osd: remove magical tmap -> omap conversionwip-tmap

This is incomplete and unfortunately unusable in its current state:

 - it would only set USES_TMAP for old encoded object_info_t and tmapput,
   but would NOT set it for tmapup
 - a config option turned that off by default.

That means that the mds conversion from tmap -> omap won't be able to use
this because any existing cluster has tmap objects without the USES_TMAP
flag set.  And we don't want to unconditionally try a tmap->omap conversion
on omap operations because there are lots of existing librados users out
there that will be negatively impacted by this.

Instead, the MDS will need to handle this conversion on the client side by
reading either tmap or omap objects and explicitly rewriting the content
with omap (while truncating the tmap data away).

The auto-conversion function was added in v0.44.

Signed-off-by: Sage Weil <sage@inktank.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/PendingReleaseNotes b/PendingReleaseNotes
index 7d667f3ff59..725e02e0a3a 100644
--- a/PendingReleaseNotes
+++ b/PendingReleaseNotes
@@ -1,3 +1,15 @@
 v0.70
 ~~~~~
-mds: disable adding snapshots by default. (re-enable them with "ceph mds allow_snaps")
\ No newline at end of file
+
+* The MDS now disallows snapshots by default as they are not
+  considered stable.  The command 'ceph mds set allow_snaps' will
+  enable them.
+
+* For clusters that were created before v0.44 (pre-argonaut, Spring
+  2012) and store radosgw data, the auto-upgrade from TMAP to OMAP
+  objects has been disabled.  Before upgrading, make sure that any
+  buckets created on pre-argonaut releases have been modified (e.g.,
+  by PUTing and then DELETEing an object from each bucket).  Any
+  cluster created with argonaut (v0.48) or a later release or not
+  using radosgw never relied on the automatic conversion and is not
+  affected by this change.