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 (!strncmp(rootdir->di_fname, QNX4_BMNAME, sizeof QNX4_BMNAME)) { 205 found = 1; 206 qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL ); 207 if (!qnx4_sb(sb)->BitMap) { 208 brelse (bh); 209 return "not enough memory for bitmap inode"; 210 } 211 memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) ); /* keep bitmap inode known */ 212 break; 213 } 214 } 215 } 216 brelse(bh); 217 if (found != 0) { 218 break; 219 } 220 } 221 if (found == 0) { 222 return "bitmap file not found."; 223 } 224 } 225 return NULL; 226 } 227 228 static int qnx4_fill_super(struct super_block *s, void *data, int silent) 229 { 230 struct buffer_head *bh; 231 struct inode *root; 232 const char *errmsg; 233 struct qnx4_sb_info *qs; 234 int ret = -EINVAL; 235 236 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL); 237 if (!qs) 238 return -ENOMEM; 239 s->s_fs_info = qs; 240 241 sb_set_blocksize(s, QNX4_BLOCK_SIZE); 242 243 /* Check the superblock signature. Since the qnx4 code is 244 dangerous, we should leave as quickly as possible 245 if we don't belong here... */ 246 bh = sb_bread(s, 1); 247 if (!bh) { 248 printk(KERN_ERR "qnx4: unable to read the superblock\n"); 249 goto outnobh; 250 } 251 if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) { 252 if (!silent) 253 printk(KERN_ERR "qnx4: wrong fsid in superblock.\n"); 254 goto out; 255 } 256 s->s_op = &qnx4_sops; 257 s->s_magic = QNX4_SUPER_MAGIC; 258 s->s_flags |= MS_RDONLY; /* Yup, read-only yet */ 259 qnx4_sb(s)->sb_buf = bh; 260 qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data; 261 262 263 /* check before allocating dentries, inodes, .. */ 264 errmsg = qnx4_checkroot(s); 265 if (errmsg != NULL) { 266 if (!silent) 267 printk(KERN_ERR "qnx4: %s\n", errmsg); 268 goto out; 269 } 270 271 /* does root not have inode number QNX4_ROOT_INO ?? */ 272 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK); 273 if (IS_ERR(root)) { 274 printk(KERN_ERR "qnx4: get inode failed\n"); 275 ret = PTR_ERR(root); 276 goto out; 277 } 278 279 ret = -ENOMEM; 280 s->s_root = d_alloc_root(root); 281 if (s->s_root == NULL) 282 goto outi; 283 284 brelse(bh); 285 286 return 0; 287 288 outi: 289 iput(root); 290 out: 291 brelse(bh); 292 outnobh: 293 kfree(qs); 294 s->s_fs_info = NULL; 295 return ret; 296 } 297 298 static void qnx4_put_super(struct super_block *sb) 299 { 300 struct qnx4_sb_info *qs = qnx4_sb(sb); 301 kfree( qs->BitMap ); 302 kfree( qs ); 303 sb->s_fs_info = NULL; 304 return; 305 } 306 307 static int qnx4_writepage(struct page *page, struct writeback_control *wbc) 308 { 309 return block_write_full_page(page,qnx4_get_block, wbc); 310 } 311 312 static int qnx4_readpage(struct file *file, struct page *page) 313 { 314 return block_read_full_page(page,qnx4_get_block); 315 } 316 317 static int qnx4_write_begin(struct file *file, struct address_space *mapping, 318 loff_t pos, unsigned len, unsigned flags, 319 struct page **pagep, void **fsdata) 320 { 321 struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host); 322 *pagep = NULL; 323 return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 324 qnx4_get_block, 325 &qnx4_inode->mmu_private); 326 } 327 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block) 328 { 329 return generic_block_bmap(mapping,block,qnx4_get_block); 330 } 331 static const struct address_space_operations qnx4_aops = { 332 .readpage = qnx4_readpage, 333 .writepage = qnx4_writepage, 334 .sync_page = block_sync_page, 335 .write_begin = qnx4_write_begin, 336 .write_end = generic_write_end, 337 .bmap = qnx4_bmap 338 }; 339 340 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino) 341 { 342 struct buffer_head *bh; 343 struct qnx4_inode_entry *raw_inode; 344 int block; 345 struct qnx4_inode_entry *qnx4_inode; 346 struct inode *inode; 347 348 inode = iget_locked(sb, ino); 349 if (!inode) 350 return ERR_PTR(-ENOMEM); 351 if (!