1 | /* |
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2 | * vfs.h - Virtual File System definition. |
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3 | * |
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4 | * Author Mohamed Lamine Karaoui (2014,2015) |
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5 | * Alain Greiner (2016,2017,2018) |
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6 | * |
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7 | * Copyright (c) UPMC Sorbonne Universites |
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8 | * |
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9 | * This file is part of ALMOS-MKH. |
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10 | * |
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11 | * ALMOS-MKH is free software; you can redistribute it and/or modify it |
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12 | * under the terms of the GNU General Public License as published by |
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13 | * the Free Software Foundation; version 2.0 of the License. |
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14 | * |
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15 | * ALMOS-MKH is distributed in the hope that it will be useful, but |
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16 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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18 | * General Public License for more details. |
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19 | * |
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20 | * You should have received a copy of the GNU General Public License |
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21 | * along with ALMOS-MKH; if not, write to the Free Software Foundation, |
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22 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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23 | */ |
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24 | |
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25 | #ifndef _VFS_H_ |
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26 | #define _VFS_H_ |
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27 | |
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28 | #include <kernel_config.h> |
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29 | #include <hal_kernel_types.h> |
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30 | #include <hal_atomic.h> |
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31 | #include <remote_rwlock.h> |
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32 | #include <remote_busylock.h> |
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33 | #include <busylock.h> |
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34 | #include <list.h> |
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35 | #include <xlist.h> |
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36 | #include <bits.h> |
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37 | #include <xhtab.h> |
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38 | #include <errno.h> |
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39 | #include <shared_syscalls.h> |
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40 | #include <fatfs.h> |
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41 | #include <ramfs.h> |
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42 | #include <devfs.h> |
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43 | |
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44 | /**** Forward declarations ***/ |
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45 | |
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46 | struct vfs_inode_s; |
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47 | struct vfs_dentry_t; |
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48 | struct vfs_ctx_t; |
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49 | struct vfs_file_ref_s; |
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50 | struct vfs_file_s; |
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51 | |
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52 | struct vfs_inode_op_s; |
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53 | struct vfs_dentry_op_s; |
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54 | struct vfs_file_op_s; |
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55 | struct vfs_ctx_op_s; |
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56 | |
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57 | struct vfs_lookup_cmd_s; |
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58 | struct vfs_lookup_rsp_s; |
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59 | |
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60 | struct mapper_s; |
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61 | struct process_s; |
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62 | struct device_s; |
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63 | struct vseg_s; |
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64 | struct page_s; |
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65 | |
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66 | |
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67 | /****************************************************************************************** |
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68 | * These flags are used to define the working mode of the vfs_lookup() function. |
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69 | *****************************************************************************************/ |
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70 | |
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71 | #define VFS_LOOKUP_DIR 0x01 /* the searched inode must be a directory */ |
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72 | #define VFS_LOOKUP_OPEN 0x02 /* the search is for an open/opendir */ |
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73 | #define VFS_LOOKUP_PARENT 0x04 /* return the parent inode (not the inode itself) */ |
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74 | #define VFS_LOOKUP_CREATE 0x10 /* file must be created if missing */ |
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75 | #define VFS_LOOKUP_EXCL 0x20 /* file cannot previously exist */ |
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76 | |
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77 | /****************************************************************************************** |
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78 | * This structure defines a VFS context, that contains informations common to all inodes |
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79 | * and dentries for a given file system. As it is declared as a global variable in the |
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80 | * kdata segment (fs_context[] array), it is replicated in all clusters. |
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81 | * The <extend> field is a pointer on the FS specific context extension. |
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82 | * This extension is dynamically allocated by kernel_init in all clusters. |
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83 | * In each cluster, both this VFS context and the FS specific context are handled as |
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84 | * private by the local OS intance. |
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85 | *****************************************************************************************/ |
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86 | |
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87 | typedef enum |
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88 | { |
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89 | FS_TYPE_DEVFS = 0, |
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90 | FS_TYPE_FATFS = 1, |
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91 | FS_TYPE_RAMFS = 2, |
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92 | |
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93 | FS_TYPES_NR = 3, |
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94 | } |
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95 | vfs_fs_type_t; |
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96 | |
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97 | typedef enum |
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98 | { |
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99 | CTX_ATTR_READ_ONLY = 0x01, /*! write access prohibited */ |
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100 | CTX_ATTR_SYNC = 0x10, /*! synchronise FS on each write */ |
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101 | } |
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102 | vfs_ctx_attr_t; |
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103 | |
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104 | typedef struct vfs_ctx_s |
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105 | { |
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106 | vfs_fs_type_t type; /*! File System type */ |
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107 | uint32_t attr; /*! global attributes for all files in FS */ |
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108 | uint32_t total_clusters; /*! total number of clusters on device */ |
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109 | uint32_t cluster_size; /*! cluster size on device (bytes) */ |
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110 | xptr_t vfs_root_xp; /*! extended pointer on VFS root inode */ |
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111 | busylock_t lock; /*! lock protecting inum allocator */ |
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112 | uint32_t bitmap[BITMAP_SIZE(CONFIG_VFS_MAX_INODES)]; /* inum allocator */ |
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113 | void * extend; /*! FS specific context extension */ |
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114 | } |
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115 | vfs_ctx_t; |
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116 | |
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117 | /****************************************************************************************** |
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118 | * This structure define a VFS inode. |
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119 | * An inode has several children dentries (if it is a directory), an can have several |
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120 | * parents dentries (if it hass several aliases links): |
