Messages in this thread | | | Date | Wed, 4 Mar 2015 01:22:12 +0000 | From | Al Viro <> | Subject | Re: [RFC PATCH] vfs: Use 12:20 bit major:minor in stat everywhere |
| |
On Tue, Mar 03, 2015 at 05:10:22PM -0800, Daniel Ehrenberg wrote: > > What's to guarantee that your ABI change won't break any of those? > > I guess it's impossible to guarantee, but if there is an error, it'll > be that an -EOVERFLOW error is suppressed and the high bits of the > major:minor pair are shaved off by the userspace program. I would > suspect that this would just make debugging harder, rather than > actually break an automated program which counts on getting EOVERFLOW > from a huge block device, but no way to know. The block device has to > actually exist for this to happen, and all we're talking about is stat > failing. So it's replacing an an error code with erroneous way to get > data about a device node (erroneous just because userspace ignores > some of the bits with the answer).
All it takes is more than 16 SCSI disks, AFAICS, and use of open-coded MINOR() somewhere in old userland code...
| |