| /* |
| * Network block device - make block devices work over TCP |
| * |
| * Note that you can not swap over this thing, yet. Seems to work but |
| * deadlocks sometimes - you can not swap over TCP in general. |
| * |
| * Copyright 1997-2000, 2008 Pavel Machek <pavel@ucw.cz> |
| * Parts copyright 2001 Steven Whitehouse <steve@chygwyn.com> |
| * |
| * This file is released under GPLv2 or later. |
| * |
| * (part of code stolen from loop.c) |
| */ |
| |
| #include <linux/major.h> |
| |
| #include <linux/blkdev.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/sched.h> |
| #include <linux/sched/mm.h> |
| #include <linux/fs.h> |
| #include <linux/bio.h> |
| #include <linux/stat.h> |
| #include <linux/errno.h> |
| #include <linux/file.h> |
| #include <linux/ioctl.h> |
| #include <linux/mutex.h> |
| #include <linux/compiler.h> |
| #include <linux/err.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <net/sock.h> |
| #include <linux/net.h> |
| #include <linux/kthread.h> |
| #include <linux/types.h> |
| #include <linux/debugfs.h> |
| #include <linux/blk-mq.h> |
| |
| #include <linux/uaccess.h> |
| #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); |
| static int nbd_total_devices = 0; |
| |
| struct nbd_sock { |
| struct socket *sock; |
| struct mutex tx_lock; |
| struct request *pending; |
| int sent; |
| bool dead; |
| int fallback_index; |
| int cookie; |
| }; |
| |
| struct recv_thread_args { |
| struct work_struct work; |
| struct nbd_device *nbd; |
| int index; |
| }; |
| |
| struct link_dead_args { |
| struct work_struct work; |
| int index; |
| }; |
| |
| #define NBD_TIMEDOUT 0 |
| #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 |
| #define NBD_DESTROY_ON_DISCONNECT 6 |
| |
| struct nbd_config { |
| u32 flags; |
| unsigned long runtime_flags; |
| u64 dead_conn_timeout; |
| |
| struct nbd_sock **socks; |
| int num_connections; |
| atomic_t live_connections; |
| wait_queue_head_t conn_wait; |
| |
| atomic_t recv_threads; |
| wait_queue_head_t recv_wq; |
| loff_t blksize; |
| loff_t bytesize; |
| #if IS_ENABLED(CONFIG_DEBUG_FS) |
| struct dentry *dbg_dir; |
| #endif |
| }; |
| |
| struct nbd_device { |
| struct blk_mq_tag_set tag_set; |
| |
| int index; |
| refcount_t config_refs; |
| refcount_t refs; |
| struct nbd_config *config; |
| struct mutex config_lock; |
| struct gendisk *disk; |
| |
| struct list_head list; |
| struct task_struct *task_recv; |
| struct task_struct *task_setup; |
| }; |
| |
| struct nbd_cmd { |
| struct nbd_device *nbd; |
| int index; |
| int cookie; |
| struct completion send_complete; |
| blk_status_t status; |
| }; |
| |
| #if IS_ENABLED(CONFIG_DEBUG_FS) |
| static struct dentry *nbd_dbg_dir; |
| #endif |
| |
| #define nbd_name(nbd) ((nbd)->disk->disk_name) |
| |
| #define NBD_MAGIC 0x68797548 |
| |
| static unsigned int nbds_max = 16; |
| static int max_part = 16; |
| static struct workqueue_struct *recv_workqueue; |
| 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 int nbd_genl_status(struct sk_buff *skb, struct genl_info *info); |
| static void nbd_dead_link_work(struct work_struct *work); |
| |
| static inline struct device *nbd_to_dev(struct nbd_device *nbd) |
| { |
| return disk_to_dev(nbd->disk); |
| } |
| |
| static const char *nbdcmd_to_ascii(int cmd) |
| { |
| switch (cmd) { |
| case NBD_CMD_READ: return "read"; |
| case NBD_CMD_WRITE: return "write"; |
| case NBD_CMD_DISC: return "disconnect"; |
| case NBD_CMD_FLUSH: return "flush"; |
| case NBD_CMD_TRIM: return "trim/discard"; |
| } |
| return "invalid"; |
| } |
| |
| static ssize_t pid_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, "%d\n", task_pid_nr(nbd->task_recv)); |
| } |
| |
| static const struct device_attribute pid_attr = { |
| .attr = { .name = "pid", .mode = S_IRUGO}, |
| .show = pid_show, |
| }; |
| |
| static void nbd_dev_remove(struct nbd_device *nbd) |
| { |
| struct gendisk *disk = nbd->disk; |
| struct request_queue *q; |
| |
| if (disk) { |
| q = disk->queue; |
| del_gendisk(disk); |
| blk_cleanup_queue(q); |
| blk_mq_free_tag_set(&nbd->tag_set); |
| disk->private_data = NULL; |
| put_disk(disk); |
| } |
| kfree(nbd); |
| } |
| |
| static void nbd_put(struct nbd_device *nbd) |
| { |
| if (refcount_dec_and_mutex_lock(&nbd->refs, |
| &nbd_index_mutex)) { |
| idr_remove(&nbd_index_idr, nbd->index); |
| mutex_unlock(&nbd_index_mutex); |
| nbd_dev_remove(nbd); |
| } |
| } |
| |
| static int nbd_disconnected(struct nbd_config *config) |
| { |
| return test_bit(NBD_DISCONNECTED, &config->runtime_flags) || |
| test_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags); |
| } |
| |
| static void nbd_mark_nsock_dead(struct nbd_device *nbd, struct nbd_sock *nsock, |
| int notify) |
| { |
| if (!nsock->dead && notify && !nbd_disconnected(nbd->config)) { |
| struct link_dead_args *args; |
| args = kmalloc(sizeof(struct link_dead_args), GFP_NOIO); |
| if (args) { |
| INIT_WORK(&args->work, nbd_dead_link_work); |
| args->index = nbd->index; |
| queue_work(system_wq, &args->work); |
| } |
| } |
| if (!nsock->dead) { |
| kernel_sock_shutdown(nsock->sock, SHUT_RDWR); |
| atomic_dec(&nbd->config->live_connections); |
| } |
| nsock->dead = true; |
| nsock->pending = NULL; |
| nsock->sent = 0; |
| } |
| |
| static void nbd_size_clear(struct nbd_device *nbd) |
| { |
| if (nbd->config->bytesize) { |
| set_capacity(nbd->disk, 0); |
| kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); |
| } |
| } |
| |
| static void nbd_size_update(struct nbd_device *nbd) |
| { |
| struct nbd_config *config = nbd->config; |
| struct block_device *bdev = bdget_disk(nbd->disk, 0); |
| |
| blk_queue_logical_block_size(nbd->disk->queue, config->blksize); |
| blk_queue_physical_block_size(nbd->disk->queue, config->blksize); |
| set_capacity(nbd->disk, config->bytesize >> 9); |
| if (bdev) { |
| if (bdev->bd_disk) |
| bd_set_size(bdev, config->bytesize); |
| else |
| bdev->bd_invalidated = 1; |
| bdput(bdev); |
| } |
| kobject_uevent(&nbd_to_dev(nbd)->kobj, KOBJ_CHANGE); |
| } |
| |
| static void nbd_size_set(struct nbd_device *nbd, loff_t blocksize, |
| loff_t nr_blocks) |
| { |
| struct nbd_config *config = nbd->config; |
| config->blksize = blocksize; |
