diff options
| -rw-r--r-- | drivers/net/ppp_generic.c | 43 |
1 files changed, 37 insertions, 6 deletions
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c index 06b448285eb..7b2728b8f1b 100644 --- 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; } |