#define MIGRATION_COUNT_WINDOW 10
/*
- * The block size of the device holding cache data must be >= 32KB
+ * The block size of the device holding cache data must be
+ * between 32KB and 1GB.
*/
#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (32 * 1024 >> SECTOR_SHIFT)
+#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
/*
* FIXME: the cache is read/write for the time being.
struct dm_target *ti;
struct dm_target_callbacks callbacks;
+ struct dm_cache_metadata *cmd;
+
/*
* Metadata is written to this device.
*/
*/
struct dm_dev *cache_dev;
- /*
- * Cache features such as write-through.
- */
- struct cache_features features;
-
/*
* Size of the origin device in _complete_ blocks and native sectors.
*/
uint32_t sectors_per_block;
int sectors_per_block_shift;
- struct dm_cache_metadata *cmd;
-
spinlock_t lock;
struct bio_list deferred_bios;
struct bio_list deferred_flush_bios;
struct list_head completed_migrations;
struct list_head need_commit_migrations;
sector_t migration_threshold;
- atomic_t nr_migrations;
wait_queue_head_t migration_wait;
+ atomic_t nr_migrations;
+
+ wait_queue_head_t quiescing_wait;
+ atomic_t quiescing;
+ atomic_t quiescing_ack;
/*
* cache_size entries, dirty if set
/*
* origin_blocks entries, discarded if set.
*/
- uint32_t discard_block_size; /* a power of 2 times sectors per block */
dm_dblock_t discard_nr_blocks;
unsigned long *discard_bitset;
+ uint32_t discard_block_size; /* a power of 2 times sectors per block */
+
+ /*
+ * Rather than reconstructing the table line for the status we just
+ * save it and regurgitate.
+ */
+ unsigned nr_ctr_args;
+ const char **ctr_args;
struct dm_kcopyd_client *copier;
struct workqueue_struct *wq;
bool need_tick_bio:1;
bool sized:1;
- bool quiescing:1;
bool commit_requested:1;
bool loaded_mappings:1;
bool loaded_discards:1;
- struct cache_stats stats;
-
/*
- * Rather than reconstructing the table line for the status we just
- * save it and regurgitate.
+ * Cache features such as write-through.
*/
- unsigned nr_ctr_args;
- const char **ctr_args;
+ struct cache_features features;
+
+ struct cache_stats stats;
};
struct per_bio_data {
static void remap_to_cache_dirty(struct cache *cache, struct bio *bio,
dm_oblock_t oblock, dm_cblock_t cblock)
{
+ check_if_tick_bio_needed(cache, bio);
remap_to_cache(cache, bio, cblock);
if (bio_data_dir(bio) == WRITE) {
set_dirty(cache, oblock, cblock);
static void cleanup_migration(struct dm_cache_migration *mg)
{
- dec_nr_migrations(mg->cache);
+ struct cache *cache = mg->cache;
free_migration(mg);
+ dec_nr_migrations(cache);
}
static void migration_failure(struct dm_cache_migration *mg)
DMWARN_LIMIT("demotion failed; couldn't copy block");
policy_force_mapping(cache->policy, mg->new_oblock, mg->old_oblock);
- cell_defer(cache, mg->old_ocell, mg->promote ? 0 : 1);
+ cell_defer(cache, mg->old_ocell, mg->promote ? false : true);
if (mg->promote)
- cell_defer(cache, mg->new_ocell, 1);
+ cell_defer(cache, mg->new_ocell, true);
} else {
DMWARN_LIMIT("promotion failed; couldn't copy block");
policy_remove_mapping(cache->policy, mg->new_oblock);
- cell_defer(cache, mg->new_ocell, 1);
+ cell_defer(cache, mg->new_ocell, true);
}
cleanup_migration(mg);
return;
} else if (mg->demote) {
- cell_defer(cache, mg->old_ocell, mg->promote ? 0 : 1);
+ cell_defer(cache, mg->old_ocell, mg->promote ? false : true);
if (mg->promote) {
mg->demote = false;
/*----------------------------------------------------------------
* Main worker loop
*--------------------------------------------------------------*/
-static void start_quiescing(struct cache *cache)
+static bool is_quiescing(struct cache *cache)
{
- unsigned long flags;
-
- spin_lock_irqsave(&cache->lock, flags);
- cache->quiescing = 1;
- spin_unlock_irqrestore(&cache->lock, flags);
+ return atomic_read(&cache->quiescing);
}
-static void stop_quiescing(struct cache *cache)
+static void ack_quiescing(struct cache *cache)
{
- unsigned long flags;
-
- spin_lock_irqsave(&cache->lock, flags);
- cache->quiescing = 0;
