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Message-ID: <41b7b553-e7e7-58ae-532e-37234f21b80d@physik.fu-berlin.de>
Date:   Wed, 4 Jan 2023 23:42:22 +0100
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Subject: Re: [syzbot] [hfs?] WARNING in hfs_write_inode
To:     Arnd Bergmann <arnd@arndb.de>,
        Linus Torvalds <torvalds@linux-foundation.org>
Cc:     syzbot <syzbot+7bb7cd3595533513a9e7@syzkaller.appspotmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        christian.brauner@ubuntu.com,
        Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        jlayton@kernel.org, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
        Matthew Wilcox <willy@infradead.org>,
        ZhangPeng <zhangpeng362@huawei.com>,
        Viacheslav Dubeyko <slava@dubeyko.com>,
        linux-m68k@lists.linux-m68k.org
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From:   John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
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Hello Arnd!

On 1/4/23 23:33, Arnd Bergmann wrote:
> Adding Viacheslav Dubeyko to Cc, he's at least been reviewing
> patches for HFS and HFS+ somewhat recently. The linux-m68k
> list may have some users dual-booting old MacOS.

HFS/HFS+ is also used by PowerPC users on PowerMac hardware for both
exchanging data between MacOS and Linux as well as for booting Linux
using GRUB with a HFS/HFS+ /boot partition.

Debian's grub-installer creates an HFS partition from which GRUB loads
the kernel and the initrd [1]. In order to be able to update kernel and
initrd, the running Linux system needs to be able to read/write HFS/HFS+
partitions which is used for the /boot partition.

Adrian

> [1] https://salsa.debian.org/installer-team/grub-installer/-/blob/master/grub-installer#L918

-- 
  .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer
`. `'   Physicist
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