dm: adjust structure members to improve alignment

Eliminate most holes in DM data structures that were modified by
commit 6f1c819c21 ("dm: convert to bioset_init()/mempool_init()").
Also prevent structure members from unnecessarily spanning cache
lines.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

9 files changed, 79 insertions, 73 deletions

diff --git a/drivers/md/dm-bio-prison-v1.c b/drivers/md/dm-bio-prison-v1.c
index e794e3662fdd..b5389890bbc3 100644
--- a/drivers/md/dm-bio-prison-v1.c
+++ b/drivers/md/dm-bio-prison-v1.c
@@ -19,8 +19,8 @@
 
 struct dm_bio_prison {
         spinlock_t lock;
-        mempool_t cell_pool;
         struct rb_root cells;
+        mempool_t cell_pool;
 };
 
 static struct kmem_cache *_cell_cache;
diff --git a/drivers/md/dm-bio-prison-v2.c b/drivers/md/dm-bio-prison-v2.c
index f866bc97b032..b092cdc8e1ae 100644
--- a/drivers/md/dm-bio-prison-v2.c
+++ b/drivers/md/dm-bio-prison-v2.c
@@ -21,8 +21,8 @@ struct dm_bio_prison_v2 {
         struct workqueue_struct *wq;
 
         spinlock_t lock;
-        mempool_t cell_pool;
         struct rb_root cells;
+        mempool_t cell_pool;
 };
 
 static struct kmem_cache *_cell_cache;
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 001c71248246..ce14a3d1f609 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -371,7 +371,13 @@ struct cache_stats {
 
 struct cache {
         struct dm_target *ti;
-        struct dm_target_callbacks callbacks;
+        spinlock_t lock;
+
+        /*
+         * Fields for converting from sectors to blocks.
+         */
+        int sectors_per_block_shift;
+        sector_t sectors_per_block;
 
         struct dm_cache_metadata *cmd;
 
@@ -402,13 +408,11 @@ struct cache {
         dm_cblock_t cache_size;
 
         /*
-         * Fields for converting from sectors to blocks.
+         * Invalidation fields.
          */
-        sector_t sectors_per_block;
-        int sectors_per_block_shift;
+        spinlock_t invalidation_lock;
+        struct list_head invalidation_requests;
 
-        spinlock_t lock;
-        struct bio_list deferred_bios;
         sector_t migration_threshold;
         wait_queue_head_t migration_wait;
         atomic_t nr_allocated_migrations;
@@ -419,13 +423,11 @@ struct cache {
          */
         atomic_t nr_io_migrations;
 
+        struct bio_list deferred_bios;
+
         struct rw_semaphore quiesce_lock;
 
-        /*
-         * cache_size entries, dirty if set
-         */
-        atomic_t nr_dirty;
-        unsigned long *dirty_bitset;
+        struct dm_target_callbacks callbacks;
 
         /*
          * origin_blocks entries, discarded if set.
@@ -442,17 +444,27 @@ struct cache {
         const char **ctr_args;
 
         struct dm_kcopyd_client *copier;
-        struct workqueue_struct *wq;
         struct work_struct deferred_bio_worker;
         struct work_struct migration_worker;
+        struct workqueue_struct *wq;
         struct delayed_work waker;
         struct dm_bio_prison_v2 *prison;
-        struct bio_set bs;
 
-        mempool_t migration_pool;
+        /*
+         * cache_size entries, dirty if set
+         */
+        unsigned long *dirty_bitset;
+        atomic_t nr_dirty;
 
-        struct dm_cache_policy *policy;
         unsigned policy_nr_args;
+        struct dm_cache_policy *policy;
+
+        /*
+         * Cache features such as write-through.
+         */
+        struct cache_features features;
+
+        struct cache_stats stats;
 
         bool need_tick_bio:1;
         bool sized:1;
@@ -461,25 +473,16 @@ struct cache {
         bool loaded_mappings:1;
         bool loaded_discards:1;
 
-        /*
-         * Cache features such as write-through.
-         */
-        struct cache_features features;
-
-        struct cache_stats stats;
+        struct rw_semaphore background_work_lock;
 
-        /*
-         * Invalidation fields.
-         */
-        spinlock_t invalidation_lock;
-        struct list_head invalidation_requests;
+        struct batcher committer;
+        struct work_struct commit_ws;
 
         struct io_tracker tracker;
 
-        struct work_struct commit_ws;
-        struct batcher committer;
+        mempool_t migration_pool;
 
-        struct rw_semaphore background_work_lock;
+        struct bio_set bs;
 };
 
 struct per_bio_data {
diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h
index f21c5d21bf1b..7d480c930eaf 100644
--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -31,6 +31,9 @@ struct dm_kobject_holder {
 struct mapped_device {
         struct mutex suspend_lock;
 
+        struct mutex table_devices_lock;
+        struct list_head table_devices;
+
         /*
          * The current mapping (struct dm_table *).
          * Use dm_get_live_table{_fast} or take suspend_lock for
@@ -38,17 +41,14 @@ struct mapped_device {
          */
         void __rcu *map;
 
-        struct list_head table_devices;
-        struct mutex table_devices_lock;
-
         unsigned long flags;
 
-        struct request_queue *queue;
-        int numa_node_id;
-
-        enum dm_queue_mode type;
         /* Protect queue and type against concurrent access. */
         struct mutex type_lock;
+        enum dm_queue_mode type;
+
+        int numa_node_id;
+        struct request_queue *queue;
 
         atomic_t holders;
         atomic_t open_count;
@@ -56,21 +56,21 @@ struct mapped_device {
         struct dm_target *immutable_target;
         struct target_type *immutable_target_type;
 
+        char name[16];
         struct gendisk *disk;
         struct dax_device *dax_dev;
-        char name[16];
-
-        void *interface_ptr;
 
         /*
          * A list of ios that arrived while we were suspended.
          */
-        atomic_t pending[2];
-        wait_queue_head_t wait;
         struct work_struct work;
+        wait_queue_head_t wait;
+        atomic_t pending[2];
         spinlock_t deferred_lock;
         struct bio_list deferred;
 
+        void *interface_ptr;
+
         /*
          * Event handling.
          */
@@ -84,17 +84,17 @@ struct mapped_device {
         unsigned internal_suspend_count;
 
         /*
-         * Processing queue (flush)
-         */
-        struct workqueue_struct *wq;
-
-        /*
          * io objects are allocated from here.
          */
         struct bio_set io_bs;
         struct bio_set bs;
 
         /*
+         * Processing queue (flush)
+         */
+        struct workqueue_struct *wq;
+
+        /*
          * freeze/thaw support require holding onto a super block
          */
         struct super_block *frozen_sb;
@@ -102,11 +102,11 @@ struct mapped_device {
         /* forced geometry settings */
         struct hd_geometry geometry;
 
-        struct block_device *bdev;
-
         /* kobject and completion */
         struct dm_kobject_holder kobj_holder;
 
+        struct block_device *bdev;
+
         /* zero-length flush that will be cloned and submitted to targets */
         struct bio flush_bio;
 
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index da02f4d8e4b9..4939fbc34ff2 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -139,25 +139,13 @@ struct crypt_config {
         struct dm_dev *dev;
         sector_t start;
 
-        /*
-         * pool for per bio private data, crypto requests,
-         * encryption requeusts/buffer pages and integrity tags
-         */
-        mempool_t req_pool;
-        mempool_t page_pool;
-        mempool_t tag_pool;
-        unsigned tag_pool_max_sectors;
-
         struct percpu_counter n_allocated_pages;
 
-        struct bio_set bs;
-        struct mutex bio_alloc_lock;
-
         struct workqueue_struct *io_queue;
         struct workqueue_struct *crypt_queue;
 
-        struct task_struct *write_thread;
         wait_queue_head_t write_thread_wait;
+        struct task_struct *write_thread;
         struct rb_root write_tree;
 
         char *cipher;
@@ -213,6 +201,18 @@ struct crypt_config {
         unsigned int integrity_iv_size;
         unsigned int on_disk_tag_size;
 
+        /*
+         * pool for per bio private data, crypto requests,
+         * encryption requeusts/buffer pages and integrity tags
+         */
+        unsigned tag_pool_max_sectors;
+        mempool_t tag_pool;
+        mempool_t req_pool;
+        mempool_t page_pool;
+
+        struct bio_set bs;
+        struct mutex bio_alloc_lock;
+
         u8 *authenc_key; /* space for keys in authenc() format (if used) */
         u8 key[0];
 };
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index ce7efc7434be..3c7547a3c371 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -45,7 +45,6 @@ struct dm_kcopyd_client {
         struct dm_io_client *io_client;
 
         wait_queue_head_t destroyq;
-        atomic_t nr_jobs;
 
         mempool_t job_pool;
 
@@ -54,6 +53,8 @@ struct dm_kcopyd_client {
 
         struct dm_kcopyd_throttle *throttle;
 
+        atomic_t nr_jobs;
+
 /*
  * We maintain three lists of jobs:
  *
diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c
index abf3521b80a8..c832ec398f02 100644
--- a/drivers/md/dm-region-hash.c
+++ b/drivers/md/dm-region-hash.c
@@ -63,27 +63,28 @@ struct dm_region_hash {
 
         /* hash table */
         rwlock_t hash_lock;
-        mempool_t region_pool;
         unsigned mask;
         unsigned nr_buckets;
         unsigned prime;
         unsigned shift;
         struct list_head *buckets;
 
+        /*
+         * If there was a flush failure no regions can be marked clean.
+         */
+        int flush_failure;
+
         unsigned max_recovery; /* Max # of regions to recover in parallel */
 
         spinlock_t region_lock;
         atomic_t recovery_in_flight;
-        struct semaphore recovery_count;
         struct list_head clean_regions;
         struct list_head quiesced_regions;
         struct list_head recovered_regions;
         struct list_head failed_recovered_regions;
+        struct semaphore recovery_count;
 
-        /*
-         * If there was a flush failure no regions can be marked clean.
-         */
-        int flush_failure;
+        mempool_t region_pool;
 
         void *context;
         sector_t target_begin;
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 5772756c63c1..6cf9c9364103 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -240,9 +240,9 @@ struct pool {
         struct dm_bio_prison *prison;
         struct dm_kcopyd_client *copier;
 
+        struct work_struct worker;
         struct workqueue_struct *wq;
         struct throttle throttle;
-        struct work_struct worker;
         struct delayed_work waker;
         struct delayed_work no_space_timeout;
 
@@ -260,7 +260,6 @@ struct pool {
         struct dm_deferred_set *all_io_ds;
 
         struct dm_thin_new_mapping *next_mapping;
-        mempool_t mapping_pool;
 
         process_bio_fn process_bio;
         process_bio_fn process_discard;
@@ -273,6 +272,8 @@ struct pool {
         process_mapping_fn process_prepared_discard_pt2;
 
         struct dm_bio_prison_cell **cell_sort_array;
+
+        mempool_t mapping_pool;
 };
 
 static enum pool_mode get_pool_mode(struct pool *pool);
diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index 30602d15ad9a..3c0e45f4dcf5 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -52,9 +52,9 @@ struct dmz_target {
         struct dmz_reclaim      *reclaim;
 
         /* For chunk work */
-        struct mutex            chunk_lock;
         struct radix_tree_root  chunk_rxtree;
         struct workqueue_struct *chunk_wq;
+        struct mutex            chunk_lock;
 
         /* For cloned BIOs to zones */
         struct bio_set          bio_set;