md: never advance 'events' counter by more than 1.

[safe/jmp/linux-2.6] / drivers / md / md.c

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5b98bea..d18805f 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -359,6 +359,7 @@ static mddev_t * mddev_find(dev_t unit)
        else
                new->md_minor = MINOR(unit) >> MdpMinorShift;
 
+       mutex_init(&new->open_mutex);
        mutex_init(&new->reconfig_mutex);
        INIT_LIST_HEAD(&new->disks);
        INIT_LIST_HEAD(&new->all_mddevs);
@@ -1974,17 +1975,14 @@ repeat:
                /* otherwise we have to go forward and ... */
                mddev->events ++;
                if (!mddev->in_sync || mddev->recovery_cp != MaxSector) { /* not clean */
-                       /* .. if the array isn't clean, insist on an odd 'events' */
-                       if ((mddev->events&1)==0) {
-                               mddev->events++;
+                       /* .. if the array isn't clean, an 'even' event must also go
+                        * to spares. */
+                       if ((mddev->events&1)==0)
                                nospares = 0;
-                       }
                } else {
-                       /* otherwise insist on an even 'events' (for clean states) */
-                       if ((mddev->events&1)) {
-                               mddev->events++;
+                       /* otherwise an 'odd' event must go to spares */
+                       if ((mddev->events&1))
                                nospares = 0;
-                       }
                }
        }
 
@@ -4304,12 +4302,11 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
        struct gendisk *disk = mddev->gendisk;
        mdk_rdev_t *rdev;
 
+       mutex_lock(&mddev->open_mutex);
        if (atomic_read(&mddev->openers) > is_open) {
                printk("md: %s still in use.\n",mdname(mddev));
-               return -EBUSY;
-       }
-
-       if (mddev->pers) {
+               err = -EBUSY;
+       } else if (mddev->pers) {
 
                if (mddev->sync_thread) {
                        set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
@@ -4367,7 +4364,10 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                        set_disk_ro(disk, 1);
                clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
        }
-
+out:
+       mutex_unlock(&mddev->open_mutex);
+       if (err)
+               return err;
        /*
         * Free resources if final stop
         */
@@ -4433,7 +4433,6 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
        blk_integrity_unregister(disk);
        md_new_event(mddev);
        sysfs_notify_dirent(mddev->sysfs_state);
-out:
        return err;
 }
 
@@ -5518,12 +5517,12 @@ static int md_open(struct block_device *bdev, fmode_t mode)
        }
        BUG_ON(mddev != bdev->bd_disk->private_data);
 
-       if ((err = mutex_lock_interruptible_nested(&mddev->reconfig_mutex, 1)))
+       if ((err = mutex_lock_interruptible(&mddev->open_mutex)))
                goto out;
 
        err = 0;
        atomic_inc(&mddev->openers);
-       mddev_unlock(mddev);
+       mutex_unlock(&mddev->open_mutex);
 
        check_disk_change(bdev);
  out: