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/pagemap.h> 20 #include <linux/buffer_head.h> 21 #include <linux/writeback.h> 22 #include <linux/statfs.h> 23 #include "qnx4.h" 24 25 #define QNX4_VERSION 4 26 #define QNX4_BMNAME ".bitmap" 27 28 static const struct super_operations qnx4_sops; 29 30 static void qnx4_put_super(struct super_block *sb); 31 static struct inode *qnx4_alloc_inode(struct super_block *sb); 32 static void qnx4_destroy_inode(struct inode *inode); 33 static int qnx4_remount(struct super_block *sb, int *flags, char *data); 34 static int qnx4_statfs(struct dentry *, struct kstatfs *); 35 36 static const struct super_operations qnx4_sops = 37 { 38 .alloc_inode = qnx4_alloc_inode, 39 .destroy_inode = qnx4_destroy_inode, 40 .put_super = qnx4_put_super, 41 .statfs = qnx4_statfs, 42 .remount_fs = qnx4_remount, 43 }; 44 45 static int qnx4_remount(struct super_block *sb, int *flags, char *data) 46 { 47 struct qnx4_sb_info *qs; 48 49 qs = qnx4_sb(sb); 50 qs->Version = QNX4_VERSION; 51 *flags |= MS_RDONLY; 52 return 0; 53 } 54 55 static struct buffer_head *qnx4_getblk(struct inode *inode, int nr, 56 int create) 57 { 58 struct buffer_head *result = NULL; 59 60 if ( nr >= 0 ) 61 nr = qnx4_block_map( inode, nr ); 62 if (nr) { 63 result = sb_getblk(inode->i_sb, nr); 64 return result; 65 } 66 return NULL; 67 } 68 69 struct buffer_head *qnx4_bread(struct inode *inode, int block, int create) 70 { 71 struct buffer_head *bh; 72 73 bh = qnx4_getblk(inode, block, create); 74 if (!bh || buffer_uptodate(bh)) { 75 return bh; 76 } 77 ll_rw_block(READ, 1, &bh); 78 wait_on_buffer(bh); 79 if (buffer_uptodate(bh)) { 80 return bh; 81 } 82 brelse(bh); 83 84 return NULL; 85 } 86 87 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create ) 88 { 89 unsigned long phys; 90 91 QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock)); 92 93 phys = qnx4_block_map( inode, iblock ); 94 if ( phys ) { 95 // logical block is before EOF 96 map_bh(bh, inode->i_sb, phys); 97 } 98 return 0; 99 } 100 101 unsigned long qnx4_block_map( struct inode *inode, long iblock ) 102 { 103 int ix; 104 long offset, i_xblk; 105 unsigned long block = 0; 106 struct buffer_head *bh = NULL; 107 struct qnx4_xblk *xblk = NULL; 108 struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode); 109 u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts); 110 111 if ( iblock < le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size) ) { 112 // iblock is in the first extent. This is easy. 113 block = le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_blk) + iblock - 1; 114 } else { 115 // iblock is beyond first extent. We have to follow the extent chain. 116 i_xblk = le32_to_cpu(qnx4_inode->di_xblk); 117 offset = iblock - le32_to_cpu(qnx4_inode->di_first_xtnt.xtnt_size); 118 ix = 0; 119 while ( --nxtnt > 0 ) { 120 if ( ix == 0 ) { 121 // read next xtnt block. 122 bh = sb_bread(inode->i_sb, i_xblk - 1); 123 if ( !bh ) { 124 QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1)); 125 return -EIO; 126 } 127 xblk = (struct qnx4_xblk*)bh->b_data; 128 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) { 129 QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk)); 130 return -EIO; 131 } 132 } 133 if ( offset < le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size) ) { 134 // got it! 135 block = le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_blk) + offset - 1; 136 break; 137 } 138 offset -= le32_to_cpu(xblk->xblk_xtnts[ix].xtnt_size); 139 if ( ++ix >= xblk->xblk_num_xtnts ) { 140 i_xblk = le32_to_cpu(xblk->xblk_next_xblk); 141 ix = 0; 142 brelse( bh ); 143 bh = NULL; 144 } 145 } 146 if ( bh ) 147 brelse( bh ); 148 } 149 150 QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block)); 151 return block; 152 } 153 154 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf) 155 { 156 struct super_block *sb = dentry->d_sb; 157 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 158 159 buf->f_type = sb->s_magic; 160 buf->f_bsize = sb->s_blocksize; 161 buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8; 162 buf->f_bfree = qnx4_count_free_blocks(sb); 163 buf->f_bavail = buf->f_bfree; 164 buf->f_namelen = QNX4_NAME_MAX; 165 buf->f_fsid.val[0] = (u32)id; 166 buf->f_fsid.val[1] = (u32)(id >> 32); 167 168 return 0; 169 } 170 171 /* 172 * Check the root directory of the filesystem to make sure 173 * it really _is_ a qnx4 filesystem, and to check the size 174 * of the directory entry. 