From 9d88883e68f404d5581bd391713ceef470ea53a9 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 8 Nov 2005 21:39:26 -0800 Subject: [PATCH] [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: Neil Brown Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/md.c | 18 ++++++++++++++++-- drivers/md/raid5.c | 5 +++++ include/linux/raid/md_k.h | 4 ++++ 3 files changed, 25 insertions(+), 2 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 37400873b87..e58d61d9f31 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1758,16 +1758,29 @@ md_store_scan(mddev_t *mddev, const char *page, size_t 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 = { .attr = {.name = "scan_mode", .mode = S_IRUGO|S_IWUSR }, .show = md_show_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[] = { &md_level.attr, &md_raid_disks.attr, &md_scan_mode.attr, + &md_mismatches.attr, NULL, }; @@ -3888,12 +3901,13 @@ static void md_do_sync(mddev_t *mddev) } } 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, * which defaults to physical size, but can be virtual size */ max_sectors = mddev->resync_max_sectors; - else + mddev->resync_mismatches = 0; + } else /* recovery follows the physical size of devices */ max_sectors = mddev->size << 1; diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 121fbaa9ed5..ce154553aca 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1292,6 +1292,11 @@ static void handle_stripe(struct stripe_head *sh) !memcmp(pagea, pagea+4, STRIPE_SIZE-4)) { /* parity is correct (on disc, not in buffer any more) */ 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)) { diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h index efd04dca0ab..cb8b44d1588 100644 --- a/include/linux/raid/md_k.h +++ b/include/linux/raid/md_k.h @@ -175,6 +175,10 @@ struct mddev_s sector_t resync_mark_cnt;/* blocks written at resync_mark */ 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 * NEEDED: we might need to start a resync/recover * RUNNING: a thread is running, or about to be started -- 2.20.1