* Re: [Bug 12945] New: SCSI Generic (sg): BUG: sleeping function called from invalid context
2009-03-26 14:49 ` [Bug 12945] New: " Andrew Morton
@ 2009-03-26 18:43 ` Jens Axboe
2009-03-27 4:09 ` FUJITA Tomonori
2009-03-26 18:45 ` Tobias X
2009-03-27 3:51 ` FUJITA Tomonori
2 siblings, 1 reply; 13+ messages in thread
From: Jens Axboe @ 2009-03-26 18:43 UTC (permalink / raw)
To: Andrew Morton
Cc: bugzilla-daemon, linux-scsi, txtoxtox285, FUJITA Tomonori,
Douglas Gilbert, James Bottomley
On Thu, Mar 26 2009, Andrew Morton wrote:
>
> (switched to email. Please respond via emailed reply-to-all, not via the
> bugzilla web interface).
>
> On Thu, 26 Mar 2009 12:27:53 GMT bugzilla-daemon@bugzilla.kernel.org wrote:
>
> > http://bugzilla.kernel.org/show_bug.cgi?id=12945
> >
> > Summary: SCSI Generic (sg): BUG: sleeping function called from
> > invalid context
> > Product: SCSI Drivers
> > Version: 2.5
> > Kernel Version: 2.6.28.9
> > Platform: All
> > OS/Version: Linux
> > Tree: Mainline
> > Status: NEW
> > Severity: normal
> > Priority: P1
> > Component: Other
> > AssignedTo: scsi_drivers-other@kernel-bugs.osdl.org
> > ReportedBy: txtoxtox285@googlemail.com
> > Regression: No
> >
> >
> > Created an attachment (id=20685)
> > --> (http://bugzilla.kernel.org/attachment.cgi?id=20685)
> > Stack trace on program kill (2.6.28.9)
> >
> > I am experimenting with CD audio extraction. I use the SCSI Generic driver for
> > this.
> >
> > My test program uses read() and write() (instead of ioctl) to send requests to
> > the driver and receive responses. I use SG_FLAG_DIRECT_IO.
> >
> > When I kill my program (because I don't want to wait until it has ripped the
> > entire CD), I am often rewarded with messages like "BUG: sleeping function
> > called from invalid context at linux-2.6.28.9/include/linux/pagemap.h:347". I
> > have attached typical stack trace.
> >
> > Another case when I hit this BUG is when I set a time out and the CD drive
> > doesn't respond fast enough. A stack trace is attached.
>
> > [34215.786870] BUG: sleeping function called from invalid context at /mnt/var-pub/src/linux-2.6.28.9/include/linux/pagemap.h:347
> > [34215.786880] in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper
> > [34215.786886] Pid: 0, comm: swapper Not tainted 2.6.28.9 #1
> > [34215.786890] Call Trace:
> > [34215.786894] <IRQ> [<ffffffff8026c4cc>] set_page_dirty_lock+0x1a/0x45
> > [34215.786911] [<ffffffff802ae17d>] bio_unmap_user+0x1e/0x4a
> > [34215.786920] [<ffffffff802e876b>] __blk_rq_unmap_user+0x14/0x20
> > [34215.786928] [<ffffffff80210852>] pit_next_event+0x2e/0x49
> > [34215.786934] [<ffffffff802e8795>] blk_rq_unmap_user+0x1e/0x4b
> > [34215.786965] [<ffffffffa0163475>] sg_finish_rem_req+0x6d/0x88 [sg]
> > [34215.786979] [<ffffffffa0164ef3>] sg_rq_end_io+0x131/0x205 [sg]
> > [34215.786986] [<ffffffff802e5c1f>] end_that_request_last+0x58/0x194
> > [34215.786992] [<ffffffff802e5e00>] blk_end_io+0x48/0x7d
> > [34215.787019] [<ffffffffa0026bef>] scsi_next_command+0x219/0x283 [scsi_mod]
> > [34215.787039] [<ffffffffa00279b1>] scsi_io_completion+0x181/0x53b [scsi_mod]
> > [34215.787047] [<ffffffff802e9737>] blk_done_softirq+0x5f/0x6d
