Commit c4a39551 authored by Jonathan Brassow's avatar Jonathan Brassow Committed by NeilBrown
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MD: Remember the last sync operation that was performed 



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: default avatarJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent eea136d6

Documentation/device-mapper/dm-raid.txt

+1 −0
Original line number Diff line number Diff line
@@ -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".

drivers/md/dm-raid.c

+2 −1
Original line number Diff line number Diff line
@@ -1388,6 +1388,7 @@ static void raid_status(struct dm_target *ti, status_type_t type, 
		 *   performing a "check" of the array.

		 */

		DMEMIT(" %llu",

		       (strcmp(rs->md.last_sync_action, "check")) ? 0 :

		       (unsigned long long)

		       atomic64_read(&rs->md.resync_mismatches));

		break;
@@ -1651,7 +1652,7 @@ static void raid_resume(struct dm_target *ti) 


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,

drivers/md/md.c

+21 −8
Original line number Diff line number Diff line
@@ -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 char *page, size_t len) 
	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, char *page) 
		       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_attrs[] = { 


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,
@@ -7329,7 +7338,7 @@ void md_do_sync(struct md_thread *thread) 
	sector_t last_check;

	int skipped = 0;

	struct md_rdev *rdev;

	char *desc;

	char *desc, *action = NULL;

	struct blk_plug plug;



	/* just incase thread restarts... */
@@ -7339,17 +7348,21 @@ void md_do_sync(struct md_thread *thread) 
		return;



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

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

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

			desc = "data-check";

		else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))

			action = "check";

		} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {

			desc = "requested-resync";

		else

			action = "repair";

		} else

			desc = "resync";

	} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))

		desc = "reshape";

	else

		desc = "recovery";



	mddev->last_sync_action = 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

drivers/md/md.h

+8 −0
Original line number Diff line number Diff line
@@ -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

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