[Qemu-devel] [RFC V4 10/30] qcow2: Add qcow2_dedup_grow_table and use it.

["Benoît Canet" <benoit@irqsave.net>]

Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
 block/qcow2-dedup.c |   44 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/block/qcow2-dedup.c b/block/qcow2-dedup.c
index 7adaaba..b998a2d 100644
--- a/block/qcow2-dedup.c
+++ b/block/qcow2-dedup.c
@@ -38,6 +38,44 @@ static int qcow2_dedup_read_write_hash(BlockDriverState *bs,
                                        bool write);
 
 /*
+ * Save the dedup table information into the header extensions
+ *
+ * @table_offset: the dedup table offset in the QCOW2 file
+ * @size:         the size of the dedup table
+ * @ret:          0 on success, -errno  on error
+ */
+static int qcow2_dedup_save_table_info(BlockDriverState *bs,
+                                  int64_t table_offset, int size)
+{
+    BDRVQcowState *s = bs->opaque;
+    s->dedup_table_offset = table_offset;
+    s->dedup_table_size = size;
+    return qcow2_update_header(bs);
+}
+
+/*
+ * Grow the deduplication table
+ *
+ * @min_size:   minimal size
+ * @exact_size: if true force to grow to the exact size
+ * @ret:        0 on success, -errno  on error
+ */
+static int qcow2_dedup_grow_table(BlockDriverState *bs,
+                                  int min_size,
+                                  bool exact_size)
+{
+    BDRVQcowState *s = bs->opaque;
+    return qcow2_do_grow_table(bs,
+                               min_size,
+                               exact_size,
+                               &s->dedup_table,
+                               &s->dedup_table_offset,
+                               &s->dedup_table_size,
+                               qcow2_dedup_save_table_info,
+                               "dedup");
+}
+
+/*
  * Prepare a buffer containing all the required data required to compute cluster
  * sized deduplication hashes.
  * If sector_num or nb_sectors are not cluster-aligned, missing data
@@ -712,7 +750,11 @@ static int qcow2_dedup_read_write_hash(BlockDriverState *bs,
     index_in_dedup_table = cluster_number / nb_hash_in_block;
 
     if (s->dedup_table_size <= index_in_dedup_table) {
-        return -ENOSPC;
+        ret = qcow2_dedup_grow_table(bs, index_in_dedup_table + 1, false);
+    }
+
+    if (ret < 0) {
+        return ret;
     }
 
     /* if we must read and there is nothing to read return a null hash */
-- 
1.7.10.4