Modified entry head to include name length

This provides a path for adding inlined files in the future, which
requires multiple lengths to distinguish between the file data and name.

As an extra bonus, the directory can now be iterated over even if the
types are unknown, since the name's representation is consistent on all
entry types.

This does come at the cost of reducing types from 16-bits to 8-bits, but
I doubt this will become a problem.

lfs.c

@@ -711,9 +711,9 @@ static int lfs_dir_find(lfs_t *lfs, lfs_dir_t *dir,
                 return err;
             }
 
-            if (((0xff & entry->d.type) != LFS_TYPE_REG &&
+            if ((entry->d.type != LFS_TYPE_REG &&
-                 (0xff & entry->d.type) != LFS_TYPE_DIR) ||
+                 entry->d.type != LFS_TYPE_DIR) ||
-                entry->d.len - sizeof(entry->d) != pathlen) {
+                entry->d.name != pathlen) {
                 continue;
             }
 
@@ -784,7 +784,8 @@ int lfs_mkdir(lfs_t *lfs, const char *path) {
     }
 
     entry.d.type = LFS_TYPE_DIR;
-    entry.d.len = sizeof(entry.d) + strlen(path);
+    entry.d.name = strlen(path);
+    entry.d.len = sizeof(entry.d) + entry.d.name;
     entry.d.u.dir[0] = dir.pair[0];
     entry.d.u.dir[1] = dir.pair[1];
 
@@ -868,19 +869,19 @@ int lfs_dir_read(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info) {
             return (err == LFS_ERR_NOENT) ? 0 : err;
         }
 
-        if ((0xff & entry.d.type) == LFS_TYPE_REG ||
+        if (entry.d.type == LFS_TYPE_REG ||
-            (0xff & entry.d.type) == LFS_TYPE_DIR) {
+            entry.d.type == LFS_TYPE_DIR) {
             break;
         }
     }
 
-    info->type = entry.d.type & 0xff;
+    info->type = entry.d.type;
     if (info->type == LFS_TYPE_REG) {
         info->size = entry.d.u.file.size;
     }
 
     int err = lfs_bd_read(lfs, dir->pair[0], entry.off + sizeof(entry.d),
-            info->name, entry.d.len - sizeof(entry.d));
+            info->name, entry.d.name);
     if (err) {
         return err;
     }
@@ -1116,7 +1117,8 @@ int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
 
         // create entry to remember name
         entry.d.type = LFS_TYPE_REG;
-        entry.d.len = sizeof(entry.d) + strlen(path);
+        entry.d.name = strlen(path);
+        entry.d.len = sizeof(entry.d) + entry.d.name;
         entry.d.u.file.head = -1;
         entry.d.u.file.size = 0;
         err = lfs_dir_append(lfs, &cwd, &entry, path);
@@ -1530,13 +1532,13 @@ int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info) {
     }
 
     memset(info, 0, sizeof(*info));
-    info->type = entry.d.type & 0xff;
+    info->type = entry.d.type;
     if (info->type == LFS_TYPE_REG) {
         info->size = entry.d.u.file.size;
     }
 
     err = lfs_bd_read(lfs, cwd.pair[0], entry.off + sizeof(entry.d),
-            info->name, entry.d.len - sizeof(entry.d));
+            info->name, entry.d.name);
     if (err) {
         return err;
     }
@@ -1649,7 +1651,8 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
     // move to new location
     lfs_entry_t newentry = preventry;
     newentry.d = oldentry.d;
-    newentry.d.len = sizeof(newentry.d) + strlen(newpath);
+    newentry.d.name = strlen(newpath);
+    newentry.d.len = sizeof(newentry.d) + newentry.d.name;
 
     if (prevexists) {
         int err = lfs_dir_update(lfs, &newcwd, &newentry, newpath);
@@ -1806,8 +1809,9 @@ int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
     lfs_superblock_t superblock = {
         .off = sizeof(superdir.d),
         .d.type = LFS_TYPE_SUPERBLOCK,
+        .d.name = sizeof(superblock.d.magic),
         .d.len = sizeof(superblock.d),
-        .d.version = 0x00000001,
+        .d.version = 0x00010001,
         .d.magic = {"littlefs"},
         .d.block_size  = lfs->cfg->block_size,
         .d.block_count = lfs->cfg->block_count,
@@ -1874,7 +1878,7 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
         return LFS_ERR_CORRUPT;
     }
 
-    if (superblock.d.version > 0x0000ffff) {
+    if (superblock.d.version > (0x00010001 | 0x0000ffff)) {
         LFS_ERROR("Invalid version %d.%d\n",
                 0xffff & (superblock.d.version >> 16),
                 0xffff & (superblock.d.version >> 0));
@@ -1922,7 +1926,7 @@ int lfs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data) {
             }
 
             dir.off += entry.d.len;
-            if ((0xf & entry.d.type) == LFS_TYPE_REG) {
+            if ((0xf & entry.d.type) == (0xf & LFS_TYPE_REG)) {
                 int err = lfs_index_traverse(lfs, &lfs->rcache, NULL,
                         entry.d.u.file.head, entry.d.u.file.size, cb, data);
                 if (err) {
@@ -2012,7 +2016,7 @@ static int lfs_parent(lfs_t *lfs, const lfs_block_t dir[2],
                 break;
             }
 
-            if (((0xf & entry->d.type) == LFS_TYPE_DIR) && 
+            if (((0xf & entry->d.type) == (0xf & LFS_TYPE_DIR)) &&
                  lfs_paircmp(entry->d.u.dir, dir) == 0) {
                 return true;
             }

lfs.h

@@ -44,9 +44,9 @@ enum lfs_error {
 
 // File types
 enum lfs_type {
-    LFS_TYPE_REG        = 0x01,
+    LFS_TYPE_REG        = 0x11,
-    LFS_TYPE_DIR        = 0x02,
+    LFS_TYPE_DIR        = 0x22,
-    LFS_TYPE_SUPERBLOCK = 0x12,
+    LFS_TYPE_SUPERBLOCK = 0xe2,
 };
 
 // File open flags
@@ -159,7 +159,8 @@ typedef struct lfs_entry {
     lfs_off_t off;
 
     struct lfs_disk_entry {
-        uint16_t type;
+        uint8_t type;
+        uint8_t name;
         uint16_t len;
         union {
             struct {
@@ -210,13 +211,14 @@ typedef struct lfs_superblock {
     lfs_off_t off;
 
     struct lfs_disk_superblock {
-        uint16_t type;
+        uint8_t type;
+        uint8_t name;
         uint16_t len;
         lfs_block_t root[2];
-        uint32_t version;
-        char magic[8];
         uint32_t block_size;
         uint32_t block_count;
+        uint32_t version;
+        char magic[8];
     } d;
 } lfs_superblock_t;