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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230724094354.90817-33-zhengqi.arch@bytedance.com>
Date: Mon, 24 Jul 2023 17:43:39 +0800
From: Qi Zheng <zhengqi.arch@...edance.com>
To: akpm@...ux-foundation.org,
	david@...morbit.com,
	tkhai@...ru,
	vbabka@...e.cz,
	roman.gushchin@...ux.dev,
	djwong@...nel.org,
	brauner@...nel.org,
	paulmck@...nel.org,
	tytso@....edu,
	steven.price@....com,
	cel@...nel.org,
	senozhatsky@...omium.org,
	yujie.liu@...el.com,
	gregkh@...uxfoundation.org,
	muchun.song@...ux.dev
Cc: linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	x86@...nel.org,
	kvm@...r.kernel.org,
	xen-devel@...ts.xenproject.org,
	linux-erofs@...ts.ozlabs.org,
	linux-f2fs-devel@...ts.sourceforge.net,
	cluster-devel@...hat.com,
	linux-nfs@...r.kernel.org,
	linux-mtd@...ts.infradead.org,
	rcu@...r.kernel.org,
	netdev@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	linux-arm-msm@...r.kernel.org,
	dm-devel@...hat.com,
	linux-raid@...r.kernel.org,
	linux-bcache@...r.kernel.org,
	virtualization@...ts.linux-foundation.org,
	linux-fsdevel@...r.kernel.org,
	linux-ext4@...r.kernel.org,
	linux-xfs@...r.kernel.org,
	linux-btrfs@...r.kernel.org,
	Qi Zheng <zhengqi.arch@...edance.com>
Subject: [PATCH v2 32/47] ext4: dynamically allocate the ext4-es shrinker

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@...edance.com>
---
 fs/ext4/ext4.h           |  2 +-
 fs/ext4/extents_status.c | 22 ++++++++++++----------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 0a2d55faa095..1bd150d454f5 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1651,7 +1651,7 @@ 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 9b5b8951afb4..8d4a959dd32f 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -1596,7 +1596,7 @@ 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;
@@ -1605,8 +1605,7 @@ 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;
 
@@ -1690,14 +1689,17 @@ 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)
 		goto err4;
 
+	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;
+	sbi->s_es_shrinker->private_data = sbi;
+
+	shrinker_register(sbi->s_es_shrinker);
+
 	return 0;
 err4:
 	percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
@@ -1716,7 +1718,7 @@ 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_unregister(sbi->s_es_shrinker);
 }
 
 /*
-- 
2.30.2