[Qemu-devel] [RFC V4 29/30] qcow2: init and cleanup deduplication.

["Benoît Canet" <benoit@irqsave.net>]

Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
 block/qcow2-dedup.c |   78 +++++++++++++++++++++++++++++++++++++++++++++++----
 block/qcow2.c       |   17 ++++++++---
 2 files changed, 86 insertions(+), 9 deletions(-)

diff --git a/block/qcow2-dedup.c b/block/qcow2-dedup.c
index bd8397e..da1a668 100644
--- a/block/qcow2-dedup.c
+++ b/block/qcow2-dedup.c
@@ -1014,20 +1014,88 @@ void coroutine_fn qcow2_co_load_dedup_hashes(void *opaque)
     }
 }
 
+static gint qcow2_dedup_compare_by_hash(gconstpointer a,
+                                        gconstpointer b,
+                                        gpointer data)
+{
+    QCowHash *hash_a = (QCowHash *) a;
+    QCowHash *hash_b = (QCowHash *) b;
+    return memcmp(hash_a->data, hash_b->data, HASH_LENGTH);
+}
+
+static void qcow2_dedup_destroy_qcow_hash_node(gpointer p)
+{
+    QCowHashNode *hash_node = (QCowHashNode *) p;
+    g_free(hash_node);
+}
+
+static gint qcow2_dedup_compare_by_offset(gconstpointer a,
+                                          gconstpointer b,
+                                          gpointer data)
+{
+    uint64_t offset_a = *((uint64_t *) a);
+    uint64_t offset_b = *((uint64_t *) b);
+
+    if (offset_a > offset_b) {
+        return 1;
+    }
+    if (offset_a < offset_b) {
+        return -1;
+    }
+    return 0;
+}
+
 int qcow2_dedup_init(BlockDriverState *bs)
 {
     BDRVQcowState *s = bs->opaque;
-    return qcow2_do_table_init(bs,
-                               &s->dedup_table,
-                               s->dedup_table_offset,
-                               s->dedup_table_size,
-                               false);
+    Coroutine *co;
+    int ret;
+
+    s->has_dedup = true;
+
+    ret = qcow2_do_table_init(bs,
+                              &s->dedup_table,
+                              s->dedup_table_offset,
+                              s->dedup_table_size,
+                              false);
+
+    if (ret < 0) {
+        return ret;
+    }
+
+    /* if we are read-only we don't deduplicate anything */
+    if (bs->read_only) {
+        return 0;
+    }
+
+    s->dedup_tree_by_hash = g_tree_new_full(qcow2_dedup_compare_by_hash, NULL,
+                                            NULL,
+                                            qcow2_dedup_destroy_qcow_hash_node);
+    s->dedup_tree_by_sect = g_tree_new_full(qcow2_dedup_compare_by_offset,
+                                              NULL, NULL, NULL);
+
+    s->dedup_cluster_cache = qcow2_cache_create(bs, DEDUP_CACHE_SIZE,
+                                                s->hash_block_size);
+
+    /* load asynchronously the hashes */
+    co = qemu_coroutine_create(qcow2_co_load_dedup_hashes);
+    qemu_coroutine_enter(co, bs);
+    return 0;
 }
 
 void qcow2_dedup_close(BlockDriverState *bs)
 {
     BDRVQcowState *s = bs->opaque;
     g_free(s->dedup_table);
+
+    if (bs->read_only) {
+        return;
+    }
+
+    qcow2_cache_flush(bs, s->dedup_cluster_cache);
+    qcow2_cache_destroy(bs, s->dedup_cluster_cache);
+    g_tree_destroy(s->dedup_tree_by_sect);
+    g_tree_destroy(s->dedup_tree_by_hash);
 }
 
 /* Clean the last reference to a given cluster when it's refcount is zero
diff --git a/block/qcow2.c b/block/qcow2.c
index f1e0f5f..d534077 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -539,6 +539,13 @@ static int qcow2_open(BlockDriverState *bs, int flags)
         }
     }
 
+    if (s->incompatible_features & QCOW2_INCOMPAT_DEDUP) {
+        ret = qcow2_dedup_init(bs);
+        if (ret < 0) {
+            goto fail;
+        }
+    }
+
 #ifdef DEBUG_ALLOC
     {
         BdrvCheckResult result = {0};
@@ -1003,11 +1010,11 @@ fail:
 static void qcow2_close(BlockDriverState *bs)
 {
     BDRVQcowState *s = bs->opaque;
+
     g_free(s->l1_table);
 
     if (s->has_dedup) {
-        qcow2_cache_flush(bs, s->dedup_cluster_cache);
-        qcow2_cache_destroy(bs, s->dedup_cluster_cache);
+        qcow2_dedup_close(bs);
     }
 
     qcow2_cache_flush(bs, s->l2_table_cache);
@@ -1498,8 +1505,10 @@ static int qcow2_create2(const char *filename, int64_t total_size,
         }
 
         /* minimal init */
-        s->dedup_cluster_cache = qcow2_cache_create(bs, DEDUP_CACHE_SIZE,
-                                                    s->hash_block_size);
+        ret = qcow2_dedup_init(bs);
+        if (ret < 0) {
+            goto out;
+        }
     }
 
     /* Want a backing file? There you go.*/
-- 
1.7.10.4