[PATCH] nfs-utils: Removed a number of warn_unused_result warnings

[Steve Dickson <SteveD@redhat.com>]

Here is a patch that removes a number of annoying 'warn_unused_result' 
warnings that have recently popped up in Fedora builds.

Its probably a good thing to log these failures, but there is 
really not much we can do about them so I've logged the failures
as warnings... 

This exercise also illuminates all the different ways there
are to call syslog()... We really need to looking into creating
exactly one way for all apps in nfs-utils to log messages to
syslog().. Yeah.. Yeah... I know... Patches are welcome! ;-)

steved.
  

In recent Fedora builds, the '-D _FORTIFY_SOURCE=2' compile
flag has been set. This cause warnings to be generated when 
return values from reads/writes (and other calls) are not 
checked. The patch address those warnings. 

Signed-off-by: Steve Dickson <steved@redhat.com>
------------------------------------------

diff -up nfs-utils-1.1.5/support/nfs/cacheio.c.orig nfs-utils-1.1.5/support/nfs/cacheio.c
--- nfs-utils-1.1.5/support/nfs/cacheio.c.orig	2009-03-05 06:42:56.000000000 -0500
+++ nfs-utils-1.1.5/support/nfs/cacheio.c	2009-03-23 09:41:54.000000000 -0400
@@ -24,6 +24,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <time.h>
+#include <errno.h>
 
 void qword_add(char **bpp, int *lp, char *str)
 {
@@ -125,7 +126,10 @@ void qword_print(FILE *f, char *str)
 	char *bp = qword_buf;
 	int len = sizeof(qword_buf);
 	qword_add(&bp, &len, str);
-	fwrite(qword_buf, bp-qword_buf, 1, f);
+	if (fwrite(qword_buf, bp-qword_buf, 1, f) != 1) {
+		xlog_warn("qword_print: fwrite failed: errno %d (%s)",
+			errno, strerror(errno));
+	}
 }
 
 void qword_printhex(FILE *f, char *str, int slen)
@@ -133,7 +137,10 @@ void qword_printhex(FILE *f, char *str, 
 	char *bp = qword_buf;
 	int len = sizeof(qword_buf);
 	qword_addhex(&bp, &len, str, slen);
-	fwrite(qword_buf, bp-qword_buf, 1, f);
+	if (fwrite(qword_buf, bp-qword_buf, 1, f) != 1) {
+		xlog_warn("qword_printhex: fwrite failed: errno %d (%s)",
+			errno, strerror(errno));
+	}
 }
 
 void qword_printint(FILE *f, int num)
@@ -318,7 +325,10 @@ cache_flush(int force)
 		sprintf(path, "/proc/net/rpc/%s/flush", cachelist[c]);
 		fd = open(path, O_RDWR);
 		if (fd >= 0) {
-			write(fd, stime, strlen(stime));
+			if (write(fd, stime, strlen(stime)) != strlen(stime)) {
+				xlog_warn("Writing to '%s' failed: errno %d (%s)",
+				path, errno, strerror(errno));
+			}
 			close(fd);
 		}
 	}
diff -up nfs-utils-1.1.5/tools/locktest/testlk.c.orig nfs-utils-1.1.5/tools/locktest/testlk.c
--- nfs-utils-1.1.5/tools/locktest/testlk.c.orig	2009-03-05 06:42:56.000000000 -0500
+++ nfs-utils-1.1.5/tools/locktest/testlk.c	2009-03-23 08:33:10.000000000 -0400
@@ -81,7 +81,7 @@ main(int argc, char **argv)
 		if (fl.l_type == F_UNLCK) {
 			printf("%s: no conflicting lock\n", fname);
 		} else {
-			printf("%s: conflicting lock by %d on (%ld;%ld)\n",
+			printf("%s: conflicting lock by %d on (%lld;%lld)\n",
 				fname, fl.l_pid, fl.l_start, fl.l_len);
 		}
 		return 0;
diff -up nfs-utils-1.1.5/utils/gssd/svcgssd.c.orig nfs-utils-1.1.5/utils/gssd/svcgssd.c
--- nfs-utils-1.1.5/utils/gssd/svcgssd.c.orig	2009-03-05 06:42:56.000000000 -0500
+++ nfs-utils-1.1.5/utils/gssd/svcgssd.c	2009-03-23 08:49:49.000000000 -0400
@@ -132,7 +132,11 @@ release_parent(void)
 	int status;
 
 	if (pipefds[1] > 0) {
-		write(pipefds[1], &status, 1);
+		if (write(pipefds[1], &status, 1) != 1) {
+			printerr(1, 
+				"WARN: writing to parent pipe failed: errno %d (%s)\n",
+				errno, strerror(errno));
+		}
 		close(pipefds[1]);
 		pipefds[1] = -1;
 	}
diff -up nfs-utils-1.1.5/utils/idmapd/idmapd.c.orig nfs-utils-1.1.5/utils/idmapd/idmapd.c
--- nfs-utils-1.1.5/utils/idmapd/idmapd.c.orig	2009-03-05 06:42:56.000000000 -0500
+++ nfs-utils-1.1.5/utils/idmapd/idmapd.c	2009-03-23 08:53:44.000000000 -0400
@@ -169,7 +169,10 @@ flush_nfsd_cache(char *path, time_t now)
 	fd = open(path, O_RDWR);
 	if (fd == -1)
 		return -1;
-	write(fd, stime, strlen(stime));
+	if (write(fd, stime, strlen(stime)) != strlen(stime)) {
+		errx(1, "Flushing nfsd cache failed: errno %d (%s)",
+			errno, strerror(errno));
+	}
 	close(fd);
 	return 0;
 }
@@ -988,7 +991,10 @@ release_parent(void)
 	int status;
 
 	if (pipefds[1] > 0) {
-		write(pipefds[1], &status, 1);
+		if (write(pipefds[1], &status, 1) != 1) {
+			err(1, "Writing to parent pipe failed: errno %d (%s)\n",
+				errno, strerror(errno));
+		}
 		close(pipefds[1]);
 		pipefds[1] = -1;
 	}
diff -up nfs-utils-1.1.5/utils/mount/fstab.c.orig nfs-utils-1.1.5/utils/mount/fstab.c
--- nfs-utils-1.1.5/utils/mount/fstab.c.orig	2009-03-05 06:42:56.000000000 -0500
+++ nfs-utils-1.1.5/utils/mount/fstab.c	2009-03-23 08:44:42.000000000 -0400
@@ -546,8 +546,12 @@ update_mtab (const char *dir, struct mnt
 	   * from the present mtab before renaming.
 	   */
 	    struct stat sbuf;
-	    if (stat (MOUNTED, &sbuf) == 0)
-		chown (MOUNTED_TEMP, sbuf.st_uid, sbuf.st_gid);
+	    if (stat (MOUNTED, &sbuf) == 0) {
+			if (chown (MOUNTED_TEMP, sbuf.st_uid, sbuf.st_gid) < 0) {
+				nfs_error(_("%s: error changing owner of %s: %s"),
+					progname, MOUNTED_TEMP, strerror (errno));
+			}
+		}
 	}
 
 	/* rename mtemp to mtab */
diff -up nfs-utils-1.1.5/utils/statd/monitor.c.orig nfs-utils-1.1.5/utils/statd/monitor.c
--- nfs-utils-1.1.5/utils/statd/monitor.c.orig	2009-03-05 06:42:56.000000000 -0500
+++ nfs-utils-1.1.5/utils/statd/monitor.c	2009-03-23 09:25:20.000000000 -0400
@@ -204,7 +204,10 @@ sm_mon_1_svc(struct mon *argp, struct sv
 			e += sprintf(e, "%02x", 0xff & (argp->priv[i]));
 		if (e+1-buf != LINELEN) abort();
 		e += sprintf(e, " %s %s\n", mon_name, my_name);
-		write(fd, buf, e-buf);
+		if (write(fd, buf, e-buf) != (e-buf)) {
+			note(N_WARNING, "writing to %s failed: errno %d (%s)",
+				path, errno, strerror(errno));
+		}
 	}
 
 	free(path);
diff -up nfs-utils-1.1.5/utils/statd/sm-notify.c.orig nfs-utils-1.1.5/utils/statd/sm-notify.c
--- nfs-utils-1.1.5/utils/statd/sm-notify.c.orig	2009-03-23 08:26:22.000000000 -0400
+++ nfs-utils-1.1.5/utils/statd/sm-notify.c	2009-03-23 08:58:36.000000000 -0400
@@ -784,7 +784,10 @@ static int record_pid(void)
 	fd = open("/var/run/sm-notify.pid", O_CREAT|O_EXCL|O_WRONLY, 0600);
 	if (fd < 0)
 		return 0;
-	write(fd, pid, strlen(pid));
+	if (write(fd, pid, strlen(pid)) != strlen(pid))  {
+		nsm_log(LOG_WARNING, "Writing to pid file failed: errno %d(%s)",
+			errno, strerror(errno));
+	}
 	close(fd);
 	return 1;
 }
@@ -820,12 +823,16 @@ static void drop_privs(void)
 static void set_kernel_nsm_state(int state)
 {
 	int fd;
+	const char *file = "/proc/sys/fs/nfs/nsm_local_state";
 
-	fd = open("/proc/sys/fs/nfs/nsm_local_state",O_WRONLY);
+	fd = open(file ,O_WRONLY);
 	if (fd >= 0) {
 		char buf[20];
 		snprintf(buf, sizeof(buf), "%d", state);
-		write(fd, buf, strlen(buf));
+		if (write(fd, buf, strlen(buf)) != strlen(buf)) {
+			nsm_log(LOG_WARNING, "Writing to '%s' failed: errno %d (%s)",
+				file, errno, strerror(errno));
+		}
 		close(fd);
 	}
 }
diff -up nfs-utils-1.1.5/utils/statd/statd.c.orig nfs-utils-1.1.5/utils/statd/statd.c
--- nfs-utils-1.1.5/utils/statd/statd.c.orig	2009-03-05 06:42:56.000000000 -0500
+++ nfs-utils-1.1.5/utils/statd/statd.c	2009-03-23 09:21:27.000000000 -0400
@@ -179,14 +179,20 @@ static void create_pidfile(void)
 		    pidfile, strerror(errno));
 	fprintf(fp, "%d\n", getpid());
 	pidfd = dup(fileno(fp));
-	if (fclose(fp) < 0)
-		note(N_WARNING, "Flushing pid file failed.\n");
+	if (fclose(fp) < 0) {
+		note(N_WARNING, "Flushing pid file failed: errno %d (%s)\n",
+			errno, strerror(errno));
+	}
 }
 
 static void truncate_pidfile(void)
 {
-	if (pidfd >= 0)
-		ftruncate(pidfd, 0);
+	if (pidfd >= 0) {
+		if (ftruncate(pidfd, 0) < 0) {
+			note(N_WARNING, "truncating pid file failed: errno %d (%s)\n",
+				errno, strerror(errno));
+		}
+	}
 }
 
 static void drop_privs(void)
@@ -207,9 +213,12 @@ static void drop_privs(void)
 	/* better chown the pid file before dropping, as if it
 	 * if over nfs we might loose access
 	 */
-	if (pidfd >= 0)
-		fchown(pidfd, st.st_uid, st.st_gid);
-
+	if (pidfd >= 0) {
+		if (fchown(pidfd, st.st_uid, st.st_gid) < 0) {
+			note(N_ERROR, "Unable to change owner of %s: %d (%s)",
+					SM_DIR, strerror (errno));
+		}
+	}
 	setgroups(0, NULL);
 	if (setgid(st.st_gid) == -1
 	    || setuid(st.st_uid) == -1) {
@@ -495,7 +504,10 @@ int main (int argc, char **argv)
 	/* If we got this far, we have successfully started, so notify parent */
 	if (pipefds[1] > 0) {
 		status = 0;
-		write(pipefds[1], &status, 1);
+		if (write(pipefds[1], &status, 1) != 1) {
+			note(N_WARNING, "writing to parent pipe failed: errno %d (%s)\n",
+				errno, strerror(errno));
+		}
 		close(pipefds[1]);
 		pipefds[1] = -1;
 	}
@@ -534,17 +546,23 @@ static void
 load_state_number(void)
 {
 	int fd;
+	const char *file = "/proc/sys/fs/nfs/nsm_local_state";
 
 	if ((fd = open(SM_STAT_PATH, O_RDONLY)) == -1)
 		return;
 
-	read(fd, &MY_STATE, sizeof(MY_STATE));
+	if (read(fd, &MY_STATE, sizeof(MY_STATE)) != sizeof(MY_STATE)) {
+		note(N_WARNING, "Unable to read state from '%s': errno %d (%s)",
+				SM_STAT_PATH, errno, strerror(errno));
+	}
 	close(fd);
-	fd = open("/proc/sys/fs/nfs/nsm_local_state",O_WRONLY);
+	fd = open(file, O_WRONLY);
 	if (fd >= 0) {
 		char buf[20];
 		snprintf(buf, sizeof(buf), "%d", MY_STATE);
-		write(fd, buf, strlen(buf));
+		if (write(fd, buf, strlen(buf)) != strlen(buf))
+			note(N_WARNING, "Writing to '%s' failed: errno %d (%s)",
+				file, errno, strerror(errno));
 		close(fd);
 	}