1 /* 2 * QNX4 file system, Linux implementation. 3 * 4 * Version : 0.2.1 5 * 6 * Using parts of the xiafs filesystem. 7 * 8 * History : 9 * 10 * 01-06-1998 by Richard Frowijn : first release. 11 * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc. 12 * 30-06-1998 by Frank Denis : first step to write inodes. 13 */ 14 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/slab.h> 18 #include <linux/highuid.h> 19 #include <linux/smp_lock.h> 20 #include <linux/pagemap.h> 21 #include <linux/buffer_head.h> 22 #include <linux/writeback.h> 23 #include <linux/statfs.h> 24 #include "qnx4.h" 25 26 #define QNX4_VERSION 4 27 #define QNX4_BMNAME ".bitmap" 28 29 static const struct super_operations qnx4_sops; 30 31 static void qnx4_put_super(struct super_block *sb); 32 static struct inode *qnx4_alloc_inode(struct super_block *sb); 33 static void qnx4_destroy_inode(struct inode *inode); 34 static int qnx4_remount(struct super_block *sb, int *flags, char *data); 35 static int qnx4_statfs(struct dentry *, struct kstatfs *); 36 37 static const struct super_operations qnx4_sops = 38 { 39 .alloc_inode = qnx4_alloc_inode, 40 .destroy_inode = qnx4_destroy_inode, 41 .put_super = qnx4_put_super, 42 .statfs = qnx4_statfs, 43 .remount_fs = qnx4_remount, 44 }; 45 46 static int qnx4_remount(struct super_block *sb, int *flags, char *data) 47 { 48 struct qnx4_sb_info *qs; 49 50 qs = qnx4_sb(sb); 51 qs->Version = QNX4_VERSION; 52 *flags |= MS_RDONLY; 53 return 0; 54 } 55 56 static struct buffer_head *qnx4_getblk(struct inode *inode, int nr, 57 int create) 58 { 59 struct buffer_head *result = NULL; 60 61 if ( nr >= 0 ) 62 nr = qnx4_block_map( inode, nr ); 63 if (nr) { 64 result = sb_getblk(inode->i_sb, nr); 65 return result; 66 } 67 return NULL; 68 } 69 70 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create) 71 { 72 struct buffer_head *bh; 73 74 bh = qnx4_getblk(inode, block, create); 75 if (!bh || buffer_uptodate(bh)) { 76 return bh; 77 } 78 ll_rw_block(READ, 1, &bh); 79 wait_on_buffer(bh); 80 if (buffer_uptodate(bh)) { 81 return bh; 82 } 83 brelse(bh); 84 85 return NULL; 86 } 87 88 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create ) 89 { 90 unsigned long phys; 91 92 QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock)); 93 94 phys = qnx4_block_map( inode, iblock ); 95 if ( phys ) { 96 // logical block is before EOF 97 map_bh(bh, inode->i_sb, phys); 98 } 99 return 0; 100 } 101 102 unsigned long qnx4_block_map( struct inode *inode, long iblock ) 103 { 104 int ix; 105 long offset, i_xblk; 106 unsigned long block = 0; 107 struct buffer_head *bh = NULL; 108 struct qnx4_xblk *xblk = NULL; 109 struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode); 110 u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts); 111 112 if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) { 113 // iblock is in the first extent. This is easy. 114 block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1; 115 } else { 116 // iblock is beyond first extent. We have to follow the extent chain. 117 i_xblk = le32_to_cpu(qnx4_inode->di_xblk); 118 offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size); 119 ix = 0; 120 while ( --nxtnt > 0 ) { 121 if ( ix == 0 ) { 122 // read next xtnt block. 123 bh = sb_bread(inode->i_sb, i_xblk - 1); 124 if ( !bh ) { 125 QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1)); 126 return -EIO; 127 } 128 xblk = (struct qnx4_xblk*)bh->b_data; 129 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) { 130 QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk)); 131 return -EIO; 132 } 133 } 134 if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) { 135 // got it! 136 block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1; 137 break; 138 } 139 offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size); 140 if ( ++ix >= xblk->xblk_num_xtnts ) { 141 i_xblk = le32_to_cpu(xblk->xblk_next_xblk); 142 ix = 0; 143 brelse( bh ); 144 bh = NULL; 145 } 146 } 147 if ( bh ) 148 brelse( bh ); 149 } 150 151 QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block)); 152 return block; 153 } 154 155 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf) 156 { 157 struct super_block *sb = dentry->d_sb; 158 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 159 160 lock_kernel(); 161 162 buf->f_type = sb->s_magic; 163 buf->f_bsize = sb->s_blocksize; 164 buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8; 165 buf->f_bfree = qnx4_count_free_blocks(sb); 166 buf->f_bavail = buf->f_bfree; 167 buf->f_namelen = QNX4_NAME_MAX; 168 buf->f_fsid.val[0] = (u32)id; 169 buf->f_fsid.val[1] = (u32)(id >> 32); 170 171 unlock_kernel(); 172 173 return 0; 174 } 175 176 /* 177 * Check the root directory of the filesystem to make sure 178 * it really _is_ a qnx4 filesystem, and to check the size 179 * of the directory entry. 