nbd: Remove 'harderror' and propagate error properly

Instead of a variable 'harderror' we can simply try to correctly
propagate errors to the userspace.

This patch removes the harderror variable and passes errors through
error pointers and nbd_do_it back to the userspace.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 137b45f..4b317ae 100644 (file)
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -41,7 +41,6 @@
 
 struct nbd_device {
        int flags;
-       int harderror;          /* Code of hard error                   */
        struct socket * sock;   /* If == NULL, device is not ready, yet */
        int magic;
 
@@ -329,26 +328,24 @@ 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)) {
@@ -376,9 +373,6 @@ 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,
@@ -413,8 +407,15 @@ static int nbd_do_it(struct nbd_device *nbd)
 
        nbd->task_recv = current;
 
-       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);
+       }
 
        nbd->task_recv = NULL;
 
@@ -734,8 +735,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
                kthread_stop(thread);
 
                mutex_lock(&nbd->tx_lock);
-               if (error)
-                       return error;
+
                sock_shutdown(nbd);
                sock = nbd->sock;
                nbd->sock = NULL;
@@ -754,7 +754,7 @@ 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: