Merge tag 'md-3.10' of git://neil.brown.name/md

Pull md fixes from NeilBrown:
 "A mixed bag of little fixes.  No real new functionality here.  Several
  patches are tagged for -stable."

* tag 'md-3.10' of git://neil.brown.name/md:
  MD: ignore discard request for hard disks of hybid raid1/raid10 array
  md: bad block list should default to disabled.
  md: raid1/raid10 md devices leak memory when stopping
  DM RAID: Add message/status support for changing sync action
  MD: Export 'md_reap_sync_thread' function
  md: don't update metadata when stopping a read-only array.
  md: Allow devices to be re-added to a read-only array.
  md/raid10: Allow skipping recovery when clean arrays are assembled
  MD: Fix typos in MD documentation
  md/raid5: avoid an extra write when writing to a known-bad-block.
  md/raid5: Change or of some order to improve efficiency.
  md: use set_bit_le and clear_bit_le
  md: HOT_DISK_REMOVE shouldn't make a read-auto device active.
  md: use common code for all calls to ->hot_remove_disk()
  md: never update metadata when array is read-only.

Documentation/device-mapper/dm-raid.txt

 dm-raid
--------
+=======
 
 The device-mapper RAID (dm-raid) target provides a bridge from DM to MD.
 It allows the MD RAID drivers to be accessed using a device-mapper
 interface.
 
+
+Mapping Table Interface
+-----------------------
 The target is named "raid" and it accepts the following parameters:
 
   <raid_type> <#raid_params> <raid_params> \
@@ -47,7 +50,7 @@ The target is named "raid" and it accepts the following parameters:
     followed by optional parameters (in any order):
 	[sync|nosync]   Force or prevent RAID initialization.
 
-	[rebuild <idx>]	Rebuild drive number idx (first drive is 0).
+	[rebuild <idx>]	Rebuild drive number 'idx' (first drive is 0).
 
 	[daemon_sleep <ms>]
 		Interval between runs of the bitmap daemon that
@@ -56,9 +59,9 @@ The target is named "raid" and it accepts the following parameters:
 
 	[min_recovery_rate <kB/sec/disk>]  Throttle RAID initialization
 	[max_recovery_rate <kB/sec/disk>]  Throttle RAID initialization
-	[write_mostly <idx>]		   Drive index is write-mostly
-	[max_write_behind <sectors>]       See '-write-behind=' (man mdadm)
-	[stripe_cache <sectors>]           Stripe cache size (higher RAIDs only)
+	[write_mostly <idx>]		   Mark drive index 'idx' write-mostly.
+	[max_write_behind <sectors>]       See '--write-behind=' (man mdadm)
+	[stripe_cache <sectors>]           Stripe cache size (RAID 4/5/6 only)
 	[region_size <sectors>]
 		The region_size multiplied by the number of regions is the
 		logical size of the array.  The bitmap records the device
@@ -122,7 +125,7 @@ The target is named "raid" and it accepts the following parameters:
 	given for both the metadata and data drives for a given position.
 
 
-Example tables
+Example Tables
 --------------
 # RAID4 - 4 data drives, 1 parity (no metadata devices)
 # No metadata devices specified to hold superblock/bitmap info
@@ -141,26 +144,70 @@ Example tables
         raid4 4 2048 sync min_recovery_rate 20 \
         5 8:17 8:18 8:33 8:34 8:49 8:50 8:65 8:66 8:81 8:82
 
+
+Status Output
+-------------
 'dmsetup table' displays the table used to construct the mapping.
 The optional parameters are always printed in the order listed
 above with "sync" or "nosync" always output ahead of the other
 arguments, regardless of the order used when originally loading the table.
 Arguments that can be repeated are ordered by value.
 
