bcache: add read_super_common() to read major part of super block

Later patches will introduce feature set bits to on-disk super block and
increase super block version. Current code in read_super() which reads
common part of super block for version BCACHE_SB_VERSION_CDEV and version
BCACHE_SB_VERSION_CDEV_WITH_UUID will be shared with the new version.

Therefore this patch moves the reusable part into read_super_common(),
this preparation patch will make later patches more simplier and only
focus on new feature set bits.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Coly Li 2020-07-25 20:00:23 +08:00 committed by Jens Axboe
parent 7a14812679
commit 5b21403c7f

View file

@ -59,6 +59,67 @@ struct workqueue_struct *bch_journal_wq;
/* Superblock */
static const char *read_super_common(struct cache_sb *sb, struct block_device *bdev,
struct cache_sb_disk *s)
{
const char *err;
unsigned int i;
sb->nbuckets = le64_to_cpu(s->nbuckets);
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);
err = "Too many buckets";
if (sb->nbuckets > LONG_MAX)
goto err;
err = "Not enough buckets";
if (sb->nbuckets < 1 << 7)
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;
err = "Invalid superblock: device too small";
if (get_capacity(bdev->bd_disk) <
sb->bucket_size * sb->nbuckets)
goto err;
err = "Bad UUID";
if (bch_is_zero(sb->set_uuid, 16))
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 = "Journal buckets not sequential";
for (i = 0; i < sb->keys; i++)
if (sb->d[i] != sb->first_bucket + i)
goto err;
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;
err = NULL;
err:
return err;
}
static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
struct cache_sb_disk **res)
{
@ -133,55 +194,9 @@ static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
break;
case BCACHE_SB_VERSION_CDEV:
case BCACHE_SB_VERSION_CDEV_WITH_UUID:
sb->nbuckets = le64_to_cpu(s->nbuckets);
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);
err = "Too many buckets";
if (sb->nbuckets > LONG_MAX)
err = read_super_common(sb, bdev, s);
if (err)
goto err;
err = "Not enough buckets";
if (sb->nbuckets < 1 << 7)
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;
err = "Invalid superblock: device too small";
if (get_capacity(bdev->bd_disk) <
sb->bucket_size * sb->nbuckets)
goto err;
err = "Bad UUID";
if (bch_is_zero(sb->set_uuid, 16))
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 = "Journal buckets not sequential";
for (i = 0; i < sb->keys; i++)
if (sb->d[i] != sb->first_bucket + i)
goto err;
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";