fsync() and error checking in EFSSubmissionEnd().
fsync() and error checking in EFSSubmissionEnd().

Performance takes another dive.

guiquanz/stronglink,btrask/stronglink,iOSCowboy/stronglink,btrask/stronglink,feld/stronglink,btrask/stronglink,rmoorman/stronglink,Lacra17/stronglink,Lacra17/stronglink,Ryezhang/stronglink,nkatsaros/stronglink,rmoorman/stronglink,nkatsaros/stronglink,nkatsaros/stronglink,Ryezhang/stronglink,shaunstanislaus/stronglink,feld/stronglink,guiquanz/stronglink,yamingd/stronglink,yamingd/stronglink,shaunstanislaus/stronglink,iOSCowboy/stronglink,yamingd/stronglink,shaunstanislaus/stronglink,rmoorman/stronglink,Lacra17/stronglink,feld/stronglink,Ryezhang/stronglink,iOSCowboy/stronglink,btrask/stronglink,guiquanz/stronglink