From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 References: <20180627012421.80B8F24E094@nmr-admin> In-Reply-To: From: Geert Uytterhoeven Date: Sat, 30 Jun 2018 23:10:44 +0200 Message-ID: Subject: Re: Subject: [PATCH RFC] block: fix Amiga RDB partition support for disks >= 2 TB To: Michael Schmitz Cc: Jens Axboe , geert@linux-m68k.org-r, jdow , Martin Steigerwald , linux-m68k , linux-block@vger.kernel.org Content-Type: text/plain; charset="UTF-8" List-ID: Hi Michael, On Fri, Jun 29, 2018 at 11:12 AM Michael Schmitz wrote: > Am 28.06.18 um 01:30 schrieb Geert Uytterhoeven: > > On Wed, Jun 27, 2018 at 4:47 AM wrote: > >> From 5299e0e64dfb33ac3a1f3137b42178734ce20087 Mon Sep 17 00:00:00 2001 > > ?? > > > >> The Amiga RDB partition parser module uses int for partition sector > >> address and count, which will overflow for disks 2 TB and larger. > >> > >> Use sector_t as type for sector address and size (as expected by > >> put_partition) to allow using such disks without danger of data > >> corruption. > > Note that sector_t is not guaranteed to be 64-bit: > > > > #ifdef CONFIG_LBDAF > > typedef u64 sector_t; > > typedef u64 blkcnt_t; > > #else > > typedef unsigned long sector_t; > > typedef unsigned long blkcnt_t; > > #endif > > > > And it seems CONFIG_LBDAF can still be disabled on 32-bit... > > > > What are the ramifications of using a 2 TB disk on a kernel without > CONFIG_LBDAF? Are there any safeguards after the partition scan stage > that would prevent the kernel from using partitions on such a disk? > > Trying to decide whether we absolutely have to bail if sector_t is 32 > bit ... Sorry, I don't know. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds