diff options
author | David Howells <dhowells@redhat.com> | 2009-04-03 16:42:38 +0100 |
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committer | David Howells <dhowells@redhat.com> | 2009-04-03 16:42:38 +0100 |
commit | 955d00917f0c094e0f2fb88df967e980ab66b8ca (patch) | |
tree | c6109684239fd45462e494fb4f26aa8e2e651922 /fs | |
parent | 4c515dd47ab41be3f89e757d441661795470b376 (diff) | |
download | op-kernel-dev-955d00917f0c094e0f2fb88df967e980ab66b8ca.zip op-kernel-dev-955d00917f0c094e0f2fb88df967e980ab66b8ca.tar.gz |
FS-Cache: Provide a slab for cookie allocation
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 <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/fscache/Makefile | 1 | ||||
-rw-r--r-- | fs/fscache/cookie.c | 56 | ||||
-rw-r--r-- | fs/fscache/internal.h | 8 | ||||
-rw-r--r-- | fs/fscache/main.c | 15 |
4 files changed, 80 insertions, 0 deletions
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 <linux/module.h> +#include <linux/slab.h> +#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"); |