| 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 | |