Fixing the possible deadlock in write_gid:
write_gid -> write_lock()
<interrupt>
        find_gid -> read_lock_irqsave()
                    ** DEAD LOCK **LOCK

Fixing it by changing the write_lock to write_lock_irqsave.

Squash-into: 'IB/core: Add RoCE GID table management'
Signed-off-by: Matan Barak <mat...@mellanox.com>
---
 drivers/infiniband/core/cache.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c
index 58a44bd..d7fdcb7 100644
--- a/drivers/infiniband/core/cache.c
+++ b/drivers/infiniband/core/cache.c
@@ -121,15 +121,16 @@ static int write_gid(struct ib_device *ib_dev, u8 port,
 {
        int ret = 0;
        struct net_device *old_net_dev;
+       unsigned long flags;
 
        /* in rdma_cap_roce_gid_table, this funciton should be protected by a
         * sleep-able lock.
         */
-       write_lock(&table->data_vec[ix].lock);
+       write_lock_irqsave(&table->data_vec[ix].lock, flags);
 
        if (rdma_cap_roce_gid_table(ib_dev, port)) {
                table->data_vec[ix].props |= GID_TABLE_ENTRY_INVALID;
-               write_unlock(&table->data_vec[ix].lock);
+               write_unlock_irqrestore(&table->data_vec[ix].lock, flags);
                /* GID_TABLE_WRITE_ACTION_MODIFY currently isn't supported by
                 * RoCE providers and thus only updates the cache.
                 */
@@ -139,7 +140,7 @@ static int write_gid(struct ib_device *ib_dev, u8 port,
                else if (action == GID_TABLE_WRITE_ACTION_DEL)
                        ret = ib_dev->del_gid(ib_dev, port, ix,
                                              &table->data_vec[ix].context);
-               write_lock(&table->data_vec[ix].lock);
+               write_lock_irqsave(&table->data_vec[ix].lock, flags);
        }
 
        old_net_dev = table->data_vec[ix].attr.ndev;
@@ -161,7 +162,7 @@ static int write_gid(struct ib_device *ib_dev, u8 port,
 
        table->data_vec[ix].props &= ~GID_TABLE_ENTRY_INVALID;
 
-       write_unlock(&table->data_vec[ix].lock);
+       write_unlock_irqrestore(&table->data_vec[ix].lock, flags);
 
        if (!ret && rdma_cap_roce_gid_table(ib_dev, port)) {
                struct ib_event event;
-- 
2.1.0

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