mirror of
https://github.com/torvalds/linux.git
synced 2026-09-25 21:21:09 -04:00
Petr Uzel
fd51469fb6
Following steps lead to deadlock in kernel:
dd if=/dev/zero of=img bs=512 count=1000
losetup -f img
mkfs.ext2 /dev/loop0
mount -t ext2 -o loop /dev/loop0 mnt
umount mnt/
Stacktrace:
[<c102ec04>] irq_exit+0x36/0x59
[<c101502c>] smp_apic_timer_interrupt+0x6b/0x75
[<c127f639>] apic_timer_interrupt+0x31/0x38
[<c101df88>] mutex_spin_on_owner+0x54/0x5b
[<fe2250e9>] lo_release+0x12/0x67 [loop]
[<c10c4eae>] __blkdev_put+0x7c/0x10c
[<c10a4da5>] fput+0xd5/0x1aa
[<fe2250cf>] loop_clr_fd+0x1a9/0x1b1 [loop]
[<fe225110>] lo_release+0x39/0x67 [loop]
[<c10c4eae>] __blkdev_put+0x7c/0x10c
[<c10a59d9>] deactivate_locked_super+0x17/0x36
[<c10b6f37>] sys_umount+0x27e/0x2a5
[<c10b6f69>] sys_oldumount+0xb/0xe
[<c1002897>] sysenter_do_call+0x12/0x26
[<ffffffff>] 0xffffffff
Regression since 2a48fc0ab2, which introduced the private
loop_mutex as part of the BKL removal process.
As per [1], the mutex can be safely removed.
[1] http://www.gossamer-threads.com/lists/linux/kernel/1341930
Addresses: https://bugzilla.novell.com/show_bug.cgi?id=669394
Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=29172
Signed-off-by: Petr Uzel <[email protected]>
Cc: [email protected]
Reviewed-by: Nikanth Karthikesan <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>