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<title>linux/fs/hpfs, branch v2.6.39-rc2</title>
<subtitle>Linux Kernel (branches are rebased on master from time to time)</subtitle>
<id>https://sre.ring0.de/linux/atom?h=v2.6.39-rc2</id>
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<updated>2011-03-24T17:16:26Z</updated>
<entry>
<title>Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block</title>
<updated>2011-03-24T17:16:26Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2011-03-24T17:16:26Z</published>
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<id>urn:sha1:6c5103890057b1bb781b26b7aae38d33e4c517d8</id>
<content type='text'>
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb-&gt;s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq-&gt;cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}
</content>
</entry>
<entry>
<title>block: remove per-queue plugging</title>
<updated>2011-03-10T07:52:07Z</updated>
<author>
<name>Jens Axboe</name>
<email>jaxboe@fusionio.com</email>
</author>
<published>2011-03-10T07:52:07Z</published>
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<id>urn:sha1:7eaceaccab5f40bbfda044629a6298616aeaed50</id>
<content type='text'>
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops-&gt;sync_page().

Signed-off-by: Jens Axboe &lt;jaxboe@fusionio.com&gt;
</content>
</entry>
<entry>
<title>hpfs: remove the BKL</title>
<updated>2011-03-02T21:27:36Z</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2011-01-22T19:26:12Z</published>
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<id>urn:sha1:9a311b96c3065f362e3348cb5d7af1a57ca6bff9</id>
<content type='text'>
This removes the BKL in hpfs in a rather awful
way, by making the code only work on uniprocessor
systems without kernel preemption, as suggested
by Andi Kleen.

The HPFS code probably has close to zero remaining
users on current kernels, all archeological uses of
the file system can probably be done with the significant
restrictions.

The hpfs_lock/hpfs_unlock functions are left in the
code, sincen Mikulas has indicated that he is still
interested in fixing it in a better way.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Mikulas Patocka &lt;mikulas@artax.karlin.mff.cuni.cz&gt;
Cc: linux-fsdevel@vger.kernel.org
</content>
</entry>
<entry>
<title>hpfs_setattr error case avoids unlock_kernel</title>
<updated>2011-01-17T10:11:37Z</updated>
<author>
<name>Dr. David Alan Gilbert</name>
<email>linux@treblig.org</email>
</author>
<published>2010-12-13T17:09:52Z</published>
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<id>urn:sha1:274052ef0bac011249925f6616d147b1491fc601</id>
<content type='text'>
This fixed a case that 'sparse' spotted where hpfs_setattr has an error return
that didn't go through it's path that unlocks.

This is against git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
version 6313e3c21743cc88bb5bd8aa72948ee1e83937b6.

Build tested only, I don't have an hpfs file system to test.

Dave

Signed-off-by: Dr. David Alan Gilbert &lt;linux@treblig.org&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
</entry>
<entry>
<title>switch hpfs</title>
<updated>2011-01-13T01:02:47Z</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2011-01-12T21:12:05Z</published>
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<id>urn:sha1:43d344d7722f9b914849ba0014342111a9a0b03e</id>
<content type='text'>
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
</entry>
<entry>
<title>fs: provide rcu-walk aware permission i_ops</title>
<updated>2011-01-07T06:50:29Z</updated>
<author>
<name>Nick Piggin</name>
<email>npiggin@kernel.dk</email>
</author>
<published>2011-01-07T06:49:58Z</published>
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<id>urn:sha1:b74c79e99389cd79b31fcc08f82c24e492e63c7e</id>
<content type='text'>
Signed-off-by: Nick Piggin &lt;npiggin@kernel.dk&gt;
</content>
</entry>
<entry>
<title>fs: dcache reduce branches in lookup path</title>
<updated>2011-01-07T06:50:28Z</updated>
<author>
<name>Nick Piggin</name>
<email>npiggin@kernel.dk</email>
</author>
<published>2011-01-07T06:49:55Z</published>
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<id>urn:sha1:fb045adb99d9b7c562dc7fef834857f78249daa1</id>
<content type='text'>
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry-&gt;d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.&gt;]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)-&gt;d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&amp;\1, \2);/' -i

Signed-off-by: Nick Piggin &lt;npiggin@kernel.dk&gt;
</content>
</entry>
<entry>
<title>fs: icache RCU free inodes</title>
<updated>2011-01-07T06:50:26Z</updated>
<author>
<name>Nick Piggin</name>
<email>npiggin@kernel.dk</email>
</author>
<published>2011-01-07T06:49:49Z</published>
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<id>urn:sha1:fa0d7e3de6d6fc5004ad9dea0dd6b286af8f03e9</id>
<content type='text'>
RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page-&gt;mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin &lt;npiggin@kernel.dk&gt;
</content>
</entry>
<entry>
<title>fs: change d_hash for rcu-walk</title>
<updated>2011-01-07T06:50:20Z</updated>
<author>
<name>Nick Piggin</name>
<email>npiggin@kernel.dk</email>
</author>
<published>2011-01-07T06:49:28Z</published>
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<id>urn:sha1:b1e6a015a580ad145689ad1d6b4aa0e03e6c868b</id>
<content type='text'>
Change d_hash so it may be called from lock-free RCU lookups. See similar
patch for d_compare for details.

For in-tree filesystems, this is just a mechanical change.

Signed-off-by: Nick Piggin &lt;npiggin@kernel.dk&gt;
</content>
</entry>
<entry>
<title>fs: change d_compare for rcu-walk</title>
<updated>2011-01-07T06:50:19Z</updated>
<author>
<name>Nick Piggin</name>
<email>npiggin@kernel.dk</email>
</author>
<published>2011-01-07T06:49:27Z</published>
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<id>urn:sha1:621e155a3591962420eacdd39f6f0aa29ceb221e</id>
<content type='text'>
Change d_compare so it may be called from lock-free RCU lookups. This
does put significant restrictions on what may be done from the callback,
however there don't seem to have been any problems with in-tree fses.
If some strange use case pops up that _really_ cannot cope with the
rcu-walk rules, we can just add new rcu-unaware callbacks, which would
cause name lookup to drop out of rcu-walk mode.

For in-tree filesystems, this is just a mechanical change.

Signed-off-by: Nick Piggin &lt;npiggin@kernel.dk&gt;
</content>
</entry>
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