On Tue, Sep 21, 2010 at 6:42 AM, Lukas Czerner <lczerner@xxxxxxxxxx> wrote: > 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. Makes sense, DM's discard support was added during the 2.6.36 merge window. Mike -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel