Fixed incorrect documentation in test.py

The argparse documented an outdated format, and was off by 1.

Found by sender6

.gitignore

@@ -8,3 +8,5 @@ blocks/
 lfs
 test.c
 tests/*.toml.*
+scripts/__pycache__
+.gdb_history

.travis.yml

@@ -208,6 +208,38 @@ jobs:
     script:
       - make test TFLAGS+="-k --valgrind"
 
+  # test compilation in read-only mode
+  - stage: test
+    env:
+      - NAME=littlefs-readonly
+      - CC="arm-linux-gnueabi-gcc --static -mthumb"
+      - CFLAGS="-Werror -DLFS_READONLY"
+    if: branch !~ -prefix$
+    install:
+      - *install-common
+      - sudo apt-get install
+            gcc-arm-linux-gnueabi
+            libc6-dev-armel-cross
+      - arm-linux-gnueabi-gcc --version
+    # report-size will compile littlefs and report the size
+    script: [*report-size]
+
+  # test compilation in thread-safe mode
+  - stage: test
+    env:
+      - NAME=littlefs-threadsafe
+      - CC="arm-linux-gnueabi-gcc --static -mthumb"
+      - CFLAGS="-Werror -DLFS_THREADSAFE"
+    if: branch !~ -prefix$
+    install:
+      - *install-common
+      - sudo apt-get install
+            gcc-arm-linux-gnueabi
+            libc6-dev-armel-cross
+      - arm-linux-gnueabi-gcc --version
+    # report-size will compile littlefs and report the size
+    script: [*report-size]
+
   # self-host with littlefs-fuse for fuzz test
   - stage: test
     env:

Makefile

@@ -26,8 +26,6 @@ endif
 override CFLAGS += -I.
 override CFLAGS += -std=c99 -Wall -pedantic
 override CFLAGS += -Wextra -Wshadow -Wjump-misses-init -Wundef
-# Remove missing-field-initializers because of GCC bug
-override CFLAGS += -Wno-missing-field-initializers
 
 ifdef VERBOSE
 override TFLAGS += -v

README.md

@@ -115,6 +115,9 @@ the filesystem until sync or close is called on the file.
 
 ## Other notes
 
+Littlefs is written in C, and specifically should compile with any compiler
+that conforms to the `C99` standard.
+
 All littlefs calls have the potential to return a negative error code. The
 errors can be either one of those found in the `enum lfs_error` in
 [lfs.h](lfs.h), or an error returned by the user's block device operations.
@@ -218,6 +221,11 @@ License Identifiers that are here available: http://spdx.org/licenses/
 - [littlefs-js] - A javascript wrapper for littlefs. I'm not sure why you would
   want this, but it is handy for demos.  You can see it in action
   [here][littlefs-js-demo].
+  
+- [littlefs-python] - A Python wrapper for littlefs. The project allows you
+  to create images of the filesystem on your PC. Check if littlefs will fit
+  your needs, create images for a later download to the target memory or
+  inspect the content of a binary image of the target memory.
 
 - [mklfs] - A command line tool built by the [Lua RTOS] guys for making
   littlefs images from a host PC. Supports Windows, Mac OS, and Linux.
@@ -247,3 +255,4 @@ License Identifiers that are here available: http://spdx.org/licenses/
 [LittleFileSystem]: https://os.mbed.com/docs/mbed-os/v5.12/apis/littlefilesystem.html
 [SPIFFS]: https://github.com/pellepl/spiffs
 [Dhara]: https://github.com/dlbeer/dhara
+[littlefs-python]: https://pypi.org/project/littlefs-python/

SPEC.md

@@ -289,8 +289,8 @@ Layout of the name tag:
 ```
         tag                          data
 [--      32      --][---        variable length        ---]
-[1| 3| 8 | 10 | 10 ][---            (size)             ---]
- ^  ^  ^    ^    ^- size               ^- file name
+[1| 3| 8 | 10 | 10 ][---          (size * 8)           ---]
+ ^  ^  ^    ^    ^- size                   ^- file name
  |  |  |    '------ id
  |  |  '----------- file type
  |  '-------------- type1 (0x0)
@@ -470,8 +470,8 @@ Layout of the inline-struct tag:
 ```
         tag                          data
 [--      32      --][---        variable length        ---]
-[1|- 11 -| 10 | 10 ][---            (size)             ---]
- ^    ^     ^    ^- size               ^- inline data
+[1|- 11 -| 10 | 10 ][---           (size * 8)          ---]
+ ^    ^     ^    ^- size                    ^- inline data
  |    |     '------ id
  |    '------------ type (0x201)
  '----------------- valid bit
@@ -556,8 +556,8 @@ Layout of the user-attr tag:
 ```
         tag                          data
 [--      32      --][---        variable length        ---]
-[1| 3| 8 | 10 | 10 ][---            (size)             ---]
- ^  ^  ^    ^    ^- size               ^- attr data
+[1| 3| 8 | 10 | 10 ][---           (size * 8)          ---]
+ ^  ^  ^    ^    ^- size                    ^- attr data
  |  |  |    '------ id
  |  |  '----------- attr type
  |  '-------------- type1 (0x3)
@@ -764,9 +764,9 @@ Layout of the CRC tag:
 ```
         tag                                    data
 [--      32      --][--      32      --|---        variable length        ---]
-[1| 3| 8 | 10 | 10 ][--      32      --|---            (size)             ---]
- ^  ^  ^    ^    ^            ^- crc                      ^- padding
- |  |  |    |    '- size (12)
+[1| 3| 8 | 10 | 10 ][--      32      --|---        (size * 8 - 32)        ---]
+ ^  ^  ^    ^    ^            ^- crc                             ^- padding
+ |  |  |    |    '- size
  |  |  |    '------ id (0x3ff)
  |  |  '----------- valid state
  |  '-------------- type1 (0x5)

bd/lfs_filebd.c

@@ -12,7 +12,7 @@
 
 int lfs_filebd_createcfg(const struct lfs_config *cfg, const char *path,
         const struct lfs_filebd_config *bdcfg) {
-    LFS_TRACE("lfs_filebd_createcfg(%p {.context=%p, "
+    LFS_FILEBD_TRACE("lfs_filebd_createcfg(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -30,16 +30,16 @@ int lfs_filebd_createcfg(const struct lfs_config *cfg, const char *path,
     bd->fd = open(path, O_RDWR | O_CREAT, 0666);
     if (bd->fd < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_createcfg -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_createcfg -> %d", err);
         return err;
     }
 
-    LFS_TRACE("lfs_filebd_createcfg -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_createcfg -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_create(const struct lfs_config *cfg, const char *path) {
-    LFS_TRACE("lfs_filebd_create(%p {.context=%p, "
+    LFS_FILEBD_TRACE("lfs_filebd_create(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -51,26 +51,27 @@ int lfs_filebd_create(const struct lfs_config *cfg, const char *path) {
             path);
     static const struct lfs_filebd_config defaults = {.erase_value=-1};
     int err = lfs_filebd_createcfg(cfg, path, &defaults);
-    LFS_TRACE("lfs_filebd_create -> %d", err);
+    LFS_FILEBD_TRACE("lfs_filebd_create -> %d", err);
     return err;
 }
 
 int lfs_filebd_destroy(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_filebd_destroy(%p)", (void*)cfg);
+    LFS_FILEBD_TRACE("lfs_filebd_destroy(%p)", (void*)cfg);
     lfs_filebd_t *bd = cfg->context;
     int err = close(bd->fd);
     if (err < 0) {
         err = -errno;
-        LFS_TRACE("lfs_filebd_destroy -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_destroy -> %d", err);
         return err;
     }
-    LFS_TRACE("lfs_filebd_destroy -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_destroy -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_filebd_read(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_FILEBD_TRACE("lfs_filebd_read(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_filebd_t *bd = cfg->context;
 
