Fixed issue with big-endian CTZ lists intertwined in commit logic

Found while testing big-endian support. Basically, if littlefs is really
really unlucky, the block allocator could kick in while committing a
file's CTZ reference. If this happens, the block allocator will need to
traverse all CTZ skip-lists in memory, including the skip-list we're
committing. This means we can't convert the CTZ's endianness in place,
and need to make a copy on big-endian systems.

We rely on dead-code elimination from the compiler to make the
conditional behaviour for big-endian vs little-endian system a noop
determined by the lfs_tole32 intrinsic.

1 files changed, 11 insertions, 11 deletions

diff --git a/lfs_util.h b/lfs_util.h
index 80b4002..8a65694 100644
--- a/lfs_util.h
+++ b/lfs_util.h
@@ -11,8 +11,8 @@
 // LFS_CONFIG as a header file to include (-DLFS_CONFIG=lfs_config.h).
 //
 // If LFS_CONFIG is used, none of the default utils will be emitted and must be
-// provided by the config file. To start I would suggest copying lfs_util.h and
-// modifying as needed.
+// provided by the config file. To start, I would suggest copying lfs_util.h
+// and modifying as needed.
 #ifdef LFS_CONFIG
 #define LFS_STRINGIZE(x) LFS_STRINGIZE2(x)
 #define LFS_STRINGIZE2(x) #x
@@ -88,6 +88,15 @@ static inline uint32_t lfs_min(uint32_t a, uint32_t b) {
     return (a < b) ? a : b;
 }
 
+// Align to nearest multiple of a size
+static inline uint32_t lfs_aligndown(uint32_t a, uint32_t alignment) {
+    return a - (a % alignment);
+}
+
+static inline uint32_t lfs_alignup(uint32_t a, uint32_t alignment) {
+    return lfs_aligndown(a + alignment-1, alignment);
+}
+
 // Find the next smallest power of 2 less than or equal to a
 static inline uint32_t lfs_npw2(uint32_t a) {
 #if !defined(LFS_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM))
@@ -177,15 +186,6 @@ static inline uint16_t lfs_tole16(uint16_t a) {
     return lfs_fromle16(a);
 }
 
-// Align to nearest multiple of a size
-static inline uint32_t lfs_aligndown(uint32_t a, uint32_t alignment) {
-    return a - (a % alignment);
-}
-
-static inline uint32_t lfs_alignup(uint32_t a, uint32_t alignment) {
-    return lfs_aligndown(a + alignment-1, alignment);
-}
-
 // Calculate CRC-32 with polynomial = 0x04c11db7
 uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size);