On Mon, Aug 04, 2014 at 05:46:47PM -0400, J. Bruce Fields wrote:
> On Mon, Aug 04, 2014 at 11:24:11AM -0400, bfields wrote:
> > +static int
> > +nfsd3_is_readdirplus_supported(struct svc_rqst *rqstp, struct svc_fh *fhp)
> > +{
> > + struct svc_export *exp;
> > + int supported = 1; /* fall back to readdirplus supported in case of errors.*/
> > + int err;
> > +
> > + err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_READ);
> > + if (err) {
> > + goto out;
> > + }
>
> Actually, this isn't right: errors from fh_verify should be returned to
> the client or weird things could happen (e.g. what should have been a
> transient DELAY error could result in the client turning off
> readdirplus).
Apologies, I misread: as the comment above notes, it falls back on
allowing readdirplus when this fails, so I don't think there's a real
bug here.
> And MAY_READ is more than nfsd_readdir actually asks for,
> I think, probably should just be MAY_NOP here.
>
> I'll fix that up.--b.
But it's probably still better to return the fh_verify error on failure,
as follows.
--b.
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 72ffd7cce3c3..30a739d896ff 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1145,6 +1145,7 @@ static struct flags {
{ NFSEXP_ALLSQUASH, {"all_squash", ""}},
{ NFSEXP_ASYNC, {"async", "sync"}},
{ NFSEXP_GATHERED_WRITES, {"wdelay", "no_wdelay"}},
+ { NFSEXP_NOREADDIRPLUS, {"nordirplus", ""}},
{ NFSEXP_NOHIDE, {"nohide", ""}},
{ NFSEXP_CROSSMOUNT, {"crossmnt", ""}},
{ NFSEXP_NOSUBTREECHECK, {"no_subtree_check", ""}},
diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c
index fa2525b2e9d7..247b06fb400d 100644
--- a/fs/nfsd/nfs3proc.c
+++ b/fs/nfsd/nfs3proc.c
@@ -471,6 +471,14 @@ nfsd3_proc_readdirplus(struct svc_rqst *rqstp, struct nfsd3_readdirargs *argp,
resp->buflen = resp->count;
resp->rqstp = rqstp;
offset = argp->cookie;
+
+ nfserr = fh_verify(rqstp, &resp->fh, S_IFDIR, NFSD_MAY_NOP);
+ if (nfserr)
+ RETURN_STATUS(nfserr);
+
+ if (resp->fh.fh_export->ex_flags & NFSEXP_NOREADDIRPLUS)
+ RETURN_STATUS(nfserr_notsupp);
+
nfserr = nfsd_readdir(rqstp, &resp->fh,
&offset,
&resp->common,
diff --git a/include/uapi/linux/nfsd/export.h b/include/uapi/linux/nfsd/export.h
index cf47c313794e..584b6ef3a5e8 100644
--- a/include/uapi/linux/nfsd/export.h
+++ b/include/uapi/linux/nfsd/export.h
@@ -28,7 +28,8 @@
#define NFSEXP_ALLSQUASH 0x0008
#define NFSEXP_ASYNC 0x0010
#define NFSEXP_GATHERED_WRITES 0x0020
-/* 40 80 100 currently unused */
+#define NFSEXP_NOREADDIRPLUS 0x0040
+/* 80 100 currently unused */
#define NFSEXP_NOHIDE 0x0200
#define NFSEXP_NOSUBTREECHECK 0x0400
#define NFSEXP_NOAUTHNLM 0x0800 /* Don't authenticate NLM requests - just trust */
@@ -47,7 +48,7 @@
*/
#define NFSEXP_V4ROOT 0x10000
/* All flags that we claim to support. (Note we don't support NOACL.) */
-#define NFSEXP_ALLFLAGS 0x17E3F
+#define NFSEXP_ALLFLAGS 0x1FE7F
/* The flags that may vary depending on security flavor: */
#define NFSEXP_SECINFO_FLAGS (NFSEXP_READONLY | NFSEXP_ROOTSQUASH \
--
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