LU-1589 lnet: read peers of /proc could be endless

There is a chance that reading /proc/sys/lnet/peers could be endless
because we didn't set correct condition for ending. This bug is
introduced by commit a07e9d350b3e500c7be877f6dcf54380b86a9cbe of LU-56

Signed-off-by: Liang Zhen <liang@whamcloud.com>
Change-Id: I25f6dad4a926bb7c62a4b1b1d4c3a86c783e3f7a
Reviewed-on: http://review.whamcloud.com/3251
Tested-by: Hudson
Reviewed-by: Doug Oucharek <doug@whamcloud.com>
Reviewed-by: Bobi Jam <bobijam@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lnet/lnet/router_proc.c b/lnet/lnet/router_proc.c
index f64bea2..6bf4773 100644 (file)
--- a/lnet/lnet/router_proc.c
+++ b/lnet/lnet/router_proc.c
@@ -58,7 +58,7 @@ enum {
 /*
  * NB: max allowed LNET_CPT_BITS is 8 on 64-bit system and 2 on 32-bit system
  */
-#define LNET_PROC_CPT_BITS     LNET_CPT_BITS
+#define LNET_PROC_CPT_BITS     (LNET_CPT_BITS + 1)
 /* change version, 16 bits or 8 bits */
 #define LNET_PROC_VER_BITS     MAX(((MIN(LNET_LOFFT_BITS, 64)) / 4), 8)
 
@@ -413,8 +413,8 @@ int LL_PROC_PROTO(proc_lnet_peers)
        char                    *s;
        int                     cpt  = LNET_PROC_CPT_GET(*ppos);
        int                     ver  = LNET_PROC_VER_GET(*ppos);
-       int                     hoff = LNET_PROC_HOFF_GET(*ppos);
        int                     hash = LNET_PROC_HASH_GET(*ppos);
+       int                     hoff = LNET_PROC_HOFF_GET(*ppos);
        int                     rc = 0;
        int                     len;
 
@@ -424,8 +424,10 @@ int LL_PROC_PROTO(proc_lnet_peers)
        if (*lenp == 0)
                return 0;
 
-       if (cpt >= LNET_CPT_NUMBER)
+       if (cpt >= LNET_CPT_NUMBER) {
+               *lenp = 0;
                return 0;
+       }
 
         LIBCFS_ALLOC(tmpstr, tmpsiz);
         if (tmpstr == NULL)
@@ -442,11 +444,14 @@ int LL_PROC_PROTO(proc_lnet_peers)
 
                hoff++;
        } else {
-               struct lnet_peer        *peer   = NULL;
-               cfs_list_t              *p      = NULL;
-               int                     skip    = hoff - 1;
-
+               struct lnet_peer        *peer;
+               cfs_list_t              *p;
+               int                     skip;
  again:
+               p = NULL;
+               peer = NULL;
+               skip = hoff - 1;
+
                lnet_net_lock(cpt);
                ptable = the_lnet.ln_peer_tables[cpt];
                if (hoff == 1)
@@ -536,14 +541,14 @@ int LL_PROC_PROTO(proc_lnet_peers)
 
                } else { /* peer is NULL */
                        lnet_net_unlock(cpt);
+               }
 
-                       if (hash == LNET_PEER_HASH_SIZE &&
-                           cpt < LNET_CPT_NUMBER - 1) {
-                               cpt++;
-                               hash = 0;
-                               hoff = 1;
+               if (hash == LNET_PEER_HASH_SIZE) {
+                       cpt++;
+                       hash = 0;
+                       hoff = 1;
+                       if (peer == NULL && cpt < LNET_CPT_NUMBER)
                                goto again;
-                       }
                }
         }