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 int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create ) 56 { 57 unsigned long phys; 58 59 QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock)); 60 61 phys = qnx4_block_map( inode, iblock ); 62 if ( phys ) { 63 // logical block is before EOF 64 map_bh(bh, inode->i_sb, phys); 65 } 66 return 0; 67 } 68 69 static inline u32 try_extent(qnx4_xtnt_t *extent, u32 *offset) 70 { 71 u32 size = le32_to_cpu(extent->xtnt_size); 72 if (*offset < size) 73 return le32_to_cpu(extent->xtnt_blk) + *offset - 1; 74 *offset -= size; 75 return 0; 76 } 77 78 unsigned long qnx4_block_map( struct inode *inode, long iblock ) 79 { 80 int ix; 81 long i_xblk; 82 struct buffer_head *bh = NULL; 83 struct qnx4_xblk *xblk = NULL; 84 struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode); 85 u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts); 86 u32 offset = iblock; 87 u32 block = try_extent(&qnx4_inode->di_first_xtnt, &offset); 88 89 if (block) { 90 // iblock is in the first extent. This is easy. 91 } else { 92 // iblock is beyond first extent. We have to follow the extent chain. 93 i_xblk = le32_to_cpu(qnx4_inode->di_xblk); 94 ix = 0; 95 while ( --nxtnt > 0 ) { 96 if ( ix == 0 ) { 97 // read next xtnt block. 98 bh = sb_bread(inode->i_sb, i_xblk - 1); 99 if ( !bh ) { 100 QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1)); 101 return -EIO; 102 } 103 xblk = (struct qnx4_xblk*)bh->b_data; 104 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) { 105 QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk)); 106 return -EIO; 107 } 108 } 109 block = try_extent(&xblk->xblk_xtnts[ix], &offset); 110 if (block) { 111 // got it! 112 break; 113 } 114 if ( ++ix >= xblk->xblk_num_xtnts ) { 115 i_xblk = le32_to_cpu(xblk->xblk_next_xblk); 116 ix = 0; 117 brelse( bh ); 118 bh = NULL; 119 } 120 } 121 if ( bh ) 122 brelse( bh ); 123 } 124 125 QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block)); 126 return block; 127 } 128 129 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf) 130 { 131 struct super_block *sb = dentry->d_sb; 132 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 133 134 buf->f_type = sb->s_magic; 135 buf->f_bsize = sb->s_blocksize; 136 buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8; 137 buf->f_bfree = qnx4_count_free_blocks(sb); 138 buf->f_bavail = buf->f_bfree; 139 buf->f_namelen = QNX4_NAME_MAX; 140 buf->f_fsid.val[0] = (u32)id; 141 buf->f_fsid.val[1] = (u32)(id >> 32); 142 143 return 0; 144 } 145 146 /* 147 * Check the root directory of the filesystem to make sure 148 * it really _is_ a qnx4 filesystem, and to check the size 149 * of the directory entry. 150 */ 151 static const char *qnx4_checkroot(struct super_block *sb) 152 { 153 struct buffer_head *bh; 154 struct qnx4_inode_entry *rootdir; 155 int rd, rl; 156 int i, j; 157 158 if (*(qnx4_sb(sb)->sb->RootDir.di_fname) != '/') 159 return "no qnx4 filesystem (no root dir)."; 160 QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id)); 161 rd = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_blk) - 1; 162 rl = le32_to_cpu(qnx4_sb(sb)->sb->RootDir.di_first_xtnt.xtnt_size); 163 for (j = 0; j < rl; j++) { 164 bh = sb_bread(sb, rd + j); /* root dir, first block */ 165 if (bh == NULL) 166 return "unable to read root entry."; 167 rootdir = (struct qnx4_inode_entry *) bh->b_data; 168 for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) { 169 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname)); 170 if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0) 171 continue; 172 qnx4_sb(sb)->BitMap = kmemdup(rootdir, 173 