Further avoid race conditions in the filesystem cache store.
Further avoid race conditions in the filesystem cache store.

PMArtz92/sass,hcatlin/sass,jaroot32/sass,Andrey-Pavlov/sass,srawlins/sass,schneems/sass,Anshdesire/sass,tangposmarvin/sass,xzyfer/sass,nicklima/sass,nickg33/sass,dylannnn/sass,amitsuroliya/sass,schneems/sass,jaroot32/sass,JuanitoFatas/sass,antonifs/sass,lmetla/sass,rammy7219/sass,DanteKaris/sass,PMArtz92/sass,srinivashappy/sass,antonifs/sass,dylannnn/sass,rammy7219/sass,stewx/sass,zaru/sass,zaru/sass,DanteKaris/sass,liquidmetal/sass,askl56/sass,Anshdesire/sass,Galactix/sass,StephanieMak/sass,Industrys/sass,HugoRLopes/sass,StephanieMak/sass,saper/sass,amitsuroliya/sass,modulexcite/sass,Iamronan/sass,nickg33/sass,Iamronan/sass,Ahnita/sass,liquidmetal/sass,Galactix/sass,Nzaga/sass,lmetla/sass,MetaAshley/sass,Industrys/sass,ridixcr/sass,Andrey-Pavlov/sass,srawlins/sass,ridixcr/sass,modulexcite/sass,cmpereirasi/sass,JuanitoFatas/sass,askl56/sass,danielfein/sass,OrenBochman/sass,HugoRLopes/sass,OrenBochman/sass,saper/sass,Nzaga/sass,tangposmarvin/sass,cmpereirasi/sass,xzyfer/sass,MetaAshley/sass,srinivashappy/sass,hcatlin/sass,nicklima/sass,Ahnita/sass,stewx/sass,danielfein/sass