[PATCH 4.4 44/78] RDMA/iser: Fix possible mr leak on device removal event

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sagi Grimberg <s...@grimberg.me>


[ Upstream commit ea174c9573b0e0c8bc1a7a90fe9360ccb7aa9cbb ]

When the rdma device is removed, we must cleanup all
the rdma resources within the DEVICE_REMOVAL event
handler to let the device teardown gracefully. When
this happens with live I/O, some memory regions are
occupied. Thus, track them too and dereg all the mr's.

We are safe with mr access by iscsi_iser_cleanup_task.

Reported-by: Raju Rangoju <ra...@chelsio.com>
Signed-off-by: Sagi Grimberg <s...@grimberg.me>
Reviewed-by: Max Gurtovoy <m...@mellanox.com>
Reviewed-by: Max Gurtovoy <m...@mellanox.com>
Signed-off-by: Doug Ledford <dledf...@redhat.com>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/infiniband/ulp/iser/iscsi_iser.h |    2 ++
 drivers/infiniband/ulp/iser/iser_verbs.c |    8 +++++---
 2 files changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/infiniband/ulp/iser/iscsi_iser.h
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
@@ -450,6 +450,7 @@ struct iser_fr_desc {
        struct list_head                  list;
        struct iser_reg_resources         rsc;
        struct iser_pi_context           *pi_ctx;
+       struct list_head                  all_list;
 };
 
 /**
@@ -463,6 +464,7 @@ struct iser_fr_pool {
        struct list_head        list;
        spinlock_t              lock;
        int                     size;
+       struct list_head        all_list;
 };
 
 /**
--- a/drivers/infiniband/ulp/iser/iser_verbs.c
+++ b/drivers/infiniband/ulp/iser/iser_verbs.c
@@ -405,6 +405,7 @@ int iser_alloc_fastreg_pool(struct ib_co
        int i, ret;
 
        INIT_LIST_HEAD(&fr_pool->list);
+       INIT_LIST_HEAD(&fr_pool->all_list);
        spin_lock_init(&fr_pool->lock);
        fr_pool->size = 0;
        for (i = 0; i < cmds_max; i++) {
@@ -416,6 +417,7 @@ int iser_alloc_fastreg_pool(struct ib_co
                }
 
                list_add_tail(&desc->list, &fr_pool->list);
+               list_add_tail(&desc->all_list, &fr_pool->all_list);
                fr_pool->size++;
        }
 
@@ -435,13 +437,13 @@ void iser_free_fastreg_pool(struct ib_co
        struct iser_fr_desc *desc, *tmp;
        int i = 0;
 
-       if (list_empty(&fr_pool->list))
+       if (list_empty(&fr_pool->all_list))
                return;
 
        iser_info("freeing conn %p fr pool\n", ib_conn);
 
-       list_for_each_entry_safe(desc, tmp, &fr_pool->list, list) {
-               list_del(&desc->list);
+       list_for_each_entry_safe(desc, tmp, &fr_pool->all_list, all_list) {
+               list_del(&desc->all_list);
                iser_free_reg_res(&desc->rsc);
                if (desc->pi_ctx)
                        iser_free_pi_ctx(desc->pi_ctx);