Re: [PATCH V2 0/4] Add MMC erase and secure erase

From: Adrian Hunter
Date: Mon Jun 14 2010 - 07:10:43 EST

Christoph Hellwig wrote:
On Sun, Jun 13, 2010 at 01:01:34PM +0300, Adrian Hunter wrote:

Add ability to do MMC erase and secure erase operations from userspace,
using the BLKDISCARD ioctl and a newly created BLKSECDISCARD ioctl.

Have you done any measurement if the use of the block layer changes
performance of the discard requests for you?

No. For my purposes there will be only 1 discard request for the entire
device which will take several minutes to process, so block layer
performance is not a factor.

I'd really prefer to
send down the secure erase that way, too. This could easily be done
by having a DISCARD_SECURE rw flag, which just ORs another flag into
the request type field.

Needs a bio flag, a request flag, setup the request flag based on the
bio flag, prevent merging secure and non-secure discards, prevent drivers
doing non-secure discards for secure discards.

Seems like a lot of little changes for something that no one wants.
Shouldn't it wait for someone to need it first?
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at