Merge tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull dm update from Alasdair G Kergon:
 "Miscellaneous device-mapper fixes, cleanups and performance
  improvements.

  Of particular note:
   - Disable broken WRITE SAME support in all targets except linear and
     striped.  Use it when kcopyd is zeroing blocks.
   - Remove several mempools from targets by moving the data into the
     bio's new front_pad area(which dm calls 'per_bio_data').
   - Fix a race in thin provisioning if discards are misused.
   - Prevent userspace from interfering with the ioctl parameters and
     use kmalloc for the data buffer if it's small instead of vmalloc.
   - Throttle some annoying error messages when I/O fails."

* tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: (36 commits)
  dm stripe: add WRITE SAME support
  dm: remove map_info
  dm snapshot: do not use map_context
  dm thin: dont use map_context
  dm raid1: dont use map_context
  dm flakey: dont use map_context
  dm raid1: rename read_record to bio_record
  dm: move target request nr to dm_target_io
  dm snapshot: use per_bio_data
  dm verity: use per_bio_data
  dm raid1: use per_bio_data
  dm: introduce per_bio_data
  dm kcopyd: add WRITE SAME support to dm_kcopyd_zero
  dm linear: add WRITE SAME support
  dm: add WRITE SAME support
  dm: prepare to support WRITE SAME
  dm ioctl: use kmalloc if possible
  dm ioctl: remove PF_MEMALLOC
  dm persistent data: improve improve space map block alloc failure message
  dm thin: use DMERR_LIMIT for errors
  ...

7 files changed, 77 insertions, 70 deletions

diff --git a/drivers/md/persistent-data/dm-block-manager.c b/drivers/md/persistent-data/dm-block-manager.c
index a3ae09124a67..28c3ed072a79 100644
--- a/drivers/md/persistent-data/dm-block-manager.c
+++ b/drivers/md/persistent-data/dm-block-manager.c
@@ -428,15 +428,17 @@ static int dm_bm_validate_buffer(struct dm_block_manager *bm,
                 if (!v)
                         return 0;
                 r = v->check(v, (struct dm_block *) buf, dm_bufio_get_block_size(bm->bufio));
-                if (unlikely(r))
+                if (unlikely(r)) {
+                        DMERR_LIMIT("%s validator check failed for block %llu", v->name,
+                                    (unsigned long long) dm_bufio_get_block_number(buf));
                         return r;
+                }
                 aux->validator = v;
         } else {
                 if (unlikely(aux->validator != v)) {
-                        DMERR("validator mismatch (old=%s vs new=%s) for block %llu",
-                                aux->validator->name, v ? v->name : "NULL",
-                                (unsigned long long)
-                                        dm_bufio_get_block_number(buf));
+                        DMERR_LIMIT("validator mismatch (old=%s vs new=%s) for block %llu",
+                                    aux->validator->name, v ? v->name : "NULL",
+                                    (unsigned long long) dm_bufio_get_block_number(buf));
                         return -EINVAL;
                 }
         }
diff --git a/drivers/md/persistent-data/dm-btree-internal.h b/drivers/md/persistent-data/dm-btree-internal.h
index 5709bfeab1e8..accbb05f17b6 100644
--- a/drivers/md/persistent-data/dm-btree-internal.h
+++ b/drivers/md/persistent-data/dm-btree-internal.h
@@ -36,13 +36,13 @@ struct node_header {
         __le32 padding;
 } __packed;
 
-struct node {
+struct btree_node {
         struct node_header header;
         __le64 keys[0];
 } __packed;
 
 
-void inc_children(struct dm_transaction_manager *tm, struct node *n,
+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);
@@ -64,7 +64,7 @@ struct ro_spine {
 void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info);
 int exit_ro_spine(struct ro_spine *s);
 int ro_step(struct ro_spine *s, dm_block_t new_child);
-struct node *ro_node(struct ro_spine *s);
+struct btree_node *ro_node(struct ro_spine *s);
 
 struct shadow_spine {
         struct dm_btree_info *info;
@@ -98,17 +98,17 @@ int shadow_root(struct shadow_spine *s);
 /*
  * Some inlines.
  */
-static inline __le64 *key_ptr(struct node *n, uint32_t index)
+static inline __le64 *key_ptr(struct btree_node *n, uint32_t index)
 {
         return n->keys + index;
 }
 
