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path: root/drivers/block/nbd.c
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Diffstat (limited to 'drivers/block/nbd.c')
-rw-r--r--drivers/block/nbd.c316
1 files changed, 290 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");
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 04:38:20 +0100