Switched to separate-tag encoding of forward-looking CRCs

Previously forward-looking CRCs was just two new CRC types, one for
commits with forward-looking CRCs, one without. These both contained the
CRC needed to complete the current commit (note that the commit CRC
must come last!).

         [--   32   --|--   32   --|--   32   --|--   32   --]
with:    [  crc3 tag  | nprog size |  nprog crc | commit crc ]
without: [  crc2 tag  | commit crc ]

This meant there had to be several checks for the two possible structure
sizes, messying up the implementation.

         [--   32   --|--   32   --|--   32   --|--   32   --|--   32   --]
with:    [nprogcrc tag| nprog size |  nprog crc | commit tag | commit crc ]
without: [ commit tag | commit crc ]

But we already have a mechanism for storing optional metadata! The
different metadata tags! So why not use a separate tage for the
forward-looking CRC, separate from the commit CRC?

I wasn't sure this would actually help that much, there are still
necessary conditions for wether or not a forward-looking CRC is there,
but in the end it simplified the code quite nicely, and resulted in a ~200 byte
code-cost saving.

.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:

README.md

@@ -221,6 +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.
@@ -250,3 +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/

bd/lfs_filebd.c

@@ -80,11 +80,6 @@ int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
     LFS_ASSERT(size % cfg->read_size == 0);
     LFS_ASSERT(block < cfg->block_count);
 
-    // zero for reproducability (in case file is truncated)
-    if (bd->cfg->erase_value != -1) {
-        memset(buffer, bd->cfg->erase_value, size);
-    }
-
     // read
     off_t res1 = lseek(bd->fd,
             (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
@@ -101,6 +96,11 @@ int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
         return err;
     }
 
+    // file truncated? zero for reproducability
+    if ((lfs_size_t)res2 < size) {
+        memset((uint8_t*)buffer + res2, 0, size-res2);
+    }
+
     LFS_FILEBD_TRACE("lfs_filebd_read -> %d", 0);
     return 0;
 }

bd/lfs_rambd.c

@@ -32,11 +32,8 @@ int lfs_rambd_createcfg(const struct lfs_config *cfg,
         }
     }
 
-    // zero for reproducability?
-    if (bd->cfg->erase_value != -1) {
-        memset(bd->buffer, bd->cfg->erase_value,
-                cfg->block_size * cfg->block_count);
-    }
+    // zero for reproducability (this matches filebd)
+    memset(bd->buffer, 0, cfg->block_size * cfg->block_count);
 
     LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", 0);
     return 0;

bd/lfs_testbd.c

@@ -207,7 +207,7 @@ 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);
         }
@@ -254,7 +254,7 @@ 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.h

@@ -22,7 +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 0x00020002
+#define LFS_VERSION 0x00020003
 #define LFS_VERSION_MAJOR (0xffff & (LFS_VERSION >> 16))
 #define LFS_VERSION_MINOR (0xffff & (LFS_VERSION >>  0))
 
@@ -54,7 +54,7 @@ typedef uint32_t lfs_block_t;
 
 // Maximum size of a file in bytes, may be redefined to limit to support other
 // drivers. Limited on disk to <= 4294967296. However, above 2147483647 the
-// functions _lfs_file_seek, _lfs_file_size, and _lfs_file_tell will return
+// functions lfs_file_seek, lfs_file_size, and lfs_file_tell will return
 // incorrect values due to using signed integers. Stored in superblock and
 // must be respected by other littlefs drivers.
 #ifndef LFS_FILE_MAX
@@ -85,9 +85,6 @@ enum lfs_error {
     LFS_ERR_NOMEM       = -12,  // No more memory available
     LFS_ERR_NOATTR      = -61,  // No data/attr available
     LFS_ERR_NAMETOOLONG = -36,  // File name too long
-#if LFS_THREAD_SAFE
-    LFS_ERR_LOCK        = -23,  // Failed to aquire lock
-#endif
 };
 
