Re: [RFC] Copy as much as you can during a 32-bit stat before returning EOVERFLOW?

[Paul Eggert <eggert@cs.ucla.edu>]

On 02/26/13 11:55, Carlos O'Donell wrote:> Community,

> The correct solution is going to take time to implement

Don't the proposed patches to xstatconv.c etc. slow down glibc
slightly for the normal (successful) case?  That's a minus.

Here's a different idea: enable wide ino_t, time_t, etc. if
_FILE_OFFSET_BITS is 64.  This would require zero changes to
applications that are portable and largefile aware, as they
already define _FILE_OFFSET_BITS.  And even for nonportable
applications, compiling with -D_FILE_OFFSET_BITS=64 (and fixing any
resulting porting glitches) should take less time and should be safer
than modifying the applications to make the unportable assumption that a
struct stat is filled in if errno == EOVERFLOW.

A more-conservative variant of this idea would establish a new symbol
that means "use wide-enough values for all file-related types".
-D_WIDE_FILE_TYPES, say, would use wide types for off_t, time_t,
ino_t, etc.  Portable application developers could modify their code
to set this symbol as well as setting _FILE_OFFSET_BITS, which is a
bit of a hassle, but I've seen worse (e.g., Mac OS X uses
_DARWIN_USE_64_BIT_INODE to select 64-bit inodes, but that's all it
does -- yuck).