1 files changed, 574 insertions, 629 deletions

diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index 65bf91e16a4..ee5837522f5 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -23,16 +23,13 @@
 #include <linux/smp_lock.h>
 #include <linux/timer.h>
 #include <linux/wait.h>
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
 #include <linux/tty.h>
-#ifdef CONFIG_PPP
 #include <linux/netdevice.h>
 #include <linux/ppp_defs.h>
 #include <linux/if_ppp.h>
-#endif /* CONFIG_PPP */
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
 #include <linux/skbuff.h>
 #include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/poll.h>
 #include <linux/capi.h>
 #include <linux/kernelcapi.h>
@@ -41,35 +38,29 @@
 #include <linux/moduleparam.h>
 #include <linux/isdn/capiutil.h>
 #include <linux/isdn/capicmd.h>
-#if defined(CONFIG_ISDN_CAPI_CAPIFS) || defined(CONFIG_ISDN_CAPI_CAPIFS_MODULE)
-#include "capifs.h"
-#endif
 
-static char *revision = "$Revision: 1.1.2.7 $";
+#include "capifs.h"
 
 MODULE_DESCRIPTION("CAPI4Linux: Userspace /dev/capi20 interface");
 MODULE_AUTHOR("Carsten Paeth");
 MODULE_LICENSE("GPL");
 
-#undef _DEBUG_REFCOUNT		/* alloc/free and open/close debug */
 #undef _DEBUG_TTYFUNCS		/* call to tty_driver */
 #undef _DEBUG_DATAFLOW		/* data flow */
 
 /* -------- driver information -------------------------------------- */
 
 static struct class *capi_class;
-
 static int capi_major = 68;		/* allocated */
+
+module_param_named(major, capi_major, uint, 0);
+
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-#define CAPINC_NR_PORTS	32
+#define CAPINC_NR_PORTS		32
 #define CAPINC_MAX_PORTS	256
-static int capi_ttymajor = 191;
+
 static int capi_ttyminors = CAPINC_NR_PORTS;
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
 
-module_param_named(major, capi_major, uint, 0);
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-module_param_named(ttymajor, capi_ttymajor, uint, 0);
 module_param_named(ttyminors, capi_ttyminors, uint, 0);
 #endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
 
@@ -83,53 +74,43 @@ module_param_named(ttyminors, capi_ttyminors, uint, 0);
 
 struct capidev;
 struct capincci;
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
 struct capiminor;
 
-struct datahandle_queue {
+struct ackqueue_entry {
 	struct list_head	list;
 	u16			datahandle;
 };
 
 struct capiminor {
-	struct list_head list;
-	struct capincci  *nccip;
+	struct kref kref;
+
 	unsigned int      minor;
+	struct dentry *capifs_dentry;
 
-	struct capi20_appl *ap;
-	u32		 ncci;
-	u16		 datahandle;
-	u16		 msgid;
+	struct capi20_appl	*ap;
+	u32			ncci;
+	atomic_t		datahandle;
+	atomic_t		msgid;
 
-	struct tty_struct *tty;
+	struct tty_port port;
 	int                ttyinstop;
 	int                ttyoutstop;
-	struct sk_buff    *ttyskb;
-	atomic_t           ttyopencount;
 
-	struct sk_buff_head inqueue;
-	int                 inbytes;
-	struct sk_buff_head outqueue;
-	int                 outbytes;
+	struct sk_buff_head	inqueue;
+
+	struct sk_buff_head	outqueue;
+	int			outbytes;
+	struct sk_buff		*outskb;
+	spinlock_t		outlock;
 
 	/* transmit path */
 	struct list_head ackqueue;
 	int nack;
 	spinlock_t ackqlock;
 };
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
-
-/* FIXME: The following lock is a sledgehammer-workaround to a
- * locking issue with the capiminor (and maybe other) data structure(s).
- * Access to this data is done in a racy way and crashes the machine with
- * a FritzCard DSL driver; sooner or later. This is a workaround
- * which trades scalability vs stability, so it doesn't crash the kernel anymore.
- * The correct (and scalable) fix for the issue seems to require
- * an API change to the drivers... . */
-static DEFINE_SPINLOCK(workaround_lock);
 
 struct capincci {
-	struct capincci *next;
+	struct list_head list;
 	u32		 ncci;
 	struct capidev	*cdev;
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
@@ -146,28 +127,28 @@ struct capidev {
 	struct sk_buff_head recvqueue;
 	wait_queue_head_t recvwait;
 
-	struct capincci *nccis;
+	struct list_head nccis;
 
-	struct mutex ncci_list_mtx;
+	struct mutex lock;
 };
 
 /* -------- global variables ---------------------------------------- */
 
-static DEFINE_RWLOCK(capidev_list_lock);
+static DEFINE_MUTEX(capidev_list_lock);
 static LIST_HEAD(capidev_list);
 
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-static DEFINE_RWLOCK(capiminor_list_lock);
-static LIST_HEAD(capiminor_list);
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
 
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
+static DEFINE_SPINLOCK(capiminors_lock);
+static struct capiminor **capiminors;
+
+static struct tty_driver *capinc_tty_driver;
+
 /* -------- datahandles --------------------------------------------- */
 
