From: "Manish Katiyar" Subject: [PATCH] logsave : Avoid unnecessary backgrounding of logsave in case of failures Date: Tue, 7 Oct 2008 23:14:11 +0530 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: mkatiyar@gmail.com To: ext4 , "Theodore Tso" Return-path: Received: from ti-out-0910.google.com ([209.85.142.190]:29704 "EHLO ti-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752961AbYJGRoN (ORCPT ); Tue, 7 Oct 2008 13:44:13 -0400 Received: by ti-out-0910.google.com with SMTP id b6so2012393tic.23 for ; Tue, 07 Oct 2008 10:44:11 -0700 (PDT) Content-Disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi Ted, I am not sure why we wan't to background the logsave and keep retrying opening the fd in case of failures. But there may be situations when we will never be able to succeed and thus create unnecessary process. For example invoking it /home/mkatiyar/sbin> ./logsave /testfile ls as a normal user will never succeed. Below patch adds some of the error conditions where we can just avoid it. Signed-off-by : Manish Katiyar --- misc/logsave.c | 19 +++++++++++++++++-- 1 files changed, 17 insertions(+), 2 deletions(-) diff --git a/misc/logsave.c b/misc/logsave.c index f0011f8..77a0a16 100644 --- a/misc/logsave.c +++ b/misc/logsave.c @@ -203,6 +203,17 @@ static int copy_from_stdin(void) return 0; } +static void should_background(int err, int *nobackground) { + switch (err) { + case EPERM: + case EACCES: + *nobackground = err; + break; + default : + *nobackground = 0; + } + return ; +} int main(int argc, char **argv) @@ -211,7 +222,7 @@ int main(int argc, char **argv) char *outfn, **cpp; int openflags = O_CREAT|O_WRONLY|O_TRUNC; int send_flag = SEND_LOG; - int do_stdin; + int do_stdin, nobackground = 0; time_t t; while ((c = getopt(argc, argv, "+asv")) != EOF) { @@ -237,6 +248,8 @@ int main(int argc, char **argv) argc -= optind; outfd = open(outfn, openflags, 0644); + if (outfd < 0) + should_background(errno, &nobackground); do_stdin = !strcmp(argv[0], "-"); send_output("Log of ", 0, send_flag); @@ -263,7 +276,7 @@ int main(int argc, char **argv) send_output(ctime(&t), 0, send_flag); send_output("----------------\n", 0, send_flag); - if (outbuf) { + if (!nobackground) { pid = fork(); if (pid < 0) { perror("fork"); @@ -282,6 +295,8 @@ int main(int argc, char **argv) } write(outfd, outbuf, outbufsize); free(outbuf); + } else { + printf("Unable to save log to %s : %s\n", outfn, strerror(nobackground)); } close(outfd); -- 1.5.4.3 Thanks - Manish