Merge branch 'core/xen' into x86/urgent

[pandora-kernel.git] / drivers / net / ppp_generic.c

diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
index 06b4482..7b2728b 100644 (file)
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -250,6 +250,7 @@ static int ppp_connect_channel(struct channel *pch, int unit);
 static int ppp_disconnect_channel(struct channel *pch);
 static void ppp_destroy_channel(struct channel *pch);
 static int unit_get(struct idr *p, void *ptr);
+static int unit_set(struct idr *p, void *ptr, int n);
 static void unit_put(struct idr *p, int n);
 static void *unit_find(struct idr *p, int n);
 
@@ -2432,11 +2433,18 @@ ppp_create_interface(int unit, int *retp)
        } else {
                if (unit_find(&ppp_units_idr, unit))
                        goto out2; /* unit already exists */
-               else {
-                       /* darn, someone is cheating us? */
-                       *retp = -EINVAL;
+               /*
+                * if caller need a specified unit number
+                * lets try to satisfy him, otherwise --
+                * he should better ask us for new unit number
+                *
+                * NOTE: yes I know that returning EEXIST it's not
+                * fair but at least pppd will ask us to allocate
+                * new unit in this case so user is happy :)
+                */
+               unit = unit_set(&ppp_units_idr, ppp, unit);
+               if (unit < 0)
                        goto out2;
-               }
        }
 
        /* Initialize the new ppp unit */
@@ -2677,14 +2685,37 @@ static void __exit ppp_cleanup(void)
  * by holding all_ppp_mutex
  */
 
+/* associate pointer with specified number */
+static int unit_set(struct idr *p, void *ptr, int n)
+{
+       int unit, err;
+
+again:
+       if (!idr_pre_get(p, GFP_KERNEL)) {
+               printk(KERN_ERR "PPP: No free memory for idr\n");
+               return -ENOMEM;
+       }
+
+       err = idr_get_new_above(p, ptr, n, &unit);
+       if (err == -EAGAIN)
+               goto again;
+
+       if (unit != n) {
+               idr_remove(p, unit);
+               return -EINVAL;
+       }
+
+       return unit;
+}
+
 /* get new free unit number and associate pointer with it */
 static int unit_get(struct idr *p, void *ptr)
 {
        int unit, err;
 
 again:
-       if (idr_pre_get(p, GFP_KERNEL) == 0) {
-               printk(KERN_ERR "Out of memory expanding drawable idr\n");
+       if (!idr_pre_get(p, GFP_KERNEL)) {
+               printk(KERN_ERR "PPP: No free memory for idr\n");
                return -ENOMEM;
        }