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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.c127
1 files changed, 80 insertions, 47 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index e21d2ded732b..a8e3815295fe 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -108,6 +108,7 @@ struct nbd_device {
struct nbd_config *config;
struct mutex config_lock;
struct gendisk *disk;
+ struct workqueue_struct *recv_workq;
struct list_head list;
struct task_struct *task_recv;
@@ -121,6 +122,7 @@ struct nbd_cmd {
struct mutex lock;
int index;
int cookie;
+ int retries;
blk_status_t status;
unsigned long flags;
u32 cmd_cookie;
@@ -138,7 +140,6 @@ static struct dentry *nbd_dbg_dir;
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);
@@ -344,6 +345,22 @@ static void sock_shutdown(struct nbd_device *nbd)
dev_warn(disk_to_dev(nbd->disk), "shutting down sockets\n");
}
+static u32 req_to_nbd_cmd_type(struct request *req)
+{
+ switch (req_op(req)) {
+ case REQ_OP_DISCARD:
+ return NBD_CMD_TRIM;
+ case REQ_OP_FLUSH:
+ return NBD_CMD_FLUSH;
+ case REQ_OP_WRITE:
+ return NBD_CMD_WRITE;
+ case REQ_OP_READ:
+ return NBD_CMD_READ;
+ default:
+ return U32_MAX;
+ }
+}
+
static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
bool reserved)
{
@@ -357,8 +374,10 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
}
config = nbd->config;
- if (!mutex_trylock(&cmd->lock))
+ if (!mutex_trylock(&cmd->lock)) {
+ nbd_config_put(nbd);
return BLK_EH_RESET_TIMER;
+ }
if (config->num_connections > 1) {
dev_err_ratelimited(nbd_to_dev(nbd),
@@ -389,10 +408,25 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
nbd_config_put(nbd);
return BLK_EH_DONE;
}
- } else {
- dev_err_ratelimited(nbd_to_dev(nbd),
- "Connection timed out\n");
}
+
+ if (!nbd->tag_set.timeout) {
+ /*
+ * Userspace sets timeout=0 to disable socket disconnection,
+ * so just warn and reset the timer.
+ */
+ cmd->retries++;
+ dev_info(nbd_to_dev(nbd), "Possible stuck request %p: control (%s@%llu,%uB). Runtime %u seconds\n",
+ req, nbdcmd_to_ascii(req_to_nbd_cmd_type(req)),
+ (unsigned long long)blk_rq_pos(req) << 9,
+ blk_rq_bytes(req), (req->timeout / HZ) * cmd->retries);
+
+ mutex_unlock(&cmd->lock);
+ nbd_config_put(nbd);
+ return BLK_EH_RESET_TIMER;
+ }
+
+ dev_err_ratelimited(nbd_to_dev(nbd), "Connection timed out\n");
set_bit(NBD_TIMEDOUT, &config->runtime_flags);
cmd->status = BLK_STS_IOERR;
mutex_unlock(&cmd->lock);
@@ -480,22 +514,9 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
iov_iter_kvec(&from, WRITE, &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:
+ type = req_to_nbd_cmd_type(req);
+ if (type == U32_MAX)
return -EIO;
- }
if (rq_data_dir(req) == WRITE &&
(config->flags & NBD_FLAG_READ_ONLY)) {
@@ -526,6 +547,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index)
}
cmd->index = index;
cmd->cookie = nsock->cookie;
+ cmd->retries = 0;
request.type = htonl(type | nbd_cmd_flags);
if (type != NBD_CMD_FLUSH) {
request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
@@ -1036,7 +1058,7 @@ static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg)
/* 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);
+ queue_work(nbd->recv_workq, &args->work);
atomic_inc(&config->live_connections);
wake_up(&config->conn_wait);
@@ -1137,6 +1159,10 @@ static void nbd_config_put(struct nbd_device *nbd)
kfree(nbd->config);
nbd->config = NULL;
+ if (nbd->recv_workq)
+ destroy_workqueue(nbd->recv_workq);
+ nbd->recv_workq = NULL;
+
nbd->tag_set.timeout = 0;
nbd->disk->queue->limits.discard_granularity = 0;
nbd->disk->queue->limits.discard_alignment = 0;
