[PATCH v2 1/3] erofs: correct the remaining shrink objects

[Gao Xiang]

The remaining count should not include successful
shrink attempts.

Fixes: e7e9a307be9d ("staging: erofs: introduce workstation for decompression")
Cc: <stable at vger.kernel.org> # 4.19+
Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---

Changes since v1:
 - Add "Fixes:" tags respectively suggested by Eric. I'd suggest
   no rush to backport PATCH 2/3 and 3/3 since it's not quite
   sure whether they behave well for normal images for now and
   I will backport them manually later since they have no impact
   on system stability with corrupted images;

 - Fix PATCH 2/3 to exclude legacy (no decompression inplace
   support, < v5.3) images.

 fs/erofs/utils.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index fddc5059c930..df42ea552a44 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -286,7 +286,7 @@ static unsigned long erofs_shrink_scan(struct shrinker *shrink,
 		spin_unlock(&erofs_sb_list_lock);
 		sbi->shrinker_run_no = run_no;
 
-		freed += erofs_shrink_workstation(sbi, nr);
+		freed += erofs_shrink_workstation(sbi, nr - freed);
 
 		spin_lock(&erofs_sb_list_lock);
 		/* Get the next list element before we move this one */
-- 
2.17.1