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Re: Overlapping #defines in isoinfra/current/include/sys/stat.h


Scott Wilkinson said:
> I was having a problem mounting JFFS2, which I tracked down to what I
> believe is a problem in /packages/isoinfra/current/include/sys/stat.h.
>
> The problem is that the (somewhat recent) addition of:
>
> #define __stat_mode_LNK    (1<<8)
> #define __stat_mode_SOCK   (1<<9)
> #define S_IFMT           (S_IFDIR|S_IFCHR|S_IFBLK|S_IFREG| \
>                           S_IFIFO|S_IFLNK|S_IFSOCK)
>
> conflicts with the long-standing definition of:
>
> #define S_IRUSR  (1<<8)
> #define S_IWUSR  (1<<9)
>
> This is a problem for JFFS which uses a single field to hold both
> mode and permission information.  This is manifested by problems when
> using S_IFMT to mask off the mode bits.  Problem is that it also catches
> the S_IRUSR|S_IWUSR permission bits, which confuses things.  (Check out
> os_to_jffs2_mode() in jffs2/current/src/os-ecos.h specifically.)
>
> I'm not sure what the correct answer is, but my solution was to change the
> definition of S_IFMT to remove the S_IFLNK|S_IFSOCK bits.  This may cause
> trouble with people who use links though?

I'd think it would be better to renumber the S_IRUSR... bits
to start with 16 which would give longer-term stability.

There shouldn't be any programs out there that use hard coded
bits, so this should be OK - or at least it should be possible
to make it work properly.

------------------------------------------------------------
Gary Thomas                 |
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email: <gary@mlbassoc.com>  |
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