[PATCH v2 09/12] nfs: per-rpc_pipefs dns cache

Kirill A. Shutemov
2010-12-29T13:15:35Z

Lazy initialization of dns cache: on first call nfs_dns_resolve_name().
Every rpc_pipefs has separate dns cache now.

Signed-off-by: Kirill A. Shutemov <kas@openvz.org>
---
fs/nfs/cache_lib.c | 17 ++-----
fs/nfs/cache_lib.h | 3 +-
fs/nfs/dns_resolve.c | 128 ++++++++++++++++++++++++++++++++++++++----------
fs/nfs/dns_resolve.h | 8 +---
fs/nfs/inode.c | 8 +---
fs/nfs/nfs4namespace.c | 4 +-
6 files changed, 113 insertions(+), 55 deletions(-)

diff --git a/fs/nfs/cache_lib.c b/fs/nfs/cache_lib.c
index 0944d4e..9b99d9e 100644
--- a/fs/nfs/cache_lib.c
+++ b/fs/nfs/cache_lib.c
@@ -12,7 +12,6 @@
#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/sunrpc/cache.h>
-#include <linux/sunrpc/rpc_pipe_fs.h>

#include "cache_lib.h"

@@ -111,25 +110,17 @@ int nfs_cache_wait_for_upcall(struct nfs_cache_defer_req *dreq)
return 0;
}

-int nfs_cache_register(struct cache_detail *cd)
+int nfs_cache_register(struct cache_detail *cd, struct vfsmount *rpcmount)
{
struct nameidata nd;
- struct vfsmount *mnt;
int ret;

- mnt = mntget(init_rpc_pipefs);
- if (IS_ERR(mnt))
- return PTR_ERR(mnt);
- ret = vfs_path_lookup(mnt->mnt_root, mnt, "/cache", 0, &nd);
+ ret = vfs_path_lookup(rpcmount->mnt_root, rpcmount, "/cache", 0, &nd);
if (ret)
- goto err;
- ret = sunrpc_cache_register_pipefs(mnt, nd.path.dentry,
+ return ret;
+ ret = sunrpc_cache_register_pipefs(rpcmount, nd.path.dentry,
cd->name, 0600, cd);
path_put(&nd.path);
- if (!ret)
- return ret;
-err:
- mntput(mnt);
return ret;
}

diff --git a/fs/nfs/cache_lib.h b/fs/nfs/cache_lib.h
index 76f856e..1d4a0a5 100644
--- a/fs/nfs/cache_lib.h
+++ b/fs/nfs/cache_lib.h
@@ -23,5 +23,6 @@ extern struct nfs_cache_defer_req *nfs_cache_defer_req_alloc(void);
extern void nfs_cache_defer_req_put(struct nfs_cache_defer_req *dreq);
extern int nfs_cache_wait_for_upcall(struct nfs_cache_defer_req *dreq);

-extern int nfs_cache_register(struct cache_detail *cd);
+extern int nfs_cache_register(struct cache_detail *cd,
+ struct vfsmount *rpcmount);
extern void nfs_cache_unregister(struct cache_detail *cd);
diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c
index a6e711a..4b35323 100644
--- a/fs/nfs/dns_resolve.c
+++ b/fs/nfs/dns_resolve.c
@@ -12,7 +12,7 @@
#include <linux/dns_resolver.h>

ssize_t nfs_dns_resolve_name(char *name, size_t namelen,
- struct sockaddr *sa, size_t salen)
+ struct sockaddr *sa, size_t salen, struct vfsmount *rpcmount)
{
ssize_t ret;
char *ip_addr = NULL;
@@ -37,6 +37,7 @@ ssize_t nfs_dns_resolve_name(char *name, size_t namelen,
#include <linux/socket.h>
#include <linux/seq_file.h>
#include <linux/inet.h>
+#include <linux/mount.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/cache.h>
#include <linux/sunrpc/svcauth.h>
@@ -47,7 +48,13 @@ ssize_t nfs_dns_resolve_name(char *name, size_t namelen,
#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];
+static DEFINE_SPINLOCK(nfs_dns_resolve_lock);
+static LIST_HEAD(nfs_dns_resolve_list);
+
+struct nfs_dns_resolve_list {
+ struct list_head list;
+ struct cache_detail *cd;
+};

struct nfs_dns_ent {
struct cache_head h;
@@ -259,21 +266,6 @@ out:
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,
@@ -336,37 +328,121 @@ out:
return ret;
}

