<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/fs/btrfs/xattr.c, branch v4.2.3</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs</title>
<updated>2015-04-27T00:22:07+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-04-26T22:48:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9ec3a646fe09970f801ab15e0f1694060b9f19af'/>
<id>9ec3a646fe09970f801ab15e0f1694060b9f19af</id>
<content type='text'>
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode-&gt;i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some -&gt;d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode-&gt;i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some -&gt;d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
</pre>
</div>
</content>
</entry>
<entry>
<title>VFS: normal filesystems (and lustre): d_inode() annotations</title>
<updated>2015-04-15T19:06:57+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2015-03-17T22:25:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2b0143b5c986be1ce8408b3aadc4709e0a94429d'/>
<id>2b0143b5c986be1ce8408b3aadc4709e0a94429d</id>
<content type='text'>
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: don't accept bare namespace as a valid xattr</title>
<updated>2015-03-27T01:10:24+00:00</updated>
<author>
<name>David Sterba</name>
<email>dsterba@suse.cz</email>
</author>
<published>2015-03-25T18:26:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3c3b04d10ff1811a27f86684ccd2f5ba6983211d'/>
<id>3c3b04d10ff1811a27f86684ccd2f5ba6983211d</id>
<content type='text'>
Due to insufficient check in btrfs_is_valid_xattr, this unexpectedly
works:

 $ touch file
 $ setfattr -n user. -v 1 file
 $ getfattr -d file
user.="1"

ie. the missing attribute name after the namespace.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=94291
Reported-by: William Douglas &lt;william.douglas@intel.com&gt;
CC: &lt;stable@vger.kernel.org&gt; # 2.6.29+
Signed-off-by: David Sterba &lt;dsterba@suse.cz&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Due to insufficient check in btrfs_is_valid_xattr, this unexpectedly
works:

 $ touch file
 $ setfattr -n user. -v 1 file
 $ getfattr -d file
user.="1"

ie. the missing attribute name after the namespace.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=94291
Reported-by: William Douglas &lt;william.douglas@intel.com&gt;
CC: &lt;stable@vger.kernel.org&gt; # 2.6.29+
Signed-off-by: David Sterba &lt;dsterba@suse.cz&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Btrfs: do not ignore errors from btrfs_lookup_xattr in do_setxattr</title>
<updated>2015-03-02T22:04:45+00:00</updated>
<author>
<name>Filipe Manana</name>
<email>fdmanana@suse.com</email>
</author>
<published>2015-02-23T19:50:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5cdf83edb8e41cad1ec8eab2d402b4f9d9eb7ee0'/>
<id>5cdf83edb8e41cad1ec8eab2d402b4f9d9eb7ee0</id>
<content type='text'>
The return value from btrfs_lookup_xattr() can be a pointer encoding an
error, therefore deal with it. This fixes commit 5f5bc6b1e2d5
("Btrfs: make xattr replace operations atomic").

Signed-off-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The return value from btrfs_lookup_xattr() can be a pointer encoding an
error, therefore deal with it. This fixes commit 5f5bc6b1e2d5
("Btrfs: make xattr replace operations atomic").

Signed-off-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Btrfs: make xattr replace operations atomic</title>
<updated>2014-11-21T01:20:07+00:00</updated>
<author>
<name>Filipe Manana</name>
<email>fdmanana@suse.com</email>
</author>
<published>2014-11-09T08:38:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5f5bc6b1e2d5a6f827bc860ef2dc5b6f365d1339'/>
<id>5f5bc6b1e2d5a6f827bc860ef2dc5b6f365d1339</id>
<content type='text'>
Replacing a xattr consists of doing a lookup for its existing value, delete
the current value from the respective leaf, release the search path and then
finally insert the new value. This leaves a time window where readers (getxattr,
listxattrs) won't see any value for the xattr. Xattrs are used to store ACLs,
so this has security implications.

This change also fixes 2 other existing issues which were:

*) Deleting the old xattr value without verifying first if the new xattr will
   fit in the existing leaf item (in case multiple xattrs are packed in the
   same item due to name hash collision);

*) Returning -EEXIST when the flag XATTR_CREATE is given and the xattr doesn't
   exist but we have have an existing item that packs muliple xattrs with
   the same name hash as the input xattr. In this case we should return ENOSPC.

