[PATCH 11/17] bcache: add code comments for state->pool in __btree_sort()

colyli
2020-01-23T17:02:57Z

From: Coly Li <colyli@suse.de>

To explain the pages allocated from mempool state->pool can be
swapped in __btree_sort(), because state->pool is a page pool,
which allocates pages by alloc_pages() indeed.

Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/bcache/bset.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index cffcdc9feefb..4385303836d8 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -1257,6 +1257,11 @@ static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
* Our temporary buffer is the same size as the btree node's
* buffer, we can just swap buffers instead of doing a big
* memcpy()
+ *
+ * Don't worry event 'out' is allocated from mempool, it can
+ * still be swapped here. Because state->pool is a page mempool
+ * creaated by by mempool_init_page_pool(), which allocates
+ * pages by alloc_pages() indeed.
*/

out->magic = b->set->data->magic;
--
2.16.4