180 */ 181 static const char *qnx4_checkroot(struct super_block *sb) 182 { 183 struct buffer_head *bh; 184 struct qnx4_inode_entry *rootdir; 185 int rd, rl; 186 int i, j; 187 int found = 0; 188 189 if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') { 190 return "no qnx4 filesystem (no root dir)."; 191 } else { 192 QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id)); 193 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1; 194 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size); 195 for (j = 0; j < rl; j++) { 196 bh = sb_bread(sb, rd + j); /* root dir, first block */ 197 if (bh == NULL) { 198 return "unable to read root entry."; 199 } 200 for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) { 201 rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE); 202 if (rootdir->di_fname != NULL) { 203 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname)); 204 if (!strcmp(rootdir->di_fname, 205 QNX4_BMNAME)) { 206 found = 1; 207 qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL ); 208 if (!qnx4_sb(sb)->BitMap) { 209 brelse (bh); 210 return "not enough memory for bitmap inode"; 211 } 212 memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) ); /* keep bitmap inode known */ 213 break; 214 } 215 } 216 } 217 brelse(bh); 218 if (found != 0) { 219 break; 220 } 221 } 222 if (found == 0) { 223 return "bitmap file not found."; 224 } 225 } 226 return NULL; 227 } 228 229 static int qnx4_fill_super(struct super_block *s, void *data, int silent) 230 { 231 struct buffer_head *bh; 232 struct inode *root; 233 const char *errmsg; 234 struct qnx4_sb_info *qs; 235 int ret = -EINVAL; 236 237 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL); 238 if (!qs) 239 return -ENOMEM; 240 s->s_fs_info = qs; 241 242 sb_set_blocksize(s, QNX4_BLOCK_SIZE); 243 244 /* Check the superblock signature. Since the qnx4 code is 245 dangerous, we should leave as quickly as possible 246 if we don't belong here... */ 247 bh = sb_bread(s, 1); 248 if (!bh) { 249 printk(KERN_ERR "qnx4: unable to read the superblock\n"); 250 goto outnobh; 251 } 252 if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) { 253 if (!silent) 254 printk(KERN_ERR "qnx4: wrong fsid in superblock.\n"); 255 goto out; 256 } 257 s->s_op = &qnx4_sops; 258 s->s_magic = QNX4_SUPER_MAGIC; 259 s->s_flags |= MS_RDONLY; /* Yup, read-only yet */ 260 qnx4_sb(s)->sb_buf = bh; 261 qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data; 262 263 264 /* check before allocating dentries, inodes, .. */ 265 errmsg = qnx4_checkroot(s); 266 if (errmsg != NULL) { 267 if (!silent) 268 printk(KERN_ERR "qnx4: %s\n", errmsg); 269 goto out; 270 } 271 272 /* does root not have inode number QNX4_ROOT_INO ?? */ 273 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK); 274 if (IS_ERR(root)) { 275 printk(KERN_ERR "qnx4: get inode failed\n"); 276 ret = PTR_ERR(root); 277 goto out; 278 } 279 280 ret = -ENOMEM; 281 s->s_root = d_alloc_root(root); 282 if (s->s_root == NULL) 283 goto outi; 284 285 brelse(bh); 286 287 return 0; 288 289 outi: 290 iput(root); 291 out: 292 brelse(bh); 293 outnobh: 294 kfree(qs); 295 s->s_fs_info = NULL; 296 return ret; 297 } 298 299 static void qnx4_put_super(struct super_block *sb) 300 { 301 struct qnx4_sb_info *qs = qnx4_sb(sb); 302 kfree( qs->BitMap ); 303 kfree( qs ); 304 sb->s_fs_info = NULL; 305 return; 306 } 307 308 static int qnx4_writepage(struct page *page, struct writeback_control *wbc) 309 { 310 return block_write_full_page(page,qnx4_get_block, wbc); 311 } 312 313 static int qnx4_readpage(struct file *file, struct page *page) 314 { 315 return block_read_full_page(page,qnx4_get_block); 316 } 317 318 static int qnx4_write_begin(struct file *file, struct address_space *mapping, 319 loff_t pos, unsigned len, unsigned flags, 320 struct page **pagep, void **fsdata) 321 { 322 struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host); 323 *pagep = NULL; 324 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 325 qnx4_get_block, 326 &qnx4_inode->mmu_private); 327 } 328 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block) 329 { 330 return generic_block_bmap(mapping,block,qnx4_get_block); 331 } 332 static const struct address_space_operations qnx4_aops = { 333 .readpage = qnx4_readpage, 334 .writepage = qnx4_writepage, 335 .sync_page = block_sync_page, 336 .write_begin = qnx4_write_begin, 337 .write_end = generic_write_end, 338 .bmap = qnx4_bmap 339 }; 340 341 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino) 342 { 343 struct buffer_head *bh; 344 struct qnx4_inode_entry *raw_inode; 345 int block; 346 struct qnx4_inode_entry *qnx4_inode; 347 struct inode *inode; 348 349 inode = iget_locked(sb, ino); 350 if (!inode) 351 return ERR_PTR(-ENOMEM); 352 if (!