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 #include <linux/fsnotify.h> 12 #include <linux/security.h> 13 #include <linux/msdos_fs.h> 14 #include <linux/writeback.h> 15 #include <linux/filelock.h> 16 17 #include "exfat_raw.h" 18 #include "exfat_fs.h" 19 20 static int exfat_cont_expand(struct inode *inode, loff_t size) 21 { 22 int ret; 23 unsigned int num_clusters, new_num_clusters, last_clu; 24 struct exfat_inode_info *ei = EXFAT_I(inode); 25 struct super_block *sb = inode->i_sb; 26 struct exfat_sb_info *sbi = EXFAT_SB(sb); 27 struct exfat_chain clu; 28 29 truncate_pagecache(inode, i_size_read(inode)); 30 31 ret = inode_newsize_ok(inode, size); 32 if (ret) 33 return ret; 34 35 num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi); 36 new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi); 37 38 if (new_num_clusters == num_clusters) 39 goto out; 40 41 if (num_clusters) { 42 exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags); 43 ret = exfat_find_last_cluster(sb, &clu, &last_clu); 44 if (ret) 45 return ret; 46 47 clu.dir = last_clu + 1; 48 } else { 49 last_clu = EXFAT_EOF_CLUSTER; 50 clu.dir = EXFAT_EOF_CLUSTER; 51 } 52 53 clu.size = 0; 54 clu.flags = ei->flags; 55 56 ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters, 57 &clu, inode_needs_sync(inode)); 58 if (ret) 59 return ret; 60 61 /* Append new clusters to chain */ 62 if (num_clusters) { 63 if (clu.flags != ei->flags) 64 if (exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters)) 65 goto free_clu; 66 67 if (clu.flags == ALLOC_FAT_CHAIN) 68 if (exfat_ent_set(sb, last_clu, clu.dir)) 69 goto free_clu; 70 } else 71 ei->start_clu = clu.dir; 72 73 ei->flags = clu.flags; 74 75 out: 76 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); 77 /* Expanded range not zeroed, do not update valid_size */ 78 i_size_write(inode, size); 79 80 inode->i_blocks = round_up(size, sbi->cluster_size) >> 9; 81 mark_inode_dirty(inode); 82 83 if (IS_SYNC(inode)) 84 return write_inode_now(inode, 1); 85 86 return 0; 87 88 free_clu: 89 exfat_free_cluster(inode, &clu); 90 return -EIO; 91 } 92 93 static bool exfat_allow_set_time(struct mnt_idmap *idmap, 94 struct exfat_sb_info *sbi, struct inode *inode) 95 { 96 mode_t allow_utime = sbi->options.allow_utime; 97 98 if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode), 99 current_fsuid())) { 100 if (vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode))) 101 allow_utime >>= 3; 102 if (allow_utime & MAY_WRITE) 103 return true; 104 } 105 106 /* use a default check */ 107 return false; 108 } 109 110 static int exfat_sanitize_mode(const struct exfat_sb_info *sbi, 111 struct inode *inode, umode_t *mode_ptr) 112 { 113 mode_t i_mode, mask, perm; 114 115 i_mode = inode->i_mode; 116 117 mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ? 118 sbi->options.fs_fmask : sbi->options.fs_dmask; 119 perm = *mode_ptr & ~(S_IFMT | mask); 120 121 /* Of the r and x bits, all (subject to umask) must be present.*/ 122 if ((perm & 0555) != (i_mode & 0555)) 123 return -EPERM; 124 125 if (exfat_mode_can_hold_ro(inode)) { 126 /* 127 * Of the w bits, either all (subject to umask) or none must 128 * be present. 