Re: [PATCH] Removed -Werror=unused-result warnings.

[Steve Dickson <SteveD@RedHat.com>]

On 03/05/2018 11:06 AM, Chuck Lever wrote:
> Hi Steve-
> 
>> On Mar 5, 2018, at 10:54 AM, Steve Dickson <steved@redhat.com> wrote:
>>
>> Signed-off-by: Steve Dickson <steved@redhat.com>
>> ---
>> support/nfs/nfs_mntent.c         | 3 ++-
>> utils/blkmapd/device-discovery.c | 6 ++++--
>> utils/mount/network.c            | 8 ++++++--
>> utils/nfsd/nfssvc.c              | 5 +++--
>> utils/statd/statd.c              | 3 ++-
>> 5 files changed, 17 insertions(+), 8 deletions(-)
>>
>> diff --git a/support/nfs/nfs_mntent.c b/support/nfs/nfs_mntent.c
>> index a2118a2..c60988a 100644
>> --- a/support/nfs/nfs_mntent.c
>> +++ b/support/nfs/nfs_mntent.c
>> @@ -150,7 +150,8 @@ nfs_addmntent (mntFILE *mfp, struct mntent *mnt) {
>> 		res = fflush(mfp->mntent_fp);
>> 		if (res < 0)
>> 			/* Avoid leaving a corrupt mtab file */
>> -			ftruncate(fileno(mfp->mntent_fp), length);
>> +			if (ftruncate(fileno(mfp->mntent_fp), length))
>> +				{/* ignore return value */};
> 
> Why not
> 
> 			(void)ftruncate(fileno(mfp->mntent_fp), length);
> 
> ?
That was the first I tried and it did not work... I still got the 
warning/error... If you have any better idea, I'm all hears! :-)

And more strangeness... I did not see these warning/errrors when I
compiled the upstream git tree on a Fedora 27 box but I do
see them when I take that tree and compile for an Fedora 28 rpm.

Thanks for cycles! 

steved.
> 
> 
>> 	}
>> 	return (res < 0) ? 1 : 0;
>> }
>> diff --git a/utils/blkmapd/device-discovery.c b/utils/blkmapd/device-discovery.c
>> index b71c949..1afc80f 100644
>> --- a/utils/blkmapd/device-discovery.c
>> +++ b/utils/blkmapd/device-discovery.c
>> @@ -504,9 +504,11 @@ int main(int argc, char **argv)
>> 			close(pidfd);
>> 			exit(1);
>> 		}
>> -		ftruncate(pidfd, 0);
>> +		if (ftruncate(pidfd, 0) < 0)
>> +			BL_LOG_WARNING("ftruncate on %s failed: m\n", PID_FILE);
>> 		sprintf(pidbuf, "%d\n", getpid());
>> -		write(pidfd, pidbuf, strlen(pidbuf));
>> +		if (write(pidfd, pidbuf, strlen(pidbuf)) != (ssize_t)strlen(pidbuf))
>> +			BL_LOG_WARNING("write on %s failed: m\n", PID_FILE);
>> 	}
>>
>> 	signal(SIGINT, sig_die);
>> diff --git a/utils/mount/network.c b/utils/mount/network.c
>> index 8d6e4c6..9a2c878 100644
>> --- a/utils/mount/network.c
>> +++ b/utils/mount/network.c
>> @@ -811,8 +811,12 @@ int start_statd(void)
>> 			switch (pid) {
>> 			case 0: /* child */
>> 				setgroups(0, NULL);
>> -				setgid(0);
>> -				setuid(0);
>> +				if (setgid(0) < 0)
>> +					nfs_error(_("%s: setgid(0) failed: %s"),
>> +						progname, strerror(errno));
>> +				if (setuid(0) < 0)
>> +					nfs_error(_("%s: setuid(0) failed: %s"),
>> +						progname, strerror(errno));
>> 				execle(START_STATD, START_STATD, NULL, envp);
>> 				exit(1);
>> 			case -1: /* error */
>> diff --git a/utils/nfsd/nfssvc.c b/utils/nfsd/nfssvc.c
>> index fc36792..7923f5d 100644
>> --- a/utils/nfsd/nfssvc.c
>> +++ b/utils/nfsd/nfssvc.c
>> @@ -68,7 +68,7 @@ nfssvc_mount_nfsdfs(char *progname)
>> 	 * mount nfsdfs when nfsd.ko is plugged in. So, ignore the return
>> 	 * code from it and just check for the "threads" file afterward.
>> 	 */
>> -	system("/bin/mount -t nfsd nfsd " NFSD_FS_DIR " >/dev/null 2>&1");
>> +	err = system("/bin/mount -t nfsd nfsd " NFSD_FS_DIR " >/dev/null 2>&1");
>>
>> 	err = stat(NFSD_THREAD_FILE, &statbuf);
>> 	if (err == 0)
>> @@ -325,7 +325,8 @@ nfssvc_set_time(const char *type, const int seconds)
>> 		/* set same value for lockd */
>> 		fd = open("/proc/sys/fs/nfs/nlm_grace_period", O_WRONLY);
>> 		if (fd >= 0) {
>> -			write(fd, nbuf, strlen(nbuf));
>> +			if (write(fd, nbuf, strlen(nbuf)) != (ssize_t)strlen(nbuf))
>> +				xlog(L_ERROR, "Unable to write nlm_grace_period : %m");
>> 			close(fd);
>> 		}
>> 	}
>> diff --git a/utils/statd/statd.c b/utils/statd/statd.c
>> index 197d853..563a272 100644
>> --- a/utils/statd/statd.c
>> +++ b/utils/statd/statd.c
>> @@ -225,7 +225,8 @@ static void set_nlm_port(char *type, int port)
>> 	fd = open(pathbuf, O_WRONLY);
>> 	if (fd < 0 && errno == ENOENT) {
>> 		/* probably module not loaded */
>> -		system("modprobe lockd");
>> +		if (system("modprobe lockd"))
>> +			{/* ignore return value */};
>> 		fd = open(pathbuf, O_WRONLY);
>> 	}
>> 	if (fd >= 0) {
>> -- 
>> 2.14.3
>>
>> --
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> 
> --
> Chuck Lever
> 
> 
>