Re: [PATCH] Reinstantiating stale inodes

[Steve Dickson <SteveD@redhat.com>]

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Steve Dickson wrote:

> Here is a 2.4 patch that will reinstantiate an inode
> when a ESTALE error is returned on a getattr. When
> the error occurs, a lookup is immediately issued
> to get a new fh.
>
> The fixes the problem of a server rsync -a directory
> that a client has mounted. The key being the -a flag
> since it causes the server not to update the mtime on
> the directory.

It turns out there is a much easier and simpler (safer)
way to reinstantiate inodes than my original patch.

Realizing only parts of an inode needed to be reinstantiated
not the entire thing, this second patch only reinstantiates
two parts of the inode (i.e. fhandle and fattrs) instead of the
entire inode like my original patch did.

I had to export the new nfs_reinstantiate() function because
the ACL code needs to use it, so things like ls -l will work....

Comments? Is this something Marcelo might be interested in?

SteveD.







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--- linux-2.4.21/fs/nfs/inode.c.org	2004-04-17 18:26:32.000000000 -0400
+++ linux-2.4.21/fs/nfs/inode.c	2004-05-01 11:11:12.000000000 -0400
@@ -953,13 +953,48 @@ nfs_wait_on_inode(struct inode *inode, i
 }
 
 /*
+ * Reinstantiate an inode that has gone stale
+ */
+int
+nfs_reinstantiate(struct dentry *dentry)
+{
+	int error;
+	struct nfs_fh fhandle;
+	struct inode *dir = dentry->d_parent->d_inode;
+	struct inode *inode = dentry->d_inode;
+	struct nfs_fattr fattr;
+
+	nfs_zap_caches(dir);
+	nfs_zap_caches(inode);
+
+	error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
+	if (!error) {
+		memcpy(&inode->u.nfs_i.fh, &fhandle, sizeof(struct nfs_fh));
+		nfs_refresh_inode(inode, &fattr);
+	}
+
+	return error;
+}
+
+/*
  * Externally visible revalidation function
  */
 int
 nfs_revalidate(struct dentry *dentry)
 {
 	struct inode *inode = dentry->d_inode;
-	return nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	int error;
+
+	error = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	if (!error || error != -ESTALE)
+		return error;
+	/*
+	 * We have a stale fh so ask the server for another one
+	 */
+	if (nfs_reinstantiate(dentry) == 0)
+		error = 0;
+
+	return error;
 }
 
 /*
--- linux-2.4.21/include/linux/nfs_fs.h.org	2004-04-17 18:40:02.000000000 -0400
+++ linux-2.4.21/include/linux/nfs_fs.h	2004-05-01 10:55:59.000000000 -0400
@@ -159,6 +159,7 @@ extern struct inode *nfs_fhget(struct de
 				struct nfs_fattr *);
 extern int __nfs_refresh_inode(struct inode *, struct nfs_fattr *);
 extern int nfs_revalidate(struct dentry *);
+extern int nfs_reinstantiate(struct dentry *);
 extern int nfs_permission(struct inode *, int);
 extern int nfs_open(struct inode *, struct file *);
 extern int nfs_release(struct inode *, struct file *);