@@ -89,24 +90,24 @@ int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
             (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_read -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_read -> %d", err);
         return err;
     }
 
     ssize_t res2 = read(bd->fd, buffer, size);
     if (res2 < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_read -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_read -> %d", err);
         return err;
     }
 
-    LFS_TRACE("lfs_filebd_read -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_read -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, const void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_filebd_prog(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_FILEBD_TRACE("lfs_filebd_prog(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_filebd_t *bd = cfg->context;
 
@@ -121,7 +122,7 @@ int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
                 (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
         if (res1 < 0) {
             int err = -errno;
-            LFS_TRACE("lfs_filebd_prog -> %d", err);
+            LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
             return err;
         }
 
@@ -130,7 +131,7 @@ int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
             ssize_t res2 = read(bd->fd, &c, 1);
             if (res2 < 0) {
                 int err = -errno;
-                LFS_TRACE("lfs_filebd_prog -> %d", err);
+                LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
                 return err;
             }
 
@@ -143,23 +144,23 @@ int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
             (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_prog -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
         return err;
     }
 
     ssize_t res2 = write(bd->fd, buffer, size);
     if (res2 < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_prog -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
         return err;
     }
 
-    LFS_TRACE("lfs_filebd_prog -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    LFS_TRACE("lfs_filebd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
+    LFS_FILEBD_TRACE("lfs_filebd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
     lfs_filebd_t *bd = cfg->context;
 
     // check if erase is valid
@@ -170,7 +171,7 @@ int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
         off_t res1 = lseek(bd->fd, (off_t)block*cfg->block_size, SEEK_SET);
         if (res1 < 0) {
             int err = -errno;
-            LFS_TRACE("lfs_filebd_erase -> %d", err);
+            LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", err);
             return err;
         }
 
@@ -178,27 +179,27 @@ int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
             ssize_t res2 = write(bd->fd, &(uint8_t){bd->cfg->erase_value}, 1);
             if (res2 < 0) {
                 int err = -errno;
-                LFS_TRACE("lfs_filebd_erase -> %d", err);
+                LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", err);
                 return err;
             }
         }
     }
 
-    LFS_TRACE("lfs_filebd_erase -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_sync(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_filebd_sync(%p)", (void*)cfg);
+    LFS_FILEBD_TRACE("lfs_filebd_sync(%p)", (void*)cfg);
     // file sync
     lfs_filebd_t *bd = cfg->context;
     int err = fsync(bd->fd);
     if (err) {
         err = -errno;
-        LFS_TRACE("lfs_filebd_sync -> %d", 0);
+        LFS_FILEBD_TRACE("lfs_filebd_sync -> %d", 0);
         return err;
     }
 
-    LFS_TRACE("lfs_filebd_sync -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_sync -> %d", 0);
     return 0;
 }

bd/lfs_filebd.h

@@ -15,6 +15,14 @@ extern "C"
 {
 #endif
 
+
+// Block device specific tracing
+#ifdef LFS_FILEBD_YES_TRACE
+#define LFS_FILEBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
+#else
+#define LFS_FILEBD_TRACE(...)
+#endif
+
 // filebd config (optional)
 struct lfs_filebd_config {
     // 8-bit erase value to use for simulating erases. -1 does not simulate

bd/lfs_rambd.c

@@ -8,7 +8,7 @@
 
 int lfs_rambd_createcfg(const struct lfs_config *cfg,
         const struct lfs_rambd_config *bdcfg) {
-    LFS_TRACE("lfs_rambd_createcfg(%p {.context=%p, "
+    LFS_RAMBD_TRACE("lfs_rambd_createcfg(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -27,7 +27,7 @@ int lfs_rambd_createcfg(const struct lfs_config *cfg,
     } else {
         bd->buffer = lfs_malloc(cfg->block_size * cfg->block_count);
         if (!bd->buffer) {
-            LFS_TRACE("lfs_rambd_createcfg -> %d", LFS_ERR_NOMEM);
+            LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", LFS_ERR_NOMEM);
             return LFS_ERR_NOMEM;
         }
     }
@@ -38,12 +38,12 @@ int lfs_rambd_createcfg(const struct lfs_config *cfg,
                 cfg->block_size * cfg->block_count);
     }
 
-    LFS_TRACE("lfs_rambd_createcfg -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_create(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_rambd_create(%p {.context=%p, "
+    LFS_RAMBD_TRACE("lfs_rambd_create(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"})",
@@ -53,24 +53,25 @@ int lfs_rambd_create(const struct lfs_config *cfg) {
             cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count);
     static const struct lfs_rambd_config defaults = {.erase_value=-1};
     int err = lfs_rambd_createcfg(cfg, &defaults);
-    LFS_TRACE("lfs_rambd_create -> %d", err);
+    LFS_RAMBD_TRACE("lfs_rambd_create -> %d", err);
     return err;
 }
 
 int lfs_rambd_destroy(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_rambd_destroy(%p)", (void*)cfg);
+    LFS_RAMBD_TRACE("lfs_rambd_destroy(%p)", (void*)cfg);
     // clean up memory
     lfs_rambd_t *bd = cfg->context;
     if (!bd->cfg->buffer) {
         lfs_free(bd->buffer);
     }
-    LFS_TRACE("lfs_rambd_destroy -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_destroy -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_read(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_rambd_read(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_RAMBD_TRACE("lfs_rambd_read(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_rambd_t *bd = cfg->context;
 
@@ -82,13 +83,14 @@ int lfs_rambd_read(const struct lfs_config *cfg, lfs_block_t block,
     // read data
     memcpy(buffer, &bd->buffer[block*cfg->block_size + off], size);
 
-    LFS_TRACE("lfs_rambd_read -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_read -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_prog(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, const void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_rambd_prog(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_RAMBD_TRACE("lfs_rambd_prog(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_rambd_t *bd = cfg->context;
 
@@ -108,12 +110,12 @@ int lfs_rambd_prog(const struct lfs_config *cfg, lfs_block_t block,
     // program data
     memcpy(&bd->buffer[block*cfg->block_size + off], buffer, size);
 
-    LFS_TRACE("lfs_rambd_prog -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_prog -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    LFS_TRACE("lfs_rambd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
+    LFS_RAMBD_TRACE("lfs_rambd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
     lfs_rambd_t *bd = cfg->context;
 
     // check if erase is valid
@@ -125,14 +127,14 @@ int lfs_rambd_erase(const struct lfs_config *cfg, lfs_block_t block) {
                 bd->cfg->erase_value, cfg->block_size);
     }
 
