BMC/Intel-BMC/linux.git/drivers/md/persistent-data/dm-btree.c, branch dev-4.3

dm btree: fix leak of bufio-backed block in btree_split_sibling error path

2016-02-19T22:28:23+00:00

commit 30ce6e1cc5a0f781d60227e9096c86e188d2c2bd upstream. The block allocated at the start of btree_split_sibling() is never released if later insert_at() fails. Fix this by releasing the previously allocated bufio block using unlock_block(). Reported-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm btree: fix leak of bufio-backed block in btree_split_beneath error path

2015-10-23T18:02:55+00:00

btree_split_beneath()'s error path had an outstanding FIXME that speaks directly to the potential for _not_ cleaning up a previously allocated bufio-backed block. Fix this by releasing the previously allocated bufio block using unlock_block(). Reported-by: Mikulas Patocka Signed-off-by: Mike Snitzer Acked-by: Joe Thornber Cc: stable@vger.kernel.org

dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling()

2015-08-12T15:32:19+00:00

Signed-off-by: Vivek Goyal Signed-off-by: Mike Snitzer

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

2015-08-12T14:50:37+00:00

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 Cc: stable@vger.kernel.org

dm btree: silence lockdep lock inversion in dm_btree_del()

2015-07-06T14:45:02+00:00

Allocate memory using GFP_NOIO when deleting a btree. dm_btree_del() can be called via an ioctl and we don't want to recurse into the FS or block layer. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org

dm btree: fix a recursion depth bug in btree walking code

2014-11-10T20:23:58+00:00

The walk code was using a 'ro_spine' to hold it's locked btree nodes. But this data structure is designed for the rolling lock scheme, and as such automatically unlocks blocks that are two steps up the call chain. This is not suitable for the simple recursive walk algorithm, which retraces its steps. This code is only used by the persistent array code, which in turn is only used by dm-cache. In order to trigger it you need to have a mapping tree that is more than 2 levels deep; which equates to 8-16 million cache blocks. For instance a 4T ssd with a very small block size of 32k only just triggers this bug. The fix just places the locked blocks on the stack, and stops using the ro_spine altogether. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org

dm btree: add dm_btree_find_lowest_key

2014-01-09T21:29:17+00:00

dm_btree_find_lowest_key is the reciprocal of dm_btree_find_highest_key. Factor out common code for dm_btree_find_{highest,lowest}_key. dm_btree_find_lowest_key is needed for an upcoming DM target, as such it is best to get this interface in place. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm btree: prefetch child nodes when walking tree for a dm_btree_del

2013-08-23T13:02:14+00:00

dm-btree now takes advantage of dm-bufio's ability to prefetch data via dm_bm_prefetch(). Prior to this change many btree node visits were causing a synchronous read. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm btree: use pop_frame in dm_btree_del to cleanup code

2013-08-23T13:02:14+00:00

Remove a visited leaf straight away from the stack, rather than marking all it's children as visited and letting it get removed on the next iteration. May also offer a micro optimisation in dm_btree_del. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon

dm persistent data: add btree_walk

2013-03-01T22:45:50+00:00

Add dm_btree_walk to iterate through the contents of a btree. This will be used by the dm cache target. Signed-off-by: Joe Thornber Signed-off-by: Alasdair G Kergon