From 4a851614cfdbebddeb78de04ac89a39d26f25459 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@fb.com>
Date: Mon, 14 Apr 2014 10:04:21 -0600
Subject: [PATCH] Error check fcntl() calls

Add a helper to mark an fd as non-blocking, so we can check
and complain in one place.

Signed-off-by: Jens Axboe <axboe@fb.com>
---
 engines/binject.c |  7 +++----
 engines/sg.c      |  7 +++----
 fio.h             |  1 +
 libfio.c          | 16 ++++++++++++++++
 server.c          |  7 ++-----
 5 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/engines/binject.c b/engines/binject.c
index fb190620..0264d0a3 100644
--- a/engines/binject.c
+++ b/engines/binject.c
@@ -109,10 +109,9 @@ static int fio_binject_getevents(struct thread_data *td, unsigned int min,
 		/*
 		 * don't block for min events == 0
 		 */
-		if (!min) {
-			bd->fd_flags[i] = fcntl(bf->fd, F_GETFL);
-			fcntl(bf->fd, F_SETFL, bd->fd_flags[i] | O_NONBLOCK);
-		}
+		if (!min)
+			fio_set_fd_nonblocking(bf->fd, "binject");
+
 		bd->pfds[i].fd = bf->fd;
 		bd->pfds[i].events = POLLIN;
 	}
diff --git a/engines/sg.c b/engines/sg.c
index 88d91258..fcd9c413 100644
--- a/engines/sg.c
+++ b/engines/sg.c
@@ -77,10 +77,9 @@ static int fio_sgio_getevents(struct thread_data *td, unsigned int min,
 		/*
 		 * don't block for min events == 0
 		 */
-		if (!min) {
-			sd->fd_flags[i] = fcntl(f->fd, F_GETFL);
-			fcntl(f->fd, F_SETFL, sd->fd_flags[i] | O_NONBLOCK);
-		}
+		if (!min)
+			fio_set_fd_nonblocking(f->fd, "sg");
+
 		sd->pfds[i].fd = f->fd;
 		sd->pfds[i].events = POLLIN;
 	}
diff --git a/fio.h b/fio.h
index 14459134..25f6052b 100644
--- a/fio.h
+++ b/fio.h
@@ -441,6 +441,7 @@ extern char *num2str(unsigned long, int, int, int, int);
 extern int ioengine_load(struct thread_data *);
 extern int parse_dryrun(void);
 extern int fio_running_or_pending_io_threads(void);
+extern void fio_set_fd_nonblocking(int, const char *);
 
 extern uintptr_t page_mask;
 extern uintptr_t page_size;
diff --git a/libfio.c b/libfio.c
index 3fde492c..5ed8c607 100644
--- a/libfio.c
+++ b/libfio.c
@@ -27,6 +27,7 @@
 #include <signal.h>
 #include <stdint.h>
 #include <locale.h>
+#include <fcntl.h>
 
 #include "fio.h"
 #include "smalloc.h"
@@ -233,6 +234,21 @@ int fio_running_or_pending_io_threads(void)
 	return 0;
 }
 
+void fio_set_fd_nonblocking(int fd, const char *who)
+{
+	int flags;
+
+	flags = fcntl(fd, F_GETFL);
+	if (flags < 0)
+		log_err("fio: %s failed to get file flags: %s\n", who, strerror(errno));
+	else {
+		flags |= O_NONBLOCK;
+		flags = fcntl(fd, F_SETFL, flags);
+		if (flags < 0)
+			log_err("fio: %s failed to get file flags: %s\n", who, strerror(errno));
+	}
+}
+
 static int endian_check(void)
 {
 	union {
diff --git a/server.c b/server.c
index ab3bece1..1c4c494a 100644
--- a/server.c
+++ b/server.c
@@ -4,7 +4,6 @@
 #include <unistd.h>
 #include <limits.h>
 #include <errno.h>
-#include <fcntl.h>
 #include <sys/poll.h>
 #include <sys/types.h>
 #include <sys/wait.h>
@@ -843,14 +842,12 @@ static int accept_loop(int listen_sk)
 	struct sockaddr_in6 addr6;
 	socklen_t len = use_ipv6 ? sizeof(addr6) : sizeof(addr);
 	struct pollfd pfd;
-	int ret = 0, sk, flags, exitval = 0;
+	int ret = 0, sk, exitval = 0;
 	FLIST_HEAD(conn_list);
 
 	dprint(FD_NET, "server enter accept loop\n");
 
-	flags = fcntl(listen_sk, F_GETFL);
-	flags |= O_NONBLOCK;
-	fcntl(listen_sk, F_SETFL, flags);
+	fio_set_fd_nonblocking(listen_sk, "server");
 
 	while (!exit_backend) {
 		const char *from;
-- 
2.25.1