[PATCH 3/6] RDS: fix fmr pool dirty_count

From: Santosh Shilimkar
Date: Tue Aug 25 2015 - 15:04:14 EST


From: Wengang Wang <wen.gang.wang@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Santosh Shilimkar <ssantosh@xxxxxxxxxx>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
---
net/rds/ib_rdma.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c
index 7b7aac8..a275b7d 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:
--
1.9.1

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