Subject: Re: wd, disk write cache, sync cache, and softdep.
To: Steven M. Bellovin <firstname.lastname@example.org>
From: Jason Thorpe <email@example.com>
Date: 12/16/2004 13:57:21
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On Dec 16, 2004, at 10:35 AM, Steven M. Bellovin wrote:
> But under what conditions should higher layers set this flag?
Consider the case of a journaling file system.
Writes to the journal itself would be issued with FUA set.
As buffers described by the journal are flushed to disk, the journal
might decide it's time to advance the journal's "producer" pointer
(journal replay being the "consumer"). Before it does that, it would
issue a synchronize-cache command to the disk to ensure that all of
that data is, in fact, on disk. Then it would update the producer
Those are a couple of examples, anyway.
-- Jason R. Thorpe <firstname.lastname@example.org>
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