NFS: handle inode==NULL in __put_nfs_open_context

inode may be NULL when put_nfs_open_context is called from nfs_atomic_lookup
before d_add_unique(dentry, inode)

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 2ff814272dcf..702ed096e790 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -654,11 +654,14 @@ static void __put_nfs_open_context(struct nfs_open_context *ctx, int is_sync)
 {
         struct inode *inode = ctx->path.dentry->d_inode;
 
-        if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
+        if (inode) {
+                if (!atomic_dec_and_lock(&ctx->lock_context.count, &inode->i_lock))
+                        return;
+                list_del(&ctx->list);
+                spin_unlock(&inode->i_lock);
+                NFS_PROTO(inode)->close_context(ctx, is_sync);
+        } else if (!atomic_dec_and_test(&ctx->lock_context.count))
                 return;
-        list_del(&ctx->list);
-        spin_unlock(&inode->i_lock);
-        NFS_PROTO(inode)->close_context(ctx, is_sync);
         if (ctx->cred != NULL)
                 put_rpccred(ctx->cred);
         path_put(&ctx->path);