From: NeilBrown Date: Tue, 26 May 2009 02:41:08 +0000 (+1000) Subject: md: raid5: avoid sector values going negative when testing reshape progress. X-Git-Tag: v3.12-rc1~14494^2~3 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=848b3182365fdf5a05bcd5ed949071cac2c894b3;p=kernel%2Fkernel-generic.git md: raid5: avoid sector values going negative when testing reshape progress. As sector_t in unsigned, we cannot afford to let 'safepos' etc go negative. So replace a -= b; by a -= min(b,a); Signed-off-by: NeilBrown --- diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 4616bc3..3c3626d 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -3811,13 +3811,13 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped safepos = conf->reshape_safe; sector_div(safepos, data_disks); if (mddev->delta_disks < 0) { - writepos -= reshape_sectors; + writepos -= min(reshape_sectors, writepos); readpos += reshape_sectors; safepos += reshape_sectors; } else { writepos += reshape_sectors; - readpos -= reshape_sectors; - safepos -= reshape_sectors; + readpos -= min(reshape_sectors, readpos); + safepos -= min(reshape_sectors, safepos); } /* 'writepos' is the most advanced device address we might write.