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Commit 9d88883e authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[PATCH] md: teach raid5 the difference between 'check' and 'repair'. 



With this, raid5 can be asked to check parity without repairing it.  It also
keeps a count of the number of incorrect parity blocks found (mismatches) and
reports them through sysfs.

Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 24dd469d

drivers/md/md.c

+16 −2
Original line number Original line Diff line number Diff line
@@ -1758,16 +1758,29 @@ md_store_scan(mddev_t *mddev, const char *page, size_t len) 
	return len;

	return len;

}

}





static ssize_t

md_show_mismatch(mddev_t *mddev, char *page)

{

	return sprintf(page, "%llu\n",

		       (unsigned long long) mddev->resync_mismatches);

}



static struct md_sysfs_entry md_scan_mode = {

static struct md_sysfs_entry md_scan_mode = {

	.attr = {.name = "scan_mode", .mode = S_IRUGO|S_IWUSR },

	.attr = {.name = "scan_mode", .mode = S_IRUGO|S_IWUSR },

	.show = md_show_scan,

	.show = md_show_scan,

	.store = md_store_scan,

	.store = md_store_scan,

};

};





static struct md_sysfs_entry md_mismatches = {

	.attr = {.name = "mismatch_cnt", .mode = S_IRUGO },

	.show = md_show_mismatch,

};



static struct attribute *md_default_attrs[] = {

static struct attribute *md_default_attrs[] = {

	&md_level.attr,

	&md_level.attr,

	&md_raid_disks.attr,

	&md_raid_disks.attr,

	&md_scan_mode.attr,

	&md_scan_mode.attr,

	&md_mismatches.attr,

	NULL,

	NULL,

};

};
@@ -3888,12 +3901,13 @@ static void md_do_sync(mddev_t *mddev) 
		}

		}

	} while (mddev->curr_resync < 2);

	} while (mddev->curr_resync < 2);





	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))

	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {

		/* resync follows the size requested by the personality,

		/* resync follows the size requested by the personality,

		 * which defaults to physical size, but can be virtual size

		 * which defaults to physical size, but can be virtual size

		 */

		 */

		max_sectors = mddev->resync_max_sectors;

		max_sectors = mddev->resync_max_sectors;

	else

		mddev->resync_mismatches = 0;

	} else

		/* recovery follows the physical size of devices */

		/* recovery follows the physical size of devices */

		max_sectors = mddev->size << 1;

		max_sectors = mddev->size << 1;

drivers/md/raid5.c

+5 −0
Original line number Original line Diff line number Diff line
@@ -1292,6 +1292,11 @@ static void handle_stripe(struct stripe_head *sh) 
			    !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) {

			    !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) {

				/* parity is correct (on disc, not in buffer any more) */

				/* parity is correct (on disc, not in buffer any more) */

				set_bit(STRIPE_INSYNC, &sh->state);

				set_bit(STRIPE_INSYNC, &sh->state);

			} else {

				conf->mddev->resync_mismatches += STRIPE_SECTORS;

				if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))

					/* don't try to repair!! */

					set_bit(STRIPE_INSYNC, &sh->state);

			}

			}

		}

		}

		if (!test_bit(STRIPE_INSYNC, &sh->state)) {

		if (!test_bit(STRIPE_INSYNC, &sh->state)) {

include/linux/raid/md_k.h

+4 −0
Original line number Original line Diff line number Diff line
@@ -175,6 +175,10 @@ struct mddev_s 
	sector_t			resync_mark_cnt;/* blocks written at resync_mark */

	sector_t			resync_mark_cnt;/* blocks written at resync_mark */





	sector_t			resync_max_sectors; /* may be set by personality */

	sector_t			resync_max_sectors; /* may be set by personality */



	sector_t			resync_mismatches; /* count of sectors where

							    * parity/replica mismatch found

							    */

	/* recovery/resync flags 

	/* recovery/resync flags 

	 * NEEDED:   we might need to start a resync/recover

	 * NEEDED:   we might need to start a resync/recover

	 * RUNNING:  a thread is running, or about to be started

	 * RUNNING:  a thread is running, or about to be started