rds: set fmr pool dirty_count correctly

In rds_ib_flush_mr_pool() the setting of dirty_count is wrong in case
"free_all" is true -- "clean" ones also counted as dirty. dirty_count
being negative is seen in vmcore.

Orabug: 21551548

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Chien-Hua Yen <chien.yen@oracle.com>

diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index e8d6e48d2e76a5569bbaa38891fdc8de91229ae9..7083165202cc5dbda51ef86bf7957ac2896775fa 100644 (file)
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -599,12 +599,14 @@ static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int fr
 /*
  * given an xlist of mrs, put them all into the list_head for more processing
  */
-static void xlist_append_to_list(struct xlist_head *xlist, struct list_head *list)
+static int xlist_append_to_list(struct xlist_head *xlist,
+                               struct list_head *list)
 {
        struct rds_ib_mr *ibmr;
        struct xlist_head splice;
        struct xlist_head *cur;
        struct xlist_head *next;
+       int count = 0;
 
        splice.next = NULL;
        xlist_splice(xlist, &splice);
@@ -614,7 +616,9 @@ static void xlist_append_to_list(struct xlist_head *xlist, struct list_head *lis
                ibmr = list_entry(cur, struct rds_ib_mr, xlist);
                list_add_tail(&ibmr->unmap_list, list);
                cur = next;
+               count++;
        }
+       return count;
 }
 
 /*
@@ -654,7 +658,7 @@ static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
        LIST_HEAD(unmap_list);
        LIST_HEAD(fmr_list);
        unsigned long unpinned = 0;
-       unsigned int nfreed = 0, ncleaned = 0, free_goal;
+       unsigned int nfreed = 0, dirty_to_clean = 0, free_goal;
        int ret = 0;
 
        if (pool->pool_type == RDS_IB_MR_8K_POOL)
@@ -699,8 +703,8 @@ static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
        /* Get the list of all MRs to be dropped. Ordering matters -
         * we want to put drop_list ahead of free_list.
         */
-       xlist_append_to_list(&pool->drop_list, &unmap_list);
-       xlist_append_to_list(&pool->free_list, &unmap_list);
+       dirty_to_clean = xlist_append_to_list(&pool->drop_list, &unmap_list);
+       dirty_to_clean += xlist_append_to_list(&pool->free_list, &unmap_list);
        if (free_all)
                xlist_append_to_list(&pool->clean_list, &unmap_list);
 
@@ -731,7 +735,6 @@ static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
                        kfree(ibmr);
                        nfreed++;
                }
-               ncleaned++;
        }
 
        if (!list_empty(&unmap_list)) {
@@ -757,7 +760,7 @@ static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
        }
 
        atomic_sub(unpinned, &pool->free_pinned);
-       atomic_sub(ncleaned, &pool->dirty_count);
+       atomic_sub(dirty_to_clean, &pool->dirty_count);
        atomic_sub(nfreed, &pool->item_count);
 
 out: