1/* 2 * linux/fs/adfs/inode.c 3 * 4 * Copyright (C) 1997-1999 Russell King 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10#include <linux/errno.h> 11#include <linux/fs.h> 12#include <linux/adfs_fs.h> 13#include <linux/time.h> 14#include <linux/stat.h> 15#include <linux/string.h> 16#include <linux/mm.h> 17#include <linux/smp_lock.h> 18#include <linux/module.h> 19#include <linux/buffer_head.h> 20 21#include "adfs.h" 22 23/* 24 * Lookup/Create a block at offset 'block' into 'inode'. We currently do 25 * not support creation of new blocks, so we return -EIO for this case. 26 */ 27static int 28adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh, 29 int create) 30{ 31 if (block < 0) 32 goto abort_negative; 33 34 if (!create) { 35 if (block >= inode->i_blocks) 36 goto abort_toobig; 37 38 block = __adfs_block_map(inode->i_sb, inode->i_ino, block); 39 if (block) 40 map_bh(bh, inode->i_sb, block); 41 return 0; 42 } 43 /* don't support allocation of blocks yet */ 44 return -EIO; 45 46abort_negative: 47 adfs_error(inode->i_sb, "block %d < 0", block); 48 return -EIO; 49 50abort_toobig: 51 return 0; 52} 53 54static int adfs_writepage(struct page *page, struct writeback_control *wbc) 55{ 56 return block_write_full_page(page, adfs_get_block, wbc); 57} 58 59static int adfs_readpage(struct file *file, struct page *page) 60{ 61 return block_read_full_page(page, adfs_get_block); 62} 63 64static int adfs_prepare_write(struct file *file, struct page *page, unsigned int from, unsigned int to) 65{ 66 return cont_prepare_write(page, from, to, adfs_get_block, 67 &ADFS_I(page->mapping->host)->mmu_private); 68} 69 70static sector_t _adfs_bmap(struct address_space *mapping, sector_t block) 71{ 72 return generic_block_bmap(mapping, block, adfs_get_block); 73} 74 75static const struct address_space_operations adfs_aops = { 76 .readpage = adfs_readpage, 77 .writepage = adfs_writepage, 78 .sync_page = block_sync_page, 79 .prepare_write = adfs_prepare_write, 80 .commit_write = generic_commit_write, 81 .bmap = _adfs_bmap 82}; 83 84static inline unsigned int 85adfs_filetype(struct inode *inode) 86{ 87 unsigned int type; 88 89 if (ADFS_I(inode)->stamped) 90 type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff; 91 else 92 type = (unsigned int) -1; 93 94 return type; 95} 96 97/* 98 * Convert ADFS attributes and filetype to Linux permission. 99 */ 100static umode_t 101adfs_atts2mode(struct super_block *sb, struct inode *inode) 102{ 103 unsigned int filetype, attr = ADFS_I(inode)->attr; 104 umode_t mode, rmask; 105 struct adfs_sb_info *asb = ADFS_SB(sb); 106 107 if (attr & ADFS_NDA_DIRECTORY) { 108 mode = S_IRUGO & asb->s_owner_mask; 109 return S_IFDIR | S_IXUGO | mode; 110 } 111 112 filetype = adfs_filetype(inode); 113 114 switch (filetype) { 115 case 0xfc0: /* LinkFS */ 116 return S_IFLNK|S_IRWXUGO; 117 118 case 0xfe6: /* UnixExec */ 119 rmask = S_IRUGO | S_IXUGO; 120 break; 121 122 default: 123 rmask = S_IRUGO; 124 } 125 126 mode = S_IFREG; 127 128 if (attr & ADFS_NDA_OWNER_READ) 129 mode |= rmask & asb->s_owner_mask; 130 131 if (attr & ADFS_NDA_OWNER_WRITE) 132 mode |= S_IWUGO & asb->s_owner_mask; 133 134 if (attr & ADFS_NDA_PUBLIC_READ) 135 mode |= rmask & asb->s_other_mask; 136 137 if (attr & ADFS_NDA_PUBLIC_WRITE) 138 mode |= S_IWUGO & asb->s_other_mask; 139 return mode; 140} 141 142/* 143 * Convert Linux permission to ADFS attribute. We try to do the reverse 144 * of atts2mode, but there is not a 1:1 translation. 