-static int capincci_add_ack(struct capiminor *mp, u16 datahandle)
+static int capiminor_add_ack(struct capiminor *mp, u16 datahandle)
 {
-	struct datahandle_queue *n;
-	unsigned long flags;
+	struct ackqueue_entry *n;
 
 	n = kmalloc(sizeof(*n), GFP_ATOMIC);
 	if (unlikely(!n)) {
@@ -176,253 +157,246 @@ static int capincci_add_ack(struct capiminor *mp, u16 datahandle)
 	}
 	n->datahandle = datahandle;
 	INIT_LIST_HEAD(&n->list);
-	spin_lock_irqsave(&mp->ackqlock, flags);
+	spin_lock_bh(&mp->ackqlock);
 	list_add_tail(&n->list, &mp->ackqueue);
 	mp->nack++;
-	spin_unlock_irqrestore(&mp->ackqlock, flags);
+	spin_unlock_bh(&mp->ackqlock);
 	return 0;
 }
 
 static int capiminor_del_ack(struct capiminor *mp, u16 datahandle)
 {
-	struct datahandle_queue *p, *tmp;
-	unsigned long flags;
+	struct ackqueue_entry *p, *tmp;
 
-	spin_lock_irqsave(&mp->ackqlock, flags);
+	spin_lock_bh(&mp->ackqlock);
 	list_for_each_entry_safe(p, tmp, &mp->ackqueue, list) {
  		if (p->datahandle == datahandle) {
 			list_del(&p->list);
-			kfree(p);
 			mp->nack--;
-			spin_unlock_irqrestore(&mp->ackqlock, flags);
+			spin_unlock_bh(&mp->ackqlock);
+			kfree(p);
 			return 0;
 		}
 	}
-	spin_unlock_irqrestore(&mp->ackqlock, flags);
+	spin_unlock_bh(&mp->ackqlock);
 	return -1;
 }
 
 static void capiminor_del_all_ack(struct capiminor *mp)
 {
-	struct datahandle_queue *p, *tmp;
-	unsigned long flags;
+	struct ackqueue_entry *p, *tmp;
 
-	spin_lock_irqsave(&mp->ackqlock, flags);
 	list_for_each_entry_safe(p, tmp, &mp->ackqueue, list) {
 		list_del(&p->list);
 		kfree(p);
 		mp->nack--;
 	}
-	spin_unlock_irqrestore(&mp->ackqlock, flags);
 }
 
 
 /* -------- struct capiminor ---------------------------------------- */
 
+static const struct tty_port_operations capiminor_port_ops; /* we have none */
+
 static struct capiminor *capiminor_alloc(struct capi20_appl *ap, u32 ncci)
 {
-	struct capiminor *mp, *p;
-	unsigned int minor = 0;
-	unsigned long flags;
+	struct capiminor *mp;
+	struct device *dev;
+	unsigned int minor;
 
-	mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
+	mp = kzalloc(sizeof(*mp), GFP_KERNEL);
   	if (!mp) {
   		printk(KERN_ERR "capi: can't alloc capiminor\n");
 		return NULL;
 	}
 
+	kref_init(&mp->kref);
+
 	mp->ap = ap;
 	mp->ncci = ncci;
-	mp->msgid = 0;
-	atomic_set(&mp->ttyopencount,0);
 	INIT_LIST_HEAD(&mp->ackqueue);
 	spin_lock_init(&mp->ackqlock);
 
 	skb_queue_head_init(&mp->inqueue);
 	skb_queue_head_init(&mp->outqueue);
+	spin_lock_init(&mp->outlock);
 
-	/* Allocate the least unused minor number.
-	 */
-	write_lock_irqsave(&capiminor_list_lock, flags);
-	if (list_empty(&capiminor_list))
-		list_add(&mp->list, &capiminor_list);
-	else {
-		list_for_each_entry(p, &capiminor_list, list) {
-			if (p->minor > minor)
-				break;
-			minor++;
-		}
-		
-		if (minor < capi_ttyminors) {
-			mp->minor = minor;
-			list_add(&mp->list, p->list.prev);
+	tty_port_init(&mp->port);
+	mp->port.ops = &capiminor_port_ops;
+
+	/* Allocate the least unused minor number. */
+	spin_lock(&capiminors_lock);
+	for (minor = 0; minor < capi_ttyminors; minor++)
+		if (!capiminors[minor]) {
+			capiminors[minor] = mp;
+			break;
 		}
-	}
-		write_unlock_irqrestore(&capiminor_list_lock, flags);
+	spin_unlock(&capiminors_lock);
 
-	if (!(minor < capi_ttyminors)) {
+	if (minor == capi_ttyminors) {
 		printk(KERN_NOTICE "capi: out of minors\n");
-			kfree(mp);
-		return NULL;
+		goto err_out1;
 	}
 
+	mp->minor = minor;
+
+	dev = tty_register_device(capinc_tty_driver, minor, NULL);
+	if (IS_ERR(dev))
+		goto err_out2;
+
 	return mp;
+
+err_out2:
+	spin_lock(&capiminors_lock);
+	capiminors[minor] = NULL;
+	spin_unlock(&capiminors_lock);
+
+err_out1:
+	kfree(mp);
+	return NULL;
 }
 
-static void capiminor_free(struct capiminor *mp)
+static void capiminor_destroy(struct kref *kref)
 {
-	unsigned long flags;
-
-	write_lock_irqsave(&capiminor_list_lock, flags);
-	list_del(&mp->list);
-	write_unlock_irqrestore(&capiminor_list_lock, flags);
+	struct capiminor *mp = container_of(kref, struct capiminor, kref);
 
