In devfs_allocv(), rather than assigning 'td = curthread', assert that

the caller passes in a td that is curthread, and consistently pass 'td'
into vget().  Remove some bogus logic that passed in td or curthread
conditional on td being non-NULL, which seems redundant in the face of
the earlier assignment of td to curthread if td is NULL.

In devfs_symlink(), cache the passed thread in 'td' so we don't have
to keep retrieving it from the 'ap' structure, and assert that td is
curthread (since we dereference it to get thread-local td_ucred).  Use
'td' in preference to curthread for later lockmgr calls, since they are
equal.

1 files changed, 9 insertions, 7 deletions

diff --git a/sys/fs/devfs/devfs_vnops.c b/sys/fs/devfs/devfs_vnops.c
index 2d7468a..88cff6a 100644
--- a/sys/fs/devfs/devfs_vnops.c
+++ b/sys/fs/devfs/devfs_vnops.c
@@ -125,12 +125,11 @@ devfs_allocv(struct devfs_dirent *de, struct mount *mp, struct vnode **vpp, stru
 	struct vnode *vp;
 	struct cdev *dev;
 
-	if (td == NULL)
-		td = curthread; /* XXX */
+	KASSERT(td == curthread, ("devfs_allocv: td != curthread"));
 loop:
 	vp = de->de_vnode;
 	if (vp != NULL) {
-		if (vget(vp, LK_EXCLUSIVE, td ? td : curthread))
+		if (vget(vp, LK_EXCLUSIVE, td))
 			goto loop;
 		*vpp = vp;
 		return (0);
@@ -849,8 +848,11 @@ devfs_symlink(ap)
 	struct devfs_dirent *dd;
 	struct devfs_dirent *de;
 	struct devfs_mount *dmp;
+	struct thread *td;
 
-	error = suser(ap->a_cnp->cn_thread);
+	td = ap->a_cnp->cn_thread;
+	KASSERT(td == curthread, ("devfs_symlink: td != curthread"));
+	error = suser(td);
 	if (error)
 		return(error);
 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
@@ -864,13 +866,13 @@ devfs_symlink(ap)
 	i = strlen(ap->a_target) + 1;
 	MALLOC(de->de_symlink, char *, i, M_DEVFS, M_WAITOK);
 	bcopy(ap->a_target, de->de_symlink, i);
-	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curthread);
+	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, td);
 #ifdef MAC
 	mac_create_devfs_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de);
 #endif
 	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
-	devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp, 0);
-	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
+	devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp, td);
+	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, td);
 	return (0);
 }