fs/reiser4/plugin/plugin_header.h

   1 /* Copyright 2002, 2003 by Hans Reiser, licensing governed by reiser4/README */
   2
   3 /* plugin header. Data structures required by all plugin types. */
   4
   5 #if !defined(__PLUGIN_HEADER_H__)
   6 #define __PLUGIN_HEADER_H__
   7
   8 /* plugin data-types and constants */
   9
  10 #include "../debug.h"
  11 #include "../dformat.h"
  12
  13 /* The list of Reiser4 interfaces */
  14 typedef enum {
  15         REISER4_FILE_PLUGIN_TYPE,             /* manage VFS objects */
  16         REISER4_DIR_PLUGIN_TYPE,              /* manage directories */
  17         REISER4_ITEM_PLUGIN_TYPE,             /* manage items */
  18         REISER4_NODE_PLUGIN_TYPE,             /* manage formatted nodes */
  19         REISER4_HASH_PLUGIN_TYPE,             /* hash methods */
  20         REISER4_FIBRATION_PLUGIN_TYPE,        /* directory fibrations */
  21         REISER4_FORMATTING_PLUGIN_TYPE,       /* dispatching policy */
  22         REISER4_PERM_PLUGIN_TYPE,             /* stub (vacancy) */
  23         REISER4_SD_EXT_PLUGIN_TYPE,           /* manage stat-data extensions */
  24         REISER4_FORMAT_PLUGIN_TYPE,           /* disk format specifications */
  25         REISER4_JNODE_PLUGIN_TYPE,            /* manage in-memory headers */
  26         REISER4_CIPHER_PLUGIN_TYPE,           /* cipher transform methods */
  27         REISER4_DIGEST_PLUGIN_TYPE,           /* digest transform methods */
  28         REISER4_COMPRESSION_PLUGIN_TYPE,      /* compression methods */
  29         REISER4_COMPRESSION_MODE_PLUGIN_TYPE, /* dispatching policies */
  30         REISER4_CLUSTER_PLUGIN_TYPE,          /* manage logical clusters */
  31         REISER4_PLUGIN_TYPES
  32 } reiser4_plugin_type;
  33
  34 /* Supported plugin groups */
  35 typedef enum {
  36         REISER4_DIRECTORY_FILE,
  37         REISER4_REGULAR_FILE,
  38         REISER4_SYMLINK_FILE,
  39         REISER4_SPECIAL_FILE,
  40 } file_plugin_group;
  41
  42 struct reiser4_plugin_ops;
  43 /* generic plugin operations, supported by each
  44     plugin type. */
  45 typedef struct reiser4_plugin_ops reiser4_plugin_ops;
  46
  47 /* the common part of all plugin instances. */
  48 typedef struct plugin_header {
  49         /* plugin type */
  50         reiser4_plugin_type type_id;
  51         /* id of this plugin */
  52         reiser4_plugin_id id;
  53         /* bitmask of groups the plugin belongs to. */
  54         reiser4_plugin_groups groups;
  55         /* plugin operations */
  56         reiser4_plugin_ops *pops;
  57 /* NIKITA-FIXME-HANS: usage of and access to label and desc is not commented and
  58  * defined. */
  59         /* short label of this plugin */
  60         const char *label;
  61         /* descriptive string.. */
  62         const char *desc;
  63         /* list linkage */
  64         struct list_head linkage;
  65 } plugin_header;
  66
  67 #define plugin_of_group(plug, group) (plug->h.groups & (1 << group))
  68
  69 /* PRIVATE INTERFACES */
  70 /* NIKITA-FIXME-HANS: what is this for and why does it duplicate what is in
  71  * plugin_header? */
  72 /* plugin type representation. */
  73 struct reiser4_plugin_type_data {
  74         /* internal plugin type identifier. Should coincide with
  75            index of this item in plugins[] array. */
  76         reiser4_plugin_type type_id;
  77         /* short symbolic label of this plugin type. Should be no longer
  78            than MAX_PLUGIN_TYPE_LABEL_LEN characters including '\0'. */
  79         const char *label;
  80         /* plugin type description longer than .label */
  81         const char *desc;
  82
  83 /* NIKITA-FIXME-HANS: define built-in */
  84         /* number of built-in plugin instances of this type */
  85         int builtin_num;
  86         /* array of built-in plugins */
  87         void *builtin;
  88         struct list_head plugins_list;
  89         size_t size;
  90 };
  91
  92 extern struct reiser4_plugin_type_data plugins[REISER4_PLUGIN_TYPES];
  93
  94 int is_plugin_type_valid(reiser4_plugin_type type);
  95 int is_plugin_id_valid(reiser4_plugin_type type, reiser4_plugin_id id);
  96
  97 static inline reiser4_plugin *plugin_at(struct reiser4_plugin_type_data *ptype,
  98                                         int i)
  99 {
 100         char *builtin;
 101
 102         builtin = ptype->builtin;
 103         return (reiser4_plugin *) (builtin + i * ptype->size);
 104 }
 105
 106 /* return plugin by its @type_id and @id */
 107 static inline reiser4_plugin *plugin_by_id(reiser4_plugin_type type,
 108                                            reiser4_plugin_id id)
 109 {
 110         assert("nikita-1651", is_plugin_type_valid(type));
 111         assert("nikita-1652", is_plugin_id_valid(type, id));
 112         return plugin_at(&plugins[type], id);
 113 }
 114
 115 extern reiser4_plugin *plugin_by_unsafe_id(reiser4_plugin_type type_id,
 116                                            reiser4_plugin_id id);
 117
 118 /**
 119  * plugin_by_disk_id - get reiser4_plugin
 120  * @type_id: plugin type id
 121  * @did: plugin id in disk format
 122  *
 123  * Returns reiser4_plugin by plugin type id an dplugin_id.
 124  */
 125 static inline reiser4_plugin *plugin_by_disk_id(reiser4_tree * tree UNUSED_ARG,
 126                                                 reiser4_plugin_type type_id,
 127                                                 __le16 *plugin_id)
 128 {
 129         /*
 130          * what we should do properly is to maintain within each file-system a
 131          * dictionary that maps on-disk plugin ids to "universal" ids. This
 132          * dictionary will be resolved on mount time, so that this function
 133          * will perform just one additional array lookup.
 134          */
 135         return plugin_by_unsafe_id(type_id, le16_to_cpu(*plugin_id));
 136 }
 137
 138 /* __PLUGIN_HEADER_H__ */
 139 #endif
 140
 141 /*
 142  * Local variables:
 143  * c-indentation-style: "K&R"
 144  * mode-name: "LC"
 145  * c-basic-offset: 8
 146  * tab-width: 8
 147  * fill-column: 79
 148  * End:
 149  */