[Cluster-devel] switch iomap to an iterator model v2

[Christoph Hellwig]

Hi all,

this series replies the existing callback-based iomap_apply to an iter based
model.  The prime aim here is to simply the DAX reflink support, which
requires iterating through two inodes, something that is rather painful
with the apply model.  It also helps to kill an indirect call per segment
as-is.  Compared to the earlier patchset from Matthew Wilcox that this
series is based upon it does not eliminate all indirect calls, but as the
upside it does not change the file systems at all (except for the btrfs
and gfs2 hooks which have slight prototype changes).


Changes since v1:
 - rebased to the lastes iomap-for-next tree
 - rename iter.c to core.c
 - turn iomap_iter.processed into a s64
 - rename a few variables
 - error out instead of just warn when a loop processed too much data
 - fix the readpage iter return value for inline data
 - better document the iomap_iter() calling conventions

Diffstat:
 b/fs/btrfs/inode.c       |    5 
 b/fs/buffer.c            |    4 
 b/fs/dax.c               |  578 ++++++++++++++++++++++-------------------------
 b/fs/gfs2/bmap.c         |    5 
 b/fs/internal.h          |    4 
 b/fs/iomap/Makefile      |    2 
 b/fs/iomap/buffered-io.c |  359 +++++++++++++----------------
 b/fs/iomap/core.c        |   79 ++++++
 b/fs/iomap/direct-io.c   |  164 ++++++-------
 b/fs/iomap/fiemap.c      |  101 +++-----
 b/fs/iomap/seek.c        |   98 ++++---
 b/fs/iomap/swapfile.c    |   38 +--
 b/fs/iomap/trace.h       |   35 +-
 b/include/linux/iomap.h  |   77 ++++--
 fs/iomap/apply.c         |   99 --------
 15 files changed, 799 insertions(+), 849 deletions(-)