-'dmsetup status' yields information on the state and health of the
-array.
-The output is as follows:
+
+'dmsetup status' yields information on the state and health of the array.
+The output is as follows (normally a single line, but expanded here for
+clarity):
 1: <s> <l> raid \
-2:      <raid_type> <#devices> <1 health char for each dev> <resync_ratio>
+2:      <raid_type> <#devices> <health_chars> \
+3:      <sync_ratio> <sync_action> <mismatch_cnt>
 
 Line 1 is the standard output produced by device-mapper.
-Line 2 is produced by the raid target, and best explained by example:
-        0 1960893648 raid raid4 5 AAAAA 2/490221568
+Line 2 & 3 are produced by the raid target and are best explained by example:
+        0 1960893648 raid raid4 5 AAAAA 2/490221568 init 0
 Here we can see the RAID type is raid4, there are 5 devices - all of
-which are 'A'live, and the array is 2/490221568 complete with recovery.
-Faulty or missing devices are marked 'D'.  Devices that are out-of-sync
-are marked 'a'.
-
+which are 'A'live, and the array is 2/490221568 complete with its initial
+recovery.  Here is a fuller description of the individual fields:
+	<raid_type>     Same as the <raid_type> used to create the array.
+	<health_chars>  One char for each device, indicating: 'A' = alive and
+			in-sync, 'a' = alive but not in-sync, 'D' = dead/failed.
+	<sync_ratio>    The ratio indicating how much of the array has undergone
+			the process described by 'sync_action'.  If the
+			'sync_action' is "check" or "repair", then the process
+			of "resync" or "recover" can be considered complete.
+	<sync_action>   One of the following possible states:
+			idle    - No synchronization action is being performed.
+			frozen  - The current action has been halted.
+			resync  - Array is undergoing its initial synchronization
+				  or is resynchronizing after an unclean shutdown
+				  (possibly aided by a bitmap).
+			recover - A device in the array is being rebuilt or
+				  replaced.
+			check   - A user-initiated full check of the array is
+				  being performed.  All blocks are read and
+				  checked for consistency.  The number of
+				  discrepancies found are recorded in
+				  <mismatch_cnt>.  No changes are made to the
+				  array by this action.
+			repair  - The same as "check", but discrepancies are
+				  corrected.
+			reshape - The array is undergoing a reshape.
+	<mismatch_cnt>  The number of discrepancies found between mirror copies
+			in RAID1/10 or wrong parity values found in RAID4/5/6.
+			This value is valid only after a "check" of the array
+			is performed.  A healthy array has a 'mismatch_cnt' of 0.
+
+Message Interface
+-----------------
+The dm-raid target will accept certain actions through the 'message' interface.
+('man dmsetup' for more information on the message interface.)  These actions
+include:
+	"idle"   - Halt the current sync action.
+	"frozen" - Freeze the current sync action.
+	"resync" - Initiate/continue a resync.
+	"recover"- Initiate/continue a recover process.
+	"check"  - Initiate a check (i.e. a "scrub") of the array.
+	"repair" - Initiate a repair of the array.
+	"reshape"- Currently unsupported (-EINVAL).
 
 Version History
 ---------------
@@ -171,4 +218,7 @@ Version History
 1.3.1	Allow device replacement/rebuild for RAID 10
 1.3.2   Fix/improve redundancy checking for RAID10
 1.4.0	Non-functional change.  Removes arg from mapping function.
-1.4.1   Add RAID10 "far" and "offset" algorithm support.
+1.4.1   RAID10 fix redundancy validation checks (commit 55ebbb5).
+1.4.2   Add RAID10 "far" and "offset" algorithm support.
+1.5.0   Add message interface to allow manipulation of the sync_action.
+	New status (STATUSTYPE_INFO) fields: sync_action and mismatch_cnt.

Documentation/md.txt

@@ -119,7 +119,7 @@ device to add.
 The array is started with the RUN_ARRAY ioctl.
 
 Once started, new devices can be added.  They should have an
-appropriate superblock written to them, and then passed be in with
+appropriate superblock written to them, and then be passed in with
 ADD_NEW_DISK.
 
