Try chkdsk or fsck depending upon the host-side filesystem - if this doesn't work, offline & un-map the lun and perform a 'snap restore' of particular LUNs or entire volume from a previous known working date snap (depending upon whether it is one-2-one or one-2-many setup). After LUN restore from 'snapshot', re-map the LUN to igroup-of-the-host and try assessing things. If you have flex-clone licensed, you can choose a previous good snap and make a clone and then present those luns to the same host and if that works, split it which runs in the background. Number of options to try. (may not be that straightforward in all scenarios but do start trying).