From: Andre Noll <maan@tuebingen.mpg.de>
To: Dave Chinner <david@fromorbit.com>
Cc: Nix <nix@esperi.org.uk>,
linux-bcache@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-kernel@vger.kernel.org, Coly Li <colyli@suse.de>
Subject: Re: bcache on XFS: metadata I/O (dirent I/O?) not getting cached at all?
Date: Thu, 7 Feb 2019 01:24:25 +0100 [thread overview]
Message-ID: <20190207002425.GX24140@tuebingen.mpg.de> (raw)
In-Reply-To: <20190206234328.GH14116@dastard>
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On Thu, Feb 07, 10:43, Dave Chinner wrote
> File data readahead: REQ_RAHEAD
> Metadata readahead: REQ_META | REQ_RAHEAD
>
> drivers/md/bcache/request.c::check_should_bypass():
>
> /*
> * Flag for bypass if the IO is for read-ahead or background,
> * unless the read-ahead request is for metadata (eg, for gfs2).
> */
> if (bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND) &&
> !(bio->bi_opf & REQ_PRIO))
> goto skip;
>
> bcache needs fixing - it thinks REQ_PRIO means metadata IO. That's
> wrong - REQ_META means it's metadata IO, and so this is a bcache
> bug.
Do you think 752f66a75abad is bad (ha!) and should be reverted?
Thanks
Andre
--
Max Planck Institute for Developmental Biology
Max-Planck-Ring 5, 72076 Tübingen, Germany. Phone: (+49) 7071 601 829
http://people.tuebingen.mpg.de/maan/
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next prev parent reply other threads:[~2019-02-07 0:53 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-06 22:11 Nix
2019-02-06 23:43 ` Dave Chinner
2019-02-07 0:24 ` Andre Noll [this message]
2019-02-07 2:26 ` Dave Chinner
2019-02-07 2:38 ` Coly Li
2019-02-07 3:10 ` Dave Chinner
2019-02-07 8:18 ` Coly Li
2019-02-07 13:10 ` Nix
2019-02-07 2:27 ` Coly Li
2019-02-07 9:28 ` Andre Noll
2019-02-07 8:16 ` Coly Li
2019-02-07 9:41 ` Andre Noll
2019-02-07 10:23 ` Coly Li
2019-02-07 20:51 ` Nix
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