 Devices that have failed or are not yet active can be detached from an
@@ -131,7 +131,7 @@ Specific Rules that apply to format-0 super block arrays, and
 -------------------------------------------------------------
 
 An array can be 'created' by describing the array (level, chunksize
-etc) in a SET_ARRAY_INFO ioctl.  This must has major_version==0 and
+etc) in a SET_ARRAY_INFO ioctl.  This must have major_version==0 and
 raid_disks != 0.
 
 Then uninitialized devices can be added with ADD_NEW_DISK.  The
@@ -426,7 +426,7 @@ Each directory contains:
       offset
         This gives the location in the device (in sectors from the
         start) where data from the array will be stored.  Any part of
-        the device before this offset us not touched, unless it is
+        the device before this offset is not touched, unless it is
         used for storing metadata (Formats 1.1 and 1.2).
 
       size
@@ -440,7 +440,7 @@ Each directory contains:
         When the device is not 'in_sync', this records the number of
 	sectors from the start of the device which are known to be
 	correct.  This is normally zero, but during a recovery
-	operation is will steadily increase, and if the recovery is
+	operation it will steadily increase, and if the recovery is
 	interrupted, restoring this value can cause recovery to
 	avoid repeating the earlier blocks.  With v1.x metadata, this
 	value is saved and restored automatically.
@@ -468,7 +468,7 @@ Each directory contains:
 
 
 
-An active md device will also contain and entry for each active device
+An active md device will also contain an entry for each active device
 in the array.  These are named
 
     rdNN
@@ -482,7 +482,7 @@ will show 'in_sync' on every line.
 
 
 
-Active md devices for levels that support data redundancy (1,4,5,6)
+Active md devices for levels that support data redundancy (1,4,5,6,10)
 also have
 
    sync_action
@@ -494,7 +494,7 @@ also have
                        failed/missing device
        idle          - nothing is happening
        check         - A full check of redundancy was requested and is
-                       happening.  This reads all block and checks
+                       happening.  This reads all blocks and checks
                        them. A repair may also happen for some raid
                        levels.
        repair        - A full check and repair is happening.  This is
@@ -522,7 +522,7 @@ also have
 
    degraded
       This contains a count of the number of devices by which the
-      arrays is degraded.  So an optimal array with show '0'.  A
+      arrays is degraded.  So an optimal array will show '0'.  A
       single failed/missing drive will show '1', etc.
       This file responds to select/poll, any increase or decrease
       in the count of missing devices will trigger an event.

drivers/md/bitmap.c

@@ -846,7 +846,7 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
 	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
 		set_bit(bit, kaddr);
 	else
-		test_and_set_bit_le(bit, kaddr);
+		set_bit_le(bit, kaddr);
 	kunmap_atomic(kaddr);
 	pr_debug("set file bit %lu page %lu\n", bit, page->index);
 	/* record page number so it gets flushed to disk when unplug occurs */
@@ -868,7 +868,7 @@ static void bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
 	if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
 		clear_bit(bit, paddr);
 	else
-		test_and_clear_bit_le(bit, paddr);
+		clear_bit_le(bit, paddr);
 	kunmap_atomic(paddr);
 	if (!test_page_attr(bitmap, page->index, BITMAP_PAGE_NEEDWRITE)) {
 		set_page_attr(bitmap, page->index, BITMAP_PAGE_PENDING);

drivers/md/dm-raid.c

@@ -1279,6 +1279,31 @@ static int raid_map(struct dm_target *ti, struct bio *bio)
 	return DM_MAPIO_SUBMITTED;
 }
 
