This patch upgrades super block versions for adding feature sets into
struct cache_sb_disk,
128 __u64 feature_compat;
129 __u64 feature_incompat;
130 __u64 feature_ro_compat;
With the feature set flags, it will be convenient to add new features
without upgrade super block version again (at least for a long time).
The new added versions are,
- BCACHE_SB_VERSION_CDEV_WITH_FEATURES for cache device super block
- BCACHE_SB_VERSION_BDEV_WITH_FEATURES for backing device super block
The feature set flags are also added into the in-memory super block
struct cache_sb. The feature sets conversion between cache_sb_disk and
cache_sb also added into to_cache_sb() and to_cache_sb_disk().
Some feature sets related macros are also added into bcache.h, and a new
file feature.c is added for future new features record and display.
Signed-off-by: Coly Li <colyli@xxxxxxx>
---
Makefile | 2 +-
bcache.h | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
features.c | 22 ++++++++++++++
lib.c | 12 ++++++++
4 files changed, 118 insertions(+), 3 deletions(-)
create mode 100644 features.c
diff --git a/Makefile b/Makefile
index b4546a1..8b87a67 100644
--- a/Makefile
+++ b/Makefile
@@ -38,4 +38,4 @@ bcache-register: bcache-register.o
bcache: CFLAGS += `pkg-config --cflags blkid uuid smartcols`
bcache: LDLIBS += `pkg-config --libs blkid uuid smartcols`
bcache: CFLAGS += -std=gnu99
-bcache: crc64.o lib.o make.o zoned.o
+bcache: crc64.o lib.o make.o zoned.o features.o
diff --git a/bcache.h b/bcache.h
index 250da9d..9d969e1 100644
--- a/bcache.h
+++ b/bcache.h
@@ -29,12 +29,16 @@ static const char bcache_magic[] = {
* Version 2: Seed pointer into btree node checksum
* Version 3: Cache device with new UUID format
* Version 4: Backing device with data offset
+ * Version 5: Cache adn backing devices with compat/incompat/ro_compat
+ * feature sets
*/
#define BCACHE_SB_VERSION_CDEV 0
#define BCACHE_SB_VERSION_BDEV 1
#define BCACHE_SB_VERSION_CDEV_WITH_UUID 3
#define BCACHE_SB_VERSION_BDEV_WITH_OFFSET 4
-#define BCACHE_SB_MAX_VERSION 4
+#define BCACHE_SB_VERSION_CDEV_WITH_FEATURES 5
+#define BCACHE_SB_VERSION_BDEV_WITH_FEATURES 6
+#define BCACHE_SB_MAX_VERSION 6
#define SB_SECTOR 8
#define SB_LABEL_SIZE 32
@@ -59,7 +63,11 @@ struct cache_sb_disk {
__le64 flags;
__le64 seq;
- __le64 pad[8];
+ __le64 feature_compat;
+ __le64 feature_incompat;
+ __le64 feature_ro_compat;
+
+ __le64 pad[5];
union {
struct {
@@ -116,6 +124,10 @@ struct cache_sb {
__u64 flags;
__u64 seq;
+ __u64 feature_compat;
+ __u64 feature_incompat;
+ __u64 feature_ro_compat;
+
union {
struct {
/* Cache devices */
@@ -180,4 +192,73 @@ uint64_t crc64(const void *data, size_t len);
#define csum_set(i) \
crc64(((void *) (i)) + 8, ((void *) end(i)) - (((void *) (i)) + 8))
+/* Feature set definition */
+
+#define BCH_FEATURE_COMPAT 0
+#define BCH_FEATURE_RO_COMPAT 1
+#define BCH_FEATURE_INCOMPAT 2
+#define BCH_FEATURE_TYPE_MASK 0x03
+
+#define BCH_FEATURE_COMPAT_SUUP 0
+#define BCH_FEATURE_INCOMPAT_SUUP 0
+#define BCH_FEATURE_RO_COMPAT_SUUP 0
+
+#define BCH_HAS_COMPAT_FEATURE(sb, mask) \
+ ((sb)->feature_compat & (mask))
