1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. 4 */ 5 6 #include <linux/slab.h> 7 #include <linux/compat.h> 8 #include <linux/cred.h> 9 #include <linux/buffer_head.h> 10 #include <linux/blkdev.h> 11 12 #include "exfat_raw.h" 13 #include "exfat_fs.h" 14 15 static int exfat_cont_expand(struct inode *inode, loff_t size) 16 { 17 struct address_space *mapping = inode->i_mapping; 18 loff_t start = i_size_read(inode), count = size - i_size_read(inode); 19 int err, err2; 20 21 err = generic_cont_expand_simple(inode, size); 22 if (err) 23 return err; 24 25 inode->i_ctime = inode->i_mtime = current_time(inode); 26 mark_inode_dirty(inode); 27 28 if (!IS_SYNC(inode)) 29 return 0; 30 31 err = filemap_fdatawrite_range(mapping, start, start + count - 1); 32 err2 = sync_mapping_buffers(mapping); 33 if (!err) 34 err = err2; 35 err2 = write_inode_now(inode, 1); 36 if (!err) 37 err = err2; 38 if (err) 39 return err; 40 41 return filemap_fdatawait_range(mapping, start, start + count - 1); 42 } 43 44 static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode) 45 { 46 mode_t allow_utime = sbi->options.allow_utime; 47 48 if (!uid_eq(current_fsuid(), inode->i_uid)) { 49 if (in_group_p(inode->i_gid)) 50 allow_utime >>= 3; 51 if (allow_utime & MAY_WRITE) 52 return true; 53 } 54 55 /* use a default check */ 56 return false; 57 } 58 59 static int exfat_sanitize_mode(const struct exfat_sb_info *sbi, 60 struct inode *inode, umode_t *mode_ptr) 61 { 62 mode_t i_mode, mask, perm; 63 64 i_mode = inode->i_mode; 65 66 mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ? 67 sbi->options.fs_fmask : sbi->options.fs_dmask; 68 perm = *mode_ptr & ~(S_IFMT | mask); 69 70 /* Of the r and x bits, all (subject to umask) must be present.*/ 71 if ((perm & 0555) != (i_mode & 0555)) 72 return -EPERM; 73 74 if (exfat_mode_can_hold_ro(inode)) { 75 /* 76 * Of the w bits, either all (subject to umask) or none must 77 * be present. 78 */ 79 if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask))) 80 return -EPERM; 81 } else { 82 /* 83 * If exfat_mode_can_hold_ro(inode) is false, can't change 84 * w bits. 85 */ 86 if ((perm & 0222) != (0222 & ~mask)) 87 return -EPERM; 88 } 89 90 *mode_ptr &= S_IFMT | perm; 91 92 return 0; 93 } 94 95 /* resize the file length */ 96 int __exfat_truncate(struct inode *inode, loff_t new_size) 97 { 98 unsigned int num_clusters_new, num_clusters_phys; 99 unsigned int last_clu = EXFAT_FREE_CLUSTER; 100 struct exfat_chain clu; 101 struct super_block *sb = inode->i_sb; 102 struct exfat_sb_info *sbi = EXFAT_SB(sb); 103 struct exfat_inode_info *ei = EXFAT_I(inode); 104 int evict = (ei->dir.dir == DIR_DELETED) ? 1 : 0; 105 106 /* check if the given file ID is opened */ 107 if (ei->type != TYPE_FILE && ei->type != TYPE_DIR) 108 return -EPERM; 109 110 exfat_set_volume_dirty(sb); 111 112 num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi); 113 num_clusters_phys = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi); 114 115 exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags); 116 117 if (new_size > 0) { 118 /* 119 * Truncate FAT chain num_clusters after the first cluster 120 * num_clusters = min(new, phys); 121 */ 122 unsigned int num_clusters = 123 min(num_clusters_new, num_clusters_phys); 124 125 /* 126 * Follow FAT chain 127 * (defensive coding - works fine even with corrupted FAT table 128 */ 129 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 130 clu.dir += num_clusters; 131 clu.size -= num_clusters; 132 } else { 133 while (num_clusters > 0) { 134 last_clu = clu.dir; 135 if (exfat_get_next_cluster(sb, &(clu.dir))) 136 return -EIO; 137 138 num_clusters--; 139 clu.size--; 140 } 141 } 142 } else { 143 ei->flags = ALLOC_NO_FAT_CHAIN; 144 ei->start_clu = EXFAT_EOF_CLUSTER; 145 } 146 147 i_size_write(inode, new_size); 148 149 if (ei->type == TYPE_FILE) 150 ei->attr |= ATTR_ARCHIVE; 151 152 /* update the directory entry */ 153 if (!evict) { 154 struct