diff options
author | Kevin Wolf <kwolf@redhat.com> | 2019-01-31 15:16:10 +0100 |
---|---|---|
committer | Kevin Wolf <kwolf@redhat.com> | 2019-02-01 13:46:45 +0100 |
commit | 78fc3b3a26c145eebcdee992988644974b243a74 (patch) | |
tree | 0100f643023837f66fb19488ea581f09e3a5e9ee | |
parent | 039be85c410bfb4b53cdee2083b4245e0d4e4181 (diff) |
block: Fix invalidate_cache error path for parent activation
bdrv_co_invalidate_cache() clears the BDRV_O_INACTIVE flag before
actually activating a node so that the correct permissions etc. are
taken. In case of errors, the flag must be restored so that the next
call to bdrv_co_invalidate_cache() retries activation.
Restoring the flag was missing in the error path for a failed
parent->role->activate() call. The consequence is that this attempt to
activate all images correctly fails because we still set errp, however
on the next attempt BDRV_O_INACTIVE is already clear, so we return
success without actually retrying the failed action.
An example where this is observable in practice is migration to a QEMU
instance that has a raw format block node attached to a guest device
with share-rw=off (the default) while another process holds
BLK_PERM_WRITE for the same image. In this case, all activation steps
before parent->role->activate() succeed because raw can tolerate other
writers to the image. Only the parent callback (in particular
blk_root_activate()) tries to implement the share-rw=on property and
requests exclusive write permissions. This fails when the migration
completes and correctly displays an error. However, a manual 'cont' will
incorrectly resume the VM without calling blk_root_activate() again.
This case is described in more detail in the following bug report:
https://bugzilla.redhat.com/show_bug.cgi?id=1531888
Fix this by correctly restoring the BDRV_O_INACTIVE flag in the error
path.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
-rw-r--r-- | block.c | 1 |
1 files changed, 1 insertions, 0 deletions
@@ -4697,6 +4697,7 @@ static void coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, if (parent->role->activate) { parent->role->activate(parent, &local_err); if (local_err) { + bs->open_flags |= BDRV_O_INACTIVE; error_propagate(errp, local_err); return; } |