sizeof(struct qnx4_inode_entry), 174 GFP_KERNEL); 175 brelse(bh); 176 if (!qnx4_sb(sb)->BitMap) 177 return "not enough memory for bitmap inode"; 178 /* keep bitmap inode known */ 179 return NULL; 180 } 181 brelse(bh); 182 } 183 return "bitmap file not found."; 184 } 185 186 static int qnx4_fill_super(struct super_block *s, void *data, int silent) 187 { 188 struct buffer_head *bh; 189 struct inode *root; 190 const char *errmsg; 191 struct qnx4_sb_info *qs; 192 int ret = -EINVAL; 193 194 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL); 195 if (!qs) 196 return -ENOMEM; 197 s->s_fs_info = qs; 198 199 sb_set_blocksize(s, QNX4_BLOCK_SIZE); 200 201 /* Check the superblock signature. Since the qnx4 code is 202 dangerous, we should leave as quickly as possible 203 if we don't belong here... */ 204 bh = sb_bread(s, 1); 205 if (!bh) { 206 printk(KERN_ERR "qnx4: unable to read the superblock\n"); 207 goto outnobh; 208 } 209 if ( le32_to_cpup((__le32*) bh->b_data) != QNX4_SUPER_MAGIC ) { 210 if (!silent) 211 printk(KERN_ERR "qnx4: wrong fsid in superblock.\n"); 212 goto out; 213 } 214 s->s_op = &qnx4_sops; 215 s->s_magic = QNX4_SUPER_MAGIC; 216 s->s_flags |= MS_RDONLY; /* Yup, read-only yet */ 217 qnx4_sb(s)->sb_buf = bh; 218 qnx4_sb(s)->sb = (struct qnx4_super_block *) bh->b_data; 219 220 221 /* check before allocating dentries, inodes, .. */ 222 errmsg = qnx4_checkroot(s); 223 if (errmsg != NULL) { 224 if (!silent) 225 printk(KERN_ERR "qnx4: %s\n", errmsg); 226 goto out; 227 } 228 229 /* does root not have inode number QNX4_ROOT_INO ?? */ 230 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK); 231 if (IS_ERR(root)) { 232 printk(KERN_ERR "qnx4: get inode failed\n"); 233 ret = PTR_ERR(root); 234 goto outb; 235 } 236 237 ret = -ENOMEM; 238 s->s_root = d_make_root(root); 239 if (s->s_root == NULL) 240 goto outb; 241 242 brelse(bh); 243 return 0; 244 245 outb: 246 kfree(qs->BitMap); 247 out: 248 brelse(bh); 249 outnobh: 250 kfree(qs); 251 s->s_fs_info = NULL; 252 return ret; 253 } 254 255 static void qnx4_put_super(struct super_block *sb) 256 { 257 struct qnx4_sb_info *qs = qnx4_sb(sb); 258 kfree( qs->BitMap ); 259 kfree( qs ); 260 sb->s_fs_info = NULL; 261 return; 262 } 263 264 static int qnx4_readpage(struct file *file, struct page *page) 265 { 266 return block_read_full_page(page,qnx4_get_block); 267 } 268 269 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block) 270 { 271 return generic_block_bmap(mapping,block,qnx4_get_block); 272 } 273 static const struct address_space_operations qnx4_aops = { 274 .readpage = qnx4_readpage, 275 .bmap = qnx4_bmap 276 }; 277 278 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino) 279 { 280 struct buffer_head *bh; 281 struct qnx4_inode_entry *raw_inode; 282 int block; 283 struct qnx4_inode_entry *qnx4_inode; 284 struct inode *inode; 285 286 inode = iget_locked(sb, ino); 287 if (!inode) 288 return ERR_PTR(-ENOMEM); 289 if (!(inode->i_state & I_NEW)) 290 return inode; 291 292 qnx4_inode = qnx4_raw_inode(inode); 293 inode->i_mode = 0; 294 295 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino)); 296 if (!ino) { 297 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is " 298 "out of range\n", 299 sb->s_id, ino); 300 iget_failed(inode); 301 return ERR_PTR(-EIO); 302 } 303 block = ino / QNX4_INODES_PER_BLOCK; 304 305 if (!