linux-kernel - [PATCH 5.18 0883/1095] 9p: Drop kref usage

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Message-Id: <20220815180505.870121290@linuxfoundation.org>
Date:   Mon, 15 Aug 2022 20:04:42 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Kent Overstreet <kent.overstreet@...il.com>,
        Eric Van Hensbergen <ericvh@...il.com>,
        Latchesar Ionkov <lucho@...kov.net>,
        Dominique Martinet <asmadeus@...ewreck.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.18 0883/1095] 9p: Drop kref usage

From: Kent Overstreet <kent.overstreet@...il.com>

[ Upstream commit 6cda12864cb0f99810a5809e11e3ee5b102c9a47 ]

An upcoming patch is going to require passing the client through
p9_req_put() -> p9_req_free(), but that's awkward with the kref
indirection - so this patch switches to using refcount_t directly.

Link: https://lkml.kernel.org/r/20220704014243.153050-1-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@...il.com>
Cc: Eric Van Hensbergen <ericvh@...il.com>
Cc: Latchesar Ionkov <lucho@...kov.net>
Signed-off-by: Dominique Martinet <asmadeus@...ewreck.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 include/net/9p/client.h |  6 +++---
 net/9p/client.c         | 19 ++++++++-----------
 2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index ec1d1706f43c..c038c2d73dae 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -76,7 +76,7 @@ enum p9_req_status_t {
 struct p9_req_t {
 	int status;
 	int t_err;
-	struct kref refcount;
+	refcount_t refcount;
 	wait_queue_head_t wq;
 	struct p9_fcall tc;
 	struct p9_fcall rc;
@@ -227,12 +227,12 @@ struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag);
 
 static inline void p9_req_get(struct p9_req_t *r)
 {
-	kref_get(&r->refcount);
+	refcount_inc(&r->refcount);
 }
 
 static inline int p9_req_try_get(struct p9_req_t *r)
 {
-	return kref_get_unless_zero(&r->refcount);
+	return refcount_inc_not_zero(&r->refcount);
 }
 
 int p9_req_put(struct p9_req_t *r);
diff --git a/net/9p/client.c b/net/9p/client.c
index 8bba0d9cf975..0ee48e8b7220 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -305,7 +305,7 @@ p9_tag_alloc(struct p9_client *c, int8_t type, unsigned int max_size)
 	 * callback), so p9_client_cb eats the second ref there
 	 * as the pointer is duplicated directly by virtqueue_add_sgs()
 	 */
-	refcount_set(&req->refcount.refcount, 2);
+	refcount_set(&req->refcount, 2);
 
 	return req;
 
@@ -370,18 +370,15 @@ static int p9_tag_remove(struct p9_client *c, struct p9_req_t *r)
 	return p9_req_put(r);
 }
 
-static void p9_req_free(struct kref *ref)
-{
-	struct p9_req_t *r = container_of(ref, struct p9_req_t, refcount);
-
-	p9_fcall_fini(&r->tc);
-	p9_fcall_fini(&r->rc);
-	kmem_cache_free(p9_req_cache, r);
-}
-
 int p9_req_put(struct p9_req_t *r)
 {
-	return kref_put(&r->refcount, p9_req_free);
+	if (refcount_dec_and_test(&r->refcount)) {
+		p9_fcall_fini(&r->tc);
+		p9_fcall_fini(&r->rc);
+		kmem_cache_free(p9_req_cache, r);
+		return 1;
+	}
+	return 0;
 }
 EXPORT_SYMBOL(p9_req_put);
 
-- 
2.35.1