From 7a0bc2a8966040d54289b64842d55e2cf4343ad9 Mon Sep 17 00:00:00 2001
From: Coly Li <colyli@suse.de>
Date: Fri, 24 Jan 2020 01:01:36 +0800
Subject: [PATCH] bcache: add code comments for state->pool in __btree_sort()
Git-commit: 7a0bc2a8966040d54289b64842d55e2cf4343ad9
Patch-mainline: v5.6-rc1
References: bsc#1163762
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>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
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