From: Matthew Wilcox <willy@infradead.org>
To: Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc: Linux FS Devel <linux-fsdevel@vger.kernel.org>,
"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: page->index limitation on 32bit system?
Date: Thu, 18 Feb 2021 12:15:03 +0000 [thread overview]
Message-ID: <20210218121503.GQ2858050@casper.infradead.org> (raw)
In-Reply-To: <1783f16d-7a28-80e6-4c32-fdf19b705ed0@gmx.com>
On Thu, Feb 18, 2021 at 04:54:46PM +0800, Qu Wenruo wrote:
> Recently we got a strange bug report that, one 32bit systems like armv6
> or non-64bit x86, certain large btrfs can't be mounted.
>
> It turns out that, since page->index is just unsigned long, and on 32bit
> systemts, that can just be 32bit.
>
> And when filesystems is utilizing any page offset over 4T, page->index
> get truncated, causing various problems.
4TB? I think you mean 16TB (4kB * 4GB)
Yes, this is a known limitation. Some vendors have gone to the trouble
of introducing a new page_index_t. I'm not convinced this is a problem
worth solving. There are very few 32-bit systems with this much storage
on a single partition (everything should work fine if you take a 20TB
drive and partition it into two 10TB partitions).
As usual, the best solution is for people to stop buying 32-bit systems.
next prev parent reply other threads:[~2021-02-18 15:24 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-18 8:54 page->index limitation on 32bit system? Qu Wenruo
2021-02-18 12:15 ` Matthew Wilcox [this message]
2021-02-18 12:42 ` Qu Wenruo
2021-02-18 13:39 ` Matthew Wilcox
2021-02-19 0:37 ` Qu Wenruo
2021-02-19 16:12 ` Theodore Ts'o
2021-02-19 23:10 ` Qu Wenruo
2021-02-20 0:23 ` Matthew Wilcox
2021-02-22 0:19 ` Dave Chinner
2021-02-20 2:20 ` Erik Jensen
2021-02-20 3:40 ` Matthew Wilcox
2021-02-20 23:02 ` Erik Jensen
2021-02-20 23:22 ` Matthew Wilcox
2021-02-21 0:01 ` Erik Jensen
2021-02-21 17:15 ` Matthew Wilcox
2021-02-18 21:27 ` Erik Jensen
2021-02-19 14:22 ` Matthew Wilcox
2021-02-19 17:51 ` Matthew Wilcox
2021-02-19 23:13 ` Qu Wenruo
2021-02-22 1:48 ` Dave Chinner
2021-03-01 1:49 ` GWB
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