+#define BCH_HAS_RO_COMPAT_FEATURE(sb, mask) \
+ ((sb)->feature_ro_compat & (mask))
+#define BCH_HAS_INCOMPAT_FEATURE(sb, mask) \
+ ((sb)->feature_incompat & (mask))
+
+#define BCH_FEATURE_COMPAT_FUNCS(name, flagname) \
+static inline int bch_has_feature_##name(struct cache_sb *sb) \
+{ \
+ return (((sb)->feature_compat & \
+ BCH##_FEATURE_COMPAT_##flagname) != 0); \
+} \
+static inline void bch_set_feature_##name(struct cache_sb *sb) \
+{ \
+ (sb)->feature_compat |= \
+ BCH##_FEATURE_COMPAT_##flagname; \
+} \
+static inline void bch_clear_feature_##name(struct cache_sb *sb) \
+{ \
+ (sb)->feature_compat &= \
+ ~BCH##_FEATURE_COMPAT_##flagname; \
+}
+
+#define BCH_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
+static inline int bch_has_feature_##name(struct cache_sb *sb) \
+{ \
+ return (((sb)->feature_ro_compat & \
+ BCH##_FEATURE_RO_COMPAT_##flagname) != 0); \
+} \
+static inline void bch_set_feature_##name(struct cache_sb *sb) \
+{ \
+ (sb)->feature_ro_compat |= \
+ BCH##_FEATURE_RO_COMPAT_##flagname; \
+} \
+static inline void bch_clear_feature_##name(struct cache_sb *sb) \
+{ \
+ (sb)->feature_ro_compat &= \
+ ~BCH##_FEATURE_RO_COMPAT_##flagname; \
+}
+
+#define BCH_FEATURE_INCOMPAT_FUNCS(name, flagname) \
+static inline int bch_has_feature_##name(struct cache_sb *sb) \
+{ \
+ return (((sb)->feature_incompat & \
+ BCH##_FEATURE_INCOMPAT_##flagname) != 0); \
+} \
+static inline void bch_set_feature_##name(struct cache_sb *sb) \
+{ \
+ (sb)->feature_incompat |= \
+ BCH##_FEATURE_INCOMPAT_##flagname; \
+} \
+static inline void bch_clear_feature_##name(struct cache_sb *sb) \
+{ \
+ (sb)->feature_incompat &= \
+ ~BCH##_FEATURE_INCOMPAT_##flagname; \
+}
+
#endif
diff --git a/features.c b/features.c
new file mode 100644
index 0000000..a1c9884
--- /dev/null
+++ b/features.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author: Coly Li <colyli@xxxxxxx>
+ *
+ * Inspired by e2fsprogs features compat/incompat/ro_compat
+ * related code.
+ */
+#include <stdbool.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+#include "bcache.h"
+
+struct feature {
+ int compat;
+ unsigned int mask;
+ const char *string;
+};
+
+static struct feature feature_list[] = {
+ {0, 0, 0 },
+};
diff --git a/lib.c b/lib.c
index 9a2fa26..dcf752c 100644
--- a/lib.c
+++ b/lib.c
@@ -730,6 +730,12 @@ struct cache_sb *to_cache_sb(struct cache_sb *sb,
sb->d[i]= le64_to_cpu(sb_disk->d[i]);
}
+ if (sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) {
+ sb->feature_compat = le64_to_cpu(sb_disk->feature_compat);
+ sb->feature_incompat = le64_to_cpu(sb_disk->feature_incompat);
+ sb->feature_ro_compat = le64_to_cpu(sb_disk->feature_ro_compat);
+ }
+
return sb;
}
@@ -772,5 +778,11 @@ struct cache_sb_disk *to_cache_sb_disk(struct cache_sb_disk *sb_disk,
sb_disk->d[i] = cpu_to_le64(sb->d[i]);
}
+ if (sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) {
+ sb_disk->feature_compat = cpu_to_le64(sb->feature_compat);
+ sb_disk->feature_incompat = cpu_to_le64(sb->feature_incompat);
+ sb_disk->feature_ro_compat = cpu_to_le64(sb->feature_ro_compat);
+ }
+
return sb_disk;
}
--
2.26.2
