Assert on NULL IO functions

littlefs-project · Dec 9, 2024 · 32d9fcd · 32d9fcd
1 parent 2fcecc8
commit 32d9fcd
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/lfs.c b/lfs.c
@@ -4236,6 +4236,14 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     LFS_ASSERT(4*lfs_npw2(0xffffffff / (lfs->cfg->block_size-2*4))
             <= lfs->cfg->block_size);
 
+    // check that the user has provided io functions correctly.
+    LFS_ASSERT(lfs->cfg->read != NULL);
+#ifndef LFS_READONLY
+    LFS_ASSERT(lfs->cfg->prog != NULL);
+    LFS_ASSERT(lfs->cfg->erase != NULL);
+    LFS_ASSERT(lfs->cfg->sync != NULL);
+#endif
+
     // block_cycles = 0 is no longer supported.
     //
     // block_cycles is the number of erase cycles before littlefs evicts