+static struct cache_detail *nfs_alloc_dns_resolve(void)
+{
+ struct cache_detail *dns_resolve;
+ struct cache_head **hash_table;
+
+ dns_resolve = kmalloc(sizeof(*dns_resolve), GFP_KERNEL);
+ if (!dns_resolve)
+ return NULL;
+
+ hash_table = kmalloc(sizeof(*hash_table) * NFS_DNS_HASHTBL_SIZE,
+ GFP_KERNEL);
+ if (!hash_table) {
+ kfree(dns_resolve);
+ return NULL;
+ }
+
+ dns_resolve->owner = THIS_MODULE;
+ dns_resolve->hash_size = NFS_DNS_HASHTBL_SIZE;
+ dns_resolve->hash_table = hash_table;
+ dns_resolve->name = "dns_resolve";
+ dns_resolve->cache_put = nfs_dns_ent_put;
+ dns_resolve->cache_upcall = nfs_dns_upcall;
+ dns_resolve->cache_parse = nfs_dns_parse;
+ dns_resolve->cache_show = nfs_dns_show;
+ dns_resolve->match = nfs_dns_match;
+ dns_resolve->init = nfs_dns_ent_init;
+ dns_resolve->update = nfs_dns_ent_update;
+ dns_resolve->alloc = nfs_dns_ent_alloc;
+
+ return dns_resolve;
+}
+
+static void nfs_free_dns_resolve(struct cache_detail *dns_resolve)
+{
+ kfree(dns_resolve->hash_table);
+ kfree(dns_resolve);
+}
+
+static struct cache_detail *nfs_get_dns_resolve(struct vfsmount *rpcmount)
+{
+ struct nfs_dns_resolve_list *dns_resolve;
+ int error = 0;
+
+ spin_lock(&nfs_dns_resolve_lock);
+ list_for_each_entry(dns_resolve, &nfs_dns_resolve_list, list) {
+ if (dns_resolve->cd->u.pipefs.mnt->mnt_sb != rpcmount->mnt_sb)
+ continue;
+
+ spin_unlock(&nfs_dns_resolve_lock);
+ return dns_resolve->cd;
+ }
+
+ dns_resolve = kmalloc(sizeof(*dns_resolve), GFP_KERNEL);
+ if (dns_resolve)
+ dns_resolve->cd = nfs_alloc_dns_resolve();
+ if (!dns_resolve || !dns_resolve->cd) {
+ error = -ENOMEM;
+ goto err;
+ }
+
+ error = nfs_cache_register(dns_resolve->cd, rpcmount);
+ if (error)
+ goto err;
+
+ INIT_LIST_HEAD(&dns_resolve->list);
+ list_add(&dns_resolve->list, &nfs_dns_resolve_list);
+ spin_unlock(&nfs_dns_resolve_lock);
+
+ return dns_resolve->cd;
+err:
+ spin_unlock(&nfs_dns_resolve_lock);
+ if (dns_resolve)
+ kfree(dns_resolve->cd);
+ kfree(dns_resolve);
+ return dns_resolve->cd;
+}
+
ssize_t nfs_dns_resolve_name(char *name, size_t namelen,
- struct sockaddr *sa, size_t salen)
+ struct sockaddr *sa, size_t salen, struct vfsmount *rpcmount)
{
struct nfs_dns_ent key = {
.hostname = name,
.namelen = namelen,
};
+ struct cache_detail *dns_resolve;
struct nfs_dns_ent *item = NULL;
ssize_t ret;

- ret = do_cache_lookup_wait(&nfs_dns_resolve, &key, &item);
+ dns_resolve = nfs_get_dns_resolve(rpcmount);
+ ret = do_cache_lookup_wait(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, dns_resolve);
} else if (ret == -ENOENT)
ret = -ESRCH;
return ret;
}

-int nfs_dns_resolver_init(void)
-{
- return nfs_cache_register(&nfs_dns_resolve);
-}
-
void nfs_dns_resolver_destroy(void)
{
- nfs_cache_unregister(&nfs_dns_resolve);
+ struct nfs_dns_resolve_list *dns_resolve, *tmp;
+
+ spin_lock(&nfs_dns_resolve_lock);
+ list_for_each_entry_safe(dns_resolve, tmp, &nfs_dns_resolve_list,
+ list) {
+ nfs_cache_unregister(dns_resolve->cd);
+ nfs_free_dns_resolve(dns_resolve->cd);
+ list_del(&dns_resolve->list);
+ kfree(dns_resolve);
+ }
+ spin_unlock(&nfs_dns_resolve_lock);
}

#endif
diff --git a/fs/nfs/dns_resolve.h b/fs/nfs/dns_resolve.h
index 199bb55..a9ae700 100644
--- a/fs/nfs/dns_resolve.h
+++ b/fs/nfs/dns_resolve.h
@@ -8,19 +8,13 @@

#ifdef CONFIG_NFS_USE_KERNEL_DNS
-static inline int nfs_dns_resolver_init(void)
-{
- return 0;
-}
-
static inline void nfs_dns_resolver_destroy(void)
{}
#else
-extern int nfs_dns_resolver_init(void);
extern void nfs_dns_resolver_destroy(void);
#endif

extern ssize_t nfs_dns_resolve_name(char *name, size_t namelen,
- struct sockaddr *sa, size_t salen);
+ struct sockaddr *sa, size_t salen, struct vfsmount *rpcmount);

#endif
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e67e31c..9fed17c 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1528,10 +1528,6 @@ static int __init init_nfs_fs(void)

err = nfs_idmap_init();
if (err < 0)
- goto out9;
-
- err = nfs_dns_resolver_init();
- if (err < 0)
goto out8;

err = nfs_fscache_register();
@@ -1592,10 +1588,8 @@ out5:
out6:
nfs_fscache_unregister();
out7:
- nfs_dns_resolver_destroy();
-out8:
nfs_idmap_quit();
-out9:
+out8:
return err;
}

diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 3c2a172..7a61fdb 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -14,6 +14,7 @@
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/vfs.h>
#include <linux/inet.h>
#include "internal.h"
@@ -104,7 +105,8 @@ static size_t nfs_parse_server_name(char *string, size_t len,

ret = rpc_pton(string, len, sa, salen);
if (ret == 0) {
- ret = nfs_dns_resolve_name(string, len, sa, salen);
+ ret = nfs_dns_resolve_name(string, len, sa, salen,
+ init_rpc_pipefs);
if (ret < 0)
ret = 0;
}
--
1.7.3.4