1 files changed, 47 insertions, 11 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 6c06e825cff5..509171ca7fa8 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1318,6 +1318,7 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
         char b[BDEVNAME_SIZE];
         struct kobject *ko;
         char *s;
+        int err;
 
         if (rdev->mddev) {
                 MD_BUG();
@@ -1352,20 +1353,35 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
         while ( (s=strchr(rdev->kobj.k_name, '/')) != NULL)
                 *s = '!';
                         
-        list_add(&rdev->same_set, &mddev->disks);
         rdev->mddev = mddev;
         printk(KERN_INFO "md: bind<%s>\n", b);
 
         rdev->kobj.parent = &mddev->kobj;
-        kobject_add(&rdev->kobj);
+        if ((err = kobject_add(&rdev->kobj)))
+                goto fail;
 
         if (rdev->bdev->bd_part)
                 ko = &rdev->bdev->bd_part->kobj;
         else
                 ko = &rdev->bdev->bd_disk->kobj;
-        sysfs_create_link(&rdev->kobj, ko, "block");
+        if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
+                kobject_del(&rdev->kobj);
+                goto fail;
+        }
+        list_add(&rdev->same_set, &mddev->disks);
         bd_claim_by_disk(rdev->bdev, rdev, mddev->gendisk);
         return 0;
+
+ fail:
+        printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
+               b, mdname(mddev));
+        return err;
+}
+
+static void delayed_delete(struct work_struct *ws)
+{
+        mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
+        kobject_del(&rdev->kobj);
 }
 
 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
@@ -1380,7 +1396,12 @@ static void unbind_rdev_from_array(mdk_rdev_t * rdev)
         printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
         rdev->mddev = NULL;
         sysfs_remove_link(&rdev->kobj, "block");
-        kobject_del(&rdev->kobj);
+
+        /* We need to delay this, otherwise we can deadlock when
+         * writing to 'remove' to "dev/state"
+         */
+        INIT_WORK(&rdev->del_work, delayed_delete);
+        schedule_work(&rdev->del_work);
 }
 
 /*
@@ -2966,7 +2987,9 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
         mddev->kobj.k_name = NULL;
         snprintf(mddev->kobj.name, KOBJ_NAME_LEN, "%s", "md");
         mddev->kobj.ktype = &md_ktype;
-        kobject_register(&mddev->kobj);
+        if (kobject_register(&mddev->kobj))
+                printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
+                       disk->disk_name);
         return NULL;
 }
 
@@ -3144,9 +3167,12 @@ static int do_md_run(mddev_t * mddev)
                 bitmap_destroy(mddev);
                 return err;
         }
-        if (mddev->pers->sync_request)
-                sysfs_create_group(&mddev->kobj, &md_redundancy_group);
-        else if (mddev->ro == 2) /* auto-readonly not meaningful */
+        if (mddev->pers->sync_request) {
+                if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
+                        printk(KERN_WARNING
+                               "md: cannot register extra attributes for %s\n",
+                               mdname(mddev));
+        } else if (mddev->ro == 2) /* auto-readonly not meaningful */
                 mddev->ro = 0;
 
         atomic_set(&mddev->writes_pending,0);
@@ -3160,7 +3186,9 @@ static int do_md_run(mddev_t * mddev)
                 if (rdev->raid_disk >= 0) {
                         char nm[20];
                         sprintf(nm, "rd%d", rdev->raid_disk);
-                        sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
+                        if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
+                                printk("md: cannot register %s for %s\n",
+                                       nm, mdname(mddev));
                 }
         
         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
@@ -3325,6 +3353,7 @@ static int do_md_stop(mddev_t * mddev, int mode)
                         mddev->queue->merge_bvec_fn = NULL;
                         mddev->queue->unplug_fn = NULL;
                         mddev->queue->issue_flush_fn = NULL;
+                        mddev->queue->backing_dev_info.congested_fn = NULL;
                         if (mddev->pers->sync_request)
                                 sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
 
@@ -3371,6 +3400,9 @@ static int do_md_stop(mddev_t * mddev, int mode)
                                 sysfs_remove_link(&mddev->kobj, nm);
                         }
 
+                /* make sure all delayed_delete calls have finished */
+                flush_scheduled_work();
+
                 export_array(mddev);
 
                 mddev->array_size = 0;
@@ -5385,8 +5417,12 @@ static int remove_and_add_spares(mddev_t *mddev)
                                 if (mddev->pers->hot_add_disk(mddev,rdev)) {
                                         char nm[20];
                                         sprintf(nm, "rd%d", rdev->raid_disk);
-                                        sysfs_create_link(&mddev->kobj,
-                                                          &rdev->kobj, nm);
+                                        if (sysfs_create_link(&mddev->kobj,
+                                                              &rdev->kobj, nm))
+                                                printk(KERN_WARNING
+                                                       "md: cannot register "
+                                                       "%s for %s\n",
+                                                       nm, mdname(mddev));
                                         spares++;
                                         md_new_event(mddev);
                                 } else