<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/aio.c, branch v3.1</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block</title>
<updated>2011-03-24T17:16:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2011-03-24T17:16:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6c5103890057b1bb781b26b7aae38d33e4c517d8'/>
<id>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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* '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}
</pre>
</div>
</content>
</entry>
<entry>
<title>aio: wake all waiters when destroying ctx</title>
<updated>2011-03-23T00:44:17+00:00</updated>
<author>
<name>Roland Dreier</name>
<email>roland@purestorage.com</email>
</author>
<published>2011-03-22T23:35:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e91f90bb0bb10be9cc8efd09a3cf4ecffcad0db1'/>
<id>e91f90bb0bb10be9cc8efd09a3cf4ecffcad0db1</id>
<content type='text'>
The test program below will hang because io_getevents() uses
add_wait_queue_exclusive(), which means the wake_up() in io_destroy() only
wakes up one of the threads.  Fix this by using wake_up_all() in the aio
code paths where we want to make sure no one gets stuck.

	// t.c -- compile with gcc -lpthread -laio t.c

	#include &lt;libaio.h&gt;
	#include &lt;pthread.h&gt;
	#include &lt;stdio.h&gt;
	#include &lt;unistd.h&gt;

	static const int nthr = 2;

	void *getev(void *ctx)
	{
		struct io_event ev;
		io_getevents(ctx, 1, 1, &amp;ev, NULL);
		printf("io_getevents returned\n");
		return NULL;
	}

	int main(int argc, char *argv[])
	{
		io_context_t ctx = 0;
		pthread_t thread[nthr];
		int i;

		io_setup(1024, &amp;ctx);

		for (i = 0; i &lt; nthr; ++i)
			pthread_create(&amp;thread[i], NULL, getev, ctx);

		sleep(1);

		io_destroy(ctx);

		for (i = 0; i &lt; nthr; ++i)
			pthread_join(thread[i], NULL);

		return 0;
	}

Signed-off-by: Roland Dreier &lt;roland@purestorage.com&gt;
Reviewed-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The test program below will hang because io_getevents() uses
add_wait_queue_exclusive(), which means the wake_up() in io_destroy() only
wakes up one of the threads.  Fix this by using wake_up_all() in the aio
code paths where we want to make sure no one gets stuck.

	// t.c -- compile with gcc -lpthread -laio t.c

	#include &lt;libaio.h&gt;
	#include &lt;pthread.h&gt;
	#include &lt;stdio.h&gt;
	#include &lt;unistd.h&gt;

	static const int nthr = 2;

	void *getev(void *ctx)
	{
		struct io_event ev;
		io_getevents(ctx, 1, 1, &amp;ev, NULL);
		printf("io_getevents returned\n");
		return NULL;
	}

	int main(int argc, char *argv[])
	{
		io_context_t ctx = 0;
		pthread_t thread[nthr];
		int i;

		io_setup(1024, &amp;ctx);

		for (i = 0; i &lt; nthr; ++i)
			pthread_create(&amp;thread[i], NULL, getev, ctx);

		sleep(1);

		io_destroy(ctx);

		for (i = 0; i &lt; nthr; ++i)
			pthread_join(thread[i], NULL);

