svn commit: r197041 - in stable/8/sys: . amd64/include/xen cddl/contrib/opensolaris contrib/dev/acpica contrib/pf dev/xen/xenpci kern

[Konstantin Belousov]

Author: kib
Date: Wed Sep  9 13:28:18 2009
New Revision: 197041
URL: http://svn.freebsd.org/changeset/base/197041

Log:
  MFC r196887:
  In fhopen, vfs_ref() the mount point while vnode is unlocked, to prevent
  vn_start_write(NULL, &mp) from operating on potentially freed or reused
  struct mount *.
  
  Remove unmatched vfs_rel() in cleanup.
  
  Approved by:	re (kensmith)

Modified:
  stable/8/sys/   (props changed)
  stable/8/sys/amd64/include/xen/   (props changed)
  stable/8/sys/cddl/contrib/opensolaris/   (props changed)
  stable/8/sys/contrib/dev/acpica/   (props changed)
  stable/8/sys/contrib/pf/   (props changed)
  stable/8/sys/dev/xen/xenpci/   (props changed)
  stable/8/sys/kern/   (props changed)
  stable/8/sys/kern/vfs_syscalls.c

Modified: stable/8/sys/kern/vfs_syscalls.c
==============================================================================
--- stable/8/sys/kern/vfs_syscalls.c	Wed Sep  9 13:23:26 2009	(r197040)
+++ stable/8/sys/kern/vfs_syscalls.c	Wed Sep  9 13:28:18 2009	(r197041)
@@ -4439,12 +4439,15 @@ fhopen(td, uap)
 			goto bad;
 	}
 	if (fmode & O_TRUNC) {
+		vfs_ref(mp);
 		VOP_UNLOCK(vp, 0);				/* XXX */
 		if ((error = vn_start_write(NULL, &mp, V_WAIT | PCATCH)) != 0) {
 			vrele(vp);
+			vfs_rel(mp);
 			goto out;
 		}
 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);	/* XXX */
+		vfs_rel(mp);
 #ifdef MAC
 		/*
 		 * We don't yet have fp->f_cred, so use td->td_ucred, which
@@ -4516,7 +4519,6 @@ fhopen(td, uap)
 
 	VOP_UNLOCK(vp, 0);
 	fdrop(fp, td);
-	vfs_rel(mp);
 	VFS_UNLOCK_GIANT(vfslocked);
 	td->td_retval[0] = indx;
 	return (0);