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| author | Joe Thornber <ejt@redhat.com> | 2015-10-21 18:36:49 +0100 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2016-08-26 20:46:26 +0200 |
| commit | 568e6f5bc7577057f6424c351b10b4d24d0a1c47 (patch) | |
| tree | 711bc5245a49400a92a01c2036505f32713f931a /include/linux/patchkey.h | |
| parent | 1dff4a87b3a8d5060a952173ffc7172fcaf2a325 (diff) | |
dm btree remove: fix a bug when rebalancing nodes after removal
commit 2871c69e025e8bc507651d5a9cf81a8a7da9d24b upstream.
Commit 4c7e309340ff ("dm btree remove: fix bug in redistribute3") wasn't
a complete fix for redistribute3().
The redistribute3 function takes 3 btree nodes and shares out the entries
evenly between them. If the three nodes in total contained
(MAX_ENTRIES * 3) - 1 entries between them then this was erroneously getting
rebalanced as (MAX_ENTRIES - 1) on the left and right, and (MAX_ENTRIES + 1) in
the center.
Fix this issue by being more careful about calculating the target number
of entries for the left and right nodes.
Unit tested in userspace using this program:
https://github.com/jthornber/redistribute3-test/blob/master/redistribute3_t.c
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Guendhoer <stefan@guendhoer.com>
Diffstat (limited to 'include/linux/patchkey.h')
0 files changed, 0 insertions, 0 deletions