-    LFS_TRACE("lfs_rambd_erase -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_erase -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_sync(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_rambd_sync(%p)", (void*)cfg);
+    LFS_RAMBD_TRACE("lfs_rambd_sync(%p)", (void*)cfg);
     // sync does nothing because we aren't backed by anything real
     (void)cfg;
-    LFS_TRACE("lfs_rambd_sync -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_sync -> %d", 0);
     return 0;
 }

bd/lfs_rambd.h

@@ -15,6 +15,14 @@ extern "C"
 {
 #endif
 
+
+// Block device specific tracing
+#ifdef LFS_RAMBD_YES_TRACE
+#define LFS_RAMBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
+#else
+#define LFS_RAMBD_TRACE(...)
+#endif
+
 // rambd config (optional)
 struct lfs_rambd_config {
     // 8-bit erase value to simulate erasing with. -1 indicates no erase

bd/lfs_testbd.c

@@ -12,7 +12,7 @@
 
 int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
         const struct lfs_testbd_config *bdcfg) {
-    LFS_TRACE("lfs_testbd_createcfg(%p {.context=%p, "
+    LFS_TESTBD_TRACE("lfs_testbd_createcfg(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -38,9 +38,9 @@ int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
         if (bd->cfg->wear_buffer) {
             bd->wear = bd->cfg->wear_buffer;
         } else {
-            bd->wear = lfs_malloc(sizeof(lfs_testbd_wear_t) * cfg->block_count);
+            bd->wear = lfs_malloc(sizeof(lfs_testbd_wear_t)*cfg->block_count);
             if (!bd->wear) {
-                LFS_TRACE("lfs_testbd_createcfg -> %d", LFS_ERR_NOMEM);
+                LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", LFS_ERR_NOMEM);
                 return LFS_ERR_NOMEM;
             }
         }
@@ -54,7 +54,7 @@ int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
             .erase_value = bd->cfg->erase_value,
         };
         int err = lfs_filebd_createcfg(cfg, path, &bd->u.file.cfg);
-        LFS_TRACE("lfs_testbd_createcfg -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", err);
         return err;
     } else {
         bd->u.ram.cfg = (struct lfs_rambd_config){
@@ -62,13 +62,13 @@ int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
             .buffer = bd->cfg->buffer,
         };
         int err = lfs_rambd_createcfg(cfg, &bd->u.ram.cfg);
-        LFS_TRACE("lfs_testbd_createcfg -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", err);
         return err;
     }
 }
 
 int lfs_testbd_create(const struct lfs_config *cfg, const char *path) {
-    LFS_TRACE("lfs_testbd_create(%p {.context=%p, "
+    LFS_TESTBD_TRACE("lfs_testbd_create(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -80,12 +80,12 @@ int lfs_testbd_create(const struct lfs_config *cfg, const char *path) {
             path);
     static const struct lfs_testbd_config defaults = {.erase_value=-1};
     int err = lfs_testbd_createcfg(cfg, path, &defaults);
-    LFS_TRACE("lfs_testbd_create -> %d", err);
+    LFS_TESTBD_TRACE("lfs_testbd_create -> %d", err);
     return err;
 }
 
 int lfs_testbd_destroy(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_testbd_destroy(%p)", (void*)cfg);
+    LFS_TESTBD_TRACE("lfs_testbd_destroy(%p)", (void*)cfg);
     lfs_testbd_t *bd = cfg->context;
     if (bd->cfg->erase_cycles && !bd->cfg->wear_buffer) {
         lfs_free(bd->wear);
@@ -93,11 +93,11 @@ int lfs_testbd_destroy(const struct lfs_config *cfg) {
 
     if (bd->persist) {
         int err = lfs_filebd_destroy(cfg);
-        LFS_TRACE("lfs_testbd_destroy -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_destroy -> %d", err);
         return err;
     } else {
         int err = lfs_rambd_destroy(cfg);
-        LFS_TRACE("lfs_testbd_destroy -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_destroy -> %d", err);
         return err;
     }
 }
@@ -145,7 +145,8 @@ static int lfs_testbd_rawsync(const struct lfs_config *cfg) {
 /// block device API ///
 int lfs_testbd_read(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_testbd_read(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_TESTBD_TRACE("lfs_testbd_read(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_testbd_t *bd = cfg->context;
 
@@ -157,19 +158,20 @@ int lfs_testbd_read(const struct lfs_config *cfg, lfs_block_t block,
     // block bad?
     if (bd->cfg->erase_cycles && bd->wear[block] >= bd->cfg->erase_cycles &&
             bd->cfg->badblock_behavior == LFS_TESTBD_BADBLOCK_READERROR) {
-        LFS_TRACE("lfs_testbd_read -> %d", LFS_ERR_CORRUPT);
+        LFS_TESTBD_TRACE("lfs_testbd_read -> %d", LFS_ERR_CORRUPT);
         return LFS_ERR_CORRUPT;
     }
 
     // read
     int err = lfs_testbd_rawread(cfg, block, off, buffer, size);
-    LFS_TRACE("lfs_testbd_read -> %d", err);
+    LFS_TESTBD_TRACE("lfs_testbd_read -> %d", err);
     return err;
 }
 
 int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, const void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_testbd_prog(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_TESTBD_TRACE("lfs_testbd_prog(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_testbd_t *bd = cfg->context;
 
@@ -182,13 +184,13 @@ int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
     if (bd->cfg->erase_cycles && bd->wear[block] >= bd->cfg->erase_cycles) {
         if (bd->cfg->badblock_behavior ==
                 LFS_TESTBD_BADBLOCK_PROGERROR) {
-            LFS_TRACE("lfs_testbd_prog -> %d", LFS_ERR_CORRUPT);
+            LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", LFS_ERR_CORRUPT);
             return LFS_ERR_CORRUPT;
         } else if (bd->cfg->badblock_behavior ==
                 LFS_TESTBD_BADBLOCK_PROGNOOP ||
                 bd->cfg->badblock_behavior ==
                 LFS_TESTBD_BADBLOCK_ERASENOOP) {
-            LFS_TRACE("lfs_testbd_prog -> %d", 0);
+            LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
             return 0;
         }
     }
@@ -196,7 +198,7 @@ int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
     // prog
     int err = lfs_testbd_rawprog(cfg, block, off, buffer, size);
     if (err) {
-        LFS_TRACE("lfs_testbd_prog -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", err);
         return err;
     }
 
@@ -205,18 +207,18 @@ int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
         bd->power_cycles -= 1;
         if (bd->power_cycles == 0) {
             // sync to make sure we persist the last changes
-            assert(lfs_testbd_rawsync(cfg) == 0);
+            LFS_ASSERT(lfs_testbd_rawsync(cfg) == 0);
             // simulate power loss
             exit(33);
         }
     }
 
-    LFS_TRACE("lfs_testbd_prog -> %d", 0);
+    LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
     return 0;
 }
 
 int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    LFS_TRACE("lfs_testbd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
+    LFS_TESTBD_TRACE("lfs_testbd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
     lfs_testbd_t *bd = cfg->context;
 
