diff options
| -rw-r--r-- | block.c | 17 |
1 files changed, 16 insertions, 1 deletions
@@ -1709,6 +1709,8 @@ 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; @@ -1795,7 +1797,20 @@ 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, ¤t_perms, ¤t_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; } |