[0/3] Add folio_zero_tail() and folio_fill_tail()

Message

Matthew Wilcox Nov. 7, 2023, 9:26 p.m. UTC

I'm trying to make it easier for filesystems with tailpacking /
stuffing / inline data to use folios.  The primary function here is
folio_fill_tail().  You give it a pointer to memory where the data
currently is, and it takes care of copying it into the folio at that
offset.  That works for gfs2 & iomap.  Then There's Ext4.  Rather than
gin up some kind of specialist "Here's a two pointers to two blocks
of memory" routine, just let it do its current thing, and let it call
folio_zero_tail(), which is also called by folio_fill_tail().

Other filesystems can be converted later; these ones seemed like good
examples as they're already partly or completely converted to folios.

Matthew Wilcox (Oracle) (3):
  mm: Add folio_zero_tail() and use it in ext4
  mm: Add folio_fill_tail() and use it in iomap
  gfs2: Convert stuffed_readpage() to stuffed_read_folio()

 fs/ext4/inline.c        |  3 +-
 fs/gfs2/aops.c          | 37 +++++++++-----------
 fs/iomap/buffered-io.c  | 14 ++------
 include/linux/highmem.h | 76 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 96 insertions(+), 34 deletions(-)