block/dirty-bitmaps: add user_locked status checker

Instead of both frozen and qmp_locked checks, wrap it into one check.
frozen implies the bitmap is split in two (for backup), and shouldn't
be modified. qmp_locked implies it's being used by another operation,
like being exported over NBD. In both cases it means we shouldn't allow
the user to modify it in any meaningful way.

Replace any usages where we check both frozen and qmp_locked with the
new check.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20181002230218.13949-2-jsnow@redhat.com
[w/edits Suggested-By: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]
Signed-off-by: John Snow <jsnow@redhat.com>

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 8ac933cf1cc190f0885d0b0a6f113654a3c5760a..9603cdd29bf3437354d49cd4a7c7cd8ffc504bce 100644 (file)
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -176,6 +176,12 @@ bool bdrv_dirty_bitmap_frozen(BdrvDirtyBitmap *bitmap)
     return bitmap->successor;
 }
 
+/* Both conditions disallow user-modification via QMP. */
+bool bdrv_dirty_bitmap_user_locked(BdrvDirtyBitmap *bitmap) {
+    return bdrv_dirty_bitmap_frozen(bitmap) ||
+           bdrv_dirty_bitmap_qmp_locked(bitmap);
+}
+
 void bdrv_dirty_bitmap_set_qmp_locked(BdrvDirtyBitmap *bitmap, bool qmp_locked)
 {
     qemu_mutex_lock(bitmap->mutex);

diff --git a/blockdev.c b/blockdev.c
index d685bb7746ba8a0643fe9573e8750f7e80be36ef..9da0cf1a7202832a33e8dd217daa5236aaff5985 100644 (file)
--- a/blockdev.c
+++ b/blockdev.c
@@ -2010,11 +2010,8 @@ static void block_dirty_bitmap_clear_prepare(BlkActionState *common,
         return;
     }
 
-    if (bdrv_dirty_bitmap_frozen(state->bitmap)) {
-        error_setg(errp, "Cannot modify a frozen bitmap");
-        return;
-    } else if (bdrv_dirty_bitmap_qmp_locked(state->bitmap)) {
-        error_setg(errp, "Cannot modify a locked bitmap");
+    if (bdrv_dirty_bitmap_user_locked(state->bitmap)) {
+        error_setg(errp, "Cannot modify a bitmap in use by another operation");
         return;
     } else if (!bdrv_dirty_bitmap_enabled(state->bitmap)) {
         error_setg(errp, "Cannot clear a disabled bitmap");
@@ -2883,15 +2880,10 @@ void qmp_block_dirty_bitmap_remove(const char *node, const char *name,
         return;
     }
 
-    if (bdrv_dirty_bitmap_frozen(bitmap)) {
-        error_setg(errp,
-                   "Bitmap '%s' is currently frozen and cannot be removed",
-                   name);
-        return;
-    } else if (bdrv_dirty_bitmap_qmp_locked(bitmap)) {
+    if (bdrv_dirty_bitmap_user_locked(bitmap)) {
         error_setg(errp,
-                   "Bitmap '%s' is currently locked and cannot be removed",
-                   name);
+                   "Bitmap '%s' is currently in use by another operation and"
+                   " cannot be removed", name);
         return;
     }
 
@@ -2921,15 +2913,10 @@ void qmp_block_dirty_bitmap_clear(const char *node, const char *name,
         return;
     }
 
-    if (bdrv_dirty_bitmap_frozen(bitmap)) {
+    if (bdrv_dirty_bitmap_user_locked(bitmap)) {
         error_setg(errp,
-                   "Bitmap '%s' is currently frozen and cannot be modified",
-                   name);
-        return;
-    } else if (bdrv_dirty_bitmap_qmp_locked(bitmap)) {
-        error_setg(errp,
-                   "Bitmap '%s' is currently locked and cannot be modified",
-                   name);
+                   "Bitmap '%s' is currently in use by another operation"
+                   " and cannot be cleared", name);
         return;
     } else if (!bdrv_dirty_bitmap_enabled(bitmap)) {
         error_setg(errp,

diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 201ff7f20b04ea6e23e9b50ddeb3b87ba67711eb..14639439a2f7c55eb7f0a2a4e16a8a79567e1d56 100644 (file)
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -94,6 +94,7 @@ bool bdrv_has_readonly_bitmaps(BlockDriverState *bs);
 bool bdrv_dirty_bitmap_get_autoload(const BdrvDirtyBitmap *bitmap);
 bool bdrv_dirty_bitmap_get_persistance(BdrvDirtyBitmap *bitmap);
 bool bdrv_dirty_bitmap_qmp_locked(BdrvDirtyBitmap *bitmap);
+bool bdrv_dirty_bitmap_user_locked(BdrvDirtyBitmap *bitmap);
 bool bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs);
 BdrvDirtyBitmap *bdrv_dirty_bitmap_next(BlockDriverState *bs,
                                         BdrvDirtyBitmap *bitmap);

diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index 477826330c14b3eb3e1dc05e8fa7e6f3fffa6b27..dfbfb853b762602cf3459a2af5128efb004449a6 100644 (file)
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -301,14 +301,8 @@ static int init_dirty_bitmap_migration(void)
                 goto fail;
             }
 
-            if (bdrv_dirty_bitmap_frozen(bitmap)) {
-                error_report("Can't migrate frozen dirty bitmap: '%s",
-                             bdrv_dirty_bitmap_name(bitmap));
-                goto fail;
-            }
-
-            if (bdrv_dirty_bitmap_qmp_locked(bitmap)) {
-                error_report("Can't migrate locked dirty bitmap: '%s",
+            if (bdrv_dirty_bitmap_user_locked(bitmap)) {
+                error_report("Can't migrate a bitmap that is in use by another operation: '%s'",
                              bdrv_dirty_bitmap_name(bitmap));
                 goto fail;
             }