Re: [PATCH] e4defrag: fix build when posix_fadvise is missing

[Theodore Ts'o <tytso@mit.edu>]

On Wed, Jan 01, 2014 at 09:08:00PM +0200, Baruch Siach wrote:
> 
> Yes. uClibc does provide posix_fadvise64() when __NR_fadvise64_64 is 
> available.
> 
> > Maybe the better fix would be to try to use posix_fadvise64 if it is exists, 
> > with posix_fadvise() and the locally defined posix_fadvise() as fallbacks.
> 
> OK. So you suggest to add another autoconf test for posix_fadvise64 and use 
> that as a fall back before trying direct syscall()?

Yes, I think that's the more general and hence the more correct
answer.  In fact what we have right now is arguably wrong, since on a
32-bit platform where off_t is 32-bits, and which defines
posix_fadvise, we wouldn't correctly handle files that are larger than
2GB.  So if posix_fadvise64 exists, we should be using in preference
to posix_fadvise(), even if both are provided by the C library.

Would you mind sending such a revised patch?

Many thanks!!

						- Ted