On 3/22/19 11:43 PM, Martin Wilck wrote:
Currently, an empty disk->events field tells the block layer not to forward
media change events to user space. This was done in
commit 7c88a168da80 ("block: don't propagate unlisted DISK_EVENTs to userland")
in order to avoid events from "fringe" drivers to be forwarded to user
space. By doing so, the block layer lost the information which events were
supported by a particular block device, and most importantly, whether or
not a given device supports media change events at all.
Prepare for not interpreting the "events" field this way in the future any
more. This is done by adding two flag bits that can be set to have the
device treated like one that has the "events" field set to a non-zero value
before. This applies only to the sd and sr drivers, which are changed to
set the new flags.
The new flags are DISK_EVENT_FLAG_POLL to enforce polling of the device for
synchronous events, and DISK_EVENT_FLAG_UEVENT to tell the blocklayer to
generate udev events from kernel events. They can easily be fit in the int
reserved for event bits.
This patch doesn't change behavior.
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
block/genhd.c | 15 ++++++++++-----
drivers/scsi/sd.c | 3 ++-
drivers/scsi/sr.c | 3 ++-
include/linux/genhd.h | 7 +++++++
4 files changed, 21 insertions(+), 7 deletions(-)
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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HRB 21284 (AG Nürnberg)
