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 "qnx4.h" 25 26 #define QNX4_VERSION 4 27 #define QNX4_BMNAME ".bitmap" 28 29 static const struct super_operations qnx4_sops; 30 31 static struct inode *qnx4_alloc_inode(struct super_block *sb); 32 static void qnx4_free_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 .free_inode = qnx4_free_inode, 40 .statfs = qnx4_statfs, 41 .remount_fs = qnx4_remount, 42 }; 43 44 static int qnx4_remount(struct super_block *sb, int *flags, char *data) 45 { 46 struct qnx4_sb_info *qs; 47 48 sync_filesystem(sb); 49 qs = qnx4_sb(sb); 50 qs->Version = QNX4_VERSION; 51 *flags |= SB_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 = u64_to_fsid(id); 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 s->s_time_min = 0; 204 s->s_time_max = U32_MAX; 205 206 /* Check the superblock signature. Since the qnx4 code is 207 dangerous, we should leave as quickly as possible 208 if we don't belong here... */ 209 bh = sb_bread(s, 1); 210 if (!bh) { 211 printk(KERN_ERR "qnx4: unable to read the superblock\n"); 212 return -EINVAL; 213 } 214 215 /* check before allocating dentries, inodes, .. */ 216 errmsg = qnx4_checkroot(s, (struct qnx4_super_block *) bh->b_data); 217 brelse(bh); 218 if (errmsg != NULL) { 219 if (!silent) 220 printk(KERN_ERR "qnx4: %s\n", errmsg); 221 return -EINVAL; 222 } 223 224 /* does root not have inode number QNX4_ROOT_INO ?? */ 225 root = qnx4_iget(s, QNX4_ROOT_INO * QNX4_INODES_PER_BLOCK); 226 if (IS_ERR(root)) { 227 printk(KERN_ERR "qnx4: get inode failed\n"); 228 return PTR_ERR(root); 229 } 230 231 s->s_root = d_make_root(root); 232 if (s->s_root == NULL) 233 return -ENOMEM; 234 235 return 0; 236 } 237 238 static void qnx4_kill_sb(struct super_block *sb) 239 { 240 struct qnx4_sb_info *qs = qnx4_sb(sb); 241 kill_block_super(sb); 242 if (qs) { 243 kfree(qs->BitMap); 244 kfree(qs); 245 } 246 } 247 248 static int qnx4_read_folio(struct file *file, struct folio *folio) 249 { 250 return block_read_full_folio(folio, qnx4_get_block); 251 } 252 253 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block) 254 { 255 return generic_block_bmap(mapping,block,qnx4_get_block); 256 } 257 258 static const struct address_space_operations qnx4_aops = { 259 .read_folio = qnx4_read_folio, 260 .bmap = qnx4_bmap 261 }; 262 263 struct inode *qnx4_iget(struct super_block *sb, unsigned long ino) 264 { 265 struct buffer_head *bh; 266 struct qnx4_inode_entry *raw_inode; 267 int block; 268 struct qnx4_inode_entry *qnx4_inode; 269 struct inode *inode; 270 271 inode = iget_locked(sb, ino); 272 if (!inode) 273 return ERR_PTR(-ENOMEM); 274 if (!(inode->i_state & I_NEW)) 275 return inode; 276 277 qnx4_inode = qnx4_raw_inode(inode); 278 inode->i_mode = 0; 279 280 QNX4DEBUG((KERN_INFO "reading inode : [%d]\n", ino)); 281 if (!ino) { 282 printk(KERN_ERR "qnx4: bad inode number on dev %s: %lu is " 283 "out of range\n", 284 sb->s_id, ino); 285 iget_failed(inode); 286 return ERR_PTR(-EIO); 287 } 288 block = ino / QNX4_INODES_PER_BLOCK; 289 290 if (!(bh = sb_bread(sb, block))) { 291 printk(KERN_ERR "qnx4: major problem: unable to read inode from dev " 292 "%s\n", sb->s_id); 293 iget_failed(inode); 294 return ERR_PTR(-EIO); 295 } 296 raw_inode = ((struct qnx4_inode_entry *) bh->b_data) + 297 (ino % QNX4_INODES_PER_BLOCK); 298 299 inode->i_mode = le16_to_cpu(raw_inode->di_mode); 300 i_uid_write(inode, (uid_t)le16_to_cpu(raw_inode->di_uid)); 301 i_gid_write(inode, (gid_t)le16_to_cpu(raw_inode->di_gid)); 302 set_nlink(inode, le16_to_cpu(raw_inode->di_nlink)); 303 inode->i_size = le32_to_cpu(raw_inode->di_size); 304 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->di_mtime); 305 inode->i_mtime.tv_nsec = 0; 306 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->di_atime); 307 inode->i_atime.tv_nsec = 0; 308 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->di_ctime); 309 inode->i_ctime.tv_nsec = 0; 310 inode->i_blocks = le32_to_cpu(raw_inode->di_first_xtnt.xtnt_size); 311 312 memcpy(qnx4_inode, raw_inode, QNX4_DIR_ENTRY_SIZE); 313 if (S_ISREG(inode->i_mode)) { 314 inode->i_fop = &generic_ro_fops; 315 inode->i_mapping->a_ops = &qnx4_aops; 316 qnx4_i(inode)->mmu_private = inode->i_size; 317 } else if (S_ISDIR(inode->i_mode)) { 318 inode->i_op = &qnx4_dir_inode_operations; 319 inode->i_fop = &qnx4_dir_operations; 320 } else if (S_ISLNK(inode->i_mode)) { 321 inode->i_op = &page_symlink_inode_operations; 322 inode_nohighmem(inode); 323 inode->i_mapping->a_ops = &qnx4_aops; 324 qnx4_i(inode)->mmu_private = inode->i_size; 325 } else { 326 printk(KERN_ERR "qnx4: bad inode %lu on dev %s\n", 327 ino, sb->s_id); 328 iget_failed(inode); 329 brelse(bh); 330 return ERR_PTR(-EIO); 331 } 332 brelse(bh); 333 unlock_new_inode(inode); 334 return inode; 335 } 336 337 static struct kmem_cache *qnx4_inode_cachep; 338 339 static struct inode *qnx4_alloc_inode(struct super_block *sb) 340 { 341 struct qnx4_inode_info *ei; 342 ei = alloc_inode_sb(sb, qnx4_inode_cachep, GFP_KERNEL); 343 if (!ei) 344 return NULL; 345 return &ei->vfs_inode; 346 } 347 348 static void qnx4_free_inode(struct inode *inode) 349 { 350 kmem_cache_free(qnx4_inode_cachep, qnx4_i(inode)); 351 } 352 353 static void init_once(void *foo) 354 { 355 struct qnx4_inode_info *ei = (struct qnx4_inode_info *) foo; 356 357 inode_init_once(&ei->vfs_inode); 358 } 359 360 static int init_inodecache(void) 361 { 362 qnx4_inode_cachep = kmem_cache_create("qnx4_inode_cache", 363 sizeof(struct qnx4_inode_info), 364 0, (SLAB_RECLAIM_ACCOUNT| 365 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 366 init_once); 367 if (qnx4_inode_cachep == NULL) 368 return -ENOMEM; 369 return 0; 370 } 371 372 static void destroy_inodecache(void) 373 { 374 /* 375 * Make sure all delayed rcu free inodes are flushed before we 376 * destroy cache. 377 */ 378 rcu_barrier(); 379 kmem_cache_destroy(qnx4_inode_cachep); 380 } 381 382 static struct dentry *qnx4_mount(struct file_system_type *fs_type, 383 int flags, const char *dev_name, void *data) 384 { 385 return mount_bdev(fs_type, flags, dev_name, data, qnx4_fill_super); 386 } 387 388 static struct file_system_type qnx4_fs_type = { 389 .owner = THIS_MODULE, 390 .name = "qnx4", 391 .mount = qnx4_mount, 392 .kill_sb = qnx4_kill_sb, 393 .fs_flags = FS_REQUIRES_DEV, 394 }; 395 MODULE_ALIAS_FS("qnx4"); 396 397 static int __init init_qnx4_fs(void) 398 { 399 int err; 400 401 err = init_inodecache(); 402 if (err) 403 return err; 404 405 err = register_filesystem(&qnx4_fs_type); 406 if (err) { 407 destroy_inodecache(); 408 return err; 409 } 410 411 printk(KERN_INFO "QNX4 filesystem 0.2.3 registered.\n"); 412 return 0; 413 } 414 415 static void __exit exit_qnx4_fs(void) 416 { 417 unregister_filesystem(&qnx4_fs_type); 418 destroy_inodecache(); 419 } 420 421 module_init(init_qnx4_fs) 422 module_exit(exit_qnx4_fs) 423 MODULE_LICENSE("GPL"); 424 425