diff options
| -rw-r--r-- | drivers/block/nbd.c | 60 | ||||
| -rw-r--r-- | include/uapi/linux/nbd-netlink.h | 1 |
2 files changed, 60 insertions, 1 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 614d82e7fae4..b7d663736d35 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -79,6 +79,7 @@ struct link_dead_args { #define NBD_RT_HAS_CONFIG_REF 4 #define NBD_RT_BOUND 5 #define NBD_RT_DISCONNECT_ON_CLOSE 6 +#define NBD_RT_HAS_BACKEND_FILE 7 #define NBD_DESTROY_ON_DISCONNECT 0 #define NBD_DISCONNECT_REQUESTED 1 @@ -119,6 +120,8 @@ struct nbd_device { struct completion *destroy_complete; unsigned long flags; + + char *backend; }; #define NBD_CMD_REQUEUED 1 @@ -216,6 +219,20 @@ static const struct device_attribute pid_attr = { .show = pid_show, }; +static ssize_t backend_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct gendisk *disk = dev_to_disk(dev); + struct nbd_device *nbd = (struct nbd_device *)disk->private_data; + + return sprintf(buf, "%s\n", nbd->backend ?: ""); +} + +static const struct device_attribute backend_attr = { + .attr = { .name = "backend", .mode = 0444}, + .show = backend_show, +}; + static void nbd_dev_remove(struct nbd_device *nbd) { struct gendisk *disk = nbd->disk; @@ -1211,6 +1228,12 @@ static void nbd_config_put(struct nbd_device *nbd) &config->runtime_flags)) device_remove_file(disk_to_dev(nbd->disk), &pid_attr); nbd->task_recv = NULL; + if (test_and_clear_bit(NBD_RT_HAS_BACKEND_FILE, + &config->runtime_flags)) { + device_remove_file(disk_to_dev(nbd->disk), &backend_attr); + kfree(nbd->backend); + nbd->backend = NULL; + } nbd_clear_sock(nbd); if (config->num_connections) { int i; @@ -1270,7 +1293,7 @@ static int nbd_start_device(struct nbd_device *nbd) error = device_create_file(disk_to_dev(nbd->disk), &pid_attr); if (error) { - dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); + dev_err(disk_to_dev(nbd->disk), "device_create_file failed for pid!\n"); return error; } set_bit(NBD_RT_HAS_PID_FILE, &config->runtime_flags); @@ -1657,6 +1680,7 @@ static int nbd_dev_add(int index) BLK_MQ_F_BLOCKING; nbd->tag_set.driver_data = nbd; nbd->destroy_complete = NULL; + nbd->backend = NULL; err = blk_mq_alloc_tag_set(&nbd->tag_set); if (err) @@ -1743,6 +1767,7 @@ static const struct nla_policy nbd_attr_policy[NBD_ATTR_MAX + 1] = { [NBD_ATTR_SOCKETS] = { .type = NLA_NESTED}, [NBD_ATTR_DEAD_CONN_TIMEOUT] = { .type = NLA_U64 }, [NBD_ATTR_DEVICE_LIST] = { .type = NLA_NESTED}, + [NBD_ATTR_BACKEND_IDENTIFIER] = { .type = NLA_STRING}, }; static const struct nla_policy nbd_sock_policy[NBD_SOCK_MAX + 1] = { @@ -1945,6 +1970,23 @@ again: } } ret = nbd_start_device(nbd); + if (ret) + goto out; + if (info->attrs[NBD_ATTR_BACKEND_IDENTIFIER]) { + nbd->backend = nla_strdup(info->attrs[NBD_ATTR_BACKEND_IDENTIFIER], + GFP_KERNEL); + if (!nbd->backend) { + ret = -ENOMEM; + goto out; + } + } + ret = device_create_file(disk_to_dev(nbd->disk), &backend_attr); + if (ret) { + dev_err(disk_to_dev(nbd->disk), + "device_create_file failed for backend!\n"); + goto out; + } + set_bit(NBD_RT_HAS_BACKEND_FILE, &config->runtime_flags); out: mutex_unlock(&nbd->config_lock); if (!ret) { @@ -2037,6 +2079,22 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info) index); return -EINVAL; } + if (nbd->backend) { + if (info->attrs[NBD_ATTR_BACKEND_IDENTIFIER]) { + if (nla_strcmp(info->attrs[NBD_ATTR_BACKEND_IDENTIFIER], + nbd->backend)) { + mutex_unlock(&nbd_index_mutex); + dev_err(nbd_to_dev(nbd), + "backend image doesn't match with %s\n", + nbd->backend); + return -EINVAL; + } + } else { + mutex_unlock(&nbd_index_mutex); + dev_err(nbd_to_dev(nbd), "must specify backend\n"); + return -EINVAL; + } + } if (!refcount_inc_not_zero(&nbd->refs)) { mutex_unlock(&nbd_index_mutex); printk(KERN_ERR "nbd: device at index %d is going down\n", diff --git a/include/uapi/linux/nbd-netlink.h b/include/uapi/linux/nbd-netlink.h index c5d0ef7aa7d5..2d0b90964227 100644 --- a/include/uapi/linux/nbd-netlink.h +++ b/include/uapi/linux/nbd-netlink.h @@ -35,6 +35,7 @@ enum { NBD_ATTR_SOCKETS, NBD_ATTR_DEAD_CONN_TIMEOUT, NBD_ATTR_DEVICE_LIST, + NBD_ATTR_BACKEND_IDENTIFIER, __NBD_ATTR_MAX, }; #define NBD_ATTR_MAX (__NBD_ATTR_MAX - 1) |