svn commit: r220985 - in head/sys/ufs: ffs ufs

[Konstantin Belousov]

Author: kib
Date: Sun Apr 24 10:47:56 2011
New Revision: 220985
URL: http://svn.freebsd.org/changeset/base/220985

Log:
  VFS sometimes is unable to inactivate a vnode when vnode use count
  goes to zero. E.g., the vnode might be only shared-locked at the time of
  vput() call. Such vnodes are kept in the hash, so they can be found later.
  
  If ffs_valloc() allocated an inode that has its vnode cached in hash, and
  still owing the inactivation, then vget() call from ffs_valloc() clears
  VI_OWEINACT, and then the vnode is reused for the newly allocated inode.
  
  The problem is, the vnode is not reclaimed before it is put to the new
  use. ffs_valloc() recycles vnode vm object, but this is not enough.
  In particular, at least v_vflag should be cleared, and several bits of
  UFS state need to be removed.
  
  It is very inconvenient to call vgone() at this point. Instead, move
  some parts of ufs_reclaim() into helper function ufs_prepare_reclaim(),
  and call the helper from VOP_RECLAIM and ffs_valloc().
  
  Reviewed by:	mckusick
  Tested by:	pho
  MFC after:	3 weeks

Modified:
  head/sys/ufs/ffs/ffs_alloc.c
  head/sys/ufs/ufs/ufs_extern.h
  head/sys/ufs/ufs/ufs_inode.c

Modified: head/sys/ufs/ffs/ffs_alloc.c
==============================================================================
--- head/sys/ufs/ffs/ffs_alloc.c	Sun Apr 24 10:41:13 2011	(r220984)
+++ head/sys/ufs/ffs/ffs_alloc.c	Sun Apr 24 10:47:56 2011	(r220985)
@@ -1012,8 +1012,9 @@ dup_alloc:
 		ip->i_din2->di_birthtime = ts.tv_sec;
 		ip->i_din2->di_birthnsec = ts.tv_nsec;
 	}
+	ufs_prepare_reclaim(*vpp);
 	ip->i_flag = 0;
-	vnode_destroy_vobject(*vpp);
+	(*vpp)->v_vflag = 0;
 	(*vpp)->v_type = VNON;
 	if (fs->fs_magic == FS_UFS2_MAGIC)
 		(*vpp)->v_op = &ffs_vnodeops2;

Modified: head/sys/ufs/ufs/ufs_extern.h
==============================================================================
--- head/sys/ufs/ufs/ufs_extern.h	Sun Apr 24 10:41:13 2011	(r220984)
+++ head/sys/ufs/ufs/ufs_extern.h	Sun Apr 24 10:47:56 2011	(r220985)
@@ -76,6 +76,7 @@ int	 ufs_inactive(struct vop_inactive_ar
 int	 ufs_init(struct vfsconf *);
 void	 ufs_itimes(struct vnode *vp);
 int	 ufs_lookup(struct vop_cachedlookup_args *);
+void	 ufs_prepare_reclaim(struct vnode *vp);
 int	 ufs_readdir(struct vop_readdir_args *);
 int	 ufs_reclaim(struct vop_reclaim_args *);
 void	 ffs_snapgone(struct inode *);

Modified: head/sys/ufs/ufs/ufs_inode.c
==============================================================================
--- head/sys/ufs/ufs/ufs_inode.c	Sun Apr 24 10:41:13 2011	(r220984)
+++ head/sys/ufs/ufs/ufs_inode.c	Sun Apr 24 10:47:56 2011	(r220985)
@@ -172,6 +172,31 @@ out:
 	return (error);
 }
 
+void
+ufs_prepare_reclaim(struct vnode *vp)
+{
+	struct inode *ip;
+#ifdef QUOTA
+	int i;
+#endif
+
+	ip = VTOI(vp);
+
+	vnode_destroy_vobject(vp);
+#ifdef QUOTA
+	for (i = 0; i < MAXQUOTAS; i++) {
+		if (ip->i_dquot[i] != NODQUOT) {
+			dqrele(vp, ip->i_dquot[i]);
+			ip->i_dquot[i] = NODQUOT;
+		}
+	}
+#endif
+#ifdef UFS_DIRHASH
+	if (ip->i_dirhash != NULL)
+		ufsdirhash_free(ip);
+#endif
+}
+
 /*
  * Reclaim an inode so that it can be used for other purposes.
  */
@@ -185,14 +210,9 @@ ufs_reclaim(ap)
 	struct vnode *vp = ap->a_vp;
 	struct inode *ip = VTOI(vp);
 	struct ufsmount *ump = ip->i_ump;
-#ifdef QUOTA
-	int i;
-#endif
 
-	/*
-	 * Destroy the vm object and flush associated pages.
-	 */
-	vnode_destroy_vobject(vp);
+	ufs_prepare_reclaim(vp);
+
 	if (ip->i_flag & IN_LAZYMOD)
 		ip->i_flag |= IN_MODIFIED;
 	UFS_UPDATE(vp, 0);
@@ -200,21 +220,7 @@ ufs_reclaim(ap)
 	 * Remove the inode from its hash chain.
 	 */
 	vfs_hash_remove(vp);
-	/*
-	 * Purge old data structures associated with the inode.
-	 */
-#ifdef QUOTA
-	for (i = 0; i < MAXQUOTAS; i++) {
-		if (ip->i_dquot[i] != NODQUOT) {
-			dqrele(vp, ip->i_dquot[i]);
-			ip->i_dquot[i] = NODQUOT;
-		}
-	}
-#endif
-#ifdef UFS_DIRHASH
-	if (ip->i_dirhash != NULL)
-		ufsdirhash_free(ip);
-#endif
+
 	/*
 	 * Lock the clearing of v_data so ffs_lock() can inspect it
 	 * prior to obtaining the lock.