From a12a712a7dfbd2e2f4882ef2c90a9b2162166dd7 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 14 Mar 2017 12:11:56 +0100 Subject: [PATCH] nbd-client: fix handling of hungup connections After the switch to reading replies in a coroutine, nothing is reentering pending receive coroutines if the connection hangs. Move nbd_recv_coroutines_enter_all to the reply read coroutine, which is the place where hangups are detected. nbd_teardown_connection can simply wait for the reply read coroutine to detect the hangup and clean up after itself. This wouldn't be enough though because nbd_receive_reply returns 0 (rather than -EPIPE or similar) when reading from a hung connection. Fix the return value check in nbd_read_reply_entry. This fixes qemu-iotests 083. Reported-by: Max Reitz Signed-off-by: Paolo Bonzini Message-id: 20170314111157.14464-1-pbonzini@redhat.com Reviewed-by: Max Reitz Signed-off-by: Max Reitz --- block/nbd-client.c | 12 ++++++------ nbd/client.c | 2 +- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/block/nbd-client.c b/block/nbd-client.c index 0dc12c2d67..1e2952fdae 100644 --- a/block/nbd-client.c +++ b/block/nbd-client.c @@ -33,17 +33,15 @@ #define HANDLE_TO_INDEX(bs, handle) ((handle) ^ ((uint64_t)(intptr_t)bs)) #define INDEX_TO_HANDLE(bs, index) ((index) ^ ((uint64_t)(intptr_t)bs)) -static void nbd_recv_coroutines_enter_all(BlockDriverState *bs) +static void nbd_recv_coroutines_enter_all(NBDClientSession *s) { - NBDClientSession *s = nbd_get_client_session(bs); int i; for (i = 0; i < MAX_NBD_REQUESTS; i++) { if (s->recv_coroutine[i]) { - qemu_coroutine_enter(s->recv_coroutine[i]); + aio_co_wake(s->recv_coroutine[i]); } } - BDRV_POLL_WHILE(bs, s->read_reply_co); } static void nbd_teardown_connection(BlockDriverState *bs) @@ -58,7 +56,7 @@ static void nbd_teardown_connection(BlockDriverState *bs) qio_channel_shutdown(client->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); - nbd_recv_coroutines_enter_all(bs); + BDRV_POLL_WHILE(bs, client->read_reply_co); nbd_client_detach_aio_context(bs); object_unref(OBJECT(client->sioc)); @@ -76,7 +74,7 @@ static coroutine_fn void nbd_read_reply_entry(void *opaque) for (;;) { assert(s->reply.handle == 0); ret = nbd_receive_reply(s->ioc, &s->reply); - if (ret < 0) { + if (ret <= 0) { break; } @@ -103,6 +101,8 @@ static coroutine_fn void nbd_read_reply_entry(void *opaque) aio_co_wake(s->recv_coroutine[i]); qemu_coroutine_yield(); } + + nbd_recv_coroutines_enter_all(s); s->read_reply_co = NULL; } diff --git a/nbd/client.c b/nbd/client.c index 3dc2564cd0..a58fb02cb4 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -812,6 +812,6 @@ ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply) LOG("invalid magic (got 0x%" PRIx32 ")", magic); return -EINVAL; } - return 0; + return sizeof(buf); }