Hello, we're seeing a race between journaled data writes and the shrinker on 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 transaction. Not good. This is a proposal to change iomap_page_ops so that page_prepare() prepares the write and grabs the locked page, and page_done() unlocks and puts that page again. While at it, this also converts the hooks from pages to folios. To move the pagecache_isize_extended() call in iomap_write_end() out of the way, a new folio_may_straddle_isize() helper is introduced that takes a locked folio. That is then used when the inode size is updated, before the folio is unlocked. I've also converted the other applicable folio_may_straddle_isize() users, namely generic_write_end(), ext4_write_end(), and ext4_journalled_write_end(). Any thoughts? Thanks, Andreas Andreas Gruenbacher (3): fs: Add folio_may_straddle_isize helper iomap: Turn iomap_page_ops into iomap_folio_ops gfs2: Fix race between shrinker and gfs2_iomap_folio_done fs/buffer.c | 5 ++--- fs/ext4/inode.c | 13 +++++------ fs/gfs2/bmap.c | 39 +++++++++++++++++++++++--------- fs/iomap/buffered-io.c | 51 +++++++++++++++++++++--------------------- include/linux/iomap.h | 24 ++++++++++---------- include/linux/mm.h | 2 ++ mm/truncate.c | 34 ++++++++++++++++++++++++++++ 7 files changed, 110 insertions(+), 58 deletions(-) -- 2.38.1