     // check if erase is valid
@@ -227,11 +229,11 @@ int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block) {
         if (bd->wear[block] >= bd->cfg->erase_cycles) {
             if (bd->cfg->badblock_behavior ==
                     LFS_TESTBD_BADBLOCK_ERASEERROR) {
-                LFS_TRACE("lfs_testbd_erase -> %d", LFS_ERR_CORRUPT);
+                LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", LFS_ERR_CORRUPT);
                 return LFS_ERR_CORRUPT;
             } else if (bd->cfg->badblock_behavior ==
                     LFS_TESTBD_BADBLOCK_ERASENOOP) {
-                LFS_TRACE("lfs_testbd_erase -> %d", 0);
+                LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", 0);
                 return 0;
             }
         } else {
@@ -243,7 +245,7 @@ int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block) {
     // erase
     int err = lfs_testbd_rawerase(cfg, block);
     if (err) {
-        LFS_TRACE("lfs_testbd_erase -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", err);
         return err;
     }
 
@@ -252,20 +254,20 @@ int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block) {
         bd->power_cycles -= 1;
         if (bd->power_cycles == 0) {
             // sync to make sure we persist the last changes
-            assert(lfs_testbd_rawsync(cfg) == 0);
+            LFS_ASSERT(lfs_testbd_rawsync(cfg) == 0);
             // simulate power loss
             exit(33);
         }
     }
 
-    LFS_TRACE("lfs_testbd_prog -> %d", 0);
+    LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
     return 0;
 }
 
 int lfs_testbd_sync(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_testbd_sync(%p)", (void*)cfg);
+    LFS_TESTBD_TRACE("lfs_testbd_sync(%p)", (void*)cfg);
     int err = lfs_testbd_rawsync(cfg);
-    LFS_TRACE("lfs_testbd_sync -> %d", err);
+    LFS_TESTBD_TRACE("lfs_testbd_sync -> %d", err);
     return err;
 }
 
@@ -273,20 +275,20 @@ int lfs_testbd_sync(const struct lfs_config *cfg) {
 /// simulated wear operations ///
 lfs_testbd_swear_t lfs_testbd_getwear(const struct lfs_config *cfg,
         lfs_block_t block) {
-    LFS_TRACE("lfs_testbd_getwear(%p, %"PRIu32")", (void*)cfg, block);
+    LFS_TESTBD_TRACE("lfs_testbd_getwear(%p, %"PRIu32")", (void*)cfg, block);
     lfs_testbd_t *bd = cfg->context;
 
     // check if block is valid
     LFS_ASSERT(bd->cfg->erase_cycles);
     LFS_ASSERT(block < cfg->block_count);
 
-    LFS_TRACE("lfs_testbd_getwear -> %"PRIu32, bd->wear[block]);
+    LFS_TESTBD_TRACE("lfs_testbd_getwear -> %"PRIu32, bd->wear[block]);
     return bd->wear[block];
 }
 
 int lfs_testbd_setwear(const struct lfs_config *cfg,
         lfs_block_t block, lfs_testbd_wear_t wear) {
-    LFS_TRACE("lfs_testbd_setwear(%p, %"PRIu32")", (void*)cfg, block);
+    LFS_TESTBD_TRACE("lfs_testbd_setwear(%p, %"PRIu32")", (void*)cfg, block);
     lfs_testbd_t *bd = cfg->context;
 
     // check if block is valid
@@ -295,6 +297,6 @@ int lfs_testbd_setwear(const struct lfs_config *cfg,
 
     bd->wear[block] = wear;
 
-    LFS_TRACE("lfs_testbd_setwear -> %d", 0);
+    LFS_TESTBD_TRACE("lfs_testbd_setwear -> %d", 0);
     return 0;
 }

bd/lfs_testbd.h

@@ -19,6 +19,13 @@ extern "C"
 #endif
 
 
+// Block device specific tracing
+#ifdef LFS_TESTBD_YES_TRACE
+#define LFS_TESTBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
+#else
+#define LFS_TESTBD_TRACE(...)
+#endif
+
 // Mode determining how "bad blocks" behave during testing. This simulates
 // some real-world circumstances such as progs not sticking (prog-noop),
 // a readonly disk (erase-noop), and ECC failures (read-error).

lfs.h

@@ -9,6 +9,7 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+#include "lfs_util.h"
 
 #ifdef __cplusplus
 extern "C"
@@ -21,7 +22,7 @@ extern "C"
 // Software library version
 // Major (top-nibble), incremented on backwards incompatible changes
 // Minor (bottom-nibble), incremented on feature additions
-#define LFS_VERSION 0x00020001
+#define LFS_VERSION 0x00020003
 #define LFS_VERSION_MAJOR (0xffff & (LFS_VERSION >> 16))
 #define LFS_VERSION_MINOR (0xffff & (LFS_VERSION >>  0))
 
@@ -111,34 +112,37 @@ enum lfs_type {
     LFS_TYPE_INLINESTRUCT   = 0x201,
     LFS_TYPE_SOFTTAIL       = 0x600,
     LFS_TYPE_HARDTAIL       = 0x601,
-    LFS_TYPE_BRANCH         = 0x681,
     LFS_TYPE_MOVESTATE      = 0x7ff,
 
     // internal chip sources
     LFS_FROM_NOOP           = 0x000,
     LFS_FROM_MOVE           = 0x101,
-    LFS_FROM_DROP           = 0x102,
-    LFS_FROM_USERATTRS      = 0x103,
+    LFS_FROM_USERATTRS      = 0x102,
 };
 
 // File open flags
 enum lfs_open_flags {
     // open flags
     LFS_O_RDONLY = 1,         // Open a file as read only
+#ifndef LFS_READONLY
     LFS_O_WRONLY = 2,         // Open a file as write only
     LFS_O_RDWR   = 3,         // Open a file as read and write
     LFS_O_CREAT  = 0x0100,    // Create a file if it does not exist
     LFS_O_EXCL   = 0x0200,    // Fail if a file already exists
     LFS_O_TRUNC  = 0x0400,    // Truncate the existing file to zero size
     LFS_O_APPEND = 0x0800,    // Move to end of file on every write
+#endif
 
     // internally used flags
+#ifndef LFS_READONLY
     LFS_F_DIRTY   = 0x010000, // File does not match storage
     LFS_F_WRITING = 0x020000, // File has been written since last flush
+#endif
     LFS_F_READING = 0x040000, // File has been read since last flush
-    LFS_F_ERRED   = 0x080000, // An error occured during write
+#ifndef LFS_READONLY
+    LFS_F_ERRED   = 0x080000, // An error occurred during write
+#endif
     LFS_F_INLINE  = 0x100000, // Currently inlined in directory entry
-    LFS_F_OPENED  = 0x200000, // File has been opened
 };
 
 // File seek flags
@@ -176,6 +180,16 @@ struct lfs_config {
     // are propogated to the user.
     int (*sync)(const struct lfs_config *c);
 
+#ifdef LFS_THREADSAFE
+    // Lock the underlying block device. Negative error codes
+    // are propogated to the user.
+    int (*lock)(const struct lfs_config *c);
+
+    // Unlock the underlying block device. Negative error codes
+    // are propogated to the user.
+    int (*unlock)(const struct lfs_config *c);
+#endif
+
     // Minimum size of a block read. All read operations will be a
     // multiple of this value.
     lfs_size_t read_size;
@@ -312,11 +326,8 @@ typedef struct lfs_mdir {
     uint32_t etag;
     uint16_t count;
     bool erased;
-    bool first; // TODO come on
     bool split;
-    bool mustrelocate; // TODO not great either
     lfs_block_t tail[2];
-    lfs_block_t branch[2];
 } lfs_mdir_t;
 
