[PATCH 0/4] btrfs: refactor btrfs_buffered_write() for the incoming large data folios

[Qu Wenruo <wqu@suse.com>]

The function btrfs_buffered_write() is implementing all the complex
heavy-lifting work inside a huge while () loop, which makes later large
data folios work much harder.

The first patch is a patch that already submitted to the mailing list
recently, but all later reworks depends on that patch, thus it is
included in the series.

The core of the whole series is to introduce a helper function,
copy_one_range() to do the buffer copy into one single folio.

Patch 2 is a preparation that moves the error cleanup into the main loop,
so we do not have dedicated out-of-loop cleanup.

Patch 3 is another preparation that extract the space reservation code
into a helper, make the final refactor patch a little more smaller.

And patch 4 is the main dish, with all the refactoring happening inside
it.

Qu Wenruo (4):
  btrfs: remove force_page_uptodate variable from btrfs_buffered_write()
  btrfs: cleanup the reserved space inside the loop of
    btrfs_buffered_write()
  btrfs: extract the space reservation code from btrfs_buffered_write()
  btrfs: extract the main loop of btrfs_buffered_write() into a helper

 fs/btrfs/file.c | 434 ++++++++++++++++++++++++++----------------------
 1 file changed, 231 insertions(+), 203 deletions(-)

-- 
2.49.0