[Qemu-devel] [PULL 1/6] tap: Avoid extra iterations while closing file fd

[Stefan Hajnoczi]

From: Pankaj Gupta <address@hidden>

Avoid iterations for fd 0, 1 & 2 when we are closing file fds in child process.

Signed-off-by: Pankaj Gupta <address@hidden>
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
 net/tap.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/net/tap.c b/net/tap.c
index 8847ce1..fc1b865 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -367,11 +367,8 @@ static int launch_script(const char *setup_script, const 
char *ifname, int fd)
     if (pid == 0) {
         int open_max = sysconf(_SC_OPEN_MAX), i;
 
-        for (i = 0; i < open_max; i++) {
-            if (i != STDIN_FILENO &&
-                i != STDOUT_FILENO &&
-                i != STDERR_FILENO &&
-                i != fd) {
+        for (i = 3; i < open_max; i++) {
+            if (i != fd) {
                 close(i);
             }
         }
@@ -452,11 +449,8 @@ static int net_bridge_run_helper(const char *helper, const 
char *bridge)
         char br_buf[6+IFNAMSIZ] = {0};
         char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15];
 
-        for (i = 0; i < open_max; i++) {
-            if (i != STDIN_FILENO &&
-                i != STDOUT_FILENO &&
-                i != STDERR_FILENO &&
-                i != sv[1]) {
+        for (i = 3; i < open_max; i++) {
+            if (i != sv[1]) {
                 close(i);
             }
         }
-- 
1.9.0