Comment more on the entire series than on this patch: scenario that causes trouble * foo is a sparse file on ufs with 8Kb block/1Kb fragment * process opens it writable and mmaps it shared * it proceeds to dirty the pages * fork * parent and child do msync() on pages next to each other I.e. we try to write adjacent pages that sit in the same block. At the same time. Each will trigger an allocation and we'd better be very careful, or we'll end up allocating the same block twice. - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html