linux-toradex.git/drivers/cdrom/gdrom.c, branch v4.4.147

cdrom: do not call check_disk_change() inside cdrom_open()

2018-05-30T05:49:13+00:00

[ Upstream commit 2bbea6e117357d17842114c65e9a9cf2d13ae8a3 ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
#10 [ffff880078447e28] mount_fs at ffffffff81202d09
#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
#12 [ffff880078447ea8] do_mount at ffffffff81220fee
#13 [ffff880078447f28] sys_mount at ffffffff812218d6
#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
#16 [ffff880078417d00] do_last at ffffffff8120d53d
#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
#20 [ffff880078417f70] sys_open at ffffffff811fde4e
#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

gdrom: missed conversion from req->buffer

2014-04-16T20:15:24+00:00

The friendly Intel kbuild test robot reported:

drivers/cdrom/gdrom.c: In function 'gdrom_readdisk_dma':
drivers/cdrom/gdrom.c:605:3: error: 'struct request' has no member named 'buffer'

Convert that from req->buffer to bio_data(rq->bio). Apparently
my grep missed this one, and I don't build for Sega Dreamcast
enough.

Signed-off-by: Jens Axboe

drivers/cdrom/gdrom.c: remove deprecated IRQF_DISABLED

2013-12-04T02:22:17+00:00

Remove the IRQF_DISABLED flag from drivers/cdrom/gdrom.c.

It's a NOOP since 2.6.35 and it will be removed one day.

Signed-off-by: Michael Opdenacker 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Jens Axboe

drivers/cdrom/gdrom.c: fix device number leak

2013-07-03T23:07:25+00:00

Without this patch, gdrom_major will leak when gd.cd_info alloc fails.

Signed-off-by: Libo Chen 
Cc: Jens Axboe 
Acked-by: Tejun Heo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block_device_operations->release() should return void

2013-05-07T06:16:21+00:00

The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.

Signed-off-by: Al Viro

Drivers: misc: remove __dev* attributes.

2013-01-03T23:57:16+00:00

CONFIG_HOTPLUG is going away as an option.  As a result, the __dev*
markings need to be removed.

This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton 
Signed-off-by: Greg Kroah-Hartman

workqueue: deprecate flush[_delayed]_work_sync()

2012-08-20T21:51:24+00:00

flush[_delayed]_work_sync() are now spurious.  Mark them deprecated
and convert all users to flush[_delayed]_work().

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant and the regular flushes guarantee that the work item is
not pending or running on any CPU on return, so there's no reason to
use the sync flushes at all and they're going away.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo 
Cc: Russell King 
Cc: Paul Mundt 
Cc: Ian Campbell 
Cc: Jens Axboe 
Cc: Mattia Dongili 
Cc: Kent Yoder 
Cc: David Airlie 
Cc: Jiri Kosina 
Cc: Karsten Keil 
Cc: Bryan Wu 
Cc: Benjamin Herrenschmidt 
Cc: Alasdair Kergon 
Cc: Mauro Carvalho Chehab 
Cc: Florian Tobias Schandinat 
Cc: David Woodhouse 
Cc: "David S. Miller" 
Cc: linux-wireless@vger.kernel.org
Cc: Anton Vorontsov 
Cc: Sangbeom Kim 
Cc: "James E.J. Bottomley" 
Cc: Greg Kroah-Hartman 
Cc: Eric Van Hensbergen 
Cc: Takashi Iwai 
Cc: Steven Whitehouse 
Cc: Petr Vandrovec 
Cc: Mark Fasheh 
Cc: Christoph Hellwig 
Cc: Avi Kivity

block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers

2011-04-21T19:33:05+00:00

In-kernel disk event polling doesn't matter for legacy/fringe drivers
and may lead to infinite event loop if ->check_events() implementation
generates events on level condition instead of edge.

Now that block layer supports suppressing exporting unlisted events,
simply leaving disk->events cleared allows these drivers to keep the
internal revalidation behavior intact while avoiding weird
interactions with userland event handler.

Signed-off-by: Tejun Heo 
Cc: Kay Sievers 
Signed-off-by: Jens Axboe

gdrom,viocd: Convert to bdops->check_events()

2011-03-09T18:54:28+00:00

Convert gdrom and viocd from ->media_changed() to ->check_events().

It's unclear how the conditions are cleared and it's possible that it
may generate spurious events when polled.

Signed-off-by: Tejun Heo 
Cc: Jens Axboe 
Cc: Kay Sievers

gdrom: don't use flush_scheduled_work()

2010-12-24T14:59:06+00:00

flush_scheduled_work() is deprecated and scheduled to be removed.
Directly flush work on removal instead.

Signed-off-by: Tejun Heo 
Cc: Jens Axboe