linux/drivers/block
Sergey Senozhatsky ee71a96867 loop: queue_lock NULL pointer derefence in blk_throtl_exit
Performing
$ sudo mount -o loop -o umask=0 /dev/sdb1 /mnt/
mount: wrong fs type, bad option, bad superblock on /dev/loop0,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

$ sudo modprobe -r loop

results in oops:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
 IP: [<ffffffff812479d4>] do_raw_spin_lock+0x14/0x122
 Process modprobe (pid: 6189, threadinfo ffff88009a898000, task ffff880154a88000)
 Call Trace:
  [<ffffffff81486788>] _raw_spin_lock_irq+0x4a/0x51
  [<ffffffff8123404b>] ? blk_throtl_exit+0x3b/0xa0
  [<ffffffff8105b120>] ? cancel_delayed_work_sync+0xd/0xf
  [<ffffffff8123404b>] blk_throtl_exit+0x3b/0xa0
  [<ffffffff81229bc8>] blk_release_queue+0x21/0x65
  [<ffffffff8123bb06>] kobject_release+0x51/0x66
  [<ffffffff8123bab5>] ? kobject_release+0x0/0x66
  [<ffffffff8123ce1e>] kref_put+0x43/0x4d
  [<ffffffff8123ba27>] kobject_put+0x47/0x4b
  [<ffffffff8122717c>] blk_cleanup_queue+0x56/0x5b
  [<ffffffffa01c3824>] loop_exit+0x68/0x844 [loop]
  [<ffffffff8107cccc>] sys_delete_module+0x1e8/0x25b
  [<ffffffff814864c9>] ? trace_hardirqs_on_thunk+0x3a/0x3f
  [<ffffffff81002112>] system_call_fastpath+0x16/0x1b

because of an attempt to acquire NULL queue_lock.
I added the same lines as in blk_queue_make_request -
index 44e18c0..49e6a54 100644`fall back to embedded per-queue lock'.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-19 08:25:02 -07:00
..
aoe Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-11-14 11:57:05 -08:00
drbd Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:45:01 -08:00
paride Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
amiflop.c block: fix amiga and atari floppy driver compile warning 2010-11-15 19:32:43 +01:00
ataflop.c block: fix amiga and atari floppy driver compile warning 2010-11-15 19:32:43 +01:00
brd.c Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block 2010-10-22 17:07:18 -07:00
cciss_cmd.h cciss: reinstate proper FIFO order of command queue list 2011-01-10 21:50:33 +01:00
cciss_scsi.c SCSI host lock push-down 2010-11-16 13:33:23 -08:00
cciss_scsi.h cciss: remove C99-style comments 2010-02-22 13:44:45 +01:00
cciss.c Merge branch 'for-2.6.38/drivers' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:50:24 -08:00
cciss.h Merge branch 'for-2.6.38/drivers' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:50:24 -08:00
cpqarray.c block: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:10 +02:00
cpqarray.h
cryptoloop.c drivers: Remove unnecessary inclusions of asm/semaphore.h 2008-04-18 22:16:32 -04:00
DAC960.c Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl 2010-10-22 10:52:56 -07:00
DAC960.h
floppy.c Merge branch 'for-2.6.38/drivers' of git://git.kernel.dk/linux-2.6-block 2011-01-13 10:50:24 -08:00
hd.c block: remove wrappers for request type/flags 2010-08-07 18:17:56 +02:00
ida_cmd.h
ida_ioctl.h
Kconfig xen: separate out frontend xenbus 2011-01-05 16:29:17 -05:00
loop.c loop: queue_lock NULL pointer derefence in blk_throtl_exit 2011-01-19 08:25:02 -07:00
Makefile drivers/block/Makefile: replace the use of <module>-objs with <module>-y 2011-01-19 08:25:02 -07:00
mg_disk.c block: switch s390 tape_block and mg_disk to elevator_change() 2010-08-23 14:02:44 +02:00
nbd.c block: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:10 +02:00
osdblk.c block: remove spurious uses of REQ_HARDBARRIER 2010-09-10 12:35:36 +02:00
pktcdvd.c block: make blkdev_get/put() handle exclusive access 2010-11-13 11:55:17 +01:00
ps3disk.c Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block 2010-10-22 17:07:18 -07:00
ps3vram.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
rbd_types.h rbd: introduce rados block device (rbd), based on libceph 2010-10-20 15:38:13 -07:00
rbd.c rbd: fix cleanup when trying to mount inexistent image 2011-01-12 15:15:18 -08:00
smart1,2.h
sunvdc.c block: Consolidate phys_segment and hw_segment limits 2010-02-26 13:58:08 +01:00
swim_asm.S m68k: mac - Add SWIM floppy support 2009-03-26 21:15:27 +01:00
swim.c block: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:10 +02:00
swim3.c block: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:10 +02:00
sx8.c block: Consolidate phys_segment and hw_segment limits 2010-02-26 13:58:08 +01:00
ub.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 2010-10-22 20:30:48 -07:00
umem.c block: unify flags for struct bio and struct request 2010-08-07 18:20:39 +02:00
umem.h
viodasd.c block: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:10 +02:00
virtio_blk.c Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block 2010-10-22 17:07:18 -07:00
xd.c block: autoconvert trivial BKL users to private mutex 2010-10-05 15:01:10 +02:00
xd.h [PATCH] switch xd 2008-10-21 07:48:11 -04:00
xen-blkfront.c Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2011-01-07 16:58:04 -08:00
xsysace.c Merge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6 2010-10-25 08:19:14 -07:00
z2ram.c drivers/block/z2ram.c: correct printing of sector_t 2010-10-28 06:15:26 -06:00