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 #include <linux/falloc.h>
17
18 #include "exfat_raw.h"
19 #include "exfat_fs.h"
20
exfat_cont_expand(struct inode * inode,loff_t size)21 static int exfat_cont_expand(struct inode *inode, loff_t size)
22 {
23 int ret;
24 unsigned int num_clusters, new_num_clusters, last_clu;
25 struct exfat_inode_info *ei = EXFAT_I(inode);
26 struct super_block *sb = inode->i_sb;
27 struct exfat_sb_info *sbi = EXFAT_SB(sb);
28 struct exfat_chain clu;
29
30 truncate_pagecache(inode, i_size_read(inode));
31
32 ret = inode_newsize_ok(inode, size);
33 if (ret)
34 return ret;
35
36 num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
37 /* integer overflow is already checked in inode_newsize_ok(). */
38 new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi);
39
40 if (new_num_clusters == num_clusters)
41 goto out;
42
43 if (num_clusters) {
44 exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags);
45 ret = exfat_find_last_cluster(sb, &clu, &last_clu);
46 if (ret)
47 return ret;
48
49 clu.dir = last_clu + 1;
50 } else {
51 last_clu = EXFAT_EOF_CLUSTER;
52 clu.dir = EXFAT_EOF_CLUSTER;
53 }
54
55 clu.size = 0;
56 clu.flags = ei->flags;
57
58 ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters,
59 &clu, inode_needs_sync(inode));
60 if (ret)
61 return ret;
62
63 /* Append new clusters to chain */
64 if (num_clusters) {
65 if (clu.flags != ei->flags)
66 if (exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters))
67 goto free_clu;
68
69 if (clu.flags == ALLOC_FAT_CHAIN)
70 if (exfat_ent_set(sb, last_clu, clu.dir))
71 goto free_clu;
72 } else
73 ei->start_clu = clu.dir;
74
75 ei->flags = clu.flags;
76
77 out:
78 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
79 /* Expanded range not zeroed, do not update valid_size */
80 i_size_write(inode, size);
81
82 inode->i_blocks = round_up(size, sbi->cluster_size) >> 9;
83 mark_inode_dirty(inode);
84
85 if (IS_SYNC(inode))
86 return write_inode_now(inode, 1);
87
88 return 0;
89
90 free_clu:
91 exfat_free_cluster(inode, &clu);
92 return -EIO;
93 }
94
95 /*
96 * Preallocate space for a file. This implements exfat's fallocate file
97 * operation, which gets called from sys_fallocate system call. User space
98 * requests len bytes at offset. In contrary to fat, we only support
99 * FALLOC_FL_ALLOCATE_RANGE because by leaving the valid data length(VDL)
100 * field, it is unnecessary to zero out the newly allocated clusters.
101 */
exfat_fallocate(struct file * file,int mode,loff_t offset,loff_t len)102 static long exfat_fallocate(struct file *file, int mode,
103 loff_t offset, loff_t len)
104 {
105 struct inode *inode = file->f_mapping->host;
106 loff_t newsize = offset + len;
107 int err = 0;
108
109 /* No support for other modes */
110 if (mode != FALLOC_FL_ALLOCATE_RANGE)
111 return -EOPNOTSUPP;
112
113 /* No support for dir */
114 if (!S_ISREG(inode->i_mode))
115 return -EOPNOTSUPP;
116
117 if (unlikely(exfat_forced_shutdown(inode->i_sb)))
118 return -EIO;
119
120 inode_lock(inode);
121
122 if (newsize <= i_size_read(inode))
123 goto error;
124
125 /* This is just an expanding truncate */
126 err = exfat_cont_expand(inode, newsize);
127
128 error:
129 inode_unlock(inode);
130
131 return err;
132 }
133
exfat_allow_set_time(struct mnt_idmap * idmap,struct exfat_sb_info * sbi,struct inode * inode)134 static bool exfat_allow_set_time(struct mnt_idmap *idmap,
135 struct exfat_sb_info *sbi, struct inode *inode)
136 {
137 mode_t allow_utime = sbi->options.allow_utime;
138
139 if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode),
140 current_fsuid())) {
141 if (vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))
142 allow_utime >>= 3;
143 if (allow_utime & MAY_WRITE)
144 return true;
145 }
146
147 /* use a default check */
148 return false;
149 }
150
exfat_sanitize_mode(const struct exfat_sb_info * sbi,struct inode * inode,umode_t * mode_ptr)151 static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
152 struct inode *inode, umode_t *mode_ptr)
153 {
154 mode_t i_mode, mask, perm;
155
156 i_mode = inode->i_mode;
157
158 mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?
