From: Linus Torvalds <torvalds@transmeta.com>
We should literally have the rule that any user-visible data structures
cannot use _any_ types other than u8/u16/u32/u64 (and _maybe_ the signed
ones, if there is any real reason to).
I agree very much with the statement that basic types
that occur in the kernel API should be explicitly given.
Not ino_t or __old_dev_t but int or long.
I agree less with the statement that they must be u32 instead of int.
My main reason is historical: the Unix interface is defined in terms
of char/int/long.
> +struct loop_info64 {
> + int lo_number; /* ioctl r/o */
> + unsigned long long lo_device; /* ioctl r/o */
> + unsigned long lo_inode; /* ioctl r/o */
> + unsigned long long lo_rdevice; /* ioctl r/o */
Make these be explicitly sized, and try to put the 64-bit members at the
beginning to avoid alignment and structure packing problems.
OK - will do.
(So far compatibility was so good that a private copy of the old
definition of struct loop_info could be used where the kernel
expects a struct loop_info64. Making more changes to struct loop_info64
diminishes compatibility, but
Any reason to keep an "offset" as "int"?
changing the type of offset destroys compatibility anyway.)
Andries
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This archive was generated by hypermail 2b29 : Wed Apr 23 2003 - 22:00:24 EST