From: Liran Schour <lirans@il.ibm.com>
Date: Tue, 26 Jan 2010 08:31:48 +0000 (+0200)
Subject: Count dirty blocks and expose an API to get dirty count
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=aaa0eb75e2e56d483c89731a447c999985713b43;p=qemu.git

Count dirty blocks and expose an API to get dirty count

This will manage dirty counter for each device and will allow to get the
dirty counter from above.

Signed-off-by: Liran Schour <lirans@il.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---

diff --git a/block.c b/block.c
index 1919d19732..e9fd8808bb 100644
--- a/block.c
+++ b/block.c
@@ -686,9 +686,15 @@ static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
         bit = start % (sizeof(unsigned long) * 8);
         val = bs->dirty_bitmap[idx];
         if (dirty) {
-            val |= 1 << bit;
+            if (!(val & (1 << bit))) {
+                bs->dirty_count++;
+                val |= 1 << bit;
+            }
         } else {
-            val &= ~(1 << bit);
+            if (val & (1 << bit)) {
+                bs->dirty_count--;
+                val &= ~(1 << bit);
+            }
         }
         bs->dirty_bitmap[idx] = val;
     }
@@ -2139,6 +2145,7 @@ void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
 {
     int64_t bitmap_size;
 
+    bs->dirty_count = 0;
     if (enable) {
         if (!bs->dirty_bitmap) {
             bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
@@ -2173,3 +2180,8 @@ void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
 {
     set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
 }
+
+int64_t bdrv_get_dirty_count(BlockDriverState *bs)
+{
+    return bs->dirty_count;
+}
diff --git a/block.h b/block.h
index ecf66c52ab..536265e86c 100644
--- a/block.h
+++ b/block.h
@@ -200,4 +200,5 @@ void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable);
 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector);
 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
                       int nr_sectors);
+int64_t bdrv_get_dirty_count(BlockDriverState *bs);
 #endif
diff --git a/block_int.h b/block_int.h
index a0ebd90a0b..223a437b6a 100644
--- a/block_int.h
+++ b/block_int.h
@@ -175,6 +175,7 @@ struct BlockDriverState {
     int type;
     char device_name[32];
     unsigned long *dirty_bitmap;
+    int64_t dirty_count;
     BlockDriverState *next;
     void *private;
 };