Squashed commit of the following:

fs/smartfs:  Add logic needed to ftruncate to shrink a file to any arbitrary size.
    fs/smartfs:  Repartition some functionality to better fit in new ftruncate features.

configs/sim/src/sim_bringup.c

@@ -147,7 +147,7 @@ int sim_bringup(void)
 
 #if defined(CONFIG_MTD_SMART) && defined(CONFIG_FS_SMARTFS)
           /* Initialize a SMART Flash block device and bind it to the MTD
-           * ./device.
+           * device.
            */
 
           smart_initialize(0, mtd, NULL);

fs/smartfs/Kconfig

@@ -16,6 +16,7 @@ if FS_SMARTFS
 config SMARTFS_ERASEDSTATE
 	hex "FLASH erased state"
 	default 0xff
+	range 0x00 0xff
 	---help---
 		The erased state of FLASH.
 		This must have one of the values of 0xff or 0x00.

fs/smartfs/smartfs.h

@@ -340,7 +340,7 @@ struct smartfs_mountpt_s
  ****************************************************************************/
 
 /****************************************************************************
- * Internal function prototypes
+ * Public Functions
  ****************************************************************************/
 
 /* Semaphore access for internal use */
@@ -354,28 +354,37 @@ struct smartfs_mountpt_s;
 
 /* Utility functions */
 
-int smartfs_mount(struct smartfs_mountpt_s *fs, bool writeable);
+int smartfs_mount(FAR struct smartfs_mountpt_s *fs, bool writeable);
 
-int smartfs_unmount(struct smartfs_mountpt_s *fs);
+int smartfs_unmount(FAR struct smartfs_mountpt_s *fs);
 
-int smartfs_finddirentry(struct smartfs_mountpt_s *fs,
-        struct smartfs_entry_s *direntry, const char *relpath,
-        uint16_t *parentdirsector, const char **filename);
+int smartfs_finddirentry(FAR struct smartfs_mountpt_s *fs,
+        FAR struct smartfs_entry_s *direntry, FAR const char *relpath,
+        FAR uint16_t *parentdirsector, FAR const char **filename);
 
-int smartfs_createentry(struct smartfs_mountpt_s *fs,
-        uint16_t parentdirsector, const char* filename,
+int smartfs_createentry(FAR struct smartfs_mountpt_s *fs,
+        uint16_t parentdirsector, FAR const char* filename,
         uint16_t type,
-        mode_t mode, struct smartfs_entry_s *direntry,
+        mode_t mode, FAR struct smartfs_entry_s *direntry,
         uint16_t sectorno, FAR struct smartfs_ofile_s *sf);
 
-int smartfs_deleteentry(struct smartfs_mountpt_s *fs,
-        struct smartfs_entry_s *entry);
+int smartfs_deleteentry(FAR struct smartfs_mountpt_s *fs,
+        FAR struct smartfs_entry_s *entry);
 
-int smartfs_countdirentries(struct smartfs_mountpt_s *fs,
-        struct smartfs_entry_s *entry);
+int smartfs_countdirentries(FAR struct smartfs_mountpt_s *fs,
+        FAR struct smartfs_entry_s *entry);
 
-int smartfs_truncatefile(struct smartfs_mountpt_s *fs,
-        struct smartfs_entry_s *entry, FAR struct smartfs_ofile_s *sf);
+int smartfs_sync_internal(FAR struct smartfs_mountpt_s *fs,
+        FAR struct smartfs_ofile_s *sf);
+
+off_t smartfs_seek_internal(FAR struct smartfs_mountpt_s *fs,
+        FAR struct smartfs_ofile_s *sf, off_t offset, int whence);
+
+int smartfs_shrinkfile(FAR struct smartfs_mountpt_s *fs,
+        FAR struct smartfs_ofile_s *sf, off_t length);
+
+int smartfs_extendfile(FAR struct smartfs_mountpt_s *fs,
+        FAR struct smartfs_ofile_s *sf, off_t length);
 
 uint16_t smartfs_rdle16(FAR const void *val);