Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 640 insertions, 0 deletions

diff --git a/drivers/md/dm-zoned-reclaim.c b/drivers/md/dm-zoned-reclaim.c
new file mode 100644
index 000000000..9c0ecc956
--- /dev/null
+++ b/drivers/md/dm-zoned-reclaim.c
@@ -0,0 +1,640 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017 Western Digital Corporation or its affiliates.
+ *
+ * This file is released under the GPL.
+ */
+
+#include "dm-zoned.h"
+
+#include <linux/module.h>
+
+#define	DM_MSG_PREFIX		"zoned reclaim"
+
+struct dmz_reclaim {
+	struct dmz_metadata     *metadata;
+
+	struct delayed_work	work;
+	struct workqueue_struct *wq;
+
+	struct dm_kcopyd_client	*kc;
+	struct dm_kcopyd_throttle kc_throttle;
+	int			kc_err;
+
+	int			dev_idx;
+
+	unsigned long		flags;
+
+	/* Last target access time */
+	unsigned long		atime;
+};
+
+/*
+ * Reclaim state flags.
+ */
+enum {
+	DMZ_RECLAIM_KCOPY,
+};
+
+/*
+ * Number of seconds of target BIO inactivity to consider the target idle.
+ */
+#define DMZ_IDLE_PERIOD			(10UL * HZ)
+
+/*
+ * Percentage of unmapped (free) random zones below which reclaim starts
+ * even if the target is busy.
+ */
+#define DMZ_RECLAIM_LOW_UNMAP_ZONES	30
+
+/*
+ * Percentage of unmapped (free) random zones above which reclaim will
+ * stop if the target is busy.
+ */
+#define DMZ_RECLAIM_HIGH_UNMAP_ZONES	50
+
+/*
+ * Align a sequential zone write pointer to chunk_block.
+ */
+static int dmz_reclaim_align_wp(struct dmz_reclaim *zrc, struct dm_zone *zone,
+				sector_t block)
+{
+	struct dmz_metadata *zmd = zrc->metadata;
+	struct dmz_dev *dev = zone->dev;
+	sector_t wp_block = zone->wp_block;
+	unsigned int nr_blocks;
+	int ret;
+
+	if (wp_block == block)
+		return 0;
+
+	if (wp_block > block)
+		return -EIO;
+
+	/*
+	 * Zeroout the space between the write
+	 * pointer and the requested position.
+	 */
+	nr_blocks = block - wp_block;
+	ret = blkdev_issue_zeroout(dev->bdev,
+				   dmz_start_sect(zmd, zone) + dmz_blk2sect(wp_block),
+				   dmz_blk2sect(nr_blocks), GFP_NOIO, 0);
+	if (ret) {
+		dmz_dev_err(dev,
+			    "Align zone %u wp %llu to %llu (wp+%u) blocks failed %d",
+			    zone->id, (unsigned long long)wp_block,
+			    (unsigned long long)block, nr_blocks, ret);
+		dmz_check_bdev(dev);
+		return ret;
+	}
+
+	zone->wp_block = block;
+
+	return 0;
+}
+
+/*
+ * dm_kcopyd_copy end notification.
+ */
+static void dmz_reclaim_kcopy_end(int read_err, unsigned long write_err,
+				  void *context)
+{
+	struct dmz_reclaim *zrc = context;
+
+	if (read_err || write_err)
+		zrc->kc_err = -EIO;
+	else
+		zrc->kc_err = 0;
+
+	clear_bit_unlock(DMZ_RECLAIM_KCOPY, &zrc->flags);
+	smp_mb__after_atomic();
+	wake_up_bit(&zrc->flags, DMZ_RECLAIM_KCOPY);
+}
+
+/*
+ * Copy valid blocks of src_zone into dst_zone.