- spin_unlock_irqrestore(&cache->lock, flags);
+ if (is_quiescing(cache)) {
+ atomic_inc(&cache->quiescing_ack);
+ wake_up(&cache->quiescing_wait);
+ }
}
-static bool is_quiescing(struct cache *cache)
+static void wait_for_quiescing_ack(struct cache *cache)
{
- int r;
- unsigned long flags;
+ wait_event(cache->quiescing_wait, atomic_read(&cache->quiescing_ack));
+}
- spin_lock_irqsave(&cache->lock, flags);
- r = cache->quiescing;
- spin_unlock_irqrestore(&cache->lock, flags);
+static void start_quiescing(struct cache *cache)
+{
+ atomic_inc(&cache->quiescing);
+ wait_for_quiescing_ack(cache);
+}
- return r;
+static void stop_quiescing(struct cache *cache)
+{
+ atomic_set(&cache->quiescing, 0);
+ atomic_set(&cache->quiescing_ack, 0);
}
static void wait_for_migrations(struct cache *cache)
struct cache *cache = container_of(ws, struct cache, worker);
do {
- if (!is_quiescing(cache))
+ if (!is_quiescing(cache)) {
+ writeback_some_dirty_blocks(cache);
+ process_deferred_writethrough_bios(cache);
process_deferred_bios(cache);
+ }
process_migrations(cache, &cache->quiesced_migrations, issue_copy);
process_migrations(cache, &cache->completed_migrations, complete_migration);
- writeback_some_dirty_blocks(cache);
-
- process_deferred_writethrough_bios(cache);
-
if (commit_if_needed(cache)) {
process_deferred_flush_bios(cache, false);
process_migrations(cache, &cache->need_commit_migrations,
migration_success_post_commit);
}
+
+ ack_quiescing(cache);
+
} while (more_work(cache));
}
static int parse_block_size(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
- unsigned long tmp;
+ unsigned long block_size;
if (!at_least_one_arg(as, error))
return -EINVAL;
- if (kstrtoul(dm_shift_arg(as), 10, &tmp) || !tmp ||
- tmp < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
- tmp & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
+ if (kstrtoul(dm_shift_arg(as), 10, &block_size) || !block_size ||
+ block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
+ block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
+ block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
*error = "Invalid data block size";
return -EINVAL;
}
- if (tmp > ca->cache_sectors) {
+ if (block_size > ca->cache_sectors) {
*error = "Data block size is larger than the cache device";
return -EINVAL;
}
- ca->block_size = tmp;
+ ca->block_size = block_size;
return 0;
}
static int create_cache_policy(struct cache *cache, struct cache_args *ca,
char **error)
{
- cache->policy = dm_cache_policy_create(ca->policy_name,
- cache->cache_size,
- cache->origin_sectors,
- cache->sectors_per_block);
- if (!cache->policy) {
+ struct dm_cache_policy *p = dm_cache_policy_create(ca->policy_name,
+ cache->cache_size,
+ cache->origin_sectors,
+ cache->sectors_per_block);
+ if (IS_ERR(p)) {
*error = "Error creating cache's policy";
- return -ENOMEM;
+ return PTR_ERR(p);
}
+ cache->policy = p;
return 0;
}
atomic_set(&cache->nr_migrations, 0);
init_waitqueue_head(&cache->migration_wait);
+ init_waitqueue_head(&cache->quiescing_wait);
+ atomic_set(&cache->quiescing, 0);
+ atomic_set(&cache->quiescing_ack, 0);
+
r = -ENOMEM;
cache->nr_dirty = 0;
cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size));
cache->need_tick_bio = true;
cache->sized = false;
- cache->quiescing = false;
cache->commit_requested = false;
cache->loaded_mappings = false;
cache->loaded_discards = false;
static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct cache *cache = ti->private;
+ uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
- blk_limits_io_min(limits, 0);
- blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT);
+ /*
+ * If the system-determined stacked limits are compatible with the
+ * cache's blocksize (io_opt is a factor) do not override them.
+ */
+ if (io_opt_sectors < cache->sectors_per_block ||
+ do_div(io_opt_sectors, cache->sectors_per_block)) {
+ blk_limits_io_min(limits, 0);
+ blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT);
+ }
set_discard_limits(cache, limits);
}
projects / cascardo / linux.git / blobdiff