MD: Remember the last sync operation that was performed
This patch adds a field to the mddev structure to track the last
sync operation that was performed. This is especially useful when
it comes to what is recorded in mismatch_cnt in sysfs. If the
last operation was "data-check", then it reports the number of
descrepancies found by the user-initiated check. If it was a
"repair" operation, then it is reporting the number of
descrepancies repaired. etc.
Signed-off-by: Jonathan Brassow <jbrassow@xxxxxxxxxx>
Index: linux-upstream/drivers/md/dm-raid.c
===================================================================
--- linux-upstream.orig/drivers/md/dm-raid.c
+++ linux-upstream/drivers/md/dm-raid.c
@@ -1388,6 +1388,7 @@ static void raid_status(struct dm_target
* performing a "check" of the array.
*/
DMEMIT(" %llu",
+ (strcmp(rs->md.last_sync_action, "data-check")) ? 0 :
(unsigned long long)
atomic64_read(&rs->md.resync_mismatches));
break;
@@ -1651,7 +1652,7 @@ static void raid_resume(struct dm_target
static struct target_type raid_target = {
.name = "raid",
- .version = {1, 5, 1},
+ .version = {1, 5, 2},
.module = THIS_MODULE,
.ctr = raid_ctr,
.dtr = raid_dtr,
Index: linux-upstream/drivers/md/md.c
===================================================================
--- linux-upstream.orig/drivers/md/md.c
+++ linux-upstream/drivers/md/md.c
@@ -521,6 +521,7 @@ void mddev_init(struct mddev *mddev)
init_waitqueue_head(&mddev->recovery_wait);
mddev->reshape_position = MaxSector;
mddev->reshape_backwards = 0;
+ mddev->last_sync_action = "none";
mddev->resync_min = 0;
mddev->resync_max = MaxSector;
mddev->level = LEVEL_NONE;
@@ -4272,6 +4273,17 @@ action_store(struct mddev *mddev, const
return len;
}
+static struct md_sysfs_entry md_scan_mode =
+__ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
+
+static ssize_t
+last_sync_action_show(struct mddev *mddev, char *page)
+{
+ return sprintf(page, "%s\n", mddev->last_sync_action);
+}
+
+static struct md_sysfs_entry md_last_scan_mode = __ATTR_RO(last_sync_action);
+
static ssize_t
mismatch_cnt_show(struct mddev *mddev, char *page)
{
@@ -4280,10 +4292,6 @@ mismatch_cnt_show(struct mddev *mddev, c
atomic64_read(&mddev->resync_mismatches));
}
-static struct md_sysfs_entry md_scan_mode =
-__ATTR(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
-
-
static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
static ssize_t
@@ -4686,6 +4694,7 @@ static struct attribute *md_default_attr
static struct attribute *md_redundancy_attrs[] = {
&md_scan_mode.attr,
+ &md_last_scan_mode.attr,
&md_mismatches.attr,
&md_sync_min.attr,
&md_sync_max.attr,
@@ -7336,7 +7345,7 @@ void md_do_sync(struct md_thread *thread
if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
desc = "data-check";
else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
- desc = "requested-resync";
+ desc = "requested-resync"; /* AKA "repair" */
else
desc = "resync";
} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
@@ -7344,6 +7353,8 @@ void md_do_sync(struct md_thread *thread
else
desc = "recovery";
+ mddev->last_sync_action = desc;
+
/* we overload curr_resync somewhat here.
* 0 == not engaged in resync at all
* 2 == checking that there is no conflict with another sync
Index: linux-upstream/drivers/md/md.h
===================================================================
--- linux-upstream.orig/drivers/md/md.h
+++ linux-upstream/drivers/md/md.h
@@ -268,6 +268,14 @@ struct mddev {
struct md_thread *thread; /* management thread */
struct md_thread *sync_thread; /* doing resync or reconstruct */
+
+ /* 'last_sync_action' is initialized to "none". It is set when a
+ * sync operation (i.e "data-check", "requested-resync", "resync",
+ * "recovery", or "reshape") is started. It holds this value even
+ * when the sync thread is "frozen" (interrupted) or "idle" (stopped
+ * or finished). It is overwritten when a new sync operation is begun.
+ */
+ char *last_sync_action;
sector_t curr_resync; /* last block scheduled */
/* As resync requests can complete out of order, we cannot easily track
* how much resync has been completed. So we occasionally pause until
Index: linux-upstream/Documentation/device-mapper/dm-raid.txt
===================================================================
--- linux-upstream.orig/Documentation/device-mapper/dm-raid.txt
+++ linux-upstream/Documentation/device-mapper/dm-raid.txt
@@ -223,3 +223,4 @@ Version History
1.5.0 Add message interface to allow manipulation of the sync_action.
New status (STATUSTYPE_INFO) fields: sync_action and mismatch_cnt.
1.5.1 Add ability to restore transiently failed devices on resume.
+1.5.2 'mismatch_cnt' is zero unless [last_]sync_action is "check".
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