 // File types
@@ -116,6 +113,8 @@ enum lfs_type {
     LFS_TYPE_SOFTTAIL       = 0x600,
     LFS_TYPE_HARDTAIL       = 0x601,
     LFS_TYPE_MOVESTATE      = 0x7ff,
+    LFS_TYPE_COMMITCRC      = 0x502,
+    LFS_TYPE_NPROGCRC       = 0x5ff,
 
     // internal chip sources
     LFS_FROM_NOOP           = 0x000,
@@ -127,20 +126,25 @@ enum lfs_type {
 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
@@ -178,7 +182,7 @@ struct lfs_config {
     // are propogated to the user.
     int (*sync)(const struct lfs_config *c);
 
-    #if LFS_THREAD_SAFE
+#ifdef LFS_THREADSAFE
     // Lock the underlying block device. Negative error codes
     // are propogated to the user.
     int (*lock)(const struct lfs_config *c);
@@ -186,7 +190,7 @@ struct lfs_config {
     // Unlock the underlying block device. Negative error codes
     // are propogated to the user.
     int (*unlock)(const struct lfs_config *c);
-    #endif
+#endif
 
     // Minimum size of a block read. All read operations will be a
     // multiple of this value.
@@ -413,6 +417,7 @@ 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
@@ -420,7 +425,8 @@ typedef struct lfs {
 // be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
-int _lfs_format(lfs_t *lfs, const struct lfs_config *config);
+int lfs_format(lfs_t *lfs, const struct lfs_config *config);
+#endif
 
 // Mounts a littlefs
 //
@@ -430,35 +436,39 @@ int _lfs_format(lfs_t *lfs, const struct lfs_config *config);
 // be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
-int _lfs_mount(lfs_t *lfs, const struct lfs_config *config);
+int lfs_mount(lfs_t *lfs, const struct lfs_config *config);
 
 // Unmounts a littlefs
 //
 // Does nothing besides releasing any allocated resources.
 // Returns a negative error code on failure.
-int _lfs_unmount(lfs_t *lfs);
+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);
+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.
 // If the destination is a directory, the directory must be empty.
 //
 // Returns a negative error code on failure.
-int _lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath);
+int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath);
+#endif
 
 // Find info about a file or directory
 //
 // Fills out the info structure, based on the specified file or directory.
 // Returns a negative error code on failure.
-int _lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
+int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
 
 // Get a custom attribute
 //
@@ -472,9 +482,10 @@ int _lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
 // Note, the returned size is the size of the attribute on disk, irrespective
 // of the size of the buffer. This can be used to dynamically allocate a buffer
 // or check for existance.
-lfs_ssize_t _lfs_getattr(lfs_t *lfs, const char *path,
+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
@@ -482,15 +493,18 @@ lfs_ssize_t _lfs_getattr(lfs_t *lfs, const char *path,
 // implicitly created.
 //
 // Returns a negative error code on failure.
-int _lfs_setattr(lfs_t *lfs, const char *path,
+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);
+int lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type);
+#endif
 
 
 /// File operations ///
@@ -501,7 +515,7 @@ int _lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type);
 // are values from the enum lfs_open_flags that are bitwise-ored together.
 //
 // Returns a negative error code on failure.
-int _lfs_file_open(lfs_t *lfs, lfs_file_t *file,
+int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
         const char *path, int flags);
 
 // Open a file with extra configuration
@@ -514,7 +528,7 @@ int _lfs_file_open(lfs_t *lfs, lfs_file_t *file,
 // config struct must be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
-int _lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
+int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
         const char *path, int flags,
         const struct lfs_file_config *config);
 
@@ -524,86 +538,92 @@ int _lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
 // sync had been called and releases any allocated resources.
 //
 // Returns a negative error code on failure.
-int _lfs_file_close(lfs_t *lfs, lfs_file_t *file);
+int lfs_file_close(lfs_t *lfs, lfs_file_t *file);
 
 // Synchronize a file on storage
 //
 // Any pending writes are written out to storage.
 // Returns a negative error code on failure.
-int _lfs_file_sync(lfs_t *lfs, lfs_file_t *file);
+int lfs_file_sync(lfs_t *lfs, lfs_file_t *file);
 
 // Read data from file
 //
 // Takes a buffer and size indicating where to store the read data.
 // Returns the number of bytes read, or a negative error code on failure.
-lfs_ssize_t _lfs_file_read(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
 // actually be updated on the storage until either sync or close is called.
 //
 // 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,
+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
 //
 // The change in position is determined by the offset and whence flag.
 // Returns the new position of the file, or a negative error code on failure.
-lfs_soff_t _lfs_file_seek(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);
+int lfs_file_truncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size);
+#endif
 
 // Return the position of the file
 //
-// Equivalent to _lfs_file_seek(lfs, file, 0, LFS_SEEK_CUR)
+// Equivalent to lfs_file_seek(lfs, file, 0, LFS_SEEK_CUR)
 // Returns the position of the file, or a negative error code on failure.
-lfs_soff_t _lfs_file_tell(lfs_t *lfs, lfs_file_t *file);
+lfs_soff_t lfs_file_tell(lfs_t *lfs, lfs_file_t *file);
 
 // Change the position of the file to the beginning of the file
 //
-// Equivalent to _lfs_file_seek(lfs, file, 0, LFS_SEEK_SET)
+// Equivalent to lfs_file_seek(lfs, file, 0, LFS_SEEK_SET)
 // Returns a negative error code on failure.
-int _lfs_file_rewind(lfs_t *lfs, lfs_file_t *file);
+int lfs_file_rewind(lfs_t *lfs, lfs_file_t *file);
 
 // Return the size of the file
 //
-// Similar to _lfs_file_seek(lfs, file, 0, LFS_SEEK_END)
+// Similar to lfs_file_seek(lfs, file, 0, LFS_SEEK_END)
 // Returns the size of the file, or a negative error code on failure.
-lfs_soff_t _lfs_file_size(lfs_t *lfs, lfs_file_t *file);
+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);
+int lfs_mkdir(lfs_t *lfs, const char *path);
+#endif
 
 // Open a directory
 //
 // Once open a directory can be used with read to iterate over files.
 // Returns a negative error code on failure.
-int _lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path);
+int lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path);
 
 // Close a directory
 //
 // Releases any allocated resources.
 // Returns a negative error code on failure.
-int _lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir);
+int lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir);
 
 // Read an entry in the directory
 //
 // Fills out the info structure, based on the specified file or directory.
 // Returns a positive value on success, 0 at the end of directory,
 // or a negative error code on failure.
-int _lfs_dir_read(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info);
+int lfs_dir_read(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info);
 
 // Change the position of the directory
 //
@@ -611,7 +631,7 @@ int _lfs_dir_read(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info);
 // an absolute offset in the directory seek.
 //
 // Returns a negative error code on failure.
-int _lfs_dir_seek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off);
+int lfs_dir_seek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off);
 
 // Return the position of the directory
 //
@@ -619,12 +639,12 @@ int _lfs_dir_seek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off);
 // sense, but does indicate the current position in the directory iteration.
 //
 // Returns the position of the directory, or a negative error code on failure.
-lfs_soff_t _lfs_dir_tell(lfs_t *lfs, lfs_dir_t *dir);
+lfs_soff_t lfs_dir_tell(lfs_t *lfs, lfs_dir_t *dir);
 
 // Change the position of the directory to the beginning of the directory
 //
 // Returns a negative error code on failure.
-int _lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir);
+int lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir);
 
 
 /// Filesystem-level filesystem operations
@@ -635,7 +655,7 @@ int _lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir);
 // size may be larger than the filesystem actually is.
 //
 // Returns the number of allocated blocks, or a negative error code on failure.
-lfs_ssize_t _lfs_fs_size(lfs_t *lfs);
+lfs_ssize_t lfs_fs_size(lfs_t *lfs);
 