(inode->i_state & I_NEW)) 353 return inode; 354 355 qnx4_inode = qnx4_raw_inode(inode); 356 inode->i_mode = 0; 357 358 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino)); 359 if (!ino) { 360 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is " 361 "out of range\n", 362 sb->s_id, ino); 363 iget_failed(inode); 364 return ERR_PTR(-EIO); 365 } 366 block = ino / QNX4_INODES_PER_BLOCK; 367 368 if (!(bh = sb_bread(sb, block))) { 369 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev " 370 "%s\n", sb->s_id); 371 iget_failed(inode); 372 return ERR_PTR(-EIO); 373 } 374 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) + 375 (ino % QNX4_INODES_PER_BLOCK); 376 377 inode->i_mode = le16_to_cpu(raw_inode->di_mode); 378 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid); 379 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid); 380 inode->i_nlink = le16_to_cpu(raw_inode->di_nlink); 381 inode->i_size = le32_to_cpu(raw_inode->di_size); 382 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime); 383 inode->i_mtime.tv_nsec = 0; 384 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime); 385 inode->i_atime.tv_nsec = 0; 386 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime); 387 inode->i_ctime.tv_nsec = 0; 388 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size); 389 390 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE); 391 if (S_ISREG(inode->i_mode)) { 392 inode->i_fop = &generic_ro_fops; 393 inode->i_mapping->a_ops = &qnx4_aops; 394 qnx4_i(inode)->mmu_private = inode->i_size; 395 } else if (S_ISDIR(inode->i_mode)) { 396 inode->i_op = &qnx4_dir_inode_operations; 397 inode->i_fop = &qnx4_dir_operations; 398 } else if (S_ISLNK(inode->i_mode)) { 399 inode->i_op = &page_symlink_inode_operations; 400 inode->i_mapping->a_ops = &qnx4_aops; 401 qnx4_i(inode)->mmu_private = inode->i_size; 402 } else { 403 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n", 404 ino, sb->s_id); 405 iget_failed(inode); 406 brelse(bh); 407 return ERR_PTR(-EIO); 408 } 409 brelse(bh); 410 unlock_new_inode(inode); 411 return inode; 412 } 413 414 static struct kmem_cache *qnx4_inode_cachep; 415 416 static struct inode *qnx4_alloc_inode(struct super_block *sb) 417 { 418 struct qnx4_inode_info *ei; 419 ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL); 420 if (!ei) 421 return NULL; 422 return &ei->vfs_inode; 423 } 424 425 static void qnx4_destroy_inode(struct inode *inode) 426 { 427 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode)); 428 } 429 430 static void init_once(void *foo) 431 { 432 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo; 433 434 inode_init_once(&ei->vfs_inode); 435 } 436 437 static int init_inodecache(void) 438 { 439 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache", 440 sizeof(struct qnx4_inode_info), 441 0, (SLAB_RECLAIM_ACCOUNT| 442 SLAB_MEM_SPREAD), 443 init_once); 444 if (qnx4_inode_cachep == NULL) 445 return -ENOMEM; 446 return 0; 447 } 448 449 static void destroy_inodecache(void) 450 { 451 kmem_cache_destroy(qnx4_inode_cachep); 452 } 453 454 static int qnx4_get_sb(struct file_system_type *fs_type, 455 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 456 { 457 return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super, 458 mnt); 459 } 460 461 static struct file_system_type qnx4_fs_type = { 462 .owner = THIS_MODULE, 463 .name = "qnx4", 464 .get_sb = qnx4_get_sb, 465 .kill_sb = kill_block_super, 466 .fs_flags = FS_REQUIRES_DEV, 467 }; 468 469 static int __init init_qnx4_fs(void) 470 { 471 int err; 472 473 err = init_inodecache(); 474 if (err) 475 return err; 476 477 err = register_filesystem(&qnx4_fs_type); 478 if (err) { 479 destroy_inodecache(); 480 return err; 481 } 482 483 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n"); 484 return 0; 485 } 486 487 static void __exit exit_qnx4_fs(void) 488 { 489 unregister_filesystem(&qnx4_fs_type); 490 destroy_inodecache(); 491 } 492 493 module_init(init_qnx4_fs) 494 module_exit(exit_qnx4_fs) 495 MODULE_LICENSE("GPL"); 496 497