From 80baab88bb93eeaa133b426d24dfc0775a8cf824 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Sun, 15 Jan 2023 08:45:51 -0800 Subject: iomap/gfs2: Unlock and put folio in page_done handler When an iomap defines a ->page_done() handler in its page_ops, delegate unlocking the folio and putting the folio reference to that handler. This allows to fix a race between journaled data writes and folio writeback in gfs2: before this change, gfs2_iomap_page_done() was called after unlocking the folio, so writeback could start writing back the folio's buffers before they could be marked for writing to the journal. Also, try_to_free_buffers() could free the buffers before gfs2_iomap_page_done() was done adding the buffers to the current current transaction. With this change, gfs2_iomap_page_done() adds the buffers to the current transaction while the folio is still locked, so the problems described above can no longer occur. The only current user of ->page_done() is gfs2, so other filesystems are not affected. To catch out any out-of-tree users, switch from a page to a folio in ->page_done(). Signed-off-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Darrick J. Wong --- fs/iomap/buffered-io.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs/iomap/buffered-io.c') diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index c045689b6af8..a9082078e4ed 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -580,12 +580,12 @@ static void __iomap_put_folio(struct iomap_iter *iter, loff_t pos, size_t ret, { const struct iomap_page_ops *page_ops = iter->iomap.page_ops; - if (folio) + if (page_ops && page_ops->page_done) { + page_ops->page_done(iter->inode, pos, ret, folio); + } else if (folio) { folio_unlock(folio); - if (page_ops && page_ops->page_done) - page_ops->page_done(iter->inode, pos, ret, &folio->page); - if (folio) folio_put(folio); + } } static int iomap_write_begin_inline(const struct iomap_iter *iter, -- cgit v1.2.3