Revert "NET: Fix locking issues in PPP, 6pack, mkiss and strip line disciplines."
David S. Miller [Tue, 14 Jul 2009 20:13:41 +0000 (13:13 -0700)]
This reverts commit adeab1afb7de89555c69aab5ca21300c14af6369.

As Alan Cox explained, the TTY layer changes that went recently
to get rid of the tty->low_latency stuff fixes this already,
and even for -stable it's the ->low_latency changes that should
go in to fix this, rather than this patch.

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hamradio/6pack.c
drivers/net/hamradio/mkiss.c
drivers/net/ppp_async.c
drivers/net/ppp_synctty.c
drivers/net/wireless/strip.c

index 913a564..1551600 100644 (file)
@@ -398,14 +398,13 @@ static DEFINE_RWLOCK(disc_data_lock);
                                                                                 
 static struct sixpack *sp_get(struct tty_struct *tty)
 {
-       unsigned long flags;
        struct sixpack *sp;
 
-       read_lock_irqsave(&disc_data_lock, flags);
+       read_lock(&disc_data_lock);
        sp = tty->disc_data;
        if (sp)
                atomic_inc(&sp->refcnt);
-       read_unlock_irqrestore(&disc_data_lock, flags);
+       read_unlock(&disc_data_lock);
 
        return sp;
 }
@@ -689,13 +688,12 @@ out:
  */
 static void sixpack_close(struct tty_struct *tty)
 {
-       unsigned long flags;
        struct sixpack *sp;
 
-       write_lock_irqsave(&disc_data_lock, flags);
+       write_lock(&disc_data_lock);
        sp = tty->disc_data;
        tty->disc_data = NULL;
-       write_unlock_irqrestore(&disc_data_lock, flags);
+       write_unlock(&disc_data_lock);
        if (!sp)
                return;
 
index a728650..fda2fc8 100644 (file)
@@ -244,16 +244,15 @@ static int kiss_esc_crc(unsigned char *s, unsigned char *d, unsigned short crc,
 /* Send one completely decapsulated AX.25 packet to the AX.25 layer. */
 static void ax_bump(struct mkiss *ax)
 {
-       unsigned long flags;
        struct sk_buff *skb;
        int count;
 
-       spin_lock_irqsave(&ax->buflock, flags);
+       spin_lock_bh(&ax->buflock);
        if (ax->rbuff[0] > 0x0f) {
                if (ax->rbuff[0] & 0x80) {
                        if (check_crc_16(ax->rbuff, ax->rcount) < 0) {
                                ax->dev->stats.rx_errors++;
-                               spin_unlock_irqrestore(&ax->buflock, flags);
+                               spin_unlock_bh(&ax->buflock);
 
                                return;
                        }
@@ -268,7 +267,7 @@ static void ax_bump(struct mkiss *ax)
                } else if (ax->rbuff[0] & 0x20)  {
                        if (check_crc_flex(ax->rbuff, ax->rcount) < 0) {
                                ax->dev->stats.rx_errors++;
-                               spin_unlock_irqrestore(&ax->buflock, flags);
+                               spin_unlock_bh(&ax->buflock);
                                return;
                        }
                        if (ax->crcmode != CRC_MODE_FLEX && ax->crcauto) {
@@ -295,7 +294,7 @@ static void ax_bump(struct mkiss *ax)
                printk(KERN_ERR "mkiss: %s: memory squeeze, dropping packet.\n",
                       ax->dev->name);
                ax->dev->stats.rx_dropped++;
-               spin_unlock_irqrestore(&ax->buflock, flags);
+               spin_unlock_bh(&ax->buflock);
                return;
        }
 
@@ -304,13 +303,11 @@ static void ax_bump(struct mkiss *ax)
        netif_rx(skb);
        ax->dev->stats.rx_packets++;
        ax->dev->stats.rx_bytes += count;
-       spin_unlock_irqrestore(&ax->buflock, flags);
+       spin_unlock_bh(&ax->buflock);
 }
 
 static void kiss_unesc(struct mkiss *ax, unsigned char s)
 {
-       unsigned long flags;
-
        switch (s) {
        case END:
                /* drop keeptest bit = VSV */
@@ -337,18 +334,18 @@ static void kiss_unesc(struct mkiss *ax, unsigned char s)
                break;
        }
 