| config->bytesize = blocksize * nr_blocks; |
| if (nbd->task_recv != NULL) |
| nbd_size_update(nbd); |
| } |
| |
| static void nbd_complete_rq(struct request *req) |
| { |
| struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req); |
| |
| dev_dbg(nbd_to_dev(cmd->nbd), "request %p: %s\n", cmd, |
| cmd->status ? "failed" : "done"); |
| |
| blk_mq_end_request(req, cmd->status); |
| } |
| |
| /* |
| * Forcibly shutdown the socket causing all listeners to error |
| */ |
| static void sock_shutdown(struct nbd_device *nbd) |
| { |
| struct nbd_config *config = nbd->config; |
| int i; |
| |
| if (config->num_connections == 0) |
| return; |
| if (test_and_set_bit(NBD_DISCONNECTED, &config->runtime_flags)) |
| return; |
| |
| for (i = 0; i < config->num_connections; i++) { |
| struct nbd_sock *nsock = config->socks[i]; |
| mutex_lock(&nsock->tx_lock); |
| nbd_mark_nsock_dead(nbd, nsock, 0); |
| mutex_unlock(&nsock->tx_lock); |
| } |
| dev_warn(disk_to_dev(nbd->disk), "shutting down sockets\n"); |
| } |
| |
| static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, |
| bool reserved) |
| { |
| struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req); |
| struct nbd_device *nbd = cmd->nbd; |
| struct nbd_config *config; |
| |
| if (!refcount_inc_not_zero(&nbd->config_refs)) { |
| cmd->status = BLK_STS_TIMEOUT; |
| return BLK_EH_HANDLED; |
| } |
| config = nbd->config; |
| |
| if (config->num_connections > 1) { |
| dev_err_ratelimited(nbd_to_dev(nbd), |
| "Connection timed out, retrying\n"); |
| /* |
| * Hooray we have more connections, requeue this IO, the submit |
| * path will put it on a real connection. |
| */ |
| if (config->socks && config->num_connections > 1) { |
| if (cmd->index < config->num_connections) { |
| struct nbd_sock *nsock = |
| config->socks[cmd->index]; |
| mutex_lock(&nsock->tx_lock); |
| /* We can have multiple outstanding requests, so |
| * we don't want to mark the nsock dead if we've |
| * already reconnected with a new socket, so |
| * only mark it dead if its the same socket we |
| * were sent out on. |
| */ |
| if (cmd->cookie == nsock->cookie) |
| nbd_mark_nsock_dead(nbd, nsock, 1); |
| mutex_unlock(&nsock->tx_lock); |
| } |
| blk_mq_requeue_request(req, true); |
| nbd_config_put(nbd); |
| return BLK_EH_NOT_HANDLED; |
| } |
| } else { |
| dev_err_ratelimited(nbd_to_dev(nbd), |
| "Connection timed out\n"); |
| } |
| set_bit(NBD_TIMEDOUT, &config->runtime_flags); |
| cmd->status = BLK_STS_IOERR; |
| sock_shutdown(nbd); |
| nbd_config_put(nbd); |
| |
| return BLK_EH_HANDLED; |
| } |
| |
| /* |
| * Send or receive packet. |
| */ |
| static int sock_xmit(struct nbd_device *nbd, int index, int send, |
| struct iov_iter *iter, int msg_flags, int *sent) |
| { |
| struct nbd_config *config = nbd->config; |
| struct socket *sock = config->socks[index]->sock; |
| int result; |
| struct msghdr msg; |
| unsigned int noreclaim_flag; |
| |
| if (unlikely(!sock)) { |
| dev_err_ratelimited(disk_to_dev(nbd->disk), |
| "Attempted %s on closed socket in sock_xmit\n", |
| (send ? "send" : "recv")); |
| return -EINVAL; |
| } |
| |
| msg.msg_iter = *iter; |
| |
| noreclaim_flag = memalloc_noreclaim_save(); |
| do { |
| sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC; |
| msg.msg_name = NULL; |
| msg.msg_namelen = 0; |
| msg.msg_control = NULL; |
| msg.msg_controllen = 0; |
| msg.msg_flags = msg_flags | MSG_NOSIGNAL; |
| |
| if (send) |
| result = sock_sendmsg(sock, &msg); |
| else |
| result = sock_recvmsg(sock, &msg, msg.msg_flags); |
| |
| if (result <= 0) { |
| if (result == 0) |
| result = -EPIPE; /* short read */ |
| break; |
| } |
| if (sent) |
| *sent += result; |
| } while (msg_data_left(&msg)); |
| |
| memalloc_noreclaim_restore(noreclaim_flag); |
| |
| return result; |
| } |
| |
| /* |
| * Different settings for sk->sk_sndtimeo can result in different return values |
| * if there is a signal pending when we enter sendmsg, because reasons? |
| */ |
| static inline int was_interrupted(int result) |
| { |
| return result == -ERESTARTSYS || result == -EINTR; |
| } |
| |
| /* always call with the tx_lock held */ |
| static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) |
| { |
| struct request *req = blk_mq_rq_from_pdu(cmd); |
| struct nbd_config *config = nbd->config; |
| struct nbd_sock *nsock = config->socks[index]; |
| int result; |
| struct nbd_request request = {.magic = htonl(NBD_REQUEST_MAGIC)}; |
| struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)}; |
| struct iov_iter from; |
| unsigned long size = blk_rq_bytes(req); |
| struct bio *bio; |
| u32 type; |
| u32 nbd_cmd_flags = 0; |
| u32 tag = blk_mq_unique_tag(req); |
| int sent = nsock->sent, skip = 0; |
| |
| iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request)); |
| |
| switch (req_op(req)) { |
| case REQ_OP_DISCARD: |
| type = NBD_CMD_TRIM; |
| break; |
| case REQ_OP_FLUSH: |
| type = NBD_CMD_FLUSH; |
| break; |
| case REQ_OP_WRITE: |
| type = NBD_CMD_WRITE; |
| break; |
| case REQ_OP_READ: |
| type = NBD_CMD_READ; |
| break; |
| default: |
| return -EIO; |
| } |
| |
| if (rq_data_dir(req) == WRITE && |
| (config->flags & NBD_FLAG_READ_ONLY)) { |
| dev_err_ratelimited(disk_to_dev(nbd->disk), |
| "Write on read-only\n"); |
| return -EIO; |
| } |
| |
| if (req->cmd_flags & REQ_FUA) |
| nbd_cmd_flags |= NBD_CMD_FLAG_FUA; |
| |
| /* We did a partial send previously, and we at least sent the whole |
| * request struct, so just go and send the rest of the pages in the |
| * request. |
| */ |
| if (sent) { |
| if (sent >= sizeof(request)) { |
| skip = sent - sizeof(request); |
| goto send_pages; |
| } |
| iov_iter_advance(&from, sent); |
| } |
| cmd->index = index; |
| cmd->cookie = nsock->cookie; |
| request.type = htonl(type | nbd_cmd_flags); |
| if (type != NBD_CMD_FLUSH) { |
| request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9); |
| request.len = htonl(size); |
| } |
| memcpy(request.handle, &tag, sizeof(tag)); |
| |
| dev_dbg(nbd_to_dev(nbd), "request %p: sending control (%s@%llu,%uB)\n", |
| cmd, nbdcmd_to_ascii(type), |
| (unsigned long long)blk_rq_pos(req) << 9, blk_rq_bytes(req)); |
| result = sock_xmit(nbd, index, 1, &from, |
