[PATCH v2 32/47] ext4: dynamically allocate the ext4-es shrinker

[Muchun Song]

> On Jul 24, 2023, at 17:43, Qi Zheng <zhengqi.arch at bytedance.com> wrote:
> 
> In preparation for implementing lockless slab shrink, use new APIs to
> dynamically allocate the ext4-es shrinker, so that it can be freed
> asynchronously using kfree_rcu(). Then it doesn't need to wait for RCU
> read-side critical section when releasing the struct ext4_sb_info.
> 
> Signed-off-by: Qi Zheng <zhengqi.arch at bytedance.com>

Reviewed-by: Muchun Song <songmuchun at bytedance.com>