 // Traverse through all blocks in use by the filesystem
 //
@@ -644,12 +664,13 @@ lfs_ssize_t _lfs_fs_size(lfs_t *lfs);
 // blocks are in use or how much of the storage is available.
 //
 // Returns a negative error code on failure.
-int _lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
+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
 //
-// Behaves similarly to the _lfs_format function. Attempts to mount
+// Behaves similarly to the lfs_format function. Attempts to mount
 // the previous version of littlefs and update the filesystem so it can be
 // mounted with the current version of littlefs.
 //
@@ -658,106 +679,8 @@ int _lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
 // be zeroed for defaults and backwards compatibility.
 //
 // Returns a negative error code on failure.
-int _lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg);
+int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg);
 #endif
-
-#if LFS_THREAD_SAFE
-
-int _ts_lfs_format(lfs_t *lfs, const struct lfs_config *config);
-int _ts_lfs_mount(lfs_t *lfs, const struct lfs_config *config);
-int _ts_lfs_unmount(lfs_t *lfs);
-int _ts_lfs_remove(lfs_t *lfs, const char *path);
-int _ts_lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath);
-int _ts_lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
-lfs_ssize_t _ts_lfs_getattr(lfs_t *lfs, const char *path, uint8_t type, void *buffer, lfs_size_t size);
-int _ts_lfs_setattr(lfs_t *lfs, const char *path, uint8_t type, const void *buffer, lfs_size_t size);
-int _ts_lfs_removeattr(lfs_t *lfs, const char *path, uint8_t type);
-int _ts_lfs_file_open(lfs_t *lfs, lfs_file_t *file, const char *path, int flags);
-int _ts_lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file, const char *path, int flags, const struct lfs_file_config *config);
-int _ts_lfs_file_close(lfs_t *lfs, lfs_file_t *file);
-int _ts_lfs_file_sync(lfs_t *lfs, lfs_file_t *file);
-lfs_ssize_t _ts_lfs_file_read(lfs_t *lfs, lfs_file_t *file, void *buffer, lfs_size_t size);
-lfs_ssize_t _ts_lfs_file_write(lfs_t *lfs, lfs_file_t *file, const void *buffer, lfs_size_t size);
-lfs_soff_t _ts_lfs_file_seek(lfs_t *lfs, lfs_file_t *file, lfs_soff_t off, int whence);
-int _ts_lfs_file_truncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size);
-lfs_soff_t _ts_lfs_file_tell(lfs_t *lfs, lfs_file_t *file);
-int _ts_lfs_file_rewind(lfs_t *lfs, lfs_file_t *file);
-lfs_soff_t _ts_lfs_file_size(lfs_t *lfs, lfs_file_t *file);
-int _ts_lfs_mkdir(lfs_t *lfs, const char *path);
-int _ts_lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path);
-int _ts_lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir);
-int _ts_lfs_dir_read(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info);
-int _ts_lfs_dir_seek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off);
-lfs_soff_t _ts_lfs_dir_tell(lfs_t *lfs, lfs_dir_t *dir);
-int _ts_lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir);
-lfs_ssize_t _ts_lfs_fs_size(lfs_t *lfs);
-int _ts_lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
-int _ts_lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg);
-
-#define lfs_format _ts_lfs_format
-#define lfs_mount _ts_lfs_mount
-#define lfs_unmount _ts_lfs_unmount
-#define lfs_remove _ts_lfs_remove
-#define lfs_rename _ts_lfs_rename
-#define lfs_stat _ts_lfs_stat
-#define lfs_getattr _ts_lfs_getattr
-#define lfs_setattr _ts_lfs_setattr
-#define lfs_removeattr _ts_lfs_removeattr
-#define lfs_file_open _ts_lfs_file_open
-#define lfs_file_opencfg _ts_lfs_file_opencfg
-#define lfs_file_close _ts_lfs_file_close
-#define lfs_file_sync _ts_lfs_file_sync
-#define lfs_file_read _ts_lfs_file_read
-#define lfs_file_write _ts_lfs_file_write
-#define lfs_file_seek _ts_lfs_file_seek
-#define lfs_file_truncate _ts_lfs_file_truncate
-#define lfs_file_tell _ts_lfs_file_tell
-#define lfs_file_rewind _ts_lfs_file_rewind
-#define lfs_file_size _ts_lfs_file_size
-#define lfs_mkdir _ts_lfs_mkdir
-#define lfs_dir_open _ts_lfs_dir_open
-#define lfs_dir_close _ts_lfs_dir_close
-#define lfs_dir_read _ts_lfs_dir_read
-#define lfs_dir_seek _ts_lfs_dir_seek
-#define lfs_dir_tell _ts_lfs_dir_tell
-#define lfs_dir_rewind _ts_lfs_dir_rewind
-#define lfs_fs_size _ts_lfs_fs_size
-#define lfs_fs_traverse _ts_lfs_fs_traverse
-#define lfs_migrate _ts_lfs_migrate
-
-#else
-
-#define lfs_format _lfs_format
-#define lfs_mount _lfs_mount
-#define lfs_unmount _lfs_unmount
-#define lfs_remove _lfs_remove
-#define lfs_rename _lfs_rename
-#define lfs_stat _lfs_stat
-#define lfs_getattr _lfs_getattr
-#define lfs_setattr _lfs_setattr
-#define lfs_removeattr _lfs_removeattr
-#define lfs_file_open _lfs_file_open
-#define lfs_file_opencfg _lfs_file_opencfg
-#define lfs_file_close _lfs_file_close
-#define lfs_file_sync _lfs_file_sync
-#define lfs_file_read _lfs_file_read
-#define lfs_file_write _lfs_file_write
-#define lfs_file_seek _lfs_file_seek
-#define lfs_file_truncate _lfs_file_truncate
-#define lfs_file_tell _lfs_file_tell
-#define lfs_file_rewind _lfs_file_rewind
-#define lfs_file_size _lfs_file_size
-#define lfs_mkdir _lfs_mkdir
-#define lfs_dir_open _lfs_dir_open
-#define lfs_dir_close _lfs_dir_close
-#define lfs_dir_read _lfs_dir_read
-#define lfs_dir_seek _lfs_dir_seek
-#define lfs_dir_tell _lfs_dir_tell
-#define lfs_dir_rewind _lfs_dir_rewind
-#define lfs_fs_size _lfs_fs_size
-#define lfs_fs_traverse _lfs_fs_traverse
-#define lfs_migrate _lfs_migrate
-
 #endif
 
