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From: "Alan D. Brunelle" <Alan.Brunelle@hp.com>
To: linux-btrace@vger.kernel.org
Subject: Question: blktrace server mode & orderly shut down
Date: Tue, 03 Feb 2009 22:30:49 +0000	[thread overview]
Message-ID: <4988C599.6070909@hp.com> (raw)

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;


             reply	other threads:[~2009-02-03 22:30 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-02-03 22:30 Alan D. Brunelle [this message]
2009-02-06  8:03 ` Question: blktrace server mode & orderly shut down Jens Axboe
2009-02-06 11:36 ` Alan D. Brunelle

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