From 480800c76969b38f13b6909eb679b23571417538 Mon Sep 17 00:00:00 2001 From: Nicholas Tsirakis Date: Tue, 11 Jun 2019 13:11:24 -0400 Subject: [PATCH] argo: warn sendv() caller when ring is full In its current state, if the destination ring is full, sendv() will requeue the message and return the rc of pending_requeue(), which will return 0 on success. This prevents the caller from distinguishing the difference between a successful write and a message that needs to be resent at a later time. Instead, capture the -EAGAIN value returned from ringbuf_insert() and *only* overwrite it if the rc of pending_requeue() is non-zero. This allows the caller to make intelligent decisions on -EAGAIN and still be alerted if the pending message fails to requeue. Signed-off-by: Nicholas Tsirakis Reviewed-by: Christopher Clark --- xen/common/argo.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/xen/common/argo.c b/xen/common/argo.c index 13052b9239..2f874a570d 100644 --- a/xen/common/argo.c +++ b/xen/common/argo.c @@ -2048,9 +2048,13 @@ sendv(struct domain *src_d, xen_argo_addr_t *src_addr, message_type, &len); if ( ret == -EAGAIN ) { + int rc; + argo_dprintk("argo_ringbuf_sendv failed, EAGAIN\n"); /* requeue to issue a notification when space is there */ - ret = pending_requeue(dst_d, ring_info, src_id.domain_id, len); + rc = pending_requeue(dst_d, ring_info, src_id.domain_id, len); + if ( rc ) + ret = rc; } spin_unlock(&ring_info->L3_lock); -- 2.30.2