1 /* 2 * linux/fs/minix/inode.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 * 6 * Copyright (C) 1996 Gertjan van Wingerde (gertjan@cs.vu.nl) 7 * Minix V2 fs support. 8 * 9 * Modified for 680x0 by Andreas Schwab 10 * Updated to filesystem version 3 by Daniel Aragones 11 */ 12 13 #include <linux/module.h> 14 #include "minix.h" 15 #include <linux/buffer_head.h> 16 #include <linux/slab.h> 17 #include <linux/init.h> 18 #include <linux/highuid.h> 19 #include <linux/vfs.h> 20 21 static void minix_read_inode(struct inode * inode); 22 static int minix_write_inode(struct inode * inode, int wait); 23 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf); 24 static int minix_remount (struct super_block * sb, int * flags, char * data); 25 26 static void minix_delete_inode(struct inode *inode) 27 { 28 truncate_inode_pages(&inode->i_data, 0); 29 inode->i_size = 0; 30 minix_truncate(inode); 31 minix_free_inode(inode); 32 } 33 34 static void minix_put_super(struct super_block *sb) 35 { 36 int i; 37 struct minix_sb_info *sbi = minix_sb(sb); 38 39 if (!(sb->s_flags & MS_RDONLY)) { 40 if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */ 41 sbi->s_ms->s_state = sbi->s_mount_state; 42 mark_buffer_dirty(sbi->s_sbh); 43 } 44 for (i = 0; i < sbi->s_imap_blocks; i++) 45 brelse(sbi->s_imap[i]); 46 for (i = 0; i < sbi->s_zmap_blocks; i++) 47 brelse(sbi->s_zmap[i]); 48 brelse (sbi->s_sbh); 49 kfree(sbi->s_imap); 50 sb->s_fs_info = NULL; 51 kfree(sbi); 52 53 return; 54 } 55 56 static struct kmem_cache * minix_inode_cachep; 57 58 static struct inode *minix_alloc_inode(struct super_block *sb) 59 { 60 struct minix_inode_info *ei; 61 ei = (struct minix_inode_info *)kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL); 62 if (!ei) 63 return NULL; 64 return &ei->vfs_inode; 65 } 66 67 static void minix_destroy_inode(struct inode *inode) 68 { 69 kmem_cache_free(minix_inode_cachep, minix_i(inode)); 70 } 71 72 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) 73 { 74 struct minix_inode_info *ei = (struct minix_inode_info *) foo; 75 76 inode_init_once(&ei->vfs_inode); 77 } 78 79 static int init_inodecache(void) 80 { 81 minix_inode_cachep = kmem_cache_create("minix_inode_cache", 82 sizeof(struct minix_inode_info), 83 0, (SLAB_RECLAIM_ACCOUNT| 84 SLAB_MEM_SPREAD), 85 init_once, NULL); 86 if (minix_inode_cachep == NULL) 87 return -ENOMEM; 88 return 0; 89 } 90 91 static void destroy_inodecache(void) 92 { 93 kmem_cache_destroy(minix_inode_cachep); 94 } 95 96 static const struct super_operations minix_sops = { 97 .alloc_inode = minix_alloc_inode, 98 .destroy_inode = minix_destroy_inode, 99 .read_inode = minix_read_inode, 100 .write_inode = minix_write_inode, 101 .delete_inode = minix_delete_inode, 102 .put_super = minix_put_super, 103 .statfs = minix_statfs, 104 .remount_fs = minix_remount, 105 }; 106 107 static int minix_remount (struct super_block * sb, int * flags, char * data) 108 { 109 struct minix_sb_info * sbi = minix_sb(sb); 110 struct minix_super_block * ms; 111 112 ms = sbi->s_ms; 113 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 114 return 0; 115 if (*flags & MS_RDONLY) { 116 if (ms->s_state & MINIX_VALID_FS || 117 !(sbi->s_mount_state & MINIX_VALID_FS)) 118 return 0; 119 /* Mounting a rw partition read-only. */ 120 if (sbi->s_version != MINIX_V3) 121 ms->s_state = sbi->s_mount_state; 122 mark_buffer_dirty(sbi->s_sbh); 123 } else { 124 /* Mount a partition which is read-only, read-write. */ 125 if (sbi->s_version != MINIX_V3) { 126 sbi->s_mount_state = ms->s_state; 127 ms->s_state &= ~MINIX_VALID_FS; 128 } else { 129 sbi->s_mount_state = MINIX_VALID_FS; 130 } 131 mark_buffer_dirty(sbi->s_sbh); 132 133 if (!