+static const char *decipher_sync_action(struct mddev *mddev)
+{
+	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
+		return "frozen";
+
+	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
+	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
+		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
+			return "reshape";
+
+		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
+			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+				return "resync";
+			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
+				return "check";
+			return "repair";
+		}
+
+		if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
+			return "recover";
+	}
+
+	return "idle";
+}
+
 static void raid_status(struct dm_target *ti, status_type_t type,
 			unsigned status_flags, char *result, unsigned maxlen)
 {
@@ -1298,8 +1323,18 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 			sync = rs->md.recovery_cp;
 
 		if (sync >= rs->md.resync_max_sectors) {
+			/*
+			 * Sync complete.
+			 */
 			array_in_sync = 1;
 			sync = rs->md.resync_max_sectors;
+		} else if (test_bit(MD_RECOVERY_REQUESTED, &rs->md.recovery)) {
+			/*
+			 * If "check" or "repair" is occurring, the array has
+			 * undergone and initial sync and the health characters
+			 * should not be 'a' anymore.
+			 */
+			array_in_sync = 1;
 		} else {
 			/*
 			 * The array may be doing an initial sync, or it may
@@ -1311,6 +1346,7 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 				if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 					array_in_sync = 1;
 		}
+
 		/*
 		 * Status characters:
 		 *  'D' = Dead/Failed device
@@ -1339,6 +1375,21 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 		       (unsigned long long) sync,
 		       (unsigned long long) rs->md.resync_max_sectors);
 
+		/*
+		 * Sync action:
+		 *   See Documentation/device-mapper/dm-raid.c for
+		 *   information on each of these states.
+		 */
+		DMEMIT(" %s", decipher_sync_action(&rs->md));
+
+		/*
+		 * resync_mismatches/mismatch_cnt
+		 *   This field shows the number of discrepancies found when
+		 *   performing a "check" of the array.
+		 */
+		DMEMIT(" %llu",
+		       (unsigned long long)
+		       atomic64_read(&rs->md.resync_mismatches));
 		break;
 	case STATUSTYPE_TABLE:
 		/* The string you would use to construct this array */
@@ -1425,7 +1476,62 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 	}
 }
 
-static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
+static int raid_message(struct dm_target *ti, unsigned argc, char **argv)
+{
+	struct raid_set *rs = ti->private;
+	struct mddev *mddev = &rs->md;
+
+	if (!strcasecmp(argv[0], "reshape")) {
+		DMERR("Reshape not supported.");
+		return -EINVAL;
+	}
+
+	if (!mddev->pers || !mddev->pers->sync_request)
+		return -EINVAL;
+
+	if (!strcasecmp(argv[0], "frozen"))
+		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+	else
+		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+
+	if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
+		if (mddev->sync_thread) {
+			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+			md_reap_sync_thread(mddev);
+		}
+	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
+		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
+		return -EBUSY;
+	else if (!strcasecmp(argv[0], "resync"))
+		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+	else if (!strcasecmp(argv[0], "recover")) {
+		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
+		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+	} else {
+		if (!strcasecmp(argv[0], "check"))
+			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
+		else if (!!strcasecmp(argv[0], "repair"))
+			return -EINVAL;
+		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
+		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
+	}
+	if (mddev->ro == 2) {
+		/* A write to sync_action is enough to justify
+		 * canceling read-auto mode
+		 */
+		mddev->ro = 0;
+		if (!mddev->suspended)
+			md_wakeup_thread(mddev->sync_thread);
+	}
+	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+	if (!mddev->suspended)
+		md_wakeup_thread(mddev->thread);
+
+	return 0;
+}
+
+static int raid_iterate_devices(struct dm_target *ti,
+				iterate_devices_callout_fn fn, void *data)
 {
 	struct raid_set *rs = ti->private;
 	unsigned i;
@@ -1482,12 +1588,13 @@ static void raid_resume(struct dm_target *ti)
 
 static struct target_type raid_target = {
 	.name = "raid",
-	.version = {1, 4, 2},
+	.version = {1, 5, 0},
 	.module = THIS_MODULE,
 	.ctr = raid_ctr,
 	.dtr = raid_dtr,
 	.map = raid_map,
 	.status = raid_status,
+	.message = raid_message,
 	.iterate_devices = raid_iterate_devices,
 	.io_hints = raid_io_hints,
 	.presuspend = raid_presuspend,

