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| author | Milan Broz <mbroz@redhat.com> | 2008-12-12 14:50:49 +0100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-12-29 08:29:52 +0100 |
| commit | 8ae30b895805a6e2bb725b1d78b12daabd7eadfe (patch) | |
| tree | 3fbf7bd4bf0eb8928c7a2aaa5579c7e1205b1d2e /drivers | |
| parent | 14f2793958bd7878db2dc0309ed4525d6b7f1b72 (diff) | |
| download | linux-stable-8ae30b895805a6e2bb725b1d78b12daabd7eadfe.tar.gz linux-stable-8ae30b895805a6e2bb725b1d78b12daabd7eadfe.tar.bz2 linux-stable-8ae30b895805a6e2bb725b1d78b12daabd7eadfe.zip | |
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/loop.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 66cfff79938e..edbaac6c0573 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -919,6 +919,7 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) kthread_stop(lo->lo_thread); + lo->lo_queue->unplug_fn = NULL; lo->lo_backing_file = NULL; loop_release_xfer(lo); |