[PATCH 00/12] Change readahead API

[Matthew Wilcox]

From: "Matthew Wilcox (Oracle)" <willy at infradead.org>

This series adds a readahead address_space operation to eventually
replace the readpages operation.  The key difference is that
pages are added to the page cache as they are allocated (and
then looked up by the filesystem) instead of passing them on a
list to the readpages operation and having the filesystem add
them to the page cache.  It's a net reduction in code for each
implementation, more efficient than walking a list, and solves
the direct-write vs buffered-read problem reported by yu kuai at
https://lore.kernel.org/linux-fsdevel/20200116063601.39201-1-yukuai3@huawei.com/

Matthew Wilcox (Oracle) (12):
  mm: Fix the return type of __do_page_cache_readahead
  readahead: Ignore return value of ->readpages
  readahead: Put pages in cache earlier
  mm: Add readahead address space operation
  fs: Convert mpage_readpages to mpage_readahead
  btrfs: Convert from readpages to readahead
  erofs: Convert uncompressed files from readpages to readahead
  erofs: Convert compressed files from readpages to readahead
  ext4: Convert from readpages to readahead
  f2fs: Convert from readpages to readahead
  fuse: Convert from readpages to readahead
  iomap: Convert from readpages to readahead

 Documentation/filesystems/locking.rst |  7 ++-
 Documentation/filesystems/vfs.rst     | 11 ++++
 drivers/staging/exfat/exfat_super.c   |  9 ++--
 fs/block_dev.c                        |  9 ++--
 fs/btrfs/extent_io.c                  | 15 ++----
 fs/btrfs/extent_io.h                  |  2 +-
 fs/btrfs/inode.c                      | 18 +++----
 fs/erofs/data.c                       | 34 +++++-------
 fs/erofs/zdata.c                      | 21 +++-----
 fs/ext2/inode.c                       | 12 ++---
 fs/ext4/ext4.h                        |  2 +-
 fs/ext4/inode.c                       | 24 ++++-----
 fs/ext4/readpage.c                    | 20 +++----
 fs/f2fs/data.c                        | 33 +++++-------
 fs/fat/inode.c                        |  8 +--
 fs/fuse/file.c                        | 35 ++++++------
 fs/gfs2/aops.c                        | 20 ++++---
 fs/hpfs/file.c                        |  8 +--
 fs/iomap/buffered-io.c                | 74 ++++++--------------------
 fs/iomap/trace.h                      |  2 +-
 fs/isofs/inode.c                      |  9 ++--
 fs/jfs/inode.c                        |  8 +--
 fs/mpage.c                            | 38 +++++---------
 fs/nilfs2/inode.c                     | 13 ++---
 fs/ocfs2/aops.c                       | 32 +++++------
 fs/omfs/file.c                        |  8 +--
 fs/qnx6/inode.c                       |  8 +--
 fs/reiserfs/inode.c                   | 10 ++--
 fs/udf/inode.c                        |  8 +--
 fs/xfs/xfs_aops.c                     | 10 ++--
 include/linux/fs.h                    |  2 +
 include/linux/iomap.h                 |  2 +-
 include/linux/mpage.h                 |  2 +-
 include/linux/pagemap.h               | 12 +++++
 include/trace/events/erofs.h          |  6 +--
 include/trace/events/f2fs.h           |  6 +--
 mm/internal.h                         |  2 +-
 mm/migrate.c                          |  2 +-
 mm/readahead.c                        | 76 +++++++++++++++++----------
 39 files changed, 289 insertions(+), 329 deletions(-)

-- 
2.24.1