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Date: Mon, 18 Sep 2023 21:32:05 +0200 (CEST)
From: Jiri Kosina <jikos@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
cc: Jan Kara <jack@suse.cz>, Theodore Ts'o <tytso@mit.edu>, 
    NeilBrown <neilb@suse.de>, 
    James Bottomley <James.Bottomley@hansenpartnership.com>, 
    Dave Chinner <david@fromorbit.com>, Eric Sandeen <sandeen@sandeen.net>, 
    Steven Rostedt <rostedt@goodmis.org>, Guenter Roeck <linux@roeck-us.net>, 
    Christoph Hellwig <hch@infradead.org>, ksummit@lists.linux.dev, 
    linux-fsdevel@vger.kernel.org
Subject: Re: [MAINTAINERS/KERNEL SUMMIT] Trust and maintenance of file
 systems
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On Mon, 18 Sep 2023, Linus Torvalds wrote:

> But mmap() is *not* important for a filesystem that is used just for 
> data transport. I bet that FAT is still widely used, for example, and 
> while exFAT is probably making inroads, I suspect most of us have used a 
> USB stick with a FAT filesystem on it in the not too distant past. Yet I 
> doubt we'd have ever even noticed if 'mmap' didn't work on FAT. Because 
> all you really want for data transport is basic read/write support.

I am afraid this is not reflecting reality.

I am pretty sure that "give me that document on a USB stick, and I'll take 
a look" leads to using things like libreoffice (or any other editor liked 
by general public) to open the file directly on the FAT USB stick. And 
that's pretty much guaranteed to use mmap().

-- 
Jiri Kosina
SUSE Labs