> > [34215.787054] [<ffffffff80230787>] __do_softirq+0x5e/0xf8
> > [34215.787061] [<ffffffff8020ca8c>] call_softirq+0x1c/0x28
> > [34215.787067] [<ffffffff8020d6bc>] do_softirq+0x2c/0x68
> > [34215.787073] [<ffffffff80230696>] irq_exit+0x36/0x82
> > [34215.787079] [<ffffffff8020d79e>] do_IRQ+0xa6/0xb8
> > [34215.787085] [<ffffffff8020c256>] ret_from_intr+0x0/0xa
> > [34215.787088] <EOI> [<ffffffff8034f648>] menu_reflect+0x0/0x6d
> > [34215.787112] [<ffffffffa0147d51>] acpi_idle_enter_simple+0x170/0x1d6 [processor]
> > [34215.787127] [<ffffffffa0147d47>] acpi_idle_enter_simple+0x166/0x1d6 [processor]
> > [34215.787134] [<ffffffff8034eb32>] cpuidle_idle_call+0x73/0xb1
> > [34215.787140] [<ffffffff8020ac2a>] cpu_idle+0x3c/0x73
>
> Argh. sg_finish_rem_req() is called from interrupt context. But
> blk_rq_unmap_user() can run
> __bio_unmap_user()->set_page_dirty_lock()->lock_page(), which can call
> schedule(). If it does call schedule(), the machine will crash.
>
> afacit, blk_rq_unmap_user() has always been a can-sleep function, and
> this is a regression caused by
>
> commit 6e5a30cba5e7c03b2cd564e968f1dd667a0f7c42
Yep, it is. The problem is the usage of:
blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
srp->rq, 1, sg_rq_end_io);
and then doing the sg_finish_rem_req() -> blk_rq_unmap_user() from the
end_io path, where other users do a sync request and then unmap from the
same context. Hmm. Perhaps we can add some request flag to specify doing
the completion from user context, then other users could be converted do
the _nowait() approach as well and get some unification/cleanup there as
well.
I'll cook up a patch.
--
Jens Axboe
^ permalink raw reply [flat|nested] 13+ messages in thread* Re: [Bug 12945] New: SCSI Generic (sg): BUG: sleeping function called from invalid context
2009-03-26 18:43 ` Jens Axboe
@ 2009-03-27 4:09 ` FUJITA Tomonori
2009-03-27 6:57 ` Jens Axboe
0 siblings, 1 reply; 13+ messages in thread
From: FUJITA Tomonori @ 2009-03-27 4:09 UTC (permalink / raw)
To: jens.axboe
Cc: akpm, bugzilla-daemon, linux-scsi, txtoxtox285, fujita.tomonori,
dougg, James.Bottomley
On Thu, 26 Mar 2009 19:43:02 +0100
Jens Axboe <jens.axboe@oracle.com> wrote:
> On Thu, Mar 26 2009, Andrew Morton wrote:
> >
> > (switched to email. Please respond via emailed reply-to-all, not via the
> > bugzilla web interface).
> >
> > On Thu, 26 Mar 2009 12:27:53 GMT bugzilla-daemon@bugzilla.kernel.org wrote:
> >
> > > http://bugzilla.kernel.org/show_bug.cgi?id=12945
> > >
> > > Summary: SCSI Generic (sg): BUG: sleeping function called from
> > > invalid context
> > > Product: SCSI Drivers
> > > Version: 2.5
> > > Kernel Version: 2.6.28.9
> > > Platform: All
> > > OS/Version: Linux
> > > Tree: Mainline
> > > Status: NEW
> > > Severity: normal
> > > Priority: P1
> > > Component: Other
> > > AssignedTo: scsi_drivers-other@kernel-bugs.osdl.org
> > > ReportedBy: txtoxtox285@googlemail.com
> > > Regression: No
> > >
> > >
> > > Created an attachment (id=20685)
> > > --> (http://bugzilla.kernel.org/attachment.cgi?id=20685)
> > > Stack trace on program kill (2.6.28.9)
> > >
> > > I am experimenting with CD audio extraction. I use the SCSI Generic driver for
> > > this.
