tree d0b28ed29baf20d003061eb096ed1421c431bde4
parent 638ced092ff037955c1451c835cb4ad54bbc6082
author Ming-Hung Tsai <mtsai@redhat.com> 1733211708 +0800
committer Zheng Qixing <zhengqixing@huawei.com> 1733211938 +0800

dm cache: optimize dirty bit checking with find_next_bit when resizing

stable inclusion
from stable-v5.10.230
commit f136d8d3f26fd5113e80ba7c70f7e9a5932295b3
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IB5AV2
CVE: CVE-2024-50278

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f136d8d3f26fd5113e80ba7c70f7e9a5932295b3

--------------------------------

commit f484697e619a83ecc370443a34746379ad99d204 upstream.

When shrinking the fast device, dm-cache iteratively searches for a
dirty bit among the cache blocks to be dropped, which is less efficient.
Use find_next_bit instead, as it is twice as fast as the iterative
approach with test_bit.

Signed-off-by: Ming-Hung Tsai <mtsai@redhat.com>
Fixes: f494a9c6b1b6 ("dm cache: cache shrinking support")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>