Commit 85a64889 authored by Jonathan Lallinger's avatar Jonathan Lallinger Committed by David S. Miller
Browse files

RDSRDMA: Fix cleanup of rds_iw_mr_pool 



In the rds_iw_mr_pool struct the free_pinned field keeps track of
memory pinned by free MRs. While this field is incremented properly
upon allocation, it is never decremented upon unmapping. This would
cause the rds_rdma module to crash the kernel upon unloading, by
triggering the BUG_ON in the rds_iw_destroy_mr_pool function.

This change keeps track of the MRs that become unpinned, so that
free_pinned can be decremented appropriately.

Signed-off-by: default avatarJonathan Lallinger <jonathan@ogc.us>
Signed-off-by: default avatarSteve Wise <swise@ogc.us>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 605b91c8

net/rds/iw_rdma.c

+9 −4
Original line number Diff line number Diff line
@@ -84,7 +84,8 @@ static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool, 
static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);

static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,

			struct list_head *unmap_list,

			struct list_head *kill_list);

			struct list_head *kill_list,

			int *unpinned);

static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr);



static int rds_iw_get_device(struct rds_sock *rs, struct rds_iw_device **rds_iwdev, struct rdma_cm_id **cm_id)
@@ -499,7 +500,7 @@ static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all) 
	LIST_HEAD(unmap_list);

	LIST_HEAD(kill_list);

	unsigned long flags;

	unsigned int nfreed = 0, ncleaned = 0, free_goal;

	unsigned int nfreed = 0, ncleaned = 0, unpinned = 0, free_goal;

	int ret = 0;



	rds_iw_stats_inc(s_iw_rdma_mr_pool_flush);
@@ -524,7 +525,8 @@ static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all) 
	 * will be destroyed by the unmap function.

	 */

	if (!list_empty(&unmap_list)) {

		ncleaned = rds_iw_unmap_fastreg_list(pool, &unmap_list, &kill_list);

		ncleaned = rds_iw_unmap_fastreg_list(pool, &unmap_list,

						     &kill_list, &unpinned);

		/* If we've been asked to destroy all MRs, move those

		 * that were simply cleaned to the kill list */

		if (free_all)
@@ -548,6 +550,7 @@ static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all) 
		spin_unlock_irqrestore(&pool->list_lock, flags);

	}



	atomic_sub(unpinned, &pool->free_pinned);

	atomic_sub(ncleaned, &pool->dirty_count);

	atomic_sub(nfreed, &pool->item_count);
@@ -828,7 +831,8 @@ static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool, 


static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool,

				struct list_head *unmap_list,

				struct list_head *kill_list)

				struct list_head *kill_list,

				int *unpinned)

{

	struct rds_iw_mapping *mapping, *next;

	unsigned int ncleaned = 0;
@@ -855,6 +859,7 @@ static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool, 


		spin_lock_irqsave(&pool->list_lock, flags);

		list_for_each_entry_safe(mapping, next, unmap_list, m_list) {

			*unpinned += mapping->m_sg.len;

			list_move(&mapping->m_list, &laundered);

			ncleaned++;

		}

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