Andrew Morton writes: > On Mon, 18 Jun 2007 12:21:47 +0400 > Vasily Tarasov <[EMAIL PROTECTED]> wrote: > > > From: Vasily Tarasov <[EMAIL PROTECTED]> > > > > This patch should be applied after Arnd Bergmann's patch, > > that intoduces new compat types: > > http://lkml.org/lkml/2007/6/15/98 > > > > OpenVZ Linux kernel team has discovered the problem > > with 32bit quota tools working on 64bit architectures. > > In 2.6.10 kernel sys32_quotactl() function was replaced by sys_quotactl() > > with > > the comment "sys_quotactl seems to be 32/64bit clean, enable it for 32bit" > > However this isn't right. Look at if_dqblk structure: > > > > struct if_dqblk { > > __u64 dqb_bhardlimit; > > __u64 dqb_bsoftlimit; > > __u64 dqb_curspace; > > __u64 dqb_ihardlimit; > > __u64 dqb_isoftlimit; > > __u64 dqb_curinodes; > > __u64 dqb_btime; > > __u64 dqb_itime; > > __u32 dqb_valid; > > }; > > > > For 32 bit quota tools sizeof(if_dqblk) == 0x44. > > But for 64 bit kernel its size is 0x48, 'cause of alignment! > > Thus we got a problem. Attached patch reintroduce sys32_quotactl() > > function, > > that handles this and related situations. > > > > Signed-off-by: Vasily Tarasov <[EMAIL PROTECTED]> > > > > --- > > > > In OpenVZ technology 32 bit Virtual Environments over > > 64 bit OS are common, hence we have customers, that complains on this bad > > quota > > behaviour: > > > > # /usr/bin/quota > > quota: error while getting quota from /dev/sda1 for 0: Success > > > > The reason is caused above. > > Only x86_64 and ia64 are fixed. Would it be correct to assume that the > other CONFIG_COMPAT architectures also need to be fixed?
I complained about this very issue when a previous version of this patch was submitted last week, and Arnd explained that non-x86 doesn't have a problem here because alignof(u64) is the same in 32- and 64-bit modes. However, the fact that the patch description talks about 32- and 64-bit machines _in_general_, while the patch clearly only handles x86-32 on x86-64 and ia64, is itself a bug. A more precise patch description and a better comment in the code is in order, I think. /Mikael _______________________________________________ Devel mailing list Devel@openvz.org https://openvz.org/mailman/listinfo/devel