linux-kernel - [PATCH 12/17] ublk: don't access ublk_queue in ublk_config_io

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250918014953.297897-13-csander@purestorage.com>
Date: Wed, 17 Sep 2025 19:49:48 -0600
From: Caleb Sander Mateos <csander@...estorage.com>
To: Ming Lei <ming.lei@...hat.com>,
	Jens Axboe <axboe@...nel.dk>
Cc: linux-block@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Caleb Sander Mateos <csander@...estorage.com>
Subject: [PATCH 12/17] ublk: don't access ublk_queue in ublk_config_io_buf()

For ublk servers with many ublk queues, accessing the ublk_queue in
ublk_config_io_buf() is a frequent cache miss. Get the flags
from the ublk_device instead, which is accessed earlier in
ublk_ch_uring_cmd_local().

Signed-off-by: Caleb Sander Mateos <csander@...estorage.com>
---
 drivers/block/ublk_drv.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 9c6045e6d03b..9535382f9f8e 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -2079,15 +2079,15 @@ ublk_fill_io_cmd(struct ublk_io *io, struct io_uring_cmd *cmd)
 
 	return req;
 }
 
 static inline int
-ublk_config_io_buf(const struct ublk_queue *ubq, struct ublk_io *io,
+ublk_config_io_buf(const struct ublk_device *ub, struct ublk_io *io,
 		   struct io_uring_cmd *cmd, unsigned long buf_addr,
 		   u16 *buf_idx)
 {
-	if (ublk_support_auto_buf_reg(ubq))
+	if (ublk_dev_support_auto_buf_reg(ub))
 		return ublk_handle_auto_buf_reg(io, cmd, buf_idx);
 
 	io->addr = buf_addr;
 	return 0;
 }
@@ -2231,11 +2231,11 @@ static int ublk_fetch(struct io_uring_cmd *cmd, struct ublk_queue *ubq,
 	}
 
 	WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV);
 
 	ublk_fill_io_cmd(io, cmd);
-	ret = ublk_config_io_buf(ubq, io, cmd, buf_addr, NULL);
+	ret = ublk_config_io_buf(ub, io, cmd, buf_addr, NULL);
 	if (ret)
 		goto out;
 
 	WRITE_ONCE(io->task, get_task_struct(current));
 	ublk_mark_io_ready(ub);
@@ -2385,11 +2385,11 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd,
 		ret = ublk_check_commit_and_fetch(ubq, io, addr);
 		if (ret)
 			goto out;
 		io->res = result;
 		req = ublk_fill_io_cmd(io, cmd);
-		ret = ublk_config_io_buf(ubq, io, cmd, addr, &buf_idx);
+		ret = ublk_config_io_buf(ub, io, cmd, addr, &buf_idx);
 		compl = ublk_need_complete_req(ubq, io);
 
 		/* can't touch 'ublk_io' any more */
 		if (buf_idx != UBLK_INVALID_BUF_IDX)
 			io_buffer_unregister_bvec(cmd, buf_idx, issue_flags);
@@ -2406,11 +2406,11 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd,
 		 * ublk_get_data() may fail and fallback to requeue, so keep
 		 * uring_cmd active first and prepare for handling new requeued
 		 * request
 		 */
 		req = ublk_fill_io_cmd(io, cmd);
-		ret = ublk_config_io_buf(ubq, io, cmd, addr, NULL);
+		ret = ublk_config_io_buf(ub, io, cmd, addr, NULL);
 		WARN_ON_ONCE(ret);
 		if (likely(ublk_get_data(ubq, io, req))) {
 			__ublk_prep_compl_io_cmd(io, req);
 			return UBLK_IO_RES_OK;
 		}
-- 
2.45.2