(inode->i_state & I_NEW)) 352 return inode; 353 354 qnx4_inode = qnx4_raw_inode(inode); 355 inode->i_mode = 0; 356 357 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino)); 358 if (!ino) { 359 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is " 360 "out of range\n", 361 sb->s_id, ino); 362 iget_failed(inode); 363 return ERR_PTR(-EIO); 364 } 365 block = ino / QNX4_INODES_PER_BLOCK; 366 367 if (!(bh = sb_bread(sb, block))) { 368 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev " 369 "%s\n", sb->s_id); 370 iget_failed(inode); 371 return ERR_PTR(-EIO); 372 } 373 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) + 374 (ino % QNX4_INODES_PER_BLOCK); 375 376 inode->i_mode = le16_to_cpu(raw_inode->di_mode); 377 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid); 378 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid); 379 inode->i_nlink = le16_to_cpu(raw_inode->di_nlink); 380 inode->i_size = le32_to_cpu(raw_inode->di_size); 381 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime); 382 inode->i_mtime.tv_nsec = 0; 383 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime); 384 inode->i_atime.tv_nsec = 0; 385 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime); 386 inode->i_ctime.tv_nsec = 0; 387 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size); 388 389 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE); 390 if (S_ISREG(inode->i_mode)) { 391 inode->i_fop = &generic_ro_fops; 392 inode->i_mapping->a_ops = &qnx4_aops; 393 qnx4_i(inode)->mmu_private = inode->i_size; 394 } else if (S_ISDIR(inode->i_mode)) { 395 inode->i_op = &qnx4_dir_inode_operations; 396 inode->i_fop = &qnx4_dir_operations; 397 } else if (S_ISLNK(inode->i_mode)) { 398 inode->i_op = &page_symlink_inode_operations; 399 inode->i_mapping->a_ops = &qnx4_aops; 400 qnx4_i(inode)->mmu_private = inode->i_size; 401 } else { 402 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n", 403 ino, sb->s_id); 404 iget_failed(inode); 405 brelse(bh); 406 return ERR_PTR(-EIO); 407 } 408 brelse(bh); 409 unlock_new_inode(inode); 410 return inode; 411 } 412 413 static struct kmem_cache *qnx4_inode_cachep; 414 415 static struct inode *qnx4_alloc_inode(struct super_block *sb) 416 { 417 struct qnx4_inode_info *ei; 418 ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL); 419 if (!ei) 420 return NULL; 421 return &ei->vfs_inode; 422 } 423 424 static void qnx4_destroy_inode(struct inode *inode) 425 { 426 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode)); 427 } 428 429 static void init_once(void *foo) 430 { 431 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo; 432 433 inode_init_once(&ei->vfs_inode); 434 } 435 436 static int init_inodecache(void) 437 { 438 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache", 439 sizeof(struct qnx4_inode_info), 440 0, (SLAB_RECLAIM_ACCOUNT| 441 SLAB_MEM_SPREAD), 442 init_once); 443 if (qnx4_inode_cachep == NULL) 444 return -ENOMEM; 445 return 0; 446 } 447 448 static void destroy_inodecache(void) 449 { 450 kmem_cache_destroy(qnx4_inode_cachep); 451 } 452 453 static int qnx4_get_sb(struct file_system_type *fs_type, 454 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 455 { 456 return get_sb_bdev(fs_type, flags, dev_name, data, qnx4_fill_super, 457 mnt); 458 } 459 460 static struct file_system_type qnx4_fs_type = { 461 .owner = THIS_MODULE, 462 .name = "qnx4", 463 .get_sb = qnx4_get_sb, 464 .kill_sb = kill_block_super, 465 .fs_flags = FS_REQUIRES_DEV, 466 }; 467 468 static int __init init_qnx4_fs(void) 469 { 470 int err; 471 472 err = init_inodecache(); 473 if (err) 474 return err; 475 476 err = register_filesystem(&qnx4_fs_type); 477 if (err) { 478 destroy_inodecache(); 479 return err; 480 } 481 482 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n"); 483 return 0; 484 } 485 486 static void __exit exit_qnx4_fs(void) 487 { 488 unregister_filesystem(&qnx4_fs_type); 489 destroy_inodecache(); 490 } 491 492 module_init(init_qnx4_fs) 493 module_exit(exit_qnx4_fs) 494 MODULE_LICENSE("GPL"); 495 496