> > >
> > > My test program uses read() and write() (instead of ioctl) to send requests to
> > > the driver and receive responses. I use SG_FLAG_DIRECT_IO.
> > >
> > > When I kill my program (because I don't want to wait until it has ripped the
> > > entire CD), I am often rewarded with messages like "BUG: sleeping function
> > > called from invalid context at linux-2.6.28.9/include/linux/pagemap.h:347". I
> > > have attached typical stack trace.
> > >
> > > Another case when I hit this BUG is when I set a time out and the CD drive
> > > doesn't respond fast enough. A stack trace is attached.
> >
> > > [34215.786870] BUG: sleeping function called from invalid context at /mnt/var-pub/src/linux-2.6.28.9/include/linux/pagemap.h:347
> > > [34215.786880] in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper
> > > [34215.786886] Pid: 0, comm: swapper Not tainted 2.6.28.9 #1
> > > [34215.786890] Call Trace:
> > > [34215.786894] <IRQ> [<ffffffff8026c4cc>] set_page_dirty_lock+0x1a/0x45
> > > [34215.786911] [<ffffffff802ae17d>] bio_unmap_user+0x1e/0x4a
> > > [34215.786920] [<ffffffff802e876b>] __blk_rq_unmap_user+0x14/0x20
> > > [34215.786928] [<ffffffff80210852>] pit_next_event+0x2e/0x49
> > > [34215.786934] [<ffffffff802e8795>] blk_rq_unmap_user+0x1e/0x4b
> > > [34215.786965] [<ffffffffa0163475>] sg_finish_rem_req+0x6d/0x88 [sg]
> > > [34215.786979] [<ffffffffa0164ef3>] sg_rq_end_io+0x131/0x205 [sg]
> > > [34215.786986] [<ffffffff802e5c1f>] end_that_request_last+0x58/0x194
> > > [34215.786992] [<ffffffff802e5e00>] blk_end_io+0x48/0x7d
> > > [34215.787019] [<ffffffffa0026bef>] scsi_next_command+0x219/0x283 [scsi_mod]
> > > [34215.787039] [<ffffffffa00279b1>] scsi_io_completion+0x181/0x53b [scsi_mod]
> > > [34215.787047] [<ffffffff802e9737>] blk_done_softirq+0x5f/0x6d
> > > [34215.787054] [<ffffffff80230787>] __do_softirq+0x5e/0xf8
> > > [34215.787061] [<ffffffff8020ca8c>] call_softirq+0x1c/0x28
> > > [34215.787067] [<ffffffff8020d6bc>] do_softirq+0x2c/0x68
> > > [34215.787073] [<ffffffff80230696>] irq_exit+0x36/0x82
> > > [34215.787079] [<ffffffff8020d79e>] do_IRQ+0xa6/0xb8
> > > [34215.787085] [<ffffffff8020c256>] ret_from_intr+0x0/0xa
> > > [34215.787088] <EOI> [<ffffffff8034f648>] menu_reflect+0x0/0x6d
> > > [34215.787112] [<ffffffffa0147d51>] acpi_idle_enter_simple+0x170/0x1d6 [processor]
> > > [34215.787127] [<ffffffffa0147d47>] acpi_idle_enter_simple+0x166/0x1d6 [processor]
> > > [34215.787134] [<ffffffff8034eb32>] cpuidle_idle_call+0x73/0xb1
> > > [34215.787140] [<ffffffff8020ac2a>] cpu_idle+0x3c/0x73
> >
> > Argh. sg_finish_rem_req() is called from interrupt context. But
> > blk_rq_unmap_user() can run
> > __bio_unmap_user()->set_page_dirty_lock()->lock_page(), which can call
> > schedule(). If it does call schedule(), the machine will crash.
