I tested it on 3.14-rc5. I will checkout the latest kernel and test it on my system for this bug. Thanks Zhenhua -----Original Message----- From: Mike Snitzer [mailto:snitzer@xxxxxxxxxx] Sent: Wednesday, May 28, 2014 11:03 PM To: Li, Zhen-Hua Cc: linux-kernel@xxxxxxxxxxxxxxx; Alasdair Kergon; dm-devel@xxxxxxxxxx; Neil Brown; linux-raid@xxxxxxxxxxxxxxx Subject: Re: [PATCH 1/1] driver/md/block: Alloc space for member flush_rq On Wed, May 28 2014 at 2:22am -0400, Li, Zhen-Hua <zhen-hual@xxxxxx> wrote: > This patch is trying to fix a kernel crash bug. > > When kernel boots on a HP large system, it crashes. > The reason is when blk_rq_init is called, the second parameter rq , which > is a member as q->flush_rq, is NULL. Kernel does not allocate space for it. > > This fix adds an alloc for flush_rq member when request_queue is created in > struct mapped_device *alloc_dev(int minor); > > Bug Details: > Error message: > > [ 62.931942] BUG: unable to handle kernel NULL pointer dereference at (null) > [ 62.931949] IP: [<ffffffff812b3f30>] blk_rq_init+0x40/0x160^M > [ 62.931949] PGD 0 ^M > [ 62.931951] Oops: 0002 [#1] SMP You didn't specify which kernel you're running. But this was fixed for v3.15-rc6 via linux.git commit 7982e90c3a5 ("block: fix q->flush_rq NULL pointer crash on dm-mpath flush"). And then there was the follow-on fix from linux.git commit 708f04d2ab ("block: free q->flush_rq in blk_init_allocated_queue error paths") So all this is to say: Nack to your patch, we've already fixed the issue differently. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
