summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorKent Overstreet <koverstreet@google.com>2013-04-11 15:14:35 -0700
committerKent Overstreet <koverstreet@google.com>2013-04-20 17:56:12 -0700
commit2903381fce71004a7ce24d40fad53ba8236a3921 (patch)
treef493d51bdf17b2376e3f79fe0aecc8a7a9e37263 /drivers
parentcef5279735d3f6f0243e626963e6d5c84efade0a (diff)
bcache: Take data offset from the bdev superblock.
Add a new superblock version, and consolidate related defines. Signed-off-by: Gabriel de Perthuis <g2p.code+bcache@gmail.com> Signed-off-by: Kent Overstreet <koverstreet@google.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/md/bcache/bcache.h47
-rw-r--r--drivers/md/bcache/request.c2
-rw-r--r--drivers/md/bcache/super.c108
3 files changed, 100 insertions, 57 deletions
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index f05723565f17..340146d7c17f 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -223,11 +223,17 @@ struct bkey {
#define BKEY_PADDED(key) \
union { struct bkey key; uint64_t key ## _pad[BKEY_PAD]; }
-/* Version 1: Backing device
+/* Version 0: Cache device
+ * Version 1: Backing device
* Version 2: Seed pointer into btree node checksum
- * Version 3: New UUID format
+ * Version 3: Cache device with new UUID format
+ * Version 4: Backing device with data offset
*/
-#define BCACHE_SB_VERSION 3
+#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 SB_SECTOR 8
#define SB_SIZE 4096
@@ -236,13 +242,12 @@ struct bkey {
/* SB_JOURNAL_BUCKETS must be divisible by BITS_PER_LONG */
#define MAX_CACHES_PER_SET 8
-#define BDEV_DATA_START 16 /* sectors */
+#define BDEV_DATA_START_DEFAULT 16 /* sectors */
struct cache_sb {
uint64_t csum;
uint64_t offset; /* sector where this sb was written */
uint64_t version;
-#define CACHE_BACKING_DEV 1
uint8_t magic[16];
@@ -257,12 +262,28 @@ struct cache_sb {
uint64_t seq;
uint64_t pad[8];
- uint64_t nbuckets; /* device size */
- uint16_t block_size; /* sectors */
- uint16_t bucket_size; /* sectors */
+ union {
+ struct {
+ /* Cache devices */
+ uint64_t nbuckets; /* device size */
+
+ uint16_t block_size; /* sectors */
+ uint16_t bucket_size; /* sectors */
- uint16_t nr_in_set;
- uint16_t nr_this_dev;
+ uint16_t nr_in_set;
+ uint16_t nr_this_dev;
+ };
+ struct {
+ /* Backing devices */
+ uint64_t data_offset;
+
+ /*
+ * block_size from the cache device section is still used by
+ * backing devices, so don't add anything here until we fix
+ * things to not need it for backing devices anymore
+ */
+ };
+ };
uint32_t last_mount; /* time_t */
@@ -861,6 +882,12 @@ static inline bool key_merging_disabled(struct cache_set *c)
#endif
}
+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;
+}
+
struct bbio {
unsigned submit_time_us;
union {
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 83731dc36f34..e5ff12e52d5b 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -1220,7 +1220,7 @@ static void cached_dev_make_request(struct request_queue *q, struct bio *bio)
part_stat_unlock();
bio->bi_bdev = dc->bdev;
- bio->bi_sector += BDEV_DATA_START;
+ bio->bi_sector += dc->sb.data_offset;
if (cached_dev_get(dc)) {
s = search_alloc(bio, d);
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 5fa3cd2d9ff0..f1e69f2fad37 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -110,15 +110,7 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
sb->flags = le64_to_cpu(s->flags);
sb->seq = le64_to_cpu(s->seq);
-
- sb->nbuckets = le64_to_cpu(s->nbuckets);
- sb->block_size = le16_to_cpu(s->block_size);
- sb->bucket_size = le16_to_cpu(s->bucket_size);
-
- sb->nr_in_set = le16_to_cpu(s->nr_in_set);
- sb->nr_this_dev = le16_to_cpu(s->nr_this_dev);
sb->last_mount = le32_to_cpu(s->last_mount);
-
sb->first_bucket = le16_to_cpu(s->first_bucket);
sb->keys = le16_to_cpu(s->keys);
@@ -147,53 +139,77 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
