On Mon, 12 Nov 2012 07:25:08 +0100, Jan Schmidt wrote: >>>> In kernel, qgroupid 0 is a special number when we run the quota group >>>> limit command. >>>> >>>> So, we should not be able to create a quota group whose id is 0, >>>> otherwise the kernel can't deal with it. Fix it. >>> >>> This is probably a stupid question - but if its not meant to be possible >>> to create such a thing shouldn't this be fixed in the kernel (as well as >>> here) to reject attempts from user space to create it? >>> >>> Otherwise it's possible for a non-aware program (or a user who is >>> playing) to still create it. >> >> Right. It also should be fixed in the kernel side, the patch is coming. >> >> But since we know which number is valid or not, it is better that we also check >> the arguments in the user tool before they are passed into the kernel. So, we >> can avoid trapping into the kernel, which will waste time, and output the error >> information as soon as possible. > > Have the kernel return with errno EINVAL is the way everyone else (I know about) > does this. > > I would avoid doing a check more than once where ever possible. Primarily, > because duplicating checks is error prone and in case of a kernel interface it > complicates future changes. You've got a point there. I'll send out the kernel patch. Thanks Miao -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