timespec64 ts; 155 struct exfat_dentry *ep, *ep2; 156 struct exfat_entry_set_cache *es; 157 int err; 158 159 es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry, 160 ES_ALL_ENTRIES); 161 if (!es) 162 return -EIO; 163 ep = exfat_get_dentry_cached(es, 0); 164 ep2 = exfat_get_dentry_cached(es, 1); 165 166 ts = current_time(inode); 167 exfat_set_entry_time(sbi, &ts, 168 &ep->dentry.file.modify_tz, 169 &ep->dentry.file.modify_time, 170 &ep->dentry.file.modify_date, 171 &ep->dentry.file.modify_time_cs); 172 ep->dentry.file.attr = cpu_to_le16(ei->attr); 173 174 /* File size should be zero if there is no cluster allocated */ 175 if (ei->start_clu == EXFAT_EOF_CLUSTER) { 176 ep2->dentry.stream.valid_size = 0; 177 ep2->dentry.stream.size = 0; 178 } else { 179 ep2->dentry.stream.valid_size = cpu_to_le64(new_size); 180 ep2->dentry.stream.size = ep2->dentry.stream.valid_size; 181 } 182 183 if (new_size == 0) { 184 /* Any directory can not be truncated to zero */ 185 WARN_ON(ei->type != TYPE_FILE); 186 187 ep2->dentry.stream.flags = ALLOC_FAT_CHAIN; 188 ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER; 189 } 190 191 exfat_update_dir_chksum_with_entry_set(es); 192 err = exfat_free_dentry_set(es, inode_needs_sync(inode)); 193 if (err) 194 return err; 195 } 196 197 /* cut off from the FAT chain */ 198 if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER && 199 last_clu != EXFAT_EOF_CLUSTER) { 200 if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER)) 201 return -EIO; 202 } 203 204 /* invalidate cache and free the clusters */ 205 /* clear exfat cache */ 206 exfat_cache_inval_inode(inode); 207 208 /* hint information */ 209 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 210 ei->hint_bmap.clu = EXFAT_EOF_CLUSTER; 211 212 /* hint_stat will be used if this is directory. */ 213 ei->hint_stat.eidx = 0; 214 ei->hint_stat.clu = ei->start_clu; 215 ei->hint_femp.eidx = EXFAT_HINT_NONE; 216 217 /* free the clusters */ 218 if (exfat_free_cluster(inode, &clu)) 219 return -EIO; 220 221 exfat_clear_volume_dirty(sb); 222 223 return 0; 224 } 225 226 void exfat_truncate(struct inode *inode, loff_t size) 227 { 228 struct super_block *sb = inode->i_sb; 229 struct exfat_sb_info *sbi = EXFAT_SB(sb); 230 struct exfat_inode_info *ei = EXFAT_I(inode); 231 unsigned int blocksize = i_blocksize(inode); 232 loff_t aligned_size; 233 int err; 234 235 mutex_lock(&sbi->s_lock); 236 if (ei->start_clu == 0) { 237 /* 238 * Empty start_clu != ~0 (not allocated) 239 */ 240 exfat_fs_error(sb, "tried to truncate zeroed cluster."); 241 goto write_size; 242 } 243 244 err = __exfat_truncate(inode, i_size_read(inode)); 245 if (err) 246 goto write_size; 247 248 inode->i_ctime = inode->i_mtime = current_time(inode); 249 if (IS_DIRSYNC(inode)) 250 exfat_sync_inode(inode); 251 else 252 mark_inode_dirty(inode); 253 254 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 255 inode->i_blkbits; 256 write_size: 257 aligned_size = i_size_read(inode); 258 if (aligned_size & (blocksize - 1)) { 259 aligned_size |= (blocksize - 1); 260 aligned_size++; 261 } 262 263 if (ei->i_size_ondisk > i_size_read(inode)) 264 ei->i_size_ondisk = aligned_size; 265 266 if (ei->i_size_aligned > i_size_read(inode)) 267 ei->i_size_aligned = aligned_size; 268 mutex_unlock(&sbi->s_lock); 269 } 270 271 int exfat_getattr(struct user_namespace *mnt_uerns, const struct path *path, 272 struct kstat *stat, unsigned int request_mask, 273 unsigned int query_flags) 274 { 275 struct inode *inode = d_backing_inode(path->dentry); 276 struct exfat_inode_info *ei = EXFAT_I(inode); 277 278 generic_fillattr(&init_user_ns, inode, stat); 279 exfat_truncate_atime(&stat->atime); 280 stat->result_mask |= STATX_BTIME; 281 stat->btime.tv_sec = ei->i_crtime.tv_sec; 282 stat->btime.tv_nsec = ei->i_crtime.tv_nsec; 283 stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size; 284 return 0; 285 } 286 287 int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, 