Messages in this thread | | | Date | Tue, 18 Dec 2007 20:14:36 -0500 | From | Erez Zadok <> | Subject | Re: [PATCH 3/4] unionfs: restructure unionfs_setattr |
| |
In message <Pine.LNX.4.64.0712190030390.5639@blonde.wat.veritas.com>, Hugh Dickins writes: > On Tue, 18 Dec 2007, Erez Zadok wrote: > > In message <Pine.LNX.4.64.0712182213300.28390@blonde.wat.veritas.com>, Hugh Dickins writes: > > > In order to fix unionfs truncation, we need to move the lower notify_change > > > out of the loop in unionfs_setattr. But when I came to do that, I couldn't > > [...] > > > > Hugh, I want to understand how patches 3/4 and 4/4 are related. In patch 3 > > you say "in order to fix truncation" but you mention a truncation problem > > only in patch 4; is there a patch ordering problem, or they're both related > > to the same issue (with 3/4 being a code cleanup, and 4/4 actually fixing > > the problem)? > > I needed to move that notify_change out of the loop, to fix the truncation > problem, but had great difficulty understanding the loop. So, just as you > say, made the code cleanup first in 3/4, then fixed the problem in 4/4. > > But that cleanup does need your review and testing.
A quick look at your setattr patches seems very promising. And I've further realized more cleanup is possible: because we call revalidate_chain at the opening to ->setattr, we're guaranteed to have a valid lower dentry, so for example we can remove the else case for "if (lower_dentry)".
I'll be testing this and your other patches, plus look into the locking issues you brought up.
Thanks, Erez.
| |