net: convert /proc/net/rt_acct to seq_file

Rewrite statistics accumulation to be in terms of structure fields,
not raw u32 additions. Keep them in same order, though.

This is the last user of create_proc_read_entry() in net/,
please NAK all new ones as well as all new ->write_proc, ->read_proc and
create_proc_entry() users. Cc me if there are problems. :-)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 35 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index aea7bb369cfa..9889fbd96487 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -513,43 +513,42 @@ static const struct file_operations rt_cpu_seq_fops = {
 };
 
 #ifdef CONFIG_NET_CLS_ROUTE
-static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
-                           int length, int *eof, void *data)
-{
-        unsigned int i;
-
-        if ((offset & 3) || (length & 3))
-                return -EIO;
-
-        if (offset >= sizeof(struct ip_rt_acct) * 256) {
-                *eof = 1;
-                return 0;
-        }
-
-        if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
-                length = sizeof(struct ip_rt_acct) * 256 - offset;
-                *eof = 1;
+static int rt_acct_proc_show(struct seq_file *m, void *v)
+{
+        struct ip_rt_acct *dst, *src;
+        unsigned int i, j;
+
+        dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
+        if (!dst)
+                return -ENOMEM;
+
+        for_each_possible_cpu(i) {
+                src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
+                for (j = 0; j < 256; j++) {
+                        dst[j].o_bytes   += src[j].o_bytes;
+                        dst[j].o_packets += src[j].o_packets;
+                        dst[j].i_bytes   += src[j].i_bytes;
+                        dst[j].i_packets += src[j].i_packets;
+                }
         }
 
-        offset /= sizeof(u32);
-
-        if (length > 0) {
-                u32 *dst = (u32 *) buffer;
-
-                *start = buffer;
-                memset(dst, 0, length);
-
-                for_each_possible_cpu(i) {
-                        unsigned int j;
-                        u32 *src;
+        seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
+        kfree(dst);
+        return 0;
+}
 
-                        src = ((u32 *) per_cpu_ptr(ip_rt_acct, i)) + offset;
-                        for (j = 0; j < length/4; j++)
-                                dst[j] += src[j];
-                }
-        }
-        return length;
+static int rt_acct_proc_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, rt_acct_proc_show, NULL);
 }
+
+static const struct file_operations rt_acct_proc_fops = {
+        .owner          = THIS_MODULE,
+        .open           = rt_acct_proc_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
 #endif
 
 static int __net_init ip_rt_do_proc_init(struct net *net)
@@ -567,8 +566,7 @@ static int __net_init ip_rt_do_proc_init(struct net *net)
                 goto err2;
 
 #ifdef CONFIG_NET_CLS_ROUTE
-        pde = create_proc_read_entry("rt_acct", 0, net->proc_net,
-                        ip_rt_acct_read, NULL);
+        pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
         if (!pde)
                 goto err3;
 #endif