Linux 4.16 compat: get_disk_and_module()

As of torvalds/linux@fb6d47a, get_disk() is now get_disk_and_module(). Add a configure check to determine if we need to use get_disk_and_module(). Reviewed-by: loli10K <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Giuseppe Di Natale <[email protected]> Closes openzfs#7264
tonyhutter · Mar 6, 2018 · a2ec500 · a2ec500
1 parent 33e0901
commit a2ec500
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Showing 4 changed files with 29 additions and 1 deletion.
diff --git a/config/kernel-get-disk-and-module.m4 b/config/kernel-get-disk-and-module.m4
@@ -0,0 +1,19 @@
+dnl #
+dnl # 4.16 API change
+dnl # Verify if get_disk_and_module() symbol is available.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_GET_DISK_AND_MODULE],
+	[AC_MSG_CHECKING([whether get_disk_and_module() is available])
+	ZFS_LINUX_TRY_COMPILE_SYMBOL([
+		#include <linux/genhd.h>
+	], [
+		struct gendisk *disk = NULL;
+		(void) get_disk_and_module(disk);
+	], [get_disk_and_module], [block/genhd.c], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_GET_DISK_AND_MODULE,
+		    1, [get_disk_and_module() is available])
+	], [
+		AC_MSG_RESULT(no)
+	])
+])
diff --git a/config/kernel.m4 b/config/kernel.m4
@@ -40,6 +40,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
 	ZFS_AC_KERNEL_BLK_QUEUE_MAX_SEGMENTS
 	ZFS_AC_KERNEL_BLK_QUEUE_HAVE_BIO_RW_UNPLUG
 	ZFS_AC_KERNEL_BLK_QUEUE_HAVE_BLK_PLUG
+	ZFS_AC_KERNEL_GET_DISK_AND_MODULE
 	ZFS_AC_KERNEL_GET_DISK_RO
 	ZFS_AC_KERNEL_GET_GENDISK
 	ZFS_AC_KERNEL_HAVE_BIO_SET_OP_ATTRS

diff --git a/include/linux/blkdev_compat.h b/include/linux/blkdev_compat.h
@@ -139,6 +139,14 @@ blk_queue_set_read_ahead(struct request_queue *q, unsigned long ra_pages)
 #endif
 }
 
+#ifndef HAVE_GET_DISK_AND_MODULE
+static inline struct kobject *
+get_disk_and_module(struct gendisk *disk)
+{
+	return (get_disk(disk));
+}
+#endif
+
 #ifndef HAVE_GET_DISK_RO
 static inline int
 get_disk_ro(struct gendisk *disk)

diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
@@ -1559,7 +1559,7 @@ zvol_probe(dev_t dev, int *part, void *arg)
 	struct kobject *kobj;
 
 	zv = zvol_find_by_dev(dev);
-	kobj = zv ? get_disk(zv->zv_disk) : NULL;
+	kobj = zv ? get_disk_and_module(zv->zv_disk) : NULL;
 	ASSERT(zv == NULL || MUTEX_HELD(&zv->zv_state_lock));
 	if (zv)
 		mutex_exit(&zv->zv_state_lock);