+ */
+static int dmz_reclaim_copy(struct dmz_reclaim *zrc,
+			    struct dm_zone *src_zone, struct dm_zone *dst_zone)
+{
+	struct dmz_metadata *zmd = zrc->metadata;
+	struct dm_io_region src, dst;
+	sector_t block = 0, end_block;
+	sector_t nr_blocks;
+	sector_t src_zone_block;
+	sector_t dst_zone_block;
+	unsigned long flags = 0;
+	int ret;
+
+	if (dmz_is_seq(src_zone))
+		end_block = src_zone->wp_block;
+	else
+		end_block = dmz_zone_nr_blocks(zmd);
+	src_zone_block = dmz_start_block(zmd, src_zone);
+	dst_zone_block = dmz_start_block(zmd, dst_zone);
+
+	if (dmz_is_seq(dst_zone))
+		set_bit(DM_KCOPYD_WRITE_SEQ, &flags);
+
+	while (block < end_block) {
+		if (src_zone->dev->flags & DMZ_BDEV_DYING)
+			return -EIO;
+		if (dst_zone->dev->flags & DMZ_BDEV_DYING)
+			return -EIO;
+
+		if (dmz_reclaim_should_terminate(src_zone))
+			return -EINTR;
+
+		/* Get a valid region from the source zone */
+		ret = dmz_first_valid_block(zmd, src_zone, &block);
+		if (ret <= 0)
+			return ret;
+		nr_blocks = ret;
+
+		/*
+		 * If we are writing in a sequential zone, we must make sure
+		 * that writes are sequential. So Zeroout any eventual hole
+		 * between writes.
+		 */
+		if (dmz_is_seq(dst_zone)) {
+			ret = dmz_reclaim_align_wp(zrc, dst_zone, block);
+			if (ret)
+				return ret;
+		}
+
+		src.bdev = src_zone->dev->bdev;
+		src.sector = dmz_blk2sect(src_zone_block + block);
+		src.count = dmz_blk2sect(nr_blocks);
+
+		dst.bdev = dst_zone->dev->bdev;
+		dst.sector = dmz_blk2sect(dst_zone_block + block);
+		dst.count = src.count;
+
+		/* Copy the valid region */
+		set_bit(DMZ_RECLAIM_KCOPY, &zrc->flags);
+		dm_kcopyd_copy(zrc->kc, &src, 1, &dst, flags,
+			       dmz_reclaim_kcopy_end, zrc);
+
+		/* Wait for copy to complete */
+		wait_on_bit_io(&zrc->flags, DMZ_RECLAIM_KCOPY,
+			       TASK_UNINTERRUPTIBLE);
+		if (zrc->kc_err)
+			return zrc->kc_err;
+
+		block += nr_blocks;
+		if (dmz_is_seq(dst_zone))
+			dst_zone->wp_block = block;
+	}
+
+	return 0;
+}
+
+/*
+ * Move valid blocks of dzone buffer zone into dzone (after its write pointer)
+ * and free the buffer zone.
+ */
+static int dmz_reclaim_buf(struct dmz_reclaim *zrc, struct dm_zone *dzone)
+{
+	struct dm_zone *bzone = dzone->bzone;
+	sector_t chunk_block = dzone->wp_block;
+	struct dmz_metadata *zmd = zrc->metadata;
+	int ret;
+
+	DMDEBUG("(%s/%u): Chunk %u, move buf zone %u (weight %u) to data zone %u (weight %u)",
+		dmz_metadata_label(zmd), zrc->dev_idx,
+		dzone->chunk, bzone->id, dmz_weight(bzone),
+		dzone->id, dmz_weight(dzone));
+
+	/* Flush data zone into the buffer zone */
+	ret = dmz_reclaim_copy(zrc, bzone, dzone);
+	if (ret < 0)
+		return ret;
+
+	dmz_lock_flush(zmd);
+
+	/* Validate copied blocks */
+	ret = dmz_merge_valid_blocks(zmd, bzone, dzone, chunk_block);
+	if (ret == 0) {
+		/* Free the buffer zone */
+		dmz_invalidate_blocks(zmd, bzone, 0, dmz_zone_nr_blocks(zmd));
+		dmz_lock_map(zmd);
+		dmz_unmap_zone(zmd, bzone);
+		dmz_unlock_zone_reclaim(dzone);
+		dmz_free_zone(zmd, bzone);
+		dmz_unlock_map(zmd);
+	}
+
+	dmz_unlock_flush(zmd);
+
+	return ret;
+}
+
+/*
+ * Merge valid blocks of dzone into its buffer zone and free dzone.