(sbi->s_mount_state & MINIX_VALID_FS)) 134 printk("MINIX-fs warning: remounting unchecked fs, " 135 "running fsck is recommended\n"); 136 else if ((sbi->s_mount_state & MINIX_ERROR_FS)) 137 printk("MINIX-fs warning: remounting fs with errors, " 138 "running fsck is recommended\n"); 139 } 140 return 0; 141 } 142 143 static int minix_fill_super(struct super_block *s, void *data, int silent) 144 { 145 struct buffer_head *bh; 146 struct buffer_head **map; 147 struct minix_super_block *ms; 148 struct minix3_super_block *m3s = NULL; 149 unsigned long i, block; 150 struct inode *root_inode; 151 struct minix_sb_info *sbi; 152 153 sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL); 154 if (!sbi) 155 return -ENOMEM; 156 s->s_fs_info = sbi; 157 158 BUILD_BUG_ON(32 != sizeof (struct minix_inode)); 159 BUILD_BUG_ON(64 != sizeof(struct minix2_inode)); 160 161 if (!sb_set_blocksize(s, BLOCK_SIZE)) 162 goto out_bad_hblock; 163 164 if (!(bh = sb_bread(s, 1))) 165 goto out_bad_sb; 166 167 ms = (struct minix_super_block *) bh->b_data; 168 sbi->s_ms = ms; 169 sbi->s_sbh = bh; 170 sbi->s_mount_state = ms->s_state; 171 sbi->s_ninodes = ms->s_ninodes; 172 sbi->s_nzones = ms->s_nzones; 173 sbi->s_imap_blocks = ms->s_imap_blocks; 174 sbi->s_zmap_blocks = ms->s_zmap_blocks; 175 sbi->s_firstdatazone = ms->s_firstdatazone; 176 sbi->s_log_zone_size = ms->s_log_zone_size; 177 sbi->s_max_size = ms->s_max_size; 178 s->s_magic = ms->s_magic; 179 if (s->s_magic == MINIX_SUPER_MAGIC) { 180 sbi->s_version = MINIX_V1; 181 sbi->s_dirsize = 16; 182 sbi->s_namelen = 14; 183 sbi->s_link_max = MINIX_LINK_MAX; 184 } else if (s->s_magic == MINIX_SUPER_MAGIC2) { 185 sbi->s_version = MINIX_V1; 186 sbi->s_dirsize = 32; 187 sbi->s_namelen = 30; 188 sbi->s_link_max = MINIX_LINK_MAX; 189 } else if (s->s_magic == MINIX2_SUPER_MAGIC) { 190 sbi->s_version = MINIX_V2; 191 sbi->s_nzones = ms->s_zones; 192 sbi->s_dirsize = 16; 193 sbi->s_namelen = 14; 194 sbi->s_link_max = MINIX2_LINK_MAX; 195 } else if (s->s_magic == MINIX2_SUPER_MAGIC2) { 196 sbi->s_version = MINIX_V2; 197 sbi->s_nzones = ms->s_zones; 198 sbi->s_dirsize = 32; 199 sbi->s_namelen = 30; 200 sbi->s_link_max = MINIX2_LINK_MAX; 201 } else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) { 202 m3s = (struct minix3_super_block *) bh->b_data; 203 s->s_magic = m3s->s_magic; 204 sbi->s_imap_blocks = m3s->s_imap_blocks; 205 sbi->s_zmap_blocks = m3s->s_zmap_blocks; 206 sbi->s_firstdatazone = m3s->s_firstdatazone; 207 sbi->s_log_zone_size = m3s->s_log_zone_size; 208 sbi->s_max_size = m3s->s_max_size; 209 sbi->s_ninodes = m3s->s_ninodes; 210 sbi->s_nzones = m3s->s_zones; 211 sbi->s_dirsize = 64; 212 sbi->s_namelen = 60; 213 sbi->s_version = MINIX_V3; 214 sbi->s_link_max = MINIX2_LINK_MAX; 215 sbi->s_mount_state = MINIX_VALID_FS; 216 sb_set_blocksize(s, m3s->s_blocksize); 217 } else 218 goto out_no_fs; 219 220 /* 221 * Allocate the buffer map to keep the superblock small. 222 */ 223 if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0) 224 goto out_illegal_sb; 225 i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh); 226 map = kzalloc(i, GFP_KERNEL); 227 if (!map) 228 goto out_no_map; 229 sbi->s_imap = &map[0]; 230 sbi->s_zmap = &map[sbi->s_imap_blocks]; 231 232 block=2; 233 for (i=0 ; i < sbi->s_imap_blocks ; i++) { 234 if (!(sbi->s_imap[i]=sb_bread(s, block))) 235 goto out_no_bitmap; 236 block++; 237 } 238 for (i=0 ; i < sbi->s_zmap_blocks ; i++) { 239 if (!