1. Extra directory remove caching.

2. Faster inode allocation (but worse inode distribution)

lwext4/ext4.c

@@ -1167,6 +1167,9 @@ int ext4_dir_rm(const char *path)
 
     inode_current = f.inode;
     dir_end = false;
+
+    ext4_block_delay_cache_flush(mp->fs.bdev, 1);
+
     do {
         /*Load directory node.*/
         r = ext4_fs_get_inode_ref(&f.mp->fs, inode_current, &current);
@@ -1300,7 +1303,7 @@ int ext4_dir_rm(const char *path)
 
     }while(depth);
 
-
+    ext4_block_delay_cache_flush(mp->fs.bdev, 0);
     EXT4_MP_UNLOCK(mp);
     return r;
 }

lwext4/ext4_ialloc.c

@@ -186,7 +186,7 @@ int ext4_ialloc_alloc_inode(struct ext4_fs *fs, uint32_t *index, bool is_dir)
         uint32_t used_dirs = ext4_bg_get_used_dirs_count(bg, sb);
 
         /* Check if this block group is good candidate for allocation */
-        if (free_inodes >= avg_free_inodes) {
+        if (free_inodes > 0) {
             /* Load block with bitmap */
             uint32_t bitmap_block_addr = ext4_bg_get_inode_bitmap(
                     bg_ref.block_group, sb);