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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.c362
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, &current->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, &current->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, &current->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;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-06 07:53:08 +0000