-       spin_lock_irqsave(&ax->buflock, flags);
+       spin_lock_bh(&ax->buflock);
        if (!test_bit(AXF_ERROR, &ax->flags)) {
                if (ax->rcount < ax->buffsize) {
                        ax->rbuff[ax->rcount++] = s;
-                       spin_unlock_irqrestore(&ax->buflock, flags);
+                       spin_unlock_bh(&ax->buflock);
                        return;
                }
 
                ax->dev->stats.rx_over_errors++;
                set_bit(AXF_ERROR, &ax->flags);
        }
-       spin_unlock_irqrestore(&ax->buflock, flags);
+       spin_unlock_bh(&ax->buflock);
 }
 
 static int ax_set_mac_address(struct net_device *dev, void *addr)
@@ -370,7 +367,6 @@ static void ax_changedmtu(struct mkiss *ax)
 {
        struct net_device *dev = ax->dev;
        unsigned char *xbuff, *rbuff, *oxbuff, *orbuff;
-       unsigned long flags;
        int len;
 
        len = dev->mtu * 2;
@@ -396,7 +392,7 @@ static void ax_changedmtu(struct mkiss *ax)
                return;
        }
 
-       spin_lock_irqsave(&ax->buflock, flags);
+       spin_lock_bh(&ax->buflock);
 
        oxbuff    = ax->xbuff;
        ax->xbuff = xbuff;
@@ -427,7 +423,7 @@ static void ax_changedmtu(struct mkiss *ax)
        ax->mtu      = dev->mtu + 73;
        ax->buffsize = len;
 
-       spin_unlock_irqrestore(&ax->buflock, flags);
+       spin_unlock_bh(&ax->buflock);
 
        kfree(oxbuff);
        kfree(orbuff);
@@ -437,7 +433,6 @@ static void ax_changedmtu(struct mkiss *ax)
 static void ax_encaps(struct net_device *dev, unsigned char *icp, int len)
 {
        struct mkiss *ax = netdev_priv(dev);
-       unsigned long flags;
        unsigned char *p;
        int actual, count;
 
@@ -454,7 +449,7 @@ static void ax_encaps(struct net_device *dev, unsigned char *icp, int len)
 
        p = icp;
 
-       spin_lock_irqsave(&ax->buflock, flags);
+       spin_lock_bh(&ax->buflock);
        if ((*p & 0x0f) != 0) {
                /* Configuration Command (kissparms(1).
                 * Protocol spec says: never append CRC.
@@ -484,7 +479,7 @@ static void ax_encaps(struct net_device *dev, unsigned char *icp, int len)
                                ax->crcauto = (cmd ? 0 : 1);
                                printk(KERN_INFO "mkiss: %s: crc mode %s %d\n", ax->dev->name, (len) ? "set to" : "is", cmd);
                        }
-                       spin_unlock_irqrestore(&ax->buflock, flags);
+                       spin_unlock_bh(&ax->buflock);
                        netif_start_queue(dev);
 
                        return;
@@ -517,7 +512,7 @@ static void ax_encaps(struct net_device *dev, unsigned char *icp, int len)
                        count = kiss_esc(p, (unsigned char *)ax->xbuff, len);
                }
        }
-       spin_unlock_irqrestore(&ax->buflock, flags);
+       spin_unlock_bh(&ax->buflock);
 
        set_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags);
        actual = ax->tty->ops->write(ax->tty, ax->xbuff, count);
@@ -709,14 +704,13 @@ static DEFINE_RWLOCK(disc_data_lock);
 
 static struct mkiss *mkiss_get(struct tty_struct *tty)
 {
-       unsigned long flags;
        struct mkiss *ax;
 
-       read_lock_irqsave(&disc_data_lock, flags);
+       read_lock(&disc_data_lock);
        ax = tty->disc_data;
        if (ax)
                atomic_inc(&ax->refcnt);
-       read_unlock_irqrestore(&disc_data_lock, flags);
+       read_unlock(&disc_data_lock);
 
        return ax;
 }
@@ -815,13 +809,12 @@ out:
 
 static void mkiss_close(struct tty_struct *tty)
 {
-       unsigned long flags;
        struct mkiss *ax;
 
