Attachment 294274 Details for Bug 428720 – patch -- when truncating a readdir reply and setting EOF return -EIO

[patch] patch -- when truncating a readdir reply and setting EOF return -EIO

0001-NFS-have-short-READDIR-replies-return-EIO.patch (text/plain), 2.12 KB, created by Jeff Layton on 2008-02-07 21:48:02 UTC

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Creator: Jeff Layton

Created: 2008-02-07 21:48:02 UTC

Size: 2.12 KB

patch

obsolete

>From 836e756c20ab1bd3e7aed0ddc1b7570d64c6cd07 Mon Sep 17 00:00:00 2001
>From: Jeff Layton <jlayton@redhat.com>
>Date: Thu, 7 Feb 2008 08:34:22 -0500
>Subject: [PATCH] NFS: have short READDIR replies return -EIO
>
>Recently, I ran across a server-side bug that caused the server to send
>truncated READDIR replies. The server would send a valid RPC response to
>a READDIR call, but the contents of it were basically missing
>(everything after the status).
>
>This problem had long been patched in mainline kernels, but the
>interesting bit was that newer clients didn't return an error in this
>situation.  The XDR decoders for readdir calls are supposed to check the
>validity of the response, but in this situation it just fudges the
>contents of the pagecache to make it look like a completely empty
>directory.
>
>Shouldn't the client return an error in this situation? The response
>obviously isn't valid so it seems like it shouldn't pretend that it is.
>If so, would the following patch make sense?
>
>Signed-off-by: Jeff Layton <jlayton@redhat.com>
>---
> fs/nfs/nfs2xdr.c |    1 +
> fs/nfs/nfs3xdr.c |    1 +
> fs/nfs/nfs4xdr.c |    1 +
> 3 files changed, 3 insertions(+), 0 deletions(-)
>
>diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
>index 1f7ea67..aa6966a 100644
>--- a/fs/nfs/nfs2xdr.c
>+++ b/fs/nfs/nfs2xdr.c
>@@ -478,6 +478,7 @@ nfs_xdr_readdirres(struct rpc_rqst *req, __be32 *p, void *dummy)
> 	if (!nr) {
> 		dprintk("NFS: readdir reply truncated!\n");
> 		entry[1] = 1;
>+		nr = -errno_NFSERR_IO;
> 	}
> 	goto out;
> err_unmap:
>diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
>index 3917e2f..04ba525 100644
>--- a/fs/nfs/nfs3xdr.c
>+++ b/fs/nfs/nfs3xdr.c
>@@ -592,6 +592,7 @@ nfs3_xdr_readdirres(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirres *res
> 	if (!nr) {
> 		dprintk("NFS: readdir reply truncated!\n");
> 		entry[1] = 1;
>+		nr = -errno_NFSERR_IO;
> 	}
> 	goto out;
> err_unmap:
>diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
>index db1ed9c..139c9e1 100644
>--- a/fs/nfs/nfs4xdr.c
>+++ b/fs/nfs/nfs4xdr.c
>@@ -3544,6 +3544,7 @@ short_pkt:
> 	if (!nr) {
> 		dprintk("NFS: readdir reply truncated!\n");
> 		entry[1] = 1;
>+		nr = -errno_NFSERR_IO;
> 	}
> 	goto out;
> err_unmap:
>-- 
>1.5.3.8
>

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Attachments on bug 428720: 294274 | 303350 | 303352 | 303353