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 struct inode *qnx4_alloc_inode(struct super_block *sb); 31 static void qnx4_destroy_inode(struct inode *inode); 32 static int qnx4_remount(struct super_block *sb, int *flags, char *data); 33 static int qnx4_statfs(struct dentry *, struct kstatfs *); 34 35 static const struct super_operations qnx4_sops = 36 { 37 .alloc_inode = qnx4_alloc_inode, 38 .destroy_inode = qnx4_destroy_inode, 39 .statfs = qnx4_statfs, 40 .remount_fs = qnx4_remount, 41 }; 42 43 static int qnx4_remount(struct super_block *sb, int *flags, char *data) 44 { 45 struct qnx4_sb_info *qs; 46 47 sync_filesystem(sb); 48 qs = qnx4_sb(sb); 49 qs->Version = QNX4_VERSION; 50 *flags |= SB_RDONLY; 51 return 0; 52 } 53 54 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create ) 55 { 56 unsigned long phys; 57 58 QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock)); 59 60 phys = qnx4_block_map( inode, iblock ); 61 if ( phys ) { 62 // logical block is before EOF 63 map_bh(bh, inode->i_sb, phys); 64 } 65 return 0; 66 } 67 68 static inline u32 try_extent(qnx4_xtnt_t *extent, u32 *offset) 69 { 70 u32 size = le32_to_cpu(extent->xtnt_size); 71 if (*offset < size) 72 return le32_to_cpu(extent->xtnt_blk) + *offset - 1; 73 *offset -= size; 74 return 0; 75 } 76 77 unsigned long qnx4_block_map( struct inode *inode, long iblock ) 78 { 79 int ix; 80 long i_xblk; 81 struct buffer_head *bh = NULL; 82 struct qnx4_xblk *xblk = NULL; 83 struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode); 84 u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts); 85 u32 offset = iblock; 86 u32 block = try_extent(&qnx4_inode->di_first_xtnt, &offset); 87 88 if (block) { 89 // iblock is in the first extent. This is easy. 90 } else { 91 // iblock is beyond first extent. We have to follow the extent chain. 92 i_xblk = le32_to_cpu(qnx4_inode->di_xblk); 93 ix = 0; 94 while ( --nxtnt > 0 ) { 95 if ( ix == 0 ) { 96 // read next xtnt block. 97 bh = sb_bread(inode->i_sb, i_xblk - 1); 98 if ( !bh ) { 99 QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1)); 100 return -EIO; 101 } 102 xblk = (struct qnx4_xblk*)bh->b_data; 103 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) { 104 QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk)); 105 return -EIO; 106 } 107 } 108 block = try_extent(&xblk->xblk_xtnts[ix], &offset); 109 if (block) { 110 // got it! 111 break; 112 } 113 if ( ++ix >= xblk->xblk_num_xtnts ) { 114 i_xblk = le32_to_cpu(xblk->xblk_next_xblk); 115 ix = 0; 116 brelse( bh ); 117 bh = NULL; 118 } 119 } 120 if ( bh ) 121 brelse( bh ); 122 } 123 124 QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block)); 125 return block; 126 } 127 128 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf) 129 { 130 struct super_block *sb = dentry->d_sb; 131 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 132 133 buf->f_type = sb->s_magic; 134 buf->f_bsize = sb->s_blocksize; 135 buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8; 136 buf->f_bfree = qnx4_count_free_blocks(sb); 137 buf->f_bavail = buf->f_bfree; 138 buf->f_namelen = QNX4_NAME_MAX; 139 buf->f_fsid.val[0] = (u32)id; 140 buf->f_fsid.val[1] = (u32)(id >> 32); 141 142 return 0; 143 } 144 145 /* 146 * Check the root directory of the filesystem to make sure 147 * it really _is_ a qnx4 filesystem, and to check the size 148 * of the directory entry. 