lkml.org 
[lkml]   [2014]   [Oct]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.16 155/357] nfsd4: fix rd_dircount enforcement
Date
3.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: "J. Bruce Fields" <bfields@redhat.com>

commit aee3776441461c14ba6d8ed9e2149933e65abb6e upstream.

Commit 3b299709091b "nfsd4: enforce rd_dircount" totally misunderstood
rd_dircount; it refers to total non-attribute bytes returned, not number
of directory entries returned.

Bring the code into agreement with RFC 3530 section 14.2.24.

Fixes: 3b299709091b "nfsd4: enforce rd_dircount"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/nfsd/nfs4xdr.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2662,6 +2662,7 @@ nfsd4_encode_dirent(void *ccdv, const ch
struct xdr_stream *xdr = cd->xdr;
int start_offset = xdr->buf->len;
int cookie_offset;
+ u32 name_and_cookie;
int entry_bytes;
__be32 nfserr = nfserr_toosmall;
__be64 wire_offset;
@@ -2723,7 +2724,14 @@ nfsd4_encode_dirent(void *ccdv, const ch
cd->rd_maxcount -= entry_bytes;
if (!cd->rd_dircount)
goto fail;
- cd->rd_dircount--;
+ /*
+ * RFC 3530 14.2.24 describes rd_dircount as only a "hint", so
+ * let's always let through the first entry, at least:
+ */
+ name_and_cookie = 4 * XDR_QUADLEN(namlen) + 8;
+ if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
+ goto fail;
+ cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
cd->cookie_offset = cookie_offset;
skip_entry:
cd->common.err = nfs_ok;
@@ -3333,6 +3341,10 @@ nfsd4_encode_readdir(struct nfsd4_compou
}
maxcount = min_t(int, maxcount-16, bytes_left);

+ /* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */
+ if (!readdir->rd_dircount)
+ readdir->rd_dircount = INT_MAX;
+
readdir->xdr = xdr;
readdir->rd_maxcount = maxcount;
readdir->common.err = 0;



\
 
 \ /
  Last update: 2014-10-04 03:01    [W:0.967 / U:4.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site