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
This commit is contained in:
Trond Myklebust 2010-03-02 13:06:22 -05:00
parent 9fcfe0c83c
commit ebed9203b6
1 changed files with 15 additions and 3 deletions

View File

@ -36,6 +36,19 @@ struct nfs_dns_ent {
};
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 @@ static void nfs_dns_ent_init(struct cache_head *cnew,
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 @@ static struct cache_detail nfs_dns_resolve = {
.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,
};