brd: use page reference to protect page lifetime
authorYu Kuai <yukuai3@huawei.com>
Mon, 11 Aug 2025 06:56:28 +0000 (14:56 +0800)
committerJens Axboe <axboe@kernel.dk>
Mon, 1 Sep 2025 14:37:29 +0000 (08:37 -0600)
commit2a0614522885b136e9e650791c794dd49abb5b31
tree90c19cca1c0ecda19fa69f9ec25ed7e770922259
parent4c7ef92f6d4d08a27d676e4c348f4e2922cab3ed
brd: use page reference to protect page lifetime

As discussed [1], hold rcu for copying data from/to page is too heavy,
it's better to protect page with rcu around for page lookup and then
grab a reference to prevent page to be freed by discard.

[1] https://lore.kernel.org/all/eb41cab3-5946-4fe3-a1be-843dd6fca159@kernel.dk/

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250811065628.1829339-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/block/brd.c