From: Caleb Sander Mateos <csander@purestorage.com>
Date: Thu, 18 Sep 2025 01:49:41 +0000 (-0600)
Subject: ublk: don't dereference ublk_queue in ublk_ch_uring_cmd_local()
X-Git-Tag: v6.18-rc1~136^2~20
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5125535f90564117506d926d0de92c4c2622b720;p=thirdparty%2Fkernel%2Flinux.git

ublk: don't dereference ublk_queue in ublk_ch_uring_cmd_local()

For ublk servers with many ublk queues, accessing the ublk_queue to
handle a ublk command is a frequent cache miss. Get the queue depth from
the ublk_device instead, which is accessed just before.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 04b8613ce623f..58f688eac7420 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -2333,7 +2333,7 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd,
 
 	ubq = ublk_get_queue(ub, q_id);
 
-	if (tag >= ubq->q_depth)
+	if (tag >= ub->dev_info.queue_depth)
 		goto out;
 
 	io = &ubq->ios[tag];