[dm-devel] Is it deliberate that the device mapper is not passing the DISCARD ioctls

[Lukas Czerner]

On Mon, 20 Sep 2010, Theodore Ts'o wrote:

> Hi there,
> 
> I was just testing discard support in mke2fs, and I was surprised that
> although the dm layer appears to pass discard requests through to the
> underlying block device driver when submitted through the bio layer
> (i.e., from kernel file systems), apparently the discard ioctls (i.e.,
> BLKDISCARD, BLKDISCARDSEC, BLKDISCARDZEROES) are not currently wired up
> in the dm layer.
> 
> Is this deliberate, or an oversight?
> 
> Thanks, regards,

Hi Ted,

I have tested this with 2.6.35 and it really did not work for me as
well, but with 2.6.36-rc5 (latests kernel) it works just fine. Though,
not sure when it was added. But according to the log it seems it was
merged in with 8357422d4bf33bc2c35884d4016c3fc9efbbc1d2.

-Lukas

> 
> 					- Ted
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