 

lfs_util.h

@@ -43,9 +43,6 @@ extern "C"
 {
 #endif
 
-#ifndef LFS_THREAD_SAFE
-#define LFS_THREAD_SAFE 0
-#endif
 
 // Macros, may be replaced by system specific wrappers. Arguments to these
 // macros must not have side-effects as the macros can be removed for a smaller

scripts/readmdir.py

@@ -24,6 +24,7 @@ TAG_TYPES = {
     'gstate':       (0x700, 0x700),
     'movestate':    (0x7ff, 0x7ff),
     'crc':          (0x700, 0x500),
+    'nprogcrc':     (0x7ff, 0x5ff),
 }
 
 class Tag:
@@ -99,7 +100,16 @@ class Tag:
         return struct.unpack('b', struct.pack('B', self.chunk))[0]
 
     def is_(self, type):
-        return (self.type & TAG_TYPES[type][0]) == TAG_TYPES[type][1]
+        try:
+            if ' ' in type:
+                type1, type3 = type.split()
+                return (self.is_(type1) and
+                    (self.type & ~TAG_TYPES[type1][0]) == int(type3, 0))
+
+            return self.type == int(type, 0)
+
+        except (ValueError, KeyError):
+            return (self.type & TAG_TYPES[type][0]) == TAG_TYPES[type][1]
 
     def mkmask(self):
         return Tag(
@@ -109,14 +119,20 @@ class Tag:
 
     def chid(self, nid):
         ntag = Tag(self.type, nid, self.size)
-        if hasattr(self, 'off'):  ntag.off  = self.off
-        if hasattr(self, 'data'): ntag.data = self.data
-        if hasattr(self, 'crc'):  ntag.crc  = self.crc
+        if hasattr(self, 'off'):    ntag.off    = self.off
+        if hasattr(self, 'data'):   ntag.data   = self.data
+        if hasattr(self, 'crc'):    ntag.crc    = self.crc
+        if hasattr(self, 'erased'): ntag.erased = self.erased
         return ntag
 