+ */
+static int dmz_reclaim_seq_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
+{
+	unsigned int chunk = dzone->chunk;
+	struct dm_zone *bzone = dzone->bzone;
+	struct dmz_metadata *zmd = zrc->metadata;
+	int ret = 0;
+
+	DMDEBUG("(%s/%u): Chunk %u, move data zone %u (weight %u) to buf zone %u (weight %u)",
+		dmz_metadata_label(zmd), zrc->dev_idx,
+		chunk, dzone->id, dmz_weight(dzone),
+		bzone->id, dmz_weight(bzone));
+
+	/* Flush data zone into the buffer zone */
+	ret = dmz_reclaim_copy(zrc, dzone, bzone);
+	if (ret < 0)
+		return ret;
+
+	dmz_lock_flush(zmd);
+
+	/* Validate copied blocks */
+	ret = dmz_merge_valid_blocks(zmd, dzone, bzone, 0);
+	if (ret == 0) {
+		/*
+		 * Free the data zone and remap the chunk to
+		 * the buffer zone.
+		 */
+		dmz_invalidate_blocks(zmd, dzone, 0, dmz_zone_nr_blocks(zmd));
+		dmz_lock_map(zmd);
+		dmz_unmap_zone(zmd, bzone);
+		dmz_unmap_zone(zmd, dzone);
+		dmz_unlock_zone_reclaim(dzone);
+		dmz_free_zone(zmd, dzone);
+		dmz_map_zone(zmd, bzone, chunk);
+		dmz_unlock_map(zmd);
+	}
+
+	dmz_unlock_flush(zmd);
+
+	return ret;
+}
+
+/*
+ * Move valid blocks of the random data zone dzone into a free sequential zone.
+ * Once blocks are moved, remap the zone chunk to the sequential zone.
+ */
+static int dmz_reclaim_rnd_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
+{
+	unsigned int chunk = dzone->chunk;
+	struct dm_zone *szone = NULL;
+	struct dmz_metadata *zmd = zrc->metadata;
+	int ret;
+	int alloc_flags = DMZ_ALLOC_SEQ;
+
+	/* Get a free random or sequential zone */
+	dmz_lock_map(zmd);
+again:
+	szone = dmz_alloc_zone(zmd, zrc->dev_idx,
+			       alloc_flags | DMZ_ALLOC_RECLAIM);
+	if (!szone && alloc_flags == DMZ_ALLOC_SEQ && dmz_nr_cache_zones(zmd)) {
+		alloc_flags = DMZ_ALLOC_RND;
+		goto again;
+	}
+	dmz_unlock_map(zmd);
+	if (!szone)
+		return -ENOSPC;
+
+	DMDEBUG("(%s/%u): Chunk %u, move %s zone %u (weight %u) to %s zone %u",
+		dmz_metadata_label(zmd), zrc->dev_idx, chunk,
+		dmz_is_cache(dzone) ? "cache" : "rnd",
+		dzone->id, dmz_weight(dzone),
+		dmz_is_rnd(szone) ? "rnd" : "seq", szone->id);
+
+	/* Flush the random data zone into the sequential zone */
+	ret = dmz_reclaim_copy(zrc, dzone, szone);
+
+	dmz_lock_flush(zmd);
+
+	if (ret == 0) {
+		/* Validate copied blocks */
+		ret = dmz_copy_valid_blocks(zmd, dzone, szone);
+	}
+	if (ret) {
+		/* Free the sequential zone */
+		dmz_lock_map(zmd);
+		dmz_free_zone(zmd, szone);
+		dmz_unlock_map(zmd);
+	} else {
+		/* Free the data zone and remap the chunk */
+		dmz_invalidate_blocks(zmd, dzone, 0, dmz_zone_nr_blocks(zmd));
+		dmz_lock_map(zmd);
+		dmz_unmap_zone(zmd, dzone);
+		dmz_unlock_zone_reclaim(dzone);
+		dmz_free_zone(zmd, dzone);
+		dmz_map_zone(zmd, szone, chunk);
+		dmz_unlock_map(zmd);
+	}
+
+	dmz_unlock_flush(zmd);
+
+	return ret;
+}
+
+/*
+ * Reclaim an empty zone.
+ */
+static void dmz_reclaim_empty(struct dmz_reclaim *zrc, struct dm_zone *dzone)
+{
+	struct dmz_metadata *zmd = zrc->metadata;
+
+	dmz_lock_flush(zmd);
+	dmz_lock_map(zmd);
+	dmz_unmap_zone(zmd, dzone);
+	dmz_unlock_zone_reclaim(dzone);
+	dmz_free_zone(zmd, dzone);
+	dmz_unlock_map(zmd);
+	dmz_unlock_flush(zmd);
+}
+
+/*
+ * Test if the target device is idle.
+ */
+static inline int dmz_target_idle(struct dmz_reclaim *zrc)
+{
+	return time_is_before_jiffies(zrc->atime + DMZ_IDLE_PERIOD);
+}
+
+/*
+ * Find a candidate zone for reclaim and process it.
+ */
+static int dmz_do_reclaim(struct dmz_reclaim *zrc)
+{
+	struct dmz_metadata *zmd = zrc->metadata;
+	struct dm_zone *dzone;
+	struct dm_zone *rzone;
+	unsigned long start;
+	int ret;
+
+	/* Get a data zone */
+	dzone = dmz_get_zone_for_reclaim(zmd, zrc->dev_idx,
+					 dmz_target_idle(zrc));
+	if (!dzone) {
+		DMDEBUG("(%s/%u): No zone found to reclaim",
+			dmz_metadata_label(zmd), zrc->dev_idx);
+		return -EBUSY;
+	}
+	rzone = dzone;
+
+	start = jiffies;
+	if (dmz_is_cache(dzone) || dmz_is_rnd(dzone)) {
+		if (!dmz_weight(dzone)) {
+			/* Empty zone */
+			dmz_reclaim_empty(zrc, dzone);
+			ret = 0;
+		} else {
+			/*
+			 * Reclaim the random data zone by moving its
+			 * valid data blocks to a free sequential zone.
+			 */
+			ret = dmz_reclaim_rnd_data(zrc, dzone);
+		}
+	} else {
+		struct dm_zone *bzone = dzone->bzone;
+		sector_t chunk_block = 0;
+
+		ret = dmz_first_valid_block(zmd, bzone, &chunk_block);
+		if (ret < 0)
+			goto out;
+
+		if (ret == 0 || chunk_block >= dzone->wp_block) {
+			/*
+			 * The buffer zone is empty or its valid blocks are
+			 * after the data zone write pointer.
+			 */
+			ret = dmz_reclaim_buf(zrc, dzone);
+			rzone = bzone;
+		} else {
+			/*
+			 * Reclaim the data zone by merging it into the
+			 * buffer zone so that the buffer zone itself can
+			 * be later reclaimed.
+			 */
+			ret = dmz_reclaim_seq_data(zrc, dzone);
+		}
+	}
+out:
+	if (ret) {
+		if (ret == -EINTR)
+			DMDEBUG("(%s/%u): reclaim zone %u interrupted",
+				dmz_metadata_label(zmd), zrc->dev_idx,
+				rzone->id);
+		else
+			DMDEBUG("(%s/%u): Failed to reclaim zone %u, err %d",
+				dmz_metadata_label(zmd), zrc->dev_idx,
+				rzone->id, ret);
+		dmz_unlock_zone_reclaim(dzone);
+		return ret;
+	}
+
+	ret = dmz_flush_metadata(zrc->metadata);
+	if (ret) {
+		DMDEBUG("(%s/%u): Metadata flush for zone %u failed, err %d",
+			dmz_metadata_label(zmd), zrc->dev_idx, rzone->id, ret);
+		return ret;
+	}
+
+	DMDEBUG("(%s/%u): Reclaimed zone %u in %u ms",
+		dmz_metadata_label(zmd), zrc->dev_idx,
+		rzone->id, jiffies_to_msecs(jiffies - start));
+	return 0;
+}
+
+static unsigned int dmz_reclaim_percentage(struct dmz_reclaim *zrc)
+{
+	struct dmz_metadata *zmd = zrc->metadata;
+	unsigned int nr_cache = dmz_nr_cache_zones(zmd);
+	unsigned int nr_unmap, nr_zones;
+
+	if (nr_cache) {
+		nr_zones = nr_cache;
+		nr_unmap = dmz_nr_unmap_cache_zones(zmd);
+	} else {
+		nr_zones = dmz_nr_rnd_zones(zmd, zrc->dev_idx);
+		nr_unmap = dmz_nr_unmap_rnd_zones(zmd, zrc->dev_idx);
+	}
+	if (nr_unmap <= 1)
+		return 0;
+	return nr_unmap * 100 / nr_zones;
+}
+
+/*
+ * Test if reclaim is necessary.
+ */
+static bool dmz_should_reclaim(struct dmz_reclaim *zrc, unsigned int p_unmap)
+{
+	unsigned int nr_reclaim;
+
+	nr_reclaim = dmz_nr_rnd_zones(zrc->metadata, zrc->dev_idx);
+
+	if (dmz_nr_cache_zones(zrc->metadata)) {
+		/*
+		 * The first device in a multi-device
+		 * setup only contains cache zones, so
+		 * never start reclaim there.
+		 */
+		if (zrc->dev_idx == 0)
+			return false;
+		nr_reclaim += dmz_nr_cache_zones(zrc->metadata);
+	}
+
+	/* Reclaim when idle */
+	if (dmz_target_idle(zrc) && nr_reclaim)
+		return true;
+
+	/* If there are still plenty of cache zones, do not reclaim */
+	if (p_unmap >= DMZ_RECLAIM_HIGH_UNMAP_ZONES)
+		return false;
+
+	/*
+	 * If the percentage of unmapped cache zones is low,
+	 * reclaim even if the target is busy.
+	 */
+	return p_unmap <= DMZ_RECLAIM_LOW_UNMAP_ZONES;
+}
+
+/*
+ * Reclaim work function.
+ */
+static void dmz_reclaim_work(struct work_struct *work)
+{
+	struct dmz_reclaim *zrc = container_of(work, struct dmz_reclaim, work.work);
+	struct dmz_metadata *zmd = zrc->metadata;
+	unsigned int p_unmap;
+	int ret;
+
+	if (dmz_dev_is_dying(zmd))
+		return;
+
+	p_unmap = dmz_reclaim_percentage(zrc);
+	if (!dmz_should_reclaim(zrc, p_unmap)) {
+		mod_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD);
+		return;
+	}
+
+	/*
+	 * We need to start reclaiming random zones: set up zone copy
+	 * throttling to either go fast if we are very low on random zones
+	 * and slower if there are still some free random zones to avoid
+	 * as much as possible to negatively impact the user workload.
