android_kernel_samsung_msm8976/drivers/s390
Mike Snitzer b636eb75ff UPSTREAM: block: disable entropy contributions for nonrot devices
(cherry picked from commit b277da0a8a594308e17881f4926879bd5fca2a2d)

Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set
QUEUE_FLAG_NONROT.

Historically, all block devices have automatically made entropy
contributions.  But as previously stated in commit e2e1a148 ("block: add
sysfs knob for turning off disk entropy contributions"):
    - On SSD disks, the completion times aren't as random as they
      are for rotational drives. So it's questionable whether they
      should contribute to the random pool in the first place.
    - Calling add_disk_randomness() has a lot of overhead.

There are more reliable sources for randomness than non-rotational block
devices.  From a security perspective it is better to err on the side of
caution than to allow entropy contributions from unreliable "random"
sources.

Change-Id: Iaace159bea0e9245e6825cccd4f6a1152a166ce1
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2019-07-27 21:47:56 +02:00
..
block
char
cio
crypto
kvm
net
scsi
Makefile