		return 0;
	}

Signed-off-by: Roland Dreier &lt;roland@purestorage.com&gt;
Reviewed-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq</title>
<updated>2011-03-16T15:20:19+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2011-03-16T15:20:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bd2895eeade5f11f3e5906283c630bbdb4b57454'/>
<id>bd2895eeade5f11f3e5906283c630bbdb4b57454</id>
<content type='text'>
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix build failure introduced by s/freezeable/freezable/
  workqueue: add system_freezeable_wq
  rds/ib: use system_wq instead of rds_ib_fmr_wq
  net/9p: replace p9_poll_task with a work
  net/9p: use system_wq instead of p9_mux_wq
  xfs: convert to alloc_workqueue()
  reiserfs: make commit_wq use the default concurrency level
  ocfs2: use system_wq instead of ocfs2_quota_wq
  ext4: convert to alloc_workqueue()
  scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path
  scsi/be2iscsi,qla2xxx: convert to alloc_workqueue()
  misc/iwmc3200top: use system_wq instead of dedicated workqueues
  i2o: use alloc_workqueue() instead of create_workqueue()
  acpi: kacpi*_wq don't need WQ_MEM_RECLAIM
  fs/aio: aio_wq isn't used in memory reclaim path
  input/tps6507x-ts: use system_wq instead of dedicated workqueue
  cpufreq: use system_wq instead of dedicated workqueues
  wireless/ipw2x00: use system_wq instead of dedicated workqueues
  arm/omap: use system_wq in mailbox
  workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix build failure introduced by s/freezeable/freezable/
  workqueue: add system_freezeable_wq
  rds/ib: use system_wq instead of rds_ib_fmr_wq
  net/9p: replace p9_poll_task with a work
  net/9p: use system_wq instead of p9_mux_wq
  xfs: convert to alloc_workqueue()
  reiserfs: make commit_wq use the default concurrency level
  ocfs2: use system_wq instead of ocfs2_quota_wq
  ext4: convert to alloc_workqueue()
  scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path
  scsi/be2iscsi,qla2xxx: convert to alloc_workqueue()
  misc/iwmc3200top: use system_wq instead of dedicated workqueues
  i2o: use alloc_workqueue() instead of create_workqueue()
  acpi: kacpi*_wq don't need WQ_MEM_RECLAIM
  fs/aio: aio_wq isn't used in memory reclaim path
  input/tps6507x-ts: use system_wq instead of dedicated workqueue
  cpufreq: use system_wq instead of dedicated workqueues
  wireless/ipw2x00: use system_wq instead of dedicated workqueues
  arm/omap: use system_wq in mailbox
  workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/core</title>
<updated>2011-03-10T07:58:35+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>jaxboe@fusionio.com</email>
</author>
<published>2011-03-10T07:58:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4c63f5646e405b5010cc9499419060bf2e838f5b'/>
<id>4c63f5646e405b5010cc9499419060bf2e838f5b</id>
<content type='text'>
Conflicts:
	block/blk-core.c
	block/blk-flush.c
	drivers/md/raid1.c
	drivers/md/raid10.c
	drivers/md/raid5.c
	fs/nilfs2/btnode.c
	fs/nilfs2/mdt.c

Signed-off-by: Jens Axboe &lt;jaxboe@fusionio.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	block/blk-core.c
	block/blk-flush.c
	drivers/md/raid1.c
	drivers/md/raid10.c
	drivers/md/raid5.c
	fs/nilfs2/btnode.c
	fs/nilfs2/mdt.c

Signed-off-by: Jens Axboe &lt;jaxboe@fusionio.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>aio: remove request submission batching</title>
<updated>2011-03-10T07:52:27+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>jaxboe@fusionio.com</email>
</author>
<published>2011-03-03T01:12:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cf15900e1209d5b46ec2d24643adbf561830935f'/>
<id>cf15900e1209d5b46ec2d24643adbf561830935f</id>
<content type='text'>
This should be useless now that we have on-stack plugging. So lets just
kill it.

Signed-off-by: Jens Axboe &lt;jaxboe@fusionio.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This should be useless now that we have on-stack plugging. So lets just
kill it.

Signed-off-by: Jens Axboe &lt;jaxboe@fusionio.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs: make aio plug</title>
<updated>2011-03-10T07:52:27+00:00</updated>
<author>
<name>Shaohua Li</name>
<email>shaohua.li@intel.com</email>
</author>
<published>2010-07-01T05:55:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9f5b9425468c85a901d863d241ba5c5dff9b23b8'/>
<id>9f5b9425468c85a901d863d241ba5c5dff9b23b8</id>
<content type='text'>
Signed-off-by: Shaohua Li &lt;shaohua.li@intel.com&gt;
Signed-off-by: Jens Axboe &lt;jaxboe@fusionio.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Shaohua Li &lt;shaohua.li@intel.com&gt;
Signed-off-by: Jens Axboe &lt;jaxboe@fusionio.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: remove per-queue plugging</title>
<updated>2011-03-10T07:52:07+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>jaxboe@fusionio.com</email>
</author>
<published>2011-03-10T07:52:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7eaceaccab5f40bbfda044629a6298616aeaed50'/>
<id>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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>aio: fix race between io_destroy() and io_submit()</title>
<updated>2011-02-25T23:07:37+00:00</updated>
<author>
<name>Jan Kara</name>
<email>jack@suse.cz</email>
</author>
<published>2011-02-25T22:44:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7137c6bd455234bcb7560fd829e6ee49cae5fed6'/>
<id>7137c6bd455234bcb7560fd829e6ee49cae5fed6</id>
<content type='text'>
A race can occur when io_submit() races with io_destroy():

