From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
XArray uses internal lock for updates to XArray. This means that our
external RW lock is needed to ensure that entry is not deleted while
we are performing iteration over list.
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
drivers/infiniband/core/restrack.c | 2 --
include/rdma/restrack.h | 3 ++-
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/core/restrack.c b/drivers/infiniband/core/restrack.c
index ac97167da81c..076ef6475df8 100644
--- a/drivers/infiniband/core/restrack.c
+++ b/drivers/infiniband/core/restrack.c
@@ -210,13 +210,11 @@ static void rdma_restrack_add(struct rdma_restrack_entry *res)
kref_init(&res->kref);
init_completion(&res->comp);
- down_write(&dev->res.rwsem);
ret = rt_xa_alloc_cyclic(&dev->res.xa[res->type], &res->id, res,
&dev->res.next_id[res->type]);
if (!ret)
res->valid = true;
- up_write(&dev->res.rwsem);
}
/**
diff --git a/include/rdma/restrack.h b/include/rdma/restrack.h
index 44ce32cc0b51..53e1a7fb7355 100644
--- a/include/rdma/restrack.h
+++ b/include/rdma/restrack.h
@@ -58,7 +58,8 @@ struct rdma_restrack_entry;
*/
struct rdma_restrack_root {
/*
- * @rwsem: Read/write lock to protect lists
+ * @rwsem: Read/write lock to protect erase of entry.
+ * Lists and insertions are protected by XArray internal lock.
*/
struct rw_semaphore rwsem;
/**
--
2.19.1