| (type == NBD_CMD_WRITE) ? MSG_MORE : 0, &sent); |
| if (result <= 0) { |
| if (was_interrupted(result)) { |
| /* If we havne't sent anything we can just return BUSY, |
| * however if we have sent something we need to make |
| * sure we only allow this req to be sent until we are |
| * completely done. |
| */ |
| if (sent) { |
| nsock->pending = req; |
| nsock->sent = sent; |
| } |
| return BLK_STS_RESOURCE; |
| } |
| dev_err_ratelimited(disk_to_dev(nbd->disk), |
| "Send control failed (result %d)\n", result); |
| return -EAGAIN; |
| } |
| send_pages: |
| if (type != NBD_CMD_WRITE) |
| goto out; |
| |
| bio = req->bio; |
| while (bio) { |
| struct bio *next = bio->bi_next; |
| struct bvec_iter iter; |
| struct bio_vec bvec; |
| |
| bio_for_each_segment(bvec, bio, iter) { |
| bool is_last = !next && bio_iter_last(bvec, iter); |
| int flags = is_last ? 0 : MSG_MORE; |
| |
| dev_dbg(nbd_to_dev(nbd), "request %p: sending %d bytes data\n", |
| cmd, bvec.bv_len); |
| iov_iter_bvec(&from, ITER_BVEC | WRITE, |
| &bvec, 1, bvec.bv_len); |
| if (skip) { |
| if (skip >= iov_iter_count(&from)) { |
| skip -= iov_iter_count(&from); |
| continue; |
| } |
| iov_iter_advance(&from, skip); |
| skip = 0; |
| } |
| result = sock_xmit(nbd, index, 1, &from, flags, &sent); |
| if (result <= 0) { |
| if (was_interrupted(result)) { |
| /* We've already sent the header, we |
| * have no choice but to set pending and |
| * return BUSY. |
| */ |
| nsock->pending = req; |
| nsock->sent = sent; |
| return BLK_STS_RESOURCE; |
| } |
| dev_err(disk_to_dev(nbd->disk), |
| "Send data failed (result %d)\n", |
| result); |
| return -EAGAIN; |
| } |
| /* |
| * The completion might already have come in, |
| * so break for the last one instead of letting |
| * the iterator do it. This prevents use-after-free |
| * of the bio. |
| */ |
| if (is_last) |
| break; |
| } |
| bio = next; |
| } |
| out: |
| nsock->pending = NULL; |
| nsock->sent = 0; |
| return 0; |
| } |
| |
| /* NULL returned = something went wrong, inform userspace */ |
| static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) |
| { |
| struct nbd_config *config = nbd->config; |
| int result; |
| struct nbd_reply reply; |
| struct nbd_cmd *cmd; |
| struct request *req = NULL; |
| u16 hwq; |
| u32 tag; |
| struct kvec iov = {.iov_base = &reply, .iov_len = sizeof(reply)}; |
| struct iov_iter to; |
| |
| reply.magic = 0; |
| iov_iter_kvec(&to, READ | ITER_KVEC, &iov, 1, sizeof(reply)); |
| result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL); |
| if (result <= 0) { |
| if (!nbd_disconnected(config)) |
| dev_err(disk_to_dev(nbd->disk), |
| "Receive control failed (result %d)\n", result); |
| return ERR_PTR(result); |
| } |
| |
| if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { |
| dev_err(disk_to_dev(nbd->disk), "Wrong magic (0x%lx)\n", |
| (unsigned long)ntohl(reply.magic)); |
| return ERR_PTR(-EPROTO); |
| } |
| |
| memcpy(&tag, reply.handle, sizeof(u32)); |
| |
| hwq = blk_mq_unique_tag_to_hwq(tag); |
| if (hwq < nbd->tag_set.nr_hw_queues) |
| req = blk_mq_tag_to_rq(nbd->tag_set.tags[hwq], |
| blk_mq_unique_tag_to_tag(tag)); |
| if (!req || !blk_mq_request_started(req)) { |
| dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%d) %p\n", |
| tag, req); |
| return ERR_PTR(-ENOENT); |
| } |
| cmd = blk_mq_rq_to_pdu(req); |
| if (ntohl(reply.error)) { |
| dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n", |
| ntohl(reply.error)); |
| cmd->status = BLK_STS_IOERR; |
| return cmd; |
| } |
| |
| dev_dbg(nbd_to_dev(nbd), "request %p: got reply\n", cmd); |
| if (rq_data_dir(req) != WRITE) { |
| struct req_iterator iter; |
| struct bio_vec bvec; |
| |
| rq_for_each_segment(bvec, req, iter) { |
| iov_iter_bvec(&to, ITER_BVEC | READ, |
| &bvec, 1, bvec.bv_len); |
| result = sock_xmit(nbd, index, 0, &to, MSG_WAITALL, NULL); |
| if (result <= 0) { |
| dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", |
| result); |
| /* |
| * If we've disconnected or we only have 1 |
| * connection then we need to make sure we |
| * complete this request, otherwise error out |
| * and let the timeout stuff handle resubmitting |
| * this request onto another connection. |
| */ |
| if (nbd_disconnected(config) || |
| config->num_connections <= 1) { |
| cmd->status = BLK_STS_IOERR; |
| return cmd; |
| } |
| return ERR_PTR(-EIO); |
| } |
| dev_dbg(nbd_to_dev(nbd), "request %p: got %d bytes data\n", |
| cmd, bvec.bv_len); |
| } |
| } else { |
| /* See the comment in nbd_queue_rq. */ |
| wait_for_completion(&cmd->send_complete); |
| } |
| return cmd; |
| } |
| |
| static void recv_work(struct work_struct *work) |
| { |
| struct recv_thread_args *args = container_of(work, |
| struct recv_thread_args, |
| work); |
| struct nbd_device *nbd = args->nbd; |
| struct nbd_config *config = nbd->config; |
| struct nbd_cmd *cmd; |
| |
| while (1) { |
| cmd = nbd_read_stat(nbd, args->index); |
| if (IS_ERR(cmd)) { |
| struct nbd_sock *nsock = config->socks[args->index]; |
| |
| mutex_lock(&nsock->tx_lock); |
| nbd_mark_nsock_dead(nbd, nsock, 1); |
| mutex_unlock(&nsock->tx_lock); |
| break; |
| } |
| |
| blk_mq_complete_request(blk_mq_rq_from_pdu(cmd)); |
| } |
| atomic_dec(&config->recv_threads); |
| wake_up(&config->recv_wq); |
| nbd_config_put(nbd); |
| kfree(args); |
| } |
| |
| static void nbd_clear_req(struct request *req, void *data, bool reserved) |
| { |
| struct nbd_cmd *cmd; |
| |
| if (!blk_mq_request_started(req)) |
| return; |
| cmd = blk_mq_rq_to_pdu(req); |
| cmd->status = BLK_STS_IOERR; |
| blk_mq_complete_request(req); |
| } |
| |
| static void nbd_clear_que(struct nbd_device *nbd) |
| { |
| blk_mq_quiesce_queue(nbd->disk->queue); |
| blk_mq_tagset_busy_iter(&nbd->tag_set, nbd_clear_req, NULL); |
| blk_mq_unquiesce_queue(nbd->disk->queue); |
| dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n"); |
| } |
| |
| static int find_fallback(struct nbd_device *nbd, int index) |
| { |
| struct nbd_config *config = nbd->config; |
| int new_index = -1; |
| struct nbd_sock *nsock = config->socks[index]; |
| int fallback = nsock->fallback_index; |
| |
| if (test_bit(NBD_DISCONNECTED, &config->runtime_flags)) |
| return new_index; |
| |
