knfsd: nfsd: use ip-address-based domain in secinfo case

With this patch, we fall back on using the gss/pseudoflavor only if we fail to
find a matching auth_unix export that has a secinfo list.

As long as sec= options aren't used, there's still no change in behavior here
(except possibly for some additional auth_unix cache lookups, whose results
will be ignored).

The sec= option, however, is not actually enforced yet; later patches will add
the necessary checks.

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 67 insertions, 9 deletions

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index ac225a79376..4537a8f5cb9 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1229,6 +1229,10 @@ exp_find(struct auth_domain *clp, int fsid_type, u32 *fsidv,
 }
 
 /*
+ * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
+ * auth_unix client) if it's available and has secinfo information;
+ * otherwise, will try to use rq_gssclient.
+ *
  * Called from functions that handle requests; functions that do work on
  * behalf of mountd are passed a single client name to use, and should
  * use exp_get_by_name() or exp_find().
@@ -1237,29 +1241,83 @@ struct svc_export *
 rqst_exp_get_by_name(struct svc_rqst *rqstp, struct vfsmount *mnt,
                 struct dentry *dentry)
 {
-        struct auth_domain *clp;
+        struct svc_export *gssexp, *exp = NULL;
+
+        if (rqstp->rq_client == NULL)
+                goto gss;
 
-        clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
-        return exp_get_by_name(clp, mnt, dentry, &rqstp->rq_chandle);
+        /* First try the auth_unix client: */
+        exp = exp_get_by_name(rqstp->rq_client, mnt, dentry,
+                                                &rqstp->rq_chandle);
+        if (PTR_ERR(exp) == -ENOENT)
+                goto gss;
+        if (IS_ERR(exp))
+                return exp;
+        /* If it has secinfo, assume there are no gss/... clients */
+        if (exp->ex_nflavors > 0)
+                return exp;
+gss:
+        /* Otherwise, try falling back on gss client */
+        if (rqstp->rq_gssclient == NULL)
+                return exp;
+        gssexp = exp_get_by_name(rqstp->rq_gssclient, mnt, dentry,
+                                                &rqstp->rq_chandle);
+        if (PTR_ERR(gssexp) == -ENOENT)
+                return exp;
+        if (exp && !IS_ERR(exp))
+                exp_put(exp);
+        return gssexp;
 }
 
 struct svc_export *
 rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
 {
-        struct auth_domain *clp;
+        struct svc_export *gssexp, *exp = NULL;
+
+        if (rqstp->rq_client == NULL)
+                goto gss;
 
-        clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
-        return exp_find(clp, fsid_type, fsidv, &rqstp->rq_chandle);
+        /* First try the auth_unix client: */
+        exp = exp_find(rqstp->rq_client, fsid_type, fsidv, &rqstp->rq_chandle);
+        if (PTR_ERR(exp) == -ENOENT)
+                goto gss;
+        if (IS_ERR(exp))
+                return exp;
+        /* If it has secinfo, assume there are no gss/... clients */
+        if (exp->ex_nflavors > 0)
+                return exp;
+gss:
+        /* Otherwise, try falling back on gss client */
+        if (rqstp->rq_gssclient == NULL)
+                return exp;
+        gssexp = exp_find(rqstp->rq_gssclient, fsid_type, fsidv,
+                                                &rqstp->rq_chandle);
+        if (PTR_ERR(gssexp) == -ENOENT)
+                return exp;
+        if (exp && !IS_ERR(exp))
+                exp_put(exp);
+        return gssexp;
 }
 
 struct svc_export *
 rqst_exp_parent(struct svc_rqst *rqstp, struct vfsmount *mnt,
                 struct dentry *dentry)
 {
-        struct auth_domain *clp;
+        struct svc_export *exp;
 
-        clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
-        return exp_parent(rqstp->rq_client, mnt, dentry, &rqstp->rq_chandle);
+        dget(dentry);
+        exp = rqst_exp_get_by_name(rqstp, mnt, dentry);
+
+        while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(dentry)) {
+                struct dentry *parent;
+
+                parent = dget_parent(dentry);
+                dput(dentry);
+                dentry = parent;
+                exp = rqst_exp_get_by_name(rqstp, mnt, dentry);
+        }
+        dput(dentry);
+        return exp;
 }
 
 /*