-       write_lock_irqsave(&disc_data_lock, flags);
+       write_lock(&disc_data_lock);
        ax = tty->disc_data;
        tty->disc_data = NULL;
-       write_unlock_irqrestore(&disc_data_lock, flags);
+       write_unlock(&disc_data_lock);
 
        if (!ax)
                return;
index 1fd319b..17c116b 100644 (file)
@@ -132,15 +132,13 @@ static DEFINE_RWLOCK(disc_data_lock);
 
 static struct asyncppp *ap_get(struct tty_struct *tty)
 {
-       unsigned long flags;
        struct asyncppp *ap;
 
-       read_lock_irqsave(&disc_data_lock, flags);
+       read_lock(&disc_data_lock);
        ap = tty->disc_data;
        if (ap != NULL)
                atomic_inc(&ap->refcnt);
-       read_unlock_irqrestore(&disc_data_lock, flags);
-
+       read_unlock(&disc_data_lock);
        return ap;
 }
 
@@ -217,13 +215,12 @@ ppp_asynctty_open(struct tty_struct *tty)
 static void
 ppp_asynctty_close(struct tty_struct *tty)
 {
-       unsigned long flags;
        struct asyncppp *ap;
 
-       write_lock_irqsave(&disc_data_lock, flags);
+       write_lock_irq(&disc_data_lock);
        ap = tty->disc_data;
        tty->disc_data = NULL;
-       write_unlock_irqrestore(&disc_data_lock, flags);
+       write_unlock_irq(&disc_data_lock);
        if (!ap)
                return;
 
index 1b3f75f..aa3d39f 100644 (file)
@@ -182,15 +182,13 @@ static DEFINE_RWLOCK(disc_data_lock);
 
 static struct syncppp *sp_get(struct tty_struct *tty)
 {
-       unsigned long flags;
        struct syncppp *ap;
 
-       read_lock_irqsave(&disc_data_lock, flags);
+       read_lock(&disc_data_lock);
        ap = tty->disc_data;
        if (ap != NULL)
                atomic_inc(&ap->refcnt);
-       read_unlock_irqrestore(&disc_data_lock, flags);
-
+       read_unlock(&disc_data_lock);
        return ap;
 }
 
@@ -264,13 +262,12 @@ ppp_sync_open(struct tty_struct *tty)
 static void
 ppp_sync_close(struct tty_struct *tty)
 {
-       unsigned long flags;
        struct syncppp *ap;
 
-       write_lock_irqsave(&disc_data_lock, flags);
+       write_lock_irq(&disc_data_lock);
        ap = tty->disc_data;
        tty->disc_data = NULL;
-       write_unlock_irqrestore(&disc_data_lock, flags);
+       write_unlock_irq(&disc_data_lock);
        if (!ap)
                return;
 
index 3d39f65..38366a5 100644 (file)
@@ -856,7 +856,6 @@ static int strip_change_mtu(struct net_device *dev, int new_mtu)
        unsigned char *orbuff = strip_info->rx_buff;
        unsigned char *osbuff = strip_info->sx_buff;
        unsigned char *otbuff = strip_info->tx_buff;
-       unsigned long flags;
 
        if (new_mtu > MAX_SEND_MTU) {
                printk(KERN_ERR
@@ -865,11 +864,11 @@ static int strip_change_mtu(struct net_device *dev, int new_mtu)
                return -EINVAL;
        }
 
-       spin_lock_irqsave(&strip_lock, flags);
+       spin_lock_bh(&strip_lock);
        if (!allocate_buffers(strip_info, new_mtu)) {
                printk(KERN_ERR "%s: unable to grow strip buffers, MTU change cancelled.\n",
                       strip_info->dev->name);
-               spin_unlock_irqrestore(&strip_lock, flags);
+               spin_unlock_bh(&strip_lock);
                return -ENOMEM;
        }
 
@@ -893,7 +892,7 @@ static int strip_change_mtu(struct net_device *dev, int new_mtu)
                }
        }
        strip_info->tx_head = strip_info->tx_buff;
-       spin_unlock_irqrestore(&strip_lock, flags);
+       spin_unlock_bh(&strip_lock);
 
        printk(KERN_NOTICE "%s: strip MTU changed fom %d to %d.\n",
               strip_info->dev->name, old_mtu, strip_info->mtu);
@@ -984,13 +983,10 @@ static void strip_seq_neighbours(struct seq_file *seq,
                           const MetricomNodeTable * table,
                           const char *title)
 {
-       unsigned long flags;
+       /* We wrap this in a do/while loop, so if the table changes */
+       /* while we're reading it, we just go around and try again. */
        struct timeval t;
 
