dm raid: add raid4/5/6 journal write-back support via journal_mode option (6e53636f) · Commits · 戴 / test

Documentation/device-mapper/dm-raid.txt

+10 −1

Original line number	Diff line number	Diff line
		@@ -170,6 +170,13 @@ The target is named "raid" and it accepts the following parameters:
		Takeover/reshape is not possible with a raid4/5/6 journal device;
		it has to be deconfigured before requesting these.

		[journal_mode <mode>]
		This option sets the caching mode on journaled raid4/5/6 raid sets
		(see 'journal_dev <dev>' above) to 'writethrough' or 'writeback'.
		If 'writeback' is selected the journal device has to be resilient
		and must not suffer from the 'write hole' problem itself (e.g. use
		raid1 or raid10) to avoid a single point of failure.

		<#raid_devs>: The number of devices composing the array.
		Each device consists of two entries. The first is the device
		containing the metadata (if any); the second is the one containing the
		@@ -254,7 +261,8 @@ recovery. Here is a fuller description of the individual fields:
		<data_offset> The current data offset to the start of the user data on
		each component device of a raid set (see the respective
		raid parameter to support out-of-place reshaping).
		<journal_char> 'A' - active raid4/5/6 journal device.
		<journal_char> 'A' - active write-through journal device.
		'a' - active write-back journal device.
		'D' - dead journal device.
		'-' - no journal device.

		@@ -334,3 +342,4 @@ Version History
		1.10.1 Fix data corruption on reshape request
		1.11.0 Fix table line argument order
		(wrong raid10_copies/raid10_format sequence)
		1.11.1 Add raid4/5/6 journal write-back support via journal_mode option

drivers/md/dm-raid.c

+91 −13

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2010-2011 Neil Brown
		* Copyright (C) 2010-2016 Red Hat, Inc. All rights reserved.
		* Copyright (C) 2010-2017 Red Hat, Inc. All rights reserved.
		*
		* This file is released under the GPL.
		*/
		@@ -79,7 +79,10 @@ struct raid_dev {
		#define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 / / Only with raid10! */

		/* New for v1.10.0 */
		#define __CTR_FLAG_JOURNAL_DEV 15 /* 2 / / Only with raid4/5/6! */
		#define __CTR_FLAG_JOURNAL_DEV 15 /* 2 / / Only with raid4/5/6 (journal device)! */

		/* New for v1.11.1 */
		#define __CTR_FLAG_JOURNAL_MODE 16 /* 2 / / Only with raid4/5/6 (journal mode)! */

		/*
		* Flags for rs->ctr_flags field.
		@@ -100,6 +103,7 @@ struct raid_dev {
		#define CTR_FLAG_DATA_OFFSET (1 << __CTR_FLAG_DATA_OFFSET)
		#define CTR_FLAG_RAID10_USE_NEAR_SETS (1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
		#define CTR_FLAG_JOURNAL_DEV (1 << __CTR_FLAG_JOURNAL_DEV)
		#define CTR_FLAG_JOURNAL_MODE (1 << __CTR_FLAG_JOURNAL_MODE)

		#define RESUME_STAY_FROZEN_FLAGS (CTR_FLAG_DELTA_DISKS \| CTR_FLAG_DATA_OFFSET)

		@@ -175,7 +179,8 @@ struct raid_dev {
		CTR_FLAG_REGION_SIZE \| \
		CTR_FLAG_DELTA_DISKS \| \
		CTR_FLAG_DATA_OFFSET \| \
		CTR_FLAG_JOURNAL_DEV)
		CTR_FLAG_JOURNAL_DEV \| \
		CTR_FLAG_JOURNAL_MODE)

		#define RAID6_VALID_FLAGS (CTR_FLAG_SYNC \| \
		CTR_FLAG_REBUILD \| \
		@@ -186,7 +191,8 @@ struct raid_dev {
		CTR_FLAG_REGION_SIZE \| \
		CTR_FLAG_DELTA_DISKS \| \
		CTR_FLAG_DATA_OFFSET \| \
		CTR_FLAG_JOURNAL_DEV)
		CTR_FLAG_JOURNAL_DEV \| \
		CTR_FLAG_JOURNAL_MODE)
		/* ...valid options definitions per raid level */

		/*
		@@ -239,6 +245,7 @@ struct raid_set {
		struct journal_dev {
		struct dm_dev *dev;
		struct md_rdev rdev;
		int mode;
		} journal_dev;

		struct raid_dev dev[0];
		@@ -326,6 +333,7 @@ static struct arg_name_flag {
		{ CTR_FLAG_DELTA_DISKS, "delta_disks"},
		{ CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
		{ CTR_FLAG_JOURNAL_DEV, "journal_dev" },
		{ CTR_FLAG_JOURNAL_MODE, "journal_mode" },
		};

		/* Return argument name string for given @flag */
		@@ -344,6 +352,39 @@ static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
		return NULL;
		}

		/* Define correlation of raid456 journal cache modes and dm-raid target line parameters */
		static struct {
		const int mode;
		const char *param;
		} _raid456_journal_mode[] = {
		{ R5C_JOURNAL_MODE_WRITE_THROUGH , "writethrough" },
		{ R5C_JOURNAL_MODE_WRITE_BACK , "writeback" }
		};

