On 01.06.2017 01:58, John Snow wrote:
On 05/19/2017 07:02 PM, John Snow wrote:
On 05/03/2017 08:25 AM, Vladimir Sementsov-Ogievskiy wrote:
It will be needed in following commits for persistent bitmaps.
If bitmap is loaded from read-only storage (and we can't mark it
"in use" in this storage) corresponding BdrvDirtyBitmap should be
read-only.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
block/dirty-bitmap.c | 16 ++++++++++++++++
include/block/dirty-bitmap.h | 3 +++
2 files changed, 19 insertions(+)
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 90af37287f..ab6a95cf41 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -44,6 +44,8 @@ struct BdrvDirtyBitmap {
int64_t size; /* Size of the bitmap (Number of sectors) */
bool disabled; /* Bitmap is read-only */
int active_iterators; /* How many iterators are active */
+ bool readonly; /* Bitmap is read-only and may be changed only
+ by deserialize* functions */
QLIST_ENTRY(BdrvDirtyBitmap) list;
};
@@ -436,6 +438,7 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap,
int64_t cur_sector, int64_t nr_sectors)
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
+ assert(!bdrv_dirty_bitmap_readonly(bitmap));
Doesn't this change the nature of the assertion?
We're going from
return !(bitmap->disabled || bitmap->successor);
to
!bitmap->readonly
That makes me a little nervous to ACK this patch, because the
correctness depends on how readonly is updated and manipulated in the
future, which makes it more prone to error.
I must have been *REALLY* tired when I sent this; I had thought you were
replacing an assertion instead of just adding one.
I'm sorry about that.
I thought so, don't worry)
hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
}
@@ -443,12 +446,14 @@ void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
int64_t cur_sector, int64_t nr_sectors)
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
+ assert(!bdrv_dirty_bitmap_readonly(bitmap));
hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors);
}
void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
+ assert(!bdrv_dirty_bitmap_readonly(bitmap));
if (!out) {
hbitmap_reset_all(bitmap->bitmap);
} else {
@@ -519,6 +524,7 @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t
cur_sector,
if (!bdrv_dirty_bitmap_enabled(bitmap)) {
continue;
}
+ assert(!bdrv_dirty_bitmap_readonly(bitmap));
hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
}
}
@@ -540,3 +546,13 @@ int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap)
{
return hbitmap_count(bitmap->meta);
}
+
+bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap)
+{
+ return bitmap->readonly;
+}
+
+void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap)
+{
+ bitmap->readonly = true;
+}
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 1e17729ac2..0aab5841f5 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -75,4 +75,7 @@ void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap
*bitmap,
bool finish);
void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap);
+bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap);
+void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap);
+
#endif
--
Best regards,
Vladimir.