> >
> > afacit, blk_rq_unmap_user() has always been a can-sleep function, and
> > this is a regression caused by
> >
> > commit 6e5a30cba5e7c03b2cd564e968f1dd667a0f7c42
>
> Yep, it is. The problem is the usage of:
>
> blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
> srp->rq, 1, sg_rq_end_io);
>
> and then doing the sg_finish_rem_req() -> blk_rq_unmap_user() from the
> end_io path, where other users do a sync request and then unmap from the
> same context.
Right. And only sg does that. I've already converted st and osst to
use the block layer but they works synchronously.
> Hmm. Perhaps we can add some request flag to specify doing
> the completion from user context, then other users could be converted do
> the _nowait() approach as well and get some unification/cleanup there as
> well.
Since only sg needs this so I simply fixed sg instead of changing the
block layer. But it might be nice if block layer can handle this.
Seems there are several patches for the block layer (including
mapping) from Tejun and Boaz. I'll read them to see what we could do.
I'm always too busy in March with the company matters.
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [Bug 12945] New: SCSI Generic (sg): BUG: sleeping function called from invalid context
2009-03-27 4:09 ` FUJITA Tomonori
@ 2009-03-27 6:57 ` Jens Axboe
0 siblings, 0 replies; 13+ messages in thread
From: Jens Axboe @ 2009-03-27 6:57 UTC (permalink / raw)
To: FUJITA Tomonori
Cc: akpm, bugzilla-daemon, linux-scsi, txtoxtox285, dougg,
James.Bottomley
On Fri, Mar 27 2009, FUJITA Tomonori wrote:
> On Thu, 26 Mar 2009 19:43:02 +0100
> Jens Axboe <jens.axboe@oracle.com> wrote:
>
> > On Thu, Mar 26 2009, Andrew Morton wrote:
> > >
> > > (switched to email. Please respond via emailed reply-to-all, not via the
> > > bugzilla web interface).
> > >
> > > On Thu, 26 Mar 2009 12:27:53 GMT bugzilla-daemon@bugzilla.kernel.org wrote:
> > >
> > > > http://bugzilla.kernel.org/show_bug.cgi?id=12945
> > > >
> > > > Summary: SCSI Generic (sg): BUG: sleeping function called from
> > > > invalid context
> > > > Product: SCSI Drivers
> > > > Version: 2.5
> > > > Kernel Version: 2.6.28.9
> > > > Platform: All
> > > > OS/Version: Linux
> > > > Tree: Mainline
> > > > Status: NEW
> > > > Severity: normal
> > > > Priority: P1
> > > > Component: Other
> > > > AssignedTo: scsi_drivers-other@kernel-bugs.osdl.org
> > > > ReportedBy: txtoxtox285@googlemail.com
> > > > Regression: No
> > > >
> > > >
> > > > Created an attachment (id=20685)
> > > > --> (http://bugzilla.kernel.org/attachment.cgi?id=20685)
> > > > Stack trace on program kill (2.6.28.9)
> > > >
> > > > I am experimenting with CD audio extraction. I use the SCSI Generic driver for
> > > > this.
> > > >
> > > > My test program uses read() and write() (instead of ioctl) to send requests to
> > > > the driver and receive responses. I use SG_FLAG_DIRECT_IO.
> > > >
> > > > When I kill my program (because I don't want to wait until it has ripped the
> > > > entire CD), I am often rewarded with messages like "BUG: sleeping function
> > > > called from invalid context at linux-2.6.28.9/include/linux/pagemap.h:347". I
> > > > have attached typical stack trace.
> > > >
> > > > Another case when I hit this BUG is when I set a time out and the CD drive
> > > > doesn't respond fast enough. A stack trace is attached.