288 struct iattr *attr) 289 { 290 struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb); 291 struct inode *inode = dentry->d_inode; 292 unsigned int ia_valid; 293 int error; 294 295 if ((attr->ia_valid & ATTR_SIZE) && 296 attr->ia_size > i_size_read(inode)) { 297 error = exfat_cont_expand(inode, attr->ia_size); 298 if (error || attr->ia_valid == ATTR_SIZE) 299 return error; 300 attr->ia_valid &= ~ATTR_SIZE; 301 } 302 303 /* Check for setting the inode time. */ 304 ia_valid = attr->ia_valid; 305 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) && 306 exfat_allow_set_time(sbi, inode)) { 307 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET | 308 ATTR_TIMES_SET); 309 } 310 311 error = setattr_prepare(&init_user_ns, dentry, attr); 312 attr->ia_valid = ia_valid; 313 if (error) 314 goto out; 315 316 if (((attr->ia_valid & ATTR_UID) && 317 !uid_eq(attr->ia_uid, sbi->options.fs_uid)) || 318 ((attr->ia_valid & ATTR_GID) && 319 !gid_eq(attr->ia_gid, sbi->options.fs_gid)) || 320 ((attr->ia_valid & ATTR_MODE) && 321 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) { 322 error = -EPERM; 323 goto out; 324 } 325 326 /* 327 * We don't return -EPERM here. Yes, strange, but this is too 328 * old behavior. 329 */ 330 if (attr->ia_valid & ATTR_MODE) { 331 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0) 332 attr->ia_valid &= ~ATTR_MODE; 333 } 334 335 if (attr->ia_valid & ATTR_SIZE) { 336 error = exfat_block_truncate_page(inode, attr->ia_size); 337 if (error) 338 goto out; 339 340 down_write(&EXFAT_I(inode)->truncate_lock); 341 truncate_setsize(inode, attr->ia_size); 342 exfat_truncate(inode, attr->ia_size); 343 up_write(&EXFAT_I(inode)->truncate_lock); 344 } 345 346 setattr_copy(&init_user_ns, inode, attr); 347 exfat_truncate_atime(&inode->i_atime); 348 mark_inode_dirty(inode); 349 350 out: 351 return error; 352 } 353 354 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg) 355 { 356 struct request_queue *q = bdev_get_queue(inode->i_sb->s_bdev); 357 struct fstrim_range range; 358 int ret = 0; 359 360 if (!capable(CAP_SYS_ADMIN)) 361 return -EPERM; 362 363 if (!blk_queue_discard(q)) 364 return -EOPNOTSUPP; 365 366 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range))) 367 return -EFAULT; 368 369 range.minlen = max_t(unsigned int, range.minlen, 370 q->limits.discard_granularity); 371 372 ret = exfat_trim_fs(inode, &range); 373 if (ret < 0) 374 return ret; 375 376 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range))) 377 return -EFAULT; 378 379 return 0; 380 } 381 382 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 383 { 384 struct inode *inode = file_inode(filp); 385 386 switch (cmd) { 387 case FITRIM: 388 return exfat_ioctl_fitrim(inode, arg); 389 default: 390 return -ENOTTY; 391 } 392 } 393 394 #ifdef CONFIG_COMPAT 395 long exfat_compat_ioctl(struct file *filp, unsigned int cmd, 396 unsigned long arg) 397 { 398 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); 399 } 400 #endif 401 402 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) 403 { 404 struct inode *inode = filp->f_mapping->host; 405 int err; 406 407 err = __generic_file_fsync(filp, start, end, datasync); 408 if (err) 409 return err; 410 411 err = sync_blockdev(inode->i_sb->s_bdev); 412 if (err) 413 return err; 414 415 return blkdev_issue_flush(inode->i_sb->s_bdev); 416 } 417 418 const struct file_operations exfat_file_operations = { 419 .llseek = generic_file_llseek, 420 .read_iter = generic_file_read_iter, 421 .write_iter = generic_file_write_iter, 422 .unlocked_ioctl = exfat_ioctl, 423 #ifdef CONFIG_COMPAT 424 .compat_ioctl = exfat_compat_ioctl, 425 #endif 426 .mmap = generic_file_mmap, 427 .fsync = exfat_file_fsync, 428 .splice_read = generic_file_splice_read, 429 .splice_write = iter_file_splice_write, 430 }; 431 432 const struct inode_operations exfat_file_inode_operations = { 433 .setattr = exfat_setattr, 434 .getattr = exfat_getattr, 435 }; 436