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. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel