Modify the file handle hash function in the experimental NFS

server so that it will work better for non-UFS file systems.
The new function simply sums the bytes of the fh_fid field
of fhandle_t.

MFC after:	10 days

3 files changed, 17 insertions, 1 deletions

diff --git a/sys/fs/nfs/nfs_var.h b/sys/fs/nfs/nfs_var.h
index d46983f..03b7a0a 100644
--- a/sys/fs/nfs/nfs_var.h
+++ b/sys/fs/nfs/nfs_var.h
@@ -576,6 +576,7 @@ void nfsvno_unlockvfs(mount_t);
 int nfsvno_lockvfs(mount_t);
 int nfsrv_v4rootexport(void *, struct ucred *, NFSPROC_T *);
 int nfsvno_testexp(struct nfsrv_descript *, struct nfsexstuff *);
+int nfsrv_hashfh(fhandle_t *);
 
 /* nfs_commonkrpc.c */
 int newnfs_nmcancelreqs(struct nfsmount *);
diff --git a/sys/fs/nfs/nfsdport.h b/sys/fs/nfs/nfsdport.h
index fdba916..4888866 100644
--- a/sys/fs/nfs/nfsdport.h
+++ b/sys/fs/nfs/nfsdport.h
@@ -73,7 +73,7 @@ struct nfsexstuff {
      bcmp(&(f1)->fh_fid, &(f2)->fh_fid, sizeof(struct fid)) == 0)
 
 #define	NFSLOCKHASH(f) 							\
-	(&nfslockhash[(*((u_int32_t *)((f)->fh_fid.fid_data))) % NFSLOCKHASHSIZE])
+	(&nfslockhash[nfsrv_hashfh(f) % NFSLOCKHASHSIZE])
 
 #define	NFSFPVNODE(f)	((struct vnode *)((f)->f_data))
 #define	NFSFPCRED(f)	((f)->f_cred)
diff --git a/sys/fs/nfsserver/nfs_nfsdport.c b/sys/fs/nfsserver/nfs_nfsdport.c
index 0d35d1d..b49442f 100644
--- a/sys/fs/nfsserver/nfs_nfsdport.c
+++ b/sys/fs/nfsserver/nfs_nfsdport.c
@@ -3087,6 +3087,21 @@ nfsvno_testexp(struct nfsrv_descript *nd, struct nfsexstuff *exp)
 	return (1);
 }
 
+/*
+ * Calculate a hash value for the fid in a file handle.
+ */
+int
+nfsrv_hashfh(fhandle_t *fhp)
+{
+	int hashval = 0, i;
+	uint8_t *cp;
+
+	cp = (uint8_t *)&fhp->fh_fid;
+	for (i = 0; i < sizeof(struct fid); i++)
+		hashval += *cp++;
+	return (hashval);
+}
+
 extern int (*nfsd_call_nfsd)(struct thread *, struct nfssvc_args *);
 
 /*