		/* Return MD raid4/5/6 journal mode for dm @journal_mode one */
		static int dm_raid_journal_mode_to_md(const char *mode)
		{
		int m = ARRAY_SIZE(_raid456_journal_mode);

		while (m--)
		if (!strcasecmp(mode, _raid456_journal_mode[m].param))
		return _raid456_journal_mode[m].mode;

		return -EINVAL;
		}

		/* Return dm-raid raid4/5/6 journal mode string for @mode */
		static const char *md_journal_mode_to_dm_raid(const int mode)
		{
		int m = ARRAY_SIZE(_raid456_journal_mode);

		while (m--)
		if (mode == _raid456_journal_mode[m].mode)
		return _raid456_journal_mode[m].param;

		return "unknown";
		}

		/*
		* Bool helpers to test for various raid levels of a raid set.
		* It's level as reported by the superblock rather than
		@@ -1183,7 +1224,7 @@ static int parse_raid_params(struct raid_set rs, struct dm_arg_set as,
		continue;
		}

		/* "journal_dev dev" */
		/* "journal_dev <dev>" */
		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV))) {
		int r;
		struct md_rdev *jdev;
		@@ -1211,10 +1252,32 @@ static int parse_raid_params(struct raid_set rs, struct dm_arg_set as,
		rs->ti->error = "No space for raid4/5/6 journal";
		return -ENOSPC;
		}
		rs->journal_dev.mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
		set_bit(Journal, &jdev->flags);
		continue;
		}

		/* "journal_mode <mode>" ("journal_dev" mandatory!) */
		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE))) {
		int r;

		if (!test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
		rs->ti->error = "raid4/5/6 'journal_mode' is invalid without 'journal_dev'";
		return -EINVAL;
		}
		if (test_and_set_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
		rs->ti->error = "Only one raid4/5/6 'journal_mode' argument allowed";
		return -EINVAL;
		}
		r = dm_raid_journal_mode_to_md(arg);
		if (r < 0) {
		rs->ti->error = "Invalid 'journal_mode' argument";
		return r;
		}
		rs->journal_dev.mode = r;
		continue;
		}

		/*
		* Parameters with number values from here on.
		*/
		@@ -3076,6 +3139,16 @@ static int raid_ctr(struct dm_target ti, unsigned int argc, char *argv)
		rs->callbacks.congested_fn = raid_is_congested;
		dm_table_add_target_callbacks(ti->table, &rs->callbacks);

		/* If raid4/5/6 journal mode explictely requested (only possible with journal dev) -> set it */
		if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
		r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
		if (r) {
		ti->error = "Failed to set raid4/5/6 journal mode";
		mddev_unlock(&rs->md);
		goto bad_journal_mode_set;
		}
		}

		mddev_suspend(&rs->md);

		/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
		@@ -3109,6 +3182,7 @@ static int raid_ctr(struct dm_target ti, unsigned int argc, char *argv)
		mddev_unlock(&rs->md);
		return 0;

		bad_journal_mode_set:
		bad_stripe_cache:
		bad_check_reshape:
		md_stop(&rs->md);
		@@ -3180,18 +3254,18 @@ static const char decipher_sync_action(struct mddev mddev)
		* Status characters:
		*
		* 'D' = Dead/Failed raid set component or raid4/5/6 journal device
		* 'a' = Alive but not in-sync
		* 'A' = Alive and in-sync raid set component or alive raid4/5/6 journal device
		* 'a' = Alive but not in-sync raid set component _or_ alive raid4/5/6 'write_back' journal device
		* 'A' = Alive and in-sync raid set component _or_ alive raid4/5/6 'write_through' journal device
		* '-' = Non-existing device (i.e. uspace passed '- -' into the ctr)
		*/
		static const char __raid_dev_status(struct md_rdev rdev, bool array_in_sync)
		static const char __raid_dev_status(struct raid_set rs, struct md_rdev *rdev, bool array_in_sync)
		{
		if (!rdev->bdev)
		return "-";
		else if (test_bit(Faulty, &rdev->flags))
		return "D";
		else if (test_bit(Journal, &rdev->flags))
		return "A";
		return (rs->journal_dev.mode == R5C_JOURNAL_MODE_WRITE_THROUGH) ? "A" : "a";
		else if (!array_in_sync \|\| !test_bit(In_sync, &rdev->flags))
		return "a";
		else
		@@ -3315,7 +3389,7 @@ static void raid_status(struct dm_target *ti, status_type_t type,

		/* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
		for (i = 0; i < rs->raid_disks; i++)
		DMEMIT(__raid_dev_status(&rs->dev[i].rdev, array_in_sync));
		DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev, array_in_sync));

		/*
		* In-sync/Reshape ratio:
		@@ -3366,7 +3440,7 @@ static void raid_status(struct dm_target *ti, status_type_t type,
		* v1.10.0+:
		*/
		DMEMIT(" %s", test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ?
		__raid_dev_status(&rs->journal_dev.rdev, 0) : "-");
		__raid_dev_status(rs, &rs->journal_dev.rdev, 0) : "-");
		break;

		case STATUSTYPE_TABLE:
		@@ -3381,7 +3455,8 @@ static void raid_status(struct dm_target *ti, status_type_t type,
		write_mostly_params +
		hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
		hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2 +
		(test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ? 2 : 0);
		(test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ? 2 : 0) +
		(test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags) ? 2 : 0);

		/* Emit table line */
		/* This has to be in the documented order for userspace! */
		@@ -3433,6 +3508,9 @@ static void raid_status(struct dm_target *ti, status_type_t type,
		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags))
		DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV),
		__get_dev_name(rs->journal_dev.dev));
		if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags))
		DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE),
		md_journal_mode_to_dm_raid(rs->journal_dev.mode));
		DMEMIT(" %d", rs->raid_disks);
		for (i = 0; i < rs->raid_disks; i++)
		DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
		@@ -3793,7 +3871,7 @@ static void raid_resume(struct dm_target *ti)

		static struct target_type raid_target = {
		.name = "raid",
		.version = {1, 11, 0},
		.version = {1, 11, 1},
		.module = THIS_MODULE,
		.ctr = raid_ctr,
		.dtr = raid_dtr,

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