From 7c81100128e8e15f26e722bbde8629cd197f811f Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@redhat.com>
Date: Fri, 22 Feb 2008 14:50:01 -0500
Subject: [PATCH] --- yaml --- r: 92887 b: refs/heads/master c:
 7bda2cdf484a00e52b0ed925e99d4bf4696b2c7a h: refs/heads/master i:   92885:
 01a5b8b8eb8df6df7759c0d8981534291c51bd20   92883:
 313ccc84c4240999a979169c4f482b96285789ff   92879:
 493ac08b21a2ba38e6b21396ad61fdd117e60f5c v: v3

---
 [refs]                 |  2 +-
 trunk/fs/nfs/nfs4xdr.c | 37 +++++++++++++++++++++++++++----------
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/[refs] b/[refs]
index 4dc27f0fc7ba..89100c3c8591 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 643f81115baca3630e544f6874567648b605efae
+refs/heads/master: 7bda2cdf484a00e52b0ed925e99d4bf4696b2c7a
diff --git a/trunk/fs/nfs/nfs4xdr.c b/trunk/fs/nfs/nfs4xdr.c
index 37421dd4805d..2b519f6325f9 100644
--- a/trunk/fs/nfs/nfs4xdr.c
+++ b/trunk/fs/nfs/nfs4xdr.c
@@ -3481,7 +3481,7 @@ static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct n
 	size_t		hdrlen;
 	u32		recvd, pglen = rcvbuf->page_len;
 	__be32		*end, *entry, *p, *kaddr;
-	unsigned int	nr;
+	unsigned int	nr = 0;
 	int		status;
 
 	status = decode_op_hdr(xdr, OP_READDIR);
@@ -3505,7 +3505,12 @@ static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct n
 	kaddr = p = kmap_atomic(page, KM_USER0);
 	end = p + ((pglen + readdir->pgbase) >> 2);
 	entry = p;
-	for (nr = 0; *p++; nr++) {
+
+	/* Make sure the packet actually has a value_follows and EOF entry */
+	if ((entry + 1) > end)
+		goto short_pkt;
+
+	for (; *p++; nr++) {
 		u32 len, attrlen, xlen;
 		if (end - p < 3)
 			goto short_pkt;
@@ -3532,20 +3537,32 @@ static int decode_readdir(struct xdr_stream *xdr, struct rpc_rqst *req, struct n
 		p += attrlen;		/* attributes */
 		entry = p;
 	}
-	if (!nr && (entry[0] != 0 || entry[1] == 0))
-		goto short_pkt;
+	/*
+	 * Apparently some server sends responses that are a valid size, but
+	 * contain no entries, and have value_follows==0 and EOF==0. For
+	 * those, just set the EOF marker.
+	 */
+	if (!nr && entry[1] == 0) {
+		dprintk("NFS: readdir reply truncated!\n");
+		entry[1] = 1;
+	}
 out:	
 	kunmap_atomic(kaddr, KM_USER0);
 	return 0;
 short_pkt:
+	/*
+	 * When we get a short packet there are 2 possibilities. We can
+	 * return an error, or fix up the response to look like a valid
+	 * response and return what we have so far. If there are no
+	 * entries and the packet was short, then return -EIO. If there
+	 * are valid entries in the response, return them and pretend that
+	 * the call was successful, but incomplete. The caller can retry the
+	 * readdir starting at the last cookie.
+	 */
 	dprintk("%s: short packet at entry %d\n", __FUNCTION__, nr);
 	entry[0] = entry[1] = 0;
-	/* truncate listing ? */
-	if (!nr) {
-		dprintk("NFS: readdir reply truncated!\n");
-		entry[1] = 1;
-	}
-	goto out;
+	if (nr)
+		goto out;
 err_unmap:
 	kunmap_atomic(kaddr, KM_USER0);
 	return -errno_NFSERR_IO;