-static inline void *value_base(struct node *n)
+static inline void *value_base(struct btree_node *n)
 {
         return &n->keys[le32_to_cpu(n->header.max_entries)];
 }
 
-static inline void *value_ptr(struct node *n, uint32_t index)
+static inline void *value_ptr(struct btree_node *n, uint32_t index)
 {
         uint32_t value_size = le32_to_cpu(n->header.value_size);
         return value_base(n) + (value_size * index);
@@ -117,7 +117,7 @@ static inline void *value_ptr(struct node *n, uint32_t index)
 /*
  * Assumes the values are suitably-aligned and converts to core format.
  */
-static inline uint64_t value64(struct node *n, uint32_t index)
+static inline uint64_t value64(struct btree_node *n, uint32_t index)
 {
         __le64 *values_le = value_base(n);
 
@@ -127,7 +127,7 @@ static inline uint64_t value64(struct node *n, uint32_t index)
 /*
  * Searching for a key within a single node.
  */
-int lower_bound(struct node *n, uint64_t key);
+int lower_bound(struct btree_node *n, uint64_t key);
 
 extern struct dm_block_validator btree_node_validator;
 
diff --git a/drivers/md/persistent-data/dm-btree-remove.c b/drivers/md/persistent-data/dm-btree-remove.c
index aa71e2359a07..c4f28133ef82 100644
--- a/drivers/md/persistent-data/dm-btree-remove.c
+++ b/drivers/md/persistent-data/dm-btree-remove.c
@@ -53,7 +53,7 @@
 /*
  * Some little utilities for moving node data around.
  */
-static void node_shift(struct node *n, int shift)
+static void node_shift(struct btree_node *n, int shift)
 {
         uint32_t nr_entries = le32_to_cpu(n->header.nr_entries);
         uint32_t value_size = le32_to_cpu(n->header.value_size);
@@ -79,7 +79,7 @@ static void node_shift(struct node *n, int shift)
         }
 }
 
-static void node_copy(struct node *left, struct node *right, int shift)
+static void node_copy(struct btree_node *left, struct btree_node *right, int shift)
 {
         uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
         uint32_t value_size = le32_to_cpu(left->header.value_size);
@@ -108,7 +108,7 @@ static void node_copy(struct node *left, struct node *right, int shift)
 /*
  * Delete a specific entry from a leaf node.
  */
-static void delete_at(struct node *n, unsigned index)
+static void delete_at(struct btree_node *n, unsigned index)
 {
         unsigned nr_entries = le32_to_cpu(n->header.nr_entries);
         unsigned nr_to_copy = nr_entries - (index + 1);
@@ -128,7 +128,7 @@ static void delete_at(struct node *n, unsigned index)
         n->header.nr_entries = cpu_to_le32(nr_entries - 1);
 }
 
-static unsigned merge_threshold(struct node *n)
+static unsigned merge_threshold(struct btree_node *n)
 {
         return le32_to_cpu(n->header.max_entries) / 3;
 }
@@ -136,7 +136,7 @@ static unsigned merge_threshold(struct node *n)
 struct child {
         unsigned index;
         struct dm_block *block;
-        struct node *n;
+        struct btree_node *n;
 };
 
 static struct dm_btree_value_type le64_type = {
@@ -147,7 +147,7 @@ static struct dm_btree_value_type le64_type = {
         .equal = NULL
 };
 
-static int init_child(struct dm_btree_info *info, struct node *parent,
+static int init_child(struct dm_btree_info *info, struct btree_node *parent,
                       unsigned index, struct child *result)
 {
         int r, inc;
@@ -177,7 +177,7 @@ static int exit_child(struct dm_btree_info *info, struct child *c)
         return dm_tm_unlock(info->tm, c->block);
 }
 