(sbi->s_zmap[i]=sb_bread(s, block))) 240 goto out_no_bitmap; 241 block++; 242 } 243 244 minix_set_bit(0,sbi->s_imap[0]->b_data); 245 minix_set_bit(0,sbi->s_zmap[0]->b_data); 246 247 /* set up enough so that it can read an inode */ 248 s->s_op = &minix_sops; 249 root_inode = iget(s, MINIX_ROOT_INO); 250 if (!root_inode || is_bad_inode(root_inode)) 251 goto out_no_root; 252 253 s->s_root = d_alloc_root(root_inode); 254 if (!s->s_root) 255 goto out_iput; 256 257 if (!NO_TRUNCATE) 258 s->s_root->d_op = &minix_dentry_operations; 259 260 if (!(s->s_flags & MS_RDONLY)) { 261 if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */ 262 ms->s_state &= ~MINIX_VALID_FS; 263 mark_buffer_dirty(bh); 264 } 265 if (!(sbi->s_mount_state & MINIX_VALID_FS)) 266 printk("MINIX-fs: mounting unchecked file system, " 267 "running fsck is recommended\n"); 268 else if (sbi->s_mount_state & MINIX_ERROR_FS) 269 printk("MINIX-fs: mounting file system with errors, " 270 "running fsck is recommended\n"); 271 return 0; 272 273 out_iput: 274 iput(root_inode); 275 goto out_freemap; 276 277 out_no_root: 278 if (!silent) 279 printk("MINIX-fs: get root inode failed\n"); 280 goto out_freemap; 281 282 out_no_bitmap: 283 printk("MINIX-fs: bad superblock or unable to read bitmaps\n"); 284 out_freemap: 285 for (i = 0; i < sbi->s_imap_blocks; i++) 286 brelse(sbi->s_imap[i]); 287 for (i = 0; i < sbi->s_zmap_blocks; i++) 288 brelse(sbi->s_zmap[i]); 289 kfree(sbi->s_imap); 290 goto out_release; 291 292 out_no_map: 293 if (!silent) 294 printk("MINIX-fs: can't allocate map\n"); 295 goto out_release; 296 297 out_illegal_sb: 298 if (!silent) 299 printk("MINIX-fs: bad superblock\n"); 300 goto out_release; 301 302 out_no_fs: 303 if (!silent) 304 printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 " 305 "on device %s.\n", s->s_id); 306 out_release: 307 brelse(bh); 308 goto out; 309 310 out_bad_hblock: 311 printk("MINIX-fs: blocksize too small for device\n"); 312 goto out; 313 314 out_bad_sb: 315 printk("MINIX-fs: unable to read superblock\n"); 316 out: 317 s->s_fs_info = NULL; 318 kfree(sbi); 319 return -EINVAL; 320 } 321 322 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf) 323 { 324 struct minix_sb_info *sbi = minix_sb(dentry->d_sb); 325 buf->f_type = dentry->d_sb->s_magic; 326 buf->f_bsize = dentry->d_sb->s_blocksize; 327 buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size; 328 buf->f_bfree = minix_count_free_blocks(sbi); 329 buf->f_bavail = buf->f_bfree; 330 buf->f_files = sbi->s_ninodes; 331 buf->f_ffree = minix_count_free_inodes(sbi); 332 buf->f_namelen = sbi->s_namelen; 333 return 0; 334 } 335 336 static int minix_get_block(struct inode *inode, sector_t block, 337 struct buffer_head *bh_result, int create) 338 { 339 if (INODE_VERSION(inode) == MINIX_V1) 340 return V1_minix_get_block(inode, block, bh_result, create); 341 else 342 return V2_minix_get_block(inode, block, bh_result, create); 343 } 344 345 static int minix_writepage(struct page *page, struct writeback_control *wbc) 346 { 347 return block_write_full_page(page, minix_get_block, wbc); 348 } 349 static int minix_readpage(struct file *file, struct page *page) 350 { 351 return block_read_full_page(page,minix_get_block); 352 } 353 static int minix_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) 354 { 355 return block_prepare_write(page,from,to,minix_get_block); 356 } 357 static sector_t minix_bmap(struct address_space *mapping, sector_t block) 358 { 359 return generic_block_bmap(mapping,block,minix_get_block); 360 } 361 static const struct address_space_operations minix_aops = { 362 .readpage = minix_readpage, 363 .writepage = minix_writepage, 364 .sync_page = block_sync_page, 365 .prepare_write = minix_prepare_write, 366 .commit_write = generic_commit_write, 367 .bmap = minix_bmap 368 }; 369 370 static const struct inode_operations minix_symlink_inode_operations = { 371 .readlink = generic_readlink, 372 .follow_link = page_follow_link_light, 