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Registered in England and Wales under Company Registration No. 3798903 From: David Howells Subject: [PATCH 14/43] FS-Cache: Provide a slab for cookie allocation [ver #46] To: viro@ZenIV.linux.org.uk Cc: dhowells@redhat.com, nfsv4@linux-nfs.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Date: Thu, 02 Apr 2009 00:04:33 +0100 Message-ID: <20090401230433.28177.68336.stgit@warthog.procyon.org.uk> In-Reply-To: <20090401230321.28177.12010.stgit@warthog.procyon.org.uk> References: <20090401230321.28177.12010.stgit@warthog.procyon.org.uk> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4265 Lines: 158 Provide a slab from which can be allocated the FS-Cache cookies that will be presented to the netfs. Also provide a slab constructor and a function to recursively discard a cookie and its ancestor chain. Signed-off-by: David Howells Acked-by: Steve Dickson Acked-by: Trond Myklebust --- fs/fscache/Makefile | 1 + fs/fscache/cookie.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++ fs/fscache/internal.h | 8 +++++++ fs/fscache/main.c | 15 +++++++++++++ 4 files changed, 80 insertions(+), 0 deletions(-) create mode 100644 fs/fscache/cookie.c diff --git a/fs/fscache/Makefile b/fs/fscache/Makefile index 556708b..f88ac17 100644 --- a/fs/fscache/Makefile +++ b/fs/fscache/Makefile @@ -4,6 +4,7 @@ fscache-y := \ cache.o \ + cookie.o \ fsdef.o \ main.o diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c new file mode 100644 index 0000000..47fd75b --- /dev/null +++ b/fs/fscache/cookie.c @@ -0,0 +1,56 @@ +/* netfs cookie management + * + * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#define FSCACHE_DEBUG_LEVEL COOKIE +#include +#include +#include "internal.h" + +struct kmem_cache *fscache_cookie_jar; + +/* + * initialise an cookie jar slab element prior to any use + */ +void fscache_cookie_init_once(void *_cookie) +{ + struct fscache_cookie *cookie = _cookie; + + memset(cookie, 0, sizeof(*cookie)); + spin_lock_init(&cookie->lock); + INIT_HLIST_HEAD(&cookie->backing_objects); +} + +/* + * destroy a cookie + */ +void __fscache_cookie_put(struct fscache_cookie *cookie) +{ + struct fscache_cookie *parent; + + _enter("%p", cookie); + + for (;;) { + _debug("FREE COOKIE %p", cookie); + parent = cookie->parent; + BUG_ON(!hlist_empty(&cookie->backing_objects)); + kmem_cache_free(fscache_cookie_jar, cookie); + + if (!parent) + break; + + cookie = parent; + BUG_ON(atomic_read(&cookie->usage) <= 0); + if (!atomic_dec_and_test(&cookie->usage)) + break; + } + + _leave(""); +} diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h index 0a2069a..4c6ba56 100644 --- a/fs/fscache/internal.h +++ b/fs/fscache/internal.h @@ -37,6 +37,14 @@ extern struct fscache_cache *fscache_select_cache_for_object( struct fscache_cookie *); /* + * fsc-cookie.c + */ +extern struct kmem_cache *fscache_cookie_jar; + +extern void fscache_cookie_init_once(void *); +extern void __fscache_cookie_put(struct fscache_cookie *); + +/* * fsc-fsdef.c */ extern struct fscache_cookie fscache_fsdef_index; diff --git a/fs/fscache/main.c b/fs/fscache/main.c index c2f3e63..48b79d2 100644 --- a/fs/fscache/main.c +++ b/fs/fscache/main.c @@ -56,6 +56,18 @@ static int __init fscache_init(void) if (ret < 0) goto error_proc; + fscache_cookie_jar = kmem_cache_create("fscache_cookie_jar", + sizeof(struct fscache_cookie), + 0, + 0, + fscache_cookie_init_once); + if (!fscache_cookie_jar) { + printk(KERN_NOTICE + "FS-Cache: Failed to allocate a cookie jar\n"); + ret = -ENOMEM; + goto error_cookie_jar; + } + fscache_root = kobject_create_and_add("fscache", kernel_kobj); if (!fscache_root) goto error_kobj; @@ -64,6 +76,8 @@ static int __init fscache_init(void) return 0; error_kobj: + kmem_cache_destroy(fscache_cookie_jar); +error_cookie_jar: fscache_proc_cleanup(); error_proc: slow_work_unregister_user(); @@ -81,6 +95,7 @@ static void __exit fscache_exit(void) _enter(""); kobject_put(fscache_root); + kmem_cache_destroy(fscache_cookie_jar); fscache_proc_cleanup(); slow_work_unregister_user(); printk(KERN_NOTICE "FS-Cache: Unloaded\n"); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/