From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Alan D. Brunelle" <Alan.Brunelle@hp.com>
Date: Tue, 03 Feb 2009 22:30:49 +0000
Subject: Question: blktrace server mode & orderly shut down
Message-Id: <4988C599.6070909@hp.com>
List-Id: <linux-btrace.vger.kernel.org>
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To: linux-btrace@vger.kernel.org

According to the recv(2) man page:

The return value will be 0 when the peer has performed an orderly
shutdown.

Yet the code in read_data_net and net_get_header both attempt to re-read
from a socket that will _never_ have data. (I hit this problem today on
blktrace2 - I've got orderly shut downs in place.)

Does this pseudo-patch break something?

diff --git a/blktrace.c b/blktrace.c
index c55b491..9ef7313 100644
--- a/blktrace.c
+++ b/blktrace.c
@@ -550,7 +550,7 @@ static int read_data_net(struct thread_information
*tip, voi
                ret = recv(nc->in_fd, buf, bytes_left, MSG_WAITALL);

                if (!ret)
-                       continue;
+                       return 0;
                else if (ret < 0) {
                        if (errno != EAGAIN) {
                                perror(tip->fn);
@@ -1466,8 +1466,7 @@ static int net_get_header(struct net_connection *nc,
                        usleep(1000);
                        continue;
                } else if (!ret) {
-                       usleep(1000);
-                       continue;
+                       return 0;
                } else {
                        p += ret;
                        bytes_left -= ret;