On Thu 01-08-19 20:12:11, Thomas Gleixner wrote: > On Thu, 1 Aug 2019, Jan Kara wrote: > > On Thu 01-08-19 03:01:32, Thomas Gleixner wrote: > > > As almost all functions which use this lock have a journal head pointer > > > readily available, it makes more sense to remove the lock helper inlines > > > and write out spin_*lock() at all call sites. > > > > > > > Just a heads up that I didn't miss this patch. Just it has some bugs and I > > figured that rather than explaining to you subtleties of jh lifetime it is > > easier to fix up the problems myself since you're probably not keen on > > becoming jbd2 developer ;)... which was more complex than I thought so I'm > > not completely done yet. Hopefuly tomorrow. > > I'm curious where I was too naive :) Well, the most obvious where places where the result ended up being like jbd2_journal_put_journal_head(jh); spin_unlock(&jh->state_lock); That's possible use-after-free. But there were also other more subtle places where jbd2_journal_put_journal_head() was not directly visible as it was hidden inside journal list handling functions such as __jbd2_journal_refile_buffer() or so. And these needed some more work. Anyway, I'm now done fixing up the patch, doing some xfstests runs to verify things didn't break in any obvious way... Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
