xfs: remove nr_to_write writeback windup.

[safe/jmp/linux-2.6] / net / ipv4 / tcp_probe.c

diff --git a/net/ipv4/tcp_probe.c b/net/ipv4/tcp_probe.c
index 25524d4..f8efada 100644 (file)
--- a/net/ipv4/tcp_probe.c
+++ b/net/ipv4/tcp_probe.c
@@ -22,6 +22,7 @@
 #include <linux/kprobes.h>
 #include <linux/socket.h>
 #include <linux/tcp.h>
+#include <linux/slab.h>
 #include <linux/proc_fs.h>
 #include <linux/module.h>
 #include <linux/ktime.h>
@@ -39,9 +40,9 @@ static int port __read_mostly = 0;
 MODULE_PARM_DESC(port, "Port to match (0=all)");
 module_param(port, int, 0);
 
-static int bufsize __read_mostly = 4096;
+static unsigned int bufsize __read_mostly = 4096;
 MODULE_PARM_DESC(bufsize, "Log buffer size in packets (4096)");
-module_param(bufsize, int, 0);
+module_param(bufsize, uint, 0);
 
 static int full __read_mostly;
 MODULE_PARM_DESC(full, "Full log (1=every ack packet received,  0=only cwnd changes)");
@@ -75,12 +76,12 @@ static struct {
 
 static inline int tcp_probe_used(void)
 {
-       return (tcp_probe.head - tcp_probe.tail) % bufsize;
+       return (tcp_probe.head - tcp_probe.tail) & (bufsize - 1);
 }
 
 static inline int tcp_probe_avail(void)
 {
-       return bufsize - tcp_probe_used();
+       return bufsize - tcp_probe_used() - 1;
 }
 
 /*
@@ -94,8 +95,9 @@ static int jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
        const struct inet_sock *inet = inet_sk(sk);
 
        /* Only update if port matches */
-       if ((port == 0 || ntohs(inet->dport) == port || ntohs(inet->sport) == port)
-           && (full || tp->snd_cwnd != tcp_probe.lastcwnd)) {
+       if ((port == 0 || ntohs(inet->inet_dport) == port ||
+            ntohs(inet->inet_sport) == port) &&
+           (full || tp->snd_cwnd != tcp_probe.lastcwnd)) {
 
                spin_lock(&tcp_probe.lock);
                /* If log fills, just silently drop */
@@ -103,10 +105,10 @@ static int jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
                        struct tcp_log *p = tcp_probe.log + tcp_probe.head;
 
                        p->tstamp = ktime_get();
-                       p->saddr = inet->saddr;
-                       p->sport = inet->sport;
-                       p->daddr = inet->daddr;
-                       p->dport = inet->dport;
+                       p->saddr = inet->inet_saddr;
+                       p->sport = inet->inet_sport;
+                       p->daddr = inet->inet_daddr;
+                       p->dport = inet->inet_dport;
                        p->length = skb->len;
                        p->snd_nxt = tp->snd_nxt;
                        p->snd_una = tp->snd_una;
@@ -115,7 +117,7 @@ static int jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
                        p->ssthresh = tcp_current_ssthresh(sk);
                        p->srtt = tp->srtt >> 3;
 
-                       tcp_probe.head = (tcp_probe.head + 1) % bufsize;
+                       tcp_probe.head = (tcp_probe.head + 1) & (bufsize - 1);
                }
                tcp_probe.lastcwnd = tp->snd_cwnd;
                spin_unlock(&tcp_probe.lock);
@@ -148,7 +150,7 @@ static int tcpprobe_open(struct inode * inode, struct file * file)
 static int tcpprobe_sprint(char *tbuf, int n)
 {
        const struct tcp_log *p
-               = tcp_probe.log + tcp_probe.tail % bufsize;
+               = tcp_probe.log + tcp_probe.tail;
        struct timespec tv
                = ktime_to_timespec(ktime_sub(p->tstamp, tcp_probe.start));
 
@@ -165,9 +167,10 @@ static int tcpprobe_sprint(char *tbuf, int n)
 static ssize_t tcpprobe_read(struct file *file, char __user *buf,
                             size_t len, loff_t *ppos)
 {
-       int error = 0, cnt = 0;
+       int error = 0;
+       size_t cnt = 0;
 
-       if (!buf || len < 0)
+       if (!buf)
                return -EINVAL;
 
        while (cnt < len) {
@@ -190,7 +193,7 @@ static ssize_t tcpprobe_read(struct file *file, char __user *buf,
                width = tcpprobe_sprint(tbuf, sizeof(tbuf));
 
                if (cnt + width < len)
-                       tcp_probe.tail = (tcp_probe.tail + 1) % bufsize;
+                       tcp_probe.tail = (tcp_probe.tail + 1) & (bufsize - 1);
 
                spin_unlock_bh(&tcp_probe.lock);
 
@@ -220,9 +223,10 @@ static __init int tcpprobe_init(void)
        init_waitqueue_head(&tcp_probe.wait);
        spin_lock_init(&tcp_probe.lock);
 
-       if (bufsize < 0)
+       if (bufsize == 0)
                return -EINVAL;
 
+       bufsize = roundup_pow_of_two(bufsize);
        tcp_probe.log = kcalloc(bufsize, sizeof(struct tcp_log), GFP_KERNEL);
        if (!tcp_probe.log)
                goto err0;
@@ -234,7 +238,7 @@ static __init int tcpprobe_init(void)
        if (ret)
                goto err1;
 
-       pr_info("TCP probe registered (port=%d)\n", port);
+       pr_info("TCP probe registered (port=%d) bufsize=%u\n", port, bufsize);
        return 0;
  err1:
        proc_net_remove(&init_net, procname);