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; 182 183 if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') 184 return "no qnx4 filesystem (no root dir)."; 185 QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id)); 186 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1; 187 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size); 188 for (j = 0; j < rl; j++) { 189 bh = sb_bread(sb, rd + j); /* root dir, first block */ 190 if (bh == NULL) 191 return "unable to read root entry."; 192 rootdir = (struct qnx4_inode_entry *) bh->b_data; 193 for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) { 194 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname)); 195 if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0) 196 continue; 197 qnx4_sb(sb)->BitMap = kmemdup(rootdir, 198 sizeof(struct qnx4_inode_entry), 199 GFP_KERNEL); 200 brelse(bh); 201 if (!qnx4_sb(sb)->BitMap) 202 return "not enough memory for bitmap inode"; 203 /* keep bitmap inode known */ 204 return NULL; 205 } 206 brelse(bh); 207 } 208 return "bitmap file not found."; 209 } 210 211 static int qnx4_fill_super(struct super_block *s, void *data, int silent) 212 { 213 struct buffer_head *bh; 214 struct inode *root; 215 const char *errmsg; 216 struct qnx4_sb_info *qs; 217 int ret = -EINVAL; 218 219 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL); 220 if (!qs) 221 return -ENOMEM; 222 s->s_fs_info = qs; 223 224 sb_set_blocksize(s, QNX4_BLOCK_SIZE); 225 226 /* Check the superblock signature. Since the qnx4 code is 227 dangerous, we should leave as quickly as possible 228 if we don't belong here... */ 229 bh = sb_bread(s, 1); 230 if (!bh) { 231 printk(KERN_ERR "qnx4: unable to read the superblock\n"); 232 goto outnobh; 233 } 234 if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) { 235 if (!silent) 236 printk(KERN_ERR "qnx4: wrong fsid in superblock.\n"); 237 goto out; 238 } 239 s->s_op = &qnx4_sops; 240 s->s_magic = QNX4_SUPER_MAGIC; 241 s->s_flags |= MS_RDONLY; /* Yup, read-only yet */ 242 qnx4_sb(s)->sb_buf = bh; 243 qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data; 244 245 246 /* check before allocating dentries, inodes, .. */ 247 errmsg = qnx4_checkroot(s); 248 if (errmsg != NULL) { 249 if (!silent) 250 printk(KERN_ERR "qnx4: %s\n", errmsg); 251 goto out; 252 } 253 254 /* does root not have inode number QNX4_ROOT_INO ?? */ 255 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK); 256 if (IS_ERR(root)) { 257 printk(KERN_ERR "qnx4: get inode failed\n"); 258 ret = PTR_ERR(root); 259 goto outb; 260 } 261 262 ret = -ENOMEM; 263 s->s_root = d_alloc_root(root); 264 if (s->s_root == NULL) 265 goto outi; 266 267 brelse(bh); 268 return 0; 269 270 outi: 271 iput(root); 272 outb: 273 kfree(qs->BitMap); 274 out: 275 brelse(bh); 276 outnobh: 277 kfree(qs); 278 s->s_fs_info = NULL; 279 return ret; 280 } 281 282 static void qnx4_put_super(struct super_block *sb) 283 { 284 struct qnx4_sb_info *qs = qnx4_sb(sb); 285 kfree( qs->BitMap ); 286 kfree( qs ); 287 sb->s_fs_info = NULL; 288 return; 289 } 290 291 static int qnx4_writepage(struct page *page, struct writeback_control *wbc) 292 { 293 return block_write_full_page(page,qnx4_get_block, wbc); 294 } 295 296 static int qnx4_readpage(struct file *file, struct page *page) 297 { 298 return block_read_full_page(page,qnx4_get_block); 299 } 300 301 static int qnx4_write_begin(struct file *file, struct address_space *mapping, 302 loff_t pos, unsigned len, unsigned flags, 303 struct page **pagep, void **fsdata) 304 { 305 struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host); 306 int ret; 307 308 *pagep = NULL; 309 ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata, 310 qnx4_get_block, 311 &qnx4_inode->mmu_private); 312 if (unlikely(ret)) { 313 loff_t isize = mapping->host->i_size; 314 if (pos + len > isize) 315 vmtruncate(mapping->host, isize); 316 } 317 318 return ret; 319 } 320 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block) 321 { 322 return generic_block_bmap(mapping,block,qnx4_get_block); 323 } 324 static const struct address_space_operations qnx4_aops = { 325 .readpage = qnx4_readpage, 326 .writepage = qnx4_writepage, 327 .write_begin = qnx4_write_begin, 328 .write_end = generic_write_end, 329 .bmap = qnx4_bmap 330 }; 331 332 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino) 333 { 334 struct buffer_head *bh; 335 struct qnx4_inode_entry *raw_inode; 336 int block; 337 struct qnx4_inode_entry *qnx4_inode; 338 struct inode *inode; 339 340 inode = iget_locked(sb, ino); 341 if (!inode) 342 return ERR_PTR(-ENOMEM); 343 if (!