Re: [BUG] dmesg: "invalidate: busy buffer"

[Andrew Morton]

Ryan Mack wrote:
> 
> The last two days my dmesg buffer has be filled with "invalidate: busy
> buffer" messages.  I tried rebooting (and forcing a fsck), but after about
> 12 hours they came back.
> 
> I'm running 2.4.17 on a dual P3, Intel 440BX chipset.  Both filesystems
> are raid mirrored, ext3, ordered-data mode.  One mirrored pair is on a
> Adaptec AHA-2940U2/W controller (actually, this is running in degraded
> mode, damn defective IBM UltraStar failed on me).  The other mirrored pair
> is on two Intel PIIX4 IDE controllers.
> 
> Since one of the raid pairs is down to a single drive, I've been backing
> it up to the other mirrored pair nightly using dump 0.4b22 and, more
> recently, dump 0.4b26.

This is due to some userspace application calling
ioctl(BLKFLSBUF);  The kernel calls invalidate_buffers()
against a live device so it can of course sometimes
encounter a locked buffer, and it spits this message.

> Any thoughts what's causing this?  Am I at risk for data loss?

No, there's no risk.  I think the invalidate_buffers()
call should only be made within the ioctl if the device's
usage count is one, but various kernel luminaries didn't
like the idea, for reasons which I failed to understand :)

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