TMPFS: Code complete, but not yet functional

ChangeLog

@@ -11017,4 +11017,7 @@
 	  temporary RAM file file system (2015-10-0i8).
 	* tools/: Add crappy style checking tool nxstyle.c.  See thee tools/
 	  README file for more info (2015-10-08).
-
+	* stm32 F4:  Fix some TIM12 pin mappings.  From Max Kriegleder
+	  (2015-10-9).
+	* fs/tmpfs: TMPFS file system is code complete, but not yet functional
+	  (2015-10-9).

arch

@@ -1 +1 @@
-Subproject commit 0b7bf8249b1b96f5e31597b5242db222a2c29f73
+Subproject commit 00acafcbb154a076f60413eb75249c5b68c6c316

fs/Kconfig

@@ -57,6 +57,7 @@ source fs/fat/Kconfig
 source fs/nfs/Kconfig
 source fs/nxffs/Kconfig
 source fs/romfs/Kconfig
+source fs/tmpfs/Kconfig
 source fs/smartfs/Kconfig
 source fs/binfs/Kconfig
 source fs/procfs/Kconfig

fs/Makefile

@@ -64,6 +64,7 @@ ifneq ($(CONFIG_DISABLE_MOUNTPOINT),y)
 include mount/Make.defs
 include fat/Make.defs
 include romfs/Make.defs
+include tmpfs/Make.defs
 include nxffs/Make.defs
 include nfs/Make.defs
 include smartfs/Make.defs

fs/mount/fs_mount.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * fs/mount/fs_mount.c
  *
- *   Copyright (C) 2007-2009, 2011-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2013, 2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -77,7 +77,8 @@
 /* These file systems do not require block drivers */
 
 #if defined(CONFIG_FS_NXFFS) || defined(CONFIG_FS_BINFS) || \
-    defined(CONFIG_FS_PROCFS) || defined(CONFIG_NFS)
+    defined(CONFIG_FS_PROCFS) || defined(CONFIG_NFS) || \
+    defined(CONFIG_FS_TMPFS)
 #  define NONBDFS_SUPPORT
 #endif
 
@@ -102,6 +103,9 @@ extern const struct mountpt_operations fat_operations;
 #ifdef CONFIG_FS_ROMFS
 extern const struct mountpt_operations romfs_operations;
 #endif
+#ifdef CONFIG_FS_TMPFS
+extern const struct mountpt_operations tmpfs_operations;
+#endif
 #ifdef CONFIG_FS_SMARTFS
 extern const struct mountpt_operations smartfs_operations;
 #endif
@@ -140,6 +144,9 @@ static const struct fsmap_t g_nonbdfsmap[] =
 #ifdef CONFIG_FS_NXFFS
     { "nxffs", &nxffs_operations },
 #endif
+#ifdef CONFIG_FS_TMPFS
+    { "tmpfs", &tmpfs_operations },
+#endif
 #ifdef CONFIG_NFS
     { "nfs", &nfs_operations },
 #endif

fs/tmpfs/fs_tmpfs.h

@@ -47,8 +47,6 @@
 
 #include <nuttx/fs/fs.h>
 
-#ifndef CONFIG_DISABLE_MOUNTPOINT
-
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
@@ -56,6 +54,10 @@
 
 #define TMPFS_BLOCKSIZE   512
 
+/* Indicates that there is no holder of the re-entrant semaphore */
+
+#define TMPFS_NO_HOLDER   -1
+
 /* Bit definitions for file object flags */
 
 #define TFO_FLAG_UNLINKED (1 << 0)  /* Bit 0: File is unlinked */
@@ -82,22 +84,33 @@ enum tmpfs_foreach_e
   TMPFS_UNLINKED         /* Only the directory entry was deleted */
 };
 
-/* The generic form of a TMPFS memory object */
+/* Re-entrant semaphore */
 
-struct tmpfs_object_s
+struct tmpfs_sem_s
 {
-  size_t   to_alloc;     /* Allocated size of the memory object */
+  sem_t    ts_sem;       /* The actual semaphore */
-  uint8_t  to_type;      /* See enum tmpfs_objtype_e */
+  pid_t    ts_holder;    /* Current older (-1 if not held) */
-  uint8_t  to_refs;      /* Reference count */
+  uint16_t ts_count;     /* Number of counts held */
-  sem_t    to_exclsem;   /* Supports exclusive access to the object */
 };
 
 /* The form of one directory entry */
 
 struct tmpfs_dirent_s
 {
-  FAR struct tmpfs_object_s *rde_object;
+  FAR struct tmpfs_object_s *tde_object;
-  FAR char *rde_name;
+  FAR char *tde_name;
+};
+
+/* The generic form of a TMPFS memory object */
+
+struct tmpfs_object_s
+{
+  FAR struct tmpfs_dirent_s *to_dirent;
+  struct tmpfs_sem_s to_exclsem;
+
+  size_t   to_alloc;     /* Allocated size of the memory object */
+  uint8_t  to_type;      /* See enum tmpfs_objtype_e */
+  uint8_t  to_refs;      /* Reference count */
 };
 
 /* The form of a directory memory object */
@@ -106,10 +119,12 @@ struct tmpfs_directory_s
 {
   /* First fields must match common TMPFS object layout */
 
+  FAR struct tmpfs_dirent_s *tdo_dirent;
+  struct tmpfs_sem_s tdo_exclsem;
+
   size_t   tdo_alloc;    /* Allocated size of the directory object */
   uint8_t  tdo_type;     /* See enum tmpfs_objtype_e */
   uint8_t  tdo_refs;     /* Reference count */
-  sem_t    tdo_exclsem;  /* Supports exclusive access to the directory */
 
   /* Remaining fields are unique to a directory object */
 
@@ -132,10 +147,12 @@ struct tmpfs_file_s
 {
   /* First fields must match common TMPFS object layout */
 
+  FAR struct tmpfs_dirent_s *tfo_dirent;
+  struct tmpfs_sem_s tfo_exclsem;
+
   size_t   tfo_alloc;    /* Allocated size of the file object */
   uint8_t  tfo_type;     /* See enum tmpfs_objtype_e */
   uint8_t  tfo_refs;     /* Reference count */
-  sem_t    tfo_exclsem;  /* Supports exclusive access to the file */
 
   /* Remaining fields are unique to a directory object */
 
@@ -153,8 +170,7 @@ struct tmpfs_s
   /* The root directory */
 
   FAR struct tmpfs_directory_s *tfs_root;
-
+  struct tmpfs_sem_s tfs_exclsem;
-  sem_t tfs_exclsem;     /* Supports exclusive access to the file system */
 };
 
 /* This is the type used the tmpfs_statfs_callout to accumulate memory usage */