drivers/md/md.h

@@ -567,6 +567,7 @@ extern struct md_thread *md_register_thread(
 extern void md_unregister_thread(struct md_thread **threadp);
 extern void md_wakeup_thread(struct md_thread *thread);
 extern void md_check_recovery(struct mddev *mddev);
+extern void md_reap_sync_thread(struct mddev *mddev);
 extern void md_write_start(struct mddev *mddev, struct bio *bi);
 extern void md_write_end(struct mddev *mddev);
 extern void md_done_sync(struct mddev *mddev, int blocks, int ok);

drivers/md/raid1.c

@@ -981,6 +981,11 @@ static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
 	while (bio) { /* submit pending writes */
 		struct bio *next = bio->bi_next;
 		bio->bi_next = NULL;
+		if (unlikely((bio->bi_rw & REQ_DISCARD) &&
+		    !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
+			/* Just ignore it */
+			bio_endio(bio, 0);
+		else
 			generic_make_request(bio);
 		bio = next;
 	}
@@ -2901,6 +2906,7 @@ static int stop(struct mddev *mddev)
 	if (conf->r1bio_pool)
 		mempool_destroy(conf->r1bio_pool);
 	kfree(conf->mirrors);
+	safe_put_page(conf->tmppage);
 	kfree(conf->poolinfo);
 	kfree(conf);
 	mddev->private = NULL;

drivers/md/raid10.c

@@ -1133,6 +1133,11 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
 	while (bio) { /* submit pending writes */
 		struct bio *next = bio->bi_next;
 		bio->bi_next = NULL;
+		if (unlikely((bio->bi_rw & REQ_DISCARD) &&
+		    !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
+			/* Just ignore it */
+			bio_endio(bio, 0);
+		else
 			generic_make_request(bio);
 		bio = next;
 	}
@@ -2913,6 +2918,22 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
 		if (init_resync(conf))
 			return 0;
 
+	/*
+	 * Allow skipping a full rebuild for incremental assembly
+	 * of a clean array, like RAID1 does.
+	 */
+	if (mddev->bitmap == NULL &&
+	    mddev->recovery_cp == MaxSector &&
+	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
+	    conf->fullsync == 0) {
+		*skipped = 1;
+		max_sector = mddev->dev_sectors;
+		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
+		    test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
+			max_sector = mddev->resync_max_sectors;
+		return max_sector - sector_nr;
+	}
+
  skipped:
 	max_sector = mddev->dev_sectors;
 	if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
@@ -3810,6 +3831,7 @@ static int stop(struct mddev *mddev)
 
 	if (conf->r10bio_pool)
 		mempool_destroy(conf->r10bio_pool);
+	safe_put_page(conf->tmppage);
 	kfree(conf->mirrors);
 	kfree(conf);
 	mddev->private = NULL;

drivers/md/raid5.c

@@ -1887,8 +1887,15 @@ static void raid5_end_write_request(struct bio *bi, int error)
 					&rdev->mddev->recovery);
 		} else if (is_badblock(rdev, sh->sector,
 				       STRIPE_SECTORS,
-				       &first_bad, &bad_sectors))
+				       &first_bad, &bad_sectors)) {
 			set_bit(R5_MadeGood, &sh->dev[i].flags);
+			if (test_bit(R5_ReadError, &sh->dev[i].flags))
+				/* That was a successful write so make
+				 * sure it looks like we already did
+				 * a re-write.
+				 */
+				set_bit(R5_ReWrite, &sh->dev[i].flags);
+		}
 	}
 	rdev_dec_pending(rdev, conf->mddev);
 
@@ -4672,9 +4679,10 @@ static inline sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int
 		*skipped = 1;
 		return rv;
 	}
-	if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
-	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
-	    !conf->fullsync && sync_blocks >= STRIPE_SECTORS) {
+	if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
+	    !conf->fullsync &&
+	    !bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
+	    sync_blocks >= STRIPE_SECTORS) {
 		/* we can skip this block, and probably more */
 		sync_blocks /= STRIPE_SECTORS;
 		*skipped = 1;