[Qemu-devel] [RFC V2 09/20] qcow2: Add qcow2_co_load_dedup_hashes.

[Benoît Canet]

This coroutine load all the hashes in the red black tree at startup.
---
 block/qcow2-dedup.c |   44 ++++++++++++++++++++++++++++++++++++++++++++
 block/qcow2.h       |    1 +
 2 files changed, 45 insertions(+)

diff --git a/block/qcow2-dedup.c b/block/qcow2-dedup.c
index c626720..a2f6657 100644
--- a/block/qcow2-dedup.c
+++ b/block/qcow2-dedup.c
@@ -634,3 +634,47 @@ int qcow2_dedup_write_new_hashes(BlockDriverState *bs,
 fail:
     return ret;
 }
+
+/*
+ * This coroutine load the deduplication hashes in the red black tree
+ *
+ * @data: the given BlockDriverState
+ * @ret:  NULL
+ */
+void coroutine_fn qcow2_co_load_dedup_hashes(void *opaque)
+{
+    BlockDriverState *bs = opaque;
+    BDRVQcowState *s = bs->opaque;
+    int ret;
+    uint8_t *hash = NULL;
+    uint8_t null_hash[HASH_LENGTH];
+    uint64_t max_cluster_offset, i;
+    int nb_hash_in_dedup_cluster = s->cluster_size / HASH_LENGTH;
+
+    /* prepare the null hash */
+    memset(null_hash, 0, HASH_LENGTH);
+
+    max_cluster_offset = s->dedup_table_size * nb_hash_in_dedup_cluster;
+
+    for (i = 0; i < max_cluster_offset; i++) {
+        /* get the hash */
+        qemu_co_mutex_lock(&s->lock);
+        ret = qcow2_dedup_read_write_hash(bs, &hash,
+                                          i * s->cluster_sectors,
+                                          false);
+        qemu_co_mutex_unlock(&s->lock);
+        if (ret < 0) {
+            error_report("Failed to load deduplication hash.");
+        }
+
+        /* if the hash is not null load it into red black tree */
+        if (memcmp(hash, null_hash, HASH_LENGTH)) {
+            qemu_co_mutex_lock(&s->lock);
+            qcow2_dedup_insert_hash_in_rb_tree(bs, hash,
+                                               i * s->cluster_sectors);
+            qemu_co_mutex_unlock(&s->lock);
+        } else {
+            free(hash);
+        }
+    }
+}
diff --git a/block/qcow2.h b/block/qcow2.h
index 58aee77..5bab6e2 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -375,5 +375,6 @@ int qcow2_dedup(BlockDriverState *bs,
 int qcow2_dedup_write_new_hashes(BlockDriverState *bs,
                                  uint64_t cluster_offset,
                                  int count);
+void coroutine_fn qcow2_co_load_dedup_hashes(void *opaque);
 
 #endif
-- 
1.7.10.4