[PATCH Bakeathon version 2 1/1] NFSv4.1: fix hlist_del in _deviceid_purge_client

[andros@netapp.com]

From: Andy Adamson <andros@netapp.com>

Signed-off-by: Andy Adamson <andros@netapp.com>
cc:stable@kernel.org [2.6.39]
---
 fs/nfs/inode.c    |    2 ++
 fs/nfs/pnfs.h     |    1 +
 fs/nfs/pnfs_dev.c |   14 +++++++++++++-
 3 files changed, 16 insertions(+), 1 deletions(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 6f4850d..55ba1b0 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1595,6 +1595,8 @@ static int __init init_nfs_fs(void)
 	if (err)
 		goto out0;
 
+	nfs4_init_deviceid_cache();
+
 #ifdef CONFIG_PROC_FS
 	rpc_proc_register(&nfs_rpcstat);
 #endif
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index e46edac..67400bc 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -212,6 +212,7 @@ void nfs4_init_deviceid_node(struct nfs4_deviceid_node *,
 struct nfs4_deviceid_node *nfs4_insert_deviceid_node(struct nfs4_deviceid_node *);
 bool nfs4_put_deviceid_node(struct nfs4_deviceid_node *);
 void nfs4_deviceid_purge_client(const struct nfs_client *);
+void nfs4_init_deviceid_cache(void);
 
 static inline int lo_fail_bit(u32 iomode)
 {
diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c
index 037a5c6..923a9da 100644
--- a/fs/nfs/pnfs_dev.c
+++ b/fs/nfs/pnfs_dev.c
@@ -161,6 +161,15 @@ nfs4_init_deviceid_node(struct nfs4_deviceid_node *d,
 }
 EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
 
+void
+nfs4_init_deviceid_cache()
+{
+	long h;
+
+	for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
+		INIT_HLIST_HEAD(&nfs4_deviceid_cache[h]);
+}
+
 /*
  * Uniquely initialize and insert a deviceid node into cache
  *
@@ -236,9 +245,10 @@ _deviceid_purge_client(const struct nfs_client *clp, long hash)
 
 	synchronize_rcu();
 	while (!hlist_empty(&tmp)) {
+		d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
+		hlist_del_init(&d->tmpnode);
 		if (atomic_dec_and_test(&d->ref))
 			d->ld->free_deviceid_node(d);
-		hlist_del_init(&d->tmpnode);
 	}
 }
 
@@ -247,6 +257,8 @@ nfs4_deviceid_purge_client(const struct nfs_client *clp)
 {
 	long h;
 
+	if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
+		return;
 	for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
 		_deviceid_purge_client(clp, h);
 }
-- 
1.7.3.1