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To: sbruno@freebsd.org, Sean Bruno <sean_bruno@yahoo.com>
Subject: Re: kern/vfs_mount.c vfs_donmount() checks of MFSNAMELEN 
In-reply-to: <1379951941.1612.3.camel@localhost> 
Date: Mon, 23 Sep 2013 11:02:20 -0700
From: Kirk McKusick <mckusick@mckusick.com>
Cc: freebsd-fs <freebsd-fs@freebsd.org>
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> From: Sean Bruno <sean_bruno@yahoo.com>
> Subject: kern/vfs_mount.c vfs_donmount() checks of MFSNAMELEN
> To: freebsd-fs <freebsd-fs@freebsd.org>
> Date: Mon, 23 Sep 2013 08:59:01 -0700
> 
> So, I'm confused by this check:
> 
>         if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) {
>                 error = ENAMETOOLONG;
>                 goto bail;
>         }
> 
> MFSNAMELEN is 16, why do we check against >= MFSNAMELEN - 1?  Why dont
> we check against (> MFSNAMELEN - 1) or (>= MFSNAMELEN)?  Is a 14
> character fstypelen with a "\0" at the end considered too long?
> 
> Sean
> 
> p.s. e.g. mount -t fuse.glusterfs ...

I agree with you. It should either be (> MFSNAMELEN - 1) or (>= MFSNAMELEN).

	Kirk McKusick