diff options
| author | Xuewei Zhang <xueweiz@google.com> | 2018-09-06 13:37:19 -0700 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2018-09-17 02:57:10 -0400 |
| commit | 83e32a5910772e1475d3640a429b7686695f04d1 (patch) | |
| tree | bded4bee164404584632e082179544f243791a8f /drivers/scsi/sd.c | |
| parent | adad633af7b970bfa5dd1b624a4afc83cac9b235 (diff) | |
scsi: sd: Contribute to randomness when running rotational device
Currently a scsi device won't contribute to kernel randomness when it uses
blk-mq. Since we commonly use scsi on rotational device with blk-mq, it make
sense to keep contributing to kernel randomness in these cases. This is
especially important for virtual machines.
commit b5b6e8c8d3b4 ("scsi: virtio_scsi: fix IO hang caused by automatic irq
vector affinity") made all virtio-scsi device to use blk-mq, which does not
contribute to randomness today. So for a virtual machine only having
virtio-scsi disk (which is common), it will simple stop getting randomness
from its disks in today's implementation.
With this patch, if the above VM has rotational virtio-scsi device, then it
can still benefit from the entropy generated from the disk.
Reported-by: Xuewei Zhang <xueweiz@google.com>
Signed-off-by: Xuewei Zhang <xueweiz@google.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/sd.c')
| -rw-r--r-- | drivers/scsi/sd.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index b79b366a94f7..5e4f10d28065 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2959,6 +2959,9 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp) if (rot == 1) { blk_queue_flag_set(QUEUE_FLAG_NONROT, q); blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q); + } else { + blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); + blk_queue_flag_set(QUEUE_FLAG_ADD_RANDOM, q); } if (sdkp->device->type == TYPE_ZBC) { |