[PATCH 0/3] xfs: a few reflink cowblocks fixes

[Brian Foster <bfoster@redhat.com>]

This is just a few reflink fixes associated with cowblocks tagging that
I came across when playing around with and/or reviewing some code. The
issue associated with patch 3 is easily reproducible with something like
the following:

	echo 30 > /proc/sys/fs/xfs/speculative_cow_prealloc_lifetime

	xfs_io -fc "cowextsize 64k" $src
	xfs_io -c "pwrite 0 128k" $src
	cp --reflink $src $tgt

	xfs_io -c "pwrite 64k 32k" $tgt
	xfs_io -c "pwrite 96k 32k" $tgt
	echo sleep
	sleep 25
	echo delalloc
	xfs_io -c "pwrite 0 4k" $tgt

... which basically just sets the cowblocks tag, uses up all of the
resulting cow blocks, waits until just before the cowblocks scanner is
going to run and creates a delalloc reservation in the cow fork. The cow
fork fiemap thingy I sent the other day shows that the resulting cow
fork blocks remain indefinitely.

Thoughts, reviews, flames appreciated.

Brian

Brian Foster (3):
  xfs: fix up inode cowblocks tracking tracepoints
  xfs: clear cowblocks tag when cow fork is emptied
  xfs: don't skip cow forks w/ delalloc blocks in cowblocks scan

 fs/xfs/xfs_icache.c  | 10 +++++-----
 fs/xfs/xfs_reflink.c | 29 +++++++++--------------------
 fs/xfs/xfs_reflink.h |  2 +-
 3 files changed, 15 insertions(+), 26 deletions(-)

-- 
2.7.4