Commit b7aa3d39 authored by Josef Bacik's avatar Josef Bacik Committed by Jens Axboe

nbd: add a reconfigure netlink command

We want to be able to reconnect dead connections to existing block
devices, so add a reconfigure netlink command.  We will also allow users
to change their timeout on the fly, but everything else will require a
disconnect and reconnect.  You won't be able to add more connections
either, simply replace dead connections with new more lively
connections.
Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent e46c7287
...@@ -785,6 +785,59 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, ...@@ -785,6 +785,59 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
return 0; return 0;
} }
static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg)
{
struct nbd_config *config = nbd->config;
struct socket *sock, *old;
struct recv_thread_args *args;
int i;
int err;
sock = sockfd_lookup(arg, &err);
if (!sock)
return err;
args = kzalloc(sizeof(*args), GFP_KERNEL);
if (!args) {
sockfd_put(sock);
return -ENOMEM;
}
for (i = 0; i < config->num_connections; i++) {
struct nbd_sock *nsock = config->socks[i];
if (!nsock->dead)
continue;
mutex_lock(&nsock->tx_lock);
if (!nsock->dead) {
mutex_unlock(&nsock->tx_lock);
continue;
}
sk_set_memalloc(sock->sk);
atomic_inc(&config->recv_threads);
refcount_inc(&nbd->config_refs);
old = nsock->sock;
nsock->fallback_index = -1;
nsock->sock = sock;
nsock->dead = false;
INIT_WORK(&args->work, recv_work);
args->index = i;
args->nbd = nbd;
mutex_unlock(&nsock->tx_lock);
sockfd_put(old);
/* We take the tx_mutex in an error path in the recv_work, so we
* need to queue_work outside of the tx_mutex.
*/
queue_work(recv_workqueue, &args->work);
return 0;
}
sockfd_put(sock);
kfree(args);
return -ENOSPC;
}
/* Reset all properties of an NBD device */ /* Reset all properties of an NBD device */
static void nbd_reset(struct nbd_device *nbd) static void nbd_reset(struct nbd_device *nbd)
{ {
...@@ -1528,6 +1581,89 @@ static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info) ...@@ -1528,6 +1581,89 @@ static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
return 0; return 0;
} }
static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
{
struct nbd_device *nbd = NULL;
struct nbd_config *config;
int index;
int ret = -EINVAL;
if (!netlink_capable(skb, CAP_SYS_ADMIN))
return -EPERM;
if (!info->attrs[NBD_ATTR_INDEX]) {
printk(KERN_ERR "nbd: must specify a device to reconfigure\n");
return -EINVAL;
}
index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
mutex_lock(&nbd_index_mutex);
nbd = idr_find(&nbd_index_idr, index);
mutex_unlock(&nbd_index_mutex);
if (!nbd) {
printk(KERN_ERR "nbd: couldn't find a device at index %d\n",
index);
return -EINVAL;
}
if (!refcount_inc_not_zero(&nbd->config_refs)) {
dev_err(nbd_to_dev(nbd),
"not configured, cannot reconfigure\n");
return -EINVAL;
}
mutex_lock(&nbd->config_lock);
config = nbd->config;
if (!test_bit(NBD_BOUND, &config->runtime_flags) ||
!nbd->task_recv) {
dev_err(nbd_to_dev(nbd),
"not configured, cannot reconfigure\n");
goto out;
}
if (info->attrs[NBD_ATTR_TIMEOUT]) {
u64 timeout = nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]);
nbd->tag_set.timeout = timeout * HZ;
blk_queue_rq_timeout(nbd->disk->queue, timeout * HZ);
}
if (info->attrs[NBD_ATTR_SOCKETS]) {
struct nlattr *attr;
int rem, fd;
nla_for_each_nested(attr, info->attrs[NBD_ATTR_SOCKETS],
rem) {
struct nlattr *socks[NBD_SOCK_MAX+1];
if (nla_type(attr) != NBD_SOCK_ITEM) {
printk(KERN_ERR "nbd: socks must be embedded in a SOCK_ITEM attr\n");
ret = -EINVAL;
goto out;
}
ret = nla_parse_nested(socks, NBD_SOCK_MAX, attr,
nbd_sock_policy);
if (ret != 0) {
printk(KERN_ERR "nbd: error processing sock list\n");
ret = -EINVAL;
goto out;
}
if (!socks[NBD_SOCK_FD])
continue;
fd = (int)nla_get_u32(socks[NBD_SOCK_FD]);
ret = nbd_reconnect_socket(nbd, fd);
if (ret) {
if (ret == -ENOSPC)
ret = 0;
goto out;
}
dev_info(nbd_to_dev(nbd), "reconnected socket\n");
}
}
out:
mutex_unlock(&nbd->config_lock);
nbd_config_put(nbd);
return ret;
}
static const struct genl_ops nbd_connect_genl_ops[] = { static const struct genl_ops nbd_connect_genl_ops[] = {
{ {
.cmd = NBD_CMD_CONNECT, .cmd = NBD_CMD_CONNECT,
...@@ -1539,6 +1675,11 @@ static const struct genl_ops nbd_connect_genl_ops[] = { ...@@ -1539,6 +1675,11 @@ static const struct genl_ops nbd_connect_genl_ops[] = {
.policy = nbd_attr_policy, .policy = nbd_attr_policy,
.doit = nbd_genl_disconnect, .doit = nbd_genl_disconnect,
}, },
{
.cmd = NBD_CMD_RECONFIGURE,
.policy = nbd_attr_policy,
.doit = nbd_genl_reconfigure,
},
}; };
static struct genl_family nbd_genl_family __ro_after_init = { static struct genl_family nbd_genl_family __ro_after_init = {
......
...@@ -62,6 +62,7 @@ enum { ...@@ -62,6 +62,7 @@ enum {
NBD_CMD_UNSPEC, NBD_CMD_UNSPEC,
NBD_CMD_CONNECT, NBD_CMD_CONNECT,
NBD_CMD_DISCONNECT, NBD_CMD_DISCONNECT,
NBD_CMD_RECONFIGURE,
__NBD_CMD_MAX, __NBD_CMD_MAX,
}; };
#define NBD_CMD_MAX (__NBD_CMD_MAX - 1) #define NBD_CMD_MAX (__NBD_CMD_MAX - 1)
......
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