[PULL,v2,09/12] block: use bdrv_can_set_read_only() during reopen

Commit Message

Jeff Cody April 24, 2017, 7:19 p.m. UTC

Signed-off-by: Jeff Cody <[e-mail]>
Reviewed-by: Stefan Hajnoczi <[e-mail]>
Reviewed-by: John Snow <[e-mail]>
Message-id: [e-mail]
---
 block.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

Patch

diff --git a/block.c b/block.c
index 1ac05c1..5db266b 100644
--- a/block.c
+++ b/block.c
@@ -2789,6 +2789,7 @@  int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
     BlockDriver *drv;
     QemuOpts *opts;
     const char *value;
+    bool read_only;
 
     assert(reopen_state != NULL);
     assert(reopen_state->bs->drv != NULL);
@@ -2817,12 +2818,13 @@  int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
         qdict_put(reopen_state->options, "driver", qstring_from_str(value));
     }
 
-    /* if we are to stay read-only, do not allow permission change
-     * to r/w */
-    if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) &&
-        reopen_state->flags & BDRV_O_RDWR) {
-        error_setg(errp, "Node '%s' is read only",
-                   bdrv_get_device_or_node_name(reopen_state->bs));
+    /* If we are to stay read-only, do not allow permission change
+     * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
+     * not set, or if the BDS still has copy_on_read enabled */
+    read_only = !(reopen_state->flags & BDRV_O_RDWR);
+    ret = bdrv_can_set_read_only(reopen_state->bs, read_only, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
         goto error;
     }