1 files changed, 31 insertions, 5 deletions

diff --git a/fs/nfsd/lockd.c b/fs/nfsd/lockd.c
index 3f5b3d7b62b7..c774ce9aa296 100644
--- a/fs/nfsd/lockd.c
+++ b/fs/nfsd/lockd.c
@@ -25,26 +25,52 @@
  * Note: we hold the dentry use count while the file is open.
  */
 static __be32
-nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp)
+nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp,
+		int mode)
 {
 	__be32		nfserr;
+	int		access;
 	struct svc_fh	fh;
 
 	/* must initialize before using! but maxsize doesn't matter */
 	fh_init(&fh,0);
 	fh.fh_handle.fh_size = f->size;
-	memcpy((char*)&fh.fh_handle.fh_base, f->data, f->size);
+	memcpy(&fh.fh_handle.fh_raw, f->data, f->size);
 	fh.fh_export = NULL;
 
-	nfserr = nfsd_open(rqstp, &fh, S_IFREG, NFSD_MAY_LOCK, filp);
+	/*
+	 * Allow BYPASS_GSS as some client implementations use AUTH_SYS
+	 * for NLM even when GSS is used for NFS.
+	 * Allow OWNER_OVERRIDE as permission might have been changed
+	 * after the file was opened.
+	 * Pass MAY_NLM so that authentication can be completely bypassed
+	 * if NFSEXP_NOAUTHNLM is set.  Some older clients use AUTH_NULL
+	 * for NLM requests.
+	 */
+	access = (mode == O_WRONLY) ? NFSD_MAY_WRITE : NFSD_MAY_READ;
+	access |= NFSD_MAY_NLM | NFSD_MAY_OWNER_OVERRIDE | NFSD_MAY_BYPASS_GSS;
+	nfserr = nfsd_open(rqstp, &fh, S_IFREG, access, filp);
 	fh_put(&fh);
- 	/* We return nlm error codes as nlm doesn't know
+	/* We return nlm error codes as nlm doesn't know
 	 * about nfsd, but nfsd does know about nlm..
 	 */
 	switch (nfserr) {
 	case nfs_ok:
 		return 0;
-	case nfserr_dropit:
+	case nfserr_jukebox:
+		/* this error can indicate a presence of a conflicting
+		 * delegation to an NLM lock request. Options are:
+		 * (1) For now, drop this request and make the client
+		 * retry. When delegation is returned, client's lock retry
+		 * will complete.
+		 * (2) NLM4_DENIED as per "spec" signals to the client
+		 * that the lock is unavailable now but client can retry.
+		 * Linux client implementation does not. It treats
+		 * NLM4_DENIED same as NLM4_FAILED and errors the request.
+		 * (3) For the future, treat this as blocked lock and try
+		 * to callback when the delegation is returned but might
+		 * not have a proper lock request to block on.
+		 */
 		return nlm_drop_reply;
 	case nfserr_stale:
 		return nlm_stale_fh;