Subject: softdep improvement
To: None <tech-kern@netbsd.org>
From: Matthias Drochner <M.Drochner@fz-juelich.de>
List: tech-kern
Date: 06/28/2006 19:40:22
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Hi -
here is a patch to softdep code which appears to have a good effect
on recovery after crashes for me. I've been running it on my laptop
for a couple of days, and haven't seen any bad effect, whether the
box was running or crashing.
How about pulling this in?
Here is the original changelog, with a paragraph about background fsck
left out:

> revision 1.185 date: 2005/09/29 21:50:26;  author: truckman;  state:
> Exp;  lines: +2 -0
> After a rmdir()ed directory has been truncated,
> force an update of the directory's inode after queuing the dirrem that
> will decrement the parent directory's link count.  This will force the
> update of the parent directory's actual link to actually be scheduled.
>  Without this change the parent directory's actual link count would
> not be updated until ufs_inactive() cleared the inode of the newly
> removed directory, which might be deferred indefinitely.
> ufs_inactive() will not be called as long as any process holds a
> reference to the removed directory, and ufs_inactive() will not clear
> the inode if the link count is non-zero, which could be the result of
> an earlier system crash.
> [...]
> This change has the fortunate side effect of more quickly cleaning up
> the large number dirrem structures that linger for an extended time
> after the removal of a large directory tree.  It also fixes a
> potential problem with the shutdown of the syncer thread timing out if
> the system is rebooted immediately after removing a large directory
> tree. 

best regards
Matthias



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Index: ffs_softdep.c
===================================================================
RCS file: /cvsroot/src/sys/ufs/ffs/ffs_softdep.c,v
retrieving revision 1.75
diff -u -p -r1.75 ffs_softdep.c
--- ffs_softdep.c	12 Jun 2006 16:37:00 -0000	1.75
+++ ffs_softdep.c	28 Jun 2006 16:46:29 -0000
@@ -3346,6 +3346,8 @@ handle_workitem_remove(dirrem)
 	}
 	WORKLIST_INSERT(&inodedep->id_inowait, &dirrem->dm_list);
 	FREE_LOCK(&lk);
+	ip->i_flag |= IN_CHANGE;
+	ffs_update(vp, NULL, NULL, 0);
 	vput(vp);
 }
 

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