[PATCH v2 07/16] sunrpc: factor svc_rqst allocation and freeing from sv_nrthreads refcounting

From: Jeff Layton
Date: Wed Dec 10 2014 - 14:11:52 EST


In later patches, we'll want to be able to allocate and free svc_rqst
structures without monkeying with the serv->sv_nrthreads refcount.

Factor those pieces out of their respective functions.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxxxxxxx>
---
include/linux/sunrpc/svc.h | 3 +++
net/sunrpc/svc.c | 58 ++++++++++++++++++++++++++++++----------------
2 files changed, 41 insertions(+), 20 deletions(-)

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 28e5f5716a87..3d2113222dda 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -458,8 +458,11 @@ void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net);
int svc_bind(struct svc_serv *serv, struct net *net);
struct svc_serv *svc_create(struct svc_program *, unsigned int,
struct svc_serv_ops *);
+struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv,
+ struct svc_pool *pool, int node);
struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
struct svc_pool *pool, int node);
+void svc_rqst_free(struct svc_rqst *);
void svc_exit_thread(struct svc_rqst *);
unsigned int svc_pool_map_get(void);
void svc_pool_map_put(void);
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 04c083a53121..165fa1803a0a 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -583,40 +583,52 @@ svc_release_buffer(struct svc_rqst *rqstp)
}

struct svc_rqst *
-svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
+svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node)
{
struct svc_rqst *rqstp;

rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node);
if (!rqstp)
- goto out_enomem;
+ return rqstp;

- serv->sv_nrthreads++;
__set_bit(RQ_BUSY, &rqstp->rq_flags);
spin_lock_init(&rqstp->rq_lock);
rqstp->rq_server = serv;
rqstp->rq_pool = pool;
- spin_lock_bh(&pool->sp_lock);
- pool->sp_nrthreads++;
- list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
- spin_unlock_bh(&pool->sp_lock);

rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
if (!rqstp->rq_argp)
- goto out_thread;
+ goto out_enomem;

rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
if (!rqstp->rq_resp)
- goto out_thread;
+ goto out_enomem;

if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
- goto out_thread;
+ goto out_enomem;

return rqstp;
-out_thread:
- svc_exit_thread(rqstp);
out_enomem:
- return ERR_PTR(-ENOMEM);
+ svc_rqst_free(rqstp);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(svc_rqst_alloc);
+
+struct svc_rqst *
+svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
+{
+ struct svc_rqst *rqstp;
+
+ rqstp = svc_rqst_alloc(serv, pool, node);
+ if (!rqstp)
+ return ERR_PTR(-ENOMEM);
+
+ serv->sv_nrthreads++;
+ spin_lock_bh(&pool->sp_lock);
+ pool->sp_nrthreads++;
+ list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
+ spin_unlock_bh(&pool->sp_lock);
+ return rqstp;
}
EXPORT_SYMBOL_GPL(svc_prepare_thread);

@@ -747,19 +759,25 @@ svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
EXPORT_SYMBOL_GPL(svc_set_num_threads);

/*
- * Called from a server thread as it's exiting. Caller must hold the BKL or
- * the "service mutex", whichever is appropriate for the service.
+ * Called from a server thread as it's exiting. Caller must hold the service's
+ * mutex.
*/
void
-svc_exit_thread(struct svc_rqst *rqstp)
+svc_rqst_free(struct svc_rqst *rqstp)
{
- struct svc_serv *serv = rqstp->rq_server;
- struct svc_pool *pool = rqstp->rq_pool;
-
svc_release_buffer(rqstp);
kfree(rqstp->rq_resp);
kfree(rqstp->rq_argp);
kfree(rqstp->rq_auth_data);
+ kfree_rcu(rqstp, rq_rcu_head);
+}
+EXPORT_SYMBOL_GPL(svc_rqst_free);
+
+void
+svc_exit_thread(struct svc_rqst *rqstp)
+{
+ struct svc_serv *serv = rqstp->rq_server;
+ struct svc_pool *pool = rqstp->rq_pool;

spin_lock_bh(&pool->sp_lock);
pool->sp_nrthreads--;
@@ -767,7 +785,7 @@ svc_exit_thread(struct svc_rqst *rqstp)
list_del_rcu(&rqstp->rq_all);
spin_unlock_bh(&pool->sp_lock);

- kfree_rcu(rqstp, rq_rcu_head);
+ svc_rqst_free(rqstp);

/* Release the server */
if (serv)
--
2.1.0

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