diff options
| -rw-r--r-- | hw/9pfs/9p.c | 18 | ||||
| -rw-r--r-- | hw/9pfs/trace-events | 1 |
2 files changed, 19 insertions, 0 deletions
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 364c7cb..e88bb50 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -630,6 +630,24 @@ static void coroutine_fn pdu_complete(V9fsPDU *pdu, ssize_t len) V9fsState *s = pdu->s; int ret; + /* + * The 9p spec requires that successfully cancelled pdus receive no reply. + * Sending a reply would confuse clients because they would + * assume that any EINTR is the actual result of the operation, + * rather than a consequence of the cancellation. However, if + * the operation completed (succesfully or with an error other + * than caused be cancellation), we do send out that reply, both + * for efficiency and to avoid confusing the rest of the state machine + * that assumes passing a non-error here will mean a successful + * transmission of the reply. + */ + bool discard = pdu->cancelled && len == -EINTR; + if (discard) { + trace_v9fs_rcancel(pdu->tag, pdu->id); + pdu->size = 0; + goto out_notify; + } + if (len < 0) { int err = -len; len = 7; diff --git a/hw/9pfs/trace-events b/hw/9pfs/trace-events index 08a4abf..1aee350 100644 --- a/hw/9pfs/trace-events +++ b/hw/9pfs/trace-events @@ -1,6 +1,7 @@ # See docs/devel/tracing.txt for syntax documentation. # hw/9pfs/virtio-9p.c +v9fs_rcancel(uint16_t tag, uint8_t id) "tag %d id %d" v9fs_rerror(uint16_t tag, uint8_t id, int err) "tag %d id %d err %d" v9fs_version(uint16_t tag, uint8_t id, int32_t msize, char* version) "tag %d id %d msize %d version %s" v9fs_version_return(uint16_t tag, uint8_t id, int32_t msize, char* version) "tag %d id %d msize %d version %s" |