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From: Christoph Hellwig <hch@infradead.org>
To: Josef Bacik <josef@toxicpanda.com>
Cc: linux-fsdevel@vger.kernel.org
Subject: Re: [LSF/MM/BPF TOPIC] Changing reference counting rules for inodes
Date: Tue, 4 Mar 2025 15:34:00 -0800	[thread overview]
Message-ID: <Z8eN6Nd1iuQC2noS@infradead.org> (raw)
In-Reply-To: <20250303170029.GA3964340@perftesting>

On Mon, Mar 03, 2025 at 12:00:29PM -0500, Josef Bacik wrote:
> Hello,
> 
> I've recently gotten annoyed with the current reference counting rules that
> exist in the file system arena, specifically this pattern of having 0
> referenced objects that indicate that they're ready to be reclaimed.

The other way around is worse.  E.g. the xfs_buf currently holds a
reference of 1 for buffers on the LRU, which makes a complete mess of
the buf rele and related code.  And it prevents us from using the
lockref primitive.  Switching it to have a refcount of zero greatly
cleans this up:

http://git.infradead.org/?p=users/hch/xfs.git;a=commitdiff;h=8b46634dd6199f332f09e6f730a7a8801547c8b5

I suspect the inode just needs more clear rules about what state an
inode can be in.


      parent reply	other threads:[~2025-03-04 23:34 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-03 17:00 [LSF/MM/BPF TOPIC] Changing reference counting rules for inodes Josef Bacik
2025-03-04  8:04 ` Dave Chinner
2025-03-04 15:02   ` Josef Bacik
2025-03-04 22:23     ` Dave Chinner
2025-03-04 10:19 ` Christian Brauner
2025-03-04 14:56   ` Josef Bacik
2025-03-04 22:44 ` Matthew Wilcox
2025-03-04 23:34 ` Christoph Hellwig [this message]

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