     def typerepr(self):
-        if self.is_('crc') and getattr(self, 'crc', 0xffffffff) != 0xffffffff:
-            return 'crc (bad)'
+        if (self.is_('crc') and not self.is_('nprogcrc') and
+                getattr(self, 'crc', 0xffffffff) != 0xffffffff):
+            crc_status = ' (bad)'
+        elif self.is_('nprogcrc') and getattr(self, 'erased', False):
+            crc_status = ' (era)'
+        else:
+            crc_status = ''
 
         reverse_types = {v: k for k, v in TAG_TYPES.items()}
         for prefix in range(12):
@@ -124,12 +140,12 @@ class Tag:
             if (mask, self.type & mask) in reverse_types:
                 type = reverse_types[mask, self.type & mask]
                 if prefix > 0:
-                    return '%s %#0*x' % (
-                        type, prefix//4, self.type & ((1 << prefix)-1))
+                    return '%s %#x%s' % (
+                        type, self.type & ((1 << prefix)-1), crc_status)
                 else:
-                    return type
+                    return '%s%s' % (type, crc_status)
         else:
-            return '%02x' % self.type
+            return '%02x%s' % (self.type, crc_status)
 
     def idrepr(self):
         return repr(self.id) if self.id != 0x3ff else '.'
@@ -172,6 +188,8 @@ class MetadataPair:
 
         self.rev, = struct.unpack('<I', block[0:4])
         crc = binascii.crc32(block[0:4])
+        etag = None
+        estate = None
 
         # parse tags
         corrupt = False
@@ -182,11 +200,11 @@ class MetadataPair:
         while len(block) - off >= 4:
             ntag, = struct.unpack('>I', block[off:off+4])
 
-            tag = Tag(int(tag) ^ ntag)
+            tag = Tag((int(tag) ^ ntag) & 0x7fffffff)
             tag.off = off + 4
             tag.data = block[off+4:off+tag.dsize]
-            if tag.is_('crc'):
-                crc = binascii.crc32(block[off:off+4+4], crc)
+            if tag.is_('crc') and not tag.is_('nprogcrc'):
+                crc = binascii.crc32(block[off:off+2*4], crc)
             else:
                 crc = binascii.crc32(block[off:off+tag.dsize], crc)
             tag.crc = crc
@@ -194,16 +212,29 @@ class MetadataPair:
 
             self.all_.append(tag)
 
-            if tag.is_('crc'):
+            if tag.is_('nprogcrc') and len(tag.data) == 8:
+                etag = tag
+                estate = struct.unpack('<II', tag.data)
+            elif tag.is_('crc'):
                 # is valid commit?
                 if crc != 0xffffffff:
                     corrupt = True
                 if not corrupt:
                     self.log = self.all_.copy()
+                    # end of commit?
+                    if estate:
+                        esize, ecrc = estate
+                        dcrc = 0xffffffff ^ binascii.crc32(block[off:off+esize])
+                        if ecrc == dcrc:
+                            etag.erased = True
+                            corrupt = True
+                    elif not (tag.is_('crc 0x0') or tag.is_('crc 0x1')):
+                        corrupt = True
 
                 # reset tag parsing
                 crc = 0
-                tag = Tag(int(tag) ^ ((tag.type & 1) << 31))
+                etag = None
+                estate = None
 
