diff mbox

[v4,1/9] qapi: Add optional field "name" to block dirty bitmap

Message ID 1395911388-31027-2-git-send-email-famz@redhat.com
State New
Headers show

Commit Message

Fam Zheng March 27, 2014, 9:09 a.m. UTC 
This field will be set for user created dirty bitmap. Also pass in an
error pointer to bdrv_create_dirty_bitmap, so when a name is already
taken on this BDS, it can report an error message. This is not global
check, two BDSes can have dirty bitmap with a common name.

Implemented bdrv_find_dirty_bitmap to find a dirty bitmap by name, will
be used later when other QMP commands want to reference dirty bitmap by
name.

Add bdrv_dirty_bitmap_make_anon. This unsets the name of dirty bitmap.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block-migration.c     |  3 ++-
 block.c               | 33 ++++++++++++++++++++++++++++++++-
 block/mirror.c        |  2 +-
 include/block/block.h |  8 +++++++-
 qapi-schema.json      |  4 +++-
 5 files changed, 45 insertions(+), 5 deletions(-)

Comments

Stefan Hajnoczi March 27, 2014, 3:30 p.m. UTC | #1 
On Thu, Mar 27, 2014 at 05:09:40PM +0800, Fam Zheng wrote:
> @@ -5079,18 +5080,45 @@ bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
>      return true;
>  }
>  
> -BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity)
> +BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
> +{
> +    BdrvDirtyBitmap *bm;
> +    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
> +        if (!strcmp(name, bm->name)) {
> +            return bm;
> +        }
> +    }
> +    return NULL;
> +}
> +
> +void bdrv_dirty_bitmap_make_anon(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
> +{
> +    g_free(bitmap->name);
> +    bitmap->name = NULL;
> +}

This looks dangerous since strcmp() does not check for NULL pointers.  I
guess you need to add a check to bdrv_find_dirty_bitmap().

> @@ -5120,6 +5149,8 @@ BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
>          info->count = bdrv_get_dirty_count(bs, bm);
>          info->granularity =
>              ((int64_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bm->bitmap));
> +        info->has_name = bm->name[0] != '\0';
> +        info->name = g_strdup(bm->name);

This looks dangerous too.  What if ->name is NULL?
Fam Zheng April 1, 2014, 7:41 a.m. UTC | #2 
On Thu, 03/27 16:30, Stefan Hajnoczi wrote:
> On Thu, Mar 27, 2014 at 05:09:40PM +0800, Fam Zheng wrote:
> > @@ -5079,18 +5080,45 @@ bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
> >      return true;
> >  }
> >  
> > -BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity)
> > +BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
> > +{
> > +    BdrvDirtyBitmap *bm;
> > +    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
> > +        if (!strcmp(name, bm->name)) {
> > +            return bm;
> > +        }
> > +    }
> > +    return NULL;
> > +}
> > +
> > +void bdrv_dirty_bitmap_make_anon(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
> > +{
> > +    g_free(bitmap->name);
> > +    bitmap->name = NULL;
> > +}
> 
> This looks dangerous since strcmp() does not check for NULL pointers.  I
> guess you need to add a check to bdrv_find_dirty_bitmap().

OK.

> 
> > @@ -5120,6 +5149,8 @@ BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
> >          info->count = bdrv_get_dirty_count(bs, bm);
> >          info->granularity =
> >              ((int64_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bm->bitmap));
> > +        info->has_name = bm->name[0] != '\0';
> > +        info->name = g_strdup(bm->name);
> 
> This looks dangerous too.  What if ->name is NULL?

Will add a check here.