 // littlefs directory type
@@ -371,9 +382,6 @@ typedef struct lfs {
     lfs_cache_t pcache;
 
     lfs_block_t root[2];
-    lfs_block_t relocate_tail[2];
-    lfs_block_t relocate_end[2];
-    bool relocate_do_hack; // TODO fixme
     struct lfs_mlist {
         struct lfs_mlist *next;
         uint16_t id;
@@ -407,6 +415,7 @@ typedef struct lfs {
 
 /// Filesystem functions ///
 
+#ifndef LFS_READONLY
 // Format a block device with the littlefs
 //
 // Requires a littlefs object and config struct. This clobbers the littlefs
@@ -415,6 +424,7 @@ typedef struct lfs {
 //
 // Returns a negative error code on failure.
 int lfs_format(lfs_t *lfs, const struct lfs_config *config);
+#endif
 
 // Mounts a littlefs
 //
@@ -434,12 +444,15 @@ int lfs_unmount(lfs_t *lfs);
 
 /// General operations ///
 
+#ifndef LFS_READONLY
 // Removes a file or directory
 //
 // If removing a directory, the directory must be empty.
 // Returns a negative error code on failure.
 int lfs_remove(lfs_t *lfs, const char *path);
+#endif
 
+#ifndef LFS_READONLY
 // Rename or move a file or directory
 //
 // If the destination exists, it must match the source in type.
@@ -447,6 +460,7 @@ int lfs_remove(lfs_t *lfs, const char *path);
 //
 // Returns a negative error code on failure.
 int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath);
+#endif
 
 // Find info about a file or directory
 //
@@ -469,6 +483,7 @@ int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
 lfs_ssize_t lfs_getattr(lfs_t *lfs, const char *path,
         uint8_t type, void *buffer, lfs_size_t size);
 
+#ifndef LFS_READONLY
 // Set custom attributes
 //
 // Custom attributes are uniquely identified by an 8-bit type and limited
@@ -478,13 +493,16 @@ lfs_ssize_t lfs_getattr(lfs_t *lfs, const char *path,
 // Returns a negative error code on failure.
 int lfs_setattr(lfs_t *lfs, const char *path,
         uint8_t type, const void *buffer, lfs_size_t size);
+#endif
 
+#ifndef LFS_READONLY
 // Removes a custom attribute
 //
 // If an attribute is not found, nothing happens.
 //
 // Returns a negative error code on failure.
 int lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type);
+#endif
 
 
 /// File operations ///
@@ -533,6 +551,7 @@ int lfs_file_sync(lfs_t *lfs, lfs_file_t *file);
 lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
         void *buffer, lfs_size_t size);
 
+#ifndef LFS_READONLY
 // Write data to file
 //
 // Takes a buffer and size indicating the data to write. The file will not
@@ -541,6 +560,7 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
 // Returns the number of bytes written, or a negative error code on failure.
 lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
         const void *buffer, lfs_size_t size);
+#endif
 
 // Change the position of the file
 //
@@ -549,10 +569,12 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
 lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
         lfs_soff_t off, int whence);
 
+#ifndef LFS_READONLY
 // Truncates the size of the file to the specified size
 //
 // Returns a negative error code on failure.
 int lfs_file_truncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size);
+#endif
 
 // Return the position of the file
 //
@@ -575,10 +597,12 @@ lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file);
 
 /// Directory operations ///
 
+#ifndef LFS_READONLY
 // Create a directory
 //
 // Returns a negative error code on failure.
 int lfs_mkdir(lfs_t *lfs, const char *path);
+#endif
 
 // Open a directory
 //
@@ -640,6 +664,7 @@ lfs_ssize_t lfs_fs_size(lfs_t *lfs);
 // Returns a negative error code on failure.
 int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
 
+#ifndef LFS_READONLY
 #ifdef LFS_MIGRATE
 // Attempts to migrate a previous version of littlefs
 //
@@ -654,6 +679,7 @@ int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
 // Returns a negative error code on failure.
 int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg);
 #endif
+#endif
 
 
 #ifdef __cplusplus

lfs_util.h

@@ -50,31 +50,35 @@ extern "C"
 
 // Logging functions
 #ifdef LFS_YES_TRACE
-#define LFS_TRACE(fmt, ...) \
-    printf("%s:%d:trace: " fmt "\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_TRACE_(fmt, ...) \
+    printf("%s:%d:trace: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_TRACE(...) LFS_TRACE_(__VA_ARGS__, "")
 #else
-#define LFS_TRACE(fmt, ...)
+#define LFS_TRACE(...)
 #endif
 
 #ifndef LFS_NO_DEBUG
-#define LFS_DEBUG(fmt, ...) \
-    printf("%s:%d:debug: " fmt "\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_DEBUG_(fmt, ...) \
+    printf("%s:%d:debug: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_DEBUG(...) LFS_DEBUG_(__VA_ARGS__, "")
 #else
-#define LFS_DEBUG(fmt, ...)
+#define LFS_DEBUG(...)
 #endif
 
 #ifndef LFS_NO_WARN
-#define LFS_WARN(fmt, ...) \
-    printf("%s:%d:warn: " fmt "\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_WARN_(fmt, ...) \
+    printf("%s:%d:warn: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_WARN(...) LFS_WARN_(__VA_ARGS__, "")
 #else
-#define LFS_WARN(fmt, ...)
+#define LFS_WARN(...)
 #endif
 
 #ifndef LFS_NO_ERROR
-#define LFS_ERROR(fmt, ...) \
-    printf("%s:%d:error: " fmt "\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_ERROR_(fmt, ...) \
+    printf("%s:%d:error: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_ERROR(...) LFS_ERROR_(__VA_ARGS__, "")
 #else
-#define LFS_ERROR(fmt, ...)
+#define LFS_ERROR(...)
 #endif
 
 // Runtime assertions
@@ -107,7 +111,7 @@ 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
+// Find the smallest power of 2 greater than or equal to a
 static inline uint32_t lfs_npw2(uint32_t a) {
 #if !defined(LFS_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM))
     return 32 - __builtin_clz(a-1);

scripts/readmdir.py

@@ -18,10 +18,9 @@ TAG_TYPES = {
     'ctzstruct':    (0x7ff, 0x202),
     'inlinestruct': (0x7ff, 0x201),
     'userattr':     (0x700, 0x300),
-    'tail':         (0x700, 0x600), # TODO rename these?
+    'tail':         (0x700, 0x600),
     'softtail':     (0x7ff, 0x600),
     'hardtail':     (0x7ff, 0x601),
-    'branch':       (0x7ff, 0x681),
     'gstate':       (0x700, 0x700),
     'movestate':    (0x7ff, 0x7ff),
     'crc':          (0x700, 0x500),
@@ -104,7 +103,7 @@ class Tag:
 
     def mkmask(self):
         return Tag(
-            0x780 if self.is_('tail') else 0x700 if self.isunique else 0x7ff, # TODO best way?
+            0x700 if self.isunique else 0x7ff,
             0x3ff if self.isattr else 0,
             0)
 
