drbd/bsc-1202600_02-dax-introduce-DAX_RECOVERY_WRITE-dax-access-mode.patch

/* This patch is related with following upstream kernel commit. */

From e511c4a3d2a1f64aafc1f5df37a2ffcf7ef91b55 Mon Sep 17 00:00:00 2001
From: Jane Chu <jane.chu@oracle.com>
Date: Fri, 13 May 2022 15:10:58 -0700
Subject: [PATCH] dax: introduce DAX_RECOVERY_WRITE dax access mode

Up till now, dax_direct_access() is used implicitly for normal
access, but for the purpose of recovery write, dax range with
poison is requested.  To make the interface clear, introduce
	enum dax_access_mode {
		DAX_ACCESS,
		DAX_RECOVERY_WRITE,
	}
where DAX_ACCESS is used for normal dax access, and
DAX_RECOVERY_WRITE is used for dax recovery write.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Vivek Goyal <vgoyal@redhat.com>
Link: https://lore.kernel.org/r/165247982851.52965.11024212198889762949.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---

diff -Nupr a/drbd/drbd_dax_pmem.c b/drbd/drbd_dax_pmem.c
--- a/drbd/drbd_dax_pmem.c	2022-08-22 16:26:24.786369807 +0800
+++ b/drbd/drbd_dax_pmem.c	2022-08-22 16:26:47.706276429 +0800
@@ -39,7 +39,7 @@ static int map_superblock_for_dax(struct
 	int id;
 
 	id = dax_read_lock();
-	len = dax_direct_access(dax_dev, pgoff, want, &kaddr, &pfn_unused);
+	len = dax_direct_access(dax_dev, pgoff, want, DAX_ACCESS, &kaddr, &pfn_unused);
 	dax_read_unlock(id);
 
 	if (len < want)
@@ -100,7 +100,7 @@ int drbd_dax_map(struct drbd_backing_dev
 	int id;
 
 	id = dax_read_lock();
-	len = dax_direct_access(dax_dev, pgoff, want, &kaddr, &pfn_unused);
+	len = dax_direct_access(dax_dev, pgoff, want, DAX_ACCESS, &kaddr, &pfn_unused);
 	dax_read_unlock(id);
 
 	if (len < want)