From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52546) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eu0Yu-0004YO-Pe for qemu-devel@nongnu.org; Thu, 08 Mar 2018 13:46:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eu0Yp-0003J1-SG for qemu-devel@nongnu.org; Thu, 08 Mar 2018 13:46:44 -0500 From: Vladimir Sementsov-Ogievskiy Date: Thu, 8 Mar 2018 21:46:33 +0300 Message-Id: <20180308184636.178534-3-vsementsov@virtuozzo.com> In-Reply-To: <20180308184636.178534-1-vsementsov@virtuozzo.com> References: <20180308184636.178534-1-vsementsov@virtuozzo.com> Subject: [Qemu-devel] [PATCH v2 2/5] nbd/server: fix sparse read List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, qemu-block@nongnu.org Cc: pbonzini@redhat.com, eblake@redhat.com, den@openvz.org, vsementsov@virtuozzo.com In case of io error in nbd_co_send_sparse_read we should not "goto reply:", as it is fatal error and common behavior is disconnect in this case. We should not try to send client an error reply, representing channel-io error on previous try to send a reply. Fix this by handle block-status error in nbd_co_send_sparse_read, so nbd_co_send_sparse_read fails only on io error. Then just skip common "reply:" code path in nbd_trip. Signed-off-by: Vladimir Sementsov-Ogievskiy --- v2: code movement splitted to 01 remove error_report fix indent fix commit message subject line add comment to nbd_co_send_sparse_read (be free to adjust it) nbd/server.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index c406b0656d..e0de431e10 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1365,6 +1365,10 @@ static int coroutine_fn nbd_co_send_structured_error(NBDClient *client, return nbd_co_send_iov(client, iov, 1 + !!iov[1].iov_len, errp); } +/* Do sparse read and send structured reply to the client. + * Returns -errno if sending fails. bdrv_block_status_above() fail is not + * considered as an error, but reported to the client instead (as a structured + * error). */ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, uint64_t handle, uint64_t offset, @@ -1385,8 +1389,13 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, bool final; if (status < 0) { - error_setg_errno(errp, -status, "unable to check for holes"); - return status; + char *msg = g_strdup_printf("unable to check for holes: %s", + strerror(-status)); + + ret = nbd_co_send_structured_error(client, handle, -status, msg, + errp); + g_free(msg); + return ret; } assert(pnum && pnum <= size - progress); final = progress + pnum == size; @@ -1567,7 +1576,7 @@ static coroutine_fn void nbd_trip(void *opaque) request.from, req->data, request.len, &local_err); if (ret < 0) { - goto reply; + goto replied; } goto done; } @@ -1664,6 +1673,8 @@ reply: req->data, reply_data_len, &local_err); } g_free(msg); + +replied: if (ret < 0) { error_prepend(&local_err, "Failed to send reply: "); goto disconnect; -- 2.11.1