| if (config->num_connections <= 1) { |
| dev_err_ratelimited(disk_to_dev(nbd->disk), |
| "Attempted send on invalid socket\n"); |
| return new_index; |
| } |
| |
| if (fallback >= 0 && fallback < config->num_connections && |
| !config->socks[fallback]->dead) |
| return fallback; |
| |
| if (nsock->fallback_index < 0 || |
| nsock->fallback_index >= config->num_connections || |
| config->socks[nsock->fallback_index]->dead) { |
| int i; |
| for (i = 0; i < config->num_connections; i++) { |
| if (i == index) |
| continue; |
| if (!config->socks[i]->dead) { |
| new_index = i; |
| break; |
| } |
| } |
| nsock->fallback_index = new_index; |
| if (new_index < 0) { |
| dev_err_ratelimited(disk_to_dev(nbd->disk), |
| "Dead connection, failed to find a fallback\n"); |
| return new_index; |
| } |
| } |
| new_index = nsock->fallback_index; |
| return new_index; |
| } |
| |
| static int wait_for_reconnect(struct nbd_device *nbd) |
| { |
| struct nbd_config *config = nbd->config; |
| if (!config->dead_conn_timeout) |
| return 0; |
| if (test_bit(NBD_DISCONNECTED, &config->runtime_flags)) |
| return 0; |
| wait_event_timeout(config->conn_wait, |
| atomic_read(&config->live_connections), |
| config->dead_conn_timeout); |
| return atomic_read(&config->live_connections); |
| } |
| |
| static int nbd_handle_cmd(struct nbd_cmd *cmd, int index) |
| { |
| struct request *req = blk_mq_rq_from_pdu(cmd); |
| struct nbd_device *nbd = cmd->nbd; |
| struct nbd_config *config; |
| struct nbd_sock *nsock; |
| int ret; |
| |
| if (!refcount_inc_not_zero(&nbd->config_refs)) { |
| dev_err_ratelimited(disk_to_dev(nbd->disk), |
| "Socks array is empty\n"); |
| blk_mq_start_request(req); |
| return -EINVAL; |
| } |
| config = nbd->config; |
| |
| if (index >= config->num_connections) { |
| dev_err_ratelimited(disk_to_dev(nbd->disk), |
| "Attempted send on invalid socket\n"); |
| nbd_config_put(nbd); |
| blk_mq_start_request(req); |
| return -EINVAL; |
| } |
| cmd->status = BLK_STS_OK; |
| again: |
| nsock = config->socks[index]; |
| mutex_lock(&nsock->tx_lock); |
| if (nsock->dead) { |
| int old_index = index; |
| index = find_fallback(nbd, index); |
| mutex_unlock(&nsock->tx_lock); |
| if (index < 0) { |
| if (wait_for_reconnect(nbd)) { |
| index = old_index; |
| goto again; |
| } |
| /* All the sockets should already be down at this point, |
| * we just want to make sure that DISCONNECTED is set so |
| * any requests that come in that were queue'ed waiting |
| * for the reconnect timer don't trigger the timer again |
| * and instead just error out. |
| */ |
| sock_shutdown(nbd); |
| nbd_config_put(nbd); |
| blk_mq_start_request(req); |
| return -EIO; |
| } |
| goto again; |
| } |
| |
| /* Handle the case that we have a pending request that was partially |
| * transmitted that _has_ to be serviced first. We need to call requeue |
| * here so that it gets put _after_ the request that is already on the |
| * dispatch list. |
| */ |
| blk_mq_start_request(req); |
| if (unlikely(nsock->pending && nsock->pending != req)) { |
| blk_mq_requeue_request(req, true); |
| ret = 0; |
| goto out; |
| } |
| /* |
| * Some failures are related to the link going down, so anything that |
| * returns EAGAIN can be retried on a different socket. |
| */ |
| ret = nbd_send_cmd(nbd, cmd, index); |
| if (ret == -EAGAIN) { |
| dev_err_ratelimited(disk_to_dev(nbd->disk), |
| "Request send failed, requeueing\n"); |
| nbd_mark_nsock_dead(nbd, nsock, 1); |
| blk_mq_requeue_request(req, true); |
| ret = 0; |
| } |
| out: |
| mutex_unlock(&nsock->tx_lock); |
| nbd_config_put(nbd); |
| return ret; |
| } |
| |
| static blk_status_t nbd_queue_rq(struct blk_mq_hw_ctx *hctx, |
| const struct blk_mq_queue_data *bd) |
| { |
| struct nbd_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); |
| int ret; |
| |
| /* |
| * Since we look at the bio's to send the request over the network we |
| * need to make sure the completion work doesn't mark this request done |
| * before we are done doing our send. This keeps us from dereferencing |
| * freed data if we have particularly fast completions (ie we get the |
| * completion before we exit sock_xmit on the last bvec) or in the case |
| * that the server is misbehaving (or there was an error) before we're |
| * done sending everything over the wire. |
| */ |
| init_completion(&cmd->send_complete); |
| |
| /* We can be called directly from the user space process, which means we |
| * could possibly have signals pending so our sendmsg will fail. In |
| * this case we need to return that we are busy, otherwise error out as |
| * appropriate. |
| */ |
| ret = nbd_handle_cmd(cmd, hctx->queue_num); |
| if (ret < 0) |
| ret = BLK_STS_IOERR; |
| else if (!ret) |
| ret = BLK_STS_OK; |
| complete(&cmd->send_complete); |
| |
| return ret; |
| } |
| |
| static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg, |
| bool netlink) |
| { |
| struct nbd_config *config = nbd->config; |
| struct socket *sock; |
| struct nbd_sock **socks; |
| struct nbd_sock *nsock; |
| int err; |
| |
| sock = sockfd_lookup(arg, &err); |
| if (!sock) |
| return err; |
| |
| if (!netlink && !nbd->task_setup && |
| !test_bit(NBD_BOUND, &config->runtime_flags)) |
| 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 -EBUSY; |
| } |
| |
| socks = krealloc(config->socks, (config->num_connections + 1) * |
| sizeof(struct nbd_sock *), GFP_KERNEL); |
| if (!socks) { |
| sockfd_put(sock); |
| return -ENOMEM; |
| } |
| nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL); |
| if (!nsock) { |
| sockfd_put(sock); |
| return -ENOMEM; |
| } |
| |
| config->socks = socks; |
| |
| nsock->fallback_index = -1; |
| nsock->dead = false; |
| mutex_init(&nsock->tx_lock); |
| nsock->sock = sock; |
| nsock->pending = NULL; |
| nsock->sent = 0; |
| nsock->cookie = 0; |
| socks[config->num_connections++] = nsock; |
| atomic_inc(&config->live_connections); |
| |
| 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); |
| if (nbd->tag_set.timeout) |
| sock->sk->sk_sndtimeo = nbd->tag_set.timeout; |
| 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; |
| nsock->cookie++; |
| mutex_unlock(&nsock->tx_lock); |
| sockfd_put(old); |
| |
| clear_bit(NBD_DISCONNECTED, &config->runtime_flags); |
| |
| /* 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); |
| |
| atomic_inc(&config->live_connections); |
| wake_up(&config->conn_wait); |
| return 0; |
| } |
| sockfd_put(sock); |
| kfree(args); |
| return -ENOSPC; |
| } |
| |
| static void nbd_bdev_reset(struct block_device *bdev) |
| { |
| if (bdev->bd_openers > 1) |
| return; |
| bd_set_size(bdev, 0); |
| if (max_part > 0) { |
| blkdev_reread_part(bdev); |
| bdev->bd_invalidated = 1; |
| } |
| } |
| |
| static void nbd_parse_flags(struct nbd_device *nbd) |
| { |
| struct nbd_config *config = nbd->config; |
| if (config->flags & NBD_FLAG_READ_ONLY) |
| set_disk_ro(nbd->disk, true); |
| else |
| set_disk_ro(nbd->disk, false); |
| if (config->flags & NBD_FLAG_SEND_TRIM) |
| blk_queue_flag_set(QUEUE_FLAG_DISCARD, nbd->disk->queue); |
| if (config->flags & NBD_FLAG_SEND_FLUSH) { |
| if (config->flags & NBD_FLAG_SEND_FUA) |
| blk_queue_write_cache(nbd->disk->queue, true, true); |
| else |
| blk_queue_write_cache(nbd->disk->queue, true, false); |
| } |
| else |
| blk_queue_write_cache(nbd->disk->queue, false, false); |
| } |
| |
| static void send_disconnects(struct nbd_device *nbd) |
| { |
| struct nbd_config *config = nbd->config; |
| struct nbd_request request = { |
| .magic = htonl(NBD_REQUEST_MAGIC), |
| .type = htonl(NBD_CMD_DISC), |
| }; |
| struct kvec iov = {.iov_base = &request, .iov_len = sizeof(request)}; |
| struct iov_iter from; |
| int i, ret; |
| |
| for (i = 0; i < config->num_connections; i++) { |
| struct nbd_sock *nsock = config->socks[i]; |
| |
| iov_iter_kvec(&from, WRITE | ITER_KVEC, &iov, 1, sizeof(request)); |
| mutex_lock(&nsock->tx_lock); |
| ret = sock_xmit(nbd, i, 1, &from, 0, NULL); |
| if (ret <= 0) |
| dev_err(disk_to_dev(nbd->disk), |
| "Send disconnect failed %d\n", ret); |
| mutex_unlock(&nsock->tx_lock); |
| } |
| } |
| |
| static int nbd_disconnect(struct nbd_device *nbd) |
| { |
| struct nbd_config *config = nbd->config; |
| |
| dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n"); |
| set_bit(NBD_DISCONNECT_REQUESTED, &config->runtime_flags); |
| send_disconnects(nbd); |
| return 0; |
| } |
| |
| static void nbd_clear_sock(struct nbd_device *nbd) |
| { |
| sock_shutdown(nbd); |
| nbd_clear_que(nbd); |
| nbd->task_setup = NULL; |
| } |
| |
| static void nbd_config_put(struct nbd_device *nbd) |
| { |
| if (refcount_dec_and_mutex_lock(&nbd->config_refs, |
| &nbd->config_lock)) { |
| struct nbd_config *config = nbd->config; |
| nbd_dev_dbg_close(nbd); |
| nbd_size_clear(nbd); |
| if (test_and_clear_bit(NBD_HAS_PID_FILE, |
| &config->runtime_flags)) |
| device_remove_file(disk_to_dev(nbd->disk), &pid_attr); |
| nbd->task_recv = NULL; |
| nbd_clear_sock(nbd); |
| if (config->num_connections) { |
| int i; |
| for (i = 0; i < config->num_connections; i++) { |
| sockfd_put(config->socks[i]->sock); |
| kfree(config->socks[i]); |
| } |
| kfree(config->socks); |
| } |
| kfree(nbd->config); |
| nbd->config = NULL; |
| |
| nbd->tag_set.timeout = 0; |
| blk_queue_flag_clear(QUEUE_FLAG_DISCARD, nbd->disk->queue); |
| |
| mutex_unlock(&nbd->config_lock); |
| nbd_put(nbd); |
| module_put(THIS_MODULE); |
| } |
| } |
| |
| static int nbd_start_device(struct nbd_device *nbd) |
| { |
| struct nbd_config *config = nbd->config; |
| int num_connections = config->num_connections; |
| int error = 0, i; |
| |
| if (nbd->task_recv) |
| return -EBUSY; |
| if (!config->socks) |
| return -EINVAL; |
| if (num_connections > 1 && |
| !(config->flags & NBD_FLAG_CAN_MULTI_CONN)) { |
| dev_err(disk_to_dev(nbd->disk), "server does not support multiple connections per device.\n"); |
| return -EINVAL; |
| } |
| |
| blk_mq_update_nr_hw_queues(&nbd->tag_set, config->num_connections); |
| nbd->task_recv = current; |
| |
| nbd_parse_flags(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"); |
| return error; |
| } |
| set_bit(NBD_HAS_PID_FILE, &config->runtime_flags); |
| |
| nbd_dev_dbg_init(nbd); |
| for (i = 0; i < num_connections; i++) { |
| struct recv_thread_args *args; |
| |
| args = kzalloc(sizeof(*args), GFP_KERNEL); |
| if (!args) { |
| sock_shutdown(nbd); |
| return -ENOMEM; |
| } |
| sk_set_memalloc(config->socks[i]->sock->sk); |
| if (nbd->tag_set.timeout) |
| config->socks[i]->sock->sk->sk_sndtimeo = |
| nbd->tag_set.timeout; |
| atomic_inc(&config->recv_threads); |
| refcount_inc(&nbd->config_refs); |
| INIT_WORK(&args->work, recv_work); |
| args->nbd = nbd; |
| args->index = i; |
| queue_work(recv_workqueue, &args->work); |
| } |
| nbd_size_update(nbd); |
| 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; |
| |
| 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 (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)) |
| ret = 0; |
| if (test_bit(NBD_TIMEDOUT, &config->runtime_flags)) |
| ret = -ETIMEDOUT; |
| return ret; |
| } |
| |
| static void nbd_clear_sock_ioctl(struct nbd_device *nbd, |
| struct block_device *bdev) |
| { |
| sock_shutdown(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 */ |
| static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct nbd_config *config = nbd->config; |
| |
| switch (cmd) { |
| case NBD_DISCONNECT: |
| return nbd_disconnect(nbd); |
| case NBD_CLEAR_SOCK: |
| nbd_clear_sock_ioctl(nbd, bdev); |
| return 0; |
| case NBD_SET_SOCK: |
| return nbd_add_socket(nbd, arg, false); |
| case NBD_SET_BLKSIZE: |
| nbd_size_set(nbd, arg, |
| div_s64(config->bytesize, arg)); |
| return 0; |
| case NBD_SET_SIZE: |
| nbd_size_set(nbd, config->blksize, |
| div_s64(arg, config->blksize)); |
| return 0; |
| case NBD_SET_SIZE_BLOCKS: |
| nbd_size_set(nbd, config->blksize, arg); |
| return 0; |
| case NBD_SET_TIMEOUT: |
| if (arg) { |
| nbd->tag_set.timeout = arg * HZ; |
| blk_queue_rq_timeout(nbd->disk->queue, arg * HZ); |
| } |
| return 0; |
| |
| case NBD_SET_FLAGS: |
| config->flags = arg; |
| return 0; |
| case NBD_DO_IT: |
| return nbd_start_device_ioctl(nbd, bdev); |
| case NBD_CLEAR_QUE: |
| /* |
| * This is for compatibility only. The queue is always cleared |
| * by NBD_DO_IT or NBD_CLEAR_SOCK. |
| */ |
| return 0; |
| case NBD_PRINT_DEBUG: |
| /* |
| * For compatibility only, we no longer keep a list of |
