From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 24 Jul 2020 09:47:21 +0000 (+0200)
Subject: 5.7-stable patches
X-Git-Tag: v4.14.190~40
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bb6e8bc4255e961159c28552b552a7f87fe86912;p=thirdparty%2Fkernel%2Fstable-queue.git

5.7-stable patches

added patches:
	btrfs-reloc-clear-dead_reloc_tree-bit-for-orphan-roots-to-prevent-runaway-balance.patch
---

diff --git a/queue-5.7/btrfs-reloc-clear-dead_reloc_tree-bit-for-orphan-roots-to-prevent-runaway-balance.patch b/queue-5.7/btrfs-reloc-clear-dead_reloc_tree-bit-for-orphan-roots-to-prevent-runaway-balance.patch
new file mode 100644
index 00000000000..75b2708a255
--- /dev/null
+++ b/queue-5.7/btrfs-reloc-clear-dead_reloc_tree-bit-for-orphan-roots-to-prevent-runaway-balance.patch
@@ -0,0 +1,66 @@
+From 1dae7e0e58b484eaa43d530f211098fdeeb0f404 Mon Sep 17 00:00:00 2001
+From: Qu Wenruo <wqu@suse.com>
+Date: Wed, 20 May 2020 14:58:51 +0800
+Subject: btrfs: reloc: clear DEAD_RELOC_TREE bit for orphan roots to prevent runaway balance
+
+From: Qu Wenruo <wqu@suse.com>
+
+commit 1dae7e0e58b484eaa43d530f211098fdeeb0f404 upstream.
+
+[BUG]
+There are several reported runaway balance, that balance is flooding the
+log with "found X extents" where the X never changes.
+
+[CAUSE]
+Commit d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after
+merge_reloc_roots") introduced BTRFS_ROOT_DEAD_RELOC_TREE bit to
+indicate that one subvolume has finished its tree blocks swap with its
+reloc tree.
+
+However if balance is canceled or hits ENOSPC halfway, we didn't clear
+the BTRFS_ROOT_DEAD_RELOC_TREE bit, leaving that bit hanging forever
+until unmount.
+
+Any subvolume root with that bit, would cause backref cache to skip this
+tree block, as it has finished its tree block swap.  This would cause
+all tree blocks of that root be ignored by balance, leading to runaway
+balance.
+
+[FIX]
+Fix the problem by also clearing the BTRFS_ROOT_DEAD_RELOC_TREE bit for
+the original subvolume of orphan reloc root.
+
+Add an umount check for the stale bit still set.
+
+Fixes: d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots")
+Signed-off-by: Qu Wenruo <wqu@suse.com>
+Signed-off-by: David Sterba <dsterba@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ fs/btrfs/disk-io.c    |    1 +
+ fs/btrfs/relocation.c |    2 ++
+ 2 files changed, 3 insertions(+)
+
+--- a/fs/btrfs/disk-io.c
++++ b/fs/btrfs/disk-io.c
+@@ -1998,6 +1998,7 @@ void btrfs_put_root(struct btrfs_root *r
+ 
+ 	if (refcount_dec_and_test(&root->refs)) {
+ 		WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
++		WARN_ON(test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state));
+ 		if (root->anon_dev)
+ 			free_anon_bdev(root->anon_dev);
+ 		btrfs_drew_lock_destroy(&root->snapshot_lock);
+--- a/fs/btrfs/relocation.c
++++ b/fs/btrfs/relocation.c
+@@ -2642,6 +2642,8 @@ again:
+ 					root->reloc_root = NULL;
+ 					btrfs_put_root(reloc_root);
+ 				}
++				clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE,
++					  &root->state);
+ 				btrfs_put_root(root);
+ 			}
+ 
diff --git a/queue-5.7/series b/queue-5.7/series
index e7f9cb82e24..9a301ae5b2e 100644
--- a/queue-5.7/series
+++ b/queue-5.7/series
@@ -28,3 +28,4 @@ exfat-fix-overflow-issue-in-exfat_cluster_to_sector.patch
 exfat-fix-wrong-hint_stat-initialization-in-exfat_find_dir_entry.patch
 exfat-fix-wrong-size-update-of-stream-entry-by-typo.patch
 exfat-fix-name_hash-computation-on-big-endian-systems.patch
+btrfs-reloc-clear-dead_reloc_tree-bit-for-orphan-roots-to-prevent-runaway-balance.patch