RDS: fix fmr pool dirty_count

In rds_ib_flush_mr_pool(), dirty_count accounts the clean ones
which is wrong. This can lead to a negative dirty count value.

Lets fix it.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 6 deletions

diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index 7b7aac8cdb56..a275b7d205ef 100644
--- a/net/rds/ib_rdma.c
+++ b/net/rds/ib_rdma.c
@@ -528,11 +528,13 @@ static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int fr
 /*
  * given an llist of mrs, put them all into the list_head for more processing
  */
-static void llist_append_to_list(struct llist_head *llist, struct list_head *list)
+static unsigned int llist_append_to_list(struct llist_head *llist,
+                                         struct list_head *list)
 {
         struct rds_ib_mr *ibmr;
         struct llist_node *node;
         struct llist_node *next;
+        unsigned int count = 0;
 
         node = llist_del_all(llist);
         while (node) {
@@ -540,7 +542,9 @@ static void llist_append_to_list(struct llist_head *llist, struct list_head *lis
                 ibmr = llist_entry(node, struct rds_ib_mr, llnode);
                 list_add_tail(&ibmr->unmap_list, list);
                 node = next;
+                count++;
         }
+        return count;
 }
 
 /*
@@ -581,7 +585,7 @@ 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;
 
         rds_ib_stats_inc(s_ib_rdma_mr_pool_flush);
@@ -623,8 +627,8 @@ 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.
          */
-        llist_append_to_list(&pool->drop_list, &unmap_list);
-        llist_append_to_list(&pool->free_list, &unmap_list);
+        dirty_to_clean = llist_append_to_list(&pool->drop_list, &unmap_list);
+        dirty_to_clean += llist_append_to_list(&pool->free_list, &unmap_list);
         if (free_all)
                 llist_append_to_list(&pool->clean_list, &unmap_list);
 
@@ -652,7 +656,6 @@ static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
                         kfree(ibmr);
                         nfreed++;
                 }
-                ncleaned++;
         }
 
         if (!list_empty(&unmap_list)) {
@@ -678,7 +681,7 @@ 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: