Checking/Fixing Badblocks on LVM/Ext3

I have this LVM setup:

/dev/mapper/vgshare-lvshare 3845719048 794973932 2855393772 22% /storage

These are physical disks /sdd & /sde. Which I’d like to fsck(?) on because the system locked when I was trying to copy stuff from another disk and then locked again when I tried to delete the directory through the (gnome) GUI. From what I understand I need to umount and then check. But with LVM mixed in there I’m at a loss of the exact way of doing it and don’t want to completely mess the LVM data up.

Continuing on a tangent, I went into the command line to the offending directory as su and successfully deleted it that way. I did this once accidentally (I forgot), but have noticed a trend of being able to delete stuff that would otherwise lock the GUI. I can’t remember if I was su each time but I’m just wondering what the reasons are. (Even if it is su each time - Is it simply the fact permissions are messed up along the way and su can force the issue?)