[PATCH] uml: fix mcast network driver error handling

printk clears the host errno (I verified this in debugging and it's reasonable
enough, given that it ends via a write call on some fd, especially since
printk() goes on /dev/tty0 which is often the host stdout).  So save errno
earlier.  There's no reason to change the printk calls to use -err rather than
errno - the assignment can't clear errno.

And in the first failure path, we used to return 0 too (and this time more
clearly), which is totally wrong.  0 is a success fd, which is then registered
and gives a "registering fd twice" warning.

Finally, fix up some whitespace.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/um/drivers/mcast_user.c b/arch/um/drivers/mcast_user.c
index 5db136e..afe85bf 100644 (file)
--- a/arch/um/drivers/mcast_user.c
+++ b/arch/um/drivers/mcast_user.c
@@ -54,7 +54,7 @@ static int mcast_open(void *data)
        struct mcast_data *pri = data;
        struct sockaddr_in *sin = pri->mcast_addr;
        struct ip_mreq mreq;
-       int fd, yes = 1, err = 0;
+       int fd, yes = 1, err = -EINVAL;
 
 
        if ((sin->sin_addr.s_addr == 0) || (sin->sin_port == 0))
@@ -63,40 +63,40 @@ static int mcast_open(void *data)
        fd = socket(AF_INET, SOCK_DGRAM, 0);
 
        if (fd < 0){
+               err = -errno;
                printk("mcast_open : data socket failed, errno = %d\n", 
                       errno);
-               err = -errno;
                goto out;
        }
 
        if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
+               err = -errno;
                printk("mcast_open: SO_REUSEADDR failed, errno = %d\n",
                        errno);
-               err = -errno;
                goto out_close;
        }
 
        /* set ttl according to config */
        if (setsockopt(fd, SOL_IP, IP_MULTICAST_TTL, &pri->ttl,
                       sizeof(pri->ttl)) < 0) {
+               err = -errno;
                printk("mcast_open: IP_MULTICAST_TTL failed, error = %d\n",
                        errno);
-               err = -errno;
                goto out_close;
        }
 
        /* set LOOP, so data does get fed back to local sockets */
        if (setsockopt(fd, SOL_IP, IP_MULTICAST_LOOP, &yes, sizeof(yes)) < 0) {
+               err = -errno;
                printk("mcast_open: IP_MULTICAST_LOOP failed, error = %d\n",
                        errno);
-               err = -errno;
                goto out_close;
        }
 
        /* bind socket to mcast address */
        if (bind(fd, (struct sockaddr *) sin, sizeof(*sin)) < 0) {
-               printk("mcast_open : data bind failed, errno = %d\n", errno);
                err = -errno;
+               printk("mcast_open : data bind failed, errno = %d\n", errno);
                goto out_close;
        }               
        
@@ -105,22 +105,22 @@ static int mcast_open(void *data)
        mreq.imr_interface.s_addr = 0;
        if (setsockopt(fd, SOL_IP, IP_ADD_MEMBERSHIP, 
                       &mreq, sizeof(mreq)) < 0) {
+               err = -errno;
                printk("mcast_open: IP_ADD_MEMBERSHIP failed, error = %d\n",
                        errno);
                printk("There appears not to be a multicast-capable network "
                       "interface on the host.\n");
                printk("eth0 should be configured in order to use the "
                       "multicast transport.\n");
-               err = -errno;
-                goto out_close;
+               goto out_close;
        }
 
        return fd;
 
  out_close:
-        os_close_file(fd);
+       os_close_file(fd);
  out:
-        return err;
+       return err;
 }
 
 static void mcast_close(int fd, void *data)