| * outstanding requests. |
| */ |
| return 0; |
| } |
| return -ENOTTY; |
| } |
| |
| 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; |
| struct nbd_config *config = nbd->config; |
| int error = -EINVAL; |
| |
| if (!capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| |
| /* The block layer will pass back some non-nbd ioctls in case we have |
| * special handling for them, but we don't so just return an error. |
| */ |
| if (_IOC_TYPE(cmd) != 0xab) |
| return -EINVAL; |
| |
| mutex_lock(&nbd->config_lock); |
| |
| /* 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; |
| } |
| |
| static struct nbd_config *nbd_alloc_config(void) |
| { |
| struct nbd_config *config; |
| |
| config = kzalloc(sizeof(struct nbd_config), GFP_NOFS); |
| if (!config) |
| return NULL; |
| atomic_set(&config->recv_threads, 0); |
| init_waitqueue_head(&config->recv_wq); |
| init_waitqueue_head(&config->conn_wait); |
| config->blksize = 1024; |
| atomic_set(&config->live_connections, 0); |
| try_module_get(THIS_MODULE); |
| return config; |
| } |
| |
| static int nbd_open(struct block_device *bdev, fmode_t mode) |
| { |
| struct nbd_device *nbd; |
| int ret = 0; |
| |
| mutex_lock(&nbd_index_mutex); |
| nbd = bdev->bd_disk->private_data; |
| if (!nbd) { |
| ret = -ENXIO; |
| goto out; |
| } |
| if (!refcount_inc_not_zero(&nbd->refs)) { |
| ret = -ENXIO; |
| goto out; |
| } |
| if (!refcount_inc_not_zero(&nbd->config_refs)) { |
| struct nbd_config *config; |
| |
| mutex_lock(&nbd->config_lock); |
| if (refcount_inc_not_zero(&nbd->config_refs)) { |
| mutex_unlock(&nbd->config_lock); |
| goto out; |
| } |
| config = nbd->config = nbd_alloc_config(); |
| if (!config) { |
| ret = -ENOMEM; |
| mutex_unlock(&nbd->config_lock); |
| goto out; |
| } |
| refcount_set(&nbd->config_refs, 1); |
| refcount_inc(&nbd->refs); |
| mutex_unlock(&nbd->config_lock); |
| } |
| out: |
| mutex_unlock(&nbd_index_mutex); |
| return ret; |
| } |
| |
| static void nbd_release(struct gendisk *disk, fmode_t mode) |
| { |
| struct nbd_device *nbd = disk->private_data; |
| nbd_config_put(nbd); |
| nbd_put(nbd); |
| } |
| |
| static const struct block_device_operations nbd_fops = |
| { |
| .owner = THIS_MODULE, |
| .open = nbd_open, |
| .release = nbd_release, |
| .ioctl = nbd_ioctl, |
| .compat_ioctl = nbd_ioctl, |
| }; |
| |
| #if IS_ENABLED(CONFIG_DEBUG_FS) |
| |
| static int nbd_dbg_tasks_show(struct seq_file *s, void *unused) |
| { |
| struct nbd_device *nbd = s->private; |
| |
| if (nbd->task_recv) |
| seq_printf(s, "recv: %d\n", task_pid_nr(nbd->task_recv)); |
| |
| return 0; |
| } |
| |
| static int nbd_dbg_tasks_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, nbd_dbg_tasks_show, inode->i_private); |
| } |
| |
| static const struct file_operations nbd_dbg_tasks_ops = { |
| .open = nbd_dbg_tasks_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = single_release, |
| }; |
| |
| static int nbd_dbg_flags_show(struct seq_file *s, void *unused) |
| { |
| struct nbd_device *nbd = s->private; |
| u32 flags = nbd->config->flags; |
| |
| seq_printf(s, "Hex: 0x%08x\n\n", flags); |
| |
| seq_puts(s, "Known flags:\n"); |
| |
| if (flags & NBD_FLAG_HAS_FLAGS) |
| seq_puts(s, "NBD_FLAG_HAS_FLAGS\n"); |
| if (flags & NBD_FLAG_READ_ONLY) |
| seq_puts(s, "NBD_FLAG_READ_ONLY\n"); |
| if (flags & NBD_FLAG_SEND_FLUSH) |
| seq_puts(s, "NBD_FLAG_SEND_FLUSH\n"); |
| if (flags & NBD_FLAG_SEND_FUA) |
| seq_puts(s, "NBD_FLAG_SEND_FUA\n"); |
| if (flags & NBD_FLAG_SEND_TRIM) |
| seq_puts(s, "NBD_FLAG_SEND_TRIM\n"); |
| |
| return 0; |
| } |
| |
| static int nbd_dbg_flags_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, nbd_dbg_flags_show, inode->i_private); |
| } |
| |
| static const struct file_operations nbd_dbg_flags_ops = { |
| .open = nbd_dbg_flags_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = single_release, |
| }; |
| |
| static int nbd_dev_dbg_init(struct nbd_device *nbd) |
| { |
| struct dentry *dir; |
| struct nbd_config *config = nbd->config; |
| |
| if (!nbd_dbg_dir) |
| return -EIO; |
| |
| dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir); |
| if (!dir) { |
| dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s'\n", |
| nbd_name(nbd)); |
| return -EIO; |
| } |
| config->dbg_dir = dir; |
| |
| debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops); |
| debugfs_create_u64("size_bytes", 0444, dir, &config->bytesize); |
| debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout); |
| debugfs_create_u64("blocksize", 0444, dir, &config->blksize); |
| debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops); |
| |
| return 0; |
| } |
| |
| static void nbd_dev_dbg_close(struct nbd_device *nbd) |
| { |
| debugfs_remove_recursive(nbd->config->dbg_dir); |
| } |
| |
| static int nbd_dbg_init(void) |
| { |
| struct dentry *dbg_dir; |
| |
| dbg_dir = debugfs_create_dir("nbd", NULL); |
| if (!dbg_dir) |
| return -EIO; |
| |
| nbd_dbg_dir = dbg_dir; |
| |
| return 0; |
| } |
| |
| static void nbd_dbg_close(void) |
| { |
| debugfs_remove_recursive(nbd_dbg_dir); |
| } |
| |
| #else /* IS_ENABLED(CONFIG_DEBUG_FS) */ |
| |
| static int nbd_dev_dbg_init(struct nbd_device *nbd) |
| { |
| return 0; |
| } |
| |
| static void nbd_dev_dbg_close(struct nbd_device *nbd) |
| { |
| } |
| |
| static int nbd_dbg_init(void) |
| { |
| return 0; |
| } |
| |
| static void nbd_dbg_close(void) |
| { |
| } |
| |
| #endif |
| |
| static int nbd_init_request(struct blk_mq_tag_set *set, struct request *rq, |
| unsigned int hctx_idx, unsigned int numa_node) |
| { |
| struct nbd_cmd *cmd = blk_mq_rq_to_pdu(rq); |
| cmd->nbd = set->driver_data; |
| return 0; |
| } |
| |
| static const struct blk_mq_ops nbd_mq_ops = { |
| .queue_rq = nbd_queue_rq, |
| .complete = nbd_complete_rq, |
| .init_request = nbd_init_request, |
| .timeout = nbd_xmit_timeout, |
| }; |
| |
| static int nbd_dev_add(int index) |
| { |
| struct nbd_device *nbd; |
| struct gendisk *disk; |
| struct request_queue *q; |
| int err = -ENOMEM; |
| |
| nbd = kzalloc(sizeof(struct nbd_device), GFP_KERNEL); |
| if (!nbd) |
| goto out; |
| |
| disk = alloc_disk(1 << part_shift); |
| if (!disk) |
| goto out_free_nbd; |
| |
| if (index >= 0) { |
