Re :statfs() gives ESTALE error

[Menyhart Zoltan <Zoltan.Menyhart@bull.net>]

[-- Attachment #1: Type: text/plain, Size: 695 bytes --]

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 option 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.

Signed-off-by: Zoltan Menyhart  <Zoltan.Menyhart@bull.net>

[-- Attachment #2: nfs_statfs.patch --]
[-- Type: text/x-patch, Size: 595 bytes --]

diff -Nru linux-2.6.36-rc3-orig/fs/nfs/super.c linux-2.6.36-rc3-new/fs/nfs/super.c
--- linux-2.6.36-rc3-orig/fs/nfs/super.c	2010-08-29 17:36:04.000000000 +0200
+++ linux-2.6.36-rc3-new/fs/nfs/super.c	2010-09-08 11:33:03.078684569 +0200
@@ -431,7 +431,15 @@
 		goto out_err;
 
 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
+	if (unlikely(error == -ESTALE)) {
 
+		struct dentry *pd_dentry;
+
+		if ((pd_dentry = dget_parent(dentry)) != NULL) {
+			nfs_zap_caches(pd_dentry->d_inode);
+			dput(pd_dentry);
+		}
+	}
 	nfs_free_fattr(res.fattr);
 	if (error < 0)
 		goto out_err;