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121 | * - The "parents" field is the root of the xlist of parents dentries, and the "links" |
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122 | * fiels define the number of aliases parent dentries. only a FILE inode can have |
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123 | * several parents (no hard links for directories). |
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124 | * - The "children" field is an embedded xhtab containing pointers on all local children |
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125 | * dentries. This set of children is empty for a FILE inode. |
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126 | * Synchronisation: |
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127 | * - the main_lock (remote_rwlock) is used during the inode tree traversal, |
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128 | * or for inode modification (add/remove children in xhtab). |
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129 | * - the size_lock (remote_rwlock) is used during read/write accesses to the size |
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130 | * field in the mapper. |
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131 | * - access to the data stored in the associated mapper use the mapper remote_rwlock |
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132 | * protecting radix tree traversal and modifications. |
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133 | *****************************************************************************************/ |
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134 | |
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135 | /* this enum define the VFS inode types values */ |
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136 | /* WARNING : this enum must be kept consistent with macros in <shared_stat.h> file */ |
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137 | |
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138 | typedef enum |
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139 | { |
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140 | INODE_TYPE_FILE = 0, /*! regular file */ |
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141 | INODE_TYPE_DIR = 1, /*! directory */ |
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142 | INODE_TYPE_FIFO = 2, /*! POSIX named pipe */ |
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143 | INODE_TYPE_PIPE = 3, /*! POSIX anonymous pipe */ |
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144 | INODE_TYPE_SOCK = 4, /*! POSIX socket */ |
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145 | INODE_TYPE_DEV = 5, /*! character device */ |
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146 | INODE_TYPE_SYML = 6, /*! symbolic link */ |
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147 | } |
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148 | vfs_inode_type_t; |
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149 | |
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150 | /* this enum define the VFS inode attributes values */ |
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151 | |
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152 | typedef enum |
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153 | { |
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154 | INODE_ATTR_DIRTY = 0x01, /* modified versus the value on device */ |
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155 | INODE_ATTR_INLOAD = 0x04, /* loading from device in progress */ |
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156 | INODE_ATTR_NEW = 0x08, /* not saved on device yet */ |
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157 | } |
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158 | vfs_inode_attr_t; |
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159 | |
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160 | typedef struct vfs_inode_s |
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161 | { |
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162 | struct vfs_ctx_s * ctx; /*! local pointer on FS context */ |
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163 | uint32_t inum; /*! inode identifier (unique in file system) */ |
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164 | uint32_t attr; /*! inode attributes (see above) */ |
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165 | vfs_inode_type_t type; /*! inode type (see above) */ |
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166 | uint32_t size; /*! number of bytes */ |
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167 | uint32_t uid; /*! user owner identifier */ |
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168 | uint32_t gid; /*! group owner identifier */ |
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169 | uint32_t rights; /*! access rights */ |
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170 | xlist_entry_t parents; /*! root of list of parents dentries */ |
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171 | uint32_t links; /*! number of parent dentries (hard links) */ |
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172 | xhtab_t children; /*! embedded xhtab of children dentries */ |
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173 | remote_rwlock_t size_lock; /*! protect read/write to size */ |
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174 | remote_rwlock_t main_lock; /*! protect inode tree traversal and modifs */ |
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175 | // list_entry_t list; /*! member of set of inodes in same cluster */ |
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176 | // list_entry_t wait_root; /*! root of threads waiting on this inode */ |
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177 | struct mapper_s * mapper; /*! associated file cache */ |
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178 | void * extend; /*! fs_type_specific inode extension */ |
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179 | } |
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180 | vfs_inode_t; |
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181 | |
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182 | /* This define the masks for the inode <rights> field */ |
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183 | |
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184 | #define VFS_ISUID 0x0004000 |
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185 | #define VFS_ISGID 0x0002000 |
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186 | define VFS_ISVTX 0x0001000 |
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187 | |
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188 | #define VFS_IRWXU 0x0000700 |
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189 | #define VFS_IRUSR 0x0000400 |
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190 | #define VFS_IWUSR 0x0000200 |
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191 | #define VFS_IXUSR 0x0000100 |
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192 | |
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193 | #define VFS_IRWXG 0x0000070 |
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194 | #define VFS_IRGRP 0x0000040 |
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195 | #define VFS_IWGRP 0x0000020 |
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196 | #define VFS_IXGRP 0x0000010 |
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197 | |
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198 | #define VFS_IRWXO 0x0000007 |
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199 | #define VFS_IROTH 0x0000004 |
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200 | #define VFS_IWOTH 0x0000002 |
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201 | #define VFS_IXOTH 0x0000001 |
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202 | |
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203 | /****************************************************************************************** |
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204 | * This structure defines a directory entry. |
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205 | * A dentry contains the name of a remote file/dir, an extended pointer on the |
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206 | * inode representing this file/dir, a local pointer on the inode representing |
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207 | * the parent directory. |
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208 | * A dentry can be member of the set of children of a given directory inode (xhtab). |
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209 | * A dentry can be member of the set of parents of a given inode (xlist). |
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210 | *****************************************************************************************/ |
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211 | |
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212 | typedef struct vfs_dentry_s |
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213 | { |
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214 | struct vfs_ctx_s * ctx; /*! local pointer on FS context */ |
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215 | char name[CONFIG_VFS_MAX_NAME_LENGTH]; |
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216 | uint32_t length; /*! name length (bytes) */ |
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217 | struct vfs_inode_s * parent; /*! local pointer on parent inode */ |
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218 | xptr_t child_xp; /*! extended pointer on child inode */ |
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219 | xlist_entry_t children; /*! member of set of children dentries */ |
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220 | xlist_entry_t parents; /*! member of set of parent dentries */ |
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221 | void * extend; /*! FS specific extension */ |
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222 | } |
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223 | vfs_dentry_t; |
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224 | |
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225 | /****************************************************************************************** |
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226 | * This file structure describes an open file/directory for a given process. |
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227 | * It is not replicated, and is dynamically allocated in the cluster that contains |
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228 | * the inode, when a thread makes an open() or opendir() system call. |