| err = idr_alloc(&nbd_index_idr, nbd, index, index + 1, |
| GFP_KERNEL); |
| if (err == -ENOSPC) |
| err = -EEXIST; |
| } else { |
| err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL); |
| if (err >= 0) |
| index = err; |
| } |
| 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; |
| nbd->tag_set.queue_depth = 128; |
| nbd->tag_set.numa_node = NUMA_NO_NODE; |
| nbd->tag_set.cmd_size = sizeof(struct nbd_cmd); |
| nbd->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | |
| BLK_MQ_F_SG_MERGE | BLK_MQ_F_BLOCKING; |
| nbd->tag_set.driver_data = nbd; |
| |
| err = blk_mq_alloc_tag_set(&nbd->tag_set); |
| if (err) |
| goto out_free_idr; |
| |
| q = blk_mq_init_queue(&nbd->tag_set); |
| if (IS_ERR(q)) { |
| err = PTR_ERR(q); |
| goto out_free_tags; |
| } |
| disk->queue = q; |
| |
| /* |
| * Tell the block layer that we are not a rotational device |
| */ |
| blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); |
| blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue); |
| disk->queue->limits.discard_granularity = 512; |
| blk_queue_max_discard_sectors(disk->queue, UINT_MAX); |
| blk_queue_max_segment_size(disk->queue, UINT_MAX); |
| blk_queue_max_segments(disk->queue, USHRT_MAX); |
| blk_queue_max_hw_sectors(disk->queue, 65536); |
| disk->queue->limits.max_sectors = 256; |
| |
| mutex_init(&nbd->config_lock); |
| refcount_set(&nbd->config_refs, 0); |
| refcount_set(&nbd->refs, 1); |
| INIT_LIST_HEAD(&nbd->list); |
| disk->major = NBD_MAJOR; |
| disk->first_minor = index << part_shift; |
| disk->fops = &nbd_fops; |
| disk->private_data = nbd; |
| sprintf(disk->disk_name, "nbd%d", index); |
| add_disk(disk); |
| nbd_total_devices++; |
| return index; |
| |
| out_free_tags: |
| blk_mq_free_tag_set(&nbd->tag_set); |
| out_free_idr: |
| idr_remove(&nbd_index_idr, index); |
| out_free_disk: |
| put_disk(disk); |
| out_free_nbd: |
| kfree(nbd); |
| out: |
| return err; |
| } |
| |
| 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}, |
| [NBD_ATTR_DEAD_CONN_TIMEOUT] = { .type = NLA_U64 }, |
| [NBD_ATTR_DEVICE_LIST] = { .type = NLA_NESTED}, |
| }; |
| |
| static struct nla_policy nbd_sock_policy[NBD_SOCK_MAX + 1] = { |
| [NBD_SOCK_FD] = { .type = NLA_U32 }, |
| }; |
| |
| /* We don't use this right now since we don't parse the incoming list, but we |
| * still want it here so userspace knows what to expect. |
| */ |
| static struct nla_policy __attribute__((unused)) |
| nbd_device_policy[NBD_DEVICE_ATTR_MAX + 1] = { |
| [NBD_DEVICE_INDEX] = { .type = NLA_U32 }, |
| [NBD_DEVICE_CONNECTED] = { .type = NLA_U8 }, |
| }; |
| |
| 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; |
| bool put_dev = false; |
| |
| 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 new_index; |
| } |
| nbd = idr_find(&nbd_index_idr, new_index); |
| } |
| } else { |
| nbd = idr_find(&nbd_index_idr, index); |
| if (!nbd) { |
| ret = nbd_dev_add(index); |
| if (ret < 0) { |
| mutex_unlock(&nbd_index_mutex); |
| printk(KERN_ERR "nbd: failed to add new device\n"); |
| return ret; |
| } |
| nbd = idr_find(&nbd_index_idr, index); |
| } |
| } |
| if (!nbd) { |
| printk(KERN_ERR "nbd: couldn't find device at index %d\n", |
| index); |
| mutex_unlock(&nbd_index_mutex); |
| return -EINVAL; |
| } |
| if (!refcount_inc_not_zero(&nbd->refs)) { |
| mutex_unlock(&nbd_index_mutex); |
| if (index == -1) |
| goto again; |
| printk(KERN_ERR "nbd: device at index %d is going down\n", |
| index); |
| return -EINVAL; |
| } |
| mutex_unlock(&nbd_index_mutex); |
| |
| mutex_lock(&nbd->config_lock); |
| if (refcount_read(&nbd->config_refs)) { |
| mutex_unlock(&nbd->config_lock); |
| nbd_put(nbd); |
| 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); |
| nbd_put(nbd); |
| return -EINVAL; |
| } |
| config = nbd->config = nbd_alloc_config(); |
| if (!nbd->config) { |
| mutex_unlock(&nbd->config_lock); |
| nbd_put(nbd); |
| 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_DEAD_CONN_TIMEOUT]) { |
| config->dead_conn_timeout = |
| nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]); |
| config->dead_conn_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_CLIENT_FLAGS]) { |
| u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]); |
| if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) { |
| set_bit(NBD_DESTROY_ON_DISCONNECT, |
| &config->runtime_flags); |
| put_dev = true; |
| } |
| } |
| |
| 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, info->extack); |
| 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); |
| if (put_dev) |
| nbd_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); |
| if (!nbd) { |
| mutex_unlock(&nbd_index_mutex); |
| printk(KERN_ERR "nbd: couldn't find device at index %d\n", |
| index); |
| 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", |
| index); |
| return -EINVAL; |
| } |
| mutex_unlock(&nbd_index_mutex); |
| if (!refcount_inc_not_zero(&nbd->config_refs)) { |
| nbd_put(nbd); |
| 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); |
| nbd_put(nbd); |
| 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; |
| bool put_dev = false; |
| |
| 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); |
| if (!nbd) { |
| mutex_unlock(&nbd_index_mutex); |
| printk(KERN_ERR "nbd: couldn't find a device at index %d\n", |
| index); |
| 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", |
| index); |
| return -EINVAL; |
| } |
| mutex_unlock(&nbd_index_mutex); |
| |
| if (!refcount_inc_not_zero(&nbd->config_refs)) { |
| dev_err(nbd_to_dev(nbd), |
| "not configured, cannot reconfigure\n"); |
| nbd_put(nbd); |
| 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_DEAD_CONN_TIMEOUT]) { |
| config->dead_conn_timeout = |
| nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]); |
| config->dead_conn_timeout *= HZ; |
| } |
| if (info->attrs[NBD_ATTR_CLIENT_FLAGS]) { |
| u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]); |
| if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) { |
| if (!test_and_set_bit(NBD_DESTROY_ON_DISCONNECT, |
| &config->runtime_flags)) |
| put_dev = true; |
| } else { |
| if (test_and_clear_bit(NBD_DESTROY_ON_DISCONNECT, |
| &config->runtime_flags)) |
| refcount_inc(&nbd->refs); |
| } |
| } |
| |
