Re: [PATCH] ext4: Ensure Inode flags consistency are checked in build time [V2]

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

On Mon, Dec 03, 2012 at 03:32:56PM -0200, Carlos Maiolino wrote:
> Flags being used by atomic operations in inode flags (e.g.
> ext4_test_inode_flag(), should be consistent with that actually stored in
> inodes, i.e.: EXT4_XXX_FL.
> 
> It ensures that this consistency is checked at build-time, not at run-time.
> 
> Currently, the flags consistency are being checked at run-time, but, there is no
> real reason to not do a build-time check instead of a run-time check. The code
> is comparing macro defined values with enum type variables, where both are
> constants, so, there is no problem in comparing constants at build-time.
> 
> enum variables are treated as constants by the C compiler, according to the C99
> specs (see www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf sec. 6.2.5, item
> 16), so, there is no real problem in comparing an enumeration type at build time
> 
> CC'ing Sergio who helped me to achieve this conclusion, in case there is
> something else we need to discuss.
> 
> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>

Thanks, applied.

						- Ted