1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * QNX4 file system, Linux implementation. 4 * 5 * Version : 0.2.1 6 * 7 * Using parts of the xiafs filesystem. 8 * 9 * History : 10 * 11 * 01-06-1998 by Richard Frowijn : first release. 12 * 20-06-1998 by Frank Denis : Linux 2.1.99+ support, boot signature, misc. 13 * 30-06-1998 by Frank Denis : first step to write inodes. 14 */ 15 16 #include <linux/module.h> 17 #include <linux/init.h> 18 #include <linux/slab.h> 19 #include <linux/highuid.h> 20 #include <linux/pagemap.h> 21 #include <linux/buffer_head.h> 22 #include <linux/writeback.h> 23 #include <linux/statfs.h> 24 #include <linux/fs_context.h> 25 #include "qnx4.h" 26 27 #define QNX4_VERSION 4 28 #define QNX4_BMNAME ".bitmap" 29 30 static const struct super_operations qnx4_sops; 31 32 static struct inode *qnx4_alloc_inode(struct super_block *sb); 33 static void qnx4_free_inode(struct inode *inode); 34 static int qnx4_statfs(struct dentry *, struct kstatfs *); 35 static int qnx4_get_tree(struct fs_context *fc); 36 37 static const struct super_operations qnx4_sops = 38 { 39 .alloc_inode = qnx4_alloc_inode, 40 .free_inode = qnx4_free_inode, 41 .statfs = qnx4_statfs, 42 }; 43 44 static int qnx4_reconfigure(struct fs_context *fc) 45 { 46 struct super_block *sb = fc->root->d_sb; 47 struct qnx4_sb_info *qs; 48 49 sync_filesystem(sb); 50 qs = qnx4_sb(sb); 51 qs->Version = QNX4_VERSION; 52 fc->sb_flags |= SB_RDONLY; 53 return 0; 54 } 55 56 static const struct fs_context_operations qnx4_context_opts = { 57 .get_tree = qnx4_get_tree, 58 .reconfigure = qnx4_reconfigure, 59 }; 60 61 static int qnx4_get_block( struct inode *inode, sector_t iblock, struct buffer_head *bh, int create ) 62 { 63 unsigned long phys; 64 65 QNX4DEBUG((KERN_INFO "qnx4: qnx4_get_block inode=[%ld] iblock=[%ld]\n",inode->i_ino,iblock)); 66 67 phys = qnx4_block_map( inode, iblock ); 68 if ( phys ) { 69 // logical block is before EOF 70 map_bh(bh, inode->i_sb, phys); 71 } 72 return 0; 73 } 74 75 static inline u32 try_extent(qnx4_xtnt_t *extent, u32 *offset) 76 { 77 u32 size = le32_to_cpu(extent->xtnt_size); 78 if (*offset < size) 79 return le32_to_cpu(extent->xtnt_blk) + *offset - 1; 80 *offset -= size; 81 return 0; 82 } 83 84 unsigned long qnx4_block_map( struct inode *inode, long iblock ) 85 { 86 int ix; 87 long i_xblk; 88 struct buffer_head *bh = NULL; 89 struct qnx4_xblk *xblk = NULL; 90 struct qnx4_inode_entry *qnx4_inode = qnx4_raw_inode(inode); 91 u16 nxtnt = le16_to_cpu(qnx4_inode->di_num_xtnts); 92 u32 offset = iblock; 93 u32 block = try_extent(&qnx4_inode->di_first_xtnt, &offset); 94 95 if (block) { 96 // iblock is in the first extent. This is easy. 97 } else { 98 // iblock is beyond first extent. We have to follow the extent chain. 99 i_xblk = le32_to_cpu(qnx4_inode->di_xblk); 100 ix = 0; 101 while ( --nxtnt > 0 ) { 102 if ( ix == 0 ) { 103 // read next xtnt block. 104 bh = sb_bread(inode->i_sb, i_xblk - 1); 105 if ( !bh ) { 106 QNX4DEBUG((KERN_ERR "qnx4: I/O error reading xtnt block [%ld])\n", i_xblk - 1)); 107 return -EIO; 108 } 109 xblk = (struct qnx4_xblk*)bh->b_data; 110 if ( memcmp( xblk->xblk_signature, "IamXblk", 7 ) ) { 111 QNX4DEBUG((KERN_ERR "qnx4: block at %ld is not a valid xtnt\n", qnx4_inode->i_xblk)); 112 return -EIO; 113 } 114 } 115 block = try_extent(&xblk->xblk_xtnts[ix], &offset); 116 if (block) { 117 // got it! 118 break; 119 } 120 if ( ++ix >= xblk->xblk_num_xtnts ) { 121 i_xblk = le32_to_cpu(xblk->xblk_next_xblk); 122 ix = 0; 123 brelse( bh ); 124 bh = NULL; 125 } 126 } 127 if ( bh ) 128 brelse( bh ); 129 } 130 131 QNX4DEBUG((KERN_INFO "qnx4: mapping block %ld of inode %ld = %ld\n",iblock,inode->i_ino,block)); 132 return block; 133 } 134 135 static int qnx4_statfs(struct dentry *dentry, struct kstatfs *buf) 136 { 137 struct super_block *sb = dentry->d_sb; 138 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 139 140 buf->f_type = sb->s_magic; 141 buf->f_bsize = sb->s_blocksize; 142 buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8; 143 buf->f_bfree = qnx4_count_free_blocks(sb); 144 buf->f_bavail = buf->f_bfree; 145 buf->f_namelen = QNX4_NAME_MAX; 146 buf->f_fsid = u64_to_fsid(id); 147 148 return 0; 149 } 150 151 /* 152 * Check the root directory of the filesystem to make sure 153 * it really _is_ a qnx4 filesystem, and to check the size 154 * of the directory entry. 155 */ 156 static const char *qnx4_checkroot(struct super_block *sb, 157 struct qnx4_super_block *s) 158 { 159 struct buffer_head *bh; 160 struct qnx4_inode_entry *rootdir; 161 int rd, rl; 162 int i, j; 163 164 if (s->RootDir.di_fname[0] != '/' || s->RootDir.di_fname[1] != '\0') 165 return "no qnx4 filesystem (no root dir)."; 166 QNX4DEBUG((KERN_NOTICE "QNX4 filesystem found on dev %s.\n", sb->s_id)); 167 rd = le32_to_cpu(s->RootDir.di_first_xtnt.xtnt_blk) - 1; 168 rl = le32_to_cpu(s->RootDir.di_first_xtnt.xtnt_size); 169 for (j = 0; j < rl; j++) { 170 bh = sb_bread(sb, rd + j); /* root dir, first block */ 171 if (bh == NULL) 172 return "unable to read root entry."; 173 rootdir = (struct qnx4_inode_entry *) bh->b_data; 174 for (i = 0; i < QNX4_INODES_PER_BLOCK; i++, rootdir++) { 175 QNX4DEBUG((KERN_INFO "rootdir entry found : [%s]\n", rootdir->di_fname)); 176 if (strcmp(rootdir->di_fname, QNX4_BMNAME) != 0) 177 continue; 178 qnx4_sb(sb)->BitMap = kmemdup(rootdir, 179 sizeof(struct qnx4_inode_entry), 180 GFP_KERNEL); 181 brelse(bh); 182 if (!qnx4_sb(sb)->BitMap) 183 return "not enough memory for bitmap inode"; 184 /* keep bitmap inode known */ 185 return NULL; 186 } 187 brelse(bh); 188 } 189 return "bitmap file not found."; 190 } 191 192 static int qnx4_fill_super(struct super_block *s, struct fs_context *fc) 193 { 194 struct buffer_head *bh; 195 struct inode *root; 196 const char *errmsg; 197 struct qnx4_sb_info *qs; 198 int silent = fc->sb_flags & SB_SILENT; 199 200 qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL); 201 if (!qs) 202 return -ENOMEM; 203 s->s_fs_info = qs; 204 205 sb_set_blocksize(s, QNX4_BLOCK_SIZE); 206 207 s->s_op = &qnx4_sops; 208 s->s_magic = QNX4_SUPER_MAGIC; 209 s->s_flags |= SB_RDONLY; /* Yup, read-only yet */ 210 s->s_time_min = 0; 211 s->s_time_max = U32_MAX; 212 213 /* Check the superblock signature. Since the qnx4 code is 214 dangerous, we should leave as quickly as possible 215 if we don't belong here... */ 216 bh = sb_bread(s, 1); 217 if (!bh) { 218 printk(KERN_ERR "qnx4: unable to read the superblock\n"); 219 return -EINVAL; 220 } 221 222 /* check before allocating dentries, inodes, .. */ 223 errmsg = qnx4_checkroot(s, (struct qnx4_super_block *) bh->b_data); 224 brelse(bh); 225 if (errmsg != NULL) { 226 if (!silent) 227 printk(KERN_ERR "qnx4: %s\n", errmsg); 228 return -EINVAL; 229 } 230 231 /* does root not have inode number QNX4_ROOT_INO ?? */ 232 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK); 233 if (IS_ERR(root)) { 234 printk(KERN_ERR "qnx4: get inode failed\n"); 235 return PTR_ERR(root); 236 } 237 238 s->s_root = d_make_root(root); 239 if (s->s_root == NULL) 240 return -ENOMEM; 241 242 return 0; 243 } 244 245 static int qnx4_get_tree(struct fs_context *fc) 246 { 247 return get_tree_bdev(fc, qnx4_fill_super); 248 } 249 250 static int qnx4_init_fs_context(struct fs_context *fc) 251 { 252 fc->ops = &qnx4_context_opts; 253 254 return 0; 255 } 256 257 static void qnx4_kill_sb(struct super_block *sb) 258 { 259 struct qnx4_sb_info *qs = qnx4_sb(sb); 260 kill_block_super(sb); 261 if (qs) { 262 kfree(qs->BitMap); 263 kfree(qs); 264 } 265 } 266 267 static int qnx4_read_folio(struct file *file, struct folio *folio) 268 { 269 return block_read_full_folio(folio, qnx4_get_block); 270 } 271 272 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block) 273 { 274 return generic_block_bmap(mapping,block,qnx4_get_block); 275 } 276 277 static const struct address_space_operations qnx4_aops = { 278 .read_folio = qnx4_read_folio, 279 .bmap = qnx4_bmap 280 }; 281 282 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino) 283 { 284 struct buffer_head *bh; 285 struct qnx4_inode_entry *raw_inode; 286 int block; 287 struct qnx4_inode_entry *qnx4_inode; 288 struct inode *inode; 289 290 inode = iget_locked(sb, ino); 291 if (!inode) 292 return ERR_PTR(-ENOMEM); 293 if (!(inode->i_state & I_NEW)) 294 return inode; 295 296 qnx4_inode = qnx4_raw_inode(inode); 297 inode->i_mode = 0; 298 299 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino)); 300 if (!ino) { 301 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is " 302 "out of range\n", 303 sb->s_id, ino); 304 iget_failed(inode); 305 return ERR_PTR(-EIO); 306 } 307 block = ino / QNX4_INODES_PER_BLOCK; 308 309 if (!(bh = sb_bread(sb, block))) { 310 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev " 311 "%s\n", sb->s_id); 312 iget_failed(inode); 313 return ERR_PTR(-EIO); 314 } 315 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) + 316 (ino % QNX4_INODES_PER_BLOCK); 317 318 inode->i_mode = le16_to_cpu(raw_inode->di_mode); 319 i_uid_write(inode, (uid_t)le16_to_cpu(raw_inode->di_uid)); 320 i_gid_write(inode, (gid_t)le16_to_cpu(raw_inode->di_gid)); 321 