knfsd: nfsd4: implement secinfo

Implement the secinfo operation.

(Thanks to Usha Ketineni wrote an earlier version of this support.)

Cc: Usha Ketineni <uketinen@us.ibm.com>
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
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>
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index a106e3b..3c62712 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -47,6 +47,7 @@
 #include <linux/nfsd/state.h>
 #include <linux/nfsd/xdr4.h>
 #include <linux/nfs4_acl.h>
+#include <linux/sunrpc/gss_api.h>
 
 #define NFSDDBG_FACILITY		NFSDDBG_PROC
 
@@ -610,6 +611,30 @@
 }
 
 static __be32
+nfsd4_secinfo(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
+	      struct nfsd4_secinfo *secinfo)
+{
+	struct svc_fh resfh;
+	struct svc_export *exp;
+	struct dentry *dentry;
+	__be32 err;
+
+	fh_init(&resfh, NFS4_FHSIZE);
+	err = nfsd_lookup_dentry(rqstp, &cstate->current_fh,
+				    secinfo->si_name, secinfo->si_namelen,
+				    &exp, &dentry);
+	if (err)
+		return err;
+	if (dentry->d_inode == NULL) {
+		exp_put(exp);
+		err = nfserr_noent;
+	} else
+		secinfo->si_exp = exp;
+	dput(dentry);
+	return err;
+}
+
+static __be32
 nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	      struct nfsd4_setattr *setattr)
 {
@@ -1008,6 +1033,9 @@
 	[OP_SAVEFH] = {
 		.op_func = (nfsd4op_func)nfsd4_savefh,
 	},
+	[OP_SECINFO] = {
+		.op_func = (nfsd4op_func)nfsd4_secinfo,
+	},
 	[OP_SETATTR] = {
 		.op_func = (nfsd4op_func)nfsd4_setattr,
 	},