bcachefs: fix eytzinger0_find_gt()

- fix return types: promoting from unsigned to ssize_t does not do what
  we want here, and was pointless since the rest of the eytzinger code
  is u32
- nr, not size

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/eytzinger.h b/fs/bcachefs/eytzinger.h
index ee0e2df33322d2dccb60e1ed90257863769ead0d..24840aee335c0ffeabd3ad69c79665cc005e28d8 100644 (file)
--- a/fs/bcachefs/eytzinger.h
+++ b/fs/bcachefs/eytzinger.h
@@ -242,8 +242,8 @@ static inline unsigned inorder_to_eytzinger0(unsigned i, unsigned size)
             (_i) = eytzinger0_next((_i), (_size)))
 
 /* return greatest node <= @search, or -1 if not found */
-static inline ssize_t eytzinger0_find_le(void *base, size_t nr, size_t size,
-                                        cmp_func_t cmp, const void *search)
+static inline int eytzinger0_find_le(void *base, size_t nr, size_t size,
+                                    cmp_func_t cmp, const void *search)
 {
        unsigned i, n = 0;
 
@@ -256,18 +256,32 @@ static inline ssize_t eytzinger0_find_le(void *base, size_t nr, size_t size,
        } while (n < nr);
 
        if (n & 1) {
-               /* @i was greater than @search, return previous node: */
+               /*
+                * @i was greater than @search, return previous node:
+                *
+                * if @i was leftmost/smallest element,
+                * eytzinger0_prev(eytzinger0_first())) returns -1, as expected
+                */
                return eytzinger0_prev(i, nr);
        } else {
                return i;
        }
 }
 
-static inline ssize_t eytzinger0_find_gt(void *base, size_t nr, size_t size,
-                                        cmp_func_t cmp, const void *search)
+static inline int eytzinger0_find_gt(void *base, size_t nr, size_t size,
+                                    cmp_func_t cmp, const void *search)
 {
        ssize_t idx = eytzinger0_find_le(base, nr, size, cmp, search);
-       return eytzinger0_next(idx, size);
+
+       /*
+        * if eytitzinger0_find_le() returned -1 - no element was <= search - we
+        * want to return the first element; next/prev identities mean this work
+        * as expected
+        *
+        * similarly if find_le() returns last element, we should return -1;
+        * identities mean this all works out:
+        */
+       return eytzinger0_next(idx, nr);
 }
 
 #define eytzinger0_find(base, nr, size, _cmp, search)                  \