Re: [f2fs-dev] [PATCH v5 2/2] f2fs: fix compat F2FS_IOC_{MOVE, GARBAGE_COLLECT}_RANGE

[Eric Biggers]

On Tue, Nov 10, 2020 at 09:24:37AM +0800, Chao Yu wrote:
> Eric reported a ioctl bug in below link:
> 
> https://lore.kernel.org/linux-f2fs-devel/20201103032234.GB2875@sol.localdomain/
> 
> That said, on some 32-bit architectures, u64 has only 32-bit alignment,
> notably i386 and x86_32, so that size of struct f2fs_gc_range compiled
> in x86_32 is 20 bytes, however the size in x86_64 is 24 bytes, binary
> compiled in x86_32 can not call F2FS_IOC_GARBAGE_COLLECT_RANGE successfully
> due to mismatched value of ioctl command in between binary and f2fs
> module, similarly, F2FS_IOC_MOVE_RANGE will fail too.
> 
> In this patch we introduce two ioctls for compatibility of above special
> 32-bit binary:
> - F2FS_IOC32_GARBAGE_COLLECT_RANGE
> - F2FS_IOC32_MOVE_RANGE
> 
> Reported-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>

Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>