svn commit: r184408 - head/sys/ufs/ufs

[Konstantin Belousov]

Author: kib
Date: Tue Oct 28 12:00:28 2008
New Revision: 184408
URL: http://svn.freebsd.org/changeset/base/184408

Log:
  Provide an explanation for getinoquota() call in the ufs_access vop.
  
  MFC after:	3 days

Modified:
  head/sys/ufs/ufs/ufs_vnops.c

Modified: head/sys/ufs/ufs/ufs_vnops.c
==============================================================================
--- head/sys/ufs/ufs/ufs_vnops.c	Tue Oct 28 11:33:06 2008	(r184407)
+++ head/sys/ufs/ufs/ufs_vnops.c	Tue Oct 28 12:00:28 2008	(r184408)
@@ -330,7 +330,18 @@ ufs_access(ap)
 			if (vp->v_mount->mnt_flag & MNT_RDONLY)
 				return (EROFS);
 #ifdef QUOTA
+			/*
+			 * Inode is accounted in the quotas only if struct
+			 * dquot is attached to it. VOP_ACCESS() is called
+			 * from vn_open_cred() and provides a convenient
+			 * point to call getinoquota().
+			 */
 			if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
+
+				/*
+				 * Upgrade vnode lock, since getinoquota()
+				 * requires exclusive lock to modify inode.
+				 */
 				relocked = 1;
 				vhold(vp);
 				vn_lock(vp, LK_UPGRADE | LK_RETRY);