| 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, info->extack); |
| 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); |
| nbd_put(nbd); |
| if (put_dev) |
| nbd_put(nbd); |
| return ret; |
| } |
| |
| 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, |
| }, |
| { |
| .cmd = NBD_CMD_RECONFIGURE, |
| .policy = nbd_attr_policy, |
| .doit = nbd_genl_reconfigure, |
| }, |
| { |
| .cmd = NBD_CMD_STATUS, |
| .policy = nbd_attr_policy, |
| .doit = nbd_genl_status, |
| }, |
| }; |
| |
| static const struct genl_multicast_group nbd_mcast_grps[] = { |
| { .name = NBD_GENL_MCAST_GROUP_NAME, }, |
| }; |
| |
| 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, |
| .mcgrps = nbd_mcast_grps, |
| .n_mcgrps = ARRAY_SIZE(nbd_mcast_grps), |
| }; |
| |
| static int populate_nbd_status(struct nbd_device *nbd, struct sk_buff *reply) |
| { |
| struct nlattr *dev_opt; |
| u8 connected = 0; |
| int ret; |
| |
| /* This is a little racey, but for status it's ok. The |
| * reason we don't take a ref here is because we can't |
| * take a ref in the index == -1 case as we would need |
| * to put under the nbd_index_mutex, which could |
| * deadlock if we are configured to remove ourselves |
| * once we're disconnected. |
| */ |
| if (refcount_read(&nbd->config_refs)) |
| connected = 1; |
| dev_opt = nla_nest_start(reply, NBD_DEVICE_ITEM); |
| if (!dev_opt) |
| return -EMSGSIZE; |
| ret = nla_put_u32(reply, NBD_DEVICE_INDEX, nbd->index); |
| if (ret) |
| return -EMSGSIZE; |
| ret = nla_put_u8(reply, NBD_DEVICE_CONNECTED, |
| connected); |
| if (ret) |
| return -EMSGSIZE; |
| nla_nest_end(reply, dev_opt); |
| return 0; |
| } |
| |
| static int status_cb(int id, void *ptr, void *data) |
| { |
| struct nbd_device *nbd = ptr; |
| return populate_nbd_status(nbd, (struct sk_buff *)data); |
| } |
| |
| static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info) |
| { |
| struct nlattr *dev_list; |
| struct sk_buff *reply; |
| void *reply_head; |
| size_t msg_size; |
| int index = -1; |
| int ret = -ENOMEM; |
| |
| if (info->attrs[NBD_ATTR_INDEX]) |
| index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]); |
| |
| mutex_lock(&nbd_index_mutex); |
| |
| msg_size = nla_total_size(nla_attr_size(sizeof(u32)) + |
| nla_attr_size(sizeof(u8))); |
| msg_size *= (index == -1) ? nbd_total_devices : 1; |
| |
| reply = genlmsg_new(msg_size, GFP_KERNEL); |
| if (!reply) |
| goto out; |
| reply_head = genlmsg_put_reply(reply, info, &nbd_genl_family, 0, |
| NBD_CMD_STATUS); |
| if (!reply_head) { |
| nlmsg_free(reply); |
| goto out; |
| } |
| |
| dev_list = nla_nest_start(reply, NBD_ATTR_DEVICE_LIST); |
| if (index == -1) { |
| ret = idr_for_each(&nbd_index_idr, &status_cb, reply); |
| if (ret) { |
| nlmsg_free(reply); |
| goto out; |
| } |
| } else { |
| struct nbd_device *nbd; |
| nbd = idr_find(&nbd_index_idr, index); |
| if (nbd) { |
| ret = populate_nbd_status(nbd, reply); |
| if (ret) { |
| nlmsg_free(reply); |
| goto out; |
| } |
| } |
| } |
| nla_nest_end(reply, dev_list); |
| genlmsg_end(reply, reply_head); |
| genlmsg_reply(reply, info); |
| ret = 0; |
| out: |
| mutex_unlock(&nbd_index_mutex); |
| return ret; |
| } |
| |
| 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 void nbd_mcast_index(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(skb, 0, 0, &nbd_genl_family, 0, |
| NBD_CMD_LINK_DEAD); |
| 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_multicast(&nbd_genl_family, skb, 0, 0, GFP_KERNEL); |
| } |
| |
| static void nbd_dead_link_work(struct work_struct *work) |
| { |
| struct link_dead_args *args = container_of(work, struct link_dead_args, |
| work); |
| nbd_mcast_index(args->index); |
| kfree(args); |
| } |
| |
| static int __init nbd_init(void) |
| { |
| int i; |
| |
| BUILD_BUG_ON(sizeof(struct nbd_request) != 28); |
| |
| if (max_part < 0) { |
| printk(KERN_ERR "nbd: max_part must be >= 0\n"); |
| return -EINVAL; |
| } |
| |
| part_shift = 0; |
| if (max_part > 0) { |
| part_shift = fls(max_part); |
| |
| /* |
| * Adjust max_part according to part_shift as it is exported |
| * to user space so that user can know the max number of |
| * partition kernel should be able to manage. |
| * |
| * Note that -1 is required because partition 0 is reserved |
| * for the whole disk. |
| */ |
| max_part = (1UL << part_shift) - 1; |
| } |
| |
| if ((1UL << part_shift) > DISK_MAX_PARTS) |
| return -EINVAL; |
| |
| if (nbds_max > 1UL << (MINORBITS - part_shift)) |
| return -EINVAL; |
| recv_workqueue = alloc_workqueue("knbd-recv", |
| WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); |
| if (!recv_workqueue) |
| return -ENOMEM; |
| |
| if (register_blkdev(NBD_MAJOR, "nbd")) { |
| destroy_workqueue(recv_workqueue); |
| 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); |
| for (i = 0; i < nbds_max; i++) |
| nbd_dev_add(i); |
| mutex_unlock(&nbd_index_mutex); |
| return 0; |
| } |
| |
| static int nbd_exit_cb(int id, void *ptr, void *data) |
| { |
| struct list_head *list = (struct list_head *)data; |
| struct nbd_device *nbd = ptr; |
| |
| list_add_tail(&nbd->list, list); |
| return 0; |
| } |
| |
| static void __exit nbd_cleanup(void) |
| { |
| struct nbd_device *nbd; |
| LIST_HEAD(del_list); |
| |
| nbd_dbg_close(); |
| |
| mutex_lock(&nbd_index_mutex); |
| idr_for_each(&nbd_index_idr, &nbd_exit_cb, &del_list); |
| mutex_unlock(&nbd_index_mutex); |
| |
| while (!list_empty(&del_list)) { |
| nbd = list_first_entry(&del_list, struct nbd_device, list); |
| list_del_init(&nbd->list); |
| if (refcount_read(&nbd->refs) != 1) |
| printk(KERN_ERR "nbd: possibly leaking a device\n"); |
| nbd_put(nbd); |
| } |
| |
| idr_destroy(&nbd_index_idr); |
| genl_unregister_family(&nbd_genl_family); |
| destroy_workqueue(recv_workqueue); |
| unregister_blkdev(NBD_MAJOR, "nbd"); |
| } |
| |
| module_init(nbd_init); |
| module_exit(nbd_cleanup); |
| |
| MODULE_DESCRIPTION("Network Block Device"); |
| MODULE_LICENSE("GPL"); |
| |
| module_param(nbds_max, int, 0444); |
| MODULE_PARM_DESC(nbds_max, "number of network block devices to initialize (default: 16)"); |
| module_param(max_part, int, 0444); |
| MODULE_PARM_DESC(max_part, "number of partitions per device (default: 16)"); |