[PATCH v4 39/48] xfs: dynamically allocate the xfs-qm shrinker

Qi Zheng
2023-08-07T11:23:59Z

In preparation for implementing lockless slab shrink, use new APIs to
dynamically allocate the xfs-qm 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 xfs_quotainfo.

Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
---
fs/xfs/xfs_qm.c | 28 +++++++++++++++-------------
fs/xfs/xfs_qm.h | 2 +-
2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 6abcc34fafd8..15ba23f11271 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -504,8 +504,7 @@ xfs_qm_shrink_scan(
struct shrinker *shrink,
struct shrink_control *sc)
{
- struct xfs_quotainfo *qi = container_of(shrink,
- struct xfs_quotainfo, qi_shrinker);
+ struct xfs_quotainfo *qi = shrink->private_data;
struct xfs_qm_isolate isol;
unsigned long freed;
int error;
@@ -539,8 +538,7 @@ xfs_qm_shrink_count(
struct shrinker *shrink,
struct shrink_control *sc)
{
- struct xfs_quotainfo *qi = container_of(shrink,
- struct xfs_quotainfo, qi_shrinker);
+ struct xfs_quotainfo *qi = shrink->private_data;

return list_lru_shrink_count(&qi->qi_lru, sc);
}
@@ -680,15 +678,19 @@ xfs_qm_init_quotainfo(
if (XFS_IS_PQUOTA_ON(mp))
xfs_qm_set_defquota(mp, XFS_DQTYPE_PROJ, qinf);

- qinf->qi_shrinker.count_objects = xfs_qm_shrink_count;
- qinf->qi_shrinker.scan_objects = xfs_qm_shrink_scan;
- qinf->qi_shrinker.seeks = DEFAULT_SEEKS;
- qinf->qi_shrinker.flags = SHRINKER_NUMA_AWARE;
-
- error = register_shrinker(&qinf->qi_shrinker, "xfs-qm:%s",
- mp->m_super->s_id);
- if (error)
+ qinf->qi_shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE, "xfs-qm:%s",
+ mp->m_super->s_id);
+ if (!qinf->qi_shrinker) {
+ error = -ENOMEM;
goto out_free_inos;
+ }
+
+ qinf->qi_shrinker->count_objects = xfs_qm_shrink_count;
+ qinf->qi_shrinker->scan_objects = xfs_qm_shrink_scan;
+ qinf->qi_shrinker->seeks = DEFAULT_SEEKS;
+ qinf->qi_shrinker->private_data = qinf;
+
+ shrinker_register(qinf->qi_shrinker);

return 0;

@@ -718,7 +720,7 @@ xfs_qm_destroy_quotainfo(
qi = mp->m_quotainfo;
ASSERT(qi != NULL);

- unregister_shrinker(&qi->qi_shrinker);
+ shrinker_free(qi->qi_shrinker);
list_lru_destroy(&qi->qi_lru);
xfs_qm_destroy_quotainos(qi);
mutex_destroy(&qi->qi_tree_lock);
diff --git a/fs/xfs/xfs_qm.h b/fs/xfs/xfs_qm.h
index 9683f0457d19..d5c9fc4ba591 100644
--- a/fs/xfs/xfs_qm.h
+++ b/fs/xfs/xfs_qm.h
@@ -63,7 +63,7 @@ struct xfs_quotainfo {
struct xfs_def_quota qi_usr_default;
struct xfs_def_quota qi_grp_default;
struct xfs_def_quota qi_prj_default;
- struct shrinker qi_shrinker;
+ struct shrinker *qi_shrinker;

/* Minimum and maximum quota expiration timestamp values. */
time64_t qi_expiry_min;
--
2.30.2