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authorVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>2017-06-28 15:05:10 +0300
committerMax Reitz <mreitz@redhat.com>2017-07-11 17:44:58 +0200
commitd6883bc96890dae97757ee8a61aab7f18d9a66de (patch)
tree615468c1c9098a4062e888df16f9f4fbebaa3a30 /block/dirty-bitmap.c
parent8bfc932e1eaab86788bb08207d520bd2804422ae (diff)
block/dirty-bitmap: add readonly field to BdrvDirtyBitmap
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 <vsementsov@virtuozzo.com> Message-id: 20170628120530.31251-11-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block/dirty-bitmap.c')
-rw-r--r--block/dirty-bitmap.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index a8fe149c4a..17d3068336 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -46,6 +46,12 @@ struct BdrvDirtyBitmap {
bool disabled; /* Bitmap is disabled. It ignores all writes to
the device */
int active_iterators; /* How many iterators are active */
+ bool readonly; /* Bitmap is read-only. This field also
+ prevents the respective image from being
+ modified (i.e. blocks writes and discards).
+ Such operations must fail and both the image
+ and this bitmap must remain unchanged while
+ this flag is set. */
QLIST_ENTRY(BdrvDirtyBitmap) list;
};
@@ -505,6 +511,7 @@ void bdrv_set_dirty_bitmap_locked(BdrvDirtyBitmap *bitmap,
int64_t cur_sector, int64_t nr_sectors)
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
+ assert(!bdrv_dirty_bitmap_readonly(bitmap));
hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors);
}
@@ -521,6 +528,7 @@ void bdrv_reset_dirty_bitmap_locked(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);
}
@@ -535,6 +543,7 @@ void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap,
void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out)
{
assert(bdrv_dirty_bitmap_enabled(bitmap));
+ assert(!bdrv_dirty_bitmap_readonly(bitmap));
bdrv_dirty_bitmap_lock(bitmap);
if (!out) {
hbitmap_reset_all(bitmap->bitmap);
@@ -551,6 +560,7 @@ void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in)
{
HBitmap *tmp = bitmap->bitmap;
assert(bdrv_dirty_bitmap_enabled(bitmap));
+ assert(!bdrv_dirty_bitmap_readonly(bitmap));
bitmap->bitmap = in;
hbitmap_free(tmp);
}
@@ -613,6 +623,7 @@ 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);
}
bdrv_dirty_bitmaps_unlock(bs);
@@ -635,3 +646,28 @@ 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;
+}
+
+/* Called with BQL taken. */
+void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value)
+{
+ qemu_mutex_lock(bitmap->mutex);
+ bitmap->readonly = value;
+ qemu_mutex_unlock(bitmap->mutex);
+}
+
+bool bdrv_has_readonly_bitmaps(BlockDriverState *bs)
+{
+ BdrvDirtyBitmap *bm;
+ QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
+ if (bm->readonly) {
+ return true;
+ }
+ }
+
+ return false;
+}