diff options
author | NeilBrown <neilb@suse.de> | 2006-03-27 11:14:59 +0200 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-27 18:44:41 +0200 |
commit | efc36aa5608f5717338747e152c23f2cfdb14697 (patch) | |
tree | ab444f6e6c88ed07a8d5a034777c10de50e663fd /net/sunrpc/svcauth.c | |
parent | [PATCH] autofs4: atomic var underflow (diff) | |
download | linux-efc36aa5608f5717338747e152c23f2cfdb14697.tar.xz linux-efc36aa5608f5717338747e152c23f2cfdb14697.zip |
[PATCH] knfsd: Change the store of auth_domains to not be a 'cache'
The 'auth_domain's are simply handles on internal data structures. They do
not cache information from user-space, and forcing them into the mold of a
'cache' misrepresents their true nature and causes confusion.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'net/sunrpc/svcauth.c')
-rw-r--r-- | net/sunrpc/svcauth.c | 122 |
1 files changed, 33 insertions, 89 deletions
diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c index dda4f0c63511..5b28c6176806 100644 --- a/net/sunrpc/svcauth.c +++ b/net/sunrpc/svcauth.c @@ -106,112 +106,56 @@ svc_auth_unregister(rpc_authflavor_t flavor) EXPORT_SYMBOL(svc_auth_unregister); /************************************************** - * cache for domain name to auth_domain - * Entries are only added by flavours which will normally - * have a structure that 'inherits' from auth_domain. - * e.g. when an IP -> domainname is given to auth_unix, - * and the domain name doesn't exist, it will create a - * auth_unix_domain and add it to this hash table. - * If it finds the name does exist, but isn't AUTH_UNIX, - * it will complain. + * 'auth_domains' are stored in a hash table indexed by name. + * When the last reference to an 'auth_domain' is dropped, + * the object is unhashed and freed. + * If auth_domain_lookup fails to find an entry, it will return + * it's second argument 'new'. If this is non-null, it will + * have been atomically linked into the table. */ -/* - * Auth auth_domain cache is somewhat different to other caches, - * largely because the entries are possibly of different types: - * each auth flavour has it's own type. - * One consequence of this that DefineCacheLookup cannot - * allocate a new structure as it cannot know the size. - * Notice that the "INIT" code fragment is quite different - * from other caches. When auth_domain_lookup might be - * creating a new domain, the new domain is passed in - * complete and it is used as-is rather than being copied into - * another structure. - */ #define DN_HASHBITS 6 #define DN_HASHMAX (1<<DN_HASHBITS) #define DN_HASHMASK (DN_HASHMAX-1) -static struct cache_head *auth_domain_table[DN_HASHMAX]; - -static void auth_domain_drop(struct cache_head *item, struct cache_detail *cd) -{ - struct auth_domain *dom = container_of(item, struct auth_domain, h); - if (cache_put(item,cd)) - authtab[dom->flavour]->domain_release(dom); -} - - -struct cache_detail auth_domain_cache = { - .owner = THIS_MODULE, - .hash_size = DN_HASHMAX, - .hash_table = auth_domain_table, - .name = "auth.domain", - .cache_put = auth_domain_drop, -}; +static struct hlist_head auth_domain_table[DN_HASHMAX]; +static spinlock_t auth_domain_lock = SPIN_LOCK_UNLOCKED; void auth_domain_put(struct auth_domain *dom) { - auth_domain_drop(&dom->h, &auth_domain_cache); -} - -static inline int auth_domain_hash(struct auth_domain *item) -{ - return hash_str(item->name, DN_HASHBITS); -} -static inline int auth_domain_match(struct auth_domain *tmp, struct auth_domain *item) -{ - return strcmp(tmp->name, item->name) == 0; + if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) { + hlist_del(&dom->hash); + dom->flavour->domain_release(dom); + } } struct auth_domain * -auth_domain_lookup(struct auth_domain *item, int set) +auth_domain_lookup(char *name, struct auth_domain *new) { - struct auth_domain *tmp = NULL; - struct cache_head **hp, **head; - head = &auth_domain_cache.hash_table[auth_domain_hash(item)]; - - if (set) - write_lock(&auth_domain_cache.hash_lock); - else - read_lock(&auth_domain_cache.hash_lock); - for (hp=head; *hp != NULL; hp = &tmp->h.next) { - tmp = container_of(*hp, struct auth_domain, h); - if (!auth_domain_match(tmp, item)) - continue; - if (!set) { - cache_get(&tmp->h); - goto out_noset; + struct auth_domain *hp; + struct hlist_head *head; + struct hlist_node *np; + + head = &auth_domain_table[hash_str(name, DN_HASHBITS)]; + + spin_lock(&auth_domain_lock); + + hlist_for_each_entry(hp, np, head, hash) { + if (strcmp(hp->name, name)==0) { + kref_get(&hp->ref); + spin_unlock(&auth_domain_lock); + return hp; } - *hp = tmp->h.next; - tmp->h.next = NULL; - auth_domain_drop(&tmp->h, &auth_domain_cache); - goto out_set; } - /* Didn't find anything */ - if (!set) - goto out_nada; - auth_domain_cache.entries++; -out_set: - item->h.next = *head; - *head = &item->h; - cache_get(&item->h); - write_unlock(&auth_domain_cache.hash_lock); - cache_fresh(&auth_domain_cache, &item->h, item->h.expiry_time); - cache_get(&item->h); - return item; -out_nada: - tmp = NULL; -out_noset: - read_unlock(&auth_domain_cache.hash_lock); - return tmp; + if (new) { + hlist_add_head(&new->hash, head); + kref_get(&new->ref); + } + spin_unlock(&auth_domain_lock); + return new; } struct auth_domain *auth_domain_find(char *name) { - struct auth_domain *rv, ad; - - ad.name = name; - rv = auth_domain_lookup(&ad, 0); - return rv; + return auth_domain_lookup(name, NULL); } |