From d17452aa33a6fd0e9cf2bd3d43237f2d2c294a7e Mon Sep 17 00:00:00 2001 From: Qi Zheng Date: Mon, 11 Sep 2023 17:44:31 +0800 Subject: [PATCH] nfsd: dynamically allocate the nfsd-client shrinker In preparation for implementing lockless slab shrink, use new APIs to dynamically allocate the nfsd-client 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/20230911094444.68966-33-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Acked-by: Chuck Lever Acked-by: Jeff Layton Cc: Jeff Layton 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: Muchun Song Cc: Muchun Song Cc: Nadav Amit Cc: Neil Brown 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/nfs4state.c | 19 +++++++++++-------- 2 files changed, 12 insertions(+), 9 deletions(-) diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index ec49b200b797..f669444d5336 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -195,7 +195,7 @@ struct nfsd_net { int nfs4_max_clients; atomic_t nfsd_courtesy_clients; - struct shrinker nfsd_client_shrinker; + struct shrinker *nfsd_client_shrinker; struct work_struct nfsd_shrinker_work; }; diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 8534693eb6a4..23b3b38c8cda 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -4400,8 +4400,7 @@ static unsigned long nfsd4_state_shrinker_count(struct shrinker *shrink, struct shrink_control *sc) { int count; - struct nfsd_net *nn = container_of(shrink, - struct nfsd_net, nfsd_client_shrinker); + struct nfsd_net *nn = shrink->private_data; count = atomic_read(&nn->nfsd_courtesy_clients); if (!count) @@ -8149,12 +8148,16 @@ static int nfs4_state_create_net(struct net *net) INIT_WORK(&nn->nfsd_shrinker_work, nfsd4_state_shrinker_worker); get_net(net); - nn->nfsd_client_shrinker.scan_objects = nfsd4_state_shrinker_scan; - nn->nfsd_client_shrinker.count_objects = nfsd4_state_shrinker_count; - nn->nfsd_client_shrinker.seeks = DEFAULT_SEEKS; - - if (register_shrinker(&nn->nfsd_client_shrinker, "nfsd-client")) + nn->nfsd_client_shrinker = shrinker_alloc(0, "nfsd-client"); + if (!nn->nfsd_client_shrinker) goto err_shrinker; + + nn->nfsd_client_shrinker->scan_objects = nfsd4_state_shrinker_scan; + nn->nfsd_client_shrinker->count_objects = nfsd4_state_shrinker_count; + nn->nfsd_client_shrinker->private_data = nn; + + shrinker_register(nn->nfsd_client_shrinker); + return 0; err_shrinker: @@ -8252,7 +8255,7 @@ nfs4_state_shutdown_net(struct net *net) struct list_head *pos, *next, reaplist; struct nfsd_net *nn = net_generic(net, nfsd_net_id); - unregister_shrinker(&nn->nfsd_client_shrinker); + shrinker_free(nn->nfsd_client_shrinker); cancel_work(&nn->nfsd_shrinker_work); cancel_delayed_work_sync(&nn->laundromat_work); locks_end_grace(&nn->nfsd4_manager);