149 */ 150 static const char *qnx4_checkroot(struct super_block *sb, 151 struct qnx4_super_block *s) 152 { 153 struct buffer_head *bh; 154 struct qnx4_inode_entry *rootdir; 155 int rd, rl; 156 int i, j; 157 158 if (s->RootDir.di_fname[0] != '/' || s->RootDir.di_fname[1] != '\0') 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(s->RootDir.di_first_xtnt.xtnt_blk) - 1; 162 rl = le32_to_cpu(s->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; 192 193 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL); 194 if (!qs) 195 return -ENOMEM; 196 s->s_fs_info = qs; 197 198 sb_set_blocksize(s, QNX4_BLOCK_SIZE); 199 200 s->s_op = &qnx4_sops; 201 s->s_magic = QNX4_SUPER_MAGIC; 202 s->s_flags |= SB_RDONLY; /* Yup, read-only yet */ 203 204 /* Check the superblock signature. Since the qnx4 code is 205 dangerous, we should leave as quickly as possible 206 if we don't belong here... */ 207 bh = sb_bread(s, 1); 208 if (!bh) { 209 printk(KERN_ERR "qnx4: unable to read the superblock\n"); 210 return -EINVAL; 211 } 212 213 /* check before allocating dentries, inodes, .. */ 214 errmsg = qnx4_checkroot(s, (struct qnx4_super_block *) bh->b_data); 215 brelse(bh); 216 if (errmsg != NULL) { 217 if (!silent) 218 printk(KERN_ERR "qnx4: %s\n", errmsg); 219 return -EINVAL; 220 } 221 222 /* does root not have inode number QNX4_ROOT_INO ?? */ 223 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK); 224 if (IS_ERR(root)) { 225 printk(KERN_ERR "qnx4: get inode failed\n"); 226 return PTR_ERR(root); 227 } 228 229 s->s_root = d_make_root(root); 230 if (s->s_root == NULL) 231 return -ENOMEM; 232 233 return 0; 234 } 235 236 static void qnx4_kill_sb(struct super_block *sb) 237 { 238 struct qnx4_sb_info *qs = qnx4_sb(sb); 239 kill_block_super(sb); 240 if (qs) { 241 kfree(qs->BitMap); 242 kfree(qs); 243 } 244 } 245 246 static int qnx4_readpage(struct file *file, struct page *page) 247 { 248 return block_read_full_page(page,qnx4_get_block); 249 } 250 251 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block) 252 { 253 return generic_block_bmap(mapping,block,qnx4_get_block); 254 } 255 static const struct address_space_operations qnx4_aops = { 256 .readpage = qnx4_readpage, 257 .bmap = qnx4_bmap 258 }; 259 260 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino) 261 { 262 struct buffer_head *bh; 263 struct qnx4_inode_entry *raw_inode; 264 int block; 265 struct qnx4_inode_entry *qnx4_inode; 266 struct inode *inode; 267 268 inode = iget_locked(sb, ino); 269 if (!inode) 270 return ERR_PTR(-ENOMEM); 271 if (!(inode->i_state & I_NEW)) 272 return inode; 273 274 qnx4_inode = qnx4_raw_inode(inode); 275 inode->i_mode = 0; 276 277 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino)); 278 if (!ino) { 279 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is " 280 "out of range\n", 281 sb->s_id, ino); 282 iget_failed(inode); 283 return ERR_PTR(-EIO); 284 } 285 block = ino / QNX4_INODES_PER_BLOCK; 286 287 if (!(bh = sb_bread(sb, block))) { 288 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev " 289 "%s\n", sb->s_id); 290 iget_failed(inode); 291 return ERR_PTR(-EIO); 292 } 293 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) + 294 (ino % QNX4_INODES_PER_BLOCK); 295 296 inode->i_mode = le16_to_cpu(raw_inode->di_mode); 297 i_uid_write(inode, (uid_t)le16_to_cpu(raw_inode->di_uid)); 298 i_gid_write(inode, (gid_t)le16_to_cpu(raw_inode->di_gid)); 299 set_nlink(inode, le16_to_cpu(raw_inode->di_nlink)); 300 inode->i_size = le32_to_cpu(raw_inode->di_size); 301 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime); 302 inode->i_mtime.tv_nsec = 0; 303 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime); 304 inode->i_atime.tv_nsec = 0; 305 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime); 306 inode->i_ctime.tv_nsec = 0; 307 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size); 308 309 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE); 310 if (S_ISREG(inode->i_mode)) { 311 inode->i_fop = &generic_ro_fops; 312 inode->i_mapping->a_ops = &qnx4_aops; 313 qnx4_i(inode)->mmu_private = inode->i_size; 314 } else if (S_ISDIR(inode->i_mode)) { 315 inode->i_op = &qnx4_dir_inode_operations; 316 inode->i_fop = &qnx4_dir_operations; 317 } else if (S_ISLNK(inode->i_mode)) { 318 inode->i_op = &page_symlink_inode_operations; 319 inode_nohighmem(inode); 320 inode->i_mapping->a_ops = &qnx4_aops; 321 qnx4_i(inode)->mmu_private = inode->i_size; 322 } else { 323 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n", 324 ino, sb->s_id); 325 iget_failed(inode); 326 brelse(bh); 327 return ERR_PTR(-EIO); 328 } 329 brelse(bh); 330 unlock_new_inode(inode); 331 return inode; 332 } 333 334 static struct kmem_cache *qnx4_inode_cachep; 335 336 static struct inode *qnx4_alloc_inode(struct super_block *sb) 337 { 338 struct qnx4_inode_info *ei; 339 ei = kmem_cache_alloc(qnx4_inode_cachep, GFP_KERNEL); 340 if (!ei) 341 return NULL; 342 return &ei->vfs_inode; 343 } 344 345 static void qnx4_i_callback(struct rcu_head *head) 346 { 347 struct inode *inode = container_of(head, struct inode, i_rcu); 348 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode)); 349 } 350 351 static void qnx4_destroy_inode(struct inode *inode) 352 { 353 call_rcu(&inode->i_rcu, qnx4_i_callback); 354 } 355 356 static void init_once(void *foo) 357 { 358 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo; 359 360 inode_init_once(&ei->vfs_inode); 361 } 362 363 static int init_inodecache(void) 364 { 365 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache", 366 sizeof(struct qnx4_inode_info), 367 0, (SLAB_RECLAIM_ACCOUNT| 368 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 369 init_once); 370 if (qnx4_inode_cachep == NULL) 371 return -ENOMEM; 372 return 0; 373 } 374 375 static void destroy_inodecache(void) 376 { 377 /* 378 * Make sure all delayed rcu free inodes are flushed before we 379 * destroy cache. 380 */ 381 rcu_barrier(); 382 kmem_cache_destroy(qnx4_inode_cachep); 383 } 384 385 static struct dentry *qnx4_mount(struct file_system_type *fs_type, 386 int flags, const char *dev_name, void *data) 387 { 388 return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super); 389 } 390 391 static struct file_system_type qnx4_fs_type = { 392 .owner = THIS_MODULE, 393 .name = "qnx4", 394 .mount = qnx4_mount, 395 .kill_sb = qnx4_kill_sb, 396 .fs_flags = FS_REQUIRES_DEV, 397 }; 398 MODULE_ALIAS_FS("qnx4"); 399 400 static int __init init_qnx4_fs(void) 401 { 402 int err; 403 404 err = init_inodecache(); 405 if (err) 406 return err; 407 408 err = register_filesystem(&qnx4_fs_type); 409 if (err) { 410 destroy_inodecache(); 411 return err; 412 } 413 414 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n"); 415 return 0; 416 } 417 418 static void __exit exit_qnx4_fs(void) 419 { 420 unregister_filesystem(&qnx4_fs_type); 421 destroy_inodecache(); 422 } 423 424 module_init(init_qnx4_fs) 425 module_exit(exit_qnx4_fs) 426 MODULE_LICENSE("GPL"); 427 428