Pull cpu-hotplug into release branch

[powerpc.git] / arch / um / os-Linux / umid.c

diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
index ecf107a..362db05 100644 (file)
--- a/arch/um/os-Linux/umid.c
+++ b/arch/um/os-Linux/umid.c
@@ -120,7 +120,8 @@ static int not_dead_yet(char *dir)
 
        dead = 0;
        fd = open(file, O_RDONLY);
-       if(fd < 0){
+       if(fd < 0) {
+               fd = -errno;
                if(fd != -ENOENT){
                        printk("not_dead_yet : couldn't open pid file '%s', "
                               "err = %d\n", file, -fd);
@@ -130,9 +131,13 @@ static int not_dead_yet(char *dir)
 
        err = 0;
        n = read(fd, pid, sizeof(pid));
-       if(n <= 0){
+       if(n < 0){
+               printk("not_dead_yet : couldn't read pid file '%s', "
+                      "err = %d\n", file, errno);
+               goto out_close;
+       } else if(n == 0){
                printk("not_dead_yet : couldn't read pid file '%s', "
-                      "err = %d\n", file, -n);
+                      "0-byte read\n", file);
                goto out_close;
        }
 
@@ -143,8 +148,10 @@ static int not_dead_yet(char *dir)
                goto out_close;
        }
 
-       if((kill(p, 0) == 0) || (errno != ESRCH))
+       if((kill(p, 0) == 0) || (errno != ESRCH)){
+               printk("umid \"%s\" is already in use by pid %d\n", umid, p);
                return 1;
+       }
 
        err = actually_do_remove(dir);
        if(err)
@@ -153,9 +160,9 @@ static int not_dead_yet(char *dir)
 
        return err;
 
- out_close:
+out_close:
        close(fd);
- out:
+out:
        return 0;
 }
 
@@ -171,14 +178,14 @@ static void __init create_pid_file(void)
        fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0644);
        if(fd < 0){
                printk("Open of machine pid file \"%s\" failed: %s\n",
-                      file, strerror(-fd));
+                      file, strerror(errno));
                return;
        }
 
        snprintf(pid, sizeof(pid), "%d\n", getpid());
        n = write(fd, pid, strlen(pid));
        if(n != strlen(pid))
-               printk("Write of pid file failed - err = %d\n", -n);
+               printk("Write of pid file failed - err = %d\n", errno);
 
        close(fd);
 }
@@ -234,33 +241,44 @@ int __init make_umid(void)
        err = mkdir(tmp, 0777);
        if(err < 0){
                err = -errno;
-               if(errno != EEXIST)
+               if(err != -EEXIST)
                        goto err;
 
-               if(not_dead_yet(tmp) < 0)
+               /* 1   -> this umid is already in use
+                * < 0 -> we couldn't remove the umid directory
+                * In either case, we can't use this umid, so return -EEXIST.
+                */
+               if(not_dead_yet(tmp) != 0)
                        goto err;
 
                err = mkdir(tmp, 0777);
        }
-       if(err < 0){
-               printk("Failed to create '%s' - err = %d\n", umid, err);
-               goto err_rmdir;
+       if(err){
+               err = -errno;
+               printk("Failed to create '%s' - err = %d\n", umid, -errno);
+               goto err;
        }
 
        umid_setup = 1;
 
        create_pid_file();
 
-       return 0;
-
- err_rmdir:
-       rmdir(tmp);
+       err = 0;
  err:
        return err;
 }
 
 static int __init make_umid_init(void)
 {
+       if(!make_umid())
+               return 0;
+
+       /* If initializing with the given umid failed, then try again with
+        * a random one.
+        */
+       printk("Failed to initialize umid \"%s\", trying with a random umid\n",
+              umid);
+       *umid = '\0';
        make_umid();
 
        return 0;