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229 | * It cannot exist a file structure without an inode structure in same cluster. |
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230 | * As the fd_array (containing extended pointers on the open file descriptors) |
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231 | * is replicated in all process descriptors, we need a references counter. |
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232 | *****************************************************************************************/ |
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233 | |
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234 | typedef enum |
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235 | { |
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236 | FD_ATTR_READ_ENABLE = 0x01, /*! read access possible */ |
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237 | FD_ATTR_WRITE_ENABLE = 0x02, /*! write access possible */ |
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238 | FD_ATTR_APPEND = 0x04, /*! append on each write */ |
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239 | FD_ATTR_CLOSE_EXEC = 0x08, /*! close file on exec */ |
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240 | FD_ATTR_SYNC = 0x10, /*! synchronise FS on each write */ |
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241 | FD_ATTR_IS_DIR = 0x20, /*! this is a directory */ |
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242 | } |
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243 | vfs_file_attr_t; |
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244 | |
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245 | typedef struct vfs_file_s |
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246 | { |
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247 | struct vfs_ctx_s * ctx; /*! local pointer on FS context. */ |
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248 | uint32_t gc; /*! generation counter */ |
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249 | vfs_file_attr_t attr; /*! file attributes bit vector (see above) */ |
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250 | vfs_inode_type_t type; /*! same type as inode */ |
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251 | uint32_t offset; /*! seek position in file */ |
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252 | uint32_t refcount; /*! all pointers on this file descriptor */ |
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253 | remote_rwlock_t lock; /*! protect offset modifications */ |
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254 | struct mapper_s * mapper; /*! associated file cache */ |
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255 | struct vfs_inode_s * inode; /*! local pointer on associated inode */ |
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256 | void * extend; /*! FS specific extension */ |
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257 | } |
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258 | vfs_file_t; |
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259 | |
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260 | |
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261 | /****************************************************************************************** |
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262 | * These functions access / modify a VFS context. |
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263 | *****************************************************************************************/ |
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264 | |
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265 | /****************************************************************************************** |
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266 | * This function initialise a (statically allocated) VFS context in local cluster. |
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267 | ****************************************************************************************** |
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268 | * @ fs_type : file system type. |
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269 | * @ attr : global attributes (for all files in FS. |
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270 | * @ total_clusters : total number of clusters on device. |
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271 | * @ cluster_size : cluster size on device (bytes). |
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272 | * @ vfs_root_xp : extended pointer on VFS root inode. |
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273 | * @ extend : fs_type_specific extension. |
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274 | *****************************************************************************************/ |
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275 | void vfs_ctx_init( vfs_fs_type_t type, |
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276 | uint32_t attr, |
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277 | uint32_t total_clusters, |
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278 | uint32_t cluster_size, |
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279 | xptr_t vfs_root_xp, |
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280 | void * extend ); |
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281 | |
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282 | /****************************************************************************************** |
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283 | * This function allocates an inode identifier from the local cluster inum allocator. |
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284 | * The inum respects a fixed format: |
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285 | * - the 16 MSB bits contain the cluster identifier : cxy |
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286 | * - the 16 LSB bits contains the local inode identifier : lid |
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287 | ****************************************************************************************** |
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288 | * @ ctx : local pointer on file system context. |
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289 | * @ inum : [ou] buffer for allocated inode identifier. |
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290 | * @ return 0 if success / return non-zero if error. |
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291 | *****************************************************************************************/ |
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292 | error_t vfs_ctx_inum_alloc( vfs_ctx_t * ctx, |
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293 | uint32_t * inum ); |
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294 | |
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295 | /****************************************************************************************** |
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296 | * This function release an inode identifier. |
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297 | ****************************************************************************************** |
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298 | * @ ctx : local pointer on file system context. |
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299 | * @ inum : released inode identifier. |
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300 | *****************************************************************************************/ |
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301 | void vfs_ctx_inum_release( vfs_ctx_t * ctx, |
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302 | uint32_t inum ); |
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303 | |
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304 | |
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305 | |
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306 | /****************************************************************************************** |
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307 | * These low-level functions access / modify a VFS inode descriptor |
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308 | *****************************************************************************************/ |
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309 | |
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310 | /****************************************************************************************** |
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311 | * This function returns a printable string for the inode type. |
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312 | *****************************************************************************************/ |
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313 | const char * vfs_inode_type_str( vfs_inode_type_t type ); |
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314 | |
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315 | /****************************************************************************************** |
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316 | * This function allocates memory from local cluster for an inode descriptor and the |
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317 | * associated mapper. It initialise these descriptors from arguments values. |
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318 | * If the client thread is not running in the cluster containing this inode, |
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319 | * it must use the rpc_vfs_inode_create_client() function. |
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320 | ****************************************************************************************** |
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321 | * @ fs_type : file system type. |
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322 | * @ inode_type : inode type. |
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323 | * @ attr : inode attributes. |
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324 | * @ rights : inode access rights. |
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325 | * @ uid : user owner ID. |
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326 | * @ gid : group owner ID. |
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327 | * @ inode_xp : [out] buffer for extended pointer on created inode. |
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328 | * @ return 0 if success / return ENOMEM or EINVAL if error. |
