On 2/11/20 7:24 PM, Eric Blake wrote:
If .prepare fails, we do not want to call .finalize (similar to how
if
.open fails, we do not want to call .close). However, the logic in
backend_finalize was checking on the wrong condition ('was the
connection opened' rather than 'was the connection prepared'), which
led to an assertion failure.
Simple reproducer:
$ nbdkit -U - -f --filter cache --run 'qemu-io -r -c quit $nbd' sh -
<<\EOF
> case $1 in get_size) echo oops >&2; exit 1 ;; *) exit 2 ;; esac
> EOF
nbdkit: sh[1]: error: /tmp/nbdkitshYvAQbz/inline-script.sh: oops
nbdkit: backend.c:206: backend_finalize: Assertion `h->state &
HANDLE_CONNECTED' failed.
qemu-io: can't open device nbd:unix:/tmp/nbdkit60FUTw/socket: Failed to read option
reply: Unexpected end-of-file before all bytes were read
nbdkit: nbdkit command was killed by signal 6
With this patch, the command now fails gracefully:
nbdkit: sh[1]: error: /tmp/nbdkitshie18Lp/inline-script.sh: oops
qemu-io: can't open device nbd:unix:/tmp/nbdkitqvAOlr/socket: Requested export not
available
Fixes: ffa98c8d
Signed-off-by: Eric Blake <eblake(a)redhat.com>
---
Pushing this to master and stable-1.16
I need to quit pushing things before letting 'make check' finish; this
change now makes test-reopen-retry-fail.sh hang with a different assertion:
server/backend.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/server/backend.c b/server/backend.c
index 8bfa8525..753f5cca 100644
--- a/server/backend.c
+++ b/server/backend.c
@@ -221,15 +221,13 @@ backend_finalize (struct backend *b)
if (h->state & HANDLE_FAILED)
return -1;
- if (h->handle) {
- assert (h->state & HANDLE_CONNECTED);
+ assert (h->state & HANDLE_OPEN);
this code is not always true. I'm pushing the fixup as well.
+ if (h->state & HANDLE_CONNECTED) {
if (b->finalize (b, h->handle) == -1) {
h->state |= HANDLE_FAILED;
return -1;
}
}
- else
- assert (! (h->state & HANDLE_CONNECTED));
if (b->i)
return backend_finalize (b->next);
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization:
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