Re: [Bug-tar] stat() on btrfs reports the st_blocks with delay (data loss in archivers)

[Paul Eggert]

On 07/06/2016 04:53 PM, Joerg Schilling wrote:
> Antonio Diaz Diaz<address@hidden>  wrote:
>
> > >Joerg Schilling wrote:
> > > > >POSIX requires st_blocks to be != 0 in case that the file contains data.
> > >
> > >Please, could you provide a reference? I can't find such requirement at
> > >http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_stat.h.html
>         blkcnt_t st_blocks      Number of blocks allocated for this object.

This doesn't require that st_blocks must be nonzero if the file contains 
nonzero data, any more that it requires that st_blocks must be nonzero 
if the file contains zero data. In either case, metadata outside the 
scope of st_blocks might contain enough information for the file system 
to represent all the file's data.