A test case for xfstests follows soon.

Thanks to Alexandre Oliva for reporting the non-atomicity of the xattr replace
implementation.

Reported-by: Alexandre Oliva &lt;oliva@gnu.org&gt;
Signed-off-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Replacing a xattr consists of doing a lookup for its existing value, delete
the current value from the respective leaf, release the search path and then
finally insert the new value. This leaves a time window where readers (getxattr,
listxattrs) won't see any value for the xattr. Xattrs are used to store ACLs,
so this has security implications.

This change also fixes 2 other existing issues which were:

*) Deleting the old xattr value without verifying first if the new xattr will
   fit in the existing leaf item (in case multiple xattrs are packed in the
   same item due to name hash collision);

*) Returning -EEXIST when the flag XATTR_CREATE is given and the xattr doesn't
   exist but we have have an existing item that packs muliple xattrs with
   the same name hash as the input xattr. In this case we should return ENOSPC.

A test case for xfstests follows soon.

Thanks to Alexandre Oliva for reporting the non-atomicity of the xattr replace
implementation.

Reported-by: Alexandre Oliva &lt;oliva@gnu.org&gt;
Signed-off-by: Filipe Manana &lt;fdmanana@suse.com&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: kill the key type accessor helpers</title>
<updated>2014-09-17T20:37:12+00:00</updated>
<author>
<name>David Sterba</name>
<email>dsterba@suse.cz</email>
</author>
<published>2014-06-04T16:41:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=962a298f35110edd8f326814ae41a3dd306ecb64'/>
<id>962a298f35110edd8f326814ae41a3dd306ecb64</id>
<content type='text'>
btrfs_set_key_type and btrfs_key_type are used inconsistently along with
open coded variants. Other members of btrfs_key are accessed directly
without any helpers anyway.

Signed-off-by: David Sterba &lt;dsterba@suse.cz&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
btrfs_set_key_type and btrfs_key_type are used inconsistently along with
open coded variants. Other members of btrfs_key are accessed directly
without any helpers anyway.

Signed-off-by: David Sterba &lt;dsterba@suse.cz&gt;
Signed-off-by: Chris Mason &lt;clm@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs</title>
<updated>2014-01-31T04:08:20+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-01-31T04:08:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e7651b819e90da924991d727d3c007200a18670d'/>
<id>e7651b819e90da924991d727d3c007200a18670d</id>
<content type='text'>
Pull btrfs updates from Chris Mason:
 "This is a pretty big pull, and most of these changes have been
  floating in btrfs-next for a long time.  Filipe's properties work is a
  cool building block for inheriting attributes like compression down on
  a per inode basis.

  Jeff Mahoney kicked in code to export filesystem info into sysfs.

  Otherwise, lots of performance improvements, cleanups and bug fixes.

  Looks like there are still a few other small pending incrementals, but
  I wanted to get the bulk of this in first"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (149 commits)
  Btrfs: fix spin_unlock in check_ref_cleanup
  Btrfs: setup inode location during btrfs_init_inode_locked
  Btrfs: don't use ram_bytes for uncompressed inline items
  Btrfs: fix btrfs_search_slot_for_read backwards iteration
  Btrfs: do not export ulist functions
  Btrfs: rework ulist with list+rb_tree
  Btrfs: fix memory leaks on walking backrefs failure
  Btrfs: fix send file hole detection leading to data corruption
  Btrfs: add a reschedule point in btrfs_find_all_roots()
  Btrfs: make send's file extent item search more efficient
  Btrfs: fix to catch all errors when resolving indirect ref
  Btrfs: fix protection between walking backrefs and root deletion
  btrfs: fix warning while merging two adjacent extents
  Btrfs: fix infinite path build loops in incremental send
  btrfs: undo sysfs when open_ctree() fails
  Btrfs: fix snprintf usage by send's gen_unique_name
  btrfs: fix defrag 32-bit integer overflow
  btrfs: sysfs: list the NO_HOLES feature
  btrfs: sysfs: don't show reserved incompat feature
  btrfs: call permission checks earlier in ioctls and return EPERM
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull btrfs updates from Chris Mason:
 "This is a pretty big pull, and most of these changes have been
  floating in btrfs-next for a long time.  Filipe's properties work is a
  cool building block for inheriting attributes like compression down on
  a per inode basis.

  Jeff Mahoney kicked in code to export filesystem info into sysfs.

  Otherwise, lots of performance improvements, cleanups and bug fixes.

  Looks like there are still a few other small pending incrementals, but
  I wanted to get the bulk of this in first"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (149 commits)
  Btrfs: fix spin_unlock in check_ref_cleanup
  Btrfs: setup inode location during btrfs_init_inode_locked
  Btrfs: don't use ram_bytes for uncompressed inline items
  Btrfs: fix btrfs_search_slot_for_read backwards iteration
  Btrfs: do not export ulist functions
  Btrfs: rework ulist with list+rb_tree
  Btrfs: fix memory leaks on walking backrefs failure
  Btrfs: fix send file hole detection leading to data corruption
  Btrfs: add a reschedule point in btrfs_find_all_roots()
  Btrfs: make send's file extent item search more efficient
  Btrfs: fix to catch all errors when resolving indirect ref
  Btrfs: fix protection between walking backrefs and root deletion
  btrfs: fix warning while merging two adjacent extents
  Btrfs: fix infinite path build loops in incremental send
  btrfs: undo sysfs when open_ctree() fails
  Btrfs: fix snprintf usage by send's gen_unique_name
  btrfs: fix defrag 32-bit integer overflow
  btrfs: sysfs: list the NO_HOLES feature
  btrfs: sysfs: don't show reserved incompat feature
  btrfs: call permission checks earlier in ioctls and return EPERM
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Btrfs: add support for inode properties</title>
<updated>2014-01-28T21:20:24+00:00</updated>
<author>
<name>Filipe David Borba Manana</name>
<email>fdmanana@gmail.com</email>
</author>
<published>2014-01-07T11:47:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=63541927c8d11d2686778b1e8ec71c14b4fd53e4'/>
<id>63541927c8d11d2686778b1e8ec71c14b4fd53e4</id>
<content type='text'>
This change adds infrastructure to allow for generic properties for
inodes. Properties are name/value pairs that can be associated with
inodes for different purposes. They are stored as xattrs with the
prefix "btrfs."

Properties can be inherited - this means when a directory inode has
inheritable properties set, these are added to new inodes created
under that directory. Further, subvolumes can also have properties
associated with them, and they can be inherited from their parent
subvolume. Naturally, directory properties have priority over subvolume
properties (in practice a subvolume property is just a regular
property associated with the root inode, objectid 256, of the
subvolume's fs tree).

This change also adds one specific property implementation, named
"compression", whose values can be "lzo" or "zlib" and it's an
inheritable property.

The corresponding changes to btrfs-progs were also implemented.
A patch with xfstests for this feature will follow once there's
agreement on this change/feature.

Further, the script at the bottom of this commit message was used to
do some benchmarks to measure any performance penalties of this feature.

Basically the tests correspond to:

Test 1 - create a filesystem and mount it with compress-force=lzo,
then sequentially create N files of 64Kb each, measure how long it took
to create the files, unmount the filesystem, mount the filesystem and
perform an 'ls -lha' against the test directory holding the N files, and
report the time the command took.

Test 2 - create a filesystem and don't use any compression option when
mounting it - instead set the compression property of the subvolume's
root to 'lzo'. Then create N files of 64Kb, and report the time it took.
The unmount the filesystem, mount it again and perform an 'ls -lha' like
in the former test. This means every single file ends up with a property
(xattr) associated to it.

Test 3 - same as test 2, but uses 4 properties - 3 are duplicates of the
compression property, have no real effect other than adding more work
when inheriting properties and taking more btree leaf space.

Test 4 - same as test 3 but with 10 properties per file.

