Re: [PATCH 1/9] Btrfs: introduce sub transaction stuff

[Chris Mason <chris.mason@oracle.com>]

Excerpts from liubo's message of 2011-05-25 06:21:04 -0400:
> On 05/24/2011 11:56 PM, liubo wrote:
> >> > The problems I hit:
> >> > 
> >> > When an inode is dropped from cache (just via iput) and then read in
> >> > again, the BTRFS_I(inode)->logged_trans goes back to zero.  When this
> >> > happens the logging code assumes the inode isn't in the log and hits
> >> > -EEXIST if it finds inode items.
> >> > 
> > 
> > ok, I just find where the problem addresses.  This is because I've put
> > a check between logged_trans and transaction_id, which is inclined to
> > filter those that are first logged, and I'm sorry for not taking the
> > 'iput' stuff into consideration.  And it's easy to fix this, as we
> > can just kick this check off and put another check while searching
> > 'BTRFS_INODE_ITEM_KEY', since if we cannot find a inode item in a tree,
> > it proves that this inode is definitely not in the tree.
> > 
> > So I'd like to make some changes like this patch(_UNTEST_):
> 
> I've thought of this problem more and came up with a _better and more efficient_ patch.
> It will always get BTRFS_I(inode)->logged_trans correct value.

Thanks, this makes sense.

> 
> But I'm still trying to test it somehow... :P

http://oss.oracle.com/~mason/synctest/synctest.c

I used synctest -F -f -u -n 100 -t 32 .

-chris