linux/drivers/block
Milan Broz 8ae30b8958 loop: Do not call loop_unplug for not configured loop device.
In loop_unplug() function is expected that mapping is set
and lo->lo_backing_file is not NULL.

Unfortunately loop_set_fd() set the request queue unplug function,
but loop_clr_fd() doesn't clear that.

Loop device allows open of non-configured loop in some situations.
If the unplug on request queue is called, loop module oopses because
of missing lo_backing_file.

Simple reproducer:
	losetup /dev/loop0 /xxx
	losetup -d /dev/loop0
	dmsetup create x --table "0 1 linear /dev/loop0 0"

 EIP is at loop_unplug+0x1d/0x3b
 ...
  Call Trace:
   blk_unplug+0x57/0x5e
   dm_table_unplug_all+0x34/0x77 [dm_mod]
   destroy_inode+0x27/0x38
   generic_delete_inode+0xd5/0xd9
   iput+0x4b/0x4e
   dm_resume+0xca/0xfe [dm_mod]
   dev_suspend+0x143/0x165 [dm_mod]
   dm_ctl_ioctl+0x18e/0x1cf [dm_mod]
   dev_suspend+0x0/0x165 [dm_mod]
   dm_ctl_ioctl+0x0/0x1cf [dm_mod]
   vfs_ioctl+0x22/0x69
   do_vfs_ioctl+0x39d/0x3c7
   trace_hardirqs_on+0xb/0xd
   remove_vma+0x50/0x56
   do_munmap+0x21c/0x237
   sys_ioctl+0x2c/0x45
   sysenter_do_call+0x12/0x31

Several reports here
http://www.kerneloops.org/search.php?search=loop_unplug

Fix it by simply clear unplug function together with
removing of backing file.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29 08:29:52 +01:00
..
aoe aoe: remove private mac address format function 2008-11-25 00:40:37 -08:00
paride [PATCH] switch pf 2008-10-21 07:47:59 -04:00
amiflop.c [PATCH] switch amiflop 2008-10-21 07:47:38 -04:00
ataflop.c [PATCH] switch ataflop 2008-10-21 07:47:42 -04:00
brd.c [PATCH] switch brd 2008-10-21 07:47:44 -04:00
cciss_cmd.h cciss: switch to using hlist for command list management 2008-12-29 08:28:43 +01:00
cciss_scsi.c cciss: Fix cciss SCSI rescan code to better notice device changes 2008-10-09 08:56:18 +02:00
cciss_scsi.h cciss: Fix cciss SCSI rescan code to better notice device changes 2008-10-09 08:56:18 +02:00
cciss.c cciss: switch to using hlist for command list management 2008-12-29 08:28:43 +01:00
cciss.h cciss: switch to using hlist for command list management 2008-12-29 08:28:43 +01:00
cpqarray.c cpqarry: fix return value of cpqarray_init() 2008-11-06 15:41:17 -08:00
cpqarray.h
cryptoloop.c drivers: Remove unnecessary inclusions of asm/semaphore.h 2008-04-18 22:16:32 -04:00
DAC960.c [PATCH] switch DAC960 2008-10-21 07:47:36 -04:00
DAC960.h Fix DAC960 driver on machines which don't support 64-bit DMA 2007-09-11 17:21:19 -07:00
floppy.c Create/use more directory structure in the Documentation/ tree. 2008-11-14 17:28:53 +00:00
hd.c hd: WIN_* -> ATA_CMD_* 2008-10-10 22:39:21 +02:00
ida_cmd.h
ida_ioctl.h
Kconfig Create/use more directory structure in the Documentation/ tree. 2008-11-14 17:28:53 +00:00
loop.c loop: Do not call loop_unplug for not configured loop device. 2008-12-29 08:29:52 +01:00
Makefile move ide/legacy/hd.c to drivers/block/ 2008-07-16 20:33:47 +02:00
nbd.c nbd: tell the block layer that it is not a rotational device 2008-12-29 08:29:50 +01:00
pktcdvd.c pktcdvd: remove broken dev_t export of class devices 2008-12-10 10:03:32 -08:00
ps3disk.c block: don't depend on consecutive minor space 2008-10-09 08:56:05 +02:00
smart1,2.h
sunvdc.c sparc64: Apply const or __initdata to vio_device_id[] 2008-09-01 01:48:52 -07:00
swim3.c [PATCH] switch swim3 2008-10-21 07:48:03 -04:00
sx8.c block: replace remaining __FUNCTION__ occurrences 2008-04-21 09:51:04 +02:00
ub.c ub: stub pre_reset and post_reset to fix oops 2008-11-13 14:45:04 -08:00
umem.c Cleanup umem driver: fix most checkpatch warnings, conform to kernel 2007-12-18 08:29:28 +01:00
umem.h drivers/block/umem: trim trailing whitespace 2007-10-10 09:25:59 +02:00
viodasd.c [PATCH] switch viodasd 2008-10-21 07:48:07 -04:00
virtio_blk.c virtio_blk: set queue paravirt flag 2008-12-29 08:28:41 +01:00
xd.c [PATCH] switch xd 2008-10-21 07:48:11 -04:00
xd.h [PATCH] switch xd 2008-10-21 07:48:11 -04:00
xen-blkfront.c xen-blkfront: set queue paravirt flag 2008-12-29 08:28:41 +01:00
xsysace.c xsysace: Fix driver to use resource_size_t instead of unsigned long 2008-11-14 10:21:57 -07:00
z2ram.c [PATCH] switch z2ram 2008-10-21 07:48:17 -04:00