Results (in seconds, and averages of 5 runs each), for different N
numbers of files follow.

* Without properties (test 1)

                    file creation time        ls -lha time
10 000 files              3.49                   0.76
100 000 files            47.19                   8.37
1 000 000 files         518.51                 107.06

* With 1 property (compression property set to lzo - test 2)

                    file creation time        ls -lha time
10 000 files              3.63                    0.93
100 000 files            48.56                    9.74
1 000 000 files         537.72                  125.11

* With 4 properties (test 3)

                    file creation time        ls -lha time
10 000 files              3.94                    1.20
100 000 files            52.14                   11.48
1 000 000 files         572.70                  142.13

* With 10 properties (test 4)

                    file creation time        ls -lha time
10 000 files              4.61                    1.35
100 000 files            58.86                   13.83
1 000 000 files         656.01                  177.61

The increased latencies with properties are essencialy because of:

*) When creating an inode, we now synchronously write 1 more item
   (an xattr item) for each property inherited from the parent dir
   (or subvolume). This could be done in an asynchronous way such
   as we do for dir intex items (delayed-inode.c), which could help
   reduce the file creation latency;

*) With properties, we now have larger fs trees. For this particular
   test each xattr item uses 75 bytes of leaf space in the fs tree.
   This could be less by using a new item for xattr items, instead of
   the current btrfs_dir_item, since we could cut the 'location' and
   'type' fields (saving 18 bytes) and maybe 'transid' too (saving a
   total of 26 bytes per xattr item) from the btrfs_dir_item type.

Also tried batching the xattr insertions (ignoring proper hash
collision handling, since it didn't exist) when creating files that
inherit properties from their parent inode/subvolume, but the end
results were (surprisingly) essentially the same.

Test script:

$ cat test.pl
  #!/usr/bin/perl -w

  use strict;
  use Time::HiRes qw(time);
  use constant NUM_FILES =&gt; 10_000;
  use constant FILE_SIZES =&gt; (64 * 1024);
  use constant DEV =&gt; '/dev/sdb4';
  use constant MNT_POINT =&gt; '/home/fdmanana/btrfs-tests/dev';
  use constant TEST_DIR =&gt; (MNT_POINT . '/testdir');

  system("mkfs.btrfs", "-l", "16384", "-f", DEV) == 0 or die "mkfs.btrfs failed!";

  # following line for testing without properties
  #system("mount", "-o", "compress-force=lzo", DEV, MNT_POINT) == 0 or die "mount failed!";

  # following 2 lines for testing with properties
  system("mount", DEV, MNT_POINT) == 0 or die "mount failed!";
  system("btrfs", "prop", "set", MNT_POINT, "compression", "lzo") == 0 or die "set prop failed!";

  system("mkdir", TEST_DIR) == 0 or die "mkdir failed!";
  my ($t1, $t2);

  $t1 = time();
  for (my $i = 1; $i &lt;= NUM_FILES; $i++) {
      my $p = TEST_DIR . '/file_' . $i;
      open(my $f, '&gt;', $p) or die "Error opening file!";
      $f-&gt;autoflush(1);
      for (my $j = 0; $j &lt; FILE_SIZES; $j += 4096) {
          print $f ('A' x 4096) or die "Error writing to file!";
      }
      close($f);
  }
  $t2 = time();
  print "Time to create " . NUM_FILES . ": " . ($t2 - $t1) . " seconds.\n";
  system("umount", DEV) == 0 or die "umount failed!";
  system("mount", DEV, MNT_POINT) == 0 or die "mount failed!";

  $t1 = time();
  system("bash -c 'ls -lha " . TEST_DIR . " &gt; /dev/null'") == 0 or die "ls failed!";
  $t2 = time();
  print "Time to ls -lha all files: " . ($t2 - $t1) . " seconds.\n";
  system("umount", DEV) == 0 or die "umount failed!";

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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This change adds infrastructure to allow for generic properties for
inodes. Properties are name/value pairs that can be associated with
inodes for different purposes. They are stored as xattrs with the
prefix "btrfs."

Properties can be inherited - this means when a directory inode has
inheritable properties set, these are added to new inodes created
under that directory. Further, subvolumes can also have properties
associated with them, and they can be inherited from their parent
subvolume. Naturally, directory properties have priority over subvolume
properties (in practice a subvolume property is just a regular
property associated with the root inode, objectid 256, of the
subvolume's fs tree).

This change also adds one specific property implementation, named
"compression", whose values can be "lzo" or "zlib" and it's an
inheritable property.

The corresponding changes to btrfs-progs were also implemented.
A patch with xfstests for this feature will follow once there's
agreement on this change/feature.

Further, the script at the bottom of this commit message was used to
do some benchmarks to measure any performance penalties of this feature.

Basically the tests correspond to:

Test 1 - create a filesystem and mount it with compress-force=lzo,
then sequentially create N files of 64Kb each, measure how long it took
to create the files, unmount the filesystem, mount the filesystem and
perform an 'ls -lha' against the test directory holding the N files, and
report the time the command took.

Test 2 - create a filesystem and don't use any compression option when
mounting it - instead set the compression property of the subvolume's
root to 'lzo'. Then create N files of 64Kb, and report the time it took.
The unmount the filesystem, mount it again and perform an 'ls -lha' like
in the former test. This means every single file ends up with a property
(xattr) associated to it.

Test 3 - same as test 2, but uses 4 properties - 3 are duplicates of the
compression property, have no real effect other than adding more work
when inheriting properties and taking more btree leaf space.

Test 4 - same as test 3 but with 10 properties per file.

Results (in seconds, and averages of 5 runs each), for different N
numbers of files follow.

* Without properties (test 1)

                    file creation time        ls -lha time
10 000 files              3.49                   0.76
100 000 files            47.19                   8.37
1 000 000 files         518.51                 107.06

* With 1 property (compression property set to lzo - test 2)

                    file creation time        ls -lha time
10 000 files              3.63                    0.93
100 000 files            48.56                    9.74
1 000 000 files         537.72                  125.11

* With 4 properties (test 3)

                    file creation time        ls -lha time
10 000 files              3.94                    1.20
100 000 files            52.14                   11.48
1 000 000 files         572.70                  142.13

* With 10 properties (test 4)

                    file creation time        ls -lha time
10 000 files              4.61                    1.35
100 000 files            58.86                   13.83
1 000 000 files         656.01                  177.61

The increased latencies with properties are essencialy because of:

*) When creating an inode, we now synchronously write 1 more item
   (an xattr item) for each property inherited from the parent dir
   (or subvolume). This could be done in an asynchronous way such
   as we do for dir intex items (delayed-inode.c), which could help
   reduce the file creation latency;

*) With properties, we now have larger fs trees. For this particular
   test each xattr item uses 75 bytes of leaf space in the fs tree.
   This could be less by using a new item for xattr items, instead of
   the current btrfs_dir_item, since we could cut the 'location' and
   'type' fields (saving 18 bytes) and maybe 'transid' too (saving a
   total of 26 bytes per xattr item) from the btrfs_dir_item type.

Also tried batching the xattr insertions (ignoring proper hash
collision handling, since it didn't exist) when creating files that
inherit properties from their parent inode/subvolume, but the end
results were (surprisingly) essentially the same.

Test script:

$ cat test.pl
  #!/usr/bin/perl -w

  use strict;
  use Time::HiRes qw(time);
  use constant NUM_FILES =&gt; 10_000;
  use constant FILE_SIZES =&gt; (64 * 1024);
  use constant DEV =&gt; '/dev/sdb4';
  use constant MNT_POINT =&gt; '/home/fdmanana/btrfs-tests/dev';
  use constant TEST_DIR =&gt; (MNT_POINT . '/testdir');

  system("mkfs.btrfs", "-l", "16384", "-f", DEV) == 0 or die "mkfs.btrfs failed!";

  # following line for testing without properties
  #system("mount", "-o", "compress-force=lzo", DEV, MNT_POINT) == 0 or die "mount failed!";

  # following 2 lines for testing with properties
  system("mount", DEV, MNT_POINT) == 0 or die "mount failed!";
  system("btrfs", "prop", "set", MNT_POINT, "compression", "lzo") == 0 or die "set prop failed!";

  system("mkdir", TEST_DIR) == 0 or die "mkdir failed!";
  my ($t1, $t2);

  $t1 = time();
  for (my $i = 1; $i &lt;= NUM_FILES; $i++) {
      my $p = TEST_DIR . '/file_' . $i;
      open(my $f, '&gt;', $p) or die "Error opening file!";
      $f-&gt;autoflush(1);
      for (my $j = 0; $j &lt; FILE_SIZES; $j += 4096) {
          print $f ('A' x 4096) or die "Error writing to file!";
      }
      close($f);
  }
  $t2 = time();
  print "Time to create " . NUM_FILES . ": " . ($t2 - $t1) . " seconds.\n";
  system("umount", DEV) == 0 or die "umount failed!";
  system("mount", DEV, MNT_POINT) == 0 or die "mount failed!";

  $t1 = time();
  system("bash -c 'ls -lha " . TEST_DIR . " &gt; /dev/null'") == 0 or die "ls failed!";
  $t2 = time();
  print "Time to ls -lha all files: " . ($t2 - $t1) . " seconds.\n";
  system("umount", DEV) == 0 or die "umount failed!";

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;
</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: use generic posix ACL infrastructure</title>
<updated>2014-01-26T04:58:18+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@infradead.org</email>
</author>
<published>2013-12-20T13:16:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=996a710d46418cacb5b4a519ab9341a74066551d'/>
<id>996a710d46418cacb5b4a519ab9341a74066551d</id>
<content type='text'>
Also don't bother to set up a .get_acl method for symlinks as we do not
support access control (ACLs or even mode bits) for symlinks in Linux.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Also don't bother to set up a .get_acl method for symlinks as we do not
support access control (ACLs or even mode bits) for symlinks in Linux.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: make static code static &amp; remove dead code</title>
<updated>2013-05-06T19:55:23+00:00</updated>
<author>
<name>Eric Sandeen</name>
<email>sandeen@redhat.com</email>
</author>
<published>2013-04-25T20:41:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=48a3b6366f6913683563d934eb16fea67dead9c1'/>
<id>48a3b6366f6913683563d934eb16fea67dead9c1</id>
<content type='text'>
Big patch, but all it does is add statics to functions which
are in fact static, then remove the associated dead-code fallout.

removed functions:

btrfs_iref_to_path()
__btrfs_lookup_delayed_deletion_item()
__btrfs_search_delayed_insertion_item()
__btrfs_search_delayed_deletion_item()
find_eb_for_page()
btrfs_find_block_group()
range_straddles_pages()
extent_range_uptodate()
btrfs_file_extent_length()
btrfs_scrub_cancel_devid()
btrfs_start_transaction_lflush()

btrfs_print_tree() is left because it is used for debugging.
btrfs_start_transaction_lflush() and btrfs_reada_detach() are
left for symmetry.

ulist.c functions are left, another patch will take care of those.

Signed-off-by: Eric Sandeen &lt;sandeen@redhat.com&gt;
Signed-off-by: Josef Bacik &lt;jbacik@fusionio.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Big patch, but all it does is add statics to functions which
are in fact static, then remove the associated dead-code fallout.

removed functions:

btrfs_iref_to_path()
__btrfs_lookup_delayed_deletion_item()
__btrfs_search_delayed_insertion_item()
__btrfs_search_delayed_deletion_item()
find_eb_for_page()
btrfs_find_block_group()
range_straddles_pages()
extent_range_uptodate()
btrfs_file_extent_length()
btrfs_scrub_cancel_devid()
btrfs_start_transaction_lflush()

btrfs_print_tree() is left because it is used for debugging.
btrfs_start_transaction_lflush() and btrfs_reada_detach() are
left for symmetry.

ulist.c functions are left, another patch will take care of those.

Signed-off-by: Eric Sandeen &lt;sandeen@redhat.com&gt;
Signed-off-by: Josef Bacik &lt;jbacik@fusionio.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
