[SCSI] sd: fix bug in SCSI async probing

The async split up of probing in sd.c created a potential failure case where
something goes wrong with device_add(), but which we don't recover properly.
Since, in general, asynchronous error handling is hard, move the device_add()
into the asynchronous path (it should be fast) and make sure all the deferred
processing cannot fail.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 84044233b637c71929bf22b665d15976096e5d63..d8e1d15101b73cf0614d08add504ce1ec5e6e99f 100644 (file)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1902,24 +1902,6 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
        index = sdkp->index;
        dev = &sdp->sdev_gendev;
 
-       if (!sdp->request_queue->rq_timeout) {
-               if (sdp->type != TYPE_MOD)
-                       blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
-               else
-                       blk_queue_rq_timeout(sdp->request_queue,
-                                            SD_MOD_TIMEOUT);
-       }
-
-       device_initialize(&sdkp->dev);
-       sdkp->dev.parent = &sdp->sdev_gendev;
-       sdkp->dev.class = &sd_disk_class;
-       dev_set_name(&sdkp->dev, dev_name(&sdp->sdev_gendev));
-
-       if (device_add(&sdkp->dev))
-               goto out_free_index;
-
-       get_device(&sdp->sdev_gendev);
-
        if (index < SD_MAX_DISKS) {
                gd->major = sd_major((index & 0xf0) >> 4);
                gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
@@ -1954,11 +1936,6 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
 
        sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
                  sdp->removable ? "removable " : "");
-
-       return;
-
- out_free_index:
-       ida_remove(&sd_index_ida, index);
 }
 
 /**
@@ -2026,6 +2003,24 @@ static int sd_probe(struct device *dev)
        sdkp->openers = 0;
        sdkp->previous_state = 1;
 
+       if (!sdp->request_queue->rq_timeout) {
+               if (sdp->type != TYPE_MOD)
+                       blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
+               else
+                       blk_queue_rq_timeout(sdp->request_queue,
+                                            SD_MOD_TIMEOUT);
+       }
+
+       device_initialize(&sdkp->dev);
+       sdkp->dev.parent = &sdp->sdev_gendev;
+       sdkp->dev.class = &sd_disk_class;
+       dev_set_name(&sdkp->dev, dev_name(&sdp->sdev_gendev));
+
+       if (device_add(&sdkp->dev))
+               goto out_free_index;
+
+       get_device(&sdp->sdev_gendev);
+
        async_schedule(sd_probe_async, sdkp);
 
        return 0;
@@ -2055,8 +2050,10 @@ static int sd_probe(struct device *dev)
  **/
 static int sd_remove(struct device *dev)
 {
-       struct scsi_disk *sdkp = dev_get_drvdata(dev);
+       struct scsi_disk *sdkp;
 
+       async_synchronize_full();
+       sdkp = dev_get_drvdata(dev);
        device_del(&sdkp->dev);
        del_gendisk(sdkp->disk);
        sd_shutdown(dev);