set_nlink(inode, le16_to_cpu(raw_inode->di_nlink)); 322 inode->i_size = le32_to_cpu(raw_inode->di_size); 323 inode_set_mtime(inode, le32_to_cpu(raw_inode->di_mtime), 0); 324 inode_set_atime(inode, le32_to_cpu(raw_inode->di_atime), 0); 325 inode_set_ctime(inode, le32_to_cpu(raw_inode->di_ctime), 0); 326 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size); 327 328 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE); 329 if (S_ISREG(inode->i_mode)) { 330 inode->i_fop = &generic_ro_fops; 331 inode->i_mapping->a_ops = &qnx4_aops; 332 qnx4_i(inode)->mmu_private = inode->i_size; 333 } else if (S_ISDIR(inode->i_mode)) { 334 inode->i_op = &qnx4_dir_inode_operations; 335 inode->i_fop = &qnx4_dir_operations; 336 } else if (S_ISLNK(inode->i_mode)) { 337 inode->i_op = &page_symlink_inode_operations; 338 inode_nohighmem(inode); 339 inode->i_mapping->a_ops = &qnx4_aops; 340 qnx4_i(inode)->mmu_private = inode->i_size; 341 } else { 342 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n", 343 ino, sb->s_id); 344 iget_failed(inode); 345 brelse(bh); 346 return ERR_PTR(-EIO); 347 } 348 brelse(bh); 349 unlock_new_inode(inode); 350 return inode; 351 } 352 353 static struct kmem_cache *qnx4_inode_cachep; 354 355 static struct inode *qnx4_alloc_inode(struct super_block *sb) 356 { 357 struct qnx4_inode_info *ei; 358 ei = alloc_inode_sb(sb, qnx4_inode_cachep, GFP_KERNEL); 359 if (!ei) 360 return NULL; 361 return &ei->vfs_inode; 362 } 363 364 static void qnx4_free_inode(struct inode *inode) 365 { 366 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode)); 367 } 368 369 static void init_once(void *foo) 370 { 371 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo; 372 373 inode_init_once(&ei->vfs_inode); 374 } 375 376 static int init_inodecache(void) 377 { 378 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache", 379 sizeof(struct qnx4_inode_info), 380 0, (SLAB_RECLAIM_ACCOUNT| 381 SLAB_ACCOUNT), 382 init_once); 383 if (qnx4_inode_cachep == NULL) 384 return -ENOMEM; 385 return 0; 386 } 387 388 static void destroy_inodecache(void) 389 { 390 /* 391 * Make sure all delayed rcu free inodes are flushed before we 392 * destroy cache. 393 */ 394 rcu_barrier(); 395 kmem_cache_destroy(qnx4_inode_cachep); 396 } 397 398 static struct file_system_type qnx4_fs_type = { 399 .owner = THIS_MODULE, 400 .name = "qnx4", 401 .kill_sb = qnx4_kill_sb, 402 .fs_flags = FS_REQUIRES_DEV, 403 .init_fs_context = qnx4_init_fs_context, 404 }; 405 MODULE_ALIAS_FS("qnx4"); 406 407 static int __init init_qnx4_fs(void) 408 { 409 int err; 410 411 err = init_inodecache(); 412 if (err) 413 return err; 414 415 err = register_filesystem(&qnx4_fs_type); 416 if (err) { 417 destroy_inodecache(); 418 return err; 419 } 420 421 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n"); 422 return 0; 423 } 424 425 static void __exit exit_qnx4_fs(void) 426 { 427 unregister_filesystem(&qnx4_fs_type); 428 destroy_inodecache(); 429 } 430 431 module_init(init_qnx4_fs) 432 module_exit(exit_qnx4_fs) 433 MODULE_LICENSE("GPL"); 434 435