On Fri, Mar 06, 2009 at 03:02:21PM -0800, bugme-daemon@xxxxxxxxxxxxxxxxxxx wrote: > > > ------- Comment #1 from tytso@xxxxxxx 2009-03-06 15:02 ------- > What are the precise reproduction details? We're supposed to keep track of > how many delayed allocation blocks are outstanding, so that we return ENOSPC > *before* we get to this stage. Yes. We should not get the ENOSPC during writeback. That would imply the block reservation is going wrong. > > I'm not sure we do the right thing if we mmap into an unallocated region of > file; when do we actually track delayed allocation blocks? The right answer > would be at mmap() time, but OTOH that means if we mmap a 2GB region, do we > immediately take a 2GB charge because the process might write into this region? > And does free space returned by 'df' immediately drop by 2GB? For mmap block reservation is doing during page_mkwrite. > > Do you know if there was any allocation by mmap going on in your reproduction > case? That seems the most likely cause to me, if I had to guess.... > -aneesh -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html