Merge tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:
 "Smaller set of DM changes for this merge.  I've based these changes on
  Jens' for-4.4/reservations branch because the associated DM changes
  required it.

   - Revert a dm-multipath change that caused a regression for
     unprivledged users (e.g. kvm guests) that issued ioctls when a
     multipath device had no available paths.

   - Include Christoph's refactoring of DM's ioctl handling and add
     support for passing through persistent reservations with DM
     multipath.

   - All other changes are very simple cleanups"

* tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm switch: simplify conditional in alloc_region_table()
  dm delay: document that offsets are specified in sectors
  dm delay: capitalize the start of an delay_ctr() error message
  dm delay: Use DM_MAPIO macros instead of open-coded equivalents
  dm linear: remove redundant target name from error messages
  dm persistent data: eliminate unnecessary return values
  dm: eliminate unused "bioset" process for each bio-based DM device
  dm: convert ffs to __ffs
  dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()
  dm: add support for passing through persistent reservations
  dm: refactor ioctl handling
  Revert "dm mpath: fix stalls when handling invalid ioctls"
  dm: initialize non-blk-mq queue data before queue is used

10 files changed, 42 insertions, 68 deletions

diff --git a/drivers/md/persistent-data/dm-array.c b/drivers/md/persistent-data/dm-array.c
index e64b61ad0ef3..431a03067d64 100644
--- a/drivers/md/persistent-data/dm-array.c
+++ b/drivers/md/persistent-data/dm-array.c
@@ -233,9 +233,9 @@ static int get_ablock(struct dm_array_info *info, dm_block_t b,
 /*
  * Unlocks an array block.
  */
-static int unlock_ablock(struct dm_array_info *info, struct dm_block *block)
+static void unlock_ablock(struct dm_array_info *info, struct dm_block *block)
 {
-        return dm_tm_unlock(info->btree_info.tm, block);
+        dm_tm_unlock(info->btree_info.tm, block);
 }
 
 /*----------------------------------------------------------------*/
diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c
index 88dbe7b97c2c..f2393ba838eb 100644
--- a/drivers/md/persistent-data/dm-block-manager.c
+++ b/drivers/md/persistent-data/dm-block-manager.c
@@ -578,7 +578,7 @@ int dm_bm_write_lock_zero(struct dm_block_manager *bm,
 }
 EXPORT_SYMBOL_GPL(dm_bm_write_lock_zero);
 
-int dm_bm_unlock(struct dm_block *b)
+void dm_bm_unlock(struct dm_block *b)
 {
         struct buffer_aux *aux;
         aux = dm_bufio_get_aux_data(to_buffer(b));
@@ -590,8 +590,6 @@ int dm_bm_unlock(struct dm_block *b)
                 bl_up_read(&aux->lock);
 
         dm_bufio_release(to_buffer(b));
-
-        return 0;
 }
 EXPORT_SYMBOL_GPL(dm_bm_unlock);
 
diff --git a/drivers/md/persistent-data/dm-block-manager.h b/drivers/md/persistent-data/dm-block-manager.h
index 84330f59886d..3627d1b7667a 100644
--- a/drivers/md/persistent-data/dm-block-manager.h
+++ b/drivers/md/persistent-data/dm-block-manager.h
@@ -94,7 +94,7 @@ int dm_bm_write_lock_zero(struct dm_block_manager *bm, dm_block_t b,
                           struct dm_block_validator *v,
                           struct dm_block **result);
 
-int dm_bm_unlock(struct dm_block *b);
+void dm_bm_unlock(struct dm_block *b);
 
 /*
  * It's a common idiom to have a superblock that should be committed last.
diff --git a/drivers/md/persistent-data/dm-btree-internal.h b/drivers/md/persistent-data/dm-btree-internal.h
index 8731b6ea026b..a240990a7f33 100644
--- a/drivers/md/persistent-data/dm-btree-internal.h
+++ b/drivers/md/persistent-data/dm-btree-internal.h
@@ -52,7 +52,7 @@ void inc_children(struct dm_transaction_manager *tm, struct btree_node *n,
                   struct dm_btree_value_type *vt);
 
 int new_block(struct dm_btree_info *info, struct dm_block **result);
-int unlock_block(struct dm_btree_info *info, struct dm_block *b);
+void unlock_block(struct dm_btree_info *info, struct dm_block *b);
 
 /*
  * Spines keep track of the rolling locks.  There are 2 variants, read-only
diff --git a/drivers/md/persistent-data/dm-btree-remove.c b/drivers/md/persistent-data/dm-btree-remove.c
index 2e4c4cb79e4d..21ea537bd55e 100644
--- a/drivers/md/persistent-data/dm-btree-remove.c
+++ b/drivers/md/persistent-data/dm-btree-remove.c
@@ -165,9 +165,9 @@ static int init_child(struct dm_btree_info *info, struct dm_btree_value_type *vt
         return 0;
 }
 
-static int exit_child(struct dm_btree_info *info, struct child *c)
+static void exit_child(struct dm_btree_info *info, struct child *c)
 {
-        return dm_tm_unlock(info->tm, c->block);
+        dm_tm_unlock(info->tm, c->block);
 }
 
 static void shift(struct btree_node *left, struct btree_node *right, int count)
@@ -249,13 +249,10 @@ static int rebalance2(struct shadow_spine *s, struct dm_btree_info *info,
 
         __rebalance2(info, parent, &left, &right);
 
-        r = exit_child(info, &left);
-        if (r) {
-                exit_child(info, &right);
-                return r;
-        }
+        exit_child(info, &left);
+        exit_child(info, &right);
 
-        return exit_child(info, &right);
+        return 0;
 }
 
 /*
@@ -394,22 +391,9 @@ static int rebalance3(struct shadow_spine *s, struct dm_btree_info *info,
 
         __rebalance3(info, parent, &left, &center, &right);
 
-        r = exit_child(info, &left);
-        if (r) {
-                exit_child(info, &center);
-                exit_child(info, &right);
-                return r;
-        }
-
-        r = exit_child(info, &center);
-        if (r) {
-                exit_child(info, &right);
-                return r;
-        }
-
-        r = exit_child(info, &right);
-        if (r)
-                return r;
+        exit_child(info, &left);
+        exit_child(info, &center);
+        exit_child(info, &right);
 
         return 0;
 }
@@ -433,9 +417,7 @@ static int rebalance_children(struct shadow_spine *s,
 
                 memcpy(n, dm_block_data(child),
                        dm_bm_block_size(dm_tm_get_bm(info->tm)));
-                r = dm_tm_unlock(info->tm, child);
-                if (r)
-                        return r;
+                dm_tm_unlock(info->tm, child);
 
                 dm_tm_dec(info->tm, dm_block_location(child));
                 return 0;
diff --git a/drivers/md/persistent-data/dm-btree-spine.c b/drivers/md/persistent-data/dm-btree-spine.c
index 0dee514ba4c5..b27b8091a1ca 100644
--- a/drivers/md/persistent-data/dm-btree-spine.c
+++ b/drivers/md/persistent-data/dm-btree-spine.c
@@ -117,9 +117,9 @@ int new_block(struct dm_btree_info *info, struct dm_block **result)
         return dm_tm_new_block(info->tm, &btree_node_validator, result);
 }
 
-int unlock_block(struct dm_btree_info *info, struct dm_block *b)
+void unlock_block(struct dm_btree_info *info, struct dm_block *b)
 {
-        return dm_tm_unlock(info->tm, b);
+        dm_tm_unlock(info->tm, b);
 }
 
 /*----------------------------------------------------------------*/
@@ -137,9 +137,7 @@ int exit_ro_spine(struct ro_spine *s)
         int r = 0, i;
 
         for (i = 0; i < s->count; i++) {
-                int r2 = unlock_block(s->info, s->nodes[i]);
-                if (r2 < 0)
-                        r = r2;
+                unlock_block(s->info, s->nodes[i]);
         }
 
         return r;
@@ -150,9 +148,7 @@ int ro_step(struct ro_spine *s, dm_block_t new_child)
         int r;
 
         if (s->count == 2) {
-                r = unlock_block(s->info, s->nodes[0]);
-                if (r < 0)
-                        return r;
+                unlock_block(s->info, s->nodes[0]);
                 s->nodes[0] = s->nodes[1];
                 s->count--;
         }
@@ -194,9 +190,7 @@ int exit_shadow_spine(struct shadow_spine *s)
         int r = 0, i;
 
         for (i = 0; i < s->count; i++) {
-                int r2 = unlock_block(s->info, s->nodes[i]);
-                if (r2 < 0)
-                        r = r2;
+                unlock_block(s->info, s->nodes[i]);
         }
 
         return r;
@@ -208,9 +202,7 @@ int shadow_step(struct shadow_spine *s, dm_block_t b,
         int r;
 
         if (s->count == 2) {
-                r = unlock_block(s->info, s->nodes[0]);
-                if (r < 0)
-                        return r;
+                unlock_block(s->info, s->nodes[0]);
                 s->nodes[0] = s->nodes[1];
                 s->count--;
         }
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index 0e09aef43998..c573402033b2 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -141,7 +141,9 @@ int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root)
         n->header.value_size = cpu_to_le32(info->value_type.size);
 
         *root = dm_block_location(b);
-        return unlock_block(info, b);
+        unlock_block(info, b);
+
+        return 0;
 }
 EXPORT_SYMBOL_GPL(dm_btree_empty);
 
diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
index aacbe70c2c2e..306d2e4502c4 100644
--- a/drivers/md/persistent-data/dm-space-map-common.c
+++ b/drivers/md/persistent-data/dm-space-map-common.c
@@ -259,9 +259,7 @@ int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
 
                 idx.blocknr = cpu_to_le64(dm_block_location(b));
 
-                r = dm_tm_unlock(ll->tm, b);
-                if (r < 0)
-                        return r;
+                dm_tm_unlock(ll->tm, b);
 
                 idx.nr_free = cpu_to_le32(ll->entries_per_block);
                 idx.none_free_before = 0;
@@ -293,7 +291,9 @@ int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 
         *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
 
-        return dm_tm_unlock(ll->tm, blk);
+        dm_tm_unlock(ll->tm, blk);
+
+        return 0;
 }
 
 static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
@@ -373,9 +373,7 @@ int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
                         return r;
                 }
 
-                r = dm_tm_unlock(ll->tm, blk);
-                if (r < 0)
-                        return r;
+                dm_tm_unlock(ll->tm, blk);
 
                 *result = i * ll->entries_per_block + (dm_block_t) position;
                 return 0;
@@ -429,9 +427,7 @@ static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
         if (ref_count <= 2) {
                 sm_set_bitmap(bm_le, bit, ref_count);
 
-                r = dm_tm_unlock(ll->tm, nb);
-                if (r < 0)
-                        return r;
+                dm_tm_unlock(ll->tm, nb);
 
                 if (old > 2) {
                         r = dm_btree_remove(&ll->ref_count_info,
@@ -445,9 +441,7 @@ static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
                 __le32 le_rc = cpu_to_le32(ref_count);
 
                 sm_set_bitmap(bm_le, bit, 3);
-                r = dm_tm_unlock(ll->tm, nb);
-                if (r < 0)
-                        return r;
+                dm_tm_unlock(ll->tm, nb);
 
                 __dm_bless_for_disk(&le_rc);
                 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
@@ -556,7 +550,9 @@ static int metadata_ll_init_index(struct ll_disk *ll)
         memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
         ll->bitmap_root = dm_block_location(b);
 
-        return dm_tm_unlock(ll->tm, b);
+        dm_tm_unlock(ll->tm, b);
+
+        return 0;
 }
 
 static int metadata_ll_open(struct ll_disk *ll)
@@ -570,7 +566,9 @@ static int metadata_ll_open(struct ll_disk *ll)
                 return r;
 
         memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
-        return dm_tm_unlock(ll->tm, block);
+        dm_tm_unlock(ll->tm, block);
+
+        return 0;
 }
 
 static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
@@ -590,7 +588,9 @@ static int metadata_ll_commit(struct ll_disk *ll)
         memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
         ll->bitmap_root = dm_block_location(b);
 
-        return dm_tm_unlock(ll->tm, b);
+        dm_tm_unlock(ll->tm, b);
+
+        return 0;
 }
 
 int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
diff --git a/drivers/md/persistent-data/dm-transaction-manager.c b/drivers/md/persistent-data/dm-transaction-manager.c
index 9cb797d800cf..abe2c5dd0993 100644
--- a/drivers/md/persistent-data/dm-transaction-manager.c
+++ b/drivers/md/persistent-data/dm-transaction-manager.c
@@ -342,9 +342,9 @@ int dm_tm_read_lock(struct dm_transaction_manager *tm, dm_block_t b,
 }
 EXPORT_SYMBOL_GPL(dm_tm_read_lock);
 
-int dm_tm_unlock(struct dm_transaction_manager *tm, struct dm_block *b)
+void dm_tm_unlock(struct dm_transaction_manager *tm, struct dm_block *b)
 {
-        return dm_bm_unlock(b);
+        dm_bm_unlock(b);
 }
 EXPORT_SYMBOL_GPL(dm_tm_unlock);
 
diff --git a/drivers/md/persistent-data/dm-transaction-manager.h b/drivers/md/persistent-data/dm-transaction-manager.h
index 2e0d4d66fb1b..f3a18be68f30 100644
--- a/drivers/md/persistent-data/dm-transaction-manager.h
+++ b/drivers/md/persistent-data/dm-transaction-manager.h
@@ -94,7 +94,7 @@ int dm_tm_read_lock(struct dm_transaction_manager *tm, dm_block_t b,
                     struct dm_block_validator *v,
                     struct dm_block **result);
 
-int dm_tm_unlock(struct dm_transaction_manager *tm, struct dm_block *b);
+void dm_tm_unlock(struct dm_transaction_manager *tm, struct dm_block *b);
 
 /*
  * Functions for altering the reference count of a block directly.