From: Zizhi Wo <wozizhi@huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IB5UKT -------------------------------- In some functions with wake_up_bit(&cookie->flags, 0), the wake_up depends on removing the cookie from the radix tree, but there is no memory barrier between them. Fix this issue by adding the memory barrier. Fixes: 201a15428bd5 ("FS-Cache: Handle pages pending storage that get evicted under OOM conditions") Signed-off-by: Zizhi Wo <wozizhi@huawei.com> Signed-off-by: Baokun Li <libaokun1@huawei.com> --- fs/fscache/page.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/fscache/page.c b/fs/fscache/page.c index 95490d809b5e..0b5e477cf62b 100644 --- a/fs/fscache/page.c +++ b/fs/fscache/page.c @@ -113,6 +113,8 @@ bool __fscache_maybe_release_page(struct fscache_cookie *cookie, fscache_stat(&fscache_n_store_vmscan_gone); } + /* Make sure the delete operation is performed before waking. */ + smp_mb(); wake_up_bit(&cookie->flags, 0); trace_fscache_wake_cookie(cookie); if (xpage) @@ -171,6 +173,8 @@ static void fscache_end_page_write(struct fscache_object *object, trace_fscache_page(cookie, page, fscache_page_write_end_pend); } spin_unlock(&cookie->stores_lock); + /* Make sure the delete operation is performed before waking. */ + smp_mb(); wake_up_bit(&cookie->flags, 0); trace_fscache_wake_cookie(cookie); } else { @@ -988,6 +992,8 @@ void fscache_invalidate_writes(struct fscache_cookie *cookie) put_page(results[i]); } + /* Make sure the delete operation is performed before waking. */ + smp_mb(); wake_up_bit(&cookie->flags, 0); trace_fscache_wake_cookie(cookie); -- 2.46.1