Add 'ppl' and 'no-ppl' options for --update=

This can be used with --assemble for super1 and with --update-subarray
for imsm to enable or disable PPL in the metadata.

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@gmail.com>

Assemble.c

@@ -602,6 +602,12 @@ static int load_devices(struct devs *devices, char *devmap,
 			if (strcmp(c->update, "uuid") == 0 && !ident->uuid_set)
 				random_uuid((__u8 *)ident->uuid);
 
+			if (strcmp(c->update, "ppl") == 0 &&
+			    ident->bitmap_fd >= 0) {
+				pr_err("PPL is not compatible with bitmap\n");
+				return -1;
+			}
+
 			dfd = dev_open(devname,
 				       tmpdev->disposition == 'I'
 				       ? O_RDWR : (O_RDWR|O_EXCL));

mdadm.8.in

@@ -1176,6 +1176,8 @@ argument given to this flag can be one of
 .BR no\-bitmap ,
 .BR bbl ,
 .BR no\-bbl ,
+.BR ppl ,
+.BR no\-ppl ,
 .BR metadata ,
 or
 .BR super\-minor .
@@ -1316,6 +1318,16 @@ option will cause any reservation of space for a bad block list to be
 removed.  If the bad block list contains entries, this will fail, as
 removing the list could cause data corruption.
 
+The
+.B ppl
+option will enable PPL for a RAID5 array and reserve space for PPL on each
+device. There must be enough free space between the data and superblock and a
+write-intent bitmap or journal must not be used.
+
+The
+.B no\-ppl
+option will disable PPL in the superblock.
+
 .TP
 .BR \-\-freeze\-reshape
 Option is intended to be used in start-up scripts during initrd boot phase.
@@ -2327,9 +2339,11 @@ superblock field in the subarray.  Similar to updating an array in
 .B \-U
 or
 .B \-\-update=
-option.  Currently only
-.B name
-is supported.
+option. The supported options are
+.BR name ,
+.B ppl
+and
+.BR no\-ppl .
 
 The
 .B name
@@ -2340,6 +2354,13 @@ re\-assembled.  If updating
 would change the UUID of an active subarray this operation is blocked,
 and the command will end in an error.
 
+The
+.B ppl
+and
+.B no\-ppl
+options enable and disable PPL in the metadata. Currently supported only for
+IMSM subarrays.
+
 .TP
 .B \-\-examine
 The device should be a component of an md array.

mdadm.c

@@ -769,6 +769,10 @@ int main(int argc, char *argv[])
 				continue;
 			if (strcmp(c.update, "force-no-bbl") == 0)
 				continue;
+			if (strcmp(c.update, "ppl") == 0)
+				continue;
+			if (strcmp(c.update, "no-ppl") == 0)
+				continue;
 			if (strcmp(c.update, "metadata") == 0)
 				continue;
 			if (strcmp(c.update, "revert-reshape") == 0)
@@ -802,7 +806,7 @@ int main(int argc, char *argv[])
 		"     'sparc2.2', 'super-minor', 'uuid', 'name', 'nodes', 'resync',\n"
 		"     'summaries', 'homehost', 'home-cluster', 'byteorder', 'devicesize',\n"
 		"     'no-bitmap', 'metadata', 'revert-reshape'\n"
-		"     'bbl', 'no-bbl', 'force-no-bbl'\n"
+		"     'bbl', 'no-bbl', 'force-no-bbl', 'ppl', 'no-ppl'\n"
 				);
 			exit(outf == stdout ? 0 : 2);
 

super-intel.c

@@ -451,6 +451,7 @@ enum imsm_update_type {
 	update_general_migration_checkpoint,
 	update_size_change,
 	update_prealloc_badblocks_mem,
+	update_rwh_policy,
 };
 
 struct imsm_update_activate_spare {
@@ -543,6 +544,12 @@ struct imsm_update_prealloc_bb_mem {
 	enum imsm_update_type type;
 };
 
