[PATCH] erofs: fix missing folio_unlock causing lock imbalance

[Zhan Xusheng]

folio_trylock() in erofs_try_to_free_all_cached_folios() may
successfully acquire the folio lock, but the subsequent check
for erofs_folio_is_managed() can skip unlocking when the folio
is not managed by EROFS.

This leads to a lock imbalance and leaves the folio permanently
locked, which may cause reclaim stalls or interfere with memory
management.

Fix this by ensuring folio_unlock() is called before continuing.

Signed-off-by: Zhan Xusheng <zhanxusheng@xxxxxxxxxx>
---
 fs/erofs/zdata.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index fe8121df9ef2..9d7ff22f1622 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -605,8 +605,10 @@ static int erofs_try_to_free_all_cached_folios(struct erofs_sb_info *sbi,
 			if (!folio_trylock(folio))
 				return -EBUSY;
 
-			if (!erofs_folio_is_managed(sbi, folio))
+			if (!erofs_folio_is_managed(sbi, folio)) {
+				folio_unlock(folio);
 				continue;
+			}
 			pcl->compressed_bvecs[i].page = NULL;
 			folio_detach_private(folio);
 			folio_unlock(folio);
-- 
2.43.0