-	kfree_skb(mp->ttyskb);
-	mp->ttyskb = NULL;
+	kfree_skb(mp->outskb);
 	skb_queue_purge(&mp->inqueue);
 	skb_queue_purge(&mp->outqueue);
 	capiminor_del_all_ack(mp);
 	kfree(mp);
 }
 
-static struct capiminor *capiminor_find(unsigned int minor)
+static struct capiminor *capiminor_get(unsigned int minor)
 {
-	struct list_head *l;
-	struct capiminor *p = NULL;
+	struct capiminor *mp;
 
-	read_lock(&capiminor_list_lock);
-	list_for_each(l, &capiminor_list) {
-		p = list_entry(l, struct capiminor, list);
-		if (p->minor == minor)
-			break;
-	}
-	read_unlock(&capiminor_list_lock);
-	if (l == &capiminor_list)
-		return NULL;
+	spin_lock(&capiminors_lock);
+	mp = capiminors[minor];
+	if (mp)
+		kref_get(&mp->kref);
+	spin_unlock(&capiminors_lock);
 
-	return p;
+	return mp;
+}
+
+static inline void capiminor_put(struct capiminor *mp)
+{
+	kref_put(&mp->kref, capiminor_destroy);
+}
+
+static void capiminor_free(struct capiminor *mp)
+{
+	tty_unregister_device(capinc_tty_driver, mp->minor);
+
+	spin_lock(&capiminors_lock);
+	capiminors[mp->minor] = NULL;
+	spin_unlock(&capiminors_lock);
+
+	capiminor_put(mp);
 }
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
 
 /* -------- struct capincci ----------------------------------------- */
 
-static struct capincci *capincci_alloc(struct capidev *cdev, u32 ncci)
+static void capincci_alloc_minor(struct capidev *cdev, struct capincci *np)
 {
-	struct capincci *np, **pp;
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-	struct capiminor *mp = NULL;
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
+	struct capiminor *mp;
+	dev_t device;
 
-	np = kzalloc(sizeof(*np), GFP_ATOMIC);
-	if (!np)
-		return NULL;
-	np->ncci = ncci;
-	np->cdev = cdev;
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-	mp = NULL;
-	if (cdev->userflags & CAPIFLAG_HIGHJACKING)
-		mp = np->minorp = capiminor_alloc(&cdev->ap, ncci);
+	if (!(cdev->userflags & CAPIFLAG_HIGHJACKING))
+		return;
+
+	mp = np->minorp = capiminor_alloc(&cdev->ap, np->ncci);
 	if (mp) {
-		mp->nccip = np;
-#ifdef _DEBUG_REFCOUNT
-		printk(KERN_DEBUG "set mp->nccip\n");
-#endif
-#if defined(CONFIG_ISDN_CAPI_CAPIFS) || defined(CONFIG_ISDN_CAPI_CAPIFS_MODULE)
-		capifs_new_ncci(mp->minor, MKDEV(capi_ttymajor, mp->minor));
-#endif
+		device = MKDEV(capinc_tty_driver->major, mp->minor);
+		mp->capifs_dentry = capifs_new_ncci(mp->minor, device);
 	}
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
-	for (pp=&cdev->nccis; *pp; pp = &(*pp)->next)
-		;
-	*pp = np;
-        return np;
 }
 
-static void capincci_free(struct capidev *cdev, u32 ncci)
+static void capincci_free_minor(struct capincci *np)
 {
-	struct capincci *np, **pp;
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-	struct capiminor *mp;
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
+	struct capiminor *mp = np->minorp;
+	struct tty_struct *tty;
 
-	pp=&cdev->nccis;
-	while (*pp) {
-		np = *pp;
-		if (ncci == 0xffffffff || np->ncci == ncci) {
-			*pp = (*pp)->next;
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-			if ((mp = np->minorp) != NULL) {
-#if defined(CONFIG_ISDN_CAPI_CAPIFS) || defined(CONFIG_ISDN_CAPI_CAPIFS_MODULE)
-				capifs_free_ncci(mp->minor);
-#endif
-				if (mp->tty) {
-					mp->nccip = NULL;
-#ifdef _DEBUG_REFCOUNT
-					printk(KERN_DEBUG "reset mp->nccip\n");
-#endif
-					tty_hangup(mp->tty);
-				} else {
-					capiminor_free(mp);
-				}
-			}
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
-			kfree(np);
-			if (*pp == NULL) return;
-		} else {
-			pp = &(*pp)->next;
+	if (mp) {
+		capifs_free_ncci(mp->capifs_dentry);
+
+		tty = tty_port_tty_get(&mp->port);
+		if (tty) {
+			tty_vhangup(tty);
+			tty_kref_put(tty);
 		}
+
+		capiminor_free(mp);
 	}
 }
 
-static struct capincci *capincci_find(struct capidev *cdev, u32 ncci)
+static inline unsigned int capincci_minor_opencount(struct capincci *np)
 {
-	struct capincci *p;
+	struct capiminor *mp = np->minorp;
+	unsigned int count = 0;
+	struct tty_struct *tty;
 
-	for (p=cdev->nccis; p ; p = p->next) {
-		if (p->ncci == ncci)
-			break;
+	if (mp) {
+		tty = tty_port_tty_get(&mp->port);
+		if (tty) {
+			count = tty->count;
+			tty_kref_put(tty);
+		}
 	}
-	return p;
+	return count;
 }
 
-/* -------- struct capidev ------------------------------------------ */
+#else /* !CONFIG_ISDN_CAPI_MIDDLEWARE */
+
+static inline void
+capincci_alloc_minor(struct capidev *cdev, struct capincci *np) { }
+static inline void capincci_free_minor(struct capincci *np) { }
 
-static struct capidev *capidev_alloc(void)
+static inline unsigned int capincci_minor_opencount(struct capincci *np)
 {
-	struct capidev *cdev;
-	unsigned long flags;
+	return 0;
+}
 
-	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
-	if (!cdev)
+#endif /* !CONFIG_ISDN_CAPI_MIDDLEWARE */
+
+static struct capincci *capincci_alloc(struct capidev *cdev, u32 ncci)
+{
+	struct capincci *np;
+
+	np = kzalloc(sizeof(*np), GFP_KERNEL);
+	if (!np)
 		return NULL;
+	np->ncci = ncci;
+	np->cdev = cdev;
 
-	mutex_init(&cdev->ncci_list_mtx);
-	skb_queue_head_init(&cdev->recvqueue);
-	init_waitqueue_head(&cdev->recvwait);
-	write_lock_irqsave(&capidev_list_lock, flags);
-	list_add_tail(&cdev->list, &capidev_list);
-	write_unlock_irqrestore(&capidev_list_lock, flags);
-        return cdev;
+	capincci_alloc_minor(cdev, np);
+
+	list_add_tail(&np->list, &cdev->nccis);
+
+	return np;
 }
 
-static void capidev_free(struct capidev *cdev)
+static void capincci_free(struct capidev *cdev, u32 ncci)
 {
-	unsigned long flags;
+	struct capincci *np, *tmp;
 
-	if (cdev->ap.applid) {
-		capi20_release(&cdev->ap);
-		cdev->ap.applid = 0;
-	}
-	skb_queue_purge(&cdev->recvqueue);
+	list_for_each_entry_safe(np, tmp, &cdev->nccis, list)
+		if (ncci == 0xffffffff || np->ncci == ncci) {
+			capincci_free_minor(np);
+			list_del(&np->list);
+			kfree(np);
+		}
+}
 
-	mutex_lock(&cdev->ncci_list_mtx);
-	capincci_free(cdev, 0xffffffff);
-	mutex_unlock(&cdev->ncci_list_mtx);
+static struct capincci *capincci_find(struct capidev *cdev, u32 ncci)
+{
+	struct capincci *np;
 
-	write_lock_irqsave(&capidev_list_lock, flags);
-	list_del(&cdev->list);
-	write_unlock_irqrestore(&capidev_list_lock, flags);
-	kfree(cdev);
+	list_for_each_entry(np, &cdev->nccis, list)
+		if (np->ncci == ncci)
+			return np;
+	return NULL;
 }
 
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
@@ -432,7 +406,7 @@ static struct sk_buff *
 gen_data_b3_resp_for(struct capiminor *mp, struct sk_buff *skb)
 {
 	struct sk_buff *nskb;
-	nskb = alloc_skb(CAPI_DATA_B3_RESP_LEN, GFP_ATOMIC);
+	nskb = alloc_skb(CAPI_DATA_B3_RESP_LEN, GFP_KERNEL);
 	if (nskb) {
 		u16 datahandle = CAPIMSG_U16(skb->data,CAPIMSG_BASELEN+4+4+2);
 		unsigned char *s = skb_put(nskb, CAPI_DATA_B3_RESP_LEN);
@@ -440,7 +414,7 @@ gen_data_b3_resp_for(struct capiminor *mp, struct sk_buff *skb)
 		capimsg_setu16(s, 2, mp->ap->applid);
 		capimsg_setu8 (s, 4, CAPI_DATA_B3);
 		capimsg_setu8 (s, 5, CAPI_RESP);
-		capimsg_setu16(s, 6, mp->msgid++);
+		capimsg_setu16(s, 6, atomic_inc_return(&mp->msgid));
 		capimsg_setu32(s, 8, mp->ncci);
 		capimsg_setu16(s, 12, datahandle);
 	}
@@ -449,122 +423,156 @@ gen_data_b3_resp_for(struct capiminor *mp, struct sk_buff *skb)
 
 static int handle_recv_skb(struct capiminor *mp, struct sk_buff *skb)
 {
+	unsigned int datalen = skb->len - CAPIMSG_LEN(skb->data);
+	struct tty_struct *tty;
 	struct sk_buff *nskb;
-	int datalen;
 	u16 errcode, datahandle;
 	struct tty_ldisc *ld;
-	
-	datalen = skb->len - CAPIMSG_LEN(skb->data);
-	if (mp->tty == NULL)
-	{
+	int ret = -1;
+
+	tty = tty_port_tty_get(&mp->port);
+	if (!tty) {
 #ifdef _DEBUG_DATAFLOW
 		printk(KERN_DEBUG "capi: currently no receiver\n");
 #endif
 		return -1;
 	}
 	