-static void shift(struct node *left, struct node *right, int count)
+static void shift(struct btree_node *left, struct btree_node *right, int count)
 {
         uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
         uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
@@ -203,11 +203,11 @@ static void shift(struct node *left, struct node *right, int count)
         right->header.nr_entries = cpu_to_le32(nr_right + count);
 }
 
-static void __rebalance2(struct dm_btree_info *info, struct node *parent,
+static void __rebalance2(struct dm_btree_info *info, struct btree_node *parent,
                          struct child *l, struct child *r)
 {
-        struct node *left = l->n;
-        struct node *right = r->n;
+        struct btree_node *left = l->n;
+        struct btree_node *right = r->n;
         uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
         uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
         unsigned threshold = 2 * merge_threshold(left) + 1;
@@ -239,7 +239,7 @@ static int rebalance2(struct shadow_spine *s, struct dm_btree_info *info,
                       unsigned left_index)
 {
         int r;
-        struct node *parent;
+        struct btree_node *parent;
         struct child left, right;
 
         parent = dm_block_data(shadow_current(s));
@@ -270,9 +270,9 @@ static int rebalance2(struct shadow_spine *s, struct dm_btree_info *info,
  * in right, then rebalance2.  This wastes some cpu, but I want something
  * simple atm.
  */
-static void delete_center_node(struct dm_btree_info *info, struct node *parent,
+static void delete_center_node(struct dm_btree_info *info, struct btree_node *parent,
                                struct child *l, struct child *c, struct child *r,
-                               struct node *left, struct node *center, struct node *right,
+                               struct btree_node *left, struct btree_node *center, struct btree_node *right,
                                uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
 {
         uint32_t max_entries = le32_to_cpu(left->header.max_entries);
@@ -301,9 +301,9 @@ static void delete_center_node(struct dm_btree_info *info, struct node *parent,
 /*
  * Redistributes entries among 3 sibling nodes.
  */
-static void redistribute3(struct dm_btree_info *info, struct node *parent,
+static void redistribute3(struct dm_btree_info *info, struct btree_node *parent,
                           struct child *l, struct child *c, struct child *r,
-                          struct node *left, struct node *center, struct node *right,
+                          struct btree_node *left, struct btree_node *center, struct btree_node *right,
                           uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
 {
         int s;
@@ -343,12 +343,12 @@ static void redistribute3(struct dm_btree_info *info, struct node *parent,
         *key_ptr(parent, r->index) = right->keys[0];
 }
 
-static void __rebalance3(struct dm_btree_info *info, struct node *parent,
+static void __rebalance3(struct dm_btree_info *info, struct btree_node *parent,
                          struct child *l, struct child *c, struct child *r)
 {
-        struct node *left = l->n;
-        struct node *center = c->n;
-        struct node *right = r->n;
+        struct btree_node *left = l->n;
+        struct btree_node *center = c->n;
+        struct btree_node *right = r->n;
 
         uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
         uint32_t nr_center = le32_to_cpu(center->header.nr_entries);
@@ -371,7 +371,7 @@ static int rebalance3(struct shadow_spine *s, struct dm_btree_info *info,
                       unsigned left_index)
 {
         int r;
-        struct node *parent = dm_block_data(shadow_current(s));
+        struct btree_node *parent = dm_block_data(shadow_current(s));
         struct child left, center, right;
 
         /*
@@ -421,7 +421,7 @@ static int get_nr_entries(struct dm_transaction_manager *tm,
 {
         int r;
         struct dm_block *block;
-        struct node *n;
+        struct btree_node *n;
 
         r = dm_tm_read_lock(tm, b, &btree_node_validator, &block);
         if (r)
@@ -438,7 +438,7 @@ static int rebalance_children(struct shadow_spine *s,
 {
         int i, r, has_left_sibling, has_right_sibling;
         uint32_t child_entries;
-        struct node *n;
+        struct btree_node *n;
 
         n = dm_block_data(shadow_current(s));
 