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329 | *****************************************************************************************/ |
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330 | error_t vfs_inode_create( vfs_fs_type_t fs_type, |
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331 | vfs_inode_type_t inode_type, |
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332 | uint32_t attr, |
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333 | uint32_t rights, |
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334 | uid_t uid, |
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335 | gid_t gid, |
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336 | xptr_t * inode_xp ); |
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337 | |
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338 | /****************************************************************************************** |
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339 | * This function releases memory allocated to an inode descriptor, including |
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340 | * all memory allocated to the mapper (both mapper descriptor and radix tree). |
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341 | * The mapper should not contain any dirty page (should be synchronized before deletion). |
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342 | * It must be executed by a thread running in the cluster containing the inode. |
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343 | * Use the rpc_vfs_inode_destroy_client() function if required. |
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344 | ****************************************************************************************** |
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345 | * @ inode : local pointer on inode descriptor. |
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346 | *****************************************************************************************/ |
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347 | void vfs_inode_destroy( vfs_inode_t * inode ); |
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348 | |
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349 | /****************************************************************************************** |
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350 | * This function returns the <size> of a file/dir from a remote inode, |
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351 | * taking the remote_rwlock protecting <size> in READ_MODE. |
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352 | ***************************************************************************************** |
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353 | * @ inode_xp : extended pointer on the remote inode. |
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354 | * @ return the current size. |
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355 | *****************************************************************************************/ |
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356 | uint32_t vfs_inode_get_size( xptr_t inode_xp ); |
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357 | |
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358 | /****************************************************************************************** |
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359 | * This function set the <size> of a file/dir to a remote inode, |
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360 | * taking the remote_rwlock protecting <size> in WRITE_MODE. |
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361 | ***************************************************************************************** |
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362 | * @ inode_xp : extended pointer on the remote inode. |
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363 | * @ size : value to be written. |
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364 | *****************************************************************************************/ |
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365 | void vfs_inode_set_size( xptr_t inode_xp, |
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366 | uint32_t size ); |
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367 | |
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368 | /****************************************************************************************** |
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369 | * This function takes the main lock of a remote inode. |
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370 | * This lock protect all inode fields, including the children dentries. |
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371 | ***************************************************************************************** |
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372 | * @ inode_xp : extended pointer on the remote inode. |
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373 | *****************************************************************************************/ |
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374 | void vfs_inode_lock( xptr_t inode_xp ); |
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375 | |
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376 | /****************************************************************************************** |
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377 | * This function releases the main lock of a remote inode. |
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378 | * This lock protect all inode fiels, including the children dentries. |
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379 | ***************************************************************************************** |
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380 | * @ inode_xp : extended pointer on the remote inode. |
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381 | *****************************************************************************************/ |
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382 | void vfs_inode_unlock( xptr_t inode_xp ); |
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383 | |
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384 | /****************************************************************************************** |
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385 | * This debug function copies the name of a remote inode identified by the <inode_xp> |
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386 | * argument to a local buffer identified by the <name> argument. |
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387 | * The local buffer size must be at least CONFIG_VFS_MAX_NAME_LENGTH. |
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388 | ***************************************************************************************** |
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389 | * @ inode_xp : extended pointer on the remote inode. |
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390 | * @ name : local buffer pointer. |
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391 | *****************************************************************************************/ |
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392 | void vfs_inode_get_name( xptr_t inode_xp, |
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393 | char * name ); |
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394 | |
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395 | /****************************************************************************************** |
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396 | * This function accesses successively all pages of a file identified by the <inode>, |
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397 | * argument, to force misses, and load all pages into mapper. |
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398 | * The target inode can be a directory or a file, but this function is mainly used |
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399 | * to prefetch a complete directory to the mapper. |
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400 | * It must be executed by a thread running in the cluster containing the inode. |
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401 | * This function does NOT take any lock. |
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402 | ****************************************************************************************** |
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403 | * @ inode : local pointer on inode. |
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404 | * @ return 0 if success / return -1 if device access failure. |
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405 | *****************************************************************************************/ |
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406 | error_t vfs_inode_load_all_pages( vfs_inode_t * inode ); |
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407 | |
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408 | |
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409 | /****************************************************************************************** |
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410 | * These low-level functions access / modify a VFS dentry descriptor |
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411 | *****************************************************************************************/ |
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412 | |
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413 | /****************************************************************************************** |
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414 | * This function allocates memory from local cluster for a dentry descriptor, |
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415 | * initialises it from arguments values, and returns the extended pointer on dentry. |
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416 | * If the client thread is not running in the target cluster for this inode, |
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417 | * it must use the rpc_dentry_create_client() function. |
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418 | ****************************************************************************************** |
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419 | * @ fs_type : file system type. |
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420 | * @ name : directory entry file/dir name. |
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421 | * @ dentry_xp : [out] buffer for extended pointer on created dentry. |
