Date: Wed, 31 Mar 2010 17:48:01 +0300 From: Andriy Gapon <avg@freebsd.org> To: Fabian Keil <freebsd-listen@fabiankeil.de> Cc: Kostik Belousov <kostikbel@gmail.com>, freebsd-current@freebsd.org, Bruce Evans <bde@zeta.org.au> Subject: Re: newfs_msdos and DVD-RAM Message-ID: <4BB360A1.7020309@freebsd.org> In-Reply-To: <4BB21BBA.7030407@freebsd.org> References: <3a142e751003190508x6a06868ene2e8fd9ddd977f66@mail.gmail.com> <3a142e751003191021p141af009m6acf7d160c890cbb@mail.gmail.com> <20100319191133.46fe271c@r500.local> <3a142e751003191126j331e525fwb9e5573bbf6f7d58@mail.gmail.com> <4BAA30CB.1070707@icyb.net.ua> <20100328172537.501ed3d1@r500.local> <4BB0A053.9060007@freebsd.org> <20100329222920.5eef6395@r500.local> <4BB111D4.8060809@freebsd.org> <20100330173637.202b4b1e@r500.local> <4BB21BBA.7030407@freebsd.org>
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on 30/03/2010 18:41 Andriy Gapon said the following:
> on 30/03/2010 18:36 Fabian Keil said the following:
>> Andriy Gapon <avg@freebsd.org> wrote:
>>
>>> on 29/03/2010 23:29 Fabian Keil said the following:
>>>> Andriy Gapon <avg@freebsd.org> wrote:
>>>>> Thus, clearly, it is a fault of a tool that formatted the media for FAT.
>>>>> It should have picked correct values, or rejected incorrect values if
>>>>> those were provided as overrides via command line options.
>>>> The kernel still shouldn't panic, though.
>>> A quick reply to this point only - yes, I completely agree.
>>> But remember that the panic happened only after the sources were modified :)
>> It wasn't clear from my message, but I was mainly referring to the
>> division-by-zero panic mentioned at the beginning of the thread,
>> for which I posted a work-around in <20100319191133.46fe271c@r500.local>.
>
> Oh, yes, right.
To clarify - I already forgot that the original problem was division by zero panic
and for some reason thought that it was EINVAL.
Anyways, here is a patch that I would use.
Unfortunately, ENOTIME to understand newfs_msdos code and fix it too,
--- a/sys/fs/msdosfs/msdosfs_vfsops.c
+++ b/sys/fs/msdosfs/msdosfs_vfsops.c
@@ -580,6 +580,7 @@ mountmsdosfs(struct vnode *devvp, struct mount *mp)
|| (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
|| (pmp->pm_HugeSectors == 0)
|| (pmp->pm_FATsecs == 0)
+ || (SecPerClust * pmp->pm_BlkPerSec > MAXBSIZE / DEV_BSIZE)
) {
error = EINVAL;
goto error_exit;
--
Andriy Gapon
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