> > >
> > > > [34215.786870] BUG: sleeping function called from invalid context at /mnt/var-pub/src/linux-2.6.28.9/include/linux/pagemap.h:347
> > > > [34215.786880] in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper
> > > > [34215.786886] Pid: 0, comm: swapper Not tainted 2.6.28.9 #1
> > > > [34215.786890] Call Trace:
> > > > [34215.786894] <IRQ> [<ffffffff8026c4cc>] set_page_dirty_lock+0x1a/0x45
> > > > [34215.786911] [<ffffffff802ae17d>] bio_unmap_user+0x1e/0x4a
> > > > [34215.786920] [<ffffffff802e876b>] __blk_rq_unmap_user+0x14/0x20
> > > > [34215.786928] [<ffffffff80210852>] pit_next_event+0x2e/0x49
> > > > [34215.786934] [<ffffffff802e8795>] blk_rq_unmap_user+0x1e/0x4b
> > > > [34215.786965] [<ffffffffa0163475>] sg_finish_rem_req+0x6d/0x88 [sg]
> > > > [34215.786979] [<ffffffffa0164ef3>] sg_rq_end_io+0x131/0x205 [sg]
> > > > [34215.786986] [<ffffffff802e5c1f>] end_that_request_last+0x58/0x194
> > > > [34215.786992] [<ffffffff802e5e00>] blk_end_io+0x48/0x7d
> > > > [34215.787019] [<ffffffffa0026bef>] scsi_next_command+0x219/0x283 [scsi_mod]
> > > > [34215.787039] [<ffffffffa00279b1>] scsi_io_completion+0x181/0x53b [scsi_mod]
> > > > [34215.787047] [<ffffffff802e9737>] blk_done_softirq+0x5f/0x6d
> > > > [34215.787054] [<ffffffff80230787>] __do_softirq+0x5e/0xf8
> > > > [34215.787061] [<ffffffff8020ca8c>] call_softirq+0x1c/0x28
> > > > [34215.787067] [<ffffffff8020d6bc>] do_softirq+0x2c/0x68
> > > > [34215.787073] [<ffffffff80230696>] irq_exit+0x36/0x82
> > > > [34215.787079] [<ffffffff8020d79e>] do_IRQ+0xa6/0xb8
> > > > [34215.787085] [<ffffffff8020c256>] ret_from_intr+0x0/0xa
> > > > [34215.787088] <EOI> [<ffffffff8034f648>] menu_reflect+0x0/0x6d
> > > > [34215.787112] [<ffffffffa0147d51>] acpi_idle_enter_simple+0x170/0x1d6 [processor]
> > > > [34215.787127] [<ffffffffa0147d47>] acpi_idle_enter_simple+0x166/0x1d6 [processor]
> > > > [34215.787134] [<ffffffff8034eb32>] cpuidle_idle_call+0x73/0xb1
> > > > [34215.787140] [<ffffffff8020ac2a>] cpu_idle+0x3c/0x73
> > >
> > > Argh. sg_finish_rem_req() is called from interrupt context. But
> > > blk_rq_unmap_user() can run
> > > __bio_unmap_user()->set_page_dirty_lock()->lock_page(), which can call
> > > schedule(). If it does call schedule(), the machine will crash.
> > >
> > > afacit, blk_rq_unmap_user() has always been a can-sleep function, and
> > > this is a regression caused by
> > >
> > > commit 6e5a30cba5e7c03b2cd564e968f1dd667a0f7c42
> >
> > Yep, it is. The problem is the usage of:
> >
> > blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
> > srp->rq, 1, sg_rq_end_io);
> >
> > and then doing the sg_finish_rem_req() -> blk_rq_unmap_user() from the
> > end_io path, where other users do a sync request and then unmap from the
> > same context.
>
> Right. And only sg does that. I've already converted st and osst to
> use the block layer but they works synchronously.
Precisely.
>
> > Hmm. Perhaps we can add some request flag to specify doing
> > the completion from user context, then other users could be converted do
> > the _nowait() approach as well and get some unification/cleanup there as
> > well.
>
> Since only sg needs this so I simply fixed sg instead of changing the
> block layer. But it might be nice if block layer can handle this.
>
> Seems there are several patches for the block layer (including
> mapping) from Tejun and Boaz. I'll read them to see what we could do.
> I'm always too busy in March with the company matters.
OK, let me know what you find in the scsi tree. I'll hold off on this
one.
--
Jens Axboe
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [Bug 12945] New: SCSI Generic (sg): BUG: sleeping function called from invalid context
2009-03-26 14:49 ` [Bug 12945] New: " Andrew Morton
2009-03-26 18:43 ` Jens Axboe
@ 2009-03-26 18:45 ` Tobias X
2009-03-27 3:51 ` FUJITA Tomonori
2 siblings, 0 replies; 13+ messages in thread
From: Tobias X @ 2009-03-26 18:45 UTC (permalink / raw)
To: Andrew Morton
Cc: bugzilla-daemon, linux-scsi, FUJITA Tomonori, Jens Axboe,
Douglas Gilbert, James Bottomley
On Thu, Mar 26, 2009 at 3:49 PM, Andrew Morton
<akpm@linux-foundation.org> wrote:
>
> (switched to email. Please respond via emailed reply-to-all, not via the
> bugzilla web interface).
>
> On Thu, 26 Mar 2009 12:27:53 GMT bugzilla-daemon@bugzilla.kernel.org wrote:
>
>> http://bugzilla.kernel.org/show_bug.cgi?id=12945
>>
>> Summary: SCSI Generic (sg): BUG: sleeping function called from
>> invalid context
>> Product: SCSI Drivers
>> Version: 2.5
>> Kernel Version: 2.6.28.9
>> Platform: All
>> OS/Version: Linux
>> Tree: Mainline
>> Status: NEW
>> Severity: normal
>> Priority: P1
>> Component: Other
>> AssignedTo: scsi_drivers-other@kernel-bugs.osdl.org
>> ReportedBy: txtoxtox285@googlemail.com
>> Regression: No
>>
>>
>> Created an attachment (id=20685)
>> --> (http://bugzilla.kernel.org/attachment.cgi?id=20685)
>> Stack trace on program kill (2.6.28.9)
>>
>> I am experimenting with CD audio extraction. I use the SCSI Generic driver for
>> this.
>>
>> My test program uses read() and write() (instead of ioctl) to send requests to
>> the driver and receive responses. I use SG_FLAG_DIRECT_IO.
>>
>> When I kill my program (because I don't want to wait until it has ripped the
>> entire CD), I am often rewarded with messages like "BUG: sleeping function
>> called from invalid context at linux-2.6.28.9/include/linux/pagemap.h:347". I
>> have attached typical stack trace.
>>
>> Another case when I hit this BUG is when I set a time out and the CD drive
>> doesn't respond fast enough. A stack trace is attached.
>
>> [34215.786870] BUG: sleeping function called from invalid context at /mnt/var-pub/src/linux-2.6.28.9/include/linux/pagemap.h:347
>> [34215.786880] in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper
>> [34215.786886] Pid: 0, comm: swapper Not tainted 2.6.28.9 #1
>> [34215.786890] Call Trace:
>> [34215.786894] <IRQ> [<ffffffff8026c4cc>] set_page_dirty_lock+0x1a/0x45
>> [34215.786911] [<ffffffff802ae17d>] bio_unmap_user+0x1e/0x4a
>> [34215.786920] [<ffffffff802e876b>] __blk_rq_unmap_user+0x14/0x20
>> [34215.786928] [<ffffffff80210852>] pit_next_event+0x2e/0x49
>> [34215.786934] [<ffffffff802e8795>] blk_rq_unmap_user+0x1e/0x4b
>> [34215.786965] [<ffffffffa0163475>] sg_finish_rem_req+0x6d/0x88 [sg]
>> [34215.786979] [<ffffffffa0164ef3>] sg_rq_end_io+0x131/0x205 [sg]
>> [34215.786986] [<ffffffff802e5c1f>] end_that_request_last+0x58/0x194
>> [34215.786992] [<ffffffff802e5e00>] blk_end_io+0x48/0x7d
>> [34215.787019] [<ffffffffa0026bef>] scsi_next_command+0x219/0x283 [scsi_mod]
>> [34215.787039] [<ffffffffa00279b1>] scsi_io_completion+0x181/0x53b [scsi_mod]
>> [34215.787047] [<ffffffff802e9737>] blk_done_softirq+0x5f/0x6d
>> [34215.787054] [<ffffffff80230787>] __do_softirq+0x5e/0xf8
>> [34215.787061] [<ffffffff8020ca8c>] call_softirq+0x1c/0x28
