fs/jffs/jffs_fm.h

   1 /*
   2  * JFFS -- Journaling Flash File System, Linux implementation.
   3  *
   4  * Copyright (C) 1999, 2000  Axis Communications AB.
   5  *
   6  * Created by Finn Hakansson <finn@axis.com>.
   7  *
   8  * This is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * $Id: jffs_fm.h,v 1.13 2001/01/11 12:03:25 dwmw2 Exp $
  14  *
  15  * Ported to Linux 2.3.x and MTD:
  16  * Copyright (C) 2000  Alexander Larsson (alex@cendio.se), Cendio Systems AB
  17  *
  18  */
  19
  20 #ifndef __LINUX_JFFS_FM_H__
  21 #define __LINUX_JFFS_FM_H__
  22
  23 #include <linux/types.h>
  24 #include <linux/jffs.h>
  25 #include <linux/mtd/mtd.h>
  26 #include <linux/config.h>
  27
  28 /* The alignment between two nodes in the flash memory.  */
  29 #define JFFS_ALIGN_SIZE 4
  30
  31 /* Mark the on-flash space as obsolete when appropriate.  */
  32 #define JFFS_MARK_OBSOLETE 0
  33
  34 #ifndef CONFIG_JFFS_FS_VERBOSE
  35 #define CONFIG_JFFS_FS_VERBOSE 1
  36 #endif
  37
  38 #if CONFIG_JFFS_FS_VERBOSE > 0
  39 #define D(x) x
  40 #define D1(x) D(x)
  41 #else
  42 #define D(x)
  43 #define D1(x)
  44 #endif
  45
  46 #if CONFIG_JFFS_FS_VERBOSE > 1
  47 #define D2(x) D(x)
  48 #else
  49 #define D2(x)
  50 #endif
  51
  52 #if CONFIG_JFFS_FS_VERBOSE > 2
  53 #define D3(x) D(x)
  54 #else
  55 #define D3(x)
  56 #endif
  57
  58 #define ASSERT(x) x
  59
  60 /* How many padding bytes should be inserted between two chunks of data
  61    on the flash?  */
  62 #define JFFS_GET_PAD_BYTES(size) ( (JFFS_ALIGN_SIZE-1) & -(__u32)(size) )
  63 #define JFFS_PAD(size) ( (size + (JFFS_ALIGN_SIZE-1)) & ~(JFFS_ALIGN_SIZE-1) )
  64
  65
  66
  67 struct jffs_node_ref
  68 {
  69         struct jffs_node *node;
  70         struct jffs_node_ref *next;
  71 };
  72
  73
  74 /* The struct jffs_fm represents a chunk of data in the flash memory.  */
  75 struct jffs_fm
  76 {
  77         __u32 offset;
  78         __u32 size;
  79         struct jffs_fm *prev;
  80         struct jffs_fm *next;
  81         struct jffs_node_ref *nodes; /* USED if != 0.  */
  82 };
  83
  84 struct jffs_fmcontrol
  85 {
  86         __u32 flash_size;
  87         __u32 used_size;
  88         __u32 dirty_size;
  89         __u32 free_size;
  90         __u32 sector_size;
  91         __u32 min_free_size;  /* The minimum free space needed to be able
  92                                  to perform garbage collections.  */
  93         __u32 max_chunk_size; /* The maximum size of a chunk of data.  */
  94         struct mtd_info *mtd;
  95         struct jffs_control *c;
  96         struct jffs_fm *head;
  97         struct jffs_fm *tail;
  98         struct jffs_fm *head_extra;
  99         struct jffs_fm *tail_extra;
 100         struct semaphore biglock;
 101 };
 102
 103 /* Notice the two members head_extra and tail_extra in the jffs_control
 104    structure above. Those are only used during the scanning of the flash
 105    memory; while the file system is being built. If the data in the flash
 106    memory is organized like
 107
 108       +----------------+------------------+----------------+
 109       |  USED / DIRTY  |       FREE       |  USED / DIRTY  |
 110       +----------------+------------------+----------------+
 111
 112    then the scan is split in two parts. The first scanned part of the
 113    flash memory is organized through the members head and tail. The
 114    second scanned part is organized with head_extra and tail_extra. When
 115    the scan is completed, the two lists are merged together. The jffs_fm
 116    struct that head_extra references is the logical beginning of the
 117    flash memory so it will be referenced by the head member.  */
 118
 119
 120
 121 struct jffs_fmcontrol *jffs_build_begin(struct jffs_control *c, int unit);
 122 void jffs_build_end(struct jffs_fmcontrol *fmc);
 123 void jffs_cleanup_fmcontrol(struct jffs_fmcontrol *fmc);
 124
 125 int jffs_fmalloc(struct jffs_fmcontrol *fmc, __u32 size,
 126                  struct jffs_node *node, struct jffs_fm **result);
 127 int jffs_fmfree(struct jffs_fmcontrol *fmc, struct jffs_fm *fm,
 128                 struct jffs_node *node);
 129
 130 __u32 jffs_free_size1(struct jffs_fmcontrol *fmc);
 131 __u32 jffs_free_size2(struct jffs_fmcontrol *fmc);
 132 void jffs_sync_erase(struct jffs_fmcontrol *fmc, int erased_size);
 133 struct jffs_fm *jffs_cut_node(struct jffs_fmcontrol *fmc, __u32 size);
 134 struct jffs_node *jffs_get_oldest_node(struct jffs_fmcontrol *fmc);
 135 long jffs_erasable_size(struct jffs_fmcontrol *fmc);
 136 struct jffs_fm *jffs_fmalloced(struct jffs_fmcontrol *fmc, __u32 offset,
 137                                __u32 size, struct jffs_node *node);
 138 int jffs_add_node(struct jffs_node *node);
 139 void jffs_fmfree_partly(struct jffs_fmcontrol *fmc, struct jffs_fm *fm,
 140                         __u32 size);
 141
 142 #if CONFIG_JFFS_FS_VERBOSE > 0
 143 void jffs_print_fmcontrol(struct jffs_fmcontrol *fmc);
 144 #endif
 145 #if 0
 146 void jffs_print_node_ref(struct jffs_node_ref *ref);
 147 #endif  /*  0  */
 148
 149 #endif /* __LINUX_JFFS_FM_H__  */