Merge tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache

Pull page cache updates from Matthew Wilcox:

 - Appoint myself page cache maintainer

 - Fix how scsicam uses the page cache

 - Use the memalloc_nofs_save() API to replace AOP_FLAG_NOFS

 - Remove the AOP flags entirely

 - Remove pagecache_write_begin() and pagecache_write_end()

 - Documentation updates

 - Convert several address_space operations to use folios:
     - is_dirty_writeback
     - readpage becomes read_folio
     - releasepage becomes release_folio
     - freepage becomes free_folio

 - Change filler_t to require a struct file pointer be the first
   argument like ->read_folio

* tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache: (107 commits)
  nilfs2: Fix some kernel-doc comments
  Appoint myself page cache maintainer
  fs: Remove aops->freepage
  secretmem: Convert to free_folio
  nfs: Convert to free_folio
  orangefs: Convert to free_folio
  fs: Add free_folio address space operation
  fs: Convert drop_buffers() to use a folio
  fs: Change try_to_free_buffers() to take a folio
  jbd2: Convert release_buffer_page() to use a folio
  jbd2: Convert jbd2_journal_try_to_free_buffers to take a folio
  reiserfs: Convert release_buffer_page() to use a folio
  fs: Remove last vestiges of releasepage
  ubifs: Convert to release_folio
  reiserfs: Convert to release_folio
  orangefs: Convert to release_folio
  ocfs2: Convert to release_folio
  nilfs2: Remove comment about releasepage
  nfs: Convert to release_folio
  jfs: Convert to release_folio
  ...

1 files changed, 6 insertions, 4 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 7e2da284e427..fa1117db4610 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2602,10 +2602,12 @@ EXPORT_SYMBOL(folio_redirty_for_writepage);
  * folio_mark_dirty - Mark a folio as being modified.
  * @folio: The folio.
  *
- * For folios with a mapping this should be done with the folio lock held
- * for the benefit of asynchronous memory errors who prefer a consistent
- * dirty state. This rule can be broken in some special cases,
- * but should be better not to.
+ * The folio may not be truncated while this function is running.
+ * Holding the folio lock is sufficient to prevent truncation, but some
+ * callers cannot acquire a sleeping lock.  These callers instead hold
+ * the page table lock for a page table which contains at least one page
+ * in this folio.  Truncation will block on the page table lock as it
+ * unmaps pages before removing the folio from its mapping.
  *
  * Return: True if the folio was newly dirtied, false if it was already dirty.
  */