On Fri, Aug 29, 2014 at 2:55 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote: > From: "J. Bruce Fields" <bfields@xxxxxxxxxx> > > 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. > > Cc: stable@xxxxxxxxxx > Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> > --- > fs/nfsd/nfs4xdr.c | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > index f9821ce6658a..e94457c33ad6 100644 > --- a/fs/nfsd/nfs4xdr.c > +++ b/fs/nfsd/nfs4xdr.c > @@ -2657,6 +2657,7 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen, > 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; > @@ -2718,7 +2719,14 @@ nfsd4_encode_dirent(void *ccdv, const char *name, int namlen, > 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; > @@ -3321,6 +3329,10 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4 > } > 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; > + Ah... Time to change the Linux client to always set this value to 0. It really is useless in our case. -- Trond Myklebust Linux NFS client maintainer, PrimaryData trond.myklebust@xxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