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422 | * @ return 0 if success / return ENOMEM or EINVAL if error. |
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423 | *****************************************************************************************/ |
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424 | error_t vfs_dentry_create( vfs_fs_type_t fs_type, |
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425 | char * name, |
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426 | xptr_t * dentry_xp ); |
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427 | |
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428 | /****************************************************************************************** |
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429 | * This function removes the dentry from the parent inode xhtab, and releases the memory |
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430 | * allocated to the dentry descriptor. |
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431 | * It must be executed by a thread running in the cluster containing the dentry. |
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432 | * Use the rpc_vfs_dentry_destroy_client() function if required. |
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433 | ****************************************************************************************** |
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434 | * @ dentry : local pointer on dentry descriptor. |
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435 | *****************************************************************************************/ |
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436 | void vfs_dentry_destroy( vfs_dentry_t * dentry ); |
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437 | |
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438 | |
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439 | /****************************************************************************************** |
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440 | * These low-level functions access / modify a VFS file descriptor |
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441 | *****************************************************************************************/ |
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442 | |
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443 | /****************************************************************************************** |
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444 | * This function allocates memory and initializes a new local file descriptor. |
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445 | * It must be executed in the cluster containing the inode. |
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446 | * If the client thread is not running in the owner cluster, it must use the |
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447 | * rpc_vfs_file_create_client() function. |
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448 | ****************************************************************************************** |
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449 | * @ inode : local pointer on associated inode. |
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450 | * @ attr : file descriptor attributes. |
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451 | * @ file_xp : [out] buffer for extended pointer on created file descriptor. |
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452 | * @ return 0 if success / return ENOMEM if error. |
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453 | *****************************************************************************************/ |
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454 | error_t vfs_file_create( vfs_inode_t * inode, |
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455 | uint32_t attr, |
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456 | xptr_t * file_xp ); |
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457 | |
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458 | /****************************************************************************************** |
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459 | * This function releases memory allocated to a local file descriptor. |
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460 | * It must be executed by a thread running in the cluster containing the inode, |
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461 | * and the file refcount must be zero. |
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462 | * If the client thread is not running in the owner cluster, it must use the |
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463 | * rpc_vfs_file_destroy_client() function. |
---|
464 | ****************************************************************************************** |
---|
465 | * @ file : local pointer on file descriptor. |
---|
466 | *****************************************************************************************/ |
---|
467 | void vfs_file_destroy( vfs_file_t * file ); |
---|
468 | |
---|
469 | /****************************************************************************************** |
---|
470 | * These functions increment (resp. decrement) the count field in a remote file |
---|
471 | * descriptor, using a remote_atomic access. |
---|
472 | *****************************************************************************************/ |
---|
473 | void vfs_file_count_up ( xptr_t file_xp ); |
---|
474 | void vfs_file_count_down( xptr_t file_xp ); |
---|
475 | |
---|
476 | |
---|
477 | |
---|
478 | /****************************************************************************************** |
---|
479 | * These functions access / modify the distributed VFS Inode Tree |
---|
480 | *****************************************************************************************/ |
---|
481 | |
---|
482 | /****************************************************************************************** |
---|
483 | * This function returns in a kernel <buffer> allocated by the caller function, |
---|
484 | * the pathname of a file/dir identified by the <inode_xp> argument. |
---|
485 | * It traverse the Inode Tree from the target node to the root. |
---|
486 | * It can be called by any thread running in any cluster. |
---|
487 | * As this buffer if filled in "reverse order" (i.e. from the target inode to the root), |
---|
488 | * the pathname is stored in the higher part of the buffer. |
---|
489 | * A pointer on the first character of the pathname is returned in <first> buffer. |
---|
490 | * |
---|
491 | * WARNING : This function takes & releases the remote_rwlock protecting the Inode Tree. |
---|
492 | ****************************************************************************************** |
---|
493 | * @ inode_xp : [in] extended pointer on target inode descriptor. |
---|
494 | * @ buffer : [in] kernel buffer for pathname (allocated by caller). |
---|
495 | * @ first : [out] pointer on first character in buffer. |
---|
496 | * @ max_size : [in] max number of characters in buffer. |
---|
497 | * @ return 0 if success / return EINVAL if buffer too small. |
---|
498 | *****************************************************************************************/ |
---|
499 | error_t vfs_get_path( xptr_t inode_xp, |
---|
500 | char * buffer, |
---|
501 | char ** first, |
---|
502 | uint32_t max_size ); |
---|
503 | |
---|
504 | /****************************************************************************************** |
---|
505 | * This function traverses the the Inode Tree, from inode identified by the <root_xp> |
---|
506 | * argument, and returns in <inode_xp> the inode identified by the < pathname> argument. |
---|
507 | * It can be called by a thread running in any cluster. |
---|
508 | * It supports the following flags that define the lookup modes : |
---|
509 | * - VFS_LOOKUP_DIR : the searched inode must be a directory |
---|
510 | * - VFS_LOOKUP_OPEN : the search is for an open/opendir |
---|
511 | * - VFS_LOOKUP_PARENT : return the parent inode (not the inode itself) |
---|
512 | * - VFS_LOOKUP_CREATE : file/directory must be created if missing on IOC |
---|
513 | * - VFS_LOOKUP_EXCL : file cannot previously exist |
---|
514 | * As the inode Tree is a cache, the search policy is the following : |
---|
515 | * - If a given directory name in the path is not found in the inode tree, it try to load |
---|
516 | * the missing dentry/inode couple, from informations found in the parent directory. |
---|
517 | * - If this directory entry does not exist on IOC, it returns an error. |
---|
518 | * - If the the file identified by the pathname does not exist on IOC but the |
---|
519 | * flag CREATE is set, the inode is created. It returns an error otherwise. |
---|
520 | * - If the the file identified by the pathname exist on device, but both flags EXCL |
---|
521 | * and CREATE are set, an error is returned. |
---|
522 | * - If the PARENT flag is set, it returns in <inode_xp> an extended pointer on the parent |
---|
523 | * inode, and copies in <last_name> buffer a string containing the last name in path. |
---|
524 | * |
---|
525 | * WARNING : The remote_rwlock protecting the Inode Tree must be taken by the caller. |
---|
526 | * |
---|
527 | * TODO the access rights are not checked yet. |
---|
528 | ****************************************************************************************** |
---|
529 | * @ root_xp : [in] extended pointer on root inode (can be root of a subtree). |
---|
530 | * @ pathname : [in] path (can be relative or absolute). |
---|
531 | * @ lookup_mode : [in] flags defining the searching mode. |
---|
532 | * @ inode_xp : [out] buffer for extended pointer on searched inode. |
---|
533 | * @ last_name : [out] pointer on buffer for last name in path. |
---|
534 | * @ return 0 if success / ENOENT if inode not found , EACCES if permisson denied, |
---|
535 | *****************************************************************************************/ |
---|
536 | error_t vfs_lookup( xptr_t root_xp, |
---|
537 | char * pathname, |
---|
538 | uint32_t lookup_mode, |
---|
539 | xptr_t * inode_xp, |
---|
540 | char * last_name ); |
---|
541 | |
---|
542 | /****************************************************************************************** |
---|
543 | * This function creates a new couple dentry/inode, and insert it in the Inode-Tree. |
---|
544 | * Only the distributed Inode Tree is modified: it does NOT modify the parent mapper, |
---|
545 | * and does NOT update the FS on IOC device. |
---|
546 | * It can be executed by any thread running in any cluster (can be different from both |
---|
547 | * the child cluster and the parent cluster). |
---|
548 | * |
---|
549 | * [Implementation] |