175 */ 176 static const char *qnx4_checkroot(struct super_block *sb) 177 { 178 struct buffer_head *bh; 179 struct qnx4_inode_entry *rootdir; 180 int rd, rl; 181 int i, j; 182 int found = 0; 183 184 if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') { 185 return "no qnx4 filesystem (no root dir)."; 186 } else { 187 QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id)); 188 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1; 189 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size); 190 for (j = 0; j < rl; j++) { 191 bh = sb_bread(sb, rd + j); /* root dir, first block */ 192 if (bh == NULL) { 193 return "unable to read root entry."; 194 } 195 for (i = 0; i < QNX4_INODES_PER_BLOCK; i++) { 196 rootdir = (struct qnx4_inode_entry *) (bh->b_data + i * QNX4_DIR_ENTRY_SIZE); 197 if (rootdir->di_fname != NULL) { 198 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname)); 199 if (!strcmp(rootdir->di_fname, 200 QNX4_BMNAME)) { 201 found = 1; 202 qnx4_sb(sb)->BitMap = kmalloc( sizeof( struct qnx4_inode_entry ), GFP_KERNEL ); 203 if (!qnx4_sb(sb)->BitMap) { 204 brelse (bh); 205 return "not enough memory for bitmap inode"; 206 } 207 memcpy( qnx4_sb(sb)->BitMap, rootdir, sizeof( struct qnx4_inode_entry ) ); /* keep bitmap inode known */ 208 break; 209 } 210 } 211 } 212 brelse(bh); 213 if (found != 0) { 214 break; 215 } 216 } 217 if (found == 0) { 218 return "bitmap file not found."; 219 } 220 } 221 return NULL; 222 } 223 224 static int qnx4_fill_super(struct super_block *s, void *data, int silent) 225 { 226 struct buffer_head *bh; 227 struct inode *root; 228 const char *errmsg; 229 struct qnx4_sb_info *qs; 230 int ret = -EINVAL; 231 232 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL); 233 if (!qs) 234 return -ENOMEM; 235 s->s_fs_info = qs; 236 237 sb_set_blocksize(s, QNX4_BLOCK_SIZE); 238 239 /* Check the superblock signature. Since the qnx4 code is 240 dangerous, we should leave as quickly as possible 241 if we don't belong here... */ 242 bh = sb_bread(s, 1); 243 if (!bh) { 244 printk(KERN_ERR "qnx4: unable to read the superblock\n"); 245 goto outnobh; 246 } 247 if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) { 248 if (!silent) 249 printk(KERN_ERR "qnx4: wrong fsid in superblock.\n"); 250 goto out; 251 } 252 s->s_op = &qnx4_sops; 253 s->s_magic = QNX4_SUPER_MAGIC; 254 s->s_flags |= MS_RDONLY; /* Yup, read-only yet */ 255 qnx4_sb(s)->sb_buf = bh; 256 qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data; 257 258 259 /* check before allocating dentries, inodes, .. */ 260 errmsg = qnx4_checkroot(s); 261 if (errmsg != NULL) { 262 if (!silent) 263 printk(KERN_ERR "qnx4: %s\n", errmsg); 264 goto out; 265 } 266 267 /* does root not have inode number QNX4_ROOT_INO ?? */ 268 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK); 269 if (IS_ERR(root)) { 270 printk(KERN_ERR "qnx4: get inode failed\n"); 271 ret = PTR_ERR(root); 272 goto out; 273 } 274 275 ret = -ENOMEM; 276 s->s_root = d_alloc_root(root); 277 if (s->s_root == NULL) 278 goto outi; 279 280 brelse(bh); 281 return 0; 282 283 outi: 284 iput(root); 285 out: 286 brelse(bh); 287 outnobh: 288 kfree(qs); 289 s->s_fs_info = NULL; 290 return ret; 291 } 292 293 static void qnx4_put_super(struct super_block *sb) 294 { 295 struct qnx4_sb_info *qs = qnx4_sb(sb); 296 kfree( qs->BitMap ); 297 kfree( qs ); 298 sb->s_fs_info = NULL; 299 return; 300 } 301 302 static int qnx4_writepage(struct page *page, struct writeback_control *wbc) 303 { 304 return block_write_full_page(page,qnx4_get_block, wbc); 305 } 306 307 static int qnx4_readpage(struct file *file, struct page *page) 308 { 309 return block_read_full_page(page,qnx4_get_block); 310 } 311 312 static int qnx4_write_begin(struct file *file, struct address_space *mapping, 313 loff_t pos, unsigned len, unsigned flags, 314 struct page **pagep, void **fsdata) 315 { 316 struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host); 317 int ret; 318 319 *pagep = NULL; 320 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 321 qnx4_get_block, 322 &qnx4_inode->mmu_private); 323 if (unlikely(ret)) { 324 loff_t isize = mapping->host->i_size; 325 if (pos + len > isize) 326 vmtruncate(mapping->host, isize); 327 } 328 329 return ret; 330 } 331 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block) 332 { 333 return generic_block_bmap(mapping,block,qnx4_get_block); 334 } 335 static const struct address_space_operations qnx4_aops = { 336 .readpage = qnx4_readpage, 337 .writepage = qnx4_writepage, 338 .sync_page = block_sync_page, 339 .write_begin = qnx4_write_begin, 340 .write_end = generic_write_end, 341 .bmap = qnx4_bmap 342 }; 343 344 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino) 345 { 346 struct buffer_head *bh; 347 struct qnx4_inode_entry *raw_inode; 348 int block; 349 struct qnx4_inode_entry *qnx4_inode; 350 struct inode *inode; 351 352 inode = iget_locked(sb, ino); 353 if (!inode) 354 return ERR_PTR(-ENOMEM); 355 if (!