@@ -319,14 +318,24 @@ def main(args):
 
     # find most recent pair
     mdir = MetadataPair(blocks)
-    print("mdir {%s} rev %d%s%s" % (
+
+    try:
+        mdir.tail = mdir[Tag('tail', 0, 0)]
+        if mdir.tail.size != 8 or mdir.tail.data == 8*b'\xff':
+            mdir.tail = None
+    except KeyError:
+        mdir.tail = None
+
+    print("mdir {%s} rev %d%s%s%s" % (
         ', '.join('%#x' % b
             for b in [args.block1, args.block2]
             if b is not None),
         mdir.rev,
         ' (was %s)' % ', '.join('%d' % m.rev for m in mdir.pair[1:])
         if len(mdir.pair) > 1 else '',
-        ' (corrupted!)' if not mdir else ''))
+        ' (corrupted!)' if not mdir else '',
+        ' -> {%#x, %#x}' % struct.unpack('<II', mdir.tail.data)
+        if mdir.tail else ''))
     if args.all:
         mdir.dump_all(truncate=not args.no_truncate)
     elif args.log:

scripts/readtree.py

@@ -5,107 +5,24 @@ import sys
 import json
 import io
 import itertools as it
-import collections as c
 from readmdir import Tag, MetadataPair
 
-def popc(x):
-    return bin(x).count('1')
-
-def ctz(x):
-    return len(bin(x)) - len(bin(x).rstrip('0'))
-
-def dumpentries(args, mdir, mdirs, f):
-    for k, id_ in enumerate(mdir.ids):
-        name = mdir[Tag('name', id_, 0)]
-        struct_ = mdir[Tag('struct', id_, 0)]
-
-        desc = "id %d %s %s" % (
-            id_, name.typerepr(),
-            json.dumps(name.data.decode('utf8')))
-        if struct_.is_('dirstruct'):
-            pair = struct.unpack('<II', struct_.data[:8].ljust(8, b'\xff'))
-            desc += " dir {%#x, %#x}%s" % (
-                pair[0], pair[1],
-                '?' if frozenset(pair) not in mdirs else '')
-        if struct_.is_('ctzstruct'):
-            desc += " ctz {%#x} size %d" % struct.unpack(
-                '<II', struct_.data[:8].ljust(8, b'\xff'))
-        if struct_.is_('inlinestruct'):
-            desc += " inline size %d" % struct_.size
-
-        data = None
-        if struct_.is_('inlinestruct'):
-            data = struct_.data
-        elif struct_.is_('ctzstruct'):
-            block, size = struct.unpack(
-                '<II', struct_.data[:8].ljust(8, b'\xff'))
-            data = []
-            i = 0 if size == 0 else (size-1) // (args.block_size - 8)
-            if i != 0:
-                i = ((size-1) - 4*popc(i-1)+2) // (args.block_size - 8)
-            with open(args.disk, 'rb') as f2:
-                while i >= 0:
-                    f2.seek(block * args.block_size)
-                    dat = f2.read(args.block_size)
-                    data.append(dat[4*(ctz(i)+1) if i != 0 else 0:])
-                    block, = struct.unpack('<I', dat[:4].ljust(4, b'\xff'))
-                    i -= 1
-            data = bytes(it.islice(
-                it.chain.from_iterable(reversed(data)), size))
-
-        f.write("%-45s%s\n" % (desc,
-            "%-23s  %-8s" % (
-                ' '.join('%02x' % c for c in data[:8]),
-                ''.join(c if c >= ' ' and c <= '~' else '.'
-                    for c in map(chr, data[:8])))
-            if not args.no_truncate and len(desc) < 45
-                and data is not None else ""))
-
-        if name.is_('superblock') and struct_.is_('inlinestruct'):
-            f.write(
-                "  block_size %d\n"
-                "  block_count %d\n"
-                "  name_max %d\n"
-                "  file_max %d\n"
-                "  attr_max %d\n" % struct.unpack(
-                    '<IIIII', struct_.data[4:4+20].ljust(20, b'\xff')))
-
-        for tag in mdir.tags:
-            if tag.id==id_ and tag.is_('userattr'):
-                desc = "%s size %d" % (tag.typerepr(), tag.size)
-                f.write("  %-43s%s\n" % (desc,
-                    "%-23s  %-8s" % (
-                        ' '.join('%02x' % c for c in tag.data[:8]),
-                        ''.join(c if c >= ' ' and c <= '~' else '.'
-                            for c in map(chr, tag.data[:8])))
-                    if not args.no_truncate and len(desc) < 43 else ""))
-
-                if args.no_truncate:
-                    for i in range(0, len(tag.data), 16):
-                        f.write("    %08x: %-47s  %-16s\n" % (
-                            i, ' '.join('%02x' % c for c in tag.data[i:i+16]),
-                            ''.join(c if c >= ' ' and c <= '~' else '.'
-                                for c in map(chr, tag.data[i:i+16]))))
-
-        if args.no_truncate and data is not None:
-            for i in range(0, len(data), 16):
-                f.write("  %08x: %-47s  %-16s\n" % (
-                    i, ' '.join('%02x' % c for c in data[i:i+16]),
-                    ''.join(c if c >= ' ' and c <= '~' else '.'
-                        for c in map(chr, data[i:i+16]))))
-
 def main(args):
     superblock = None
     gstate = b'\0\0\0\0\0\0\0\0\0\0\0\0'
-    mdirs = c.OrderedDict()
+    dirs = []
+    mdirs = []
     corrupted = []
     cycle = False
     with open(args.disk, 'rb') as f:
         tail = (args.block1, args.block2)
-        while tail:
-            if frozenset(tail) in mdirs:
-                # cycle detected
-                cycle = tail
+        hard = False
+        while True:
+            for m in it.chain((m for d in dirs for m in d), mdirs):
+                if set(m.blocks) == set(tail):
+                    # cycle detected
+                    cycle = m.blocks
+            if cycle:
                 break
 
             # load mdir
@@ -128,13 +45,6 @@ def main(args):
             except KeyError:
                 mdir.tail = None
 
-            try:
-                mdir.branch = mdir[Tag('branch', 0, 0)]
-                if mdir.branch.size != 8 or mdir.branch.data == 8*b'\xff':
-                    mdir.branch = None
-            except KeyError:
-                mdir.branch = None
-
             # have superblock?
             try:
                 nsuperblock = mdir[
@@ -155,53 +65,39 @@ def main(args):
             if not mdir:
                 corrupted.append(mdir)
 
-            # add to metadata-pairs
-            mdirs[frozenset(mdir.blocks)] = mdir
-            tail = (struct.unpack('<II', mdir.tail.data)
-                if mdir.tail else None)
+            # add to directories
+            mdirs.append(mdir)
+            if mdir.tail is None or not mdir.tail.is_('hardtail'):
+                dirs.append(mdirs)
+                mdirs = []
 
