/filesystems/unixfs/sysvfs/sysvfs.h
C++ Header | 328 lines | 248 code | 43 blank | 37 comment | 8 complexity | 33321553868b1fafdb20a713f1550bc0 MD5 | raw file
1/* 2 * SYSV File System Famiy for MacFUSE 3 * Amit Singh 4 * http://osxbook.com 5 * 6 * Most of the code in this file comes from the Linux kernel implementation 7 * of sysvfs. See fs/sysv/ in the Linux kernel source tree. 8 * 9 * The code is Copyright (c) its various authors. It is covered by the 10 * GNU GENERAL PUBLIC LICENSE Version 2. 11 */ 12 13#ifndef _SYSVFS_H_ 14#define _SYSVFS_H_ 15 16#include "unixfs_internal.h" 17#include "linux.h" 18 19#include <stdio.h> 20#include <sys/types.h> 21#include <stdint.h> 22#include <sys/time.h> 23#include <sys/errno.h> 24#include <stdlib.h> 25#include <unistd.h> 26#include <string.h> 27 28/* Heuristic timestamp used to distinguish between SVR4 and SVR2 */ 29enum { 30 JAN_1_1980 = (10*365 + 2) * 24 * 60 * 60 31}; 32 33typedef __fs16 sysv_ino_t; /* inode numbers are 16 bit */ 34typedef __fs32 sysv_zone_t; /* block numbers are 24 bit */ 35 36#define SYSV_INVAL_INO 0 /* inode 0 does not exist */ 37#define SYSV_BADBL_INO 1 /* inode of bad blocks file */ 38#define SYSV_ROOT_INO 2 /* inode of root directory */ 39 40struct sysv_dinode { /* on disk */ 41 __fs16 di_mode; 42 __fs16 di_nlink; 43 __fs16 di_uid; 44 __fs16 di_gid; 45 __fs32 di_size; 46 u8 di_data[3 * (10 + 1 + 1 + 1)]; 47 u8 di_gen; 48 __fs32 di_atime; 49 __fs32 di_mtime; 50 __fs32 di_ctime; 51}; 52 53struct sysv_inode_info { /* in memory */ 54 __fs32 i_data[13]; 55 u32 i_dir_start_lookup; 56}; 57 58static inline struct sysv_inode_info* 59SYSV_I(struct inode* inode) 60{ 61 return (struct sysv_inode_info*)&(inode[1]); 62} 63 64#define SYSV_NAMELEN 14 65 66struct sysv_dir_entry { /* on disk */ 67 sysv_ino_t inode; 68 char name[SYSV_NAMELEN]; 69}; 70 71#define SYSV_DIRSIZE sizeof(struct sysv_dir_entry) 72 73static inline int 74sysv_namecompare(int len, int maxlen, const char* name, const char* buffer) 75{ 76 if (len < maxlen && buffer[len]) 77 return 0; 78 return !memcmp(name, buffer, len); 79} 80 81static inline unsigned long 82sysv_dir_pages(struct inode* inode) 83{ 84 return (inode->I_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; 85} 86 87struct sysv_sb_info { /* in memory */ 88 89 struct super_block* s_sb; /* VFS superblock */ 90 91 int s_type; /* file system type: FSTYPE_{XENIX|SYSV|COH} */ 92 char s_bytesex; /* bytesex (le/be/pdp) */ 93 char s_truncate; /* if 1: names > SYSV_NAMELEN chars are truncated */ 94 /* if 0: they are disallowed (ENAMETOOLONG) */ 95 96 nlink_t s_link_max; /* max # of hard links to a file */ 97 unsigned int s_inodes_per_block; /* # of inodes per block */ 98 unsigned int s_inodes_per_block_1; /* inodes_per_block - 1 */ 99 unsigned int s_inodes_per_block_bits; /* log2(inodes_per_block) */ 100 unsigned int s_ind_per_block; /* # of indirections per block */ 101 unsigned int s_ind_per_block_bits; /* log2(ind_per_block) */ 102 unsigned int s_ind_per_block_2; /* ind_per_block ^ 2 */ 103 