On Tue, Dec 13, 2022 at 08:48:33PM +0100, Andreas Gruenbacher wrote: > Hi Darrick, > > I'd like to get the following iomap change into this merge window. This > only affects gfs2, so I can push it as part of the gfs2 updates if you > don't mind, provided that I'll get your Reviewed-by confirmation. > Otherwise, if you'd prefer to pass this through the xfs tree, could you > please take it? I don't mind you pushing changes to ->page_done through the gfs2 tree, but don't you need to move the other callsite at the bottom of iomap_write_begin? --D > Thanks, > Andreas > > -- > > Move the ->page_done() call in iomap_write_end() under the folio lock. > This closes a race between journaled data writes and the shrinker in > gfs2. What's happening is that gfs2_iomap_page_done() is called after > the page has been unlocked, so try_to_free_buffers() can come in and > free the buffers while gfs2_iomap_page_done() is trying to add them to > the current transaction. The folio lock prevents that from happening. > > The only user of ->page_done() is gfs2, so other filesystems are not > affected. > > Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx> > --- > fs/iomap/buffered-io.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index 91ee0b308e13..476c9ed1b333 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -714,12 +714,12 @@ static size_t iomap_write_end(struct iomap_iter *iter, loff_t pos, size_t len, > i_size_write(iter->inode, pos + ret); > iter->iomap.flags |= IOMAP_F_SIZE_CHANGED; > } > + if (page_ops && page_ops->page_done) > + page_ops->page_done(iter->inode, pos, ret, &folio->page); > folio_unlock(folio); > > if (old_size < pos) > pagecache_isize_extended(iter->inode, old_size, pos); > - if (page_ops && page_ops->page_done) > - page_ops->page_done(iter->inode, pos, ret, &folio->page); > folio_put(folio); > > if (ret < len) > -- > 2.38.1 >
