File 0003-bcache-tools-convert-writeback-to-writethrough-mode-.patch of Package bcache-tools.28447

From 33b90323056f65225c5b557d7f578b7f37abee3c Mon Sep 17 00:00:00 2001
From: Coly Li <colyli@suse.de>
Date: Sat, 16 May 2020 21:57:17 +0800
Subject: [PATCH 03/17] bcache-tools: convert writeback to writethrough mode
 for zoned backing device
Git-commit: 33b90323056f65225c5b557d7f578b7f37abee3c
Patch-mainline: bcache-tools-1.1
References: jsc#SLE-9807

Currently bcache does not support writeback cache mode for zoned device
as backing device.

If the backing device is zoned device, and cache mode is explicitly set
to writeback mode, a information will be print to terminal,
  "Zoned device <device name> detected: convert to writethrough mode."
Then the cache mode will be automatically converted to writethrough,
which is the default cache mode of bcache-tools.

Signed-off-by: Coly Li <colyli@suse.de>
---
 make.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/make.c b/make.c
index c1090a6..cc76863 100644
--- a/make.c
+++ b/make.c
@@ -378,6 +378,19 @@ static void write_sb(char *dev, unsigned int block_size,
 		SET_BDEV_CACHE_MODE(&sb, writeback ?
 			CACHE_MODE_WRITEBACK : CACHE_MODE_WRITETHROUGH);
 
+		/*
+		 * Currently bcache does not support writeback mode for
+		 * zoned device as backing device. If the cache mode is
+		 * explicitly set to writeback, automatically convert to
+		 * writethough mode.
+		 */
+		if (is_zoned_device(dev) &&
+		    BDEV_CACHE_MODE(&sb) == CACHE_MODE_WRITEBACK) {
+			printf("Zoned device %s detected: convert to writethrough mode.\n\n",
+				dev);
+			SET_BDEV_CACHE_MODE(&sb, CACHE_MODE_WRITETHROUGH);
+		}
+
 		if (data_offset != BDEV_DATA_START_DEFAULT) {
 			sb.version = BCACHE_SB_VERSION_BDEV_WITH_OFFSET;
 			sb.data_offset = data_offset;
-- 
2.26.2