Hello Paolo,
If I enable the BFQ scheduler for a dm-mpath device then a kernel oops
appears (see also below). This happens systematically with Linus' tree from
this morning (commit 54ce685cae30) merged with Jens' for-linus branch (commit
a78773906147 ("block, bfq: add requeue-request hook")) and for-next branch
(commit 88455ad7f928). Is this a known issue?
Thanks,
Bart.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000200
IP: rb_erase+0x284/0x380
PGD 0 P4D 0
Oops: 0002 [#1] PREEMPT SMP
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G W 4.15.0-dbg+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.0.0-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:rb_erase+0x284/0x380
Call Trace:
<IRQ>
elv_rb_del+0x20/0x30
bfq_remove_request+0x8d/0x2e0 [bfq]
bfq_finish_requeue_request+0x2bb/0x390 [bfq]
blk_mq_free_request+0x51/0x170
dm_softirq_done+0xd5/0x240 [dm_mod]
flush_smp_call_function_queue+0x92/0x140
smp_call_function_single_interrupt+0x47/0x2b0
call_function_single_interrupt+0xa2/0xb0
</IRQ>
