From patchwork Wed Dec 13 15:23:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 756474 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Cd9uuCRB" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 101D4111 for ; Wed, 13 Dec 2023 07:24:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702481048; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/DyGf3YNSow+1Mki9omJNMosAIv6zOkX5qGi/JSZ9vQ=; b=Cd9uuCRB5VcmZXUqVcD7y4EN7DEptJVjsIexDkk02Cyh5zv2Cegq5XdQH/Jmvsl2OyMtVF bpONbKxbApyMfS8MeUWyLTxnS6lLWSDG6Y7JfhT1lmSgZYEjDgRYReFNCUNUGLgqe22kBK QwnyUTSWvmTGc98uEq8/kADmSa2G4N8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-114-uKlq7dhxPtW50Ig8cODnlQ-1; Wed, 13 Dec 2023 10:24:05 -0500 X-MC-Unique: uKlq7dhxPtW50Ig8cODnlQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 80524101A592; Wed, 13 Dec 2023 15:24:03 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id 32AC740C6EB9; Wed, 13 Dec 2023 15:24:00 +0000 (UTC) From: David Howells To: Jeff Layton , Steve French Cc: David Howells , Matthew Wilcox , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Dominique Martinet , Eric Van Hensbergen , Ilya Dryomov , Christian Brauner , linux-cachefs@redhat.com, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 02/39] netfs, fscache: Combine fscache with netfs Date: Wed, 13 Dec 2023 15:23:12 +0000 Message-ID: <20231213152350.431591-3-dhowells@redhat.com> In-Reply-To: <20231213152350.431591-1-dhowells@redhat.com> References: <20231213152350.431591-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: ceph-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 Now that the fscache code is moved to be colocated with the netfslib code so that they combined into one module, do the combining. Signed-off-by: David Howells cc: Jeff Layton cc: Christian Brauner cc: linux-fsdevel@vger.kernel.org cc: linux-cachefs@redhat.com --- fs/netfs/Kconfig | 4 +- fs/netfs/Makefile | 24 ++-- fs/netfs/fscache_internal.h | 267 +----------------------------------- fs/netfs/fscache_main.c | 17 +-- fs/netfs/internal.h | 192 +++++++++++++++++++++++++- fs/netfs/main.c | 4 +- fs/nfs/Kconfig | 4 +- 7 files changed, 213 insertions(+), 299 deletions(-) diff --git a/fs/netfs/Kconfig b/fs/netfs/Kconfig index b4378688357c..bec805e0c44c 100644 --- a/fs/netfs/Kconfig +++ b/fs/netfs/Kconfig @@ -23,8 +23,8 @@ config NETFS_STATS debugging purposes. Saying 'Y' here is recommended. config FSCACHE - tristate "General filesystem local caching manager" - select NETFS_SUPPORT + bool "General filesystem local caching manager" + depends on NETFS_SUPPORT help This option enables a generic filesystem caching manager that can be used by various network and other filesystems to cache data locally. diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile index bbb2b824bd5e..b57162ef9cfb 100644 --- a/fs/netfs/Makefile +++ b/fs/netfs/Makefile @@ -1,17 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -fscache-y := \ - fscache_cache.o \ - fscache_cookie.o \ - fscache_io.o \ - fscache_main.o \ - fscache_volume.o - -fscache-$(CONFIG_PROC_FS) += fscache_proc.o -fscache-$(CONFIG_FSCACHE_STATS) += fscache_stats.o - -obj-$(CONFIG_FSCACHE) := fscache.o - netfs-y := \ buffered_read.o \ io.o \ @@ -21,4 +9,16 @@ netfs-y := \ netfs-$(CONFIG_NETFS_STATS) += stats.o +netfs-$(CONFIG_FSCACHE) += \ + fscache_cache.o \ + fscache_cookie.o \ + fscache_io.o \ + fscache_main.o \ + fscache_volume.o + +ifeq ($(CONFIG_PROC_FS),y) +netfs-$(CONFIG_FSCACHE) += fscache_proc.o +endif +netfs-$(CONFIG_FSCACHE_STATS) += fscache_stats.o + obj-$(CONFIG_NETFS_SUPPORT) += netfs.o diff --git a/fs/netfs/fscache_internal.h