qcow2: Use QcowCache

[qemu.git] / os-posix.c

diff --git a/os-posix.c b/os-posix.c
index 804e20c189454ce09155fee99d645cd21b72d920..38c29d1afe42ff3b2e7fc28f938e5798a2551053 100644 (file)
--- a/os-posix.c
+++ b/os-posix.c
@@ -28,6 +28,8 @@
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+/*needed for MAP_POPULATE before including qemu-options.h */
+#include <sys/mman.h>
 #include <pwd.h>
 #include <libgen.h>
 
@@ -41,6 +43,10 @@
 #include <sys/prctl.h>
 #endif
 
+#ifdef CONFIG_EVENTFD
+#include <sys/eventfd.h>
+#endif
+
 static struct passwd *user_pwd;
 static const char *chroot_dir;
 static int daemonize;
@@ -108,7 +114,7 @@ char *os_find_datadir(const char *argv0)
         size_t len = sizeof(buf) - 1;
 
         *buf = '\0';
-        if (!sysctl(mib, sizeof(mib)/sizeof(*mib), buf, &len, NULL, 0) &&
+        if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
             *buf) {
             buf[sizeof(buf) - 1] = '\0';
             p = buf;
@@ -327,3 +333,52 @@ void os_set_line_buffering(void)
 {
     setvbuf(stdout, NULL, _IOLBF, 0);
 }
+
+/*
+ * Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.
+ */
+int qemu_eventfd(int fds[2])
+{
+#ifdef CONFIG_EVENTFD
+    int ret;
+
+    ret = eventfd(0, 0);
+    if (ret >= 0) {
+        fds[0] = ret;
+        qemu_set_cloexec(ret);
+        if ((fds[1] = dup(ret)) == -1) {
+            close(ret);
+            return -1;
+        }
+        qemu_set_cloexec(fds[1]);
+        return 0;
+    }
+
+    if (errno != ENOSYS) {
+        return -1;
+    }
+#endif
+
+    return qemu_pipe(fds);
+}
+
+int qemu_create_pidfile(const char *filename)
+{
+    char buffer[128];
+    int len;
+    int fd;
+
+    fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
+    if (fd == -1) {
+        return -1;
+    }
+    if (lockf(fd, F_TLOCK, 0) == -1) {
+        return -1;
+    }
+    len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());
+    if (write(fd, buffer, len) != len) {
+        return -1;
+    }
+
+    return 0;
+}