129 */ 130 if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask))) 131 return -EPERM; 132 } else { 133 /* 134 * If exfat_mode_can_hold_ro(inode) is false, can't change 135 * w bits. 136 */ 137 if ((perm & 0222) != (0222 & ~mask)) 138 return -EPERM; 139 } 140 141 *mode_ptr &= S_IFMT | perm; 142 143 return 0; 144 } 145 146 /* resize the file length */ 147 int __exfat_truncate(struct inode *inode) 148 { 149 unsigned int num_clusters_new, num_clusters_phys; 150 unsigned int last_clu = EXFAT_FREE_CLUSTER; 151 struct exfat_chain clu; 152 struct super_block *sb = inode->i_sb; 153 struct exfat_sb_info *sbi = EXFAT_SB(sb); 154 struct exfat_inode_info *ei = EXFAT_I(inode); 155 156 /* check if the given file ID is opened */ 157 if (ei->type != TYPE_FILE && ei->type != TYPE_DIR) 158 return -EPERM; 159 160 exfat_set_volume_dirty(sb); 161 162 num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi); 163 num_clusters_phys = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi); 164 165 exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags); 166 167 if (i_size_read(inode) > 0) { 168 /* 169 * Truncate FAT chain num_clusters after the first cluster 170 * num_clusters = min(new, phys); 171 */ 172 unsigned int num_clusters = 173 min(num_clusters_new, num_clusters_phys); 174 175 /* 176 * Follow FAT chain 177 * (defensive coding - works fine even with corrupted FAT table 178 */ 179 if (clu.flags == ALLOC_NO_FAT_CHAIN) { 180 clu.dir += num_clusters; 181 clu.size -= num_clusters; 182 } else { 183 while (num_clusters > 0) { 184 last_clu = clu.dir; 185 if (exfat_get_next_cluster(sb, &(clu.dir))) 186 return -EIO; 187 188 num_clusters--; 189 clu.size--; 190 } 191 } 192 } else { 193 ei->flags = ALLOC_NO_FAT_CHAIN; 194 ei->start_clu = EXFAT_EOF_CLUSTER; 195 } 196 197 if (i_size_read(inode) < ei->valid_size) 198 ei->valid_size = i_size_read(inode); 199 200 if (ei->type == TYPE_FILE) 201 ei->attr |= EXFAT_ATTR_ARCHIVE; 202 203 /* 204 * update the directory entry 205 * 206 * If the directory entry is updated by mark_inode_dirty(), the 207 * directory entry will be written after a writeback cycle of 208 * updating the bitmap/FAT, which may result in clusters being 209 * freed but referenced by the directory entry in the event of a 210 * sudden power failure. 211 * __exfat_write_inode() is called for directory entry, bitmap 212 * and FAT to be written in a same writeback. 213 */ 214 if (__exfat_write_inode(inode, inode_needs_sync(inode))) 215 return -EIO; 216 217 /* cut off from the FAT chain */ 218 if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER && 219 last_clu != EXFAT_EOF_CLUSTER) { 220 if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER)) 221 return -EIO; 222 } 223 224 /* invalidate cache and free the clusters */ 225 /* clear exfat cache */ 226 exfat_cache_inval_inode(inode); 227 228 /* hint information */ 229 ei->hint_bmap.off = EXFAT_EOF_CLUSTER; 230 ei->hint_bmap.clu = EXFAT_EOF_CLUSTER; 231 232 /* hint_stat will be used if this is directory. */ 233 ei->hint_stat.eidx = 0; 234 ei->hint_stat.clu = ei->start_clu; 235 ei->hint_femp.eidx = EXFAT_HINT_NONE; 236 237 /* free the clusters */ 238 if (exfat_free_cluster(inode, &clu)) 239 return -EIO; 240 241 return 0; 242 } 243 244 void exfat_truncate(struct inode *inode) 245 { 246 struct super_block *sb = inode->i_sb; 247 struct exfat_sb_info *sbi = EXFAT_SB(sb); 248 struct exfat_inode_info *ei = EXFAT_I(inode); 249 int err; 250 251 mutex_lock(&sbi->s_lock); 252 if (ei->start_clu == 0) { 253 /* 254 * Empty start_clu != ~0 (not allocated) 255 */ 256 exfat_fs_error(sb, "tried to truncate zeroed cluster."); 257 goto write_size; 258 } 259 260 err = __exfat_truncate(inode); 261 if (err) 262 goto write_size; 263 264 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9; 265 write_size: 266 mutex_unlock(&sbi->s_lock); 267 } 268 269 int exfat_getattr(struct mnt_idmap *idmap, 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(idmap, request_mask, 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 mnt_idmap *idmap, 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 (unlikely(exfat_forced_shutdown(inode->i_sb))) 294 return -EIO; 295 296 if ((attr->ia_valid & ATTR_SIZE) && 297 attr->ia_size > i_size_read(inode)) { 298 error = exfat_cont_expand(inode, attr->ia_size); 299 if (error || attr->ia_valid == ATTR_SIZE) 300 return error; 301 attr->ia_valid &= ~ATTR_SIZE; 302 } 303 304 /* Check for setting the inode time. */ 305 ia_valid = attr->ia_valid; 306 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) && 307 exfat_allow_set_time(idmap, sbi, inode)) { 308 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET | 309 ATTR_TIMES_SET); 310 } 311 312 error = setattr_prepare(idmap, dentry, attr); 313 attr->ia_valid = ia_valid; 314 if (error) 315 goto out; 316 317 if (((attr->ia_valid & ATTR_UID) && 318 (!uid_eq(from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid), 319 sbi->options.fs_uid))) || 320 ((attr->ia_valid & ATTR_GID) && 321 (!gid_eq(from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid), 322 sbi->options.fs_gid))) || 323 ((attr->ia_valid & ATTR_MODE) && 324 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) { 325 error = -EPERM; 326 goto out; 327 } 328 329 /* 330 * We don't return -EPERM here. Yes, strange, but this is too 331 * old behavior. 332 */ 333 if (attr->ia_valid & ATTR_MODE) { 334 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0) 335 attr->ia_valid &= ~ATTR_MODE; 336 } 337 338 if (attr->ia_valid & ATTR_SIZE) 339 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); 340 341 setattr_copy(idmap, inode, attr); 342 exfat_truncate_inode_atime(inode); 343 344 if (attr->ia_valid & ATTR_SIZE) { 345 error = exfat_block_truncate_page(inode, attr->ia_size); 346 if (error) 347 goto out; 348 349 down_write(&EXFAT_I(inode)->truncate_lock); 350 truncate_setsize(inode, attr->ia_size); 351 352 /* 353 * __exfat_write_inode() is called from exfat_truncate(), inode 354 * is already written by it, so mark_inode_dirty() is unneeded. 355 */ 356 exfat_truncate(inode); 357 up_write(&EXFAT_I(inode)->truncate_lock); 358 } else 359 mark_inode_dirty(inode); 360 361 out: 362 return error; 363 } 364 365 /* 366 * modified ioctls from fat/file.c by Welmer Almesberger 367 */ 368 static int exfat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr) 369 { 370 u32 attr; 371 372 inode_lock_shared(inode); 373 attr = exfat_make_attr(inode); 374 inode_unlock_shared(inode); 375 376 return put_user(attr, user_attr); 377 } 378 379 static int exfat_ioctl_set_attributes(struct file *file, u32 __user *user_attr) 380 { 381 struct inode *inode = file_inode(file); 382 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); 383 int is_dir = S_ISDIR(inode->i_mode); 384 u32 attr, oldattr; 385 struct iattr ia; 386 int err; 387 388 err = get_user(attr, user_attr); 389 if (err) 390 goto out; 391 392 err = mnt_want_write_file(file); 393 if (err) 394 goto out; 395 inode_lock(inode); 396 397 oldattr = exfat_make_attr(inode); 398 399 /* 400 * Mask attributes so we don't set reserved fields. 