>> [34215.787067] [<ffffffff8020d6bc>] do_softirq+0x2c/0x68
>> [34215.787073] [<ffffffff80230696>] irq_exit+0x36/0x82
>> [34215.787079] [<ffffffff8020d79e>] do_IRQ+0xa6/0xb8
>> [34215.787085] [<ffffffff8020c256>] ret_from_intr+0x0/0xa
>> [34215.787088] <EOI> [<ffffffff8034f648>] menu_reflect+0x0/0x6d
>> [34215.787112] [<ffffffffa0147d51>] acpi_idle_enter_simple+0x170/0x1d6 [processor]
>> [34215.787127] [<ffffffffa0147d47>] acpi_idle_enter_simple+0x166/0x1d6 [processor]
>> [34215.787134] [<ffffffff8034eb32>] cpuidle_idle_call+0x73/0xb1
>> [34215.787140] [<ffffffff8020ac2a>] cpu_idle+0x3c/0x73
>
> Argh. sg_finish_rem_req() is called from interrupt context. But
> blk_rq_unmap_user() can run
> __bio_unmap_user()->set_page_dirty_lock()->lock_page(), which can call
> schedule(). If it does call schedule(), the machine will crash.
>
> afacit, blk_rq_unmap_user() has always been a can-sleep function, and
> this is a regression caused by
>
> commit 6e5a30cba5e7c03b2cd564e968f1dd667a0f7c42
> Author: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> AuthorDate: Thu Aug 28 16:17:08 2008 +0900
> Commit: Jens Axboe <jens.axboe@oracle.com>
> CommitDate: Thu Oct 9 08:56:10 2008 +0200
>
> sg: convert the direct IO path to use the block layer
>
> This patch converts the direct IO path (SG_FLAG_DIRECT_IO) to use the
> block layer functions (blk_get_request, blk_execute_rq_nowait,
> blk_rq_map_user, etc) instead of scsi_execute_async().
>
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> Signed-off-by: Douglas Gilbert <dougg@torque.net>
> Cc: Mike Christie <michaelc@cs.wisc.edu>
> Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
>
>
Andrew,
thank you for your quick response. So as a temporary workaround I will
not use direct I/O and wait for a patch.
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [Bug 12945] New: SCSI Generic (sg): BUG: sleeping function called from invalid context
2009-03-26 14:49 ` [Bug 12945] New: " Andrew Morton
2009-03-26 18:43 ` Jens Axboe
2009-03-26 18:45 ` Tobias X
@ 2009-03-27 3:51 ` FUJITA Tomonori
2 siblings, 0 replies; 13+ messages in thread
From: FUJITA Tomonori @ 2009-03-27 3:51 UTC (permalink / raw)
To: akpm
Cc: bugzilla-daemon, linux-scsi, txtoxtox285, fujita.tomonori,
jens.axboe, dougg, James.Bottomley
On Thu, 26 Mar 2009 07:49:52 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:
>
> (switched to email. Please respond via emailed reply-to-all, not via the
> bugzilla web interface).
>
> On Thu, 26 Mar 2009 12:27:53 GMT bugzilla-daemon@bugzilla.kernel.org wrote:
>
> > http://bugzilla.kernel.org/show_bug.cgi?id=12945
> >
> > Summary: SCSI Generic (sg): BUG: sleeping function called from
> > invalid context
> > Product: SCSI Drivers
> > Version: 2.5
> > Kernel Version: 2.6.28.9
> > Platform: All
> > OS/Version: Linux
> > Tree: Mainline
> > Status: NEW
> > Severity: normal
> > Priority: P1
> > Component: Other
> > AssignedTo: scsi_drivers-other@kernel-bugs.osdl.org
> > ReportedBy: txtoxtox285@googlemail.com
> > Regression: No
> >
> >
> > Created an attachment (id=20685)
> > --> (http://bugzilla.kernel.org/attachment.cgi?id=20685)
> > Stack trace on program kill (2.6.28.9)
> >
> > I am experimenting with CD audio extraction. I use the SCSI Generic driver for
> > this.
