From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: [PATCH] md: Add support for data integrity to MD Date: Wed, 24 Sep 2008 12:46:08 +1000 Message-ID: <18649.43504.157272.351801@notabene.brown> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from Martin K. Petersen on Saturday September 20 Sender: linux-kernel-owner@vger.kernel.org To: "Martin K. Petersen" Cc: jens.axboe@oracle.com, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org List-Id: linux-raid.ids On Saturday September 20, martin.petersen@oracle.com wrote: > > If all subdevices support the same protection format the MD device is > flagged as capable. But what if we subsequently add a different device to that array which uses a different protection format. Would we be able to tell the filesystem that integrity protection isn't available any more? Or can we detect if the filesystem is using integrity protection, and reject the new device if it doesn't match? In either case, some extra handling is needed in bind_rdev_to_array. NeilBrown > > Depends on d7533ad0e132f92e75c1b2eb7c26387b25a583c1 being reverted. > > Signed-off-by: Martin K. Petersen > --- > drivers/md/md.c | 32 +++++++++++++++++++++++++++++++- > 1 files changed, 31 insertions(+), 1 deletions(-) > > diff --git a/drivers/md/md.c b/drivers/md/md.c > index 45521da..b038581 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -3497,7 +3497,7 @@ static int do_md_run(mddev_t * mddev) > int err; > int chunk_size; > struct list_head *tmp; > - mdk_rdev_t *rdev; > + mdk_rdev_t *rdev, *prev; > struct gendisk *disk; > struct mdk_personality *pers; > char b[BDEVNAME_SIZE]; > @@ -3759,6 +3759,35 @@ static int do_md_run(mddev_t * mddev) > sysfs_notify(&mddev->kobj, NULL, "sync_action"); > sysfs_notify(&mddev->kobj, NULL, "degraded"); > kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE); > + > + /* Data integrity passthrough not supported on RAID 4, 5 and 6 */ > + if (pers->level >= 4 && pers->level <= 6) > + return 0; > + > + prev = NULL; > + > + rdev_for_each(rdev, tmp, mddev) { > + > + if (prev && blk_integrity_compare(prev->bdev, rdev->bdev) < 0) { > + printk(KERN_ERR "%s: %s %s Integrity mismatch!\n", > + __func__, prev->bdev->bd_disk->disk_name, > + rdev->bdev->bd_disk->disk_name); > + return 0; > + } > + > + prev = rdev; > + } > + > + if (prev && bdev_get_integrity(prev->bdev)) { > + > + if (blk_integrity_register(disk, prev->bdev->bd_disk->integrity)) > + printk(KERN_ERR "%s: %s Could not register integrity!\n", > + __func__, disk->disk_name); > + else > + printk(KERN_INFO "Enabling data integrity on %s\n", > + disk->disk_name); > + } > + > return 0; > } > > @@ -3947,6 +3976,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open) > printk(KERN_INFO "md: %s switched to read-only mode.\n", > mdname(mddev)); > err = 0; > + blk_integrity_unregister(disk); > md_new_event(mddev); > sysfs_notify(&mddev->kobj, NULL, "array_state"); > out: > -- > 1.5.5.1 > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html