Re: [PATCH v2 3/4] block: add IOC_PR_READ_KEYS ioctl

From: Hannes Reinecke

Date: Thu Nov 27 2025 - 13:06:10 EST


On 11/27/25 16:54, Stefan Hajnoczi wrote:
Add a Persistent Reservations ioctl to read the list of currently
registered reservation keys. This calls the pr_ops->read_keys() function
that was previously added in commit c787f1baa503 ("block: Add PR
callouts for read keys and reservation") but was only used by the
in-kernel SCSI target so far.

The IOC_PR_READ_KEYS ioctl is necessary so that userspace applications
that rely on Persistent Reservations ioctls have a way of inspecting the
current state. Cluster managers and validation tests need this
functionality.

Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
---
include/uapi/linux/pr.h | 7 +++++
block/ioctl.c | 59 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 66 insertions(+)

Reviewed-by: Hannes Reinecke <hare@xxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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