Re: [PATCH v2 for-7.1 9/9] nbd: document what is protected by the CoMutexes

[Vladimir Sementsov-Ogievskiy]

14.04.2022 20:57, Paolo Bonzini wrote:

Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
  block/nbd.c | 8 +++++++-
  1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/block/nbd.c b/block/nbd.c
index 31c684772e..d0d94b40bd 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -81,12 +81,18 @@ typedef struct BDRVNBDState {
      NBDClientRequest requests[MAX_NBD_REQUESTS];
      QEMUTimer *reconnect_delay_timer;

+ /* Protects sending data on the socket. */

      CoMutex send_mutex;
+
+    /*
+     * Protects receiving reply headers from the socket, as well as the
+     * fields reply and requests[].receiving

I think, worth noting, that s->reply is used without mutex after 
nbd_receive_replies() success and till setting s->reply.handle to 0 in 
nbd_co_receive_one_chunk()..

Should "s->reply.handle = 0" be done under mutex as well? And may be, in same 
critical section as nbd_recv_coroutines_wake() ?

+     */
      CoMutex receive_mutex;
+    NBDReply reply;

QEMUTimer *open_timer; - NBDReply reply;

      BlockDriverState *bs;

/* Connection parameters */

--
Best regards,
Vladimir