NFS: Fix an allocation-under-spinlock bug
sunrpc_cache_update() will always call detail->update() from inside the
detail->hash_lock, so it cannot allocate memory.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
diff --git a/fs/nfs/dns_resolve.c b/fs/nfs/dns_resolve.c
index 95e1ca7..3f0cd4d 100644
--- a/fs/nfs/dns_resolve.c
+++ b/fs/nfs/dns_resolve.c
@@ -36,6 +36,19 @@
};
+static void nfs_dns_ent_update(struct cache_head *cnew,
+ struct cache_head *ckey)
+{
+ struct nfs_dns_ent *new;
+ struct nfs_dns_ent *key;
+
+ new = container_of(cnew, struct nfs_dns_ent, h);
+ key = container_of(ckey, struct nfs_dns_ent, h);
+
+ memcpy(&new->addr, &key->addr, key->addrlen);
+ new->addrlen = key->addrlen;
+}
+
static void nfs_dns_ent_init(struct cache_head *cnew,
struct cache_head *ckey)
{
@@ -49,8 +62,7 @@
new->hostname = kstrndup(key->hostname, key->namelen, GFP_KERNEL);
if (new->hostname) {
new->namelen = key->namelen;
- memcpy(&new->addr, &key->addr, key->addrlen);
- new->addrlen = key->addrlen;
+ nfs_dns_ent_update(cnew, ckey);
} else {
new->namelen = 0;
new->addrlen = 0;
@@ -234,7 +246,7 @@
.cache_show = nfs_dns_show,
.match = nfs_dns_match,
.init = nfs_dns_ent_init,
- .update = nfs_dns_ent_init,
+ .update = nfs_dns_ent_update,
.alloc = nfs_dns_ent_alloc,
};