b/fs/netfs/fscache_internal.h index 1336f517e9b1..a09b948fcef2 100644 --- a/fs/netfs/fscache_internal.h +++ b/fs/netfs/fscache_internal.h @@ -5,273 +5,10 @@ * Written by David Howells (dhowells@redhat.com) */ +#include "internal.h" + #ifdef pr_fmt #undef pr_fmt #endif #define pr_fmt(fmt) "FS-Cache: " fmt - -#include -#include -#include -#include -#include - -/* - * cache.c - */ -#ifdef CONFIG_PROC_FS -extern const struct seq_operations fscache_caches_seq_ops; -#endif -bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why); -void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why); -struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache); -void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where); - -static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache) -{ - return smp_load_acquire(&cache->state); -} - -static inline bool fscache_cache_is_live(const struct fscache_cache *cache) -{ - return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE; -} - -static inline void fscache_set_cache_state(struct fscache_cache *cache, - enum fscache_cache_state new_state) -{ - smp_store_release(&cache->state, new_state); - -} - -static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache, - enum fscache_cache_state old_state, - enum fscache_cache_state new_state) -{ - return try_cmpxchg_release(&cache->state, &old_state, new_state); -} - -/* - * cookie.c - */ -extern struct kmem_cache *fscache_cookie_jar; -#ifdef CONFIG_PROC_FS -extern const struct seq_operations fscache_cookies_seq_ops; -#endif -extern struct timer_list fscache_cookie_lru_timer; - -extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix); -extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie, - enum fscache_access_trace why); - -static inline void fscache_see_cookie(struct fscache_cookie *cookie, - enum fscache_cookie_trace where) -{ - trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref), - where); -} - -/* - * main.c - */ -extern unsigned fscache_debug; - -extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len); - -/* - * proc.c - */ -#ifdef CONFIG_PROC_FS -extern int __init fscache_proc_init(void); -extern void fscache_proc_cleanup(void); -#else -#define fscache_proc_init() (0) -#define fscache_proc_cleanup() do {} while (0) -#endif - -/* - * stats.c - */ -#ifdef CONFIG_FSCACHE_STATS -extern atomic_t fscache_n_volumes; -extern atomic_t fscache_n_volumes_collision; -extern atomic_t fscache_n_volumes_nomem; -extern atomic_t fscache_n_cookies; -extern atomic_t fscache_n_cookies_lru; -extern atomic_t fscache_n_cookies_lru_expired; -extern atomic_t fscache_n_cookies_lru_removed; -extern atomic_t fscache_n_cookies_lru_dropped; - -extern atomic_t fscache_n_acquires; -extern atomic_t fscache_n_acquires_ok; -extern atomic_t fscache_n_acquires_oom; - -extern atomic_t fscache_n_invalidates; - -extern atomic_t fscache_n_relinquishes; -extern atomic_t fscache_n_relinquishes_retire; -extern atomic_t fscache_n_relinquishes_dropped; - -extern atomic_t fscache_n_resizes; -extern atomic_t fscache_n_resizes_null; - -static inline void fscache_stat(atomic_t *stat) -{ - atomic_inc(stat); -} - -static inline void fscache_stat_d(atomic_t *stat) -{ - atomic_dec(stat); -} - -#define __fscache_stat(stat) (stat) - -int fscache_stats_show(struct seq_file *m, void *v); -#else - -#define __fscache_stat(stat) (NULL) -#define fscache_stat(stat) do {} while (0) -#define fscache_stat_d(stat) do {} while (0) -#endif - -/* - * volume.c - */ -#ifdef CONFIG_PROC_FS -extern const struct seq_operations fscache_volumes_seq_ops; -#endif - -struct fscache_volume *fscache_get_volume(struct fscache_volume *volume, - enum fscache_volume_trace where); -void fscache_put_volume(struct fscache_volume *volume, - enum fscache_volume_trace where); -bool fscache_begin_volume_access(struct fscache_volume *volume, - struct fscache_cookie *cookie, - enum fscache_access_trace why); -void fscache_create_volume(struct fscache_volume *volume, bool wait); - - -/*****************************************************************************/ -/* - * debug tracing - */ -#define dbgprintk(FMT, ...) \ - printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) - -#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) -#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) -#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) - -#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__) - -#ifdef __KDEBUG -#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) -#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) -#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) - -#elif defined(CONFIG_FSCACHE_DEBUG) -#define _enter(FMT, ...) \ -do { \ - if (__do_kdebug(ENTER)) \ - kenter(FMT, ##__VA_ARGS__); \ -} while (0) - -#define _leave(FMT, ...) \ -do { \ - if (__do_kdebug(LEAVE)) \ - kleave(FMT, ##__VA_ARGS__); \ -} while (0) - -#define _debug(FMT, ...) \ -do { \ - if (__do_kdebug(DEBUG)) \ - kdebug(FMT, ##__VA_ARGS__); \ -} while (0) - -#else -#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) -#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) -#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) -#endif - -/* - * determine whether a particular optional debugging point should be logged - * - we need to go through three steps to persuade cpp to correctly join the - * shorthand in FSCACHE_DEBUG_LEVEL with its prefix - */ -#define ____do_kdebug(LEVEL, POINT) \ - unlikely((fscache_debug & \ - (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3)))) -#define ___do_kdebug(LEVEL, POINT) \ - ____do_kdebug(LEVEL, POINT) -#define __do_kdebug(POINT) \ - ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT) - -#define FSCACHE_DEBUG_CACHE 0 -#define FSCACHE_DEBUG_COOKIE 1 -#define FSCACHE_DEBUG_OBJECT 2 -#define FSCACHE_DEBUG_OPERATION 3 - -#define FSCACHE_POINT_ENTER 1 -#define FSCACHE_POINT_LEAVE 2 -#define FSCACHE_POINT_DEBUG 4 - -#ifndef FSCACHE_DEBUG_LEVEL -#define FSCACHE_DEBUG_LEVEL CACHE -#endif - -/* - * assertions - */ -#if 1 /* defined(__KDEBUGALL) */ - -#define ASSERT(X) \ -do { \ - if (unlikely(!(X))) { \ - pr_err("\n"); \ - pr_err("Assertion failed\n"); \ - BUG(); \ - } \ -} while (0) - -#define ASSERTCMP(X, OP, Y) \ -do { \ - if (unlikely(!((X) OP (Y)))) { \ - pr_err("\n"); \ - pr_err("Assertion failed\n"); \ - pr_err("%lx " #OP " %lx is false\n", \ - (unsigned long)(X), (unsigned long)(Y)); \ - BUG(); \ - } \ -} while (0) - -#define ASSERTIF(C, X) \ -do { \ - if (unlikely((C) && !(X))) { \ - pr_err("\n"); \ - pr_err("Assertion failed\n"); \ - BUG(); \ - } \ -} while (0) - -#define ASSERTIFCMP(C, X, OP, Y) \ -do { \ - if (unlikely((C) && !((X) OP (Y)))) { \ - pr_err("\n"); \ - pr_err("Assertion failed\n"); \ - pr_err("%lx " #OP " %lx is false\n", \ - (unsigned long)(X), (unsigned long)(Y)); \ - BUG(); \ - } \ -} while (0) - -#else - -#define ASSERT(X) do {} while (0) -#define ASSERTCMP(X, OP, Y) do {} while (0) -#define ASSERTIF(C, X) do {} while (0) -#define ASSERTIFCMP(C, X, OP, Y) do {} while (0) - -#endif /* assert or not */ diff --git a/fs/netfs/fscache_main.c b/fs/netfs/fscache_main.c index dad85fd84f6f..00600a4d9ce5 100644 --- a/fs/netfs/fscache_main.c +++ b/fs/netfs/fscache_main.c @@ -8,18 +8,9 @@ #define FSCACHE_DEBUG_LEVEL CACHE #include #include -#define CREATE_TRACE_POINTS #include "internal.h" - -MODULE_DESCRIPTION("FS Cache Manager"); -MODULE_AUTHOR("Red Hat, Inc."); -MODULE_LICENSE("GPL"); - -unsigned fscache_debug; -module_param_named(debug, fscache_debug, uint, - S_IWUSR | S_IRUGO); -MODULE_PARM_DESC(fscache_debug, - "FS-Cache debugging mask"); +#define CREATE_TRACE_POINTS +#include EXPORT_TRACEPOINT_SYMBOL(fscache_access_cache); EXPORT_TRACEPOINT_SYMBOL(fscache_access_volume); @@ -92,7 +83,7 @@ static int __init fscache_init(void) goto error_cookie_jar; } - pr_notice("Loaded\n"); + pr_notice("FS-Cache loaded\n"); return 0; error_cookie_jar: @@ -115,7 +106,7 @@ static void __exit fscache_exit(void) kmem_cache_destroy(fscache_cookie_jar); fscache_proc_cleanup(); destroy_workqueue(fscache_wq); - pr_notice("Unloaded\n"); + pr_notice("FS-Cache unloaded\n"); } module_exit(fscache_exit); diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index e96432499eb2..43769ac606e8 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -9,8 +9,9 @@ #include #include #include +#include #include -#include "fscache_internal.h" +#include #ifdef pr_fmt #undef pr_fmt @@ -106,11 +107,143 @@ static inline bool netfs_is_cache_enabled(struct netfs_inode *ctx) #endif } +/* + * fscache-cache.c + */ +#ifdef CONFIG_PROC_FS +extern const struct seq_operations fscache_caches_seq_ops; +#endif +bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why); +void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why); +struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache); +void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where); + +static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache) +{ + return smp_load_acquire(&cache->state); +} + +static inline bool fscache_cache_is_live(const struct fscache_cache *cache) +{ + return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE; +} + +static inline void fscache_set_cache_state(struct fscache_cache *cache, + enum fscache_cache_state new_state) +{ + smp_store_release(&cache->state, new_state); + +} + +static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache, + enum fscache_cache_state old_state, + enum fscache_cache_state new_state) +{ + return try_cmpxchg_release(&cache->state, &old_state, new_state); +} + +/* + * fscache-cookie.c + */ +extern struct kmem_cache *fscache_cookie_jar; +#ifdef CONFIG_PROC_FS +extern const struct seq_operations fscache_cookies_seq_ops; +#endif +extern struct timer_list fscache_cookie_lru_timer; + +extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix); +extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie, + enum fscache_access_trace why); + +static inline void fscache_see_cookie(struct fscache_cookie *cookie, + enum fscache_cookie_trace where) +{ + trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref), + where); +} + +/* + * fscache-main.c + */ +extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len); + +/* + * fscache-proc.c + */ +#ifdef CONFIG_PROC_FS +extern int __init fscache_proc_init(void); +extern void fscache_proc_cleanup(void); +#else +#define fscache_proc_init() (0) +#define fscache_proc_cleanup() do {} while (0) +#endif + +/* + * fscache-stats.c + */ +#ifdef CONFIG_FSCACHE_STATS +extern atomic_t fscache_n_volumes; +extern atomic_t fscache_n_volumes_collision; +extern atomic_t fscache_n_volumes_nomem; +extern atomic_t fscache_n_cookies; +extern atomic_t fscache_n_cookies_lru; +extern atomic_t fscache_n_cookies_lru_expired; +extern atomic_t fscache_n_cookies_lru_removed; +extern atomic_t fscache_n_cookies_lru_dropped; + +extern atomic_t fscache_n_acquires; +extern atomic_t fscache_n_acquires_ok; +extern atomic_t fscache_n_acquires_oom; + +extern atomic_t fscache_n_invalidates; + +extern atomic_t fscache_n_relinquishes; +extern atomic_t fscache_n_relinquishes_retire; +extern atomic_t fscache_n_relinquishes_dropped; + +extern atomic_t fscache_n_resizes; +extern atomic_t fscache_n_resizes_null; + +static inline void fscache_stat(atomic_t *stat) +{ + atomic_inc(stat); +} + +static inline void fscache_stat_d(atomic_t *stat) +{ + atomic_dec(stat); +} + +#define __fscache_stat(stat) (stat) + +int fscache_stats_show(struct seq_file *m, void *v); +#else + +#define __fscache_stat(stat) (NULL) +#define fscache_stat(stat) do {} while (0) +#define fscache_stat_d(stat) do {} while (0) +#endif + +/* + * fscache-volume.c + */ +#ifdef CONFIG_PROC_FS +extern const struct seq_operations fscache_volumes_seq_ops; +#endif + +struct fscache_volume *fscache_get_volume(struct fscache_volume *volume, + enum fscache_volume_trace where); +void fscache_put_volume(struct fscache_volume *volume, + enum fscache_volume_trace where); +bool fscache_begin_volume_access(struct fscache_volume *volume, + struct fscache_cookie *cookie, + enum fscache_access_trace why); +void fscache_create_volume(struct fscache_volume *volume, bool wait); + /*****************************************************************************/ /* * debug tracing */ -#if 0 #define dbgprintk(FMT, ...) \ printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) @@ -147,4 +280,57 @@ do { \ #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) #endif -#endif + +/* + * assertions + */ +#if 1 /* defined(__KDEBUGALL) */ + +#define ASSERT(X) \ +do { \ + if (unlikely(!(X))) { \ + pr_err("\n"); \ + pr_err("Assertion failed\n"); \ + BUG(); \ + } \ +} while (0) + +#define ASSERTCMP(X, OP, Y) \ +do { \ + if (unlikely(!((X) OP (Y)))) { \ + pr_err("\n"); \ + pr_err("Assertion failed\n"); \ + pr_err("%lx " #OP " %lx is false\n", \ + (unsigned long)(X), (unsigned long)(Y)); \ + BUG(); \ + } \ +} while (0) + +#define ASSERTIF(C, X) \ +do { \ + if (unlikely((C) && !(X))) { \ + pr_err("\n"); \ + pr_err("Assertion failed\n"); \ + BUG(); \ + } \ +} while (0) + +#define ASSERTIFCMP(C, X, OP, Y) \ +do { \ + if (unlikely((C) && !((X) OP (Y)))) { \ + pr_err("\n"); \ + pr_err("Assertion failed\n"); \ + pr_err("%lx " #OP " %lx is false\n", \ + (unsigned long)(X), (unsigned long)(Y)); \ + BUG(); \ + } \ +} while (0) + +#else + +#define ASSERT(X) do {} while (0) +#define ASSERTCMP(X, OP, Y) do {} while (0) +#define ASSERTIF(C, X) do {} while (0) +#define ASSERTIFCMP(C, X, OP, Y) do {} while (0) + +#endif /* assert or not */ diff --git a/fs/netfs/main.c b/fs/netfs/main.c index 237c54a01d97..1ba8091fcf3e 100644 --- a/fs/netfs/main.c +++ b/fs/netfs/main.c @@ -8,8 +8,8 @@ #include #include #include "internal.h" -//#define CREATE_TRACE_POINTS -//#include +#define CREATE_TRACE_POINTS +#include MODULE_DESCRIPTION("Network fs support"); MODULE_AUTHOR("Red Hat, Inc."); diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig index 01ac733a6320..f7e32d76e34d 100644 --- a/fs/nfs/Kconfig +++ b/fs/nfs/Kconfig @@ -169,8 +169,8 @@ config ROOT_NFS config NFS_FSCACHE bool "Provide NFS client caching support" - depends on NFS_FS=m && FSCACHE || NFS_FS=y && FSCACHE=y - select NETFS_SUPPORT + depends on NFS_FS=m && NETFS_SUPPORT || NFS_FS=y && NETFS_SUPPORT=y + select FSCACHE help Say Y here if you want NFS data to be cached locally on disc through the general filesystem cache manager