On Sun, Jun 10, 2012 at 7:19 PM, Yaniv Gardi <ygardi@xxxxxxxxxxxxxx> wrote: > First, the REQ_SECURE + REQ_DISCARD are used for specific sector/s. SANITIZE > is a generic command that erase all unmapped sectors. > Second, secure erase for a specific sector (SECURE TRIM) is no longer > supported. > > Anyhow, SANITIZE replaces the need to issue REQ_SECURE as part of the > REQ_DISCARD request. In this way DISCARD request finishes much faster (order > of magnitude) and thus improves system performance. When the NVM content > must be erased, the user may use SANITIZE to erase all unmapped sectors. SECURE is not used for all DISCARDs anyway - so that's how it works already. > > An example of usage is refurbished devices in which the carrier wants to > erase NVM content (since the user used only DISCARDs), in this case the a > SANITIZE operation will be triggered in the carrier labs from a dedicated > application through IOCTL that goes directly to the device. Note that no > change to the FS is required for such operation. > > Thanks, > Yaniv > > = > -----Original Message----- > = > From: S, Venkatraman [mailto:svenkatr@xxxxxx] > = > Sent: Friday, June 08, 2012 2:30 PM > = > To: Yaniv Gardi > = > Cc: linux-mmc@xxxxxxxxxxxxxxx; merez@xxxxxxxxxxxxxx > = > Subject: Re: [PATCH v6 0/2] *** adding and exposing SANITIZE capability > to > = > the user space via a unique IOCTL *** > = > > = > On Thu, Jun 7, 2012 at 8:08 PM, Yaniv Gardi <ygardi@xxxxxxxxxxxxxx> > = > wrote: > = > > *** adding and exposing SANITIZE capability to the user space via a > = > > unique IOCTL *** > = > > = > Well, is this really needed ? As I understand, SANITIZE is identical to > = > REQ_SECURE + REQ_DISCARD. > = > Mapping the device function to an existing attribute is more easy that > = > creating the whole plumbing around SANITIZE, just because it exists. > = > Apart from the IOCTL, it would be useful to find if any file systems > want to > = > use this, and it is any way more friendly than SECURE + DISCARD. > = > > = > > > = > > changes patch v6: > = > > fixed some code review comments > = > > added timeout dependency for CMD6 when issueing the sanitize > = > command. > = > > > = > > changes patch v5: > = > > added BUG_ON() where needed > = > > > = > > changes patch v4: > = > > removed a few debug printouts > = > > > = > > changes patch v3: > = > > split the patch into 2 commits - block and mmc/card added capability > = > > MMC_CAP2_SANITIZE to mmc controller > = > > > = > > Yaniv Gardi (2): > = > > block: ioctl support for sanitize in eMMC 4.5 > = > > mmc: card: Adding support for sanitize in eMMC 4.5 > = > > > = > > block/blk-core.c | 18 +++++++++-- > = > > block/blk-lib.c | 51 +++++++++++++++++++++++++++++++ > = > > block/blk-merge.c | 6 ++++ > = > > block/elevator.c | 41 ++++++++++++++++++++++++- > = > > block/ioctl.c | 9 +++++ > = > > drivers/mmc/card/block.c | 72 > = > > ++++++++++++++++++++++++++++++++------------ > = > > drivers/mmc/card/queue.c | 10 +++++- > = > > include/linux/blk_types.h | 5 ++- > = > > include/linux/blkdev.h | 3 ++ > = > > include/linux/fs.h | 1 + > = > > include/linux/mmc/host.h | 1 + > = > > kernel/trace/blktrace.c | 2 + > = > > 12 files changed, 191 insertions(+), 28 deletions(-) > = > > > = > > -- > = > > 1.7.6 > = > > -- > = > > Sent by a consultant of the Qualcomm Innovation Center, Inc. > = > > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora > = > > Forum > = > > -- > = > > To unsubscribe from this list: send the line "unsubscribe linux-mmc" > = > > in the body of a message to majordomo@xxxxxxxxxxxxxxx More > = > majordomo > = > > info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