(bh = sb_bread(sb, block))) { 306 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev " 307 "%s\n", sb->s_id); 308 iget_failed(inode); 309 return ERR_PTR(-EIO); 310 } 311 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) + 312 (ino % QNX4_INODES_PER_BLOCK); 313 314 inode->i_mode = le16_to_cpu(raw_inode->di_mode); 315 i_uid_write(inode, (uid_t)le16_to_cpu(raw_inode->di_uid)); 316 i_gid_write(inode, (gid_t)le16_to_cpu(raw_inode->di_gid)); 317 set_nlink(inode, le16_to_cpu(raw_inode->di_nlink)); 318 inode->i_size = le32_to_cpu(raw_inode->di_size); 319 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime); 320 inode->i_mtime.tv_nsec = 0; 321 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime); 322 inode->i_atime.tv_nsec = 0; 323 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime); 324 inode->i_ctime.tv_nsec = 0; 325 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size); 326 327 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE); 328 if (S_ISREG(inode->i_mode)) { 329 inode->i_fop = &generic_ro_fops; 330 inode->i_mapping->a_ops = &qnx4_aops; 331 qnx4_i(inode)->mmu_private = inode->i_size; 332 } else if (S_ISDIR(inode->i_mode)) { 333 inode->i_op = &qnx4_dir_inode_operations; 334 inode->i_fop = &qnx4_dir_operations; 335 } else if (S_ISLNK(inode->i_mode)) { 336 inode->i_op = &page_symlink_inode_operations; 337 inode->i_mapping->a_ops = &qnx4_aops; 338 qnx4_i(inode)->mmu_private = inode->i_size; 339 } else { 340 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n", 341 ino, sb->s_id); 342 iget_failed(inode); 343 brelse(bh); 344 return ERR_PTR(-EIO); 345 } 346 brelse(bh); 347 unlock_new_inode(inode); 348 return inode; 349 } 350 351 static struct kmem_cache *qnx4_inode_cachep; 352 353 static struct inode *qnx4_alloc_inode(struct super_block *sb) 354 { 355 struct qnx4_inode_info *ei; 356 ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL); 357 if (!ei) 358 return NULL; 359 return &ei->vfs_inode; 360 } 361 362 static void qnx4_i_callback(struct rcu_head *head) 363 { 364 struct inode *inode = container_of(head, struct inode, i_rcu); 365 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode)); 366 } 367 368 static void qnx4_destroy_inode(struct inode *inode) 369 { 370 call_rcu(&inode->i_rcu, qnx4_i_callback); 371 } 372 373 static void init_once(void *foo) 374 { 375 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo; 376 377 inode_init_once(&ei->vfs_inode); 378 } 379 380 static int init_inodecache(void) 381 { 382 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache", 383 sizeof(struct qnx4_inode_info), 384 0, (SLAB_RECLAIM_ACCOUNT| 385 SLAB_MEM_SPREAD), 386 init_once); 387 if (qnx4_inode_cachep == NULL) 388 return -ENOMEM; 389 return 0; 390 } 391 392 static void destroy_inodecache(void) 393 { 394 /* 395 * Make sure all delayed rcu free inodes are flushed before we 396 * destroy cache. 397 */ 398 rcu_barrier(); 399 kmem_cache_destroy(qnx4_inode_cachep); 400 } 401 402 static struct dentry *qnx4_mount(struct file_system_type *fs_type, 403 int flags, const char *dev_name, void *data) 404 { 405 return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super); 406 } 407 408 static struct file_system_type qnx4_fs_type = { 409 .owner = THIS_MODULE, 410 .name = "qnx4", 411 .mount = qnx4_mount, 412 .kill_sb = kill_block_super, 413 .fs_flags = FS_REQUIRES_DEV, 414 }; 415 MODULE_ALIAS_FS("qnx4"); 416 417 static int __init init_qnx4_fs(void) 418 { 419 int err; 420 421 err = init_inodecache(); 422 if (err) 423 return err; 424 425 err = register_filesystem(&qnx4_fs_type); 426 if (err) { 427 destroy_inodecache(); 428 return err; 429 } 430 431 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n"); 432 return 0; 433 } 434 435 static void __exit exit_qnx4_fs(void) 436 { 437 unregister_filesystem(&qnx4_fs_type); 438 destroy_inodecache(); 439 } 440 441 module_init(init_qnx4_fs) 442 module_exit(exit_qnx4_fs) 443 MODULE_LICENSE("GPL"); 444 445