-	ld = tty_ldisc_ref(mp->tty);
-	if (ld == NULL)
-		return -1;
+	ld = tty_ldisc_ref(tty);
+	if (!ld) {
+		/* fatal error, do not requeue */
+		ret = 0;
+		kfree_skb(skb);
+		goto deref_tty;
+	}
+
 	if (ld->ops->receive_buf == NULL) {
 #if defined(_DEBUG_DATAFLOW) || defined(_DEBUG_TTYFUNCS)
 		printk(KERN_DEBUG "capi: ldisc has no receive_buf function\n");
 #endif
-		goto bad;
+		/* fatal error, do not requeue */
+		goto free_skb;
 	}
 	if (mp->ttyinstop) {
 #if defined(_DEBUG_DATAFLOW) || defined(_DEBUG_TTYFUNCS)
 		printk(KERN_DEBUG "capi: recv tty throttled\n");
 #endif
-		goto bad;
+		goto deref_ldisc;
 	}
-	if (mp->tty->receive_room < datalen) {
+
+	if (tty->receive_room < datalen) {
 #if defined(_DEBUG_DATAFLOW) || defined(_DEBUG_TTYFUNCS)
 		printk(KERN_DEBUG "capi: no room in tty\n");
 #endif
-		goto bad;
+		goto deref_ldisc;
 	}
-	if ((nskb = gen_data_b3_resp_for(mp, skb)) == NULL) {
+
+	nskb = gen_data_b3_resp_for(mp, skb);
+	if (!nskb) {
 		printk(KERN_ERR "capi: gen_data_b3_resp failed\n");
-		goto bad;
+		goto deref_ldisc;
 	}
-	datahandle = CAPIMSG_U16(skb->data,CAPIMSG_BASELEN+4);
+
+	datahandle = CAPIMSG_U16(skb->data, CAPIMSG_BASELEN + 4);
+
 	errcode = capi20_put_message(mp->ap, nskb);
-	if (errcode != CAPI_NOERROR) {
+
+	if (errcode == CAPI_NOERROR) {
+		skb_pull(skb, CAPIMSG_LEN(skb->data));
+#ifdef _DEBUG_DATAFLOW
+		printk(KERN_DEBUG "capi: DATA_B3_RESP %u len=%d => ldisc\n",
+					datahandle, skb->len);
+#endif
+		ld->ops->receive_buf(tty, skb->data, NULL, skb->len);
+	} else {
 		printk(KERN_ERR "capi: send DATA_B3_RESP failed=%x\n",
 				errcode);
 		kfree_skb(nskb);
-		goto bad;
+
+		if (errcode == CAPI_SENDQUEUEFULL)
+			goto deref_ldisc;
 	}
-	(void)skb_pull(skb, CAPIMSG_LEN(skb->data));
-#ifdef _DEBUG_DATAFLOW
-	printk(KERN_DEBUG "capi: DATA_B3_RESP %u len=%d => ldisc\n",
-				datahandle, skb->len);
-#endif
-	ld->ops->receive_buf(mp->tty, skb->data, NULL, skb->len);
+
+free_skb:
+	ret = 0;
 	kfree_skb(skb);
+
+deref_ldisc:
 	tty_ldisc_deref(ld);
-	return 0;
-bad:
-	tty_ldisc_deref(ld);
-	return -1;
+
+deref_tty:
+	tty_kref_put(tty);
+	return ret;
 }
 
 static void handle_minor_recv(struct capiminor *mp)
 {
 	struct sk_buff *skb;
-	while ((skb = skb_dequeue(&mp->inqueue)) != NULL) {
-		unsigned int len = skb->len;
-		mp->inbytes -= len;
+
+	while ((skb = skb_dequeue(&mp->inqueue)) != NULL)
 		if (handle_recv_skb(mp, skb) < 0) {
 			skb_queue_head(&mp->inqueue, skb);
-			mp->inbytes += len;
 			return;
 		}
-	}
 }
 
-static int handle_minor_send(struct capiminor *mp)
+static void handle_minor_send(struct capiminor *mp)
 {
+	struct tty_struct *tty;
 	struct sk_buff *skb;
 	u16 len;
-	int count = 0;
 	u16 errcode;
 	u16 datahandle;
 
-	if (mp->tty && mp->ttyoutstop) {
+	tty = tty_port_tty_get(&mp->port);
+	if (!tty)
+		return;
+
+	if (mp->ttyoutstop) {
 #if defined(_DEBUG_DATAFLOW) || defined(_DEBUG_TTYFUNCS)
 		printk(KERN_DEBUG "capi: send: tty stopped\n");
 #endif
-		return 0;
+		tty_kref_put(tty);
+		return;
 	}
 
-	while ((skb = skb_dequeue(&mp->outqueue)) != NULL) {
-		datahandle = mp->datahandle;
+	while (1) {
+		spin_lock_bh(&mp->outlock);
+		skb = __skb_dequeue(&mp->outqueue);
+		if (!skb) {
+			spin_unlock_bh(&mp->outlock);
+			break;
+		}
 		len = (u16)skb->len;
+		mp->outbytes -= len;
+		spin_unlock_bh(&mp->outlock);
+
+		datahandle = atomic_inc_return(&mp->datahandle);
 		skb_push(skb, CAPI_DATA_B3_REQ_LEN);
 		memset(skb->data, 0, CAPI_DATA_B3_REQ_LEN);
 		capimsg_setu16(skb->data, 0, CAPI_DATA_B3_REQ_LEN);
 		capimsg_setu16(skb->data, 2, mp->ap->applid);
 		capimsg_setu8 (skb->data, 4, CAPI_DATA_B3);
 		capimsg_setu8 (skb->data, 5, CAPI_REQ);
-		capimsg_setu16(skb->data, 6, mp->msgid++);
+		capimsg_setu16(skb->data, 6, atomic_inc_return(&mp->msgid));
 		capimsg_setu32(skb->data, 8, mp->ncci);	/* NCCI */
 		capimsg_setu32(skb->data, 12, (u32)(long)skb->data);/* Data32 */
 		capimsg_setu16(skb->data, 16, len);	/* Data length */
 		capimsg_setu16(skb->data, 18, datahandle);
 		capimsg_setu16(skb->data, 20, 0);	/* Flags */
 