159 sbi->options.fs_fmask : sbi->options.fs_dmask;
160 perm = *mode_ptr & ~(S_IFMT | mask);
161
162 /* Of the r and x bits, all (subject to umask) must be present.*/
163 if ((perm & 0555) != (i_mode & 0555))
164 return -EPERM;
165
166 if (exfat_mode_can_hold_ro(inode)) {
167 /*
168 * Of the w bits, either all (subject to umask) or none must
169 * be present.
170 */
171 if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
172 return -EPERM;
173 } else {
174 /*
175 * If exfat_mode_can_hold_ro(inode) is false, can't change
176 * w bits.
177 */
178 if ((perm & 0222) != (0222 & ~mask))
179 return -EPERM;
180 }
181
182 *mode_ptr &= S_IFMT | perm;
183
184 return 0;
185 }
186
187 /* resize the file length */
__exfat_truncate(struct inode * inode)188 int __exfat_truncate(struct inode *inode)
189 {
190 unsigned int num_clusters_new, num_clusters_phys;
191 unsigned int last_clu = EXFAT_FREE_CLUSTER;
192 struct exfat_chain clu;
193 struct super_block *sb = inode->i_sb;
194 struct exfat_sb_info *sbi = EXFAT_SB(sb);
195 struct exfat_inode_info *ei = EXFAT_I(inode);
196
197 /* check if the given file ID is opened */
198 if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
199 return -EPERM;
200
201 exfat_set_volume_dirty(sb);
202
203 num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
204 num_clusters_phys = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
205
206 exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
207
208 if (i_size_read(inode) > 0) {
209 /*
210 * Truncate FAT chain num_clusters after the first cluster
211 * num_clusters = min(new, phys);
212 */
213 unsigned int num_clusters =
214 min(num_clusters_new, num_clusters_phys);
215
216 /*
217 * Follow FAT chain
218 * (defensive coding - works fine even with corrupted FAT table
219 */
220 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
221 clu.dir += num_clusters;
222 clu.size -= num_clusters;
223 } else {
224 while (num_clusters > 0) {
225 last_clu = clu.dir;
226 if (exfat_get_next_cluster(sb, &(clu.dir)))
227 return -EIO;
228
229 num_clusters--;
230 clu.size--;
231 }
232 }
233 } else {
234 ei->flags = ALLOC_NO_FAT_CHAIN;
235 ei->start_clu = EXFAT_EOF_CLUSTER;
236 }
237
238 if (i_size_read(inode) < ei->valid_size)
239 ei->valid_size = i_size_read(inode);
240
241 if (ei->type == TYPE_FILE)
242 ei->attr |= EXFAT_ATTR_ARCHIVE;
243
244 /*
245 * update the directory entry
246 *
247 * If the directory entry is updated by mark_inode_dirty(), the
248 * directory entry will be written after a writeback cycle of
249 * updating the bitmap/FAT, which may result in clusters being
250 * freed but referenced by the directory entry in the event of a
251 * sudden power failure.
252 * __exfat_write_inode() is called for directory entry, bitmap
253 * and FAT to be written in a same writeback.
