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From: Andrei Borzenkov <arvidjaar@gmail.com>
To: Chris Mason <clm@fb.com>,
	kreijack@inwind.it, linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: [BUG] Btrfs scrub sometime recalculate wrong parity in raid5: take two
Date: Fri, 15 Jul 2016 19:34:38 +0300	[thread overview]
Message-ID: <5789109E.7090301@gmail.com> (raw)
In-Reply-To: <4bdb4c42-ed13-3add-1da7-46a1acd8390e@fb.com>

15.07.2016 19:29, Chris Mason пишет:
>
>> However I have to point out that this kind of test is very
>> difficult to do: the file-cache could lead to read an old data, so please
>> suggestion about how flush the cache are good (I do some sync,
>> unmount the filesystem and perform "echo 3 >/proc/sys/vm/drop_caches",
>> but sometime it seems not enough).
> 
> O_DIRECT should handle the cache flushing for you.
> 

There is also BLKFLSBUF ioctl (blockdev --flushbufs on shell level).

  reply	other threads:[~2016-07-15 16:34 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-12 21:50 [BUG] Btrfs scrub sometime recalculate wrong parity in raid5: take two Goffredo Baroncelli
2016-07-14 21:20 ` Chris Mason
2016-07-15  4:39   ` Andrei Borzenkov
2016-07-15 13:20     ` Chris Mason
2016-07-15 15:10       ` Andrei Borzenkov
2016-07-15 15:21         ` Chris Mason
2016-07-15 16:30     ` Goffredo Baroncelli
2016-07-15 16:28   ` Goffredo Baroncelli
2016-07-15 16:29     ` Chris Mason
2016-07-15 16:34       ` Andrei Borzenkov [this message]
2016-07-16 15:51 ` [BUG] Btrfs scrub sometime recalculate wrong parity in raid5 Jarkko Lavinen
2016-07-17 19:46   ` Jarkko Lavinen
2016-07-18 18:56   ` Goffredo Baroncelli

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