[lustre-devel] [PATCH 22/32] lustre: ptlrpc: simplify locking in ptlrpc_add_rqs_to_pool()

NeilBrown neilb at suse.com
Wed Mar 13 17:11:51 PDT 2019

This spinlock is only needed in this function to
protect the list_add_tail(), so make that more

This change means that prp_rq_size is set outside of the spinlock, but
as it is only ever read outside of the spinlock, that cannot matter.

Signed-off-by: NeilBrown <neilb at suse.com>
 drivers/staging/lustre/lustre/ptlrpc/client.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/staging/lustre/lustre/ptlrpc/client.c b/drivers/staging/lustre/lustre/ptlrpc/client.c
index baf2b05e2f5c..2514a142e799 100644
--- a/drivers/staging/lustre/lustre/ptlrpc/client.c
+++ b/drivers/staging/lustre/lustre/ptlrpc/client.c
@@ -521,13 +521,11 @@ int ptlrpc_add_rqs_to_pool(struct ptlrpc_request_pool *pool, int num_rq)
 		 "Trying to change pool size with nonempty pool from %d to %d bytes\n",
 		 pool->prp_rq_size, size);
-	spin_lock(&pool->prp_lock);
 	pool->prp_rq_size = size;
 	for (i = 0; i < num_rq; i++) {
 		struct ptlrpc_request *req;
 		struct lustre_msg *msg;
-		spin_unlock(&pool->prp_lock);
 		req = ptlrpc_request_cache_alloc(GFP_KERNEL);
 		if (!req)
 			return i;
@@ -541,8 +539,8 @@ int ptlrpc_add_rqs_to_pool(struct ptlrpc_request_pool *pool, int num_rq)
 		req->rq_pool = pool;
 		list_add_tail(&req->rq_list, &pool->prp_req_list);
+		spin_unlock(&pool->prp_lock);
-	spin_unlock(&pool->prp_lock);
 	return num_rq;

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