diff options
Diffstat (limited to 'drivers/block/nbd.c')
| -rw-r--r-- | drivers/block/nbd.c | 362 |
1 files changed, 290 insertions, 72 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index f169faf9838a..293495a75d3d 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -33,6 +33,7 @@ #include <linux/net.h> #include <linux/kthread.h> #include <linux/types.h> +#include <linux/debugfs.h> #include <asm/uaccess.h> #include <asm/types.h> @@ -40,8 +41,7 @@ #include <linux/nbd.h> struct nbd_device { - int flags; - int harderror; /* Code of hard error */ + u32 flags; struct socket * sock; /* If == NULL, device is not ready, yet */ int magic; @@ -56,11 +56,24 @@ struct nbd_device { struct gendisk *disk; int blksize; loff_t bytesize; - pid_t pid; /* pid of nbd-client, if attached */ int xmit_timeout; - int disconnect; /* a disconnect has been requested by user */ + bool disconnect; /* a disconnect has been requested by user */ + + struct timer_list timeout_timer; + struct task_struct *task_recv; + struct task_struct *task_send; + +#if IS_ENABLED(CONFIG_DEBUG_FS) + struct dentry *dbg_dir; +#endif }; +#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; @@ -113,26 +126,36 @@ static void nbd_end_request(struct nbd_device *nbd, struct request *req) /* * Forcibly shutdown the socket causing all listeners to error */ -static void sock_shutdown(struct nbd_device *nbd, int lock) +static void sock_shutdown(struct nbd_device *nbd) { - if (lock) - mutex_lock(&nbd->tx_lock); - if (nbd->sock) { - dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n"); - kernel_sock_shutdown(nbd->sock, SHUT_RDWR); - nbd->sock = NULL; - } - if (lock) - mutex_unlock(&nbd->tx_lock); + if (!nbd->sock) + return; + + dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n"); + kernel_sock_shutdown(nbd->sock, SHUT_RDWR); + nbd->sock = NULL; + del_timer_sync(&nbd->timeout_timer); } static void nbd_xmit_timeout(unsigned long arg) { - struct task_struct *task = (struct task_struct *)arg; + struct nbd_device *nbd = (struct nbd_device *)arg; + struct task_struct *task; + + if (list_empty(&nbd->queue_head)) + return; + + nbd->disconnect = true; + + task = READ_ONCE(nbd->task_recv); + if (task) + force_sig(SIGKILL, task); - printk(KERN_WARNING "nbd: killing hung xmit (%s, pid: %d)\n", - task->comm, task->pid); - force_sig(SIGKILL, task); + task = READ_ONCE(nbd->task_send); + if (task) + force_sig(SIGKILL, nbd->task_send); + + dev_err(nbd_to_dev(nbd), "Connection timed out, killed receiver and sender, shutting down connection\n"); } /* @@ -171,33 +194,12 @@ static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size, msg.msg_controllen = 0; msg.msg_flags = msg_flags | MSG_NOSIGNAL; - if (send) { - struct timer_list ti; - - if (nbd->xmit_timeout) { - init_timer(&ti); - ti.function = nbd_xmit_timeout; - ti.data = (unsigned long)current; - ti.expires = jiffies + nbd->xmit_timeout; - add_timer(&ti); - } + if (send) result = kernel_sendmsg(sock, &msg, &iov, 1, size); - if (nbd->xmit_timeout) - del_timer_sync(&ti); - } else + else result = kernel_recvmsg(sock, &msg, &iov, 1, size, msg.msg_flags); - if (signal_pending(current)) { - siginfo_t info; - printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", - task_pid_nr(current), current->comm, - dequeue_signal_lock(current, ¤t->blocked, &info)); - result = -EINTR; - sock_shutdown(nbd, !send); - break; - } - if (result <= 0) { if (result == 0) result = -EPIPE; /* short read */ @@ -210,6 +212,9 @@ static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size, sigprocmask(SIG_SETMASK, &oldset, NULL); tsk_restore_flags(current, pflags, PF_MEMALLOC); + if (!send && nbd->xmit_timeout) + mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout); + return result; } @@ -333,26 +338,24 @@ static struct request *nbd_read_stat(struct nbd_device *nbd) if (result <= 0) { dev_err(disk_to_dev(nbd->disk), "Receive control failed (result %d)\n", result); - goto harderror; + 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)); - result = -EPROTO; - goto harderror; + return ERR_PTR(-EPROTO); } req = nbd_find_request(nbd, *(struct request **)reply.handle); if (IS_ERR(req)) { result = PTR_ERR(req); if (result != -ENOENT) - goto harderror; + return ERR_PTR(result); dev_err(disk_to_dev(nbd->disk), "Unexpected reply (%p)\n", reply.handle); - result = -EBADR; - goto harderror; + return ERR_PTR(-EBADR); } if (ntohl(reply.error)) { @@ -380,18 +383,15 @@ static struct request *nbd_read_stat(struct nbd_device *nbd) } } return req; -harderror: - nbd->harderror = result; - return NULL; } 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, "%ld\n", - (long) ((struct nbd_device *)disk->private_data)->pid); + return sprintf(buf, "%d\n", task_pid_nr(nbd->task_recv)); } static struct device_attribute pid_attr = { @@ -399,7 +399,7 @@ static struct device_attribute pid_attr = { .show = pid_show, }; -static int nbd_do_it(struct nbd_device *nbd) +static int nbd_thread_recv(struct nbd_device *nbd) { struct request *req; int ret; @@ -407,20 +407,43 @@ static int nbd_do_it(struct nbd_device *nbd) BUG_ON(nbd->magic != NBD_MAGIC); sk_set_memalloc(nbd->sock->sk); - nbd->pid = task_pid_nr(current); + + nbd->task_recv = current; + ret = device_create_file(disk_to_dev(nbd->disk), &pid_attr); if (ret) { dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n"); - nbd->pid = 0; + nbd->task_recv = NULL; return ret; } - while ((req = nbd_read_stat(nbd)) != NULL) + while (1) { + req = nbd_read_stat(nbd); + if (IS_ERR(req)) { + ret = PTR_ERR(req); + break; + } + nbd_end_request(nbd, req); + } device_remove_file(disk_to_dev(nbd->disk), &pid_attr); - nbd->pid = 0; - return 0; + + nbd->task_recv = NULL; + + if (signal_pending(current)) { + siginfo_t info; + + ret = dequeue_signal_lock(current, ¤t->blocked, &info); + dev_warn(nbd_to_dev(nbd), "pid %d, %s, got signal %d\n", + task_pid_nr(current), current->comm, ret); + mutex_lock(&nbd->tx_lock); + sock_shutdown(nbd); + mutex_unlock(&nbd->tx_lock); + ret = -ETIMEDOUT; + } + + return ret; } static void nbd_clear_que(struct nbd_device *nbd) @@ -455,6 +478,7 @@ static void nbd_clear_que(struct nbd_device *nbd) req->errors++; nbd_end_request(nbd, req); } + dev_dbg(disk_to_dev(nbd->disk), "queue cleared\n"); } @@ -482,6 +506,9 @@ static void nbd_handle_req(struct nbd_device *nbd, struct request *req) nbd->active_req = req; + if (nbd->xmit_timeout && list_empty_careful(&nbd->queue_head)) + mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout); + if (nbd_send_req(nbd, req) != 0) { dev_err(disk_to_dev(nbd->disk), "Request send failed\n"); req->errors++; @@ -503,11 +530,13 @@ error_out: nbd_end_request(nbd, req); } -static int nbd_thread(void *data) +static int nbd_thread_send(void *data) { struct nbd_device *nbd = data; struct request *req; + nbd->task_send = current; + set_user_nice(current, MIN_NICE); while (!kthread_should_stop() || !list_empty(&nbd->waiting_queue)) { /* wait for something to do */ @@ -515,6 +544,20 @@ static int nbd_thread(void *data) kthread_should_stop() || !list_empty(&nbd->waiting_queue)); + if (signal_pending(current)) { + siginfo_t info; + int ret; + + ret = dequeue_signal_lock(current, ¤t->blocked, + &info); + dev_warn(nbd_to_dev(nbd), "pid %d, %s, got signal %d\n", + task_pid_nr(current), current->comm, ret); + mutex_lock(&nbd->tx_lock); + sock_shutdown(nbd); + mutex_unlock(&nbd->tx_lock); + break; + } + /* extract request */ if (list_empty(&nbd->waiting_queue)) continue; @@ -528,6 +571,9 @@ static int nbd_thread(void *data) /* handle request */ nbd_handle_req(nbd, req); } + + nbd->task_send = NULL; + return 0; } @@ -538,7 +584,7 @@ static int nbd_thread(void *data) * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } */ -static void do_nbd_request(struct request_queue *q) +static void nbd_request_handler(struct request_queue *q) __releases(q->queue_lock) __acquires(q->queue_lock) { struct request *req; @@ -574,6 +620,9 @@ static void do_nbd_request(struct request_queue *q) } } +static int nbd_dev_dbg_init(struct nbd_device *nbd); +static void nbd_dev_dbg_close(struct nbd_device *nbd); + /* Must be called with tx_lock held */ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, @@ -597,7 +646,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, if (!nbd->sock) return -EINVAL; - nbd->disconnect = 1; + nbd->disconnect = true; nbd_send_req(nbd, &sreq); return 0; @@ -625,7 +674,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, nbd->sock = sock; if (max_part > 0) bdev->bd_invalidated = 1; - nbd->disconnect = 0; /* we're connected now */ + nbd->disconnect = false; /* we're connected now */ return 0; } return -EINVAL; @@ -648,6 +697,12 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, case NBD_SET_TIMEOUT: nbd->xmit_timeout = arg * HZ; + if (arg) + mod_timer(&nbd->timeout_timer, + jiffies + nbd->xmit_timeout); + else + del_timer_sync(&nbd->timeout_timer); + return 0; case NBD_SET_FLAGS: @@ -666,7 +721,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, struct socket *sock; int error; - if (nbd->pid) + if (nbd->task_recv) return -EBUSY; if (!nbd->sock) return -EINVAL; @@ -683,24 +738,24 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, else blk_queue_flush(nbd->disk->queue, 0); - thread = kthread_run(nbd_thread, nbd, "%s", - nbd->disk->disk_name); + thread = kthread_run(nbd_thread_send, nbd, "%s", + nbd_name(nbd)); if (IS_ERR(thread)) { mutex_lock(&nbd->tx_lock); return PTR_ERR(thread); } - error = nbd_do_it(nbd); + nbd_dev_dbg_init(nbd); + error = nbd_thread_recv(nbd); + nbd_dev_dbg_close(nbd); kthread_stop(thread); mutex_lock(&nbd->tx_lock); - if (error) - return error; - sock_shutdown(nbd, 0); + + sock_shutdown(nbd); sock = nbd->sock; nbd->sock = NULL; nbd_clear_que(nbd); - dev_warn(disk_to_dev(nbd->disk), "queue cleared\n"); kill_bdev(bdev); queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue); set_device_ro(bdev, false); @@ -714,7 +769,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, blkdev_reread_part(bdev); if (nbd->disconnect) /* user requested, ignore socket errors */ return 0; - return nbd->harderror; + return error; } case NBD_CLEAR_QUE: @@ -758,6 +813,161 @@ static const struct block_device_operations nbd_fops = .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)); + if (nbd->task_send) + seq_printf(s, "send: %d\n", task_pid_nr(nbd->task_send)); + + 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->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_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 dentry *f; + + dir = debugfs_create_dir(nbd_name(nbd), nbd_dbg_dir); + if (IS_ERR_OR_NULL(dir)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs dir for '%s' (%ld)\n", + nbd_name(nbd), PTR_ERR(dir)); + return PTR_ERR(dir); + } + nbd->dbg_dir = dir; + + f = debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'tasks', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + f = debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'size_bytes', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + f = debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'timeout', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + f = debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'blocksize', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + f = debugfs_create_file("flags", 0444, dir, &nbd, &nbd_dbg_flags_ops); + if (IS_ERR_OR_NULL(f)) { + dev_err(nbd_to_dev(nbd), "Failed to create debugfs file 'flags', %ld\n", + PTR_ERR(f)); + return PTR_ERR(f); + } + + return 0; +} + +static void nbd_dev_dbg_close(struct nbd_device *nbd) +{ + debugfs_remove_recursive(nbd->dbg_dir); +} + +static int nbd_dbg_init(void) +{ + struct dentry *dbg_dir; + + dbg_dir = debugfs_create_dir("nbd", NULL); + if (IS_ERR(dbg_dir)) + return PTR_ERR(dbg_dir); + + 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 + /* * And here should be modules and kernel interface * (Just smiley confuses emacs :-) @@ -811,7 +1021,7 @@ static int __init nbd_init(void) * every gendisk to have its very own request_queue struct. * These structs are big so we dynamically allocate them. */ - disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); + disk->queue = blk_init_queue(nbd_request_handler, &nbd_lock); if (!disk->queue) { put_disk(disk); goto out; @@ -835,6 +1045,8 @@ static int __init nbd_init(void) printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); + nbd_dbg_init(); + for (i = 0; i < nbds_max; i++) { struct gendisk *disk = nbd_dev[i].disk; nbd_dev[i].magic = NBD_MAGIC; @@ -842,6 +1054,9 @@ static int __init nbd_init(void) spin_lock_init(&nbd_dev[i].queue_lock); INIT_LIST_HEAD(&nbd_dev[i].queue_head); mutex_init(&nbd_dev[i].tx_lock); + init_timer(&nbd_dev[i].timeout_timer); + nbd_dev[i].timeout_timer.function = nbd_xmit_timeout; + nbd_dev[i].timeout_timer.data = (unsigned long)&nbd_dev[i]; init_waitqueue_head(&nbd_dev[i].active_wq); init_waitqueue_head(&nbd_dev[i].waiting_wq); nbd_dev[i].blksize = 1024; @@ -868,6 +1083,9 @@ out: static void __exit nbd_cleanup(void) { int i; + + nbd_dbg_close(); + for (i = 0; i < nbds_max; i++) { struct gendisk *disk = nbd_dev[i].disk; nbd_dev[i].magic = 0; |