---|
550 | * As there are cross-references between the inode and the associated dentry, this |
---|
551 | * function implement a three steps scenario : |
---|
552 | * 1) The dentry descriptor is created in the cluster containing the existing <parent_xp> |
---|
553 | * inode, and is only partially initialized : "fs_type", "name", "parent_xp" fields. |
---|
554 | * 2) The inode and its associated mapper are created in cluster identified by <child_cxy>, |
---|
555 | * and initialised. The new inode and the parent inode can have different FS types. |
---|
556 | * 3) The "child_xp" field in dentry (pointing on the created inode) is updated, |
---|
557 | * and the refcount is incremented for both the inode and the dentry. |
---|
558 | ****************************************************************************************** |
---|
559 | * @ child_inode_cxy : [in] target cluster for child inode. |
---|
560 | * @ child_inode_type : [in] child inode type |
---|
561 | * @ fs_type : [in] child inode FS type. |
---|
562 | * @ parent_inode_xp : [in] extended pointer on parent inode. |
---|
563 | * @ name : [in] new directory entry name. |
---|
564 | * @ dentry_xp : [out] buffer for extended pointer on dentry |
---|
565 | * @ child_inode_xp : [out] buffer for extended pointer on child inode. |
---|
566 | * @ return 0 if success / -1 if dentry or inode cannot be created. |
---|
567 | *****************************************************************************************/ |
---|
568 | error_t vfs_add_child_in_parent( cxy_t child_inode_cxy, |
---|
569 | vfs_inode_type_t child_inode_type, |
---|
570 | vfs_fs_type_t fs_type, |
---|
571 | xptr_t parent_inode_xp, |
---|
572 | char * name, |
---|
573 | xptr_t * dentry_xp, |
---|
574 | xptr_t * child_inode_xp ); |
---|
575 | |
---|
576 | /****************************************************************************************** |
---|
577 | * This function removes a remote dentry from the Inode-Tree. |
---|
578 | * - It removes the dentry from the parent inode xhtab ("children" field), and from the |
---|
579 | * child inode xlist ("parents" field). |
---|
580 | * - It releases the memory allocated to the dentry descriptor. |
---|
581 | * - If the number of parents of the child inode is one, it also releases the memory |
---|
582 | * allocated to the child inode. |
---|
583 | * Only the Inode Tree is modified: it does NOT modify the parent mapper, |
---|
584 | * and does NOT update the FS on IOC device. |
---|
585 | * It can be executed by any thread running in any cluster (can be different from both |
---|
586 | * the inode cluster and the dentry cluster). |
---|
587 | ****************************************************************************************** |
---|
588 | * @ dentry_xp : extended pointer on removed dentry. |
---|
589 | *****************************************************************************************/ |
---|
590 | void vfs_remove_child_from_parent( xptr_t dentry_xp ); |
---|
591 | |
---|
592 | /****************************************************************************************** |
---|
593 | * This function is called by the vfs_lookup() function when a new dentry/inode must |
---|
594 | * be created from scratch and introduced in both the Inode Tree and the IOC device. |
---|
595 | * The dentry and inode descriptors have been created by the caller: |
---|
596 | * - It allocates one cluster from the relevant FS, and updates the File Allocation |
---|
597 | * Table (both the FAT mapper, and the IOC device). |
---|
598 | * - It set the "size", and "extend" fields in child inode descriptor. |
---|
599 | * - It updates the parent directory to introduce the new child in the parent directory |
---|
600 | * inode descriptor (radix tree), in theparent inode mapper, and on IOC device. |
---|
601 | * - It set the "extend" field in dentry descriptor. |
---|
602 | * It can be called by a thread running in any cluster. |
---|
603 | ****************************************************************************************** |
---|
604 | * @ parent_xp : extended pointer on parent inode descriptor. |
---|
605 | * @ dentry_xp : extended pointer on new dentry descriptor. |
---|
606 | * @ child_xp : extended pointer on child inode descriptor. |
---|
607 | * @ return 0 if success / -1 if failure. |
---|
608 | *****************************************************************************************/ |
---|
609 | error_t vfs_new_child_init( xptr_t parent_xp, |
---|
610 | xptr_t dentry_xp, |
---|
611 | xptr_t child_xp ); |
---|
612 | |
---|
613 | /****************************************************************************************** |
---|
614 | * This recursive function diplays a complete inode/dentry sub-tree. |
---|
615 | * Any inode can be selected as the sub-tree root. |
---|
616 | * TODO this function is not protected against a concurrent inode/dentry removal... |
---|
617 | ****************************************************************************************** |
---|
618 | * @ inode_xp : extended pointer on sub-tree root inode. |
---|
619 | *****************************************************************************************/ |
---|
620 | void vfs_display( xptr_t inode_xp ); |
---|
621 | |
---|
622 | /****************************************************************************************** |
---|
623 | * This function mount a given file system type for a given process |
---|
624 | * TODO non implemented yet [AG]. |
---|
625 | *****************************************************************************************/ |
---|
626 | error_t vfs_mount_fs_root( struct device_s * device, |
---|
627 | uint32_t fs_type, |
---|
628 | struct process_s * process ); |
---|
629 | |
---|
630 | |
---|
631 | |
---|
632 | /****************************************************************************************** |
---|
633 | * These functions define the VFS "syscalls" API (user commands) |
---|
634 | *****************************************************************************************/ |
---|
635 | |
---|
636 | /****************************************************************************************** |
---|
637 | * This function moves <size> bytes between a remote file mapper, identified by the |
---|
638 | * <file_xp> argument, and a - possibly distributed - user space <buffer>, taken into |
---|
639 | * account the offset in <file_xp>. The transfer direction is defined by <to_buffer>. |
---|
640 | * It is called by the sys_read() and sys_write() functions. |
---|
641 | ****************************************************************************************** |
---|
642 | * @ to_buffer : mapper -> buffer if true / buffer -> mapper if false. |
---|
643 | * @ file_xp : extended pointer on the remote file descriptor. |
---|
644 | * @ buffer : user space pointer on buffer (can be physically distributed). |
---|
645 | * @ size : requested number of bytes from offset. |
---|
646 | * @ returns number of bytes actually moved if success / -1 if error. |
---|
647 | *****************************************************************************************/ |
---|
648 | int vfs_user_move( bool_t to_buffer, |
---|
649 | xptr_t file_xp, |
---|
650 | void * buffer, |
---|
651 | uint32_t size ); |
---|
652 | |
---|
653 | /****************************************************************************************** |
---|
654 | * This function moves <size> bytes between a remote file mapper, identified by the |
---|
655 | * <file_xp> argument, and a - possibly remote - kernel <buffer_xp>, taken into |
---|
656 | * account the offset in <file_xp>. The transfer direction is defined by <to_buffer>. |
---|
657 | * It is called by the elf_load_process() function. |
---|
658 | ****************************************************************************************** |
---|
659 | * @ to_buffer : mapper -> buffer if true / buffer -> mapper if false. |
---|
660 | * @ file_xp : extended pointer on the remote file descriptor. |
---|
661 | * @ buffer_xp : user space pointer on buffer (can be physically distributed). |
---|
662 | * @ size : requested number of bytes from offset. |
---|
663 | * @ returns 0 if success / -1 if error. |
---|
664 | *****************************************************************************************/ |
---|
665 | error_t vfs_kernel_move( bool_t to_buffer, |
---|
666 | xptr_t file_xp, |
---|
667 | xptr_t buffer_xp, |
---|
668 | uint32_t size ); |
---|
669 | |
---|
670 | /****************************************************************************************** |
---|
671 | * This function allocates a vfs_file_t structure in the cluster containing the inode |
---|
672 | * identified by the <root_xp> & <path> arguments. |
---|
673 | * It initializes it, register it in the reference process fd_array identified by the |
---|
674 | * <process_xp> argument, and returns both the extended pointer on the file descriptor, |
---|
675 | * and the allocated index in the <file_xp> and <file_id> buffers. |
---|
676 | * The pathname can be relative to current directory or absolute. |
---|
677 | * If the inode does not exist in the inode cache, it try to find the file on the IOC |
---|
678 | * device, and creates an inode on a pseudo randomly selected cluster if found. |
---|
679 | * It the requested file does not exist on device, it creates a new inode if the |
---|
680 | * O_CREAT flag is set, and return an error otherwise. |
---|
681 | * |
---|
682 | * WARNING : this function takes & releases the remote_rwlock protecting the Inode Tree. |
---|
683 | ****************************************************************************************** |
---|
684 | * @ root_xp : extended pointer on path root inode. |
---|
685 | * @ path : file pathname (absolute or relative to current directory). |
---|
686 | * @ process_xp : extended pointer on client reference process. |
---|
687 | * @ flags : defined in vfs_file_t structure. |
---|
688 | * @ mode : access rights (as defined by chmod). |
---|
689 | * @ file_xp : [out] buffer for extended pointer on created remote file descriptor. |
---|
690 | * @ file_id : [out] buffer for created file descriptor index in reference fd_array. |
---|
691 | * @ return 0 if success / return non-zero if error. |
---|
692 | *****************************************************************************************/ |
---|
693 | error_t vfs_open( xptr_t root_xp, |
---|
694 | char * path, |
---|
695 | xptr_t process_xp, |
---|
696 | uint32_t flags, |
---|
697 | uint32_t mode, |
---|
698 | xptr_t * file_xp, |
---|
699 | uint32_t * file_id ); |
---|
700 | |
---|
701 | /****************************************************************************************** |
---|
702 | * This function set a new value in the offset of the open file descriptor <file_xp>. |
---|
703 | * This value depends on the <whence> argument: |
---|
704 | * - if VFS_SEEK_SET, new value is <offset> |
---|
705 | * - if VFS_SEEK_CUR, new value is current_offset + <offset> |
