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authorChuck Lever <chuck.lever@oracle.com>2010-12-24 02:32:32 +0100
committerTrond Myklebust <Trond.Myklebust@netapp.com>2011-01-06 20:47:56 +0100
commitfca5238ef3232cd0cf4bf0457e751b3bb20912a9 (patch)
tree5b61da0d71e3e89b835d46a49e0f4945b5002cea /fs/nfs/nfs4renewd.c
parentpnfs: layout roc code (diff)
downloadlinux-fca5238ef3232cd0cf4bf0457e751b3bb20912a9.tar.xz
linux-fca5238ef3232cd0cf4bf0457e751b3bb20912a9.zip
NFS: Allow walking nfs_client.cl_superblocks list outside client.c
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> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4renewd.c')
-rw-r--r--fs/nfs/nfs4renewd.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
index 72b6c580af13..cde5650ee5a2 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;