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" <[email protected]> Signed-off-by: NeilBrown <[email protected]>
dokyukim · Oct 11, 2012 · b97390a · b97390a
1 parent 143c4d0
commit b97390a
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
@@ -2436,11 +2436,11 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
 		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,