(inode->i_state & I_NEW)) 356 return inode; 357 358 qnx4_inode = qnx4_raw_inode(inode); 359 inode->i_mode = 0; 360 361 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino)); 362 if (!ino) { 363 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is " 364 "out of range\n", 365 sb->s_id, ino); 366 iget_failed(inode); 367 return ERR_PTR(-EIO); 368 } 369 block = ino / QNX4_INODES_PER_BLOCK; 370 371 if (!(bh = sb_bread(sb, block))) { 372 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev " 373 "%s\n", sb->s_id); 374 iget_failed(inode); 375 return ERR_PTR(-EIO); 376 } 377 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) + 378 (ino % QNX4_INODES_PER_BLOCK); 379 380 inode->i_mode = le16_to_cpu(raw_inode->di_mode); 381 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid); 382 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid); 383 inode->i_nlink = le16_to_cpu(raw_inode->di_nlink); 384 inode->i_size = le32_to_cpu(raw_inode->di_size); 385 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime); 386 inode->i_mtime.tv_nsec = 0; 387 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime); 388 inode->i_atime.tv_nsec = 0; 389 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime); 390 inode->i_ctime.tv_nsec = 0; 391 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size); 392 393 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE); 394 if (S_ISREG(inode->i_mode)) { 395 inode->i_fop = &generic_ro_fops; 396 inode->i_mapping->a_ops = &qnx4_aops; 397 qnx4_i(inode)->mmu_private = inode->i_size; 398 } else if (S_ISDIR(inode->i_mode)) { 399 inode->i_op = &qnx4_dir_inode_operations; 400 inode->i_fop = &qnx4_dir_operations; 401 } else if (S_ISLNK(inode->i_mode)) { 402 inode->i_op = &page_symlink_inode_operations; 403 inode->i_mapping->a_ops = &qnx4_aops; 404 qnx4_i(inode)->mmu_private = inode->i_size; 405 } else { 406 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n", 407 ino, sb->s_id); 408 iget_failed(inode); 409 brelse(bh); 410 return ERR_PTR(-EIO); 411 } 412 brelse(bh); 413 unlock_new_inode(inode); 414 return inode; 415 } 416 417 static struct kmem_cache *qnx4_inode_cachep; 418 419 static struct inode *qnx4_alloc_inode(struct super_block *sb) 420 { 421 struct qnx4_inode_info *ei; 422 ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL); 423 if (!ei) 424 return NULL; 425 return &ei->vfs_inode; 426 } 427 428 static void qnx4_i_callback(struct rcu_head *head) 429 { 430 struct inode *inode = container_of(head, struct inode, i_rcu); 431 INIT_LIST_HEAD(&inode->i_dentry); 432 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode)); 433 } 434 435 static void qnx4_destroy_inode(struct inode *inode) 436 { 437 call_rcu(&inode->i_rcu, qnx4_i_callback); 438 } 439 440 static void init_once(void *foo) 441 { 442 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo; 443 444 inode_init_once(&ei->vfs_inode); 445 } 446 447 static int init_inodecache(void) 448 { 449 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache", 450 sizeof(struct qnx4_inode_info), 451 0, (SLAB_RECLAIM_ACCOUNT| 452 SLAB_MEM_SPREAD), 453 init_once); 454 if (qnx4_inode_cachep == NULL) 455 return -ENOMEM; 456 return 0; 457 } 458 459 static void destroy_inodecache(void) 460 { 461 kmem_cache_destroy(qnx4_inode_cachep); 462 } 463 464 static struct dentry *qnx4_mount(struct file_system_type *fs_type, 465 int flags, const char *dev_name, void *data) 466 { 467 return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super); 468 } 469 470 static struct file_system_type qnx4_fs_type = { 471 .owner = THIS_MODULE, 472 .name = "qnx4", 473 .mount = qnx4_mount, 474 .kill_sb = kill_block_super, 475 .fs_flags = FS_REQUIRES_DEV, 476 }; 477 478 static int __init init_qnx4_fs(void) 479 { 480 int err; 481 482 err = init_inodecache(); 483 if (err) 484 return err; 485 486 err = register_filesystem(&qnx4_fs_type); 487 if (err) { 488 destroy_inodecache(); 489 return err; 490 } 491 492 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n"); 493 return 0; 494 } 495 496 static void __exit exit_qnx4_fs(void) 497 { 498 unregister_filesystem(&qnx4_fs_type); 499 destroy_inodecache(); 500 } 501 502 module_init(init_qnx4_fs) 503 module_exit(exit_qnx4_fs) 504 MODULE_LICENSE("GPL"); 505 506