From 8eea99a81c6f67c08fedd7db2ccd09aa93db69a7 Mon Sep 17 00:00:00 2001 From: Qi Zheng Date: Mon, 11 Sep 2023 17:44:32 +0800 Subject: [PATCH] nfsd: dynamically allocate the nfsd-reply shrinker In preparation for implementing lockless slab shrink, use new APIs to dynamically allocate the nfsd-reply 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 nfsd_net. Link: https://lkml.kernel.org/r/20230911094444.68966-34-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Acked-by: Chuck Lever Acked-by: Jeff Layton Acked-by: Muchun Song Cc: Neil Brown Cc: Olga Kornievskaia Cc: Dai Ngo Cc: Tom Talpey Cc: Abhinav Kumar Cc: Alasdair Kergon 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: 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: 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: Mike Snitzer Cc: Minchan Kim Cc: Nadav Amit Cc: Oleksandr Tyshchenko 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: Trond Myklebust Cc: Tvrtko Ursulin Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: Yue Hu Signed-off-by: Andrew Morton --- fs/nfsd/netns.h | 2 +- fs/nfsd/nfscache.c | 31 ++++++++++++++++--------------- 2 files changed, 17 insertions(+), 16 deletions(-) diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index f669444d5336..ab303a8b77d5 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -177,7 +177,7 @@ struct nfsd_net { /* size of cache when we saw the longest hash chain */ unsigned int longest_chain_cachesize; - struct shrinker nfsd_reply_cache_shrinker; + struct shrinker *nfsd_reply_cache_shrinker; /* tracking server-to-server copy mounts */ spinlock_t nfsd_ssc_lock; diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index 80621a709510..fd56a52aa5fb 100644 --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -201,26 +201,29 @@ int nfsd_reply_cache_init(struct nfsd_net *nn) { unsigned int hashsize; unsigned int i; - int status = 0; nn->max_drc_entries = nfsd_cache_size_limit(); atomic_set(&nn->num_drc_entries, 0); hashsize = nfsd_hashsize(nn->max_drc_entries); nn->maskbits = ilog2(hashsize); - nn->nfsd_reply_cache_shrinker.scan_objects = nfsd_reply_cache_scan; - nn->nfsd_reply_cache_shrinker.count_objects = nfsd_reply_cache_count; - nn->nfsd_reply_cache_shrinker.seeks = 1; - status = register_shrinker(&nn->nfsd_reply_cache_shrinker, - "nfsd-reply:%s", nn->nfsd_name); - if (status) - return status; - nn->drc_hashtbl = kvzalloc(array_size(hashsize, sizeof(*nn->drc_hashtbl)), GFP_KERNEL); if (!nn->drc_hashtbl) + return -ENOMEM; + + nn->nfsd_reply_cache_shrinker = shrinker_alloc(0, "nfsd-reply:%s", + nn->nfsd_name); + if (!nn->nfsd_reply_cache_shrinker) goto out_shrinker; + nn->nfsd_reply_cache_shrinker->scan_objects = nfsd_reply_cache_scan; + nn->nfsd_reply_cache_shrinker->count_objects = nfsd_reply_cache_count; + nn->nfsd_reply_cache_shrinker->seeks = 1; + nn->nfsd_reply_cache_shrinker->private_data = nn; + + shrinker_register(nn->nfsd_reply_cache_shrinker); + for (i = 0; i < hashsize; i++) { INIT_LIST_HEAD(&nn->drc_hashtbl[i].lru_head); spin_lock_init(&nn->drc_hashtbl[i].cache_lock); @@ -229,7 +232,7 @@ int nfsd_reply_cache_init(struct nfsd_net *nn) return 0; out_shrinker: - unregister_shrinker(&nn->nfsd_reply_cache_shrinker); + kvfree(nn->drc_hashtbl); printk(KERN_ERR "nfsd: failed to allocate reply cache\n"); return -ENOMEM; } @@ -239,7 +242,7 @@ void nfsd_reply_cache_shutdown(struct nfsd_net *nn) struct nfsd_cacherep *rp; unsigned int i; - unregister_shrinker(&nn->nfsd_reply_cache_shrinker); + shrinker_free(nn->nfsd_reply_cache_shrinker); for (i = 0; i < nn->drc_hashsize; i++) { struct list_head *head = &nn->drc_hashtbl[i].lru_head; @@ -323,8 +326,7 @@ nfsd_prune_bucket_locked(struct nfsd_net *nn, struct nfsd_drc_bucket *b, static unsigned long nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc) { - struct nfsd_net *nn = container_of(shrink, - struct nfsd_net, nfsd_reply_cache_shrinker); + struct nfsd_net *nn = shrink->private_data; return atomic_read(&nn->num_drc_entries); } @@ -343,8 +345,7 @@ nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc) static unsigned long nfsd_reply_cache_scan(struct shrinker *shrink, struct shrink_control *sc) { - struct nfsd_net *nn = container_of(shrink, - struct nfsd_net, nfsd_reply_cache_shrinker); + struct nfsd_net *nn = shrink->private_data; unsigned long freed = 0; LIST_HEAD(dispose); unsigned int i; -- 2.49.0