unsigned int s_toobig_block; /* 10 + ipb + ipb^2 + ipb^3 */ 104 unsigned int s_block_base; /* physical block # of block 0 */ 105 unsigned short s_fic_size; /* free inode cache size, NICINOD */ 106 unsigned short s_flc_size; /* free block list chunk size, NICFREE */ 107 108 struct buffer_head* s_bh1; /* disk buffer 1 for holding superblock */ 109 struct buffer_head* s_bh2; /* disk buffer 2 for holding superblock */ 110 111 char* s_sbd1; /* entire superblock data, part 1 */ 112 char* s_sbd2; /* entire superblock data, part 2 */ 113 __fs16* s_sb_fic_count; /* pointer to s_sbd->s_ninode */ 114 sysv_ino_t* s_sb_fic_inodes; /* pointer to s_sbd->s_inode */ 115 __fs16* s_sb_total_free_inodes; /* pointer to s_sbd->s_tinode */ 116 __fs16* s_bcache_count; /* pointer to s_sbd->s_nfree */ 117 sysv_zone_t* s_bcache; /* pointer to s_sbd->s_free */ 118 __fs32* s_free_blocks; /* pointer to s_sbd->s_tfree */ 119 __fs32* s_sb_time; /* pointer to s_sbd->s_time */ 120 __fs32* s_sb_state; /* pointer to s_sbd->s_state, only FSTYPE_SYSV */ 121 122 /* The following superblock entities don't change. */ 123 124 u32 s_firstinodezone; /* index of first inode zone */ 125 u32 s_firstdatazone; /* same as s_sbd->s_isize */ 126 u32 s_ninodes; /* total number of inodes */ 127 u32 s_ndatazones; /* total number of data zones */ 128 u32 s_nzones; /* same as s_sbd->s_fsize */ 129 u16 s_namelen; /* max length of dir entry */ 130 int s_forced_ro; 131}; 132 133static inline struct sysv_sb_info* 134SYSV_SB(struct super_block* sb) 135{ 136 return (struct sysv_sb_info*)sb->s_fs_info; 137} 138 139static inline void 140sysv_read3byte(struct sysv_sb_info* sbi, unsigned char* from, unsigned char* to) 141{ 142 if (sbi->s_bytesex == UNIXFS_FS_PDP) { 143 to[0] = from[0]; 144 to[1] = 0; 145 to[2] = from[1]; 146 to[3] = from[2]; 147 } else if (sbi->s_bytesex == UNIXFS_FS_LITTLE) { 148 to[0] = from[0]; 149 to[1] = from[1]; 150 to[2] = from[2]; 151 to[3] = 0; 152 } else { 153 to[0] = 0; 154 to[1] = from[0]; 155 to[2] = from[1]; 156 to[3] = from[2]; 157 } 158} 159 160/* in-memory file system type identifiers */ 161enum { 162 FSTYPE_NONE = 0, 163 FSTYPE_XENIX, 164 FSTYPE_SYSV4, 165 FSTYPE_SYSV2, 166 FSTYPE_COH, 167 FSTYPE_V7, 168 FSTYPE_AFS, 169 FSTYPE_END, 170}; 171 172#define SYSV_MAGIC_BASE 0x012FF7B3 173#define XENIX_SUPER_MAGIC (SYSV_MAGIC_BASE + FSTYPE_XENIX) 174#define SYSV4_SUPER_MAGIC (SYSV_MAGIC_BASE + FSTYPE_SYSV4) 175#define SYSV2_SUPER_MAGIC (SYSV_MAGIC_BASE + FSTYPE_SYSV2) 176#define COH_SUPER_MAGIC (SYSV_MAGIC_BASE + FSTYPE_COH) 177 178/* admissible values for i_nlink: 0.._LINK_MAX */ 179enum { 180 XENIX_LINK_MAX = 126, /* ?? */ 181 SYSV_LINK_MAX = 126, /* 127? 