[PATCH 00/12] Convert write_cache_pages() to an iterator

[Matthew Wilcox (Oracle)]

Dave Howells doesn't like the indirect function call imposed by
write_cache_pages(), so refactor it into an iterator.  I took the
opportunity to add the ability to iterate a folio_batch without having
an external variable.

This is against next-20230623.  If you try to apply it on top of a tree
which doesn't include the pagevec removal series, IT WILL CRASH because
it won't reinitialise folio_batch->i and the iteration will index out
of bounds.

I have a feeling the 'done' parameter could have a better name, but I
can't think what it might be.

Matthew Wilcox (Oracle) (12):
  writeback: Factor out writeback_finish()
  writeback: Factor writeback_get_batch() out of write_cache_pages()
  writeback: Factor should_writeback_folio() out of write_cache_pages()
  writeback: Simplify the loops in write_cache_pages()
  pagevec: Add ability to iterate a queue
  writeback: Use the folio_batch queue iterator
  writeback: Factor writeback_iter_init() out of write_cache_pages()
  writeback: Factor writeback_get_folio() out of write_cache_pages()
  writeback: Factor writeback_iter_next() out of write_cache_pages()
  writeback: Add for_each_writeback_folio()
  iomap: Convert iomap_writepages() to use for_each_writeback_folio()
  writeback: Remove a use of write_cache_pages() from do_writepages()

 fs/iomap/buffered-io.c    |  14 +-
 include/linux/pagevec.h   |  18 +++
 include/linux/writeback.h |  22 ++-
 mm/page-writeback.c       | 310 +++++++++++++++++++++-----------------
 4 files changed, 216 insertions(+), 148 deletions(-)

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2.39.2