linux-kernel - [PATCH v4 02/10] NFS: callback service creation function introduced

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20120820140011.17404.7429.stgit@localhost.localdomain>
Date:	Mon, 20 Aug 2012 18:00:11 +0400
From:	Stanislav Kinsbursky <skinsbursky@...allels.com>
To:	Trond.Myklebust@...app.com
Cc:	bfields@...ldses.org, linux-nfs@...r.kernel.org,
	linux-kernel@...r.kernel.org, devel@...nvz.org
Subject: [PATCH v4 02/10] NFS: callback service creation function introduced

This function creates service if it's not exist, or increase usage counter of
the existent, and returns pointer to it.
Usage counter will be droppepd by svc_destroy() later in nfs_callback_up().

Signed-off-by: Stanislav Kinsbursky <skinsbursky@...allels.com>
---
 fs/nfs/callback.c |   63 +++++++++++++++++++++++++++++++++++++++++------------
 1 files changed, 49 insertions(+), 14 deletions(-)

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 51297b2..18efeb5 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -217,12 +217,50 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
 }
 #endif /* CONFIG_NFS_V4_1 */
 
+static struct svc_serv *nfs_callback_create_svc(int minorversion)
+{
+	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
+	struct svc_serv *serv;
+
+	/*
+	 * Check whether we're already up and running.
+	 */
+	if (cb_info->task) {
+		/*
+		 * Note: increase service usage, because later in case of error
+		 * svc_destroy() will be called.
+		 */
+		svc_get(cb_info->serv);
+		return cb_info->serv;
+	}
+
+	/*
+	 * Sanity check: if there's no task,
+	 * we should be the first user ...
+	 */
+	if (cb_info->users)
+		printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
+			cb_info->users);
+
+	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
+	if (!serv) {
+		printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	/* As there is only one thread we need to over-ride the
+	 * default maximum of 80 connections
+	 */
+	serv->sv_maxconn = 1024;
+	dprintk("nfs_callback_create_svc: service created\n");
+	return serv;
+}
+
 /*
  * Bring up the callback thread if it is not already up.
  */
 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 {
-	struct svc_serv *serv = NULL;
+	struct svc_serv *serv;
 	struct svc_rqst *rqstp;
 	int (*callback_svc)(void *vrqstp);
 	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
@@ -232,19 +270,17 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 	struct net *net = &init_net;
 
 	mutex_lock(&nfs_callback_mutex);
+
+	serv = nfs_callback_create_svc(minorversion);
+	if (IS_ERR(serv)) {
+		ret = PTR_ERR(serv);
+		goto err_create;
+	}
+
 	if (cb_info->users++ || cb_info->task != NULL) {
 		nfs_callback_bc_serv(minorversion, xprt, cb_info);
 		goto out;
 	}
-	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
-	if (!serv) {
-		ret = -ENOMEM;
-		goto out_err;
-	}
-	/* As there is only one thread we need to over-ride the
-	 * default maximum of 80 connections
-	 */
-	serv->sv_maxconn = 1024;
 
 	ret = svc_bind(serv, net);
 	if (ret < 0) {
@@ -285,16 +321,15 @@ out:
 	 * on both success and failure so that the refcount is 1 when the
 	 * thread exits.
 	 */
-	if (serv)
-		svc_destroy(serv);
+	svc_destroy(serv);
+err_create:
 	mutex_unlock(&nfs_callback_mutex);
 	return ret;
 out_err:
 	dprintk("NFS: Couldn't create callback socket or server thread; "
 		"err = %d\n", ret);
 	cb_info->users--;
-	if (serv)
-		svc_shutdown_net(serv, net);
+	svc_shutdown_net(serv, net);
 	goto out;
 }
 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/