+struct imsm_update_rwh_policy {
+	enum imsm_update_type type;
+	int new_policy;
+	int dev_idx;
+};
+
 static const char *_sys_dev_type[] = {
 	[SYS_DEV_UNKNOWN] = "Unknown",
 	[SYS_DEV_SAS] = "SAS",
@@ -7373,6 +7380,34 @@ static int update_subarray_imsm(struct supertype *st, char *subarray,
 			}
 			super->updates_pending++;
 		}
+	} else if (strcmp(update, "ppl") == 0 ||
+		   strcmp(update, "no-ppl") == 0) {
+		int new_policy;
+		char *ep;
+		int vol = strtoul(subarray, &ep, 10);
+
+		if (*ep != '\0' || vol >= super->anchor->num_raid_devs)
+			return 2;
+
+		if (strcmp(update, "ppl") == 0)
+			new_policy = RWH_DISTRIBUTED;
+		else
+			new_policy = RWH_OFF;
+
+		if (st->update_tail) {
+			struct imsm_update_rwh_policy *u = xmalloc(sizeof(*u));
+
+			u->type = update_rwh_policy;
+			u->dev_idx = vol;
+			u->new_policy = new_policy;
+			append_metadata_update(st, u, sizeof(*u));
+		} else {
+			struct imsm_dev *dev;
+
+			dev = get_imsm_dev(super, vol);
+			dev->rwh_policy = new_policy;
+			super->updates_pending++;
+		}
 	} else
 		return 2;
 
@@ -9599,6 +9634,21 @@ static void imsm_process_update(struct supertype *st,
 	}
 	case update_prealloc_badblocks_mem:
 		break;
+	case update_rwh_policy: {
+		struct imsm_update_rwh_policy *u = (void *)update->buf;
+		int target = u->dev_idx;
+		struct imsm_dev *dev = get_imsm_dev(super, target);
+		if (!dev) {
+			dprintf("could not find subarray-%d\n", target);
+			break;
+		}
+
+		if (dev->rwh_policy != u->new_policy) {
+			dev->rwh_policy = u->new_policy;
+			super->updates_pending++;
+		}
+		break;
+	}
 	default:
 		pr_err("error: unsuported process update type:(type: %d)\n",	type);
 	}
@@ -9844,6 +9894,11 @@ static int imsm_prepare_update(struct supertype *st,
 		super->extra_space += sizeof(struct bbm_log) -
 			get_imsm_bbm_log_size(super->bbm_log);
 		break;
+	case update_rwh_policy: {
+		if (update->len < (int)sizeof(struct imsm_update_rwh_policy))
+			return 0;
+		break;
+	}
 	default:
 		return 0;
 	}

super1.c

@@ -1325,6 +1325,55 @@ static int update_super1(struct supertype *st, struct mdinfo *info,
 		sb->bblog_size = 0;
 		sb->bblog_shift = 0;
 		sb->bblog_offset = 0;
+	} else if (strcmp(update, "ppl") == 0) {
+		unsigned long long sb_offset = __le64_to_cpu(sb->super_offset);
+		unsigned long long data_offset = __le64_to_cpu(sb->data_offset);
+		unsigned long long data_size = __le64_to_cpu(sb->data_size);
+		long bb_offset = __le32_to_cpu(sb->bblog_offset);
+		int space;
+		int optimal_space;
+		int offset;
+
+		if (sb->feature_map & __cpu_to_le32(MD_FEATURE_BITMAP_OFFSET)) {
+			pr_err("Cannot add PPL to array with bitmap\n");
+			return -2;
+		}
+
+		if (sb->feature_map & __cpu_to_le32(MD_FEATURE_JOURNAL)) {
+			pr_err("Cannot add PPL to array with journal\n");
+			return -2;
+		}
+
+		if (sb_offset < data_offset) {
+			if (bb_offset)
+				space = bb_offset - 8;
+			else
+				space = data_offset - sb_offset - 8;
+			offset = 8;
+		} else {
+			offset = -(sb_offset - data_offset - data_size);
+			if (offset < INT16_MIN)
+				offset = INT16_MIN;
+			space = -(offset - bb_offset);
+		}
+
+		if (space < (PPL_HEADER_SIZE >> 9) + 8) {
+			pr_err("Not enough space to add ppl\n");
+			return -2;
+		}
+
+		optimal_space = choose_ppl_space(__le32_to_cpu(sb->chunksize));
+
+		if (space > optimal_space)
+			space = optimal_space;
+		if (space > UINT16_MAX)
+			space = UINT16_MAX;
+
+		sb->ppl.offset = __cpu_to_le16(offset);
+		sb->ppl.size = __cpu_to_le16(space);
+		sb->feature_map |= __cpu_to_le32(MD_FEATURE_PPL);
+	} else if (strcmp(update, "no-ppl") == 0) {
+		sb->feature_map &= ~ __cpu_to_le32(MD_FEATURE_PPL);
 	} else if (strcmp(update, "name") == 0) {
 		if (info->name[0] == 0)
 			sprintf(info->name, "%d", info->array.md_minor);