373 .put_link = page_put_link, 374 .getattr = minix_getattr, 375 }; 376 377 void minix_set_inode(struct inode *inode, dev_t rdev) 378 { 379 if (S_ISREG(inode->i_mode)) { 380 inode->i_op = &minix_file_inode_operations; 381 inode->i_fop = &minix_file_operations; 382 inode->i_mapping->a_ops = &minix_aops; 383 } else if (S_ISDIR(inode->i_mode)) { 384 inode->i_op = &minix_dir_inode_operations; 385 inode->i_fop = &minix_dir_operations; 386 inode->i_mapping->a_ops = &minix_aops; 387 } else if (S_ISLNK(inode->i_mode)) { 388 inode->i_op = &minix_symlink_inode_operations; 389 inode->i_mapping->a_ops = &minix_aops; 390 } else 391 init_special_inode(inode, inode->i_mode, rdev); 392 } 393 394 /* 395 * The minix V1 function to read an inode. 396 */ 397 static void V1_minix_read_inode(struct inode * inode) 398 { 399 struct buffer_head * bh; 400 struct minix_inode * raw_inode; 401 struct minix_inode_info *minix_inode = minix_i(inode); 402 int i; 403 404 raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh); 405 if (!raw_inode) { 406 make_bad_inode(inode); 407 return; 408 } 409 inode->i_mode = raw_inode->i_mode; 410 inode->i_uid = (uid_t)raw_inode->i_uid; 411 inode->i_gid = (gid_t)raw_inode->i_gid; 412 inode->i_nlink = raw_inode->i_nlinks; 413 inode->i_size = raw_inode->i_size; 414 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time; 415 inode->i_mtime.tv_nsec = 0; 416 inode->i_atime.tv_nsec = 0; 417 inode->i_ctime.tv_nsec = 0; 418 inode->i_blocks = 0; 419 for (i = 0; i < 9; i++) 420 minix_inode->u.i1_data[i] = raw_inode->i_zone[i]; 421 minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0])); 422 brelse(bh); 423 } 424 425 /* 426 * The minix V2 function to read an inode. 427 */ 428 static void V2_minix_read_inode(struct inode * inode) 429 { 430 struct buffer_head * bh; 431 struct minix2_inode * raw_inode; 432 struct minix_inode_info *minix_inode = minix_i(inode); 433 int i; 434 435 raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh); 436 if (!raw_inode) { 437 make_bad_inode(inode); 438 return; 439 } 440 inode->i_mode = raw_inode->i_mode; 441 inode->i_uid = (uid_t)raw_inode->i_uid; 442 inode->i_gid = (gid_t)raw_inode->i_gid; 443 inode->i_nlink = raw_inode->i_nlinks; 444 inode->i_size = raw_inode->i_size; 445 inode->i_mtime.tv_sec = raw_inode->i_mtime; 446 inode->i_atime.tv_sec = raw_inode->i_atime; 447 inode->i_ctime.tv_sec = raw_inode->i_ctime; 448 inode->i_mtime.tv_nsec = 0; 449 inode->i_atime.tv_nsec = 0; 450 inode->i_ctime.tv_nsec = 0; 451 inode->i_blocks = 0; 452 for (i = 0; i < 10; i++) 453 minix_inode->u.i2_data[i] = raw_inode->i_zone[i]; 454 minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0])); 455 brelse(bh); 456 } 457 458 /* 459 * The global function to read an inode. 460 */ 461 static void minix_read_inode(struct inode * inode) 462 { 463 if (INODE_VERSION(inode) == MINIX_V1) 464 V1_minix_read_inode(inode); 465 else 466 V2_minix_read_inode(inode); 467 } 468 469 /* 470 * The minix V1 function to synchronize an inode. 471 */ 472 static struct buffer_head * V1_minix_update_inode(struct inode * inode) 473 { 474 struct buffer_head * bh; 475 struct minix_inode * raw_inode; 476 struct minix_inode_info *minix_inode = minix_i(inode); 477 int i; 478 479 raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh); 480 if (!raw_inode) 481 return NULL; 482 raw_inode->i_mode = inode->i_mode; 483 raw_inode->i_uid = fs_high2lowuid(inode->i_uid); 484 raw_inode->i_gid = fs_high2lowgid(inode->i_gid); 485 raw_inode->i_nlinks = inode->i_nlink; 486 raw_inode->i_size = inode->i_size; 487 raw_inode->i_time = inode->i_mtime.tv_sec; 488 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) 489 raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev); 490 else for (i = 0; i < 9; i++) 491 raw_inode->i_zone[i] = minix_inode->u.i1_data[i]; 492 mark_buffer_dirty(bh); 493 return bh; 494 } 495 496 /* 497 * The minix V2 function to synchronize an inode. 