xavi/android_kernel_m2note/drivers/md/persistent-data/dm-btree-remove.c, branch ng-7.1.2

dm btree remove: fix a bug when rebalancing nodes after removal

2016-08-26T18:46:26+00:00

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 Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman Signed-off-by: Stefan Guendhoer

dm btree: add ref counting ops for the leaves of top level btrees

2016-08-26T18:44:35+00:00

commit b0dc3c8bc157c60b1d470163882be8c13e1950af upstream. When using nested btrees, the top leaves of the top levels contain block addresses for the root of the next tree down. If we shadow a shared leaf node the leaf values (sub tree roots) should be incremented accordingly. This is only an issue if there is metadata sharing in the top levels. Which only occurs if metadata snapshots are being used (as is possible with dm-thinp). And could result in a block from the thinp metadata snap being reused early, thus corrupting the thinp metadata snap. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman Signed-off-by: Stefan Guendhoer

dm btree remove: fix bug in redistribute3

2016-08-26T17:30:12+00:00

commit 4c7e309340ff85072e96f529582d159002c36734 upstream. redistribute3() shares entries out across 3 nodes. Some entries were being moved the wrong way, breaking the ordering. This manifested as a BUG() in dm-btree-remove.c:shift() when entries were removed from the btree. For additional context see: https://www.redhat.com/archives/dm-devel/2015-May/msg00113.html Signed-off-by: Dennis Yang Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman Signed-off-by: Stefan Guendhoer

first commit

2016-08-15T02:19:42+00:00