diff mbox series

[v6,30/45] ext4: dynamically allocate the ext4-es shrinker

Message ID 20230911094444.68966-31-zhengqi.arch@bytedance.com (mailing list archive)
State New
Headers show
Series use refcount+RCU method to implement lockless slab shrink | expand

Commit Message

Qi Zheng Sept. 11, 2023, 9:44 a.m. UTC 
In preparation for implementing lockless slab shrink, use new APIs to
dynamically allocate the ext4-es shrinker, so that it can be freed
asynchronously via 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@bytedance.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
CC: "Theodore Ts'o" <tytso@mit.edu>
CC: Andreas Dilger <adilger.kernel@dilger.ca>
CC: linux-ext4@vger.kernel.org
---
 fs/ext4/ext4.h           |  2 +-
 fs/ext4/extents_status.c | 23 +++++++++++++----------
 2 files changed, 14 insertions(+), 11 deletions(-)
diff mbox series

Patch

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 9418359b1d9d..8eeff770992c 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1653,7 +1653,7 @@  struct ext4_sb_info {
 	__u32 s_csum_seed;
 
 	/* Reclaim extents from extent status tree */
-	struct shrinker s_es_shrinker;
+	struct shrinker *s_es_shrinker;
 	struct list_head s_es_list;	/* List of inodes with reclaimable extents */
 	long s_es_nr_inode;
 	struct ext4_es_stats s_es_stats;
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 6f7de14c0fa8..deec7d1f4e50 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -1606,7 +1606,7 @@  static unsigned long ext4_es_count(struct shrinker *shrink,
 	unsigned long nr;
 	struct ext4_sb_info *sbi;
 
-	sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker);
+	sbi = shrink->private_data;
 	nr = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
 	trace_ext4_es_shrink_count(sbi->s_sb, sc->nr_to_scan, nr);
 	return nr;
@@ -1615,8 +1615,7 @@  static unsigned long ext4_es_count(struct shrinker *shrink,
 static unsigned long ext4_es_scan(struct shrinker *shrink,
 				  struct shrink_control *sc)
 {
-	struct ext4_sb_info *sbi = container_of(shrink,
-					struct ext4_sb_info, s_es_shrinker);
+	struct ext4_sb_info *sbi = shrink->private_data;
 	int nr_to_scan = sc->nr_to_scan;
 	int ret, nr_shrunk;
 
@@ -1700,13 +1699,17 @@  int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
 	if (err)
 		goto err3;
 
-	sbi->s_es_shrinker.scan_objects = ext4_es_scan;
-	sbi->s_es_shrinker.count_objects = ext4_es_count;
-	sbi->s_es_shrinker.seeks = DEFAULT_SEEKS;
-	err = register_shrinker(&sbi->s_es_shrinker, "ext4-es:%s",
-				sbi->s_sb->s_id);
-	if (err)
+	sbi->s_es_shrinker = shrinker_alloc(0, "ext4-es:%s", sbi->s_sb->s_id);
+	if (!sbi->s_es_shrinker) {
+		err = -ENOMEM;
 		goto err4;
+	}
+
+	sbi->s_es_shrinker->scan_objects = ext4_es_scan;
+	sbi->s_es_shrinker->count_objects = ext4_es_count;
+	sbi->s_es_shrinker->private_data = sbi;
+
+	shrinker_register(sbi->s_es_shrinker);
 
 	return 0;
 err4:
@@ -1726,7 +1729,7 @@  void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi)
 	percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses);
 	percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
 	percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
-	unregister_shrinker(&sbi->s_es_shrinker);
+	shrinker_free(sbi->s_es_shrinker);
 }
 
 /*