Re: block: Fix cloning of requests with a special payload

On Wed, Jun 27 2018 at 3:55pm -0400, Bart Van Assche bart.vanassche@wdc.com wrote:

This patch avoids that removing a path controlled by the dm-mpath driver while mkfs is running triggers the following kernel bug:

kernel BUG at block/blk-core.c:3347!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 20 PID: 24369 Comm: mkfs.ext4 Not tainted 4.18.0-rc1-dbg+ #2
RIP: 0010:blk_end_request_all+0x68/0x70
Call Trace:
 <IRQ>
 dm_softirq_done+0x326/0x3d0 [dm_mod]
 blk_done_softirq+0x19b/0x1e0
 __do_softirq+0x128/0x60d
 irq_exit+0x100/0x110
 smp_call_function_single_interrupt+0x90/0x330
 call_function_single_interrupt+0xf/0x20
 </IRQ>

Fixes: f9d03f96b988 ("block: improve handling of the magic discard payload") Signed-off-by: Bart Van Assche bart.vanassche@wdc.com Cc: Christoph Hellwig hch@lst.de Cc: Mike Snitzer snitzer@redhat.com Cc: Ming Lei ming.lei@redhat.com Cc: Hannes Reinecke hare@suse.com Cc: Johannes Thumshirn jthumshirn@suse.de Cc: stable@vger.kernel.org

Acked-by: Mike Snitzer snitzer@redhat.com