@@ -483,7 +483,7 @@ static int rebalance_children(struct shadow_spine *s,
         return r;
 }
 
-static int do_leaf(struct node *n, uint64_t key, unsigned *index)
+static int do_leaf(struct btree_node *n, uint64_t key, unsigned *index)
 {
         int i = lower_bound(n, key);
 
@@ -506,7 +506,7 @@ static int remove_raw(struct shadow_spine *s, struct dm_btree_info *info,
                       uint64_t key, unsigned *index)
 {
         int i = *index, r;
-        struct node *n;
+        struct btree_node *n;
 
         for (;;) {
                 r = shadow_step(s, root, vt);
@@ -556,7 +556,7 @@ int dm_btree_remove(struct dm_btree_info *info, dm_block_t root,
         unsigned level, last_level = info->levels - 1;
         int index = 0, r = 0;
         struct shadow_spine spine;
-        struct node *n;
+        struct btree_node *n;
 
         init_shadow_spine(&spine, info);
         for (level = 0; level < info->levels; level++) {
diff --git a/drivers/md/persistent-data/dm-btree-spine.c b/drivers/md/persistent-data/dm-btree-spine.c
index d9a7912ee8ee..f199a0c4ed04 100644
--- a/drivers/md/persistent-data/dm-btree-spine.c
+++ b/drivers/md/persistent-data/dm-btree-spine.c
@@ -23,7 +23,7 @@ static void node_prepare_for_write(struct dm_block_validator *v,
                                    struct dm_block *b,
                                    size_t block_size)
 {
-        struct node *n = dm_block_data(b);
+        struct btree_node *n = dm_block_data(b);
         struct node_header *h = &n->header;
 
         h->blocknr = cpu_to_le64(dm_block_location(b));
@@ -38,15 +38,15 @@ static int node_check(struct dm_block_validator *v,
                       struct dm_block *b,
                       size_t block_size)
 {
-        struct node *n = dm_block_data(b);
+        struct btree_node *n = dm_block_data(b);
         struct node_header *h = &n->header;
         size_t value_size;
         __le32 csum_disk;
         uint32_t flags;
 
         if (dm_block_location(b) != le64_to_cpu(h->blocknr)) {
-                DMERR("node_check failed blocknr %llu wanted %llu",
-                      le64_to_cpu(h->blocknr), dm_block_location(b));
+                DMERR_LIMIT("node_check failed: blocknr %llu != wanted %llu",
+                            le64_to_cpu(h->blocknr), dm_block_location(b));
                 return -ENOTBLK;
         }
 
@@ -54,8 +54,8 @@ static int node_check(struct dm_block_validator *v,
                                                block_size - sizeof(__le32),
                                                BTREE_CSUM_XOR));
         if (csum_disk != h->csum) {
-                DMERR("node_check failed csum %u wanted %u",
-                      le32_to_cpu(csum_disk), le32_to_cpu(h->csum));
+                DMERR_LIMIT("node_check failed: csum %u != wanted %u",
+                            le32_to_cpu(csum_disk), le32_to_cpu(h->csum));
                 return -EILSEQ;
         }
 
@@ -63,12 +63,12 @@ static int node_check(struct dm_block_validator *v,
 
         if (sizeof(struct node_header) +
             (sizeof(__le64) + value_size) * le32_to_cpu(h->max_entries) > block_size) {
-                DMERR("node_check failed: max_entries too large");
+                DMERR_LIMIT("node_check failed: max_entries too large");
                 return -EILSEQ;
         }
 
         if (le32_to_cpu(h->nr_entries) > le32_to_cpu(h->max_entries)) {
-                DMERR("node_check failed, too many entries");
+                DMERR_LIMIT("node_check failed: too many entries");
                 return -EILSEQ;
         }
 
@@ -77,7 +77,7 @@ static int node_check(struct dm_block_validator *v,
          */
         flags = le32_to_cpu(h->flags);
         if (!(flags & INTERNAL_NODE) && !(flags & LEAF_NODE)) {
-                DMERR("node_check failed, node is neither INTERNAL or LEAF");
+                DMERR_LIMIT("node_check failed: node is neither INTERNAL or LEAF");
                 return -EILSEQ;
         }
 
@@ -164,7 +164,7 @@ int ro_step(struct ro_spine *s, dm_block_t new_child)
         return r;
 }
 
-struct node *ro_node(struct ro_spine *s)
+struct btree_node *ro_node(struct ro_spine *s)
 {
         struct dm_block *block;
 
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index d12b2cc51f1a..4caf66918cdb 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -38,7 +38,7 @@ static void array_insert(void *base, size_t elt_size, unsigned nr_elts,
 /*----------------------------------------------------------------*/
 
 /* makes the assumption that no two keys are the same. */
-static int bsearch(struct node *n, uint64_t key, int want_hi)
+static int bsearch(struct btree_node *n, uint64_t key, int want_hi)
 {
         int lo = -1, hi = le32_to_cpu(n->header.nr_entries);
 
@@ -58,12 +58,12 @@ static int bsearch(struct node *n, uint64_t key, int want_hi)
         return want_hi ? hi : lo;
 }
 
-int lower_bound(struct node *n, uint64_t key)
+int lower_bound(struct btree_node *n, uint64_t key)
 {
         return bsearch(n, key, 0);
 }
 
-void inc_children(struct dm_transaction_manager *tm, struct node *n,
+void inc_children(struct dm_transaction_manager *tm, struct btree_node *n,
                   struct dm_btree_value_type *vt)
 {
         unsigned i;
@@ -77,7 +77,7 @@ void inc_children(struct dm_transaction_manager *tm, struct node *n,
                         vt->inc(vt->context, value_ptr(n, i));
 }
 
-static int insert_at(size_t value_size, struct node *node, unsigned index,
+static int insert_at(size_t value_size, struct btree_node *node, unsigned index,
                       uint64_t key, void *value)
                       __dm_written_to_disk(value)
 {
@@ -122,7 +122,7 @@ int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root)
 {
         int r;
         struct dm_block *b;
-        struct node *n;
+        struct btree_node *n;
         size_t block_size;
         uint32_t max_entries;
 
@@ -154,7 +154,7 @@ EXPORT_SYMBOL_GPL(dm_btree_empty);
 #define MAX_SPINE_DEPTH 64
 struct frame {
         struct dm_block *b;
-        struct node *n;
+        struct btree_node *n;
         unsigned level;
         unsigned nr_children;
         unsigned current_child;
@@ -230,6 +230,11 @@ static void pop_frame(struct del_stack *s)
         dm_tm_unlock(s->tm, f->b);
 }
 
+static bool is_internal_level(struct dm_btree_info *info, struct frame *f)
+{
+        return f->level < (info->levels - 1);
+}
+
 int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
 {
         int r;
@@ -241,7 +246,7 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
         s->tm = info->tm;
         s->top = -1;
 
-        r = push_frame(s, root, 1);
+        r = push_frame(s, root, 0);
         if (r)
                 goto out;
 
@@ -267,7 +272,7 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
                         if (r)
                                 goto out;
 
-                } else if (f->level != (info->levels - 1)) {
+                } else if (is_internal_level(info, f)) {
                         b = value64(f->n, f->current_child);
                         f->current_child++;
                         r = push_frame(s, b, f->level + 1);
@@ -295,7 +300,7 @@ EXPORT_SYMBOL_GPL(dm_btree_del);
 /*----------------------------------------------------------------*/
 
 static int btree_lookup_raw(struct ro_spine *s, dm_block_t block, uint64_t key,
-                            int (*search_fn)(struct node *, uint64_t),
+                            int (*search_fn)(struct btree_node *, uint64_t),
                             uint64_t *result_key, void *v, size_t value_size)
 {
         int i, r;
@@ -406,7 +411,7 @@ static int btree_split_sibling(struct shadow_spine *s, dm_block_t root,
         size_t size;
         unsigned nr_left, nr_right;
         struct dm_block *left, *right, *parent;
-        struct node *ln, *rn, *pn;
+        struct btree_node *ln, *rn, *pn;
         __le64 location;
 
         left = shadow_current(s);
@@ -491,7 +496,7 @@ static int btree_split_beneath(struct shadow_spine *s, uint64_t key)
         size_t size;
         unsigned nr_left, nr_right;
         struct dm_block *left, *right, *new_parent;
-        struct node *pn, *ln, *rn;
+        struct btree_node *pn, *ln, *rn;
         __le64 val;
 
         new_parent = shadow_current(s);
@@ -576,7 +581,7 @@ static int btree_insert_raw(struct shadow_spine *s, dm_block_t root,
                             uint64_t key, unsigned *index)
 {
         int r, i = *index, top = 1;
-        struct node *node;
+        struct btree_node *node;
 
         for (;;) {
                 r = shadow_step(s, root, vt);
@@ -643,7 +648,7 @@ static int insert(struct dm_btree_info *info, dm_block_t root,
         unsigned level, index = -1, last_level = info->levels - 1;
         dm_block_t block = root;
         struct shadow_spine spine;
-        struct node *n;
+        struct btree_node *n;
         struct dm_btree_value_type le64_type;
 
         le64_type.context = NULL;
diff --git a/drivers/md/persistent-data/dm-space-map-common.c b/drivers/md/persistent-data/dm-space-map-common.c
index f3a9af8cdec3..3e7a88d99eb0 100644
--- a/drivers/md/persistent-data/dm-space-map-common.c
+++ b/drivers/md/persistent-data/dm-space-map-common.c
@@ -39,8 +39,8 @@ static int index_check(struct dm_block_validator *v,
         __le32 csum_disk;
 
         if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
-                DMERR("index_check failed blocknr %llu wanted %llu",
-                      le64_to_cpu(mi_le->blocknr), dm_block_location(b));
+                DMERR_LIMIT("index_check failed: blocknr %llu != wanted %llu",
+                            le64_to_cpu(mi_le->blocknr), dm_block_location(b));
                 return -ENOTBLK;
         }
 
@@ -48,8 +48,8 @@ static int index_check(struct dm_block_validator *v,
                                                block_size - sizeof(__le32),
                                                INDEX_CSUM_XOR));
         if (csum_disk != mi_le->csum) {
-                DMERR("index_check failed csum %u wanted %u",
-                      le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
+                DMERR_LIMIT("index_check failed: csum %u != wanted %u",
+                            le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
                 return -EILSEQ;
         }
 
@@ -89,8 +89,8 @@ static int bitmap_check(struct dm_block_validator *v,
         __le32 csum_disk;
 
         if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
-                DMERR("bitmap check failed blocknr %llu wanted %llu",
-                      le64_to_cpu(disk_header->blocknr), dm_block_location(b));
+                DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
+                            le64_to_cpu(disk_header->blocknr), dm_block_location(b));
                 return -ENOTBLK;
         }
 
@@ -98,8 +98,8 @@ static int bitmap_check(struct dm_block_validator *v,
                                                block_size - sizeof(__le32),
                                                BITMAP_CSUM_XOR));
         if (csum_disk != disk_header->csum) {
-                DMERR("bitmap check failed csum %u wanted %u",
-                      le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
+                DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
+                            le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
                 return -EILSEQ;
         }
 
diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
index e89ae5e7a519..906cf3df71af 100644
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -337,7 +337,7 @@ static int sm_metadata_new_block(struct dm_space_map *sm, dm_block_t *b)
 {
         int r = sm_metadata_new_block_(sm, b);
         if (r)
-                DMERR("out of metadata space");
+                DMERR("unable to allocate new metadata block");
         return r;
 }