nbd: allow block mq to deal with timeouts
authorJosef Bacik <jbacik@fb.com>
Thu, 8 Sep 2016 19:33:40 +0000 (12:33 -0700)
committerJens Axboe <axboe@fb.com>
Thu, 8 Sep 2016 20:01:37 +0000 (14:01 -0600)
Instead of rolling our own timer, just utilize the blk mq req timeout and do the
disconnect if any of our commands timeout.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
drivers/block/nbd.c

index cf855a1b3729ba32200df67b73d37c552fef88d3..4c6dd1a85eade5affc3baff9a2470b7e3d312b45 100644 (file)
@@ -50,16 +50,13 @@ struct nbd_device {
        struct socket * sock;   /* If == NULL, device is not ready, yet */
        int magic;
 
-       atomic_t outstanding_cmds;
        struct blk_mq_tag_set tag_set;
 
        struct mutex tx_lock;
        struct gendisk *disk;
        int blksize;
        loff_t bytesize;
-       int xmit_timeout;
 
-       struct timer_list timeout_timer;
        /* protects initialization and shutdown of the socket */
        spinlock_t sock_lock;
        struct task_struct *task_recv;
@@ -154,7 +151,6 @@ static void nbd_end_request(struct nbd_cmd *cmd)
        dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", cmd,
                error ? "failed" : "done");
 
-       atomic_dec(&nbd->outstanding_cmds);
        blk_mq_complete_request(req, error);
 }
 
@@ -165,7 +161,7 @@ static void sock_shutdown(struct nbd_device *nbd)
 {
        struct socket *sock;
 
-       spin_lock_irq(&nbd->sock_lock);
+       spin_lock(&nbd->sock_lock);
 
        if (!nbd->sock) {
                spin_unlock_irq(&nbd->sock_lock);
@@ -175,24 +171,20 @@ static void sock_shutdown(struct nbd_device *nbd)
        sock = nbd->sock;
        dev_warn(disk_to_dev(nbd->disk), "shutting down socket\n");
        nbd->sock = NULL;
-       spin_unlock_irq(&nbd->sock_lock);
+       spin_unlock(&nbd->sock_lock);
 
        kernel_sock_shutdown(sock, SHUT_RDWR);
        sockfd_put(sock);
-
-       del_timer(&nbd->timeout_timer);
 }
 
-static void nbd_xmit_timeout(unsigned long arg)
+static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
+                                                bool reserved)
 {
-       struct nbd_device *nbd = (struct nbd_device *)arg;
+       struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
+       struct nbd_device *nbd = cmd->nbd;
        struct socket *sock = NULL;
-       unsigned long flags;
-
-       if (!atomic_read(&nbd->outstanding_cmds))
-               return;
 
-       spin_lock_irqsave(&nbd->sock_lock, flags);
+       spin_lock(&nbd->sock_lock);
 
        set_bit(NBD_TIMEDOUT, &nbd->runtime_flags);
 
@@ -201,13 +193,15 @@ static void nbd_xmit_timeout(unsigned long arg)
                get_file(sock->file);
        }
 
-       spin_unlock_irqrestore(&nbd->sock_lock, flags);
+       spin_unlock(&nbd->sock_lock);
        if (sock) {
                kernel_sock_shutdown(sock, SHUT_RDWR);
                sockfd_put(sock);
        }
 
+       req->errors++;
        dev_err(nbd_to_dev(nbd), "Connection timed out, shutting down connection\n");
+       return BLK_EH_HANDLED;
 }
 
 /*
@@ -257,9 +251,6 @@ static int sock_xmit(struct nbd_device *nbd, int send, void *buf, int size,
 
        tsk_restore_flags(current, pflags, PF_MEMALLOC);
 
-       if (!send && nbd->xmit_timeout)
-               mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout);
-
        return result;
 }
 
@@ -512,10 +503,6 @@ static void nbd_handle_cmd(struct nbd_cmd *cmd)
                goto error_out;
        }
 
-       if (nbd->xmit_timeout && !atomic_read(&nbd->outstanding_cmds))
-               mod_timer(&nbd->timeout_timer, jiffies + nbd->xmit_timeout);
-
-       atomic_inc(&nbd->outstanding_cmds);
        if (nbd_send_cmd(nbd, cmd) != 0) {
                dev_err(disk_to_dev(nbd->disk), "Request send failed\n");
                req->errors++;
@@ -569,9 +556,8 @@ static void nbd_reset(struct nbd_device *nbd)
        nbd->bytesize = 0;
        set_capacity(nbd->disk, 0);
        nbd->flags = 0;
-       nbd->xmit_timeout = 0;
+       nbd->tag_set.timeout = 0;
        queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);
-       del_timer_sync(&nbd->timeout_timer);
 }
 
 static void nbd_bdev_reset(struct block_device *bdev)
@@ -668,13 +654,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
                return nbd_size_set(nbd, bdev, nbd->blksize, arg);
 
        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);
-
+               nbd->tag_set.timeout = arg * HZ;
                return 0;
 
        case NBD_SET_FLAGS:
@@ -836,7 +816,7 @@ static int nbd_dev_dbg_init(struct nbd_device *nbd)
 
        debugfs_create_file("tasks", 0444, dir, nbd, &nbd_dbg_tasks_ops);
        debugfs_create_u64("size_bytes", 0444, dir, &nbd->bytesize);
-       debugfs_create_u32("timeout", 0444, dir, &nbd->xmit_timeout);
+       debugfs_create_u32("timeout", 0444, dir, &nbd->tag_set.timeout);
        debugfs_create_u32("blocksize", 0444, dir, &nbd->blksize);
        debugfs_create_file("flags", 0444, dir, nbd, &nbd_dbg_flags_ops);
 
@@ -903,6 +883,7 @@ static struct blk_mq_ops nbd_mq_ops = {
        .queue_rq       = nbd_queue_rq,
        .map_queue      = blk_mq_map_queue,
        .init_request   = nbd_init_request,
+       .timeout        = nbd_xmit_timeout,
 };
 
 /*
@@ -1007,10 +988,6 @@ static int __init nbd_init(void)
                nbd_dev[i].magic = NBD_MAGIC;
                spin_lock_init(&nbd_dev[i].sock_lock);
                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];
-               atomic_set(&nbd_dev[i].outstanding_cmds, 0);
                disk->major = NBD_MAJOR;
                disk->first_minor = i << part_shift;
                disk->fops = &nbd_fops;