[Qemu-devel] [PATCH v2] block: fix spoiling all dirty bitmaps by mirror and migration

[Vladimir Sementsov-Ogievskiy]

Mirror and migration use dirty bitmaps for their purposes, and since
commit [block: per caller dirty bitmap] they use their own bitmaps, not
the global one. But they use old functions bdrv_set_dirty and
bdrv_reset_dirty, which change all dirty bitmaps.

Named dirty bitmaps series by Fam and Snow are affected: mirroring and
migration will spoil all (not related to this mirroring or migration)
named dirty bitmaps.

This patch fixes this by adding bdrv_set_dirty_bitmap and
bdrv_reset_dirty_bitmap, which change concrete bitmap. Also, to prevent
such mistakes in future, old functions bdrv_(set,reset)_dirty are made
static, for internal block usage.

Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
CC: John Snow <address@hidden>
CC: Fam Zheng <address@hidden>
CC: Denis V. Lunev <address@hidden>
CC: Stefan Hajnoczi <address@hidden>
CC: Kevin Wolf <address@hidden>
---

This patch conflicts with
[PATCH v8 05/10] block: Add bdrv_copy_dirty_bitmap and bdrv_reset_dirty_bitmap
by John Snow, which introduces bdrv_reset_dirty_bitmap too, but it resets the 
whole
bitmap, not specified sectors range.

 block-migration.c     |  5 +++--
 block.c               | 23 ++++++++++++++++++++---
 block/mirror.c        | 11 +++++++----
 include/block/block.h |  6 ++++--
 4 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/block-migration.c b/block-migration.c
index 08db01a..5866987 100644
--- a/block-migration.c
+++ b/block-migration.c
@@ -303,7 +303,7 @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState 
*bmds)
     blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
                                 nr_sectors, blk_mig_read_cb, blk);
 
-    bdrv_reset_dirty(bs, cur_sector, nr_sectors);
+    bdrv_reset_dirty_bitmap(bs, bmds->dirty_bitmap, cur_sector, nr_sectors);
     qemu_mutex_unlock_iothread();
 
     bmds->cur_sector = cur_sector + nr_sectors;
@@ -496,7 +496,8 @@ static int mig_save_device_dirty(QEMUFile *f, 
BlkMigDevState *bmds,
                 g_free(blk);
             }
 
-            bdrv_reset_dirty(bmds->bs, sector, nr_sectors);
+            bdrv_reset_dirty_bitmap(bmds->bs, bmds->dirty_bitmap, sector,
+                                    nr_sectors);
             break;
         }
         sector += BDRV_SECTORS_PER_DIRTY_CHUNK;
diff --git a/block.c b/block.c
index a612594..4d12c0d 100644
--- a/block.c
+++ b/block.c
@@ -97,6 +97,10 @@ static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
 static QLIST_HEAD(, BlockDriver) bdrv_drivers =
     QLIST_HEAD_INITIALIZER(bdrv_drivers);
 
+static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
+                           int nr_sectors);
+static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
+                             int nr_sectors);
 /* If non-zero, use only whitelisted block drivers */
 static int use_bdrv_whitelist;
 
@@ -5361,8 +5365,20 @@ void bdrv_dirty_iter_init(BlockDriverState *bs,
     hbitmap_iter_init(hbi, bitmap->bitmap, 0);
 }
 
-void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
-                    int nr_sectors)
+void bdrv_set_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                           int64_t cur_sector, int nr_sectors)
+{
+    hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
+}
+
+void bdrv_reset_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                             int64_t cur_sector, int nr_sectors)
+{
+    hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
+}
+
+static void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector,
+                           int nr_sectors)
 {
     BdrvDirtyBitmap *bitmap;
     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
@@ -5370,7 +5386,8 @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t 
cur_sector,
     }
 }
 
-void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors)
+static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
+                             int nr_sectors)
 {
     BdrvDirtyBitmap *bitmap;
     QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) {
diff --git a/block/mirror.c b/block/mirror.c
index 2c6dd2a..9019d1b 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -128,7 +128,8 @@ static void mirror_write_complete(void *opaque, int ret)
         BlockDriverState *source = s->common.bs;
         BlockErrorAction action;
 
-        bdrv_set_dirty(source, op->sector_num, op->nb_sectors);
+        bdrv_set_dirty_bitmap(source, s->dirty_bitmap, op->sector_num,
+                              op->nb_sectors);
         action = mirror_error_action(s, false, -ret);
         if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) {
             s->ret = ret;
@@ -145,7 +146,8 @@ static void mirror_read_complete(void *opaque, int ret)
         BlockDriverState *source = s->common.bs;
         BlockErrorAction action;
 
-        bdrv_set_dirty(source, op->sector_num, op->nb_sectors);
+        bdrv_set_dirty_bitmap(source, s->dirty_bitmap, op->sector_num,
+                              op->nb_sectors);
         action = mirror_error_action(s, true, -ret);
         if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) {
             s->ret = ret;
@@ -286,7 +288,8 @@ static uint64_t coroutine_fn 
mirror_iteration(MirrorBlockJob *s)
         next_sector += sectors_per_chunk;
     }
 
-    bdrv_reset_dirty(source, sector_num, nb_sectors);
+    bdrv_reset_dirty_bitmap(source, s->dirty_bitmap, sector_num,
+                            nb_sectors);
 
     /* Copy the dirty cluster.  */
     s->in_flight++;
@@ -442,7 +445,7 @@ static void coroutine_fn mirror_run(void *opaque)
 
             assert(n > 0);
             if (ret == 1) {
-                bdrv_set_dirty(bs, sector_num, n);
+                bdrv_set_dirty_bitmap(bs, s->dirty_bitmap, sector_num, n);
                 sector_num = next;
             } else {
                 sector_num += n;
diff --git a/include/block/block.h b/include/block/block.h
index 5450610..237ddb0 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -433,8 +433,10 @@ BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState 
*bs, int granularity,
 void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
 BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs);
 int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t 
sector);
-void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors);
-void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, int 
nr_sectors);
+void bdrv_set_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                           int64_t cur_sector, int nr_sectors);
+void bdrv_reset_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap,
+                             int64_t cur_sector, int nr_sectors);
 void bdrv_dirty_iter_init(BlockDriverState *bs,
                           BdrvDirtyBitmap *bitmap, struct HBitmapIter *hbi);
 int64_t bdrv_get_dirty_count(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
-- 
1.9.1