pkg/littlefs: fix file buffer size

examples/filesystem/Makefile

@@ -48,7 +48,7 @@ USEMODULE += constfs
 
 # Set file systems specific variables
 ifneq (,$(filter littlefs, $(USEMODULE)))
-    CFLAGS += -DVFS_FILE_BUFFER_SIZE=52 -DVFS_DIR_BUFFER_SIZE=44
+    CFLAGS += -DVFS_FILE_BUFFER_SIZE=56 -DVFS_DIR_BUFFER_SIZE=44
 else ifneq (,$(filter spiffs, $(USEMODULE)))
     SPIFFS_NB_FD ?= 8
     CFLAGS += '-DSPIFFS_FS_FD_SPACE_SIZE=(32 * $(SPIFFS_NB_FD))'

pkg/littlefs/fs/littlefs_fs.c

@@ -184,6 +184,11 @@ static int _format(vfs_mount_t *mountp)
 
 static int _mount(vfs_mount_t *mountp)
 {
+    /* if one of the lines below fail to compile you probably need to adjust
+       vfs buffer sizes ;) */
+    BUILD_BUG_ON(VFS_DIR_BUFFER_SIZE < sizeof(lfs_dir_t));
+    BUILD_BUG_ON(VFS_FILE_BUFFER_SIZE < sizeof(lfs_file_t));
+
     littlefs_desc_t *fs = mountp->private_data;
 
     DEBUG("littlefs: mount: mountp=%p\n", (void *)mountp);

sys/include/fs/littlefs_fs.h

@@ -31,14 +31,6 @@ extern "C" {
 #include "mtd.h"
 #include "mutex.h"
 
-#if VFS_FILE_BUFFER_SIZE < 52
-#error "VFS_FILE_BUFFER_SIZE is too small, at least 52 bytes is required"
-#endif
-
-#if VFS_DIR_BUFFER_SIZE < 44
-#error "VFS_DIR_BUFFER_SIZE is too small, at least 44 bytes is required"
-#endif
-
 /**
  * @name    littlefs configuration
  * @{

tests/unittests/tests-littlefs/Makefile.include

 USEMODULE += littlefs
 
 # Set vfs file and dir buffer sizes
-CFLAGS += -DVFS_FILE_BUFFER_SIZE=52 -DVFS_DIR_BUFFER_SIZE=44
+CFLAGS += -DVFS_FILE_BUFFER_SIZE=56 -DVFS_DIR_BUFFER_SIZE=44
 # Reduce LFS_NAME_MAX to 31 (as VFS_NAME_MAX default)
 CFLAGS += -DLFS_NAME_MAX=31