null_blk: Always check queue mode setting from configfs
Make sure to check device queue mode in the null_validate_conf() and
return error for NULL_Q_RQ as we don't allow legacy I/O path, without
this patch we get OOPs when queue mode is set to 1 from configfs,
following are repro steps :-
modprobe null_blk nr_devices=0
mkdir config/nullb/nullb0
echo 1 > config/nullb/nullb0/memory_backed
echo 4096 > config/nullb/nullb0/blocksize
echo 20480 > config/nullb/nullb0/size
echo 1 > config/nullb/nullb0/queue_mode
echo 1 > config/nullb/nullb0/power
Entering kdb (current=0xffff88810acdd080, pid 2372) on processor 42 Oops: (null)
due to oops @ 0xffffffffc041c329
CPU: 42 PID: 2372 Comm: sh Tainted: G O N 6.3.0-rc5lblk+ #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:null_add_dev.part.0+0xd9/0x720 [null_blk]
Code: 01 00 00 85 d2 0f 85 a1 03 00 00 48 83 bb 08 01 00 00 00 0f 85 f7 03 00 00 80 bb 62 01 00 00 00 48 8b 75 20 0f 85 6d 02 00 00 <48> 89 6e 60 48 8b 75 20 bf 06 00 00 00 e8 f5 37 2c c1 48 8b 75 20
RSP: 0018:
ffffc900052cbde0 EFLAGS:
00010246
RAX:
0000000000000001 RBX:
ffff88811084d800 RCX:
0000000000000001
RDX:
0000000000000000 RSI:
0000000000000000 RDI:
ffff888100042e00
RBP:
ffff8881053d8200 R08:
ffffc900052cbd68 R09:
ffff888105db2000
R10:
0000000000000001 R11:
0000000000000000 R12:
0000000000000002
R13:
ffff888104765200 R14:
ffff88810eec1748 R15:
ffff88810eec1740
FS:
00007fd445fd1740(0000) GS:
ffff8897dfc80000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
0000000000000060 CR3:
0000000166a00000 CR4:
0000000000350ee0
DR0:
ffffffff8437a488 DR1:
ffffffff8437a489 DR2:
ffffffff8437a48a
DR3:
ffffffff8437a48b DR6:
00000000ffff0ff0 DR7:
0000000000000400
Call Trace:
<TASK>
nullb_device_power_store+0xd1/0x120 [null_blk]
configfs_write_iter+0xb4/0x120
vfs_write+0x2ba/0x3c0
ksys_write+0x5f/0xe0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fd4460c57a7
Code: 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:
00007ffd3792a4a8 EFLAGS:
00000246 ORIG_RAX:
0000000000000001
RAX:
ffffffffffffffda RBX:
0000000000000002 RCX:
00007fd4460c57a7
RDX:
0000000000000002 RSI:
000055b43c02e4c0 RDI:
0000000000000001
RBP:
000055b43c02e4c0 R08:
000000000000000a R09:
00007fd44615b4e0
R10:
00007fd44615b3e0 R11:
0000000000000246 R12:
0000000000000002
R13:
00007fd446198520 R14:
0000000000000002 R15:
00007fd446198700
</TASK>
Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Link: https://lore.kernel.org/r/20230416220339.43845-1-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>