From: Kent Overstreet <kent.overstreet@gmail.com>
Date: Fri, 5 Aug 2022 21:08:35 +0000 (-0400)
Subject: bcachefs: Fix incorrectly freeing btree_path in alloc path
X-Git-Tag: v6.7-rc1~201^2~852
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=17047fbced563cf5abe5aa546f6a92af48900b69;p=thirdparty%2Fkernel%2Flinux.git

bcachefs: Fix incorrectly freeing btree_path in alloc path

Clearing path->preserve means the path will be dropping in
bch2_trans_begin() - but on transaction restart, we're likely to need
that path again.

This fixes a livelock in the allocation path.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
---

diff --git a/fs/bcachefs/btree_iter.h b/fs/bcachefs/btree_iter.h
index 9a3287da9a120..5ca92b6bb3977 100644
--- a/fs/bcachefs/btree_iter.h
+++ b/fs/bcachefs/btree_iter.h
@@ -335,7 +335,8 @@ void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 
 static inline void set_btree_iter_dontneed(struct btree_iter *iter)
 {
-	iter->path->preserve = false;
+	if (!iter->trans->restarted)
+		iter->path->preserve = false;
 }
 
 void *bch2_trans_kmalloc(struct btree_trans *, size_t);