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From: Miklos Szeredi <>
To: Dan Schatzberg <>
Cc: Tejun Heo <>, Kernel Team <>,
	"" <>,
	"" <>
Subject: Re: [PATCH] fuse: enable caching of symlinks
Date: Wed, 10 Oct 2018 10:29:39 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On Tue, Oct 2, 2018 at 11:33 PM, Dan Schatzberg <> wrote:
> On 9/27/18, 9:59 AM, "Miklos Szeredi" <> wrote:
>>  On Thu, Sep 27, 2018 at 3:52 PM, Dan Schatzberg <> wrote:
>>> FUSE file reads are cached in the page cache, but symlink reads are
>>> not. This patch enables FUSE READLINK operations to be cached which
>>> can improve performance of some FUSE workloads.
>>> In particular, I'm working on a FUSE filesystem for access to source
>>> code and discovered that about a 10% improvement to build times is
>>> achieved with this patch (there are a lot of symlinks in the source
>>> tree).
>>> Please provide feedback, I'm looking to flesh this out more.
>> Need to think about how/when to invalidate the cached symlink
>> contents.  I think treating it like metadata (i.e. look at
>> attr_timeout for validity) would be the simplest.
>> Thanks,
>> Miklos
> Any further thoughts on this? Just so I can confirm my understanding,
> the attached patch will unconditionally cache READLINK responses
> However, based on the entry timeout provided by the LOOKUP response,
> Userspace can decide to invalidate this by providing a different inode on
> a subsequent LOOKUP (e.g. during fuse_dentry_revalidate())


> Would you like there to be a way to invalidate the cached symlink without
>  changing the inode via LOOKUP?

No, that would make no sense, since symlink contents are not mutable.
This was just a braino on my part.

I still worry about backward compatibility, though.  So we should add
a flag to negotiate symlink caching in with the INIT request.


  reply	other threads:[~2018-10-10 15:50 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-27 13:52 [PATCH] fuse: enable caching of symlinks Dan Schatzberg
2018-09-27 13:58 ` Miklos Szeredi
2018-10-02 21:33   ` Dan Schatzberg
2018-10-10  8:29     ` Miklos Szeredi [this message]
2018-10-09 14:29   ` Dan Schatzberg

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