md/raid5: protect debug message against NULL derefernce.
The pr_debug in add_stripe_bio could race with something
changing *bip, so it is best to hold the lock until
after the pr_debug.
Reported-by: "Jianpeng Ma" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 36c0a15..d110126 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2436,11 +2436,11 @@
if (sector >= sh->dev[dd_idx].sector + STRIPE_SECTORS)
set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags);
}
- spin_unlock_irq(&sh->stripe_lock);
pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
(unsigned long long)(*bip)->bi_sector,
(unsigned long long)sh->sector, dd_idx);
+ spin_unlock_irq(&sh->stripe_lock);
if (conf->mddev->bitmap && firstwrite) {
bitmap_startwrite(conf->mddev->bitmap, sh->sector,