md/raid5: use conf->raid_disks in preference to mddev->raid_disk

mddev->raid_disks can be changed and any time by a request from
user-space.  It is a suggestion as to what number of raid_disks is
desired.

conf->raid_disks can only be changed by the raid5 module with suitable
locks in place.  It is a statement as to the current number of
raid_disks.

There are two places where the latter should be used, but the former
is used.  This can lead to a crash when reshaping an array.

This patch changes to mddev-> to conf->

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 5d400ae..75469e6 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3288,7 +3288,7 @@ static void unplug_slaves(mddev_t *mddev)
        int i;
 
        rcu_read_lock();
-       for (i=0; i<mddev->raid_disks; i++) {
+       for (i = 0; i < conf->raid_disks; i++) {
                mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
                if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
                        struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
@@ -4034,7 +4034,7 @@ static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *ski
         * We don't need to check the 'failed' flag as when that gets set,
         * recovery aborts.
         */
-       for (i=0; i<mddev->raid_disks; i++)
+       for (i = 0; i < conf->raid_disks; i++)
                if (conf->disks[i].rdev == NULL)
                        still_degraded = 1;