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FAILED: patch "[PATCH] btrfs: zoned: print unusable percentage when reclaiming block" failed to apply to 5.13-stable tree

PATCH [email protected] 1 participant 1 message Jul 19, 2021

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The patch below does not apply to the 5.13-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5f93e776c6734cea989aeb4f2d6c97e521baa683 Mon Sep 17 00:00:00 2001
From: Johannes Thumshirn <[email protected]>
Date: Tue, 29 Jun 2021 03:16:46 +0900
Subject: [PATCH] btrfs: zoned: print unusable percentage when reclaiming block
groups

When we're automatically reclaiming a zone, because its zone_unusable value is above the reclaim threshold, we're only logging how much percent of the zone's capacity are used, but not how much of the capacity is unusable.

Also print the percentage of the unusable space in the block group before we're reclaiming it.

Example:

BTRFS info (device sdg): reclaiming chunk 230686720 with 13% used 86% unusable

CC [email protected] # 5.13
Signed-off-by Johannes Thumshirn <[email protected]>
Reviewed-by David Sterba <[email protected]>
Signed-off-by David Sterba <[email protected]>
fs/btrfs/block-group.c +12 -2
index d4c8dc550889..fec7a34b27f3 100644
@@ -1501,6 +1501,7 @@ void btrfs_reclaim_bgs_work(struct work_struct *work)
 	mutex_lock(&fs_info->reclaim_bgs_lock);
 	spin_lock(&fs_info->unused_bgs_lock);
 	while (!list_empty(&fs_info->reclaim_bgs)) {
+		u64 zone_unusable;
 		int ret = 0;
 
 		bg = list_first_entry(&fs_info->reclaim_bgs,

@@ -1534,13 +1535,22 @@ void btrfs_reclaim_bgs_work(struct work_struct *work)
 			goto next;
 		}
 
+		/*
+		 * Cache the zone_unusable value before turning the block group
+		 * to read only. As soon as the blog group is read only it's
+		 * zone_unusable value gets moved to the block group's read-only
+		 * bytes and isn't available for calculations anymore.
+		 */
+		zone_unusable = bg->zone_unusable;
 		ret = inc_block_group_ro(bg, 0);
 		up_write(&space_info->groups_sem);
 		if (ret < 0)
 			goto next;
 
-		btrfs_info(fs_info, "reclaiming chunk %llu with %llu%% used",
-				bg->start, div64_u64(bg->used * 100, bg->length));
+		btrfs_info(fs_info,
+			"reclaiming chunk %llu with %llu%% used %llu%% unusable",
+				bg->start, div_u64(bg->used * 100, bg->length),
+				div64_u64(zone_unusable * 100, bg->length));
 		trace_btrfs_reclaim_block_group(bg);
 		ret = btrfs_relocate_chunk(fs_info, bg->start);
 		if (ret)