[U-Boot] [PATCH v2 04/23] fs: fat: make directory iterator global for write use

[AKASHI Takahiro]

On Wed, Sep 05, 2018 at 10:16:32AM +0200, Alexander Graf wrote:
> 
> 
> On 05.09.18 04:14, AKASHI Takahiro wrote:
> > On Tue, Sep 04, 2018 at 12:57:54PM +0200, Alexander Graf wrote:
> >>
> >>
> >>> Am 04.09.2018 um 12:50 schrieb Heinrich Schuchardt <xypron.glpk at gmx.de>:
> >>>
> >>>
> >>>
> >>>> On 09/04/2018 11:01 AM, Alexander Graf wrote:
> >>>>
> >>>>
> >>>>> On 04.09.18 09:49, AKASHI Takahiro wrote:
> >>>>> Directory iterator was introduced in major re-work of read operation by
> >>>>> Rob. We want to use it for write operation extensively as well.
> >>>>
> >>>> Please indicate in the commit message that write operations are
> >>>> implemented in a different .c file and so we have to export the
> >>>> respective functions.
> >>>
> >>> Why? Look at this ugly code:
> >>>
> >>> fs/fat/fat_write.c:17:#include "fat.c"
> >>
> >> In that case we don't need this patch at all, no?
> > 
> > Oops, I didn't notice this before.
> > If, however, "include fat.c" makes any sense, theoretically we don't need
> > "depends on FS_FAT" for FS_FAT_WRITE.
> > There seems to be a contradiction between the code and config.
> 
> I'm not sure it's contradictory. Someone just implemented a poor man's
> LTO by including the 2 files with each other.

Well, LTO has long existed since gcc4.8 ...
(and improvement would be quite small, I guess.)

> > I prefer just to remove the line, '#include "fat.c"' from fat_write.c
> > and add more "extern" definitions in fat.h if necessary.
> 
> We can worry about refactoring things later down the road. By making
> functions go external, we lose the compiler's ability to inline
> functions which may again bloat code which may trip random boards above
> size limits.
> 
> For now, I'd suggest you leave the ugly #include "fat.c" in and not move
> anything into fat.h. That way the file is self-contained and you don't
> have to worry about exporting just yet.

Although I won't tolerate such an ugly code, I will follow your suggestion
mainly because lots of existing defconfigs enable FAT_WRITE without
FS_FAT.

Thanks,
-Takahiro AKASHI

> 
> Alex