[v2,0/5] xfs: properly invalidate cached writeback mapping

Message

Brian Foster Jan. 17, 2019, 7:19 p.m. UTC

Hi all,

Here's v2 of the cached writeback mapping invalidation series. Note that
this post is a bit premature as I'm still testing this code. Christoph
pointed out that he has some patches shifting code around in the same
area so I'm posting what I have under test at this point to hopefully
work out any potential conflicts.

The changes in v2 are basically to beef up the invalidation logic a bit
in xfs_map_blocks() via a new (old) xfs_imap_valid() helper and the
introduction of patch 5, which attempts to add similar mapping
validation in xfs_iomap_write_allocate() to replace the old truncate
detection logic.

Thoughts, reviews, flames appreciated.

Brian

fstest: https://marc.info/?l=fstests&m=154756141122233&w=2

v2:
- Refactor validation logic into xfs_imap_valid() helper.
- Revalidate seqno after the lock cycle in xfs_map_blocks().
- Update *seq in xfs_iomap_write_allocate() regardless of fork type.
- Add patch 5 for seqno revalidation on xfs_iomap_write_allocate() lock
  cycles.
v1: https://marc.info/?l=linux-xfs&m=154721212321112&w=2

Brian Foster (5):
  xfs: eof trim writeback mapping as soon as it is cached
  xfs: update fork seq counter on data fork changes
  xfs: validate writeback mapping using data fork seq counter
  xfs: remove superfluous writeback mapping eof trimming
  xfs: revalidate imap properly before writeback delalloc conversion

 fs/xfs/libxfs/xfs_bmap.c       |  11 ----
 fs/xfs/libxfs/xfs_bmap.h       |   1 -
 fs/xfs/libxfs/xfs_iext_tree.c  |  13 ++--
 fs/xfs/libxfs/xfs_inode_fork.h |   2 +-
 fs/xfs/xfs_aops.c              |  71 ++++++++++++++--------
 fs/xfs/xfs_iomap.c             | 105 ++++++++++++++-------------------
 6 files changed, 98 insertions(+), 105 deletions(-)