On Thu, 2003-04-17 at 20:43, Steven Dake wrote: > Folks, > > I was analyzing the VFS locking patch and I wanted to know if someone > could explain the purpose of a change in the reiserfs for me: > > The change is: > Index: linus.21/fs/reiserfs/super.c > --- linus.21/fs/reiserfs/super.c Fri, 11 Jan 2002 10:14:59 -0500 root > (linux/41_super.c 1.2.2.1.2.1.1.1 644) > +++ linus.21(w)/fs/reiserfs/super.c Mon, 28 Jan 2002 13:50:56 -0500 root > (linux/41_super.c 1.2.2.1.2.1.1.1 644) > @@ -66,7 +66,7 @@ > reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); > journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB (s)); > reiserfs_block_writes(&th) ; > - journal_end(&th, s, 1) ; > + journal_end_sync(&th, s, 1) ; > } > s->s_dirt = dirty; > unlock_kernel() ; > > I tried LVM with and without this change even under heavy load and LVM > can still create mountable snapshots of a reiser filesystem without the > change. Why is it there? journal_end will do an asynchronous commit, which means it won't wait for the journal to actually finish writing to disk. journal_end_sync will wait until the commit is fully on disk. In most cases, the reiserfs_block_writes call is sufficient and the journal_end_sync change isn't needed, but there are a few corner cases depending on the number of log writers where journal_end_sync is required. -chris _______________________________________________ linux-lvm mailing list linux-lvm@sistina.com http://lists.sistina.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