-		if (capincci_add_ack(mp, datahandle) < 0) {
+		if (capiminor_add_ack(mp, datahandle) < 0) {
 			skb_pull(skb, CAPI_DATA_B3_REQ_LEN);
-			skb_queue_head(&mp->outqueue, skb);
-			return count;
+
+			spin_lock_bh(&mp->outlock);
+			__skb_queue_head(&mp->outqueue, skb);
+			mp->outbytes += len;
+			spin_unlock_bh(&mp->outlock);
+
+			break;
 		}
 		errcode = capi20_put_message(mp->ap, skb);
 		if (errcode == CAPI_NOERROR) {
-			mp->datahandle++;
-			count++;
-			mp->outbytes -= len;
 #ifdef _DEBUG_DATAFLOW
 			printk(KERN_DEBUG "capi: DATA_B3_REQ %u len=%u\n",
 							datahandle, len);
@@ -575,16 +583,20 @@ static int handle_minor_send(struct capiminor *mp)
 
 		if (errcode == CAPI_SENDQUEUEFULL) {
 			skb_pull(skb, CAPI_DATA_B3_REQ_LEN);
-			skb_queue_head(&mp->outqueue, skb);
+
+			spin_lock_bh(&mp->outlock);
+			__skb_queue_head(&mp->outqueue, skb);
+			mp->outbytes += len;
+			spin_unlock_bh(&mp->outlock);
+
 			break;
 		}
 
 		/* ups, drop packet */
 		printk(KERN_ERR "capi: put_message = %x\n", errcode);
-		mp->outbytes -= len;
 		kfree_skb(skb);
 	}
-	return count;
+	tty_kref_put(tty);
 }
 
 #endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
@@ -594,65 +606,56 @@ static void capi_recv_message(struct capi20_appl *ap, struct sk_buff *skb)
 {
 	struct capidev *cdev = ap->private;
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
+	struct tty_struct *tty;
 	struct capiminor *mp;
 	u16 datahandle;
 #endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
 	struct capincci *np;
-	u32 ncci;
-	unsigned long flags;
+
+	mutex_lock(&cdev->lock);
 
 	if (CAPIMSG_CMD(skb->data) == CAPI_CONNECT_B3_CONF) {
 		u16 info = CAPIMSG_U16(skb->data, 12); // Info field
-		if ((info & 0xff00) == 0) {
-			mutex_lock(&cdev->ncci_list_mtx);
+		if ((info & 0xff00) == 0)
 			capincci_alloc(cdev, CAPIMSG_NCCI(skb->data));
-			mutex_unlock(&cdev->ncci_list_mtx);
-		}
 	}
-	if (CAPIMSG_CMD(skb->data) == CAPI_CONNECT_B3_IND) {
-		mutex_lock(&cdev->ncci_list_mtx);
+	if (CAPIMSG_CMD(skb->data) == CAPI_CONNECT_B3_IND)
 		capincci_alloc(cdev, CAPIMSG_NCCI(skb->data));
-		mutex_unlock(&cdev->ncci_list_mtx);
-	}
-	spin_lock_irqsave(&workaround_lock, flags);
+
 	if (CAPIMSG_COMMAND(skb->data) != CAPI_DATA_B3) {
 		skb_queue_tail(&cdev->recvqueue, skb);
 		wake_up_interruptible(&cdev->recvwait);
-		spin_unlock_irqrestore(&workaround_lock, flags);
-		return;
+		goto unlock_out;
 	}
-	ncci = CAPIMSG_CONTROL(skb->data);
-	for (np = cdev->nccis; np && np->ncci != ncci; np = np->next)
-		;
+
+	np = capincci_find(cdev, CAPIMSG_CONTROL(skb->data));
 	if (!np) {
 		printk(KERN_ERR "BUG: capi_signal: ncci not found\n");
 		skb_queue_tail(&cdev->recvqueue, skb);
 		wake_up_interruptible(&cdev->recvwait);
-		spin_unlock_irqrestore(&workaround_lock, flags);
-		return;
+		goto unlock_out;
 	}
+
 #ifndef CONFIG_ISDN_CAPI_MIDDLEWARE
 	skb_queue_tail(&cdev->recvqueue, skb);
 	wake_up_interruptible(&cdev->recvwait);
+
 #else /* CONFIG_ISDN_CAPI_MIDDLEWARE */
+
 	mp = np->minorp;
 	if (!mp) {
 		skb_queue_tail(&cdev->recvqueue, skb);
 		wake_up_interruptible(&cdev->recvwait);
-		spin_unlock_irqrestore(&workaround_lock, flags);
-		return;
+		goto unlock_out;
 	}
-
-
 	if (CAPIMSG_SUBCOMMAND(skb->data) == CAPI_IND) {
-		
 		datahandle = CAPIMSG_U16(skb->data, CAPIMSG_BASELEN+4+4+2);
 #ifdef _DEBUG_DATAFLOW
 		printk(KERN_DEBUG "capi_signal: DATA_B3_IND %u len=%d\n",
 				datahandle, skb->len-CAPIMSG_LEN(skb->data));
 #endif
 		skb_queue_tail(&mp->inqueue, skb);
-		mp->inbytes += skb->len;
+
 		handle_minor_recv(mp);
 
