user/sven/linux.git/drivers/md/persistent-data, branch v4.9.103

dm btree: fix serious bug in btree_split_beneath()

2018-01-23T18:57:08Z

commit bc68d0a43560e950850fc69b58f0f8254b28f6d6 upstream. When inserting a new key/value pair into a btree we walk down the spine of btree nodes performing the following 2 operations: i) space for a new entry ii) adjusting the first key entry if the new key is lower than any in the node. If the _root_ node is full, the function btree_split_beneath() allocates 2 new nodes, and redistibutes the root nodes entries between them. The root node is left with 2 entries corresponding to the 2 new nodes. btree_split_beneath() then adjusts the spine to point to one of the two new children. This means the first key is never adjusted if the new key was lower, ie. operation (ii) gets missed out. This can result in the new key being 'lost' for a period; until another low valued key is inserted that will uncover it. This is a serious bug, and quite hard to make trigger in normal use. A reproducing test case ("thin create devices-in-reverse-order") is available as part of the thin-provision-tools project: https://github.com/jthornber/thin-provisioning-tools/blob/master/functional-tests/device-mapper/dm-tests.scm#L593 Fix the issue by changing btree_split_beneath() so it no longer adjusts the spine. Instead it unlocks both the new nodes, and lets the main loop in btree_insert_raw() relock the appropriate one and make any neccessary adjustments. Reported-by: Monty Pavel Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm space map disk: fix some book keeping in the disk space map

2017-05-25T13:44:33Z

commit 0377a07c7a035e0d033cd8b29f0cb15244c0916a upstream. When decrementing the reference count for a block, the free count wasn't being updated if the reference count went to zero. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm btree: fix for dm_btree_find_lowest_key()

2017-05-25T13:44:32Z

commit 7d1fedb6e96a960aa91e4ff70714c3fb09195a5a upstream. dm_btree_find_lowest_key() is giving incorrect results. find_key() traverses the btree correctly for finding the highest key, but there is an error in the way it traverses the btree for retrieving the lowest key. dm_btree_find_lowest_key() fetches the first key of the rightmost block of the btree instead of fetching the first key from the leftmost block. Fix this by conditionally passing the correct parameter to value64() based on the @find_highest flag. Signed-off-by: Erez Zadok Signed-off-by: Vinothkumar Raja Signed-off-by: Nidhi Panpalia Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm space map metadata: fix 'struct sm_metadata' leak on failed create

2017-01-06T09:40:16Z

commit 314c25c56c1ee5026cf99c570bdfe01847927acb upstream. In dm_sm_metadata_create() we temporarily change the dm_space_map operations from 'ops' (whose .destroy function deallocates the sm_metadata) to 'bootstrap_ops' (whose .destroy function doesn't). If dm_sm_metadata_create() fails in sm_ll_new_metadata() or sm_ll_extend(), it exits back to dm_tm_create_internal(), which calls dm_sm_destroy() with the intention of freeing the sm_metadata, but it doesn't (because the dm_space_map operations is still set to 'bootstrap_ops'). Fix this by setting the dm_space_map operations back to 'ops' if dm_sm_metadata_create() fails when it is set to 'bootstrap_ops'. Signed-off-by: Benjamin Marzinski Acked-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm array: introduce cursor api

2016-09-22T15:15:04Z

More efficient way to iterate an array due to prefetching (makes use of the new dm_btree_cursor_* api). Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm btree: introduce cursor api

2016-09-22T15:15:04Z

This uses prefetching to speed up iteration through a btree. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm array: add dm_array_new()

2016-09-22T15:12:23Z

dm_array_new() creates a new, populated array more efficiently than starting with an empty one and resizing. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm btree: fix a bug in dm_btree_find_next_single()

2016-07-20T16:43:34Z

dm_btree_find_next_single() can short-circuit the search for a block with a return of -ENODATA if all entries are higher than the search key passed to lower_bound(). This hasn't been a problem because of the way the btree has been used by DM thinp. But it must be fixed now in preparation for fixing the race in DM thinp's handling of simultaneous block discard vs allocation. Otherwise, once that fix is in place, some of the blocks in a discard would not be unmapped as expected. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm space map metadata: remove unused variable in brb_pop()

2015-12-14T14:26:01Z

Remove the unused struct block_op pointer that was inadvertantly introduced, via cut-and-paste of previous brb_op() code, as part of commit 50dd842ad. (Cc'ing stable@ because commit 50dd842ad did) Fixes: 50dd842ad ("dm space map metadata: fix ref counting bug when bootstrapping a new space map") Reported-by: David Binderman Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org

dm btree: factor out need_insert() helper

2015-12-10T15:38:59Z

Eliminates code duplication within insert(). Signed-off-by: Mike Snitzer