diff options
Diffstat (limited to 'drivers/md/raid5.c')
| -rw-r--r-- | drivers/md/raid5.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index e95219bf8859..19bbdbe1a52f 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -5388,11 +5388,16 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk safepos = conf->reshape_safe; sector_div(safepos, data_disks); if (mddev->reshape_backwards) { - writepos -= min_t(sector_t, reshape_sectors, writepos); + BUG_ON(writepos < reshape_sectors); + writepos -= reshape_sectors; readpos += reshape_sectors; safepos += reshape_sectors; } else { writepos += reshape_sectors; + /* readpos and safepos are worst-case calculations. + * A negative number is overly pessimistic, and causes + * obvious problems for unsigned storage. So clip to 0. + */ readpos -= min_t(sector_t, reshape_sectors, readpos); safepos -= min_t(sector_t, reshape_sectors, safepos); } |