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authorJoe Thornber <ejt@redhat.com>2016-09-15 08:45:44 -0400
committerMike Snitzer <snitzer@redhat.com>2016-09-22 11:12:23 -0400
commitdd6a77d99859ab963503e67372ed278fe8ceab26 (patch)
tree8cf6068e462644ecb1cbbd91c5abf3fd570fa887 /drivers/md
parentb88efd43f900d608560211a18a38d450f8192948 (diff)
downloadlinux-dd6a77d99859ab963503e67372ed278fe8ceab26.tar.bz2
dm array: add dm_array_new()
dm_array_new() creates a new, populated array more efficiently than starting with an empty one and resizing. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/persistent-data/dm-array.c142
-rw-r--r--drivers/md/persistent-data/dm-array.h19
2 files changed, 130 insertions, 31 deletions
diff --git a/drivers/md/persistent-data/dm-array.c b/drivers/md/persistent-data/dm-array.c
index 431a03067d64..155180954cdf 100644
--- a/drivers/md/persistent-data/dm-array.c
+++ b/drivers/md/persistent-data/dm-array.c
@@ -277,6 +277,48 @@ static int insert_ablock(struct dm_array_info *info, uint64_t index,
return dm_btree_insert(&info->btree_info, *root, &index, &block_le, root);
}
+/*----------------------------------------------------------------*/
+
+static int __shadow_ablock(struct dm_array_info *info, dm_block_t b,
+ struct dm_block **block, struct array_block **ab)
+{
+ int inc;
+ int r = dm_tm_shadow_block(info->btree_info.tm, b,
+ &array_validator, block, &inc);
+ if (r)
+ return r;
+
+ *ab = dm_block_data(*block);
+ if (inc)
+ inc_ablock_entries(info, *ab);
+
+ return 0;
+}
+
+/*
+ * The shadow op will often be a noop. Only insert if it really
+ * copied data.
+ */
+static int __reinsert_ablock(struct dm_array_info *info, unsigned index,
+ struct dm_block *block, dm_block_t b,
+ dm_block_t *root)
+{
+ int r = 0;
+
+ if (dm_block_location(block) != b) {
+ /*
+ * dm_tm_shadow_block will have already decremented the old
+ * block, but it is still referenced by the btree. We
+ * increment to stop the insert decrementing it below zero
+ * when overwriting the old value.
+ */
+ dm_tm_inc(info->btree_info.tm, b);
+ r = insert_ablock(info, index, block, root);
+ }
+
+ return r;
+}
+
/*
* Looks up an array block in the btree. Then shadows it, and updates the
* btree to point to this new shadow. 'root' is an input/output parameter
@@ -286,49 +328,21 @@ static int shadow_ablock(struct dm_array_info *info, dm_block_t *root,
unsigned index, struct dm_block **block,
struct array_block **ab)
{
- int r, inc;
+ int r;
uint64_t key = index;
dm_block_t b;
__le64 block_le;
- /*
- * lookup
- */
r = dm_btree_lookup(&info->btree_info, *root, &key, &block_le);
if (r)
return r;
b = le64_to_cpu(block_le);
- /*
- * shadow
- */
- r = dm_tm_shadow_block(info->btree_info.tm, b,
- &array_validator, block, &inc);
+ r = __shadow_ablock(info, b, block, ab);
if (r)
return r;
- *ab = dm_block_data(*block);
- if (inc)
- inc_ablock_entries(info, *ab);
-
- /*
- * Reinsert.
- *
- * The shadow op will often be a noop. Only insert if it really
- * copied data.
- */
- if (dm_block_location(*block) != b) {
- /*
- * dm_tm_shadow_block will have already decremented the old
- * block, but it is still referenced by the btree. We
- * increment to stop the insert decrementing it below zero
- * when overwriting the old value.
- */
- dm_tm_inc(info->btree_info.tm, b);
- r = insert_ablock(info, index, *block, root);
- }
-
- return r;
+ return __reinsert_ablock(info, index, *block, b, root);
}
/*
@@ -681,6 +695,72 @@ int dm_array_resize(struct dm_array_info *info, dm_block_t root,
}
EXPORT_SYMBOL_GPL(dm_array_resize);
+static int populate_ablock_with_values(struct dm_array_info *info, struct array_block *ab,
+ value_fn fn, void *context, unsigned base, unsigned new_nr)
+{
+ int r;
+ unsigned i;
+ uint32_t nr_entries;
+ struct dm_btree_value_type *vt = &info->value_type;
+
+ BUG_ON(le32_to_cpu(ab->nr_entries));
+ BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
+
+ nr_entries = le32_to_cpu(ab->nr_entries);
+ for (i = 0; i < new_nr; i++) {
+ r = fn(base + i, element_at(info, ab, i), context);
+ if (r)
+ return r;
+
+ if (vt->inc)
+ vt->inc(vt->context, element_at(info, ab, i));
+ }
+
+ ab->nr_entries = cpu_to_le32(new_nr);
+ return 0;
+}
+
+int dm_array_new(struct dm_array_info *info, dm_block_t *root,
+ uint32_t size, value_fn fn, void *context)
+{
+ int r;
+ struct dm_block *block;
+ struct array_block *ab;
+ unsigned block_index, end_block, size_of_block, max_entries;
+
+ r = dm_array_empty(info, root);
+ if (r)
+ return r;
+
+ size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
+ max_entries = calc_max_entries(info->value_type.size, size_of_block);
+ end_block = dm_div_up(size, max_entries);
+
+ for (block_index = 0; block_index != end_block; block_index++) {
+ r = alloc_ablock(info, size_of_block, max_entries, &block, &ab);
+ if (r)
+ break;
+
+ r = populate_ablock_with_values(info, ab, fn, context,
+ block_index * max_entries,
+ min(max_entries, size));
+ if (r) {
+ unlock_ablock(info, block);
+ break;
+ }
+
+ r = insert_ablock(info, block_index, block, root);
+ unlock_ablock(info, block);
+ if (r)
+ break;
+
+ size -= max_entries;
+ }
+
+ return r;
+}
+EXPORT_SYMBOL_GPL(dm_array_new);
+
int dm_array_del(struct dm_array_info *info, dm_block_t root)
{
return dm_btree_del(&info->btree_info, root);
diff --git a/drivers/md/persistent-data/dm-array.h b/drivers/md/persistent-data/dm-array.h
index ea177d6fa58f..45ea3f6e1ded 100644
--- a/drivers/md/persistent-data/dm-array.h
+++ b/drivers/md/persistent-data/dm-array.h
@@ -112,6 +112,25 @@ int dm_array_resize(struct dm_array_info *info, dm_block_t root,
__dm_written_to_disk(value);
/*
+ * Creates a new array populated with values provided by a callback
+ * function. This is more efficient than creating an empty array,
+ * resizing, and then setting values since that process incurs a lot of
+ * copying.
+ *
+ * Assumes 32bit values for now since it's only used by the cache hint
+ * array.
+ *
+ * info - describes the array
+ * root - the root block of the array on disk
+ * size - the number of entries in the array
+ * fn - the callback
+ * context - passed to the callback
+ */
+typedef int (*value_fn)(uint32_t index, void *value_le, void *context);
+int dm_array_new(struct dm_array_info *info, dm_block_t *root,
+ uint32_t size, value_fn fn, void *context);
+
+/*
* Frees a whole array. The value_type's decrement operation will be called
* for all values in the array
*/