401 */ 402 attr &= (EXFAT_ATTR_READONLY | EXFAT_ATTR_HIDDEN | EXFAT_ATTR_SYSTEM | 403 EXFAT_ATTR_ARCHIVE); 404 attr |= (is_dir ? EXFAT_ATTR_SUBDIR : 0); 405 406 /* Equivalent to a chmod() */ 407 ia.ia_valid = ATTR_MODE | ATTR_CTIME; 408 ia.ia_ctime = current_time(inode); 409 if (is_dir) 410 ia.ia_mode = exfat_make_mode(sbi, attr, 0777); 411 else 412 ia.ia_mode = exfat_make_mode(sbi, attr, 0666 | (inode->i_mode & 0111)); 413 414 /* The root directory has no attributes */ 415 if (inode->i_ino == EXFAT_ROOT_INO && attr != EXFAT_ATTR_SUBDIR) { 416 err = -EINVAL; 417 goto out_unlock_inode; 418 } 419 420 if (((attr | oldattr) & EXFAT_ATTR_SYSTEM) && 421 !capable(CAP_LINUX_IMMUTABLE)) { 422 err = -EPERM; 423 goto out_unlock_inode; 424 } 425 426 /* 427 * The security check is questionable... We single 428 * out the RO attribute for checking by the security 429 * module, just because it maps to a file mode. 430 */ 431 err = security_inode_setattr(file_mnt_idmap(file), 432 file->f_path.dentry, &ia); 433 if (err) 434 goto out_unlock_inode; 435 436 /* This MUST be done before doing anything irreversible... */ 437 err = exfat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia); 438 if (err) 439 goto out_unlock_inode; 440 441 fsnotify_change(file->f_path.dentry, ia.ia_valid); 442 443 exfat_save_attr(inode, attr); 444 mark_inode_dirty(inode); 445 out_unlock_inode: 446 inode_unlock(inode); 447 mnt_drop_write_file(file); 448 out: 449 return err; 450 } 451 452 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg) 453 { 454 struct fstrim_range range; 455 int ret = 0; 456 457 if (!capable(CAP_SYS_ADMIN)) 458 return -EPERM; 459 460 if (!bdev_max_discard_sectors(inode->i_sb->s_bdev)) 461 return -EOPNOTSUPP; 462 463 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range))) 464 return -EFAULT; 465 466 range.minlen = max_t(unsigned int, range.minlen, 467 bdev_discard_granularity(inode->i_sb->s_bdev)); 468 469 ret = exfat_trim_fs(inode, &range); 470 if (ret < 0) 471 return ret; 472 473 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range))) 474 return -EFAULT; 475 476 return 0; 477 } 478 479 static int exfat_ioctl_shutdown(struct super_block *sb, unsigned long arg) 480 { 481 u32 flags; 482 483 if (!capable(CAP_SYS_ADMIN)) 484 return -EPERM; 485 486 if (get_user(flags, (__u32 __user *)arg)) 487 return -EFAULT; 488 489 return exfat_force_shutdown(sb, flags); 490 } 491 492 static int exfat_ioctl_get_volume_label(struct super_block *sb, unsigned long arg) 493 { 494 int ret; 495 char label[FSLABEL_MAX] = {0}; 496 struct exfat_uni_name uniname; 497 498 ret = exfat_read_volume_label(sb, &uniname); 499 if (ret < 0) 500 return ret; 501 502 ret = exfat_utf16_to_nls(sb, &uniname, label, uniname.name_len); 503 if (ret < 0) 504 return ret; 505 506 if (copy_to_user((char __user *)arg, label, ret + 1)) 507 return -EFAULT; 508 509 return 0; 510 } 511 512 static int exfat_ioctl_set_volume_label(struct super_block *sb, 513 unsigned long arg) 514 { 515 int ret = 0, lossy, label_len; 516 char label[FSLABEL_MAX] = {0}; 517 struct exfat_uni_name uniname; 518 519 if (!capable(CAP_SYS_ADMIN)) 520 return -EPERM; 521 522 if (copy_from_user(label, (char __user *)arg, FSLABEL_MAX)) 523 return -EFAULT; 524 525 memset(&uniname, 0, sizeof(uniname)); 526 label_len = strnlen(label, FSLABEL_MAX - 1); 527 if (label[0]) { 528 ret = exfat_nls_to_utf16(sb, label, label_len, 529 &uniname, &lossy); 530 if (ret < 0) 531 return ret; 532 else if (lossy & NLS_NAME_LOSSY) 533 return -EINVAL; 534 } 535 536 uniname.name_len = ret; 537 538 return exfat_write_volume_label(sb, &uniname); 539 } 540 541 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 542 { 543 struct inode *inode = file_inode(filp); 544 u32 __user *user_attr = (u32 __user *)arg; 545 546 switch (cmd) { 547 case FAT_IOCTL_GET_ATTRIBUTES: 548 return exfat_ioctl_get_attributes(inode, user_attr); 549 case FAT_IOCTL_SET_ATTRIBUTES: 550 return exfat_ioctl_set_attributes(filp, user_attr); 551 case EXFAT_IOC_SHUTDOWN: 552 return exfat_ioctl_shutdown(inode->i_sb, arg); 553 case FITRIM: 554 return exfat_ioctl_fitrim(inode, arg); 555 case FS_IOC_GETFSLABEL: 556 return exfat_ioctl_get_volume_label(inode->i_sb, arg); 557 case FS_IOC_SETFSLABEL: 558 return exfat_ioctl_set_volume_label(inode->i_sb, arg); 559 default: 560 return -ENOTTY; 561 } 562 } 563 564 #ifdef CONFIG_COMPAT 565 long exfat_compat_ioctl(struct file *filp, unsigned int cmd, 566 unsigned long arg) 567 { 568 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); 569 } 570 #endif 571 572 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) 573 { 574 struct inode *inode = filp->f_mapping->host; 575 int err; 576 577 if (unlikely(exfat_forced_shutdown(inode->i_sb))) 578 return -EIO; 579 580 err = __generic_file_fsync(filp, start, end, datasync); 581 if (err) 582 return err; 583 584 err = sync_blockdev(inode->i_sb->s_bdev); 585 if (err) 586 return err; 587 588 return blkdev_issue_flush(inode->i_sb->s_bdev); 589 } 590 591 static int exfat_extend_valid_size(struct inode *inode, loff_t new_valid_size) 592 { 593 int err; 594 loff_t pos; 595 struct exfat_inode_info *ei = EXFAT_I(inode); 596 struct address_space *mapping = inode->i_mapping; 597 const struct address_space_operations *ops = mapping->a_ops; 598 599 pos = ei->valid_size; 600 while (pos < new_valid_size) { 601 u32 len; 602 struct folio *folio; 603 unsigned long off; 604 605 len = PAGE_SIZE - (pos & (PAGE_SIZE - 1)); 606 if (pos + len > new_valid_size) 607 len = new_valid_size - pos; 608 609 err = ops->write_begin(NULL, mapping, pos, len, &folio, NULL); 610 if (err) 611 goto out; 612 613 off = offset_in_folio(folio, pos); 614 folio_zero_new_buffers(folio, off, off + len); 615 616 err = ops->write_end(NULL, mapping, pos, len, len, folio, NULL); 617 if (err < 0) 618 goto out; 619 pos += len; 620 621 balance_dirty_pages_ratelimited(mapping); 622 cond_resched(); 623 } 624 625 return 0; 626 627 out: 628 return err; 629 } 630 631 static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter) 632 { 633 ssize_t ret; 634 struct file *file = iocb->ki_filp; 635 struct inode *inode = file_inode(file); 636 struct exfat_inode_info *ei = EXFAT_I(inode); 637 loff_t pos = iocb->ki_pos; 638 loff_t valid_size; 639 640 if (unlikely(exfat_forced_shutdown(inode->i_sb))) 641 return -EIO; 642 643 inode_lock(inode); 644 645 if (pos > i_size_read(inode)) 646 truncate_pagecache(inode, i_size_read(inode)); 647 648 valid_size = ei->valid_size; 649 650 ret = generic_write_checks(iocb, iter); 651 if (ret <= 0) 652 goto