From 980aca470c229b2fd238076e9c3c4d285c20279a Mon Sep 17 00:00:00 2001
From: Ryan Lahfa <ryan@lahfa.xyz>
Date: Fri, 21 Jun 2024 00:54:58 +0200
Subject: [PATCH] Linux 6.9 compat: blk_alloc_disk takes 2 args

Now, it takes queue limits, this is a trivial implementation
with no queue limits, implementing proper queue limits is left as an
exercise to the reader.

Signed-off-by: Ryan Lahfa <ryan@lahfa.xyz>
---
 config/kernel-make-request-fn.m4 | 50 +++++++++++++++++++++++---------
 module/os/linux/zfs/zvol_os.c    |  4 +++
 2 files changed, 40 insertions(+), 14 deletions(-)

diff --git a/config/kernel-make-request-fn.m4 b/config/kernel-make-request-fn.m4
index 4d20dd45c4..ef79612f9d 100644
--- a/config/kernel-make-request-fn.m4
+++ b/config/kernel-make-request-fn.m4
@@ -50,6 +50,13 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_MAKE_REQUEST_FN], [
 		disk = blk_alloc_disk(NUMA_NO_NODE);
 	])
 
+	ZFS_LINUX_TEST_SRC([blk_alloc_disk_2args], [
+		#include <linux/blkdev.h>
+	],[
+		struct gendisk *disk __attribute__ ((unused));
+		disk = blk_alloc_disk(NULL, NUMA_NO_NODE);
+	])
+
 	ZFS_LINUX_TEST_SRC([blk_cleanup_disk], [
 		#include <linux/blkdev.h>
 	],[
@@ -71,30 +78,45 @@ AC_DEFUN([ZFS_AC_KERNEL_MAKE_REQUEST_FN], [
 		AC_DEFINE(HAVE_SUBMIT_BIO_IN_BLOCK_DEVICE_OPERATIONS, 1,
 		    [submit_bio is member of struct block_device_operations])
 
+		dnl
+		dnl # Linux 6.9 API change
+		dnl # blk_alloc_disk() takes 2 arguments:
+		dnl # a queue limit and NUMA node ID.
 		dnl #
-		dnl # Linux 5.14 API Change:
-		dnl # blk_alloc_queue() + alloc_disk() combo replaced by
-		dnl # a single call to blk_alloc_disk().
-		dnl #
-		AC_MSG_CHECKING([whether blk_alloc_disk() exists])
-		ZFS_LINUX_TEST_RESULT([blk_alloc_disk], [
+		AC_MSG_CHECKING([whether blk_alloc_disk() takes 2 args])
+		ZFS_LINUX_TEST_RESULT([blk_alloc_disk_2args], [
 			AC_MSG_RESULT(yes)
 			AC_DEFINE([HAVE_BLK_ALLOC_DISK], 1, [blk_alloc_disk() exists])
+			AC_DEFINE([HAVE_BLK_ALLOC_DISK_2ARGS], 1, [blk_alloc_disk() takes 2 args])
+			dnl # put_disk() should be used in 6.9.
+		], [
+			AC_MSG_RESULT(no)
 
 			dnl #
-			dnl # 5.20 API change,
-			dnl # Removed blk_cleanup_disk(), put_disk() should be used.
+			dnl # Linux 5.14 API Change:
+			dnl # blk_alloc_queue() + alloc_disk() combo replaced by
+			dnl # a single call to blk_alloc_disk().
 			dnl #
-			AC_MSG_CHECKING([whether blk_cleanup_disk() exists])
-			ZFS_LINUX_TEST_RESULT([blk_cleanup_disk], [
+			AC_MSG_CHECKING([whether blk_alloc_disk() exists])
+			ZFS_LINUX_TEST_RESULT([blk_alloc_disk], [
 				AC_MSG_RESULT(yes)
-				AC_DEFINE([HAVE_BLK_CLEANUP_DISK], 1,
-				    [blk_cleanup_disk() exists])
+				AC_DEFINE([HAVE_BLK_ALLOC_DISK], 1, [blk_alloc_disk() exists])
+
+				dnl #
+				dnl # 5.20 API change,
+				dnl # Removed blk_cleanup_disk(), put_disk() should be used.
+				dnl #
+				AC_MSG_CHECKING([whether blk_cleanup_disk() exists])
+				ZFS_LINUX_TEST_RESULT([blk_cleanup_disk], [
+					AC_MSG_RESULT(yes)
+					AC_DEFINE([HAVE_BLK_CLEANUP_DISK], 1,
+							[blk_cleanup_disk() exists])
+				], [
+					AC_MSG_RESULT(no)
+				])
 			], [
 				AC_MSG_RESULT(no)
 			])
-		], [
-			AC_MSG_RESULT(no)
 		])
 	],[
 		AC_MSG_RESULT(no)
diff --git a/module/os/linux/zfs/zvol_os.c b/module/os/linux/zfs/zvol_os.c
index 87288190e7..92d1189d0e 100644
--- a/module/os/linux/zfs/zvol_os.c
+++ b/module/os/linux/zfs/zvol_os.c
@@ -874,7 +874,11 @@ zvol_alloc(dev_t dev, const char *name)
 
 #ifdef HAVE_SUBMIT_BIO_IN_BLOCK_DEVICE_OPERATIONS
 #ifdef HAVE_BLK_ALLOC_DISK
+#ifdef HAVE_BLK_ALLOC_DISK_2ARGS
+	zso->zvo_disk = blk_alloc_disk(NULL, NUMA_NO_NODE);
+#else
 	zso->zvo_disk = blk_alloc_disk(NUMA_NO_NODE);
+#endif
 	if (zso->zvo_disk == NULL)
 		goto out_kmem;