svn commit: r212305 - head/sys/fs/tmpfs

[Ivan Voras]

Author: ivoras
Date: Tue Sep  7 22:40:45 2010
New Revision: 212305
URL: http://svn.freebsd.org/changeset/base/212305

Log:
  Avoid "Entry can disappear before we lock fdvp" panic.
  
  PR:		150143
  Submitted by:	Gleb Kurtsou <gk at FreeBSD.org>
  Pretty sure it won't blow up: mckusick
  MFC after:	2 weeks

Modified:
  head/sys/fs/tmpfs/tmpfs_vnops.c

Modified: head/sys/fs/tmpfs/tmpfs_vnops.c
==============================================================================
--- head/sys/fs/tmpfs/tmpfs_vnops.c	Tue Sep  7 21:28:45 2010	(r212304)
+++ head/sys/fs/tmpfs/tmpfs_vnops.c	Tue Sep  7 22:40:45 2010	(r212305)
@@ -981,10 +981,14 @@ tmpfs_rename(struct vop_rename_args *v)
 	fnode = VP_TO_TMPFS_NODE(fvp);
 	de = tmpfs_dir_lookup(fdnode, fnode, fcnp);
 
-	/* Avoid manipulating '.' and '..' entries. */
+	/* Entry can disappear before we lock fdvp,
+	 * also avoid manipulating '.' and '..' entries. */
 	if (de == NULL) {
-		MPASS(fvp->v_type == VDIR);
-		error = EINVAL;
+		if ((fcnp->cn_flags & ISDOTDOT) != 0 ||
+		    (fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.'))
+			error = EINVAL;
+		else
+			error = ENOENT;
 		goto out_locked;
 	}
 	MPASS(de->td_node == fnode);