- Assert that dm_lock is exclusively held in devfs_rules_apply() and

in devfs_vmkdir() while adding the entry to de_list of the parent.
- Apply devfs rules to newly created directories and symbolic links.

PR:		kern/125034
Submitted by:	Mateusz Guzik (original version)

sys/fs/devfs/devfs_devs.c

@@ -281,8 +281,10 @@ devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dire
 		de->de_dir = dd;
 	} else {
 		de->de_dir = dotdot;
+		sx_assert(&dmp->dm_lock, SX_XLOCKED);
 		TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
 		dotdot->de_links++;
+		devfs_rules_apply(dmp, dd);
 	}
 
 #ifdef MAC

sys/fs/devfs/devfs_rule.c

@@ -139,6 +139,8 @@ devfs_rules_apply(struct devfs_mount *dm, struct devfs_dirent *de)
 {
 	struct devfs_ruleset *ds;
 
+	sx_assert(&dm->dm_lock, SX_XLOCKED);
+
 	if (dm->dm_ruleset == 0)
 		return;
 	sx_slock(&sx_rules);

sys/fs/devfs/devfs_vnops.c

@@ -1589,6 +1589,7 @@ devfs_symlink(struct vop_symlink_args *ap)
 	de_dotdot = TAILQ_NEXT(de_dotdot, de_list);	/* ".." */
 	TAILQ_INSERT_AFTER(&dd->de_dlist, de_dotdot, de, de_list);
 	devfs_dir_ref_de(dmp, dd);
+	devfs_rules_apply(dmp, de);
 
 	return (devfs_allocv(de, ap->a_dvp->v_mount, LK_EXCLUSIVE, ap->a_vpp));
 }