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authorJan Kiszka <jan.kiszka@web.de>2010-02-08 10:12:27 +0000
committerDavid S. Miller <davem@davemloft.net>2010-02-16 16:01:28 -0800
commit0159d5491fef4acadd116a989b671e1cd350382f (patch)
tree2cc7d1567c18a6629ea641922880ece36ad765de
parente95ac143868752ad30d93068a6fc0b39cf3a1bf4 (diff)
CAPI: Use kref on capiminor
Install a reference counter for capiminor objects. Acquire it when obtaining a capiminor from the array during capinc_tty_open, drop it when closing the tty again. Another reference is held for the hook-up with capincci. Signed-off-by: Jan Kiszka <jan.kiszka@web.de> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/isdn/capi/capi.c37
1 files changed, 28 insertions, 9 deletions
diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index b1de0cbea69..732cdb585b2 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -83,6 +83,8 @@ struct datahandle_queue {
};
struct capiminor {
+ struct kref kref;
+
struct capincci *nccip;
unsigned int minor;
struct dentry *capifs_dentry;
@@ -223,6 +225,8 @@ static struct capiminor *capiminor_alloc(struct capi20_appl *ap, u32 ncci)
return NULL;
}
+ kref_init(&mp->kref);
+
mp->ap = ap;
mp->ncci = ncci;
mp->msgid = 0;
@@ -265,18 +269,11 @@ err_out1:
return NULL;
}
-static void capiminor_free(struct capiminor *mp)
+static void capiminor_destroy(struct kref *kref)
{
- unsigned long flags;
-
- tty_unregister_device(capinc_tty_driver, mp->minor);
-
- write_lock_irqsave(&capiminors_lock, flags);
- capiminors[mp->minor] = NULL;
- write_unlock_irqrestore(&capiminors_lock, flags);
+ struct capiminor *mp = container_of(kref, struct capiminor, kref);
kfree_skb(mp->ttyskb);
- mp->ttyskb = NULL;
skb_queue_purge(&mp->inqueue);
skb_queue_purge(&mp->outqueue);
capiminor_del_all_ack(mp);
@@ -289,11 +286,31 @@ static struct capiminor *capiminor_get(unsigned int minor)
read_lock(&capiminors_lock);
mp = capiminors[minor];
+ if (mp)
+ kref_get(&mp->kref);
read_unlock(&capiminors_lock);
return mp;
}
+static inline void capiminor_put(struct capiminor *mp)
+{
+ kref_put(&mp->kref, capiminor_destroy);
+}
+
+static void capiminor_free(struct capiminor *mp)
+{
+ unsigned long flags;
+
+ tty_unregister_device(capinc_tty_driver, mp->minor);
+
+ write_lock_irqsave(&capiminors_lock, flags);
+ capiminors[mp->minor] = NULL;
+ write_unlock_irqrestore(&capiminors_lock, flags);
+
+ capiminor_put(mp);
+}
+
/* -------- struct capincci ----------------------------------------- */
static void capincci_alloc_minor(struct capidev *cdev, struct capincci *np)
@@ -1029,6 +1046,8 @@ static void capinc_tty_close(struct tty_struct * tty, struct file * file)
#endif
if (mp->nccip == NULL)
capiminor_free(mp);
+
+ capiminor_put(mp);
}
#ifdef _DEBUG_REFCOUNT