+	 */
+	if (dmz_target_idle(zrc) || p_unmap < DMZ_RECLAIM_LOW_UNMAP_ZONES / 2) {
+		/* Idle or very low percentage: go fast */
+		zrc->kc_throttle.throttle = 100;
+	} else {
+		/* Busy but we still have some random zone: throttle */
+		zrc->kc_throttle.throttle = min(75U, 100U - p_unmap / 2);
+	}
+
+	DMDEBUG("(%s/%u): Reclaim (%u): %s, %u%% free zones (%u/%u cache %u/%u random)",
+		dmz_metadata_label(zmd), zrc->dev_idx,
+		zrc->kc_throttle.throttle,
+		(dmz_target_idle(zrc) ? "Idle" : "Busy"),
+		p_unmap, dmz_nr_unmap_cache_zones(zmd),
+		dmz_nr_cache_zones(zmd),
+		dmz_nr_unmap_rnd_zones(zmd, zrc->dev_idx),
+		dmz_nr_rnd_zones(zmd, zrc->dev_idx));
+
+	ret = dmz_do_reclaim(zrc);
+	if (ret && ret != -EINTR) {
+		if (!dmz_check_dev(zmd))
+			return;
+	}
+
+	dmz_schedule_reclaim(zrc);
+}
+
+/*
+ * Initialize reclaim.
+ */
+int dmz_ctr_reclaim(struct dmz_metadata *zmd,
+		    struct dmz_reclaim **reclaim, int idx)
+{
+	struct dmz_reclaim *zrc;
+	int ret;
+
+	zrc = kzalloc(sizeof(struct dmz_reclaim), GFP_KERNEL);
+	if (!zrc)
+		return -ENOMEM;
+
+	zrc->metadata = zmd;
+	zrc->atime = jiffies;
+	zrc->dev_idx = idx;
+
+	/* Reclaim kcopyd client */
+	zrc->kc = dm_kcopyd_client_create(&zrc->kc_throttle);
+	if (IS_ERR(zrc->kc)) {
+		ret = PTR_ERR(zrc->kc);
+		zrc->kc = NULL;
+		goto err;
+	}
+
+	/* Reclaim work */
+	INIT_DELAYED_WORK(&zrc->work, dmz_reclaim_work);
+	zrc->wq = alloc_ordered_workqueue("dmz_rwq_%s_%d", WQ_MEM_RECLAIM,
+					  dmz_metadata_label(zmd), idx);
+	if (!zrc->wq) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	*reclaim = zrc;
+	queue_delayed_work(zrc->wq, &zrc->work, 0);
+
+	return 0;
+err:
+	if (zrc->kc)
+		dm_kcopyd_client_destroy(zrc->kc);
+	kfree(zrc);
+
+	return ret;
+}
+
+/*
+ * Terminate reclaim.
+ */
+void dmz_dtr_reclaim(struct dmz_reclaim *zrc)
+{
+	cancel_delayed_work_sync(&zrc->work);
+	destroy_workqueue(zrc->wq);
+	dm_kcopyd_client_destroy(zrc->kc);
+	kfree(zrc);
+}
+
+/*
+ * Suspend reclaim.
+ */
+void dmz_suspend_reclaim(struct dmz_reclaim *zrc)
+{
+	cancel_delayed_work_sync(&zrc->work);
+}
+
+/*
+ * Resume reclaim.
+ */
+void dmz_resume_reclaim(struct dmz_reclaim *zrc)
+{
+	queue_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD);
+}
+
+/*
+ * BIO accounting.
+ */
+void dmz_reclaim_bio_acc(struct dmz_reclaim *zrc)
+{
+	zrc->atime = jiffies;
+}
+
+/*
+ * Start reclaim if necessary.
+ */
+void dmz_schedule_reclaim(struct dmz_reclaim *zrc)
+{
+	unsigned int p_unmap = dmz_reclaim_percentage(zrc);
+
+	if (dmz_should_reclaim(zrc, p_unmap))
+		mod_delayed_work(zrc->wq, &zrc->work, 0);
+}