 CPU1						CPU2
io_submit()
  do_io_submit()
    ...
    ctx = lookup_ioctx(ctx_id);
						io_destroy()
    Now do_io_submit() holds the last reference to ctx.
    ...
    queue new AIO
    put_ioctx(ctx) - frees ctx with active AIOs

We solve this issue by checking whether ctx is being destroyed in AIO
submission path after adding new AIO to ctx.  Then we are guaranteed that
either io_destroy() waits for new AIO or we see that ctx is being
destroyed and bail out.

Cc: Nick Piggin &lt;npiggin@kernel.dk&gt;
Reviewed-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A race can occur when io_submit() races with io_destroy():

 CPU1						CPU2
io_submit()
  do_io_submit()
    ...
    ctx = lookup_ioctx(ctx_id);
						io_destroy()
    Now do_io_submit() holds the last reference to ctx.
    ...
    queue new AIO
    put_ioctx(ctx) - frees ctx with active AIOs

We solve this issue by checking whether ctx is being destroyed in AIO
submission path after adding new AIO to ctx.  Then we are guaranteed that
either io_destroy() waits for new AIO or we see that ctx is being
destroyed and bail out.

Cc: Nick Piggin &lt;npiggin@kernel.dk&gt;
Reviewed-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>aio: fix rcu ioctx lookup</title>
<updated>2011-02-25T23:07:37+00:00</updated>
<author>
<name>Nick Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2011-02-25T22:44:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3bd9a5d734c7cc7533b27abf451416c7f50095a7'/>
<id>3bd9a5d734c7cc7533b27abf451416c7f50095a7</id>
<content type='text'>
aio-dio-invalidate-failure GPFs in aio_put_req from io_submit.

lookup_ioctx doesn't implement the rcu lookup pattern properly.
rcu_read_lock does not prevent refcount going to zero, so we might take
a refcount on a zero count ioctx.

Fix the bug by atomically testing for zero refcount before incrementing.

[jack@suse.cz: added comment into the code]
Reviewed-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Signed-off-by: Nick Piggin &lt;npiggin@kernel.dk&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
aio-dio-invalidate-failure GPFs in aio_put_req from io_submit.

lookup_ioctx doesn't implement the rcu lookup pattern properly.
rcu_read_lock does not prevent refcount going to zero, so we might take
a refcount on a zero count ioctx.

Fix the bug by atomically testing for zero refcount before incrementing.

[jack@suse.cz: added comment into the code]
Reviewed-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Signed-off-by: Nick Piggin &lt;npiggin@kernel.dk&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs/aio: aio_wq isn't used in memory reclaim path</title>
<updated>2011-01-26T16:42:27+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2011-01-26T16:42:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d37adaa1596246929f7ab49843fd124595506175'/>
<id>d37adaa1596246929f7ab49843fd124595506175</id>
<content type='text'>
aio_wq isn't used during memory reclaim.  Convert to alloc_workqueue()
without WQ_MEM_RECLAIM.  It's possible to use system_wq but given that
the number of work items is determined from userland and the work item
may block, enforcing strict concurrency limit would be a good idea.

Also, move fput_work to system_wq so that aio_wq is used soley to
throttle the max concurrency of aio work items and fput_work doesn't
interact with other work items.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Acked-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Cc: Benjamin LaHaise &lt;bcrl@kvack.org&gt;
Cc: linux-aio@kvack.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
aio_wq isn't used during memory reclaim.  Convert to alloc_workqueue()
without WQ_MEM_RECLAIM.  It's possible to use system_wq but given that
the number of work items is determined from userland and the work item
may block, enforcing strict concurrency limit would be a good idea.

Also, move fput_work to system_wq so that aio_wq is used soley to
throttle the max concurrency of aio work items and fput_work doesn't
interact with other work items.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Acked-by: Jeff Moyer &lt;jmoyer@redhat.com&gt;
Cc: Benjamin LaHaise &lt;bcrl@kvack.org&gt;
Cc: linux-aio@kvack.org
</pre>
</div>
</content>
</entry>
</feed>