---|
706 | * - if VFS_SEEK_END, new value is file_size + <offset> |
---|
707 | ****************************************************************************************** |
---|
708 | * @ file_xp : extended pointer on the remote open file descriptor. |
---|
709 | * @ offset : local pointer on source kernel buffer. |
---|
710 | * @ whence : VFS_SEEK_SET / VFS_SEEK_CUR / VFS_SEEK_END. |
---|
711 | * @ new_offset : [out] buffer for new offset value. |
---|
712 | * @ returns 0 if success / -1 if error. |
---|
713 | *****************************************************************************************/ |
---|
714 | error_t vfs_lseek( xptr_t file_xp, |
---|
715 | uint32_t offset, |
---|
716 | uint32_t whence, |
---|
717 | uint32_t * new_offset ); |
---|
718 | |
---|
719 | /****************************************************************************************** |
---|
720 | * This function close the - non-replicated - file descriptor identified by the <file_xp> |
---|
721 | * and <file_id> arguments. |
---|
722 | * 1) All entries in the fd_array copies are directly reset by the calling thread, |
---|
723 | * using remote accesses. |
---|
724 | * 2) The memory allocated to file descriptor in cluster containing the inode is released. |
---|
725 | * It requires a RPC if cluster containing the file descriptor is remote. |
---|
726 | ****************************************************************************************** |
---|
727 | * @ file_xp : extended pointer on the file descriptor in owner cluster. |
---|
728 | * @ file_id : file descriptor index in fd_array. |
---|
729 | * @ returns 0 if success / -1 if error. |
---|
730 | *****************************************************************************************/ |
---|
731 | error_t vfs_close( xptr_t file_xp, |
---|
732 | uint32_t file_id ); |
---|
733 | |
---|
734 | /****************************************************************************************** |
---|
735 | * This function is called by the kernel to create in the file system a new directory |
---|
736 | * identified by the <root_xp> & <path> arguments, with the access permission defined |
---|
737 | * by the <rights> argument. All nodes in the path - but the last - must exist. |
---|
738 | * |
---|
739 | * WARNING : this function takes & releases the remote_rwlock protecting the Inode Tree. |
---|
740 | ****************************************************************************************** |
---|
741 | * @ root_xp : extended pointer on path root inode (any inode in Inode Tree). |
---|
742 | * @ path : pathname (absolute or relative to current directory). |
---|
743 | * @ rights : access rights. |
---|
744 | * @ returns 0 if success / -1 if error. |
---|
745 | *****************************************************************************************/ |
---|
746 | error_t vfs_mkdir( xptr_t root_xp, |
---|
747 | char * path, |
---|
748 | uint32_t rights ); |
---|
749 | |
---|
750 | /****************************************************************************************** |
---|
751 | * This function is called by the kernel to create in the file system a new directory |
---|
752 | * entry identified by the <new_root_xp> & <new_path> arguments, to be linked to an |
---|
753 | * existing inode, identified by the <old_root_xp> & <old_path> arguments. |
---|
754 | * If the link is successful, the link count of the target inode is incremented. |
---|
755 | * The <new_path> and <old_path> share equal access rights to the underlying inode. |
---|
756 | * Both the IOC device and the Inode Tree are modified. |
---|
757 | $ |
---|
758 | * TODO This function should handle any type of node, but the current implementation |
---|
759 | * handles only the FILE and DIR types. |
---|
760 | * |
---|
761 | * WARNING : this function takes & releases the remote_rwlock protecting the Inode Tree. |
---|
762 | ****************************************************************************************** |
---|
763 | * @ old_root_xp : extended pointer on old path root inode (any inode in Inode Tree). |
---|
764 | * @ old_path : old pathname (absolute or relative to current directory). |
---|
765 | * @ nld_root_xp : extended pointer on new path root inode (any inode in Inode Tree). |
---|
766 | * @ new_path : new pathname (absolute or relative to current directory). |
---|
767 | * @ returns 0 if success / -1 if error. |
---|
768 | *****************************************************************************************/ |
---|
769 | error_t vfs_link( xptr_t old_root_xp, |
---|
770 | char * old_path, |
---|
771 | xptr_t new_root_xp, |
---|
772 | char * new_path ); |
---|
773 | |
---|
774 | /****************************************************************************************** |
---|
775 | * This function is called by the kernel to remove from the file system a directory entry |
---|
776 | * identified by the <root_xp> & <path> arguments. |
---|
777 | * The link count of the target node is decremented. |
---|
778 | * If the removed link is the last, the target inode is deleted. |
---|
779 | * Both the IOC device and the Inode Tree are modified. |
---|
780 | * |
---|
781 | * TODO This function should handle any type of node, but the current implementation |
---|
782 | * handles only only the FILE and DIR types. |
---|
783 | * |
---|
784 | * WARNING : this function takes & releases the remote_rwlock protecting the Inode Tree. |
---|
785 | ****************************************************************************************** |
---|
786 | * @ root_xp : extended pointer on root inode (can be any inode in Inode Tree). |
---|
787 | * @ path : pathname (absolute or relative to current directory). |
---|
788 | * @ returns 0 if success / -1 if error. |
---|
789 | *****************************************************************************************/ |
---|
790 | error_t vfs_unlink( xptr_t root_xp, |
---|
791 | char * path ); |
---|
792 | |
---|
793 | /****************************************************************************************** |
---|
794 | * This function returns, in the structure pointed by the <st> pointer, various |
---|
795 | * informations on the inode identified by the <root_inode_xp> and <patname> arguments. |
---|
796 | * |
---|
797 | * TODO : only partially implemented yet (only size and inum fields). |
---|
798 | * |
---|
799 | * WARNING : this function takes & releases the remote_rwlock protecting the Inode Tree. |
---|
800 | ****************************************************************************************** |
---|
801 | * @ root_xp : extended pointer on path root inode (any inode in Inode Tree) |
---|
802 | * @ pathname : pathname to target inode. |
---|
803 | * @ st : local pointer on the stat structure in kernel space. |
---|
804 | * @ returns 0 if success / -1 if error. |
---|
805 | *****************************************************************************************/ |
---|
806 | error_t vfs_stat( xptr_t root_xp, |
---|
807 | char * pathname, |
---|
808 | struct stat * st ); |
---|
809 | |
---|
810 | /****************************************************************************************** |
---|
811 | * This function returns, in the structure pointed by the <k_dirent> kernel pointer, |
---|
812 | * various infos on the directory entry currently pointed by the <file_xp> file descriptor. |
---|
813 | * TODO not implemented yet... |
---|
814 | ****************************************************************************************** |
---|
815 | * @ file_xp : extended pointer on the file descriptor of the searched directory . |
---|
816 | * @ k_dirent : local pointer on the dirent structure in kernel space. |
---|
817 | * @ returns 0 if success / -1 if error. |
---|
818 | *****************************************************************************************/ |
---|
819 | error_t vfs_readdir( xptr_t file_xp, |
---|
820 | struct dirent * k_dirent ); |
---|
821 | |
---|
822 | /****************************************************************************************** |
---|
823 | * This function creates a new directory as defined by the <root_xp> & <path> arguments. |
---|
824 | * TODO not implemented yet... |
---|
825 | ****************************************************************************************** |
---|
826 | * @ root_xp : extended pointer on the path root directory. |
---|
827 | * @ path : pathname (absolute or relative to CWD). |
---|
828 | * @ mode : access rights (as defined by chmod) |
---|
829 | * @ returns 0 if success / -1 if error. |
---|
830 | *****************************************************************************************/ |
---|
831 | error_t vfs_mkdir( xptr_t root_xp, |
---|
832 | char * path, |
---|
833 | uint32_t mode ); |
---|
834 | |
---|
835 | /****************************************************************************************** |
---|
836 | * This function makes the directory identified by the <root_xp and <path> arguments |
---|
837 | * to become the working directory for the calling process. |
---|
838 | ****************************************************************************************** |
---|
839 | * @ root_xp : extended pointer on the path root directory. |
---|
840 | * @ path : pathname (absolute or relative to CWD). |
---|
841 | * return 0 if success / -1 if error. |
---|
842 | *****************************************************************************************/ |
---|
843 | error_t vfs_chdir( xptr_t root_xp, |
---|
844 | char * path ); |
---|
845 | |
---|
846 | /****************************************************************************************** |
---|
847 | * This function change the access rigths for the file/directory identified by the |
---|
848 | * <root_xp> and <path> arguments as defined by the <mode> argument value. |
---|
849 | ****************************************************************************************** |
---|
850 | * @ root_xp : extended pointer on the path root directory. |
---|
851 | * @ path : pathname (absolute or relative to CWD). |
---|
852 | * @ mode : access rights |
---|
853 | * return 0 if success / -1 if error. |
---|
854 | *****************************************************************************************/ |
---|
855 | error_t vfs_chmod( xptr_t root_xp, |
---|
856 | char * path, |
---|
857 | uint32_t mode ); |
---|
858 | |
---|
859 | /****************************************************************************************** |
---|
860 | * This function creates a named FIFO file. |
---|
861 | * TODO not implemented yet |
---|
862 | ****************************************************************************************** |
---|
863 | * @ root_xp : extended pointer on the path root directory. |
---|
864 | * @ path : pathname (absolute or relative to CWD). |
---|
865 | * @ mode : access rights new value. |
---|
866 | *****************************************************************************************/ |
---|
