forked from luck/tmp_suning_uos_patched
2a1b4cf233
While a queue is being destroyed, all the blkgs are destroyed and its
->root_blkg pointer is set to NULL. If someone else starts to drain
while the queue is in this state, the following oops happens.
NULL pointer dereference at 0000000000000028
IP: [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230
PGD e4a1067 PUD b773067 PMD 0
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: cfq_iosched(-) [last unloaded: cfq_iosched]
CPU: 1 PID: 537 Comm: bash Not tainted 3.16.0-rc3-work+ #2
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
task: ffff88000e222250 ti: ffff88000efd4000 task.ti: ffff88000efd4000
RIP: 0010:[<ffffffff8144e944>] [<ffffffff8144e944>] blk_throtl_drain+0x84/0x230
RSP: 0018:ffff88000efd7bf0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff880015091450 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88000efd7c10 R08: 0000000000000000 R09: 0000000000000001
R10: ffff88000e222250 R11: 0000000000000000 R12: ffff880015091450
R13: ffff880015092e00 R14: ffff880015091d70 R15: ffff88001508fc28
FS: 00007f1332650740(0000) GS:ffff88001fa80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000028 CR3: 0000000009446000 CR4: 00000000000006e0
Stack:
ffffffff8144e8f6 ffff880015091450 0000000000000000 ffff880015091d80
ffff88000efd7c28 ffffffff8144ae2f ffff880015091450 ffff88000efd7c58
ffffffff81427641 ffff880015091450 ffffffff82401f00 ffff880015091450
Call Trace:
[<ffffffff8144ae2f>] blkcg_drain_queue+0x1f/0x60
[<ffffffff81427641>] __blk_drain_queue+0x71/0x180
[<ffffffff81429b3e>] blk_queue_bypass_start+0x6e/0xb0
[<ffffffff814498b8>] blkcg_deactivate_policy+0x38/0x120
[<ffffffff8144ec44>] blk_throtl_exit+0x34/0x50
[<ffffffff8144aea5>] blkcg_exit_queue+0x35/0x40
[<ffffffff8142d476>] blk_release_queue+0x26/0xd0
[<ffffffff81454968>] kobject_cleanup+0x38/0x70
[<ffffffff81454848>] kobject_put+0x28/0x60
[<ffffffff81427505>] blk_put_queue+0x15/0x20
[<ffffffff817d07bb>] scsi_device_dev_release_usercontext+0x16b/0x1c0
[<ffffffff810bc339>] execute_in_process_context+0x89/0xa0
[<ffffffff817d064c>] scsi_device_dev_release+0x1c/0x20
[<ffffffff817930e2>] device_release+0x32/0xa0
[<ffffffff81454968>] kobject_cleanup+0x38/0x70
[<ffffffff81454848>] kobject_put+0x28/0x60
[<ffffffff817934d7>] put_device+0x17/0x20
[<ffffffff817d11b9>] __scsi_remove_device+0xa9/0xe0
[<ffffffff817d121b>] scsi_remove_device+0x2b/0x40
[<ffffffff817d1257>] sdev_store_delete+0x27/0x30
[<ffffffff81792ca8>] dev_attr_store+0x18/0x30
[<ffffffff8126f75e>] sysfs_kf_write+0x3e/0x50
[<ffffffff8126ea87>] kernfs_fop_write+0xe7/0x170
[<ffffffff811f5e9f>] vfs_write+0xaf/0x1d0
[<ffffffff811f69bd>] SyS_write+0x4d/0xc0
[<ffffffff81d24692>] system_call_fastpath+0x16/0x1b
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.. | ||
partitions | ||
bio-integrity.c | ||
bio.c | ||
blk-cgroup.c | ||
blk-cgroup.h | ||
blk-core.c | ||
blk-exec.c | ||
blk-flush.c | ||
blk-integrity.c | ||
blk-ioc.c | ||
blk-iopoll.c | ||
blk-lib.c | ||
blk-map.c | ||
blk-merge.c | ||
blk-mq-cpu.c | ||
blk-mq-cpumap.c | ||
blk-mq-sysfs.c | ||
blk-mq-tag.c | ||
blk-mq-tag.h | ||
blk-mq.c | ||
blk-mq.h | ||
blk-settings.c | ||
blk-softirq.c | ||
blk-sysfs.c | ||
blk-tag.c | ||
blk-throttle.c | ||
blk-timeout.c | ||
blk.h | ||
bounce.c | ||
bsg-lib.c | ||
bsg.c | ||
cfq-iosched.c | ||
cmdline-parser.c | ||
compat_ioctl.c | ||
deadline-iosched.c | ||
elevator.c | ||
genhd.c | ||
ioctl.c | ||
ioprio.c | ||
Kconfig | ||
Kconfig.iosched | ||
Makefile | ||
noop-iosched.c | ||
partition-generic.c | ||
scsi_ioctl.c |