Re: [PATCH 05/11] iomap: zero newly allocated mapped blocks
From: Dave Chinner
Date: Mon Oct 07 2019 - 18:08:42 EST
On Tue, Oct 08, 2019 at 08:46:32AM +1100, Dave Chinner wrote:
> On Sun, Oct 06, 2019 at 05:46:02PM +0200, Christoph Hellwig wrote:
> > File systems like gfs2 don't support delayed allocations or unwritten
> > extents and thus allocate normal mapped blocks to fill holes. To
> > cover the case of such file systems allocating new blocks to fill holes
> > also zero out mapped blocks with the new flag.
> >
> > Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> > Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > ---
> > fs/iomap/buffered-io.c | 12 ++++++++++--
> > 1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> > index 23cc308f971d..4132c0cccb0a 100644
> > --- a/fs/iomap/buffered-io.c
> > +++ b/fs/iomap/buffered-io.c
> > @@ -207,6 +207,14 @@ iomap_read_inline_data(struct inode *inode, struct page *page,
> > SetPageUptodate(page);
> > }
> >
> > +static inline bool iomap_block_needs_zeroing(struct inode *inode,
> > + struct iomap *iomap, loff_t pos)
> > +{
> > + return iomap->type != IOMAP_MAPPED ||
> > + (iomap->flags & IOMAP_F_NEW) ||
> > + pos >= i_size_read(inode);
>
> This is a change of logic - why is the IOMAP_F_NEW check added here
> and what bug does it fix?
Sorry, brain-fart here - that's what this patch is adding, it's not
a pure factoring patch.... :/
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx