From: Chuck Lever <chuck.lever@oracle.com>
To: trond.myklebust@netapp.com
Cc: linux-nfs@vger.kernel.org
Subject: [PATCH 1/4] NFS: Allow walking nfs_client.cl_superblocks list outside client.c
Date: Thu, 23 Dec 2010 20:32:32 -0500 [thread overview]
Message-ID: <20101224013232.2445.72763.stgit@matisse.1015granger.net> (raw)
In-Reply-To: <20101224012636.2445.41411.stgit@matisse.1015granger.net>
We're about to move some fields from struct nfs_client to struct
nfs_server. There is a many-to-one relationship between nfs_servers
and nfs_clients. After these fields are moved to the nfs_server
struct, to visit all of the data in these fields that is owned by one
nfs_client, code will need to visit each nfs_server on the
cl_superblocks list for that nfs_client.
To serialize changes to the cl_superblocks list during these little
expeditions, protect the list with RCU.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
fs/nfs/client.c | 44 +++++++++++++++++++++++++-------------------
fs/nfs/nfs4renewd.c | 9 +++++++--
2 files changed, 32 insertions(+), 21 deletions(-)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 0870d0d..05e2ee2 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -988,6 +988,27 @@ static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_serve
target->options = source->options;
}
+static void nfs_server_insert_lists(struct nfs_server *server)
+{
+ struct nfs_client *clp = server->nfs_client;
+
+ spin_lock(&nfs_client_lock);
+ list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);
+ list_add_tail(&server->master_link, &nfs_volume_list);
+ spin_unlock(&nfs_client_lock);
+
+}
+
+static void nfs_server_remove_lists(struct nfs_server *server)
+{
+ spin_lock(&nfs_client_lock);
+ list_del_rcu(&server->client_link);
+ list_del(&server->master_link);
+ spin_unlock(&nfs_client_lock);
+
+ synchronize_rcu();
+}
+
/*
* Allocate and initialise a server record
*/
@@ -1029,11 +1050,8 @@ void nfs_free_server(struct nfs_server *server)
{
dprintk("--> nfs_free_server()\n");
+ nfs_server_remove_lists(server);
unset_pnfs_layoutdriver(server);
- spin_lock(&nfs_client_lock);
- list_del(&server->client_link);
- list_del(&server->master_link);
- spin_unlock(&nfs_client_lock);
if (server->destroy != NULL)
server->destroy(server);
@@ -1108,11 +1126,7 @@ struct nfs_server *nfs_create_server(const struct nfs_parsed_mount_data *data,
(unsigned long long) server->fsid.major,
(unsigned long long) server->fsid.minor);
- spin_lock(&nfs_client_lock);
- list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
- list_add_tail(&server->master_link, &nfs_volume_list);
- spin_unlock(&nfs_client_lock);
-
+ nfs_server_insert_lists(server);
server->mount_time = jiffies;
nfs_free_fattr(fattr);
return server;
@@ -1342,11 +1356,7 @@ static int nfs4_server_common_setup(struct nfs_server *server,
if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
server->namelen = NFS4_MAXNAMLEN;
- spin_lock(&nfs_client_lock);
- list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
- list_add_tail(&server->master_link, &nfs_volume_list);
- spin_unlock(&nfs_client_lock);
-
+ nfs_server_insert_lists(server);
server->mount_time = jiffies;
out:
nfs_free_fattr(fattr);
@@ -1551,11 +1561,7 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source,
if (error < 0)
goto out_free_server;
- spin_lock(&nfs_client_lock);
- list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
- list_add_tail(&server->master_link, &nfs_volume_list);
- spin_unlock(&nfs_client_lock);
-
+ nfs_server_insert_lists(server);
server->mount_time = jiffies;
nfs_free_fattr(fattr_fsinfo);
diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
index 72b6c58..cde5650 100644
--- a/fs/nfs/nfs4renewd.c
+++ b/fs/nfs/nfs4renewd.c
@@ -63,9 +63,14 @@ nfs4_renew_state(struct work_struct *work)
ops = clp->cl_mvops->state_renewal_ops;
dprintk("%s: start\n", __func__);
- /* Are there any active superblocks? */
- if (list_empty(&clp->cl_superblocks))
+
+ rcu_read_lock();
+ if (list_empty(&clp->cl_superblocks)) {
+ rcu_read_unlock();
goto out;
+ }
+ rcu_read_unlock();
+
spin_lock(&clp->cl_lock);
lease = clp->cl_lease_time;
last = clp->cl_last_renewal;
next prev parent reply other threads:[~2010-12-24 1:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-24 1:32 [PATCH 0/4] Refactor data structures to support NFSv4 migration (2) Chuck Lever
2010-12-24 1:32 ` Chuck Lever [this message]
2010-12-24 1:32 ` [PATCH 2/4] NFS: Move cl_state_owners and related fields to the nfs_server struct Chuck Lever
2010-12-24 1:32 ` [PATCH 3/4] NFS: Introduce nfs_detach_delegations() Chuck Lever
2010-12-24 1:33 ` [PATCH 4/4] NFS: Move cl_delegations to the nfs_server struct Chuck Lever
[not found] ` <20101224012636.2445.41411.stgit-RytpoXr2tKZ9HhUboXbp9zCvJB+x5qRC@public.gmane.org>
2011-03-04 22:45 ` [PATCH 0/4] Refactor data structures to support NFSv4 migration (2) Frank Filz
[not found] ` <1299278738.5341.0.camel-LVD8ZR29O+mrIzol8Bc5pA@public.gmane.org>
2011-03-04 22:57 ` Chuck Lever
-- strict thread matches above, loose matches on Subject: below --
2010-12-23 21:54 [PATCH 0/4] Refactor data structures to support NFSv4 migration Chuck Lever
2010-12-23 21:54 ` [PATCH 1/4] NFS: Allow walking nfs_client.cl_superblocks list outside client.c Chuck Lever
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