On Wed, Feb 26, 2020 at 03:27:08PM +0530, Ritesh Harjani wrote: > Currently FIEMAP_EXTENT_LAST is not working consistently across > different filesystem's fiemap implementations and thus this feature > may be broken. So fix the documentation about this flag to meet the > right expectations. Are you saying filesystems have both false positives and false negatives? I can understand how a filesystem might fail to set FIEMAP_EXTENT_LAST, but not how a filesystem might set it when there's actually another extent beyond this one. > * FIEMAP_EXTENT_LAST > -This is the last extent in the file. A mapping attempt past this > -extent will return nothing. > +This is generally the last extent in the file. A mapping attempt past this > +extent may return nothing. But the user must still confirm by trying to map > +past this extent, since different filesystems implement this differently.