Messages in this thread | | | Date | Wed, 25 Apr 2012 21:53:43 +0200 | From | Jan Kara <> | Subject | Re: [PATCH 5/5] vfs: change nondirectory i_mutex ordering to fix quota deadlock |
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On Wed 25-04-12 11:28:58, J. Bruce Fields wrote: > On Wed, Apr 25, 2012 at 11:22:09AM -0400, bfields@fieldses.org wrote: > > diff --git a/fs/inode.c b/fs/inode.c > > index 487c924..13d23b6 100644 > > --- a/fs/inode.c > > +++ b/fs/inode.c > > @@ -961,6 +961,17 @@ void unlock_new_inode(struct inode *inode) > > } > > EXPORT_SYMBOL(unlock_new_inode); > > > > +/* > > + * We order !IS_NOQUOTA files before ISNOQUOTA files, and by pointer > > + * within each category. > > + */ > > +static bool nondir_mutex_ordered(struct inode *inode1, struct inode *inode2) > > +{ > > + if (IS_NOQUOTA(inode1) == IS_NOQUOTA(inode2)) > > + return inode1 < inode2; > > + return IS_NOQUOTA(inode2); > > +} > > This seems kind of awful. Is it what you were thinking of originally, > Al, and could we live with it? Yeah, it's pretty ugly and also racy. I'm just now testing patches that would get rid of I_MUTEX_QUOTA usage for filesystems (except GFS2) and quota code. GFS2 could be certainly dealt with as well (at least by introducing a new GFS2 internal lock) so this ugly code can go away.
Honza
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