diff --git a/drivers/md/bcache/features.h b/drivers/md/bcache/features.h
new file mode 100644
index 0000000000000000000000000000000000000000..ae7df37b98625caf302203c41bf0fe891fdd6796
--- /dev/null
+++ b/drivers/md/bcache/features.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _BCACHE_FEATURES_H
+#define _BCACHE_FEATURES_H
+
+#include <linux/bcache.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+#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_RO_COMPAT_SUUP 0
+#define BCH_FEATURE_INCOMPAT_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))
+
+/* Feature set definition */
+
+#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/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 40fb18028c0184624ffebbde4c8834c6980f72d7..c6ef410a21a88e68d1c320821e1315596fc2df29 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -13,6 +13,7 @@
#include "extents.h"
#include "request.h"
#include "writeback.h"
+#include "features.h"
#include <linux/blkdev.h>
#include <linux/debugfs.h>
@@ -194,6 +195,7 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
sb->data_offset = BDEV_DATA_START_DEFAULT;
break;
case BCACHE_SB_VERSION_BDEV_WITH_OFFSET:
+ case BCACHE_SB_VERSION_BDEV_WITH_FEATURES:
sb->data_offset = le64_to_cpu(s->data_offset);
err = "Bad data offset";
@@ -207,6 +209,14 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
if (err)
goto err;
break;
+ case BCACHE_SB_VERSION_CDEV_WITH_FEATURES:
+ err = read_super_common(sb, bdev, s);
+ if (err)
+ goto err;
+ sb->feature_compat = le64_to_cpu(s->feature_compat);
+ sb->feature_incompat = le64_to_cpu(s->feature_incompat);
+ sb->feature_ro_compat = le64_to_cpu(s->feature_ro_compat);
+ break;
default:
err = "Unsupported superblock version";
goto err;
@@ -241,7 +251,6 @@ static void __write_super(struct cache_sb *sb, struct cache_sb_disk *out,
offset_in_page(out));
out->offset = cpu_to_le64(sb->offset);
- out->version = cpu_to_le64(sb->version);
memcpy(out->uuid, sb->uuid, 16);
memcpy(out->set_uuid, sb->set_uuid, 16);
@@ -257,6 +266,13 @@ static void __write_super(struct cache_sb *sb, struct cache_sb_disk *out,
for (i = 0; i < sb->keys; i++)
out->d[i] = cpu_to_le64(sb->d[i]);
+ if (sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) {
+ out->feature_compat = cpu_to_le64(sb->feature_compat);
+ out->feature_incompat = cpu_to_le64(sb->feature_incompat);
+ out->feature_ro_compat = cpu_to_le64(sb->feature_ro_compat);
+ }
+
+ out->version = cpu_to_le64(sb->version);
out->csum = csum_set(out);
pr_debug("ver %llu, flags %llu, seq %llu\n",
@@ -313,17 +329,20 @@ void bcache_write_super(struct cache_set *c)
{
struct closure *cl = &c->sb_write;
struct cache *ca;
- unsigned int i;
+ unsigned int i, version = BCACHE_SB_VERSION_CDEV_WITH_UUID;
down(&c->sb_write_mutex);
closure_init(cl, &c->cl);
c->sb.seq++;
+ if (c->sb.version > version)
+ version = c->sb.version;
+
for_each_cache(ca, c, i) {
struct bio *bio = &ca->sb_bio;
- ca->sb.version = BCACHE_SB_VERSION_CDEV_WITH_UUID;
+ ca->sb.version = version;
ca->sb.seq = c->sb.seq;
ca->sb.last_mount = c->sb.last_mount;
@@ -1839,6 +1858,13 @@ struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
c->sb.bucket_size = sb->bucket_size;
c->sb.nr_in_set = sb->nr_in_set;
c->sb.last_mount = sb->last_mount;
+ c->sb.version = sb->version;
+ if (c->sb.version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) {
+ c->sb.feature_compat = sb->feature_compat;
+ c->sb.feature_ro_compat = sb->feature_ro_compat;
+ c->sb.feature_incompat = sb->feature_incompat;
+ }
+
c->bucket_bits = ilog2(sb->bucket_size);
c->block_bits = ilog2(sb->block_size);
c->nr_uuids = bucket_bytes(c) / sizeof(struct uuid_entry);
diff --git a/include/uapi/linux/bcache.h b/include/uapi/linux/bcache.h
index 9a1965c6c3d0d3b9bee6094c81505520fe9c635b..47df2db2e727653b281101e143b31031ac1f89eb 100644
--- a/include/uapi/linux/bcache.h
+++ b/include/uapi/linux/bcache.h
@@ -141,11 +141,13 @@ static inline struct bkey *bkey_idx(const struct bkey *k, unsigned int nr_keys)
* Version 3: Cache device with new UUID format
* Version 4: Backing device with data offset
*/
-#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 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_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_OFFSET (SB_SECTOR << SECTOR_SHIFT)
@@ -173,7 +175,12 @@ 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 {
@@ -224,7 +231,12 @@ struct cache_sb {
__u64 flags;
__u64 seq;
- __u64 pad[8];
+
+ __u64 feature_compat;
+ __u64 feature_incompat;
+ __u64 feature_ro_compat;
+
+ __u64 pad[5];
union {
struct {
@@ -262,7 +274,8 @@ struct cache_sb {
static inline _Bool SB_IS_BDEV(const struct cache_sb *sb)
{
return sb->version == BCACHE_SB_VERSION_BDEV
- || sb->version == BCACHE_SB_VERSION_BDEV_WITH_OFFSET;
+ || sb->version == BCACHE_SB_VERSION_BDEV_WITH_OFFSET
+ || sb->version == BCACHE_SB_VERSION_BDEV_WITH_FEATURES;
}
BITMASK(CACHE_SYNC, struct cache_sb, flags, 0, 1);