Eliminate the overhead of gratuitous repeated reinitialization of cap_rights

- Add macros to allow preinitialization of cap_rights_t.

- Convert most commonly used code paths to use preinitialized cap_rights_t.
  A 3.6% speedup in fstat was measured with this change.

Reported by:	mjg
Reviewed by:	oshogbo
Approved by:	sbruno
MFC after:	1 month

2 files changed, 3 insertions, 6 deletions

diff --git a/sys/fs/fdescfs/fdesc_vnops.c b/sys/fs/fdescfs/fdesc_vnops.c
index 30ce286074b6..7d94ddf17a51 100644
--- a/sys/fs/fdescfs/fdesc_vnops.c
+++ b/sys/fs/fdescfs/fdesc_vnops.c
@@ -286,7 +286,6 @@ fdesc_lookup(struct vop_lookup_args *ap)
 	struct thread *td = cnp->cn_thread;
 	struct file *fp;
 	struct fdesc_get_ino_args arg;
-	cap_rights_t rights;
 	int nlen = cnp->cn_namelen;
 	u_int fd, fd1;
 	int error;
@@ -331,7 +330,7 @@ fdesc_lookup(struct vop_lookup_args *ap)
 	/*
 	 * No rights to check since 'fp' isn't actually used.
 	 */
-	if ((error = fget(td, fd, cap_rights_init(&rights), &fp)) != 0)
+	if ((error = fget(td, fd, &cap_no_rights, &fp)) != 0)
 		goto bad;
 
 	/* Check if we're looking up ourselves. */
@@ -613,7 +612,6 @@ static int
 fdesc_readlink(struct vop_readlink_args *va)
 {
 	struct vnode *vp, *vn;
-	cap_rights_t rights;
 	struct thread *td;
 	struct uio *uio;
 	struct file *fp;
@@ -631,7 +629,7 @@ fdesc_readlink(struct vop_readlink_args *va)
 	VOP_UNLOCK(vn, 0);
 
 	td = curthread;
-	error = fget_cap(td, fd_fd, cap_rights_init(&rights), &fp, NULL);
+	error = fget_cap(td, fd_fd, &cap_no_rights, &fp, NULL);
 	if (error != 0)
 		goto out;
 
diff --git a/sys/fs/fuse/fuse_vfsops.c b/sys/fs/fuse/fuse_vfsops.c
index 700d4450c2e7..0be6185e558e 100644
--- a/sys/fs/fuse/fuse_vfsops.c
+++ b/sys/fs/fuse/fuse_vfsops.c
@@ -222,7 +222,6 @@ fuse_vfsop_mount(struct mount *mp)
 	struct file *fp, *fptmp;
 	char *fspec, *subtype;
 	struct vfsoptlist *opts;
-	cap_rights_t rights;
 
 	subtype = NULL;
 	max_read_set = 0;
@@ -292,7 +291,7 @@ fuse_vfsop_mount(struct mount *mp)
 
 	FS_DEBUG2G("mntopts 0x%jx\n", (uintmax_t)mntopts);
 
-	err = fget(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
+	err = fget(td, fd, &cap_read_rights, &fp);
 	if (err != 0) {
 		FS_DEBUG("invalid or not opened device: data=%p\n", data);
 		goto out;