From 315ab92e58e3984351df8650527986b2b950e189 Mon Sep 17 00:00:00 2001
From: Gabriel <g2p.code@gmail.com>
Date: Wed, 1 May 2013 19:15:18 +0200
Subject: [PATCH] super-show: print cache mode (writethrough, writeback,
 writearound, none)

---
 bcache-super-show.c | 45 ++++++++++++++++++++++++++++++++-------------
 bcache.h            | 19 ++++++++++++++++---
 make-bcache.c       |  3 ++-
 3 files changed, 50 insertions(+), 17 deletions(-)

diff --git a/bcache-super-show.c b/bcache-super-show.c
index 95e54d4f..1607a677 100644
--- a/bcache-super-show.c
+++ b/bcache-super-show.c
@@ -137,20 +137,39 @@ int main(int argc, char **argv)
 		       sb.bucket_size * sb.nbuckets,
 		       CACHE_DISCARD(&sb) ? "yes" : "no",
 		       sb.nr_this_dev);
-	} else if (sb.version == BCACHE_SB_VERSION_BDEV) {
-		printf("dev.data.first_sector\t%u\n"
-		       "dev.data.writeback\t%s\n",
-		       BDEV_DATA_START_DEFAULT,
-		       BDEV_WRITEBACK(&sb) ? "yes" : "no");
-	} else if (sb.version == BCACHE_SB_VERSION_BDEV_WITH_OFFSET) {
-		if (sb.keys == 1 || sb.d[0]) {
-			fprintf(stderr, "Possible experimental format detected, bailing\n");
-			exit(3);
+	} else {
+		uint64_t first_sector;
+		if (sb.version == BCACHE_SB_VERSION_BDEV) {
+			first_sector = BDEV_DATA_START_DEFAULT;
+		} else {
+			if (sb.keys == 1 || sb.d[0]) {
+				fprintf(stderr,
+					"Possible experimental format detected, bailing\n");
+				exit(3);
+			}
+			first_sector = sb.data_offset;
+		}
+		printf("dev.data.first_sector\t%ju\n"
+		       "dev.data.cache_mode\t%ju",
+		       first_sector,
+		       BDEV_CACHE_MODE(&sb));
+
+		switch (BDEV_CACHE_MODE(&sb)) {
+			case CACHE_MODE_WRITETHROUGH:
+				printf(" [writethrough]\n");
+				break;
+			case CACHE_MODE_WRITEBACK:
+				printf(" [writeback]\n");
+				break;
+			case CACHE_MODE_WRITEAROUND:
+				printf(" [writearound]\n");
+				break;
+			case CACHE_MODE_NONE:
+				printf(" [no caching]\n");
+				break;
+			default:
+				putchar('\n');
 		}
-		printf("dev.data.first_sector\t%lu\n"
-		       "dev.data.writeback\t%s\n",
-		       sb.data_offset,
-		       BDEV_WRITEBACK(&sb) ? "yes" : "no");
 	}
 	putchar('\n');
 
diff --git a/bcache.h b/bcache.h
index bd871210..ac1633cd 100644
--- a/bcache.h
+++ b/bcache.h
@@ -91,10 +91,23 @@ static inline bool SB_IS_BDEV(const struct cache_sb *sb)
 		|| sb->version == BCACHE_SB_VERSION_BDEV_WITH_OFFSET;
 }
 
-BITMASK(BDEV_WRITEBACK,	struct cache_sb, flags, 0, 1);
+BITMASK(CACHE_SYNC,		struct cache_sb, flags, 0, 1);
+BITMASK(CACHE_DISCARD,		struct cache_sb, flags, 1, 1);
+BITMASK(CACHE_REPLACEMENT,	struct cache_sb, flags, 2, 3);
+#define CACHE_REPLACEMENT_LRU	0U
+#define CACHE_REPLACEMENT_FIFO	1U
+#define CACHE_REPLACEMENT_RANDOM 2U
 
-BITMASK(CACHE_DISCARD,	struct cache_sb, flags, 1, 1);
-BITMASK(CACHE_REPLACEMENT, struct cache_sb, flags, 2, 3);
+BITMASK(BDEV_CACHE_MODE,	struct cache_sb, flags, 0, 4);
+#define CACHE_MODE_WRITETHROUGH	0U
+#define CACHE_MODE_WRITEBACK	1U
+#define CACHE_MODE_WRITEAROUND	2U
+#define CACHE_MODE_NONE		3U
+BITMASK(BDEV_STATE,		struct cache_sb, flags, 61, 2);
+#define BDEV_STATE_NONE		0U
+#define BDEV_STATE_CLEAN	1U
+#define BDEV_STATE_DIRTY	2U
+#define BDEV_STATE_STALE	3U
 
 inline uint64_t crc64(const void *_data, size_t len);
 
diff --git a/make-bcache.c b/make-bcache.c
index 0a47c0ce..2a5124be 100644
--- a/make-bcache.c
+++ b/make-bcache.c
@@ -192,7 +192,8 @@ static void write_sb(char *dev, unsigned block_size, unsigned bucket_size,
 	uuid_unparse(sb.set_uuid, set_uuid_str);
 
 	if (SB_IS_BDEV(&sb)) {
-		SET_BDEV_WRITEBACK(&sb, writeback);
+		SET_BDEV_CACHE_MODE(
+			&sb, writeback ? CACHE_MODE_WRITEBACK : CACHE_MODE_WRITETHROUGH);
 
 		if (data_offset != BDEV_DATA_START_DEFAULT) {
 			sb.version = BCACHE_SB_VERSION_BDEV_WITH_OFFSET;