         # find active ids
         self.ids = list(it.takewhile(
@@ -280,7 +311,7 @@ class MetadataPair:
         f.write('\n')
 
         for tag in tags:
-            f.write("%08x: %08x  %-13s %4s %4s" % (
+            f.write("%08x: %08x  %-14s %3s %4s" % (
                 tag.off, tag,
                 tag.typerepr(), tag.idrepr(), tag.sizerepr()))
             if truncate:

scripts/readtree.py

@@ -106,7 +106,7 @@ 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
     print("gstate 0x%s" % ''.join('%02x' % c for c in gstate))

tests/test_powerloss.toml

@@ -0,0 +1,172 @@
+# There are already a number of tests that test general operations under
+# power-loss (see the reentrant attribute). These tests are for explicitly
+# testing specific corner cases.
+
+[[case]] # only a revision count
+code = '''
+    lfs_format(&lfs, &cfg) => 0;
+
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mkdir(&lfs, "notebook") => 0;
+    lfs_file_open(&lfs, &file, "notebook/paper",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+    strcpy((char*)buffer, "hello");
+    size = strlen("hello");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_sync(&lfs, &file) => 0;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    char rbuffer[256];
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // get pair/rev count
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_dir_open(&lfs, &dir, "notebook") => 0;
+    lfs_block_t pair[2] = {dir.m.pair[0], dir.m.pair[1]};
+    uint32_t rev = dir.m.rev;
+    lfs_dir_close(&lfs, &dir) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // write just the revision count
+    uint8_t bbuffer[LFS_BLOCK_SIZE];
+    cfg.read(&cfg, pair[1], 0, bbuffer, LFS_BLOCK_SIZE) => 0;
+
+    memcpy(bbuffer, &(uint32_t){lfs_tole32(rev+1)}, sizeof(uint32_t));
+
+    cfg.erase(&cfg, pair[1]) => 0;
+    cfg.prog(&cfg, pair[1], 0, bbuffer, LFS_BLOCK_SIZE) => 0;
+
+    lfs_mount(&lfs, &cfg) => 0;
+
+    // can read?
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    // can write?
+    lfs_file_open(&lfs, &file, "notebook/paper",
+            LFS_O_WRONLY | LFS_O_APPEND) => 0;
+    strcpy((char*)buffer, "goodbye");
+    size = strlen("goodbye");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_sync(&lfs, &file) => 0;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    strcpy((char*)buffer, "hello");
+    size = strlen("hello");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    strcpy((char*)buffer, "goodbye");
+    size = strlen("goodbye");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # partial prog, may not be byte in order!
+if = "LFS_PROG_SIZE < LFS_BLOCK_SIZE"
+define.BYTE_OFF = ["0", "LFS_PROG_SIZE-1", "LFS_PROG_SIZE/2"]
+define.BYTE_VALUE = [0x33, 0xcc]
+in = "lfs.c"
+code = '''
+    lfs_format(&lfs, &cfg) => 0;
+
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mkdir(&lfs, "notebook") => 0;
+    lfs_file_open(&lfs, &file, "notebook/paper",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+    strcpy((char*)buffer, "hello");
+    size = strlen("hello");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_sync(&lfs, &file) => 0;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    char rbuffer[256];
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // imitate a partial prog, value should not matter, if littlefs
+    // doesn't notice the partial prog testbd will assert
+
+    // get offset to next prog
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_dir_open(&lfs, &dir, "notebook") => 0;
+    lfs_block_t block = dir.m.pair[0];
+    lfs_off_t off = dir.m.off;
+    lfs_dir_close(&lfs, &dir) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // tweak byte
+    uint8_t bbuffer[LFS_BLOCK_SIZE];
+    cfg.read(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
+
+    bbuffer[off + BYTE_OFF] = BYTE_VALUE;
+
+    cfg.erase(&cfg, block) => 0;
+    cfg.prog(&cfg, block, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
+
+    lfs_mount(&lfs, &cfg) => 0;
+
+    // can read?
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    // can write?
+    lfs_file_open(&lfs, &file, "notebook/paper",
+            LFS_O_WRONLY | LFS_O_APPEND) => 0;
+    strcpy((char*)buffer, "goodbye");
+    size = strlen("goodbye");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+        lfs_file_sync(&lfs, &file) => 0;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_file_open(&lfs, &file, "notebook/paper", LFS_O_RDONLY) => 0;
+    strcpy((char*)buffer, "hello");
+    size = strlen("hello");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    strcpy((char*)buffer, "goodbye");
+    size = strlen("goodbye");
+    for (int i = 0; i < 5; i++) {
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_unmount(&lfs) => 0;
+'''