if (bch_is_zero(sb->uuid, 16))
goto err;
- err = "Unsupported superblock version";
- if (sb->version > BCACHE_SB_VERSION)
- goto err;
+ switch (sb->version) {
+ case BCACHE_SB_VERSION_BDEV:
+ sb->block_size = le16_to_cpu(s->block_size);
+ sb->data_offset = BDEV_DATA_START_DEFAULT;
+ break;
+ case BCACHE_SB_VERSION_BDEV_WITH_OFFSET:
+ sb->block_size = le16_to_cpu(s->block_size);
+ sb->data_offset = le64_to_cpu(s->data_offset);
+
+ err = "Bad data offset";
+ if (sb->data_offset < BDEV_DATA_START_DEFAULT)
+ goto err;
- err = "Bad block/bucket size";
- if (!is_power_of_2(sb->block_size) || sb->block_size > PAGE_SECTORS ||
- !is_power_of_2(sb->bucket_size) || sb->bucket_size < PAGE_SECTORS)
- goto err;
+ break;
+ case BCACHE_SB_VERSION_CDEV:
+ case BCACHE_SB_VERSION_CDEV_WITH_UUID:
+ sb->nbuckets = le64_to_cpu(s->nbuckets);
+ sb->block_size = le16_to_cpu(s->block_size);
+ sb->bucket_size = le16_to_cpu(s->bucket_size);
- err = "Too many buckets";
- if (sb->nbuckets > LONG_MAX)
- goto err;
+ sb->nr_in_set = le16_to_cpu(s->nr_in_set);
+ sb->nr_this_dev = le16_to_cpu(s->nr_this_dev);
- err = "Not enough buckets";
- if (sb->nbuckets < 1 << 7)
- goto err;
+ err = "Too many buckets";
+ if (sb->nbuckets > LONG_MAX)
+ goto err;
- err = "Invalid superblock: device too small";
- if (get_capacity(bdev->bd_disk) < sb->bucket_size * sb->nbuckets)
- goto err;
+ err = "Not enough buckets";
+ if (sb->nbuckets < 1 << 7)
+ goto err;
- if (sb->version == CACHE_BACKING_DEV)
- goto out;
+ err = "Bad block/bucket size";
+ if (!is_power_of_2(sb->block_size) ||
+ sb->block_size > PAGE_SECTORS ||
+ !is_power_of_2(sb->bucket_size) ||
+ sb->bucket_size < PAGE_SECTORS)
+ goto err;
- err = "Bad UUID";
- if (bch_is_zero(sb->set_uuid, 16))
- goto err;
+ err = "Invalid superblock: device too small";
+ if (get_capacity(bdev->bd_disk) < sb->bucket_size * sb->nbuckets)
+ goto err;
- err = "Bad cache device number in set";
- if (!sb->nr_in_set ||
- sb->nr_in_set <= sb->nr_this_dev ||
- sb->nr_in_set > MAX_CACHES_PER_SET)
- goto err;
+ err = "Bad UUID";
+ if (bch_is_zero(sb->set_uuid, 16))
+ goto err;
- err = "Journal buckets not sequential";
- for (i = 0; i < sb->keys; i++)
- if (sb->d[i] != sb->first_bucket + i)
+ err = "Bad cache device number in set";
+ if (!sb->nr_in_set ||
+ sb->nr_in_set <= sb->nr_this_dev ||
+ sb->nr_in_set > MAX_CACHES_PER_SET)
goto err;
- err = "Too many journal buckets";
- if (sb->first_bucket + sb->keys > sb->nbuckets)
- goto err;
+ err = "Journal buckets not sequential";
+ for (i = 0; i < sb->keys; i++)
+ if (sb->d[i] != sb->first_bucket + i)
+ goto err;
- err = "Invalid superblock: first bucket comes before end of super";
- if (sb->first_bucket * sb->bucket_size < 16)
+ err = "Too many journal buckets";
+ if (sb->first_bucket + sb->keys > sb->nbuckets)
+ goto err;
+
+ err = "Invalid superblock: first bucket comes before end of super";
+ if (sb->first_bucket * sb->bucket_size < 16)
+ goto err;
+
+ break;
+ default:
+ err = "Unsupported superblock version";
goto err;
-out:
+ }
+
sb->last_mount = get_seconds();
err = NULL;
@@ -286,7 +302,7 @@ void bcache_write_super(struct cache_set *c)
for_each_cache(ca, c, i) {
struct bio *bio = &ca->sb_bio;
- ca->sb.version = BCACHE_SB_VERSION;
+ ca->sb.version = BCACHE_SB_VERSION_CDEV_WITH_UUID;
ca->sb.seq = c->sb.seq;
ca->sb.last_mount = c->sb.last_mount;
@@ -1049,7 +1065,7 @@ static const char *register_bdev(struct cache_sb *sb, struct page *sb_page,
g = dc->disk.disk;
- set_capacity(g, dc->bdev->bd_part->nr_sects - 16);
+ set_capacity(g, dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
bch_cached_dev_request_init(dc);
@@ -1802,7 +1818,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
if (err)
goto err_close;
- if (sb->version == CACHE_BACKING_DEV) {
+ if (SB_IS_BDEV(sb)) {
struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
err = register_bdev(sb, sb_page, bdev, dc);