498 */ 499 static struct buffer_head * V2_minix_update_inode(struct inode * inode) 500 { 501 struct buffer_head * bh; 502 struct minix2_inode * raw_inode; 503 struct minix_inode_info *minix_inode = minix_i(inode); 504 int i; 505 506 raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh); 507 if (!raw_inode) 508 return NULL; 509 raw_inode->i_mode = inode->i_mode; 510 raw_inode->i_uid = fs_high2lowuid(inode->i_uid); 511 raw_inode->i_gid = fs_high2lowgid(inode->i_gid); 512 raw_inode->i_nlinks = inode->i_nlink; 513 raw_inode->i_size = inode->i_size; 514 raw_inode->i_mtime = inode->i_mtime.tv_sec; 515 raw_inode->i_atime = inode->i_atime.tv_sec; 516 raw_inode->i_ctime = inode->i_ctime.tv_sec; 517 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) 518 raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev); 519 else for (i = 0; i < 10; i++) 520 raw_inode->i_zone[i] = minix_inode->u.i2_data[i]; 521 mark_buffer_dirty(bh); 522 return bh; 523 } 524 525 static struct buffer_head *minix_update_inode(struct inode *inode) 526 { 527 if (INODE_VERSION(inode) == MINIX_V1) 528 return V1_minix_update_inode(inode); 529 else 530 return V2_minix_update_inode(inode); 531 } 532 533 static int minix_write_inode(struct inode * inode, int wait) 534 { 535 brelse(minix_update_inode(inode)); 536 return 0; 537 } 538 539 int minix_sync_inode(struct inode * inode) 540 { 541 int err = 0; 542 struct buffer_head *bh; 543 544 bh = minix_update_inode(inode); 545 if (bh && buffer_dirty(bh)) 546 { 547 sync_dirty_buffer(bh); 548 if (buffer_req(bh) && !buffer_uptodate(bh)) 549 { 550 printk("IO error syncing minix inode [%s:%08lx]\n", 551 inode->i_sb->s_id, inode->i_ino); 552 err = -1; 553 } 554 } 555 else if (!bh) 556 err = -1; 557 brelse (bh); 558 return err; 559 } 560 561 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) 562 { 563 struct inode *dir = dentry->d_parent->d_inode; 564 struct super_block *sb = dir->i_sb; 565 generic_fillattr(dentry->d_inode, stat); 566 if (INODE_VERSION(dentry->d_inode) == MINIX_V1) 567 stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb); 568 else 569 stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb); 570 stat->blksize = sb->s_blocksize; 571 return 0; 572 } 573 574 /* 575 * The function that is called for file truncation. 576 */ 577 void minix_truncate(struct inode * inode) 578 { 579 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) 580 return; 581 if (INODE_VERSION(inode) == MINIX_V1) 582 V1_minix_truncate(inode); 583 else 584 V2_minix_truncate(inode); 585 } 586 587 static int minix_get_sb(struct file_system_type *fs_type, 588 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 589 { 590 return get_sb_bdev(fs_type, flags, dev_name, data, minix_fill_super, 591 mnt); 592 } 593 594 static struct file_system_type minix_fs_type = { 595 .owner = THIS_MODULE, 596 .name = "minix", 597 .get_sb = minix_get_sb, 598 .kill_sb = kill_block_super, 599 .fs_flags = FS_REQUIRES_DEV, 600 }; 601 602 static int __init init_minix_fs(void) 603 { 604 int err = init_inodecache(); 605 if (err) 606 goto out1; 607 err = register_filesystem(&minix_fs_type); 608 if (err) 609 goto out; 610 return 0; 611 out: 612 destroy_inodecache(); 613 out1: 614 return err; 615 } 616 617 static void __exit exit_minix_fs(void) 618 { 619 unregister_filesystem(&minix_fs_type); 620 destroy_inodecache(); 621 } 622 623 module_init(init_minix_fs) 624 module_exit(exit_minix_fs) 625 MODULE_LICENSE("GPL"); 626 627