From: Theodore Ts'o <tytso@mit.edu>
To: Rob Harris <rob.harris@gmail.com>
Cc: linux-ext4@vger.kernel.org
Subject: Re: Refreshing after OOB file update?
Date: Thu, 28 Aug 2014 19:32:37 -0400 [thread overview]
Message-ID: <20140828233237.GA31174@thunk.org> (raw)
In-Reply-To: <53FF3E90.1060200@gmail.com>
On Thu, Aug 28, 2014 at 10:37:04AM -0400, Rob Harris wrote:
>
> This tells me (probably naively) that the kernel is caching the old file
> contents.
Yes, that's what the page cache is all about.
> Is there a way for me to tell the file system that something out-of-band
> change a file contents and to force a re-read from the disk?
Have your userspace program do an O_DIRECT read. That will discard
the page cache and do a direct read from the disk.
Cheers,
- Ted
prev parent reply other threads:[~2014-08-28 23:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-28 14:37 Refreshing after OOB file update? Rob Harris
2014-08-28 23:32 ` Theodore Ts'o [this message]
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