[PATCH 0/5] btrfs: dedupe fixes, features V5

[Mark Fasheh <mfasheh@suse.de>]

Hi Chris,

   The following patches are based on top of my patch titled "btrfs:
Handle unaligned length in extent_same" which you have in your
'integration-4.2' branch:

https://git.kernel.org/cgit/linux/kernel/git/mason/linux-btrfs.git/commit/?id=e1d227a42ea2b4664f94212bd1106b9a3413ffb8

The series contains three fixes and two features.

The first patch in the series fixes a bug where we were sometimes
passing the aligned length to our comparison function. We actually can
stop at the user passed length for this as we don't need to compare
data past i_size (and we only align if the extents go out to i_size).

The 2nd patch fixes a deadlock between btrfs readpage and
btrfs_extent_same. This was reported on the list some months ago -
basically we had the page and extent locking reversed. My patch fixes
up the locking to be in the right order.

The 3rd patch fixes a deadlocks in clone() (wrt extent-same) which
David found while reviewing my fixes. I also found that clone doesn't
lock extent ranges in any particular order which could obvioulsy be a
problem so that is fixed there too.

The last two patches add features which have been requested often by
users - the 4th adds the ability to dedupe within the same inode, and
the last patch fixes up the clone code to skip updating mtime and
ctime when called from extent-same (this helps with backup software
which is being confused into re-backing up deduped files).


Changes from V4 to V5:
  - don't update ctime either in patch #5

Changes from V3 to V4:
  - change mtime patch from a flag to default behavior

Changes from V2 to V3:
  - better flag naming in patch #5, thanks to David

Changes from V1 to V2:
  - added patches 3-5

Thanks,
   --Mark