-    # derive paths and build directories
-    dirs = {}
-    rogue = {}
-    pending = [('/', (args.block1, args.block2))]
+            if mdir.tail is None:
+                break
+
+            tail = struct.unpack('<II', mdir.tail.data)
+            hard = mdir.tail.is_('hardtail')
+
+    # find paths
+    dirtable = {}
+    for dir in dirs:
+        dirtable[frozenset(dir[0].blocks)] = dir
+
+    pending = [("/", dirs[0])]
     while pending:
-        path, branch = pending.pop(0)
-        dir = []
-        while branch and frozenset(branch) in mdirs:
-            mdir = mdirs[frozenset(branch)]
-            dir.append(mdir)
-
+        path, dir = pending.pop(0)
+        for mdir in dir:
             for tag in mdir.tags:
                 if tag.is_('dir'):
                     try:
-                        npath = path + '/' + tag.data.decode('utf8')
-                        npath = npath.replace('//', '/')
+                        npath = tag.data.decode('utf8')
                         dirstruct = mdir[Tag('dirstruct', tag.id, 0)]
-                        npair = struct.unpack('<II', dirstruct.data)
-                        pending.append((npath, npair))
+                        nblocks = struct.unpack('<II', dirstruct.data)
+                        nmdir = dirtable[frozenset(nblocks)]
+                        pending.append(((path + '/' + npath), nmdir))
                     except KeyError:
                         pass
 
-            branch = (struct.unpack('<II', mdir.branch.data)
-                if mdir.branch else None)
-
-        if not dir:
-            rogue[path] = branch
-        else:
-            dirs[path] = dir
-
-    # also find orphans
-    not_orphans = {frozenset(mdir.blocks)
-        for dir in dirs.values()
-        for mdir in dir}
-    orphans = []
-    for pair, mdir in mdirs.items():
-        if pair not in not_orphans:
-            if len(orphans) > 0 and (pair == frozenset(
-                    struct.unpack('<II', orphans[-1][-1].tail.data))):
-                orphans[-1].append(mdir)
-            else:
-                orphans.append([mdir])
+        dir[0].path = path.replace('//', '/')
 
     # print littlefs + version info
     version = ('?', '?')
@@ -210,28 +106,22 @@ def main(args):
             struct.unpack('<HH', superblock[1].data[0:4].ljust(4, b'\xff'))))
     print("%-47s%s" % ("littlefs v%s.%s" % version,
         "data (truncated, if it fits)"
-        if not any([args.no_truncate, args.tags, args.log, args.all]) else ""))
+        if not any([args.no_truncate, args.log, args.all]) else ""))
 
     # print gstate
-    badgstate = None
     print("gstate 0x%s" % ''.join('%02x' % c for c in gstate))
     tag = Tag(struct.unpack('<I', gstate[0:4].ljust(4, b'\xff'))[0])
     blocks = struct.unpack('<II', gstate[4:4+8].ljust(8, b'\xff'))
     if tag.size or not tag.isvalid:
         print("  orphans >=%d" % max(tag.size, 1))
     if tag.type:
-        if frozenset(blocks) not in mdirs:
-            badgstate = gstate
-        print("  move dir {%#x, %#x}%s id %d" % (
-            blocks[0], blocks[1],
-            '?' if frozenset(blocks) not in mdirs else '',
-            tag.id))
+        print("  move dir {%#x, %#x} id %d" % (
+            blocks[0], blocks[1], tag.id))
 
-    # print dir info
-    for path, dir in it.chain(
-            sorted(dirs.items()),
-            zip(it.repeat(None), orphans)):
-        print("dir %s" % json.dumps(path) if path else "orphaned")
+    # print mdir info
+    for i, dir in enumerate(dirs):
+        print("dir %s" % (json.dumps(dir[0].path)
+            if hasattr(dir[0], 'path') else '(orphan)'))
 
         for j, mdir in enumerate(dir):
             print("mdir {%#x, %#x} rev %d (was %d)%s%s" % (
@@ -241,21 +131,19 @@ def main(args):
                 if mdir.tail else ''))
 
             f = io.StringIO()
-            if args.tags:
-                mdir.dump_tags(f, truncate=not args.no_truncate)
-            elif args.log:
+            if args.log:
                 mdir.dump_log(f, truncate=not args.no_truncate)
             elif args.all:
                 mdir.dump_all(f, truncate=not args.no_truncate)
             else:
-                dumpentries(args, mdir, mdirs, f)
+                mdir.dump_tags(f, truncate=not args.no_truncate)
 
             lines = list(filter(None, f.getvalue().split('\n')))
             for k, line in enumerate(lines):
                 print("%s %s" % (
                     ' ' if j == len(dir)-1 else
                     'v' if k == len(lines)-1 else
-                    '|' if path else '.',
+                    '|',
                     line))
 
     errcode = 0
@@ -264,18 +152,8 @@ def main(args):
         print("*** corrupted mdir {%#x, %#x}! ***" % (
             mdir.blocks[0], mdir.blocks[1]))
 
-    for path, pair in rogue.items():
-        errcode = errcode or 2
-        print("*** couldn't find dir %s {%#x, %#x}! ***" % (
-            json.dumps(path), pair[0], pair[1]))
-
-    if badgstate:
-        errcode = errcode or 3
-        print("*** bad gstate 0x%s! ***" %
-            ''.join('%02x' % c for c in gstate))
-
     if cycle:
-        errcode = errcode or 4
+        errcode = errcode or 2
         print("*** cycle detected {%#x, %#x}! ***" % (
             cycle[0], cycle[1]))
 
@@ -292,12 +170,10 @@ if __name__ == "__main__":
         help="Size of a block in bytes.")
     parser.add_argument('block1', nargs='?', default=0,
         type=lambda x: int(x, 0),
-        help="Optional first block address for finding the root.")
+        help="Optional first block address for finding the superblock.")
     parser.add_argument('block2', nargs='?', default=1,
         type=lambda x: int(x, 0),
-        help="Optional second block address for finding the root.")
-    parser.add_argument('-t', '--tags', action='store_true',
-        help="Show metadata tags instead of reconstructing entries.")
+        help="Optional second block address for finding the superblock.")
     parser.add_argument('-l', '--log', action='store_true',
         help="Show tags in log.")
     parser.add_argument('-a', '--all', action='store_true',

scripts/test.py

@@ -231,7 +231,7 @@ class TestCase:
                 ncmd.extend(['-ex', 'r'])
                 if failure.assert_:
                     ncmd.extend(['-ex', 'up 2'])
-            elif gdb == 'start' or isinstance(gdb, int):
+            elif gdb == 'main':
                 ncmd.extend([
                     '-ex', 'b %s:%d' % (self.suite.path, self.code_lineno),
                     '-ex', 'r'])
@@ -329,9 +329,7 @@ class ReentrantTestCase(TestCase):
                 persist = 'noerase'
 
             # exact cycle we should drop into debugger?
-            if gdb and failure and (
-                    failure.cycleno == cycles or
-                    (isinstance(gdb, int) and gdb == cycles)):
+            if gdb and failure and failure.cycleno == cycles:
                 return super().test(gdb=gdb, persist=persist, cycles=cycles,
                     failure=failure, **args)
 
