On Thu, 26 Mar 2009 07:49:52 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxx 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@xxxxxxxxxxxxxxxxxxxx > > ReportedBy: txtoxtox285@xxxxxxxxxxxxxx > > 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. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