145 */ 146static int 147adfs_mode2atts(struct super_block *sb, struct inode *inode) 148{ 149 umode_t mode; 150 int attr; 151 struct adfs_sb_info *asb = ADFS_SB(sb); 152 153 if (S_ISLNK(inode->i_mode)) 154 return ADFS_I(inode)->attr; 155 156 if (S_ISDIR(inode->i_mode)) 157 attr = ADFS_NDA_DIRECTORY; 158 else 159 attr = 0; 160 161 mode = inode->i_mode & asb->s_owner_mask; 162 if (mode & S_IRUGO) 163 attr |= ADFS_NDA_OWNER_READ; 164 if (mode & S_IWUGO) 165 attr |= ADFS_NDA_OWNER_WRITE; 166 167 mode = inode->i_mode & asb->s_other_mask; 168 mode &= ~asb->s_owner_mask; 169 if (mode & S_IRUGO) 170 attr |= ADFS_NDA_PUBLIC_READ; 171 if (mode & S_IWUGO) 172 attr |= ADFS_NDA_PUBLIC_WRITE; 173 174 return attr; 175} 176 177/* 178 * Convert an ADFS time to Unix time. ADFS has a 40-bit centi-second time 179 * referenced to 1 Jan 1900 (til 2248) 180 */ 181static void 182adfs_adfs2unix_time(struct timespec *tv, struct inode *inode) 183{ 184 unsigned int high, low; 185 186 if (ADFS_I(inode)->stamped == 0) 187 goto cur_time; 188 189 high = ADFS_I(inode)->loadaddr << 24; 190 low = ADFS_I(inode)->execaddr; 191 192 high |= low >> 8; 193 low &= 255; 194 195 /* Files dated pre 01 Jan 1970 00:00:00. */ 196 if (high < 0x336e996a) 197 goto too_early; 198 199 /* Files dated post 18 Jan 2038 03:14:05. */ 200 if (high >= 0x656e9969) 201 goto too_late; 202 203 /* discard 2208988800 (0x336e996a00) seconds of time */ 204 high -= 0x336e996a; 205 206 /* convert 40-bit centi-seconds to 32-bit seconds */ 207 tv->tv_sec = (((high % 100) << 8) + low) / 100 + (high / 100 << 8); 208 tv->tv_nsec = 0; 209 return; 210 211 cur_time: 212 *tv = CURRENT_TIME_SEC; 213 return; 214 215 too_early: 216 tv->tv_sec = tv->tv_nsec = 0; 217 return; 218 219 too_late: 220 tv->tv_sec = 0x7ffffffd; 221 tv->tv_nsec = 0; 222 return; 223} 224 225/* 226 * Convert an Unix time to ADFS time. We only do this if the entry has a 227 * time/date stamp already. 228 */ 229static void 230adfs_unix2adfs_time(struct inode *inode, unsigned int secs) 231{ 232 unsigned int high, low; 233 234 if (ADFS_I(inode)->stamped) { 235 /* convert 32-bit seconds to 40-bit centi-seconds */ 236 low = (secs & 255) * 100; 237 high = (secs / 256) * 100 + (low >> 8) + 0x336e996a; 238 239 ADFS_I(inode)->loadaddr = (high >> 24) | 240 (ADFS_I(inode)->loadaddr & ~0xff); 241 ADFS_I(inode)->execaddr = (low & 255) | (high << 8); 242 } 243} 244 245/* 246 * Fill in the inode information from the object information. 247 * 248 * Note that this is an inode-less filesystem, so we can't use the inode 249 * number to reference the metadata on the media. Instead, we use the 250 * inode number to hold the object ID, which in turn will tell us where 251 * the data is held. We also save the parent object ID, and with these 252 * two, we can locate the metadata. 253 * 254 * This does mean that we rely on an objects parent remaining the same at 255 * all times - we cannot cope with a cross-directory rename (yet). 256 */ 257struct inode * 258adfs_iget(struct super_block *sb, struct object_info *obj) 259{ 260 struct inode *inode; 261 262 inode = new_inode(sb); 263 if (!inode) 264 goto out; 265 266 inode->i_uid = ADFS_SB(sb)->s_uid; 267 inode->i_gid = ADFS_SB(sb)->s_gid; 268 inode->i_ino = obj->file_id; 269 inode->i_size = obj->size; 270 inode->i_nlink = 2; 271 inode->i_blocks = (inode->i_size + sb->s_blocksize - 1) >> 272 sb->s_blocksize_bits; 273 274 /* 275 * we need to save the parent directory ID so that 276 * write_inode can update the directory information 277 * for this file. This will need special handling 278 * for cross-directory renames. 279 */ 280 ADFS_I(inode)->parent_id = obj->parent_id; 281 ADFS_I(inode)->loadaddr = obj->loadaddr; 282 ADFS_I(inode)->execaddr = obj->execaddr; 283 ADFS_I(inode)->attr = obj->attr; 284 ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000); 285 286 inode->i_mode = adfs_atts2mode(sb, inode); 287 adfs_adfs2unix_time(&inode->i_mtime, inode); 288 inode->i_atime = inode->i_mtime; 289 inode->i_ctime = inode->i_mtime; 290 291 if (S_ISDIR(inode->i_mode)) { 292 inode->i_op = &adfs_dir_inode_operations; 293 inode->i_fop = &adfs_dir_operations; 294 } else if (S_ISREG(inode->i_mode)) { 295 inode->i_op = &adfs_file_inode_operations; 296 inode->i_fop = &adfs_file_operations; 297 inode->i_mapping->a_ops = &adfs_aops; 298 ADFS_I(inode)->mmu_private = inode->i_size; 299 } 300 301 insert_inode_hash(inode); 302 303out: 304 return inode; 305} 306 307/* 308 * Validate and convert a changed access mode/time to their ADFS equivalents. 309 * adfs_write_inode will actually write the information back to the directory 310 * later. 311 */ 312int 313adfs_notify_change(struct dentry *dentry, struct iattr *attr) 314{ 315 struct inode *inode = dentry->d_inode; 316 struct super_block *sb = inode->i_sb; 317 unsigned int ia_valid = attr->ia_valid; 318 int error; 319 320 lock_kernel(); 321 322 error = inode_change_ok(inode, attr); 323 324 /* 325 * we can't change the UID or GID of any file - 326 * we have a global UID/GID in the superblock 327 */ 328 if ((ia_valid & ATTR_UID && attr->ia_uid != ADFS_SB(sb)->s_uid) || 329 (ia_valid & ATTR_GID && attr->ia_gid != ADFS_SB(sb)->s_gid)) 330 error = -EPERM; 331 332 if (error) 333 goto out; 334 335 if (ia_valid & ATTR_SIZE) 336 error = vmtruncate(inode, attr->ia_size); 337 338 if (error) 339 goto out; 340 341 if (ia_valid & ATTR_MTIME) { 342 inode->i_mtime = attr->ia_mtime; 343 adfs_unix2adfs_time(inode, attr->ia_mtime.tv_sec); 344 } 345 if (ia_valid & ATTR_ATIME) 346 inode->i_atime = attr->ia_atime; 347 if (ia_valid & ATTR_CTIME) 348 inode->i_ctime = attr->ia_ctime; 349 if (ia_valid & ATTR_MODE) { 350 ADFS_I(inode)->attr = adfs_mode2atts(sb, inode); 351 inode->i_mode = adfs_atts2mode(sb, inode); 352 } 353 354 if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE)) 355 mark_inode_dirty(inode); 356out: 357 unlock_kernel(); 358 return error; 359} 360 361/* 362 * write an existing inode back to the directory, and therefore the disk. 363 * The adfs-specific inode data has already been updated by 364 * adfs_notify_change() 365 */ 366int adfs_write_inode(struct inode *inode, int unused) 367{ 368 struct super_block *sb = inode->i_sb; 369 struct object_info obj; 370 int ret; 371 372 lock_kernel(); 373 obj.file_id = inode->i_ino; 374 obj.name_len = 0; 375 obj.parent_id = ADFS_I(inode)->parent_id; 376 obj.loadaddr = ADFS_I(inode)->loadaddr; 377 obj.execaddr = ADFS_I(inode)->execaddr; 378 obj.attr = ADFS_I(inode)->attr; 379 obj.size = inode->i_size; 380 381 ret = adfs_dir_update(sb, &obj); 382 unlock_kernel(); 383 return ret; 384} 385MODULE_LICENSE("GPL"); 386