(inode->i_state & I_NEW)) 344 return inode; 345 346 qnx4_inode = qnx4_raw_inode(inode); 347 inode->i_mode = 0; 348 349 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino)); 350 if (!ino) { 351 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is " 352 "out of range\n", 353 sb->s_id, ino); 354 iget_failed(inode); 355 return ERR_PTR(-EIO); 356 } 357 block = ino / QNX4_INODES_PER_BLOCK; 358 359 if (!(bh = sb_bread(sb, block))) { 360 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev " 361 "%s\n", sb->s_id); 362 iget_failed(inode); 363 return ERR_PTR(-EIO); 364 } 365 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) + 366 (ino % QNX4_INODES_PER_BLOCK); 367 368 inode->i_mode = le16_to_cpu(raw_inode->di_mode); 369 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->di_uid); 370 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->di_gid); 371 set_nlink(inode, le16_to_cpu(raw_inode->di_nlink)); 372 inode->i_size = le32_to_cpu(raw_inode->di_size); 373 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime); 374 inode->i_mtime.tv_nsec = 0; 375 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime); 376 inode->i_atime.tv_nsec = 0; 377 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime); 378 inode->i_ctime.tv_nsec = 0; 379 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size); 380 381 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE); 382 if (S_ISREG(inode->i_mode)) { 383 inode->i_fop = &generic_ro_fops; 384 inode->i_mapping->a_ops = &qnx4_aops; 385 qnx4_i(inode)->mmu_private = inode->i_size; 386 } else if (S_ISDIR(inode->i_mode)) { 387 inode->i_op = &qnx4_dir_inode_operations; 388 inode->i_fop = &qnx4_dir_operations; 389 } else if (S_ISLNK(inode->i_mode)) { 390 inode->i_op = &page_symlink_inode_operations; 391 inode->i_mapping->a_ops = &qnx4_aops; 392 qnx4_i(inode)->mmu_private = inode->i_size; 393 } else { 394 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n", 395 ino, sb->s_id); 396 iget_failed(inode); 397 brelse(bh); 398 return ERR_PTR(-EIO); 399 } 400 brelse(bh); 401 unlock_new_inode(inode); 402 return inode; 403 } 404 405 static struct kmem_cache *qnx4_inode_cachep; 406 407 static struct inode *qnx4_alloc_inode(struct super_block *sb) 408 { 409 struct qnx4_inode_info *ei; 410 ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL); 411 if (!ei) 412 return NULL; 413 return &ei->vfs_inode; 414 } 415 416 static void qnx4_i_callback(struct rcu_head *head) 417 { 418 struct inode *inode = container_of(head, struct inode, i_rcu); 419 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode)); 420 } 421 422 static void qnx4_destroy_inode(struct inode *inode) 423 { 424 call_rcu(&inode->i_rcu, qnx4_i_callback); 425 } 426 427 static void init_once(void *foo) 428 { 429 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo; 430 431 inode_init_once(&ei->vfs_inode); 432 } 433 434 static int init_inodecache(void) 435 { 436 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache", 437 sizeof(struct qnx4_inode_info), 438 0, (SLAB_RECLAIM_ACCOUNT| 439 SLAB_MEM_SPREAD), 440 init_once); 441 if (qnx4_inode_cachep == NULL) 442 return -ENOMEM; 443 return 0; 444 } 445 446 static void destroy_inodecache(void) 447 { 448 kmem_cache_destroy(qnx4_inode_cachep); 449 } 450 451 static struct dentry *qnx4_mount(struct file_system_type *fs_type, 452 int flags, const char *dev_name, void *data) 453 { 454 return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super); 455 } 456 457 static struct file_system_type qnx4_fs_type = { 458 .owner = THIS_MODULE, 459 .name = "qnx4", 460 .mount = qnx4_mount, 461 .kill_sb = kill_block_super, 462 .fs_flags = FS_REQUIRES_DEV, 463 }; 464 465 static int __init init_qnx4_fs(void) 466 { 467 int err; 468 469 err = init_inodecache(); 470 if (err) 471 return err; 472 473 err = register_filesystem(&qnx4_fs_type); 474 if (err) { 475 destroy_inodecache(); 476 return err; 477 } 478 479 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n"); 480 return 0; 481 } 482 483 static void __exit exit_qnx4_fs(void) 484 { 485 unregister_filesystem(&qnx4_fs_type); 486 destroy_inodecache(); 487 } 488 489 module_init(init_qnx4_fs) 490 module_exit(exit_qnx4_fs) 491 MODULE_LICENSE("GPL"); 492 493