Re: [Qemu-devel] [PATCH v5 4/7] block: Add checks of blocker in block operations

[Fam Zheng]

On 2013年11月27日 00:13, Paolo Bonzini wrote:

Il 26/11/2013 05:05, Fam Zheng ha scritto:

--- a/blockdev.c
+++ b/blockdev.c
@@ -1001,6 +1001,11 @@ SnapshotInfo 
*qmp_blockdev_snapshot_delete_internal_sync(const char *device,
          return NULL;
      }

+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE,
+                           errp)) {
+        return NULL;
+    }

Why not check in bdrv_snapshot_delete...

      ret = bdrv_snapshot_find_by_id_and_name(bs, id, name, &sn, &local_err);
      if (error_is_set(&local_err)) {
          error_propagate(errp, local_err);
@@ -1098,6 +1103,10 @@ static void 
internal_snapshot_prepare(BlkTransactionState *common,
          return;
      }

+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_INTERNAL_SNAPSHOT, errp)) {
+        return;
+    }

... and bdrv_snapshot_create?

OK.

      if (!bdrv_is_inserted(bs)) {
          error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
          return;
@@ -1536,6 +1545,10 @@ void qmp_change_blockdev(const char *device, const char 
*filename,
          return;
      }

+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_CHANGE, errp)) {
+        return;
+    }
+
      if (format) {
          drv = bdrv_find_whitelisted_format(format, bs->read_only);
          if (!drv) {
@@ -1684,6 +1697,10 @@ void qmp_block_resize(const char *device, int64_t size, 
Error **errp)
          return;
      }

+    if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, errp)) {
+        return;
+    }
+
      if (size < 0) {
          error_set(errp, QERR_INVALID_PARAMETER_VALUE, "size", "a >0 size");
          return;
--

This should be redundant since bdrv_truncate already checks.

It doesn't hurt and skips bdrv_drain_all if op is blocked.

Fam