 	} else if (CAPIMSG_SUBCOMMAND(skb->data) == CAPI_CONF) {
@@ -664,10 +667,13 @@ static void capi_recv_message(struct capi20_appl *ap, struct sk_buff *skb)
 				CAPIMSG_U16(skb->data, CAPIMSG_BASELEN+4+2));
 #endif
 		kfree_skb(skb);
-		(void)capiminor_del_ack(mp, datahandle);
-		if (mp->tty)
-			tty_wakeup(mp->tty);
-		(void)handle_minor_send(mp);
+		capiminor_del_ack(mp, datahandle);
+		tty = tty_port_tty_get(&mp->port);
+		if (tty) {
+			tty_wakeup(tty);
+			tty_kref_put(tty);
+		}
+		handle_minor_send(mp);
 
 	} else {
 		/* ups, let capi application handle it :-) */
@@ -675,7 +681,9 @@ static void capi_recv_message(struct capi20_appl *ap, struct sk_buff *skb)
 		wake_up_interruptible(&cdev->recvwait);
 	}
 #endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
-	spin_unlock_irqrestore(&workaround_lock, flags);
+
+unlock_out:
+	mutex_unlock(&cdev->lock);
 }
 
 /* -------- file_operations for capidev ----------------------------- */
@@ -686,24 +694,19 @@ capi_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 	struct capidev *cdev = (struct capidev *)file->private_data;
 	struct sk_buff *skb;
 	size_t copied;
+	int err;
 
 	if (!cdev->ap.applid)
 		return -ENODEV;
 
-	if ((skb = skb_dequeue(&cdev->recvqueue)) == NULL) {
-
+	skb = skb_dequeue(&cdev->recvqueue);
+	if (!skb) {
 		if (file->f_flags & O_NONBLOCK)
 			return -EAGAIN;
-
-		for (;;) {
-			interruptible_sleep_on(&cdev->recvwait);
-			if ((skb = skb_dequeue(&cdev->recvqueue)) != NULL)
-				break;
-			if (signal_pending(current))
-				break;
-		}
-		if (skb == NULL)
-			return -ERESTARTNOHAND;
+		err = wait_event_interruptible(cdev->recvwait,
+				(skb = skb_dequeue(&cdev->recvqueue)));
+		if (err)
+			return err;
 	}
 	if (skb->len > count) {
 		skb_queue_head(&cdev->recvqueue, skb);
@@ -753,9 +756,9 @@ capi_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos
 	CAPIMSG_SETAPPID(skb->data, cdev->ap.applid);
 
 	if (CAPIMSG_CMD(skb->data) == CAPI_DISCONNECT_B3_RESP) {
-		mutex_lock(&cdev->ncci_list_mtx);
+		mutex_lock(&cdev->lock);
 		capincci_free(cdev, CAPIMSG_NCCI(skb->data));
-		mutex_unlock(&cdev->ncci_list_mtx);
+		mutex_unlock(&cdev->lock);
 	}
 
 	cdev->errcode = capi20_put_message(&cdev->ap, skb);
@@ -788,30 +791,35 @@ capi_ioctl(struct inode *inode, struct file *file,
 	   unsigned int cmd, unsigned long arg)
 {
 	struct capidev *cdev = file->private_data;
-	struct capi20_appl *ap = &cdev->ap;
 	capi_ioctl_struct data;
 	int retval = -EINVAL;
 	void __user *argp = (void __user *)arg;
 
 	switch (cmd) {
 	case CAPI_REGISTER:
-		{
-			if (ap->applid)
-				return -EEXIST;
+		mutex_lock(&cdev->lock);
 
-			if (copy_from_user(&cdev->ap.rparam, argp,
-					   sizeof(struct capi_register_params)))
-				return -EFAULT;
-			
-			cdev->ap.private = cdev;
-			cdev->ap.recv_message = capi_recv_message;
-			cdev->errcode = capi20_register(ap);
-			if (cdev->errcode) {
-				ap->applid = 0;
-				return -EIO;
-			}
+		if (cdev->ap.applid) {
+			retval = -EEXIST;
+			goto register_out;
+		}
+		if (copy_from_user(&cdev->ap.rparam, argp,
+				   sizeof(struct capi_register_params))) {
+			retval = -EFAULT;
+			goto register_out;
+		}
+		cdev->ap.private = cdev;
+		cdev->ap.recv_message = capi_recv_message;
+		cdev->errcode = capi20_register(&cdev->ap);
+		retval = (int)cdev->ap.applid;
+		if (cdev->errcode) {
+			cdev->ap.applid = 0;
+			retval = -EIO;
 		}
-		return (int)ap->applid;
+
+register_out:
+		mutex_unlock(&cdev->lock);
+		return retval;
 
 	case CAPI_GET_VERSION:
 		{
@@ -910,101 +918,104 @@ capi_ioctl(struct inode *inode, struct file *file,
 		return 0;
 
 	case CAPI_SET_FLAGS:
-	case CAPI_CLR_FLAGS:
-		{
-			unsigned userflags;
-			if (copy_from_user(&userflags, argp,
-					   sizeof(userflags)))
-				return -EFAULT;
-			if (cmd == CAPI_SET_FLAGS)
-				cdev->userflags |= userflags;
-			else
-				cdev->userflags &= ~userflags;
-		}
-		return 0;
+	case CAPI_CLR_FLAGS: {
+		unsigned userflags;
+
+		if (copy_from_user(&userflags, argp, sizeof(userflags)))
+			return -EFAULT;
 
