[PATCH v1 8/9] ntfs: only count successfully cleared runs when freeing clusters

[Baolin Liu]

From: Baolin Liu <liubaolin@xxxxxxxxxx>

ntfs_cluster_free_from_rl_nolock() adds a run's length to nr_freed
whenever the error bookkeeping condition is false, which includes
cases where ntfs_bitmap_clear_run() actually failed - e.g. a second
run failing with the same errno as an earlier one, or any failure
after a non-ENOMEM error was already recorded. Since a failed
ntfs_bitmap_clear_run() rolls back its partial modifications, no
bits were cleared for that run, yet its length still inflates
vol->free_clusters, corrupting statfs output and the allocator's
free space gate.

Only count runs whose bitmap clear succeeded.

Fixes: 11ccc9107dc4 ("ntfs: update runlist handling and cluster allocator")
Signed-off-by: Baolin Liu <liubaolin@xxxxxxxxxx>
---
 fs/ntfs/lcnalloc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c
index aa2e017a4384..795f71d26895 100644
--- a/fs/ntfs/lcnalloc.c
+++ b/fs/ntfs/lcnalloc.c
@@ -53,10 +53,10 @@ int ntfs_cluster_free_from_rl_nolock(struct ntfs_volume *vol,
 		if (rl->lcn < 0)
 			continue;
 		err = ntfs_bitmap_clear_run(lcnbmp_vi, rl->lcn, rl->length);
-		if (unlikely(err && (!ret || ret == -ENOMEM) && ret != err))
-			ret = err;
-		else
+		if (likely(!err))
 			nr_freed += rl->length;
+		else if (!ret || ret == -ENOMEM)
+			ret = err;
 	}
 	ntfs_inc_free_clusters(vol, nr_freed);
 	ntfs_debug("Done.");
-- 
2.51.0