On Tue, Jan 7, 2020 at 4:18 PM David Sterba <dsterba@xxxxxxx> wrote:
>
> On Mon, Jan 06, 2020 at 02:29:01PM -0500, Josef Bacik wrote:
> > On 1/6/20 12:22 PM, David Sterba wrote:
> > > On Mon, Dec 30, 2019 at 04:31:15PM -0500, Josef Bacik wrote:
> > >> @@ -60,6 +60,11 @@ struct btrfs_inode {
> > >> */
> > >> struct extent_io_tree io_failure_tree;
> > >>
> > >> + /* keeps track of where we have extent items mapped in order to make
> > >> + * sure our i_size adjustments are accurate.
> > >> + */
> > >> + struct extent_io_tree file_extent_tree;
> > >
> > > This is not exactly lightweight and cut to the minimum needed, the size
> > > is 40 bytes and contains struct members that are unused. At least the
> > > file extents tree seems to be in use unlike that io_failure_tree wasting
> > > the bytes almost 100% of time.
> > >
> >
> > I'm not in love with it either, but I don't want to invent some lighter weight
> > range thingy that I'm going to end up messing up in other ways.
>
> Yeah, the extent_io_tree is now being used for generic range tree, some
> cleanups could remove the members that were added for the first specific
> use (like the dirty_bytes, or track_updates). For correctness of NOHOLES
> the inode size increase shouldn't be a blocker but needs to be addressed
> later.
Hum?
This isn't about the NO_HOLES case, it's about unordered i_size update
which can often lead to missing extent items for a file - when using
NO_HOLES fsck simply doesn't report any issue, but when not using it,
it does report about missing extents.
>
> > Don't take this series yet, there's still something fishy going on that I have
> > to figure out. Thanks,
>
> Ok.
--
Filipe David Manana,
“Whether you think you can, or you think you can't — you're right.”