251? */ 182 V7_LINK_MAX = 126, /* ?? */ 183 COH_LINK_MAX = 10000, 184}; 185 186/* 187 * Xenix 188 */ 189 190#define XENIX_NICINOD 100 /* number of inode cache entries */ 191#define XENIX_NICFREE 100 /* number of free block list chunk entries */ 192 193struct xenix_super_block { /* on disk */ 194 __fs16 s_isize; /* index of first data zone */ 195 __fs32 s_fsize __packed2__; /* total number of zones of this fs */ 196 __fs16 s_nfree; /* # of free blocks in s_free, <= XENIX_NICFREE */ 197 sysv_zone_t s_free[XENIX_NICFREE]; /* first free block list chunk */ 198 __fs16 s_ninode; /* # of free inodes in s_inode, <= XENIX_NICINOD */ 199 sysv_ino_t s_inode[XENIX_NICINOD]; /* some free inodes */ 200 char s_flock; /* lock during free block list manipulation */ 201 char s_ilock; /* lock during inode cache manipulation */ 202 char s_fmod; /* super-block modified flag */ 203 char s_ronly; /* flag whether fs is mounted read-only */ 204 __fs32 s_time __packed2__; /* time of last super block update */ 205 __fs32 s_tfree __packed2__; /* total number of free zones */ 206 __fs16 s_tinode; /* total number of free inodes */ 207 __fs16 s_dinfo[4]; /* device information ?? */ 208 char s_fname[6]; /* file system volume name */ 209 char s_fpack[6]; /* file system pack name */ 210 char s_clean; /* set to 0x46 when fs was properly unmounted */ 211 char s_fill[371]; 212 s32 s_magic; /* version of file system */ 213 __fs32 s_type ; /* type of file system: 214 1 for 512 byte blocks 215 2 for 1024 byte blocks 216 3 for 2048 byte blocks */ 217 218}; 219 220/* 221 * System V 222 */ 223 224/* 225 * System V FS comes in two variants: 226 * sysv2: System V Release 2 (e.g. Microport), structure elements aligned(2). 227 * sysv4: System V Release 4 (e.g. Consensys), structure elements aligned(4). 228 */ 229 230#define SYSV_NICINOD 100 /* number of inode cache entries */ 231#define SYSV_NICFREE 50 /* number of free block list chunk entries */ 232 233struct sysv4_super_block { /* on disk */ 234 __fs16 s_isize; /* index of first data zone */ 235 u16 s_pad0; 236 __fs32 s_fsize; /* total number of zones of this fs */ 237 __fs16 s_nfree; /* # of free blocks in s_free, <= SYSV_NICFREE */ 238 u16 s_pad1; 239 sysv_zone_t s_free[SYSV_NICFREE]; /* first free block list chunk */ 240 __fs16 s_ninode; /* # of free inodes in s_inode, <= SYSV_NICINOD */ 241 u16 s_pad2; 242 sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */ 243 char s_flock; /* lock during free block list manipulation */ 244 char s_ilock; /* lock during inode cache manipulation */ 245 char s_fmod; /* super-block modified flag */ 246 char s_ronly; /* flag whether fs is mounted read-only */ 247 __fs32 s_time; /* time of last super block update */ 248 __fs16 s_dinfo[4]; /* device information ?? */ 249 __fs32 s_tfree; /* total number of free zones */ 250 __fs16 s_tinode; /* total number of free inodes */ 251 u16 s_pad3; 252 char s_fname[6]; /* file system volume name */ 253 char s_fpack[6]; /* file system pack name */ 254 s32 s_fill[12]; 255 __fs32 s_state; /* state: 0x7c269d38-s_time means it is clean */ 256 s32 s_magic; /* version of file system */ 257 __fs32 s_type; /* type of file system: 258 1 for 512 byte blocks 259 2 for 1024 byte blocks */ 260}; 261 262struct sysv2_super_block { /* on disk */ 263 __fs16 s_isize; /* index of first data zone */ 264 __fs32 s_fsize __packed2__; /* total number of