Thanks,
Fam
diff mbox

Patch

diff --git a/block-migration.c b/block-migration.c
index 897fdba..e6e016a 100644
--- a/block-migration.c
+++ b/block-migration.c
@@ -315,7 +315,8 @@  static void set_dirty_tracking(void)
     BlkMigDevState *bmds;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
-        bmds->dirty_bitmap = bdrv_create_dirty_bitmap(bmds->bs, BLOCK_SIZE);
+        bmds->dirty_bitmap = bdrv_create_dirty_bitmap(bmds->bs, BLOCK_SIZE,
+                                                      NULL, NULL);
     }
 }
 
diff --git a/block.c b/block.c
index acb70fd..3f880d6 100644
--- a/block.c
+++ b/block.c
@@ -52,6 +52,7 @@ 
 
 struct BdrvDirtyBitmap {
     HBitmap *bitmap;
+    char *name;
     QLIST_ENTRY(BdrvDirtyBitmap) list;
 };
 
@@ -5079,18 +5080,45 @@  bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
     return true;
 }
 
-BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity)
+BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs, const char *name)
+{
+    BdrvDirtyBitmap *bm;
+    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
+        if (!strcmp(name, bm->name)) {
+            return bm;
+        }
+    }
+    return NULL;
+}
+
+void bdrv_dirty_bitmap_make_anon(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
+{
+    g_free(bitmap->name);
+    bitmap->name = NULL;
+}
+
+BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
+                                          int granularity,
+                                          const char *name,
+                                          Error **errp)
 {
     int64_t bitmap_size;
     BdrvDirtyBitmap *bitmap;
 
     assert((granularity & (granularity - 1)) == 0);
 
+    if (name && bdrv_find_dirty_bitmap(bs, name)) {
+        error_setg(errp, "Bitmap already exists: %s", name);
+        return NULL;
+    }
     granularity >>= BDRV_SECTOR_BITS;
     assert(granularity);
     bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS);
     bitmap = g_malloc0(sizeof(BdrvDirtyBitmap));
     bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1);
+    if (name) {
+        bitmap->name = g_strdup(name);
+    }
     QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list);
     return bitmap;
 }
@@ -5102,6 +5130,7 @@  void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap)
         if (bm == bitmap) {
             QLIST_REMOVE(bitmap, list);
             hbitmap_free(bitmap->bitmap);
+            g_free(bitmap->name);
             g_free(bitmap);
             return;
         }
@@ -5120,6 +5149,8 @@  BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
         info->count = bdrv_get_dirty_count(bs, bm);
         info->granularity =
             ((int64_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bm->bitmap));
+        info->has_name = bm->name[0] != '\0';
+        info->name = g_strdup(bm->name);
         entry->value = info;
         *plist = entry;
         plist = &entry->next;
diff --git a/block/mirror.c b/block/mirror.c
index 0ef41f9..9b73cd9 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -605,7 +605,7 @@  static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
     s->granularity = granularity;
     s->buf_size = MAX(buf_size, granularity);
 
-    s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity);
+    s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
     bdrv_set_enable_write_cache(s->target, true);
     bdrv_set_on_error(s->target, on_target_error, on_target_error);
     bdrv_iostatus_enable(s->target);
diff --git a/include/block/block.h b/include/block/block.h
index 1ed55d8..aa30b2a 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -428,7 +428,13 @@  bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
 
 struct HBitmapIter;
 typedef struct BdrvDirtyBitmap BdrvDirtyBitmap;
-BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity);
+BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs,
+                                          int granularity,
+                                          const char *name,
+                                          Error **errp);
+BdrvDirtyBitmap *bdrv_find_dirty_bitmap(BlockDriverState *bs,
+                                        const char *name);
+void bdrv_dirty_bitmap_make_anon(BlockDriverState *bs, BdrvDirtyBitmap *bitmap);
 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);
diff --git a/qapi-schema.json b/qapi-schema.json
index 391356f..506c242 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1029,6 +1029,8 @@ 
 #
 # Block dirty bitmap information.
 #
+# @name: #optional the name of dirty bitmap (Since 2.1)
+#
 # @count: number of dirty bytes according to the dirty bitmap
 #
 # @granularity: granularity of the dirty bitmap in bytes (since 1.4)
@@ -1036,7 +1038,7 @@ 
 # Since: 1.3
 ##
 { 'type': 'BlockDirtyInfo',
-  'data': {'count': 'int', 'granularity': 'int'} }
+  'data': {'*name': 'str', 'count': 'int', 'granularity': 'int'} }
 
 ##
 # @BlockInfo: