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 return 0; 222 } 223 224 void exfat_truncate(struct inode *inode, loff_t size) 225 { 226 struct super_block *sb = inode->i_sb; 227 struct exfat_sb_info *sbi = EXFAT_SB(sb); 228 struct exfat_inode_info *ei = EXFAT_I(inode); 229 unsigned int blocksize = i_blocksize(inode); 230 loff_t aligned_size; 231 int err; 232 233 mutex_lock(&sbi->s_lock); 234 if (ei->start_clu == 0) { 235 /* 236 * Empty start_clu != ~0 (not allocated) 237 */ 238 exfat_fs_error(sb, "tried to truncate zeroed cluster."); 239 goto write_size; 240 } 241 242 err = __exfat_truncate(inode, i_size_read(inode)); 243 if (err) 244 goto write_size; 245 246 inode->i_ctime = inode->i_mtime = current_time(inode); 247 if (IS_DIRSYNC(inode)) 248 exfat_sync_inode(inode); 249 else 250 mark_inode_dirty(inode); 251 252 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 253 inode->i_blkbits; 254 write_size: 255 aligned_size = i_size_read(inode); 256 if (aligned_size & (blocksize - 1)) { 257 aligned_size |= (blocksize - 1); 258 aligned_size++; 259 } 260 261 if (ei->i_size_ondisk > i_size_read(inode)) 262 ei->i_size_ondisk = aligned_size; 263 264 if (ei->i_size_aligned > i_size_read(inode)) 265 ei->i_size_aligned = aligned_size; 266 mutex_unlock(&sbi->s_lock); 267 } 268 269 int exfat_getattr(struct user_namespace *mnt_uerns, const struct path *path, 270 struct kstat *stat, unsigned int request_mask, 271 unsigned int query_flags) 272 { 273 struct inode *inode = d_backing_inode(path->dentry); 274 struct exfat_inode_info *ei = EXFAT_I(inode); 275 276 generic_fillattr(&init_user_ns, inode, stat); 277 exfat_truncate_atime(&stat->atime); 278 stat->result_mask |= STATX_BTIME; 279 stat->btime.tv_sec = ei->i_crtime.tv_sec; 280 stat->btime.tv_nsec = ei->i_crtime.tv_nsec; 281 stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size; 282 return 0; 283 } 284 285 int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, 286 struct iattr *attr) 287 { 288 struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb); 289 struct inode *inode = dentry->d_inode; 290 unsigned int ia_valid; 291 int error; 292 293 if ((attr->ia_valid & ATTR_SIZE) && 294 attr->ia_size > i_size_read(inode)) { 295 error = exfat_cont_expand(inode, attr->ia_size); 296 if (error || attr->ia_valid == ATTR_SIZE) 297 return error; 298 attr->ia_valid &= ~ATTR_SIZE; 299 } 300 301 /* Check for setting the inode time. */ 302 ia_valid = attr->ia_valid; 303 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) && 304 exfat_allow_set_time(sbi, inode)) { 305 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET | 306 ATTR_TIMES_SET); 307 } 308 309 error = setattr_prepare(&init_user_ns, dentry, attr); 310 attr->ia_valid = ia_valid; 311 if (error) 312 goto out; 313 314 if (((attr->ia_valid & ATTR_UID) && 315 !uid_eq(attr->ia_uid, sbi->options.fs_uid)) || 316 ((attr->ia_valid & ATTR_GID) && 317 !gid_eq(attr->ia_gid, sbi->options.fs_gid)) || 318 ((attr->ia_valid & ATTR_MODE) && 319 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) { 320 error = -EPERM; 321 goto out; 322 } 323 324 /* 325 * We don't return -EPERM here. Yes, strange, but this is too 326 * old behavior. 327 */ 328 if (attr->ia_valid & ATTR_MODE) { 329 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0) 330 attr->ia_valid &= ~ATTR_MODE; 331 } 332 333 if (attr->ia_valid & ATTR_SIZE) { 334 error = exfat_block_truncate_page(inode, attr->ia_size); 335 if (error) 336 goto out; 337 338 down_write(&EXFAT_I(inode)->truncate_lock); 339 truncate_setsize(inode, attr->ia_size); 340 exfat_truncate(inode, attr->ia_size); 341 up_write(&EXFAT_I(inode)->truncate_lock); 342 } 343 344 setattr_copy(&init_user_ns, inode, attr); 345 exfat_truncate_atime(&inode->i_atime); 346 mark_inode_dirty(inode); 347 348 out: 349 return error; 350 } 351 352 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg) 353 { 354 struct request_queue *q = bdev_get_queue(inode->i_sb->s_bdev); 355 struct fstrim_range range; 356 int ret = 0; 357 358 if (!capable(CAP_SYS_ADMIN)) 359 return -EPERM; 360 361 if (!blk_queue_discard(q)) 362 return -EOPNOTSUPP; 363 364 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range))) 365 return -EFAULT; 366 367 range.minlen = max_t(unsigned int, range.minlen, 368 q->limits.discard_granularity); 369 370 ret = exfat_trim_fs(inode, &range); 371 if (ret < 0) 372 return ret; 373 374 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range))) 375 return -EFAULT; 376 377 return 0; 378 } 379 380 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 381 { 382 struct inode *inode = file_inode(filp); 383 384 switch (cmd) { 385 case FITRIM: 386 return exfat_ioctl_fitrim(inode, arg); 387 default: 388 return -ENOTTY; 389 } 390 } 391 392 #ifdef CONFIG_COMPAT 393 long exfat_compat_ioctl(struct file *filp, unsigned int cmd, 394 unsigned long arg) 395 { 396 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); 397 } 398 #endif 399 400 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) 401 { 402 struct inode *inode = filp->f_mapping->host; 403 int err; 404 405 err = __generic_file_fsync(filp, start, end, datasync); 406 if (err) 407 return err; 408 409 err = sync_blockdev(inode->i_sb->s_bdev); 410 if (err) 411 return err; 412 413 return blkdev_issue_flush(inode->i_sb->s_bdev); 414 } 415 416 const struct file_operations exfat_file_operations = { 417 .llseek = generic_file_llseek, 418 .read_iter = generic_file_read_iter, 419 .write_iter = generic_file_write_iter, 420 .unlocked_ioctl = exfat_ioctl, 421 #ifdef CONFIG_COMPAT 422 .compat_ioctl = exfat_compat_ioctl, 423 #endif 424 .mmap = generic_file_mmap, 425 .fsync = exfat_file_fsync, 426 .splice_read = generic_file_splice_read, 427 .splice_write = iter_file_splice_write, 428 }; 429 430 const struct inode_operations exfat_file_inode_operations = { 431 .setattr = exfat_setattr, 432 .getattr = exfat_getattr, 433 }; 434