[PATCH] NBD rmmod oops fix

From: Paul Clements <Paul.Clements@SteelEye.com>

Fix a module unload oops, as well as fix some return codes (so nbd-client
can exit with the proper error code, rather than 0, when an error occurs).

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index a88005e7779ea18833cd4fcdef9415309ef4f0fe..b78dd162f0af02e01245f76adffa694dabff2716 100644 (file)
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -221,6 +221,8 @@ static int sock_xmit(struct socket *sock, int send, void *buf, int size,
                        printk(KERN_ERR "nbd: %s - sock=%p at buf=%p, size=%d returned %d.\n",
                               send? "send": "receive", sock, buf, size, result);
 #endif
+                       if (result == 0)
+                               result = -EPIPE; /* short read */
                        break;
                }
                size -= result;
@@ -309,7 +311,7 @@ void nbd_send_req(struct nbd_device *lo, struct request *req)
        up(&lo->tx_lock);
        return;
 
-      error_out:
+error_out:
        up(&lo->tx_lock);
        req->errors++;
 }
@@ -358,23 +360,22 @@ struct request *nbd_read_stat(struct nbd_device *lo)
        if (result <= 0) {
                printk(KERN_ERR "%s: Receive control failed (result %d)\n",
                                lo->disk->disk_name, result);
-               lo->harderror = result;
-               return NULL;
+               goto harderror;
        }
        req = nbd_find_request(lo, reply.handle);
        if (req == NULL) {
                printk(KERN_ERR "%s: Unexpected reply (%p)\n",
                                lo->disk->disk_name, reply.handle);
-               lo->harderror = result;
-               return NULL;
+               result = -EBADR;
+               goto harderror;
        }
 
        if (ntohl(reply.magic) != NBD_REPLY_MAGIC) {
                printk(KERN_ERR "%s: Wrong magic (0x%lx)\n",
                                lo->disk->disk_name,
                                (unsigned long)ntohl(reply.magic));
-               lo->harderror = result;
-               return NULL;
+               result = -EPROTO;
+               goto harderror;
        }
        if (ntohl(reply.error)) {
                printk(KERN_ERR "%s: Other side returned error (%d)\n",
@@ -396,8 +397,7 @@ struct request *nbd_read_stat(struct nbd_device *lo)
                                        printk(KERN_ERR "%s: Receive data failed (result %d)\n",
                                                        lo->disk->disk_name,
                                                        result);
-                                       lo->harderror = result;
-                                       return NULL;
+                                       goto harderror;
                                }
                                dprintk(DBG_RX, "%s: request %p: got %d bytes data\n",
                                        lo->disk->disk_name, req, bvec->bv_len);
@@ -405,6 +405,9 @@ struct request *nbd_read_stat(struct nbd_device *lo)
                }
        }
        return req;
+harderror:
+       lo->harderror = result;
+       return NULL;
 }
 
 void nbd_do_it(struct nbd_device *lo)
@@ -416,8 +419,6 @@ void nbd_do_it(struct nbd_device *lo)
 #endif
        while ((req = nbd_read_stat(lo)) != NULL)
                nbd_end_request(req);
-       printk(KERN_NOTICE "%s: req should never be null\n",
-                       lo->disk->disk_name);
        return;
 }
 
@@ -751,8 +752,7 @@ static int __init nbd_init(void)
        return 0;
 out:
        while (i--) {
-               if (nbd_dev[i].disk->queue)
-                       blk_cleanup_queue(nbd_dev[i].disk->queue);
+               blk_cleanup_queue(nbd_dev[i].disk->queue);
                put_disk(nbd_dev[i].disk);
        }
        return err;
@@ -764,9 +764,8 @@ static void __exit nbd_cleanup(void)
        for (i = 0; i < MAX_NBD; i++) {
                struct gendisk *disk = nbd_dev[i].disk;
                if (disk) {
-                       if (disk->queue)
-                               blk_cleanup_queue(disk->queue);
                        del_gendisk(disk);
+                       blk_cleanup_queue(disk->queue);
                        put_disk(disk);
                }
        }