> >
> > My test program uses read() and write() (instead of ioctl) to send requests to
> > the driver and receive responses. I use SG_FLAG_DIRECT_IO.
> >
> > When I kill my program (because I don't want to wait until it has ripped the
> > entire CD), I am often rewarded with messages like "BUG: sleeping function
> > called from invalid context at linux-2.6.28.9/include/linux/pagemap.h:347". I
> > have attached typical stack trace.
> >
> > Another case when I hit this BUG is when I set a time out and the CD drive
> > doesn't respond fast enough. A stack trace is attached.
>
> > [34215.786870] BUG: sleeping function called from invalid context at /mnt/var-pub/src/linux-2.6.28.9/include/linux/pagemap.h:347
> > [34215.786880] in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper
> > [34215.786886] Pid: 0, comm: swapper Not tainted 2.6.28.9 #1
> > [34215.786890] Call Trace:
> > [34215.786894] <IRQ> [<ffffffff8026c4cc>] set_page_dirty_lock+0x1a/0x45
> > [34215.786911] [<ffffffff802ae17d>] bio_unmap_user+0x1e/0x4a
> > [34215.786920] [<ffffffff802e876b>] __blk_rq_unmap_user+0x14/0x20
> > [34215.786928] [<ffffffff80210852>] pit_next_event+0x2e/0x49
> > [34215.786934] [<ffffffff802e8795>] blk_rq_unmap_user+0x1e/0x4b
> > [34215.786965] [<ffffffffa0163475>] sg_finish_rem_req+0x6d/0x88 [sg]
> > [34215.786979] [<ffffffffa0164ef3>] sg_rq_end_io+0x131/0x205 [sg]
> > [34215.786986] [<ffffffff802e5c1f>] end_that_request_last+0x58/0x194
> > [34215.786992] [<ffffffff802e5e00>] blk_end_io+0x48/0x7d
> > [34215.787019] [<ffffffffa0026bef>] scsi_next_command+0x219/0x283 [scsi_mod]
> > [34215.787039] [<ffffffffa00279b1>] scsi_io_completion+0x181/0x53b [scsi_mod]
> > [34215.787047] [<ffffffff802e9737>] blk_done_softirq+0x5f/0x6d
> > [34215.787054] [<ffffffff80230787>] __do_softirq+0x5e/0xf8
> > [34215.787061] [<ffffffff8020ca8c>] call_softirq+0x1c/0x28
> > [34215.787067] [<ffffffff8020d6bc>] do_softirq+0x2c/0x68
> > [34215.787073] [<ffffffff80230696>] irq_exit+0x36/0x82
> > [34215.787079] [<ffffffff8020d79e>] do_IRQ+0xa6/0xb8
> > [34215.787085] [<ffffffff8020c256>] ret_from_intr+0x0/0xa
> > [34215.787088] <EOI> [<ffffffff8034f648>] menu_reflect+0x0/0x6d
> > [34215.787112] [<ffffffffa0147d51>] acpi_idle_enter_simple+0x170/0x1d6 [processor]
> > [34215.787127] [<ffffffffa0147d47>] acpi_idle_enter_simple+0x166/0x1d6 [processor]
> > [34215.787134] [<ffffffff8034eb32>] cpuidle_idle_call+0x73/0xb1
> > [34215.787140] [<ffffffff8020ac2a>] cpu_idle+0x3c/0x73
>
> Argh. sg_finish_rem_req() is called from interrupt context. But
> blk_rq_unmap_user() can run
> __bio_unmap_user()->set_page_dirty_lock()->lock_page(), which can call
> schedule(). If it does call schedule(), the machine will crash.
>
> afacit, blk_rq_unmap_user() has always been a can-sleep function, and
> this is a regression caused by
I think that I've already fixed this bug. The patch has been in James'
tree. It will be backported to stable trees once the patch is merged
into mainline.
Sorry about the bug.
^ permalink raw reply [flat|nested] 13+ messages in thread