diff options
| -rw-r--r-- | drivers/block/nbd.c | 316 | ||||
| -rw-r--r-- | include/uapi/linux/nbd-netlink.h | 69 |
2 files changed, 359 insertions, 26 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index d5828b9dbfef..efd2eba37c69 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -40,6 +40,8 @@ #include <asm/types.h> #include <linux/nbd.h> +#include <linux/nbd-netlink.h> +#include <net/genetlink.h> static DEFINE_IDR(nbd_index_idr); static DEFINE_MUTEX(nbd_index_mutex); @@ -63,6 +65,8 @@ struct recv_thread_args { #define NBD_DISCONNECT_REQUESTED 1 #define NBD_DISCONNECTED 2 #define NBD_HAS_PID_FILE 3 +#define NBD_HAS_CONFIG_REF 4 +#define NBD_BOUND 5 struct nbd_config { u32 flags; @@ -83,6 +87,7 @@ struct nbd_config { struct nbd_device { struct blk_mq_tag_set tag_set; + int index; refcount_t config_refs; struct nbd_config *config; struct mutex config_lock; @@ -114,6 +119,7 @@ static int part_shift; static int nbd_dev_dbg_init(struct nbd_device *nbd); static void nbd_dev_dbg_close(struct nbd_device *nbd); static void nbd_config_put(struct nbd_device *nbd); +static void nbd_connect_reply(struct genl_info *info, int index); static inline struct device *nbd_to_dev(struct nbd_device *nbd) { @@ -728,7 +734,8 @@ static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx, return ret; } -static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg) +static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, + bool netlink) { struct nbd_config *config = nbd->config; struct socket *sock; @@ -740,13 +747,17 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg) if (!sock) return err; - if (!nbd->task_setup) + if (!netlink && !nbd->task_setup && + !test_bit(NBD_BOUND, &config->runtime_flags)) nbd->task_setup = current; - if (nbd->task_setup != current) { + + if (!netlink && + (nbd->task_setup != current || + test_bit(NBD_BOUND, &config->runtime_flags))) { dev_err(disk_to_dev(nbd->disk), "Device being setup by another task"); sockfd_put(sock); - return -EINVAL; + return -EBUSY; } socks = krealloc(config->socks, (config->num_connections + 1) * @@ -872,7 +883,7 @@ static void nbd_config_put(struct nbd_device *nbd) } } -static int nbd_start_device(struct nbd_device *nbd, struct block_device *bdev) +static int nbd_start_device(struct nbd_device *nbd) { struct nbd_config *config = nbd->config; int num_connections = config->num_connections; @@ -888,11 +899,8 @@ static int nbd_start_device(struct nbd_device *nbd, struct block_device *bdev) return -EINVAL; } - if (max_part) - bdev->bd_invalidated = 1; blk_mq_update_nr_hw_queues(&nbd->tag_set, config->num_connections); nbd->task_recv = current; - mutex_unlock(&nbd->config_lock); nbd_parse_flags(nbd); @@ -901,11 +909,7 @@ static int nbd_start_device(struct nbd_device *nbd, struct block_device *bdev) dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); return error; } - set_bit(NBD_HAS_PID_FILE, &config->runtime_flags); - if (max_part) - bdev->bd_invalidated = 1; - bd_set_size(bdev, config->bytesize); nbd_dev_dbg_init(nbd); for (i = 0; i < num_connections; i++) { @@ -924,18 +928,34 @@ static int nbd_start_device(struct nbd_device *nbd, struct block_device *bdev) args->index = i; queue_work(recv_workqueue, &args->work); } - error = wait_event_interruptible(config->recv_wq, + return error; +} + +static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *bdev) +{ + struct nbd_config *config = nbd->config; + int ret; + + ret = nbd_start_device(nbd); + if (ret) + return ret; + + bd_set_size(bdev, config->bytesize); + if (max_part) + bdev->bd_invalidated = 1; + mutex_unlock(&nbd->config_lock); + ret = wait_event_interruptible(config->recv_wq, atomic_read(&config->recv_threads) == 0); - if (error) + if (ret) sock_shutdown(nbd); mutex_lock(&nbd->config_lock); - + bd_set_size(bdev, 0); /* user requested, ignore socket errors */ if (test_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags)) - error = 0; + ret = 0; if (test_bit(NBD_TIMEDOUT, &config->runtime_flags)) - error = -ETIMEDOUT; - return error; + ret = -ETIMEDOUT; + return ret; } static void nbd_clear_sock_ioctl(struct nbd_device *nbd, @@ -944,6 +964,9 @@ static void nbd_clear_sock_ioctl(struct nbd_device *nbd, nbd_clear_sock(nbd); kill_bdev(bdev); nbd_bdev_reset(bdev); + if (test_and_clear_bit(NBD_HAS_CONFIG_REF, + &nbd->config->runtime_flags)) + nbd_config_put(nbd); } /* Must be called with config_lock held */ @@ -959,7 +982,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, nbd_clear_sock_ioctl(nbd, bdev); return 0; case NBD_SET_SOCK: - return nbd_add_socket(nbd, arg); + return nbd_add_socket(nbd, arg, false); case NBD_SET_BLKSIZE: nbd_size_set(nbd, arg, div_s64(config->bytesize, arg)); @@ -982,7 +1005,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, config->flags = arg; return 0; case NBD_DO_IT: - return nbd_start_device(nbd, bdev); + return nbd_start_device_ioctl(nbd, bdev); case NBD_CLEAR_QUE: /* * This is for compatibility only. The queue is always cleared @@ -1003,13 +1026,22 @@ static int nbd_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { struct nbd_device *nbd = bdev->bd_disk->private_data; - int error; + struct nbd_config *config = nbd->config; + int error = -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EPERM; mutex_lock(&nbd->config_lock); - error = __nbd_ioctl(bdev, nbd, cmd, arg); + + /* Don't allow ioctl operations on a nbd device that was created with + * netlink, unless it's DISCONNECT or CLEAR_SOCK, which are fine. + */ + if (!test_bit(NBD_BOUND, &config->runtime_flags) || + (cmd == NBD_DISCONNECT || cmd == NBD_CLEAR_SOCK)) + error = __nbd_ioctl(bdev, nbd, cmd, arg); + else + dev_err(nbd_to_dev(nbd), "Cannot use ioctl interface on a netlink controlled device.\n"); mutex_unlock(&nbd->config_lock); return error; } @@ -1258,6 +1290,7 @@ static int nbd_dev_add(int index) if (err < 0) goto out_free_disk; + nbd->index = index; nbd->disk = disk; nbd->tag_set.ops = &nbd_mq_ops; nbd->tag_set.nr_hw_queues = 1; @@ -1312,10 +1345,235 @@ out: return err; } -/* - * And here should be modules and kernel interface - * (Just smiley confuses emacs :-) - */ +static int find_free_cb(int id, void *ptr, void *data) +{ + struct nbd_device *nbd = ptr; + struct nbd_device **found = data; + + if (!refcount_read(&nbd->config_refs)) { + *found = nbd; + return 1; + } + return 0; +} + +/* Netlink interface. */ +static struct nla_policy nbd_attr_policy[NBD_ATTR_MAX + 1] = { + [NBD_ATTR_INDEX] = { .type = NLA_U32 }, + [NBD_ATTR_SIZE_BYTES] = { .type = NLA_U64 }, + [NBD_ATTR_BLOCK_SIZE_BYTES] = { .type = NLA_U64 }, + [NBD_ATTR_TIMEOUT] = { .type = NLA_U64 }, + [NBD_ATTR_SERVER_FLAGS] = { .type = NLA_U64 }, + [NBD_ATTR_CLIENT_FLAGS] = { .type = NLA_U64 }, + [NBD_ATTR_SOCKETS] = { .type = NLA_NESTED}, +}; + +static struct nla_policy nbd_sock_policy[NBD_SOCK_MAX + 1] = { + [NBD_SOCK_FD] = { .type = NLA_U32 }, +}; + +static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info) +{ + struct nbd_device *nbd = NULL; + struct nbd_config *config; + int index = -1; + int ret; + + if (!netlink_capable(skb, CAP_SYS_ADMIN)) + return -EPERM; + + if (info->attrs[NBD_ATTR_INDEX]) + index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]); + if (!info->attrs[NBD_ATTR_SOCKETS]) { + printk(KERN_ERR "nbd: must specify at least one socket\n"); + return -EINVAL; + } + if (!info->attrs[NBD_ATTR_SIZE_BYTES]) { + printk(KERN_ERR "nbd: must specify a size in bytes for the device\n"); + return -EINVAL; + } +again: + mutex_lock(&nbd_index_mutex); + if (index == -1) { + ret = idr_for_each(&nbd_index_idr, &find_free_cb, &nbd); + if (ret == 0) { + int new_index; + new_index = nbd_dev_add(-1); + if (new_index < 0) { + mutex_unlock(&nbd_index_mutex); + printk(KERN_ERR "nbd: failed to add new device\n"); + return ret; + } + nbd = idr_find(&nbd_index_idr, new_index); + } + } else { + nbd = idr_find(&nbd_index_idr, index); + } + mutex_unlock(&nbd_index_mutex); + if (!nbd) { + printk(KERN_ERR "nbd: couldn't find device at index %d\n", + index); + return -EINVAL; + } + + mutex_lock(&nbd->config_lock); + if (refcount_read(&nbd->config_refs)) { + mutex_unlock(&nbd->config_lock); + if (index == -1) + goto again; + printk(KERN_ERR "nbd: nbd%d already in use\n", index); + return -EBUSY; + } + if (WARN_ON(nbd->config)) { + mutex_unlock(&nbd->config_lock); + return -EINVAL; + } + config = nbd->config = nbd_alloc_config(); + if (!nbd->config) { + mutex_unlock(&nbd->config_lock); + printk(KERN_ERR "nbd: couldn't allocate config\n"); + return -ENOMEM; + } + refcount_set(&nbd->config_refs, 1); + set_bit(NBD_BOUND, &config->runtime_flags); + + if (info->attrs[NBD_ATTR_SIZE_BYTES]) { + u64 bytes = nla_get_u64(info->attrs[NBD_ATTR_SIZE_BYTES]); + nbd_size_set(nbd, config->blksize, + div64_u64(bytes, config->blksize)); + } + if (info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]) { + u64 bsize = + nla_get_u64(info->attrs[NBD_ATTR_BLOCK_SIZE_BYTES]); + nbd_size_set(nbd, bsize, div64_u64(config->bytesize, bsize)); + } + 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_SERVER_FLAGS]) + config->flags = + nla_get_u64(info->attrs[NBD_ATTR_SERVER_FLAGS]); + 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_add_socket(nbd, fd, true); + if (ret) + goto out; + } + } + ret = nbd_start_device(nbd); +out: + mutex_unlock(&nbd->config_lock); + if (!ret) { + set_bit(NBD_HAS_CONFIG_REF, &config->runtime_flags); + refcount_inc(&nbd->config_refs); + nbd_connect_reply(info, nbd->index); + } + nbd_config_put(nbd); + return ret; +} + +static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info) +{ + struct nbd_device *nbd; + int index; + + if (!netlink_capable(skb, CAP_SYS_ADMIN)) + return -EPERM; + + if (!info->attrs[NBD_ATTR_INDEX]) { + printk(KERN_ERR "nbd: must specify an index to disconnect\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 device at index %d\n", + index); + return -EINVAL; + } + if (!refcount_inc_not_zero(&nbd->config_refs)) + return 0; + mutex_lock(&nbd->config_lock); + nbd_disconnect(nbd); + mutex_unlock(&nbd->config_lock); + if (test_and_clear_bit(NBD_HAS_CONFIG_REF, + &nbd->config->runtime_flags)) + nbd_config_put(nbd); + nbd_config_put(nbd); + return 0; +} + +static const struct genl_ops nbd_connect_genl_ops[] = { + { + .cmd = NBD_CMD_CONNECT, + .policy = nbd_attr_policy, + .doit = nbd_genl_connect, + }, + { + .cmd = NBD_CMD_DISCONNECT, + .policy = nbd_attr_policy, + .doit = nbd_genl_disconnect, + }, +}; + +static struct genl_family nbd_genl_family __ro_after_init = { + .hdrsize = 0, + .name = NBD_GENL_FAMILY_NAME, + .version = NBD_GENL_VERSION, + .module = THIS_MODULE, + .ops = nbd_connect_genl_ops, + .n_ops = ARRAY_SIZE(nbd_connect_genl_ops), + .maxattr = NBD_ATTR_MAX, +}; + +static void nbd_connect_reply(struct genl_info *info, int index) +{ + struct sk_buff *skb; + void *msg_head; + int ret; + + skb = genlmsg_new(nla_total_size(sizeof(u32)), GFP_KERNEL); + if (!skb) + return; + msg_head = genlmsg_put_reply(skb, info, &nbd_genl_family, 0, + NBD_CMD_CONNECT); + if (!msg_head) { + nlmsg_free(skb); + return; + } + ret = nla_put_u32(skb, NBD_ATTR_INDEX, index); + if (ret) { + nlmsg_free(skb); + return; + } + genlmsg_end(skb, msg_head); + genlmsg_reply(skb, info); +} static int __init nbd_init(void) { @@ -1358,6 +1616,11 @@ static int __init nbd_init(void) return -EIO; } + if (genl_register_family(&nbd_genl_family)) { + unregister_blkdev(NBD_MAJOR, "nbd"); + destroy_workqueue(recv_workqueue); + return -EINVAL; + } nbd_dbg_init(); mutex_lock(&nbd_index_mutex); @@ -1380,6 +1643,7 @@ static void __exit nbd_cleanup(void) idr_for_each(&nbd_index_idr, &nbd_exit_cb, NULL); idr_destroy(&nbd_index_idr); + genl_unregister_family(&nbd_genl_family); destroy_workqueue(recv_workqueue); unregister_blkdev(NBD_MAJOR, "nbd"); } diff --git a/include/uapi/linux/nbd-netlink.h b/include/uapi/linux/nbd-netlink.h new file mode 100644 index 000000000000..fd0f4e45f03e --- /dev/null +++ b/include/uapi/linux/nbd-netlink.h @@ -0,0 +1,69 @@ +/* + * Copyright (C) 2017 Facebook. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ +#ifndef _UAPILINUX_NBD_NETLINK_H +#define _UAPILINUX_NBD_NETLINK_H + +#define NBD_GENL_FAMILY_NAME "nbd" +#define NBD_GENL_VERSION 0x1 + +/* Configuration policy attributes, used for CONNECT */ +enum { + NBD_ATTR_UNSPEC, + NBD_ATTR_INDEX, + NBD_ATTR_SIZE_BYTES, + NBD_ATTR_BLOCK_SIZE_BYTES, + NBD_ATTR_TIMEOUT, + NBD_ATTR_SERVER_FLAGS, + NBD_ATTR_CLIENT_FLAGS, + NBD_ATTR_SOCKETS, + __NBD_ATTR_MAX, +}; +#define NBD_ATTR_MAX (__NBD_ATTR_MAX - 1) + +/* + * This is the format for multiple sockets with NBD_ATTR_SOCKETS + * + * [NBD_ATTR_SOCKETS] + * [NBD_SOCK_ITEM] + * [NBD_SOCK_FD] + * [NBD_SOCK_ITEM] + * [NBD_SOCK_FD] + */ +enum { + NBD_SOCK_ITEM_UNSPEC, + NBD_SOCK_ITEM, + __NBD_SOCK_ITEM_MAX, +}; +#define NBD_SOCK_ITEM_MAX (__NBD_SOCK_ITEM_MAX - 1) + +enum { + NBD_SOCK_UNSPEC, + NBD_SOCK_FD, + __NBD_SOCK_MAX, +}; +#define NBD_SOCK_MAX (__NBD_SOCK_MAX - 1) + +enum { + NBD_CMD_UNSPEC, + NBD_CMD_CONNECT, + NBD_CMD_DISCONNECT, + __NBD_CMD_MAX, +}; +#define NBD_CMD_MAX (__NBD_CMD_MAX - 1) + +#endif /* _UAPILINUX_NBD_NETLINK_H */ |