Message-ID: <4C7F4AB7.5020802@bull.net>
Date: Thu, 02 Sep 2010 08:56:55 +0200
From: Menyhart Zoltan <Zoltan.Menyhart@bull.net>
To: linux-nfs@vger.kernel.org
Subject: statfs() gives ESTALE error
References: <4C7E4469.70807@duchatelet.net>
In-Reply-To: <4C7E4469.70807@duchatelet.net>
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Sender: linux-nfs-owner@vger.kernel.org
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Hi,

An NFS client executes a statfs("file", &buff) call.
"file" exists / existed, the client has read / written it,
but it has already closed it.

user_path(pathname, &path) looks up "file" successfully in the
directory-cache  and restarts the aging timer of the directory-entry.
Even if "file" has already been removed from the server, because the
lookupcache=positive opcion I use, keeps the entries valid for a while.

nfs_statfs() returns ESTALE if "file" has already been removed from the
server.

If the user application repeats the statfs("file", &buff) call, we
are stuck: "file" remains young forever in the directory-cache.

Should not this directory-entry be cleaned up?

--- linux-2.6.32.x86_64-orig/fs/nfs/super.c     2010-08-02 14:34:57.000000000 +0200
+++ linux-2.6.32.x86_64/fs/nfs/super.c  2010-08-31 16:57:30.000000000 +0200
@@ -429,6 +429,22 @@
         int error;
  
         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
+       if (unlikely(error == -ESTALE)){
+
+               struct inode *pd_inode;
+
+               BUG_ON(dentry->d_parent == NULL);
+               pd_inode = dentry->d_parent->d_inode;
+               BUG_ON(pd_inode == NULL);
+               /*
+                * This forces the revalidation code in nfs_lookup_revalidate() to do a
+                * full lookup on all child dentries of 'dir' whenever a change occurs
+                * on the server that might have invalidated our dcache.
+                */
+               spin_lock(&pd_inode->i_lock);
+               nfs_force_lookup_revalidate(pd_inode);
+               spin_unlock(&pd_inode->i_lock);
+       }
         if (error < 0)
                 goto out_err;
         buf->f_type = NFS_SUPER_MAGIC;

It's for the 2.6.32, yet the 2.6.36 dos not change from this aspect.

Thanks,

Zoltan Menyhart