From 1f1d459c9a2f0c8618b137fe845c09e405ae59fc Mon Sep 17 00:00:00 2001 From: Qi Zheng Date: Mon, 11 Sep 2023 17:44:22 +0800 Subject: [PATCH] dm: dynamically allocate the dm-bufio shrinker In preparation for implementing lockless slab shrink, use new APIs to dynamically allocate the dm-bufio 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 dm_bufio_client. Link: https://lkml.kernel.org/r/20230911094444.68966-24-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Reviewed-by: Muchun Song Cc: Alasdair Kergon Cc: Mike Snitzer Cc: Abhinav Kumar Cc: Alexander Viro Cc: Alyssa Rosenzweig Cc: Andreas Dilger Cc: Andreas Gruenbacher Cc: Anna Schumaker Cc: Arnd Bergmann Cc: Bob Peterson Cc: Borislav Petkov Cc: Carlos Llamas Cc: Chandan Babu R Cc: Chao Yu Cc: Chris Mason Cc: Christian Brauner Cc: Christian Koenig Cc: Chuck Lever Cc: Coly Li Cc: Dai Ngo Cc: Daniel Vetter Cc: Daniel Vetter Cc: "Darrick J. Wong" Cc: Dave Chinner Cc: Dave Hansen Cc: David Airlie Cc: David Hildenbrand Cc: David Sterba Cc: Dmitry Baryshkov Cc: Gao Xiang Cc: Greg Kroah-Hartman Cc: Huang Rui Cc: Ingo Molnar Cc: Jaegeuk Kim Cc: Jani Nikula Cc: Jan Kara Cc: Jason Wang Cc: Jeff Layton Cc: Jeffle Xu Cc: Joel Fernandes (Google) Cc: Joonas Lahtinen Cc: Josef Bacik Cc: Juergen Gross Cc: Kent Overstreet Cc: Kirill Tkhai Cc: Marijn Suijten Cc: "Michael S. Tsirkin" Cc: Minchan Kim Cc: Muchun Song Cc: Nadav Amit Cc: Neil Brown Cc: Oleksandr Tyshchenko Cc: Olga Kornievskaia Cc: Paul E. McKenney Cc: Richard Weinberger Cc: Rob Clark Cc: Rob Herring Cc: Rodrigo Vivi Cc: Roman Gushchin Cc: Sean Paul Cc: Sergey Senozhatsky Cc: Song Liu Cc: Stefano Stabellini Cc: Steven Price Cc: "Theodore Ts'o" Cc: Thomas Gleixner Cc: Tomeu Vizoso Cc: Tom Talpey Cc: Trond Myklebust Cc: Tvrtko Ursulin Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: Yue Hu Signed-off-by: Andrew Morton --- drivers/md/dm-bufio.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index bc309e41d074..62eb27639c9b 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -963,7 +963,7 @@ struct dm_bufio_client { sector_t start; - struct shrinker shrinker; + struct shrinker *shrinker; struct work_struct shrink_work; atomic_long_t need_shrink; @@ -2368,7 +2368,7 @@ static unsigned long dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink { struct dm_bufio_client *c; - c = container_of(shrink, struct dm_bufio_client, shrinker); + c = shrink->private_data; atomic_long_add(sc->nr_to_scan, &c->need_shrink); queue_work(dm_bufio_wq, &c->shrink_work); @@ -2377,7 +2377,7 @@ static unsigned long dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink static unsigned long dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc) { - struct dm_bufio_client *c = container_of(shrink, struct dm_bufio_client, shrinker); + struct dm_bufio_client *c = shrink->private_data; unsigned long count = cache_total(&c->cache); unsigned long retain_target = get_retain_buffers(c); unsigned long queued_for_cleanup = atomic_long_read(&c->need_shrink); @@ -2490,14 +2490,20 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign INIT_WORK(&c->shrink_work, shrink_work); atomic_long_set(&c->need_shrink, 0); - c->shrinker.count_objects = dm_bufio_shrink_count; - c->shrinker.scan_objects = dm_bufio_shrink_scan; - c->shrinker.seeks = 1; - c->shrinker.batch = 0; - r = register_shrinker(&c->shrinker, "dm-bufio:(%u:%u)", - MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev)); - if (r) + c->shrinker = shrinker_alloc(0, "dm-bufio:(%u:%u)", + MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev)); + if (!c->shrinker) { + r = -ENOMEM; goto bad; + } + + c->shrinker->count_objects = dm_bufio_shrink_count; + c->shrinker->scan_objects = dm_bufio_shrink_scan; + c->shrinker->seeks = 1; + c->shrinker->batch = 0; + c->shrinker->private_data = c; + + shrinker_register(c->shrinker); mutex_lock(&dm_bufio_clients_lock); dm_bufio_client_count++; @@ -2537,7 +2543,7 @@ void dm_bufio_client_destroy(struct dm_bufio_client *c) drop_buffers(c); - unregister_shrinker(&c->shrinker); + shrinker_free(c->shrinker); flush_work(&c->shrink_work); mutex_lock(&dm_bufio_clients_lock);