unlock; 653 654 if (iocb->ki_flags & IOCB_DIRECT) { 655 unsigned long align = pos | iov_iter_alignment(iter); 656 657 if (!IS_ALIGNED(align, i_blocksize(inode)) && 658 !IS_ALIGNED(align, bdev_logical_block_size(inode->i_sb->s_bdev))) { 659 ret = -EINVAL; 660 goto unlock; 661 } 662 } 663 664 if (pos > valid_size) { 665 ret = exfat_extend_valid_size(inode, pos); 666 if (ret < 0 && ret != -ENOSPC) { 667 exfat_err(inode->i_sb, 668 "write: fail to zero from %llu to %llu(%zd)", 669 valid_size, pos, ret); 670 } 671 if (ret < 0) 672 goto unlock; 673 } 674 675 ret = __generic_file_write_iter(iocb, iter); 676 if (ret < 0) 677 goto unlock; 678 679 inode_unlock(inode); 680 681 if (pos > valid_size) 682 pos = valid_size; 683 684 if (iocb->ki_pos > pos) { 685 ssize_t err = generic_write_sync(iocb, iocb->ki_pos - pos); 686 if (err < 0) 687 return err; 688 } 689 690 return ret; 691 692 unlock: 693 inode_unlock(inode); 694 695 return ret; 696 } 697 698 static ssize_t exfat_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) 699 { 700 struct inode *inode = file_inode(iocb->ki_filp); 701 702 if (unlikely(exfat_forced_shutdown(inode->i_sb))) 703 return -EIO; 704 705 return generic_file_read_iter(iocb, iter); 706 } 707 708 static vm_fault_t exfat_page_mkwrite(struct vm_fault *vmf) 709 { 710 int err; 711 struct vm_area_struct *vma = vmf->vma; 712 struct file *file = vma->vm_file; 713 struct inode *inode = file_inode(file); 714 struct exfat_inode_info *ei = EXFAT_I(inode); 715 loff_t start, end; 716 717 if (!inode_trylock(inode)) 718 return VM_FAULT_RETRY; 719 720 start = ((loff_t)vma->vm_pgoff << PAGE_SHIFT); 721 end = min_t(loff_t, i_size_read(inode), 722 start + vma->vm_end - vma->vm_start); 723 724 if (ei->valid_size < end) { 725 err = exfat_extend_valid_size(inode, end); 726 if (err < 0) { 727 inode_unlock(inode); 728 return vmf_fs_error(err); 729 } 730 } 731 732 inode_unlock(inode); 733 734 return filemap_page_mkwrite(vmf); 735 } 736 737 static const struct vm_operations_struct exfat_file_vm_ops = { 738 .fault = filemap_fault, 739 .map_pages = filemap_map_pages, 740 .page_mkwrite = exfat_page_mkwrite, 741 }; 742 743 static int exfat_file_mmap_prepare(struct vm_area_desc *desc) 744 { 745 struct file *file = desc->file; 746 747 if (unlikely(exfat_forced_shutdown(file_inode(desc->file)->i_sb))) 748 return -EIO; 749 750 file_accessed(file); 751 desc->vm_ops = &exfat_file_vm_ops; 752 return 0; 753 } 754 755 static ssize_t exfat_splice_read(struct file *in, loff_t *ppos, 756 struct pipe_inode_info *pipe, size_t len, unsigned int flags) 757 { 758 if (unlikely(exfat_forced_shutdown(file_inode(in)->i_sb))) 759 return -EIO; 760 761 return filemap_splice_read(in, ppos, pipe, len, flags); 762 } 763 764 const struct file_operations exfat_file_operations = { 765 .llseek = generic_file_llseek, 766 .read_iter = exfat_file_read_iter, 767 .write_iter = exfat_file_write_iter, 768 .unlocked_ioctl = exfat_ioctl, 769 #ifdef CONFIG_COMPAT 770 .compat_ioctl = exfat_compat_ioctl, 771 #endif 772 .mmap_prepare = exfat_file_mmap_prepare, 773 .fsync = exfat_file_fsync, 774 .splice_read = exfat_splice_read, 775 .splice_write = iter_file_splice_write, 776 .setlease = generic_setlease, 777 }; 778 779 const struct inode_operations exfat_file_inode_operations = { 780 .setattr = exfat_setattr, 781 .getattr = exfat_getattr, 782 }; 783