NFS: DNS resolver cache per network namespace context introduced
This patch implements DNS resolver cache creation and registration for each
alive network namespace context.
This was done by registering NFS per-net operations, responsible for DNS cache
allocation/register and unregister/destructioning instead of initialization and
destruction of static "nfs_dns_resolve" cache detail (this one was removed).
Pointer to network dns resolver cache is stored in new per-net "nfs_net"
structure.
This patch also changes nfs_dns_resolve_name() function prototype (and it's
calls) by adding network pointer parameter, which is used to get proper DNS
resolver cache pointer for do_cache_lookup_wait() call.
Note: empty nfs_dns_resolver_init() and nfs_dns_resolver_destroy() functions
will be used in next patch in the series.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c
index 3cbf4b8..9aea78a 100644
--- a/fs/nfs/dns_resolve.c
+++ b/fs/nfs/dns_resolve.c
@@ -11,7 +11,7 @@
#include <linux/sunrpc/clnt.h>
#include <linux/dns_resolver.h>
-ssize_t nfs_dns_resolve_name(char *name, size_t namelen,
+ssize_t nfs_dns_resolve_name(struct net *net, char *name, size_t namelen,
struct sockaddr *sa, size_t salen)
{
ssize_t ret;
@@ -43,12 +43,11 @@
#include "dns_resolve.h"
#include "cache_lib.h"
+#include "netns.h"
#define NFS_DNS_HASHBITS 4
#define NFS_DNS_HASHTBL_SIZE (1 << NFS_DNS_HASHBITS)
-static struct cache_head *nfs_dns_table[NFS_DNS_HASHTBL_SIZE];
-
struct nfs_dns_ent {
struct cache_head h;
@@ -259,21 +258,6 @@
return ret;
}
-static struct cache_detail nfs_dns_resolve = {
- .owner = THIS_MODULE,
- .hash_size = NFS_DNS_HASHTBL_SIZE,
- .hash_table = nfs_dns_table,
- .name = "dns_resolve",
- .cache_put = nfs_dns_ent_put,
- .cache_upcall = nfs_dns_upcall,
- .cache_parse = nfs_dns_parse,
- .cache_show = nfs_dns_show,
- .match = nfs_dns_match,
- .init = nfs_dns_ent_init,
- .update = nfs_dns_ent_update,
- .alloc = nfs_dns_ent_alloc,
-};
-
static int do_cache_lookup(struct cache_detail *cd,
struct nfs_dns_ent *key,
struct nfs_dns_ent **item,
@@ -336,8 +320,8 @@
return ret;
}
-ssize_t nfs_dns_resolve_name(char *name, size_t namelen,
- struct sockaddr *sa, size_t salen)
+ssize_t nfs_dns_resolve_name(struct net *net, char *name,
+ size_t namelen, struct sockaddr *sa, size_t salen)
{
struct nfs_dns_ent key = {
.hostname = name,
@@ -345,37 +329,83 @@
};
struct nfs_dns_ent *item = NULL;
ssize_t ret;
+ struct nfs_net *nn = net_generic(net, nfs_net_id);
- ret = do_cache_lookup_wait(&nfs_dns_resolve, &key, &item);
+ ret = do_cache_lookup_wait(nn->nfs_dns_resolve, &key, &item);
if (ret == 0) {
if (salen >= item->addrlen) {
memcpy(sa, &item->addr, item->addrlen);
ret = item->addrlen;
} else
ret = -EOVERFLOW;
- cache_put(&item->h, &nfs_dns_resolve);
+ cache_put(&item->h, nn->nfs_dns_resolve);
} else if (ret == -ENOENT)
ret = -ESRCH;
return ret;
}
+int nfs_dns_resolver_cache_init(struct net *net)
+{
+ int err = -ENOMEM;
+ struct nfs_net *nn = net_generic(net, nfs_net_id);
+ struct cache_detail *cd;
+ struct cache_head **tbl;
+
+ cd = kzalloc(sizeof(struct cache_detail), GFP_KERNEL);
+ if (cd == NULL)
+ goto err_cd;
+
+ tbl = kzalloc(NFS_DNS_HASHTBL_SIZE * sizeof(struct cache_head *),
+ GFP_KERNEL);
+ if (tbl == NULL)
+ goto err_tbl;
+
+ cd->owner = THIS_MODULE,
+ cd->hash_size = NFS_DNS_HASHTBL_SIZE,
+ cd->hash_table = tbl,
+ cd->name = "dns_resolve",
+ cd->cache_put = nfs_dns_ent_put,
+ cd->cache_upcall = nfs_dns_upcall,
+ cd->cache_parse = nfs_dns_parse,
+ cd->cache_show = nfs_dns_show,
+ cd->match = nfs_dns_match,
+ cd->init = nfs_dns_ent_init,
+ cd->update = nfs_dns_ent_update,
+ cd->alloc = nfs_dns_ent_alloc,
+
+ nfs_cache_init(cd);
+ err = nfs_cache_register_net(net, cd);
+ if (err)
+ goto err_reg;
+ nn->nfs_dns_resolve = cd;
+ return 0;
+
+err_reg:
+ nfs_cache_destroy(cd);
+ kfree(cd->hash_table);
+err_tbl:
+ kfree(cd);
+err_cd:
+ return err;
+}
+
+void nfs_dns_resolver_cache_destroy(struct net *net)
+{
+ struct nfs_net *nn = net_generic(net, nfs_net_id);
+ struct cache_detail *cd = nn->nfs_dns_resolve;
+
+ nfs_cache_unregister_net(net, cd);
+ nfs_cache_destroy(cd);
+ kfree(cd->hash_table);
+ kfree(cd);
+}
+
int nfs_dns_resolver_init(void)
{
- int err;
-
- nfs_cache_init(&nfs_dns_resolve);
- err = nfs_cache_register_net(&init_net, &nfs_dns_resolve);
- if (err) {
- nfs_cache_destroy(&nfs_dns_resolve);
- return err;
- }
return 0;
}
void nfs_dns_resolver_destroy(void)
{
- nfs_cache_unregister_net(&init_net, &nfs_dns_resolve);
- nfs_cache_destroy(&nfs_dns_resolve);
}
-
#endif
