text'>
Move these bits first as they are the easiest to move.  Export two of
the helpers so they can be moved all at once.

Signed-off-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Reviewed-by: David Sterba &lt;dsterba@suse.com&gt;
[ minor style updates ]
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
</content>
</entry>
<entry>
<title>btrfs: migrate the delalloc space stuff to it's own home</title>
<updated>2019-07-04T15:26:17+00:00</updated>
<author>
<name>Josef Bacik</name>
<email>josef@toxicpanda.com</email>
</author>
<published>2019-06-19T19:12:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=867363429d706984915cb4b1f299ce05f8413e23'/>
<id>urn:sha1:867363429d706984915cb4b1f299ce05f8413e23</id>
<content type='text'>
We have code for data and metadata reservations for delalloc.  There's
quite a bit of code here, and it's used in a lot of places so I've
separated it out to it's own file.  inode.c and file.c are already
pretty large, and this code is complicated enough to live in its own
space.

Signed-off-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
</content>
</entry>
<entry>
<title>btrfs: migrate the block-rsv code to block-rsv.c</title>
<updated>2019-07-02T10:30:54+00:00</updated>
<author>
<name>Josef Bacik</name>
<email>josef@toxicpanda.com</email>
</author>
<published>2019-06-19T17:47:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=550fa228ee7ebea3c3499897a7aef6536de73fff'/>
<id>urn:sha1:550fa228ee7ebea3c3499897a7aef6536de73fff</id>
<content type='text'>
This moves everything out of extent-tree.c to block-rsv.c.

Signed-off-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
</content>
</entry>
<entry>
<title>btrfs: move the space_info handling code to space-info.c</title>
<updated>2019-07-02T10:30:52+00:00</updated>
<author>
<name>Josef Bacik</name>
<email>josef@toxicpanda.com</email>
</author>
<published>2019-06-18T20:09:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=280c290881bc048bd5dbe02796173f55ca86e697'/>
<id>urn:sha1:280c290881bc048bd5dbe02796173f55ca86e697</id>
<content type='text'>
These are the basic init and lookup functions and some helper functions,
fairly straightforward before the bad stuff starts.

Reviewed-by: Nikolay Borisov &lt;nborisov@suse.com&gt;
Signed-off-by: Josef Bacik &lt;josef@toxicpanda.com&gt;
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>Btrfs: add extent map selftests</title>
<updated>2018-01-22T15:08:22+00:00</updated>
<author>
<name>Liu Bo</name>
<email>bo.li.liu@oracle.com</email>
</author>
<published>2018-01-05T19:51:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=72b28077a20a6a1f14494602466c219241f45d89'/>
<id>urn:sha1:72b28077a20a6a1f14494602466c219241f45d89</id>
<content type='text'>
We've observed that btrfs_get_extent() and merge_extent_mapping() could
return -EEXIST in several cases, and they are caused by some racy
condition, e.g dio read vs dio write, which makes the problem very tricky
to reproduce.

This adds extent map selftests in order to simulate those racy situations.

Signed-off-by: Liu Bo &lt;bo.li.liu@oracle.com&gt;
Reviewed-by: Josef Bacik &lt;jbacik@fb.com&gt;
[ minor string adjustments ]
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux</title>
<updated>2017-11-14T21:35:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-11-14T21:35:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5cea7647e64657138138a3794ae172ee0fc175da'/>
<id>urn:sha1:5cea7647e64657138138a3794ae172ee0fc175da</id>
<content type='text'>
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
  ...
</content>
</entry>
<entry>
<title>License cleanup: add SPDX GPL-2.0 license identifier to files with no license</title>
<updated>2017-11-02T10:10:55+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-11-01T14:07:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b24413180f5600bcb3bb70fbed5cf186b60864bd'/>
<id>urn:sha1:b24413180f5600bcb3bb70fbed5cf186b60864bd</id>
<content type='text'>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode &amp; Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained &gt;5
   lines of source
 - File already had some variant of a license header in it (even if &lt;5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart &lt;kstewart@linuxfoundation.org&gt;
Reviewed-by: Philippe Ombredanne &lt;pombredanne@nexb.com&gt;
Reviewed-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