@@ -748,9 +746,9 @@ if __name__ == "__main__":
     parser.add_argument('testpaths', nargs='*', default=[TESTDIR],
         help="Description of test(s) to run. By default, this is all tests \
             found in the \"{0}\" directory. Here, you can specify a different \
-            directory of tests, a specific file, a suite by name, and even a \
-            specific test case by adding brackets. For example \
-            \"test_dirs[0]\" or \"{0}/test_dirs.toml[0]\".".format(TESTDIR))
+            directory of tests, a specific file, a suite by name, and even \
+            specific test cases and permutations. For example \
+            \"test_dirs#1\" or \"{0}/test_dirs.toml#1#1\".".format(TESTDIR))
     parser.add_argument('-D', action='append', default=[],
         help="Overriding parameter definitions.")
     parser.add_argument('-v', '--verbose', action='store_true',
@@ -762,8 +760,7 @@ if __name__ == "__main__":
         help="Store disk image in a file.")
     parser.add_argument('-b', '--build', action='store_true',
         help="Only build the tests, do not execute.")
-    parser.add_argument('-g', '--gdb', metavar='{init,start,assert},CYCLE',
-        type=lambda n: n if n in {'init', 'start', 'assert'} else int(n, 0),
+    parser.add_argument('-g', '--gdb', choices=['init', 'main', 'assert'],
         nargs='?', const='assert',
         help="Drop into gdb on test failure.")
     parser.add_argument('--no-internal', action='store_true',

tests/test_alloc.toml

@@ -323,6 +323,90 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
+[[case]] # what if we have a bad block during an allocation scan?
+in = "lfs.c"
+define.LFS_ERASE_CYCLES = 0xffffffff
+define.LFS_BADBLOCK_BEHAVIOR = 'LFS_TESTBD_BADBLOCK_READERROR'
+code = '''
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    // first fill to exhaustion to find available space
+    lfs_file_open(&lfs, &file, "pacman", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    strcpy((char*)buffer, "waka");
+    size = strlen("waka");
+    lfs_size_t filesize = 0;
+    while (true) {
+        lfs_ssize_t res = lfs_file_write(&lfs, &file, buffer, size);
+        assert(res == (lfs_ssize_t)size || res == LFS_ERR_NOSPC);
+        if (res == LFS_ERR_NOSPC) {
+            break;
+        }
+        filesize += size;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    // now fill all but a couple of blocks of the filesystem with data
+    filesize -= 3*LFS_BLOCK_SIZE;
+    lfs_file_open(&lfs, &file, "pacman", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    strcpy((char*)buffer, "waka");
+    size = strlen("waka");
+    for (lfs_size_t i = 0; i < filesize/size; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    // also save head of file so we can error during lookahead scan
+    lfs_block_t fileblock = file.ctz.head;
+    lfs_unmount(&lfs) => 0;
+
+    // remount to force an alloc scan
+    lfs_mount(&lfs, &cfg) => 0;
+
+    // but mark the head of our file as a "bad block", this is force our
+    // scan to bail early
+    lfs_testbd_setwear(&cfg, fileblock, 0xffffffff) => 0;
+    lfs_file_open(&lfs, &file, "ghost", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    strcpy((char*)buffer, "chomp");
+    size = strlen("chomp");
+    while (true) {
+        lfs_ssize_t res = lfs_file_write(&lfs, &file, buffer, size);
+        assert(res == (lfs_ssize_t)size || res == LFS_ERR_CORRUPT);
+        if (res == LFS_ERR_CORRUPT) {
+            break;
+        }
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    // now reverse the "bad block" and try to write the file again until we
+    // run out of space
+    lfs_testbd_setwear(&cfg, fileblock, 0) => 0;
+    lfs_file_open(&lfs, &file, "ghost", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    strcpy((char*)buffer, "chomp");
+    size = strlen("chomp");
+    while (true) {
+        lfs_ssize_t res = lfs_file_write(&lfs, &file, buffer, size);
+        assert(res == (lfs_ssize_t)size || res == LFS_ERR_NOSPC);
+        if (res == LFS_ERR_NOSPC) {
+            break;
+        }
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_unmount(&lfs) => 0;
+
+    // check that the disk isn't hurt
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &file, "pacman", LFS_O_RDONLY) => 0;
+    strcpy((char*)buffer, "waka");
+    size = strlen("waka");
+    for (lfs_size_t i = 0; i < filesize/size; i++) {
+        uint8_t rbuffer[4];
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
+
+
 # Below, I don't like these tests. They're fragile and depend _heavily_
 # on the geometry of the block device. But they are valuable. Eventually they
 # should be removed and replaced with generalized tests.

tests/test_dirs.toml

@@ -246,8 +246,6 @@ code = '''
                 LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
         lfs_file_close(&lfs, &file) => 0;
     }
-    // TODO rm me
-    lfs_mkdir(&lfs, "a") => 0;
     lfs_unmount(&lfs) => 0;
 
     lfs_mount(&lfs, &cfg) => 0;
@@ -258,9 +256,6 @@ code = '''
     lfs_dir_read(&lfs, &dir, &info) => 1;
     assert(info.type == LFS_TYPE_DIR);
     assert(strcmp(info.name, "..") == 0);
-    lfs_dir_read(&lfs, &dir, &info) => 1;
-    assert(info.type == LFS_TYPE_DIR);
-    assert(strcmp(info.name, "a") == 0);
     for (int i = 0; i < N; i++) {
         sprintf(path, "file%03d", i);
         lfs_dir_read(&lfs, &dir, &info) => 1;

tests/test_evil.toml

@@ -151,6 +151,7 @@ code = '''
             LFS_MKTAG(0x700, 0x3ff, 0),
             LFS_MKTAG(LFS_TYPE_STRUCT, 1, sizeof(struct lfs_ctz)), &ctz)
                 => LFS_MKTAG(LFS_TYPE_CTZSTRUCT, 1, sizeof(struct lfs_ctz));
+    lfs_ctz_fromle32(&ctz);
     // rewrite block to contain bad pointer
     uint8_t bbuffer[LFS_BLOCK_SIZE];
     cfg.read(&cfg, ctz.head, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
@@ -245,6 +246,7 @@ code = '''
             LFS_MKTAG(0x7ff, 0x3ff, 0),
             LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair)), pair)
                 => LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair));
+    lfs_pair_fromle32(pair);
     // change tail-pointer to point to root
     lfs_dir_fetch(&lfs, &mdir, pair) => 0;
     lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
@@ -274,6 +276,7 @@ code = '''
             LFS_MKTAG(0x7ff, 0x3ff, 0),
             LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair)), pair)
                 => LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair));
+    lfs_pair_fromle32(pair);
     // change tail-pointer to point to ourself
     lfs_dir_fetch(&lfs, &mdir, pair) => 0;
     lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(

tests/test_relocations.toml

@@ -148,7 +148,7 @@ code = '''
          # almost every tree operation needs a relocation
 reentrant = true
 # TODO fix this case, caused by non-DAG trees
-#if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
+if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
 define = [
     {FILES=6,  DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
     {FILES=26, DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
@@ -210,7 +210,7 @@ code = '''
 [[case]] # reentrant testing for relocations, but now with random renames!
 reentrant = true
 # TODO fix this case, caused by non-DAG trees
-#if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
+if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
 define = [
     {FILES=6,  DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
     {FILES=26, DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},