@@ -1165,6 +1191,14 @@ static int nbd_start_device(struct nbd_device *nbd)
return -EINVAL;
}
+ nbd->recv_workq = alloc_workqueue("knbd%d-recv",
+ WQ_MEM_RECLAIM | WQ_HIGHPRI |
+ WQ_UNBOUND, 0, nbd->index);
+ if (!nbd->recv_workq) {
+ dev_err(disk_to_dev(nbd->disk), "Could not allocate knbd recv work queue.\n");
+ return -ENOMEM;
+ }
+
blk_mq_update_nr_hw_queues(&nbd->tag_set, config->num_connections);
nbd->task_recv = current;
@@ -1195,7 +1229,7 @@ static int nbd_start_device(struct nbd_device *nbd)
INIT_WORK(&args->work, recv_work);
args->nbd = nbd;
args->index = i;
- queue_work(recv_workqueue, &args->work);
+ queue_work(nbd->recv_workq, &args->work);
}
nbd_size_update(nbd);
return error;
@@ -1215,8 +1249,10 @@ static int nbd_start_device_ioctl(struct nbd_device *nbd, struct block_device *b
mutex_unlock(&nbd->config_lock);
ret = wait_event_interruptible(config->recv_wq,
atomic_read(&config->recv_threads) == 0);
- if (ret)
+ if (ret) {
sock_shutdown(nbd);
+ flush_workqueue(nbd->recv_workq);
+ }
mutex_lock(&nbd->config_lock);
nbd_bdev_reset(bdev);
/* user requested, ignore socket errors */
@@ -1246,6 +1282,13 @@ static bool nbd_is_valid_blksize(unsigned long blksize)
return true;
}
+static void nbd_set_cmd_timeout(struct nbd_device *nbd, u64 timeout)
+{
+ nbd->tag_set.timeout = timeout * HZ;
+ if (timeout)
+ blk_queue_rq_timeout(nbd->disk->queue, timeout * HZ);
+}
+
/* 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)
@@ -1276,10 +1319,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
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);
- }
+ nbd_set_cmd_timeout(nbd, arg);
return 0;
case NBD_SET_FLAGS:
@@ -1799,11 +1839,9 @@ again:
if (ret)
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_TIMEOUT])
+ nbd_set_cmd_timeout(nbd,
+ nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]));
if (info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]) {
config->dead_conn_timeout =
nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]);
@@ -1875,6 +1913,12 @@ static void nbd_disconnect_and_put(struct nbd_device *nbd)
nbd_disconnect(nbd);
nbd_clear_sock(nbd);
mutex_unlock(&nbd->config_lock);
+ /*
+ * Make sure recv thread has finished, so it does not drop the last
+ * config ref and try to destroy the workqueue from inside the work
+ * queue.
+ */
+ flush_workqueue(nbd->recv_workq);
if (test_and_clear_bit(NBD_HAS_CONFIG_REF,
&nbd->config->runtime_flags))
nbd_config_put(nbd);
@@ -1971,11 +2015,9 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
if (ret)
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_TIMEOUT])
+ nbd_set_cmd_timeout(nbd,
+ nla_get_u64(info->attrs[NBD_ATTR_TIMEOUT]));
if (info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]) {
config->dead_conn_timeout =
nla_get_u64(info->attrs[NBD_ATTR_DEAD_CONN_TIMEOUT]);
@@ -2261,20 +2303,12 @@ static int __init nbd_init(void)
if (nbds_max > 1UL << (MINORBITS - part_shift))
return -EINVAL;
- recv_workqueue = alloc_workqueue("knbd-recv",
- WQ_MEM_RECLAIM | WQ_HIGHPRI |
- WQ_UNBOUND, 0);
- if (!recv_workqueue)
- return -ENOMEM;
- if (register_blkdev(NBD_MAJOR, "nbd")) {
- destroy_workqueue(recv_workqueue);
+ if (register_blkdev(NBD_MAJOR, "nbd"))
return -EIO;
- }
if (genl_register_family(&nbd_genl_family)) {
unregister_blkdev(NBD_MAJOR, "nbd");
- destroy_workqueue(recv_workqueue);
return -EINVAL;
}
nbd_dbg_init();
@@ -2316,7 +2350,6 @@ static void __exit nbd_cleanup(void)
idr_destroy(&nbd_index_idr);
genl_unregister_family(&nbd_genl_family);
- destroy_workqueue(recv_workqueue);
unregister_blkdev(NBD_MAJOR, "nbd");
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.