zones of this fs */ 265 __fs16 s_nfree; /* # of free blocks in s_free, <= SYSV_NICFREE */ 266 sysv_zone_t s_free[SYSV_NICFREE]; /* first free block list chunk */ 267 __fs16 s_ninode; /* # of free inodes in s_inode, <= SYSV_NICINOD */ 268 sysv_ino_t s_inode[SYSV_NICINOD]; /* some free inodes */ 269 char s_flock; /* lock during free block list manipulation */ 270 char s_ilock; /* lock during inode cache manipulation */ 271 char s_fmod; /* super-block modified flag */ 272 char s_ronly; /* flag whether fs is mounted read-only */ 273 __fs32 s_time __packed2__; /* time of last super block update */ 274 __fs16 s_dinfo[4]; /* device information ?? */ 275 __fs32 s_tfree __packed2__; /* total number of free zones */ 276 __fs16 s_tinode; /* total number of free inodes */ 277 char s_fname[6]; /* file system volume name */ 278 char s_fpack[6]; /* file system pack name */ 279 s32 s_fill[14]; 280 __fs32 s_state; /* file system state: 0xcb096f43 means clean */ 281 s32 s_magic; /* version of file system */ 282 __fs32 s_type; /* type of file system: 283 1 for 512 byte blocks 284 2 for 1024 byte blocks */ 285}; 286 287/* 288 * Coherent 289 */ 290 291#define COH_NICINOD 100 /* number of inode cache entries */ 292#define COH_NICFREE 64 /* number of free block list chunk entries */ 293 294struct coh_super_block { /* on disk */ 295 __fs16 s_isize; /* index of first data zone */ 296 __fs32 s_fsize __packed2__; /* total number of zones of this fs */ 297 __fs16 s_nfree; /* # of free blocks in s_free, <= COH_NICFREE */ 298 sysv_zone_t s_free[COH_NICFREE] __packed2__; /* 1st free block list chunk */ 299 __fs16 s_ninode; /* # of free inodes in s_inode, <= COH_NICINOD */ 300 sysv_ino_t s_inode[COH_NICINOD]; /* some free inodes */ 301 char s_flock; /* lock during free block list manipulation */ 302 char s_ilock; /* lock during inode cache manipulation */ 303 char s_fmod; /* super-block modified flag */ 304 char s_ronly; /* flag whether fs is mounted read-only */ 305 __fs32 s_time __packed2__; /* time of last super block update */ 306 __fs32 s_tfree __packed2__; /* total number of free zones */ 307 __fs16 s_tinode; /* total number of free inodes */ 308 __fs16 s_interleave_m; /* interleave factor */ 309 __fs16 s_interleave_n; 310 char s_fname[6]; /* file system volume name */ 311 char s_fpack[6]; /* file system pack name */ 312 __fs32 s_unique; /* zero, not used */ 313}; 314 315struct super_block* sysv_fill_super(int fd, void* args, int silent); 316const char* sysv_flavor(u_int type); 317u_long sysv_count_free_blocks(struct super_block* sb); 318u_long sysv_count_free_inodes(struct super_block* sb); 319 320struct sysv_dinode* sysv_raw_inode(struct super_block* sb, ino_t ino, 321 struct buffer_head* bh); 322int sysv_next_direntry(struct inode* dp, struct unixfs_dirbuf* dirbuf, 323 off_t* offset, struct unixfs_direntry* dent); 324 325int sysv_get_block(struct inode* ip, sector_t block, off_t* result); 326int sysv_get_page(struct inode* ip, sector_t index, char* pagebuf); 327 328#endif /* _SYSVFS_H_ */