LU-13096 llite: fix potential overflow in ll_max_cached_mb_seq_write()

[fs/lustre-release.git] / lustre / llite / lproc_llite.c

diff --git a/lustre/llite/lproc_llite.c b/lustre/llite/lproc_llite.c
index 8de8299..65b6479 100644 (file)
--- a/lustre/llite/lproc_llite.c
+++ b/lustre/llite/lproc_llite.c
@@ -549,15 +549,16 @@ static ssize_t ll_max_cached_mb_seq_write(struct file *file,
 
                /* reduce LRU budget from free slots. */
                do {
-                       long ov, nv;
+                       long ov, nv, retv;
 
                        ov = atomic_long_read(&cache->ccc_lru_left);
                        if (ov == 0)
                                break;
 
                        nv = ov > diff ? ov - diff : 0;
-                       rc = atomic_long_cmpxchg(&cache->ccc_lru_left, ov, nv);
-                       if (likely(ov == rc)) {
+                       retv = atomic_long_cmpxchg(&cache->ccc_lru_left,
+                                                  ov, nv);
+                       if (likely(ov == retv)) {
                                diff -= ov - nv;
                                nrpages += ov - nv;
                                break;