867 | error_t vfs_mkfifo( xptr_t root_xp, |
---|
868 | char * path, |
---|
869 | uint32_t mode ); |
---|
870 | |
---|
871 | |
---|
872 | |
---|
873 | /****************************************************************************************** |
---|
874 | * These functions define the VFS "FS" API (to a specific File System) |
---|
875 | *****************************************************************************************/ |
---|
876 | |
---|
877 | /****************************************************************************************** |
---|
878 | * This function updates the mapper associated to a directory inode identified by the |
---|
879 | * <parent> argument, to add a new entry identified by the <dentry> argument. |
---|
880 | * The directory inode descriptor and the dentry descriptor are in the same cluster. |
---|
881 | * Depending on the file system type, it calls the proper, FS specific function. |
---|
882 | * It ulso pdates the dentry descriptor and/or the inode descriptor extensions |
---|
883 | * as required by the specific file system type. |
---|
884 | * Finally, it synchronously updates the parent directory on IOC device. |
---|
885 | * |
---|
886 | * It must be executed by a thread running in the cluster containing the parent directory. |
---|
887 | * It can be the RPC_VFS_VS_ADD_DENTRY. This function does NOT take any lock. |
---|
888 | ****************************************************************************************** |
---|
889 | * @ parent : local pointer on parent (directory) inode. |
---|
890 | * @ dentry : local pointer on dentry containing name. |
---|
891 | * @ return 0 if success / return -1 if device access failure. |
---|
892 | *****************************************************************************************/ |
---|
893 | error_t vfs_fs_add_dentry( vfs_inode_t * parent, |
---|
894 | vfs_dentry_t * dentry ); |
---|
895 | |
---|
896 | /****************************************************************************************** |
---|
897 | * This function updates the mapper associated to a directory inode identified by the |
---|
898 | * <parent> argument, to remove an entry identified by the <dentry> argument. |
---|
899 | * The directory inode descriptor and the dentry descriptor are in the same cluster. |
---|
900 | * Depending on the file system type, it calls the proper, FS specific function. |
---|
901 | * Finally, it synchronously updates the parent directory on IOC device. |
---|
902 | * |
---|
903 | * It must be executed by a thread running in the cluster containing the parent directory. |
---|
904 | * It can be the RPC_VFS_VS_REMOVE_DENTRY. This function does NOT take any lock. |
---|
905 | ****************************************************************************************** |
---|
906 | * @ parent : local pointer on parent (directory) inode. |
---|
907 | * @ dentry : local pointer on dentry containing name. |
---|
908 | * @ return 0 if success / return -1 if device access failure. |
---|
909 | *****************************************************************************************/ |
---|
910 | error_t vfs_fs_remove_dentry( vfs_inode_t * parent, |
---|
911 | vfs_dentry_t * dentry ); |
---|
912 | |
---|
913 | /****************************************************************************************** |
---|
914 | * This function scan the mapper of an an existing parent inode directory, identified by |
---|
915 | * the <parent> argument to find a directory entry identified by the <name> argument, |
---|
916 | * and updates both the child inode descriptor, identified by the <child_xp> argument, |
---|
917 | * and the associated dentry descriptor : |
---|
918 | * - It set the "size", and "extend" fields in inode descriptor. |
---|
919 | * - It set the "extend" field in dentry descriptor. |
---|
920 | * It is called by the vfs_lookup() function in case of miss. |
---|
921 | * |
---|
922 | * Depending on the file system type, it calls the relevant, FS specific function. |
---|
923 | * It must be called by a thread running in the cluster containing the parent inode. |
---|
924 | * This function does NOT take any lock. |
---|
925 | ****************************************************************************************** |
---|
926 | * @ parent : local pointer on parent inode (directory). |
---|
927 | * @ name : child name. |
---|
928 | * @ child_xp : extended pointer on remote child inode (file or directory) |
---|
929 | * @ return 0 if success / return ENOENT if not found. |
---|
930 | *****************************************************************************************/ |
---|
931 | error_t vfs_fs_child_init( vfs_inode_t * parent, |
---|
932 | char * name, |
---|
933 | xptr_t child_xp ); |
---|
934 | |
---|
935 | /***************************************************************************************** |
---|
936 | * This function updates the FS on the IOC device for a given inode identified by |
---|
937 | * the <inode> argument. It scan all pages registered in the associated mapper, |
---|
938 | * and copies from mapper to device each page marked as dirty. |
---|
939 | * WARNING : The target <inode> cannot be a directory, because all modifications in a |
---|
940 | * directory are synchronously done on the IOC device by the two vfs_fs_add_dentry() |
---|
941 | * and vfs_fs_remove_dentry() functions. |
---|
942 | * |
---|
943 | * Depending on the file system type, it calls the relevant, FS specific function. |
---|
944 | * It must be called by a thread running in the inode cluster. |
---|
945 | ***************************************************************************************** |
---|
946 | * @ inode : local pointer on inode. |
---|
947 | * @ return 0 if success / return EIO if failure during device access. |
---|
948 | ****************************************************************************************/ |
---|
949 | error_t vfs_fs_sync_inode( struct vfs_inode_s * inode ); |
---|
950 | |
---|
951 | /***************************************************************************************** |
---|
952 | * This function updates the FS defined by the <fs_type> argument on the IOC device |
---|
953 | * for the FAT itself. It scan all clusters registered in the FAT mapper, and copies |
---|
954 | * to device each page marked as dirty. |
---|
955 | * |
---|
956 | * Depending on the file system type, it calls the relevant, FS specific function. |
---|
957 | * It can be called by a thread running in any cluster. |
---|
958 | ***************************************************************************************** |
---|
959 | * @ fs_type : specific file system type. |
---|
960 | * @ return 0 if success / return EIO if failure during device access. |
---|
961 | ****************************************************************************************/ |
---|
962 | error_t vfs_fs_sync_fat( vfs_fs_type_t fs_type ); |
---|
963 | |
---|
964 | /***************************************************************************************** |
---|
965 | * This function updates the free clusters info on the IOC device for the FS defined |
---|
966 | * by the <fs_type> argument. |
---|
967 | * |
---|
968 | * Depending on the file system type, it calls the relevant, FS specific function. |
---|
969 | * It can be called by a thread running in any cluster. |
---|
970 | ***************************************************************************************** |
---|
971 | * @ fs_type : specific file system type. |
---|
972 | * @ return 0 if success / return EIO if failure during device access. |
---|
973 | ****************************************************************************************/ |
---|
974 | error_t vfs_fs_sync_free_info( vfs_fs_type_t fs_type ); |
---|
975 | |
---|
976 | /****************************************************************************************** |
---|
977 | * This function allocates a free cluster from the FS identified by the <fs_type> |
---|
978 | * argument. It updates the selected FS File Allocation Table. |
---|
979 | * |
---|
980 | * Depending on the file system type, it calls the relevant, FS specific function. |
---|
981 | * It can be called by a thread running in any cluster. |
---|
982 | ****************************************************************************************** |
---|
983 | * @ fs_type : [in] File System type. |
---|
984 | * @ cluster : [out] cluster index in File system. |
---|
985 | * @ return 0 if success / return -1 if no free cluster |
---|
986 | *****************************************************************************************/ |
---|
987 | error_t vfs_fs_cluster_alloc( uint32_t fs_type, |
---|
988 | uint32_t * cluster ); |
---|
989 | |
---|
990 | /****************************************************************************************** |
---|
991 | * This function makes all I/O operations required to release all clusters allocated |
---|
992 | * on IOC device to a given inode, identified by the <inode_xp> argument. |
---|
993 | * Depending on the file system type, it calls the proper, FS specific function. |
---|
994 | * It is called by the vfs_unlink() function. |
---|
995 | * It can be executed by a thread running in any cluster. |
---|
996 | * This function does NOT take any lock. |
---|
997 | ****************************************************************************************** |
---|
998 | * @ inode_xp : extended pointer on inode. |
---|
999 | * @ return 0 if success / return -1 if device access failure. |
---|
1000 | *****************************************************************************************/ |
---|
1001 | error_t vfs_fs_release_inode( xptr_t inode_xp ); |
---|
1002 | |
---|
1003 | /****************************************************************************************** |
---|
1004 | * This function makes the I/O operation to move one page identified by the <page_xp> |
---|
1005 | * argument to/from the IOC device from/to the mapper, as defined by <to_mapper>. |
---|
1006 | * Depending on the file system type, it calls the proper, FS specific function. |
---|
1007 | * It is used in case of MISS on the mapper, or when a dirty page in the mapper must |
---|
1008 | * be updated in the File System. |
---|
1009 | * The mapper pointer is obtained from the page descriptor. |
---|
1010 | * It can be executed by any thread running in any cluster. |
---|
1011 | * This function does NOT take any lock. |
---|
1012 | ****************************************************************************************** |
---|
1013 | * @ page_xp : extended pointer on the page descriptor. |
---|
1014 | * @ to_mapper : transfer direction. |
---|
1015 | * @ returns 0 if success / return -1 if device access failure. |
---|
1016 | *****************************************************************************************/ |
---|
1017 | error_t vfs_fs_move_page( xptr_t page_xp, |
---|
1018 | bool_t to_mapper ); |
---|
1019 | |
---|
1020 | |
---|
1021 | #endif /* _VFS_H_ */ |
---|