This message does not make any sense when it appears as the response to
making an R/W node read-only. We should detect that case and emit a
different message, then.
Signed-off-by: Max Reitz
---
block.c | 17 -
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/block.c b/block.c
index 16ef5edfd8..af662d5f17 100644
--- a/block.c
+++ b/block.c
@@ -1689,6 +1689,8 @@ static int bdrv_child_check_perm(BdrvChild *c,
BlockReopenQueue *q,
GSList *ignore_children, Error **errp);
static void bdrv_child_abort_perm_update(BdrvChild *c);
static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared);
+static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
+ uint64_t *shared_perm);
typedef struct BlockReopenQueueEntry {
bool prepared;
@@ -1775,7 +1777,20 @@ static int bdrv_check_perm(BlockDriverState *bs,
BlockReopenQueue *q,
if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) &&
!bdrv_is_writable_after_reopen(bs, q))
{
-error_setg(errp, "Block node is read-only");
+if (!bdrv_is_writable_after_reopen(bs, NULL)) {
+error_setg(errp, "Block node is read-only");
+} else {
+uint64_t current_perms, current_shared;
+bdrv_get_cumulative_perm(bs, _perms, _shared);
+if (current_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) {
+error_setg(errp, "Cannot make block node read-only, there is "
+ "a writer on it");
+} else {
+error_setg(errp, "Cannot make block node read-only and create "
+ "a writer on it");
+}
+}
+
return -EPERM;
}
--
2.21.0