+		mutex_lock(&cdev->lock);
+		if (cmd == CAPI_SET_FLAGS)
+			cdev->userflags |= userflags;
+		else
+			cdev->userflags &= ~userflags;
+		mutex_unlock(&cdev->lock);
+		return 0;
+	}
 	case CAPI_GET_FLAGS:
 		if (copy_to_user(argp, &cdev->userflags,
 				 sizeof(cdev->userflags)))
 			return -EFAULT;
 		return 0;
 
-	case CAPI_NCCI_OPENCOUNT:
-		{
-			struct capincci *nccip;
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-			struct capiminor *mp;
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
-			unsigned ncci;
-			int count = 0;
-			if (copy_from_user(&ncci, argp, sizeof(ncci)))
-				return -EFAULT;
+	case CAPI_NCCI_OPENCOUNT: {
+		struct capincci *nccip;
+		unsigned ncci;
+		int count = 0;
 
-			mutex_lock(&cdev->ncci_list_mtx);
-			if ((nccip = capincci_find(cdev, (u32) ncci)) == NULL) {
-				mutex_unlock(&cdev->ncci_list_mtx);
-				return 0;
-			}
-#ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-			if ((mp = nccip->minorp) != NULL) {
-				count += atomic_read(&mp->ttyopencount);
-			}
-#endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
-			mutex_unlock(&cdev->ncci_list_mtx);
-			return count;
-		}
-		return 0;
+		if (copy_from_user(&ncci, argp, sizeof(ncci)))
+			return -EFAULT;
+
+		mutex_lock(&cdev->lock);
+		nccip = capincci_find(cdev, (u32)ncci);
+		if (nccip)
+			count = capincci_minor_opencount(nccip);
+		mutex_unlock(&cdev->lock);
+		return count;
+	}
 
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
-	case CAPI_NCCI_GETUNIT:
-		{
-			struct capincci *nccip;
-			struct capiminor *mp;
-			unsigned ncci;
-			int unit = 0;
-			if (copy_from_user(&ncci, argp,
-					   sizeof(ncci)))
-				return -EFAULT;
-			mutex_lock(&cdev->ncci_list_mtx);
-			nccip = capincci_find(cdev, (u32) ncci);
-			if (!nccip || (mp = nccip->minorp) == NULL) {
-				mutex_unlock(&cdev->ncci_list_mtx);
-				return -ESRCH;
-			}
-			unit = mp->minor;
-			mutex_unlock(&cdev->ncci_list_mtx);
-			return unit;
+	case CAPI_NCCI_GETUNIT: {
+		struct capincci *nccip;
+		struct capiminor *mp;
+		unsigned ncci;
+		int unit = -ESRCH;
+
+		if (copy_from_user(&ncci, argp, sizeof(ncci)))
+			return -EFAULT;
+
+		mutex_lock(&cdev->lock);
+		nccip = capincci_find(cdev, (u32)ncci);
+		if (nccip) {
+			mp = nccip->minorp;
+			if (mp)
+				unit = mp->minor;
 		}
-		return 0;
+		mutex_unlock(&cdev->lock);
+		return unit;
+	}
 #endif /* CONFIG_ISDN_CAPI_MIDDLEWARE */
+
+	default:
+		return -EINVAL;
 	}
-	return -EINVAL;
 }
 
-static int
-capi_open(struct inode *inode, struct file *file)
+static int capi_open(struct inode *inode, struct file *file)
 {
-	int ret;
-	
-	lock_kernel();
-	if (file->private_data)
-		ret = -EEXIST;
-	else if ((file->private_data = capidev_alloc()) == NULL)
-		ret = -ENOMEM;
-	else
-		ret = nonseekable_open(inode, file);
-	unlock_kernel();
-	return ret;
+	struct capidev *cdev;
+
+	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
+	if (!cdev)
+		return -ENOMEM;
+
+	mutex_init(&cdev->lock);
+	skb_queue_head_init(&cdev->recvqueue);
+	init_waitqueue_head(&cdev->recvwait);
+	INIT_LIST_HEAD(&cdev->nccis);
+	file->private_data = cdev;
+
+	mutex_lock(&capidev_list_lock);
+	list_add_tail(&cdev->list, &capidev_list);
+	mutex_unlock(&capidev_list_lock);
+
+	return nonseekable_open(inode, file);
 }
 
-static int
-capi_release(struct inode *inode, struct file *file)
+static int capi_release(struct inode *inode, struct file *file)
 {
-	struct capidev *cdev = (struct capidev *)file->private_data;
+	struct capidev *cdev = file->private_data;
 
-	capidev_free(cdev);
-	file->private_data = NULL;
-	
+	mutex_lock(&capidev_list_lock);
+	list_del(&cdev->list);
+	mutex_unlock(&capidev_list_lock);
+
+	if (cdev->ap.applid)
+		capi20_release(&cdev->ap);
+	skb_queue_purge(&cdev->recvqueue);
+	capincci_free(cdev, 0xffffffff);
+
+	kfree(cdev);
 	return 0;
 }
 
@@ -1023,182 +1034,159 @@ static const struct file_operations capi_fops =
 #ifdef CONFIG_ISDN_CAPI_MIDDLEWARE
 /* -------- tty_operations for capincci ----------------------------- */
 
-static int capin