-       /*
-        * We wrap this in a do/while loop, so if the table changes
-        * while we're reading it, we just go around and try again.
-        */
        do {
                int i;
                t = table->timestamp;
@@ -999,9 +995,9 @@ static void strip_seq_neighbours(struct seq_file *seq,
                for (i = 0; i < table->num_nodes; i++) {
                        MetricomNode node;
 
-                       spin_lock_irqsave(&strip_lock, flags);
+                       spin_lock_bh(&strip_lock);
                        node = table->node[i];
-                       spin_unlock_irqrestore(&strip_lock, flags);
+                       spin_unlock_bh(&strip_lock);
                        seq_printf(seq, "  %s\n", node.c);
                }
        } while (table->timestamp.tv_sec != t.tv_sec
@@ -1540,7 +1536,6 @@ static void strip_send(struct strip *strip_info, struct sk_buff *skb)
 static int strip_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct strip *strip_info = netdev_priv(dev);
-       unsigned long flags;
 
        if (!netif_running(dev)) {
                printk(KERN_ERR "%s: xmit call when iface is down\n",
@@ -1579,11 +1574,11 @@ static int strip_xmit(struct sk_buff *skb, struct net_device *dev)
                               strip_info->dev->name, sx_pps_count / 8);
        }
 
-       spin_lock_irqsave(&strip_lock, flags);
+       spin_lock_bh(&strip_lock);
 
        strip_send(strip_info, skb);
 
-       spin_unlock_irqrestore(&strip_lock, flags);
+       spin_unlock_bh(&strip_lock);
 
        if (skb)
                dev_kfree_skb(skb);
@@ -2268,13 +2263,12 @@ static void strip_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 {
        struct strip *strip_info = tty->disc_data;
        const unsigned char *end = cp + count;
-       unsigned long flags;
 
        if (!strip_info || strip_info->magic != STRIP_MAGIC
            || !netif_running(strip_info->dev))
                return;
 
-       spin_lock_irqsave(&strip_lock, flags);
+       spin_lock_bh(&strip_lock);
 #if 0
        {
                struct timeval tv;
@@ -2341,7 +2335,7 @@ static void strip_receive_buf(struct tty_struct *tty, const unsigned char *cp,
                }
                cp++;
        }
-       spin_unlock_irqrestore(&strip_lock, flags);
+       spin_unlock_bh(&strip_lock);
 }
 
 
@@ -2529,11 +2523,9 @@ static void strip_dev_setup(struct net_device *dev)
 
 static void strip_free(struct strip *strip_info)
 {
-       unsigned long flags;
-
-       spin_lock_irqsave(&strip_lock, flags);
+       spin_lock_bh(&strip_lock);
        list_del_rcu(&strip_info->list);
-       spin_unlock_irqrestore(&strip_lock, flags);
+       spin_unlock_bh(&strip_lock);
 
        strip_info->magic = 0;
 
@@ -2547,7 +2539,6 @@ static void strip_free(struct strip *strip_info)
 static struct strip *strip_alloc(void)
 {
        struct list_head *n;
-       unsigned long flags;
        struct net_device *dev;
        struct strip *strip_info;
 
@@ -2571,7 +2562,7 @@ static struct strip *strip_alloc(void)
        strip_info->idle_timer.function = strip_IdleTask;
 
 
-       spin_lock_irqsave(&strip_lock, flags);
+       spin_lock_bh(&strip_lock);
  rescan:
        /*
         * Search the list to find where to put our new entry
@@ -2590,7 +2581,7 @@ static struct strip *strip_alloc(void)
        sprintf(dev->name, "st%ld", dev->base_addr);
 
        list_add_tail_rcu(&strip_info->list, &strip_list);
-       spin_unlock_irqrestore(&strip_lock, flags);
+       spin_unlock_bh(&strip_lock);
 
        return strip_info;
 }