dm cache metadata: add "metadata2" feature
If "metadata2" is provided as a table argument when creating/loading a
cache target a more compact metadata format, with separate dirty bits,
is used. "metadata2" improves speed of shutting down a cache target.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 897dc72..5813d2a 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -179,6 +179,7 @@ enum cache_io_mode {
struct cache_features {
enum cache_metadata_mode mode;
enum cache_io_mode io_mode;
+ unsigned metadata_version;
};
struct cache_stats {
@@ -2541,13 +2542,14 @@ static void init_features(struct cache_features *cf)
{
cf->mode = CM_WRITE;
cf->io_mode = CM_IO_WRITEBACK;
+ cf->metadata_version = 1;
}
static int parse_features(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
static struct dm_arg _args[] = {
- {0, 1, "Invalid number of cache feature arguments"},
+ {0, 2, "Invalid number of cache feature arguments"},
};
int r;
@@ -2573,6 +2575,9 @@ static int parse_features(struct cache_args *ca, struct dm_arg_set *as,
else if (!strcasecmp(arg, "passthrough"))
cf->io_mode = CM_IO_PASSTHROUGH;
+ else if (!strcasecmp(arg, "metadata2"))
+ cf->metadata_version = 2;
+
else {
*error = "Unrecognised cache feature requested";
return -EINVAL;
@@ -2827,7 +2832,8 @@ static int cache_create(struct cache_args *ca, struct cache **result)
cmd = dm_cache_metadata_open(cache->metadata_dev->bdev,
ca->block_size, may_format,
- dm_cache_policy_get_hint_size(cache->policy));
+ dm_cache_policy_get_hint_size(cache->policy),
+ ca->features.metadata_version);
if (IS_ERR(cmd)) {
*error = "Error creating metadata object";
r = PTR_ERR(cmd);
@@ -3172,21 +3178,16 @@ static int cache_end_io(struct dm_target *ti, struct bio *bio, int error)
static int write_dirty_bitset(struct cache *cache)
{
- unsigned i, r;
+ int r;
if (get_cache_mode(cache) >= CM_READ_ONLY)
return -EINVAL;
- for (i = 0; i < from_cblock(cache->cache_size); i++) {
- r = dm_cache_set_dirty(cache->cmd, to_cblock(i),
- is_dirty(cache, to_cblock(i)));
- if (r) {
- metadata_operation_failed(cache, "dm_cache_set_dirty", r);
- return r;
- }
- }
+ r = dm_cache_set_dirty_bits(cache->cmd, from_cblock(cache->cache_size), cache->dirty_bitset);
+ if (r)
+ metadata_operation_failed(cache, "dm_cache_set_dirty_bits", r);
- return 0;
+ return r;
}
static int write_discard_bitset(struct cache *cache)
@@ -3562,14 +3563,19 @@ static void cache_status(struct dm_target *ti, status_type_t type,
(unsigned) atomic_read(&cache->stats.promotion),
(unsigned long) atomic_read(&cache->nr_dirty));
+ if (cache->features.metadata_version == 2)
+ DMEMIT("2 metadata2 ");
+ else
+ DMEMIT("1 ");
+
if (writethrough_mode(&cache->features))
- DMEMIT("1 writethrough ");
+ DMEMIT("writethrough ");
else if (passthrough_mode(&cache->features))
- DMEMIT("1 passthrough ");
+ DMEMIT("passthrough ");
else if (writeback_mode(&cache->features))
- DMEMIT("1 writeback ");
+ DMEMIT("writeback ");
else {
DMERR("%s: internal error: unknown io mode: %d",
@@ -3817,7 +3823,7 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
static struct target_type cache_target = {
.name = "cache",
- .version = {1, 9, 0},
+ .version = {1, 10, 0},
.module = THIS_MODULE,
.ctr = cache_ctr,
.dtr = cache_dtr,