[SCTP]: sctp doesn't show all associations/endpoints in /proc

When creating a very large number of associations (and endpoints),
/proc/assocs and /proc/eps will not show all of them.  As a result
netstat will not show all of the either.  This is particularly evident
when creating 1000+ associations (or endpoints).  As an example with
1500 tcp style associations over loopback, netstat showed 1420 on my
system instead of 3000.

The reason for this is that the seq_operations start method is invoked
multiple times bacause of the amount of data that is provided.  The
start method always increments the position parameter and since we use
the position as the hash bucket id, we end up skipping hash buckets.

This patch corrects this situation and get's rid of the silly hash-1
decrement.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>

1 files changed, 10 insertions, 18 deletions

diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index 6e4dc28874d7..1b5e5b119f79 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -176,7 +176,7 @@ static void sctp_seq_dump_remote_addrs(struct seq_file *seq, struct sctp_associa
 
 static void * sctp_eps_seq_start(struct seq_file *seq, loff_t *pos)
 {
-        if (*pos > sctp_ep_hashsize)
+        if (*pos >= sctp_ep_hashsize)
                 return NULL;
 
         if (*pos < 0)
@@ -185,8 +185,6 @@ static void * sctp_eps_seq_start(struct seq_file *seq, loff_t *pos)
         if (*pos == 0)
                 seq_printf(seq, " ENDPT     SOCK   STY SST HBKT LPORT   UID INODE LADDRS\n");
 
-        ++*pos;
-
         return (void *)pos;
 }
 
@@ -198,11 +196,9 @@ static void sctp_eps_seq_stop(struct seq_file *seq, void *v)
 
 static void * sctp_eps_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-        if (*pos > sctp_ep_hashsize)
+        if (++*pos >= sctp_ep_hashsize)
                 return NULL;
 
-        ++*pos;
-
         return pos;
 }
 
@@ -216,17 +212,17 @@ static int sctp_eps_seq_show(struct seq_file *seq, void *v)
         struct sock *sk;
         int    hash = *(int *)v;
 
-        if (hash > sctp_ep_hashsize)
+        if (hash >= sctp_ep_hashsize)
                 return -ENOMEM;
 
-        head = &sctp_ep_hashtable[hash-1];
+        head = &sctp_ep_hashtable[hash];
         sctp_local_bh_disable();
         read_lock(&head->lock);
         for (epb = head->chain; epb; epb = epb->next) {
                 ep = sctp_ep(epb);
                 sk = epb->sk;
                 seq_printf(seq, "%8p %8p %-3d %-3d %-4d %-5d %5d %5lu ", ep, sk,
-                           sctp_sk(sk)->type, sk->sk_state, hash-1,
+                           sctp_sk(sk)->type, sk->sk_state, hash,
                            epb->bind_addr.port,
                            sock_i_uid(sk), sock_i_ino(sk));
 
@@ -283,7 +279,7 @@ void sctp_eps_proc_exit(void)
 
 static void * sctp_assocs_seq_start(struct seq_file *seq, loff_t *pos)
 {
-        if (*pos > sctp_assoc_hashsize)
+        if (*pos >= sctp_assoc_hashsize)
                 return NULL;
 
         if (*pos < 0)
@@ -293,8 +289,6 @@ static void * sctp_assocs_seq_start(struct seq_file *seq, loff_t *pos)
                 seq_printf(seq, " ASSOC     SOCK   STY SST ST HBKT ASSOC-ID TX_QUEUE RX_QUEUE UID INODE LPORT "
                                 "RPORT LADDRS <-> RADDRS\n");
 
-        ++*pos;
-
         return (void *)pos;
 }
 
@@ -306,11 +300,9 @@ static void sctp_assocs_seq_stop(struct seq_file *seq, void *v)
 
 static void * sctp_assocs_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-        if (*pos > sctp_assoc_hashsize)
+        if (++*pos >= sctp_assoc_hashsize)
                 return NULL;
 
-        ++*pos;
-
         return pos;
 }
 
@@ -323,10 +315,10 @@ static int sctp_assocs_seq_show(struct seq_file *seq, void *v)
         struct sock *sk;
         int    hash = *(int *)v;
 
-        if (hash > sctp_assoc_hashsize)
+        if (hash >= sctp_assoc_hashsize)
                 return -ENOMEM;
 
-        head = &sctp_assoc_hashtable[hash-1];
+        head = &sctp_assoc_hashtable[hash];
         sctp_local_bh_disable();
         read_lock(&head->lock);
         for (epb = head->chain; epb; epb = epb->next) {
@@ -335,7 +327,7 @@ static int sctp_assocs_seq_show(struct seq_file *seq, void *v)
                 seq_printf(seq,
                            "%8p %8p %-3d %-3d %-2d %-4d %4d %8d %8d %7d %5lu %-5d %5d ",
                            assoc, sk, sctp_sk(sk)->type, sk->sk_state,
-                           assoc->state, hash-1, assoc->assoc_id,
+                           assoc->state, hash, assoc->assoc_id,
                            (sk->sk_rcvbuf - assoc->rwnd),
                            assoc->sndbuf_used,
                            sock_i_uid(sk), sock_i_ino(sk),