254 */
255 if (__exfat_write_inode(inode, inode_needs_sync(inode)))
256 return -EIO;
257
258 /* cut off from the FAT chain */
259 if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
260 last_clu != EXFAT_EOF_CLUSTER) {
261 if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
262 return -EIO;
263 }
264
265 /* invalidate cache and free the clusters */
266 /* clear exfat cache */
267 exfat_cache_inval_inode(inode);
268
269 /* hint information */
270 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
271 ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
272
273 /* hint_stat will be used if this is directory. */
274 ei->hint_stat.eidx = 0;
275 ei->hint_stat.clu = ei->start_clu;
276 ei->hint_femp.eidx = EXFAT_HINT_NONE;
277
278 /* free the clusters */
279 if (exfat_free_cluster(inode, &clu))
280 return -EIO;
281
282 return 0;
283 }
284
exfat_truncate(struct inode * inode)285 void exfat_truncate(struct inode *inode)
286 {
287 struct super_block *sb = inode->i_sb;
288 struct exfat_sb_info *sbi = EXFAT_SB(sb);
289 struct exfat_inode_info *ei = EXFAT_I(inode);
290 int err;
291
292 mutex_lock(&sbi->s_lock);
293 if (ei->start_clu == 0) {
294 /*
295 * Empty start_clu != ~0 (not allocated)
296 */
297 exfat_fs_error(sb, "tried to truncate zeroed cluster.");
298 goto write_size;
299 }
300
301 err = __exfat_truncate(inode);
302 if (err)
303 goto write_size;
304
305 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
306 write_size:
307 mutex_unlock(&sbi->s_lock);
308 }
309
exfat_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,unsigned int request_mask,unsigned int query_flags)310 int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
311 struct kstat *stat, unsigned int request_mask,
312 unsigned int query_flags)
313 {
314 struct inode *inode = d_backing_inode(path->dentry);
315 struct exfat_inode_info *ei = EXFAT_I(inode);
316
317 generic_fillattr(idmap, request_mask, inode, stat);
318 exfat_truncate_atime(&stat->atime);
319 stat->result_mask |= STATX_BTIME;
320 stat->btime.tv_sec = ei->i_crtime.tv_sec;
321 stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
322 stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
323 return 0;
324 }
325
exfat_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * attr)326 int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
327 struct iattr *attr)
328 {
329 struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
330 struct inode *inode = dentry->d_inode;
331 unsigned int ia_valid;
332 int error;
333
334 if (unlikely(exfat_forced_shutdown(inode->i_sb)))
335 return -EIO;
336
337 if ((attr->ia_valid & ATTR_SIZE) &&
338 attr->ia_size > i_size_read(inode)) {
339 error = exfat_cont_expand(inode, attr->ia_size);
340 if (error || attr->ia_valid == ATTR_SIZE)
341 return error;
342 attr->ia_valid &= ~ATTR_SIZE;
343 }
344
345 /* Check for setting the inode time. */
346 ia_valid = attr->ia_valid;
347 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
348 exfat_allow_set_time(idmap, sbi, inode)) {
349 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
350 ATTR_TIMES_SET);
351 }
352
353 error = setattr_prepare(idmap, dentry, attr);
354 attr->ia_valid = ia_valid;
355 if (error)
356 goto out;
357
358 if (((attr->ia_valid & ATTR_UID) &&
359 (!uid_eq(from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid),
360 sbi->options.fs_uid))) ||
361 ((attr->ia_valid & ATTR_GID) &&
362 (!gid_eq(from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid),
363 sbi->options.fs_gid))) ||
364 ((attr->ia_valid & ATTR_MODE) &&
365 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
366 error = -EPERM;
367 goto out;
368 }
369
370 /*
371 * We don't return -EPERM here. Yes, strange, but this is too
372 * old behavior.
373 */
374 if (attr->ia_valid & ATTR_MODE) {
375 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
376 attr->ia_valid &= ~ATTR_MODE;
377 }
378
379 if (attr->ia_valid & ATTR_SIZE)
380 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
381
382 setattr_copy(idmap, inode, attr);
383 exfat_truncate_inode_atime(inode);
384
385 if (attr->ia_valid & ATTR_SIZE) {
386 error = exfat_block_truncate_page(inode, attr->ia_size);
387 if (error)
388 goto out;
389
390 down_write(&EXFAT_I(inode)->truncate_lock);
391 truncate_setsize(inode, attr->ia_size);
392
393 /*
394 * __exfat_write_inode() is called from exfat_truncate(), inode
395 * is already written by it, so mark_inode_dirty() is unneeded.
396 */
397 exfat_truncate(inode);
398 up_write(&EXFAT_I(inode)->truncate_lock);
399 } else
400 mark_inode_dirty(inode);
401
402 out:
403 return error;
404 }
405
406 /*
407 * modified ioctls from fat/file.c by Welmer Almesberger
408 */
exfat_ioctl_get_attributes(struct inode * inode,u32 __user * user_attr)409 static int exfat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
410 {
411 u32 attr;
412
413 inode_lock_shared(inode);
414 attr = exfat_make_attr(inode);
415 inode_unlock_shared(inode);
416
417 return put_user(attr, user_attr);
418 }
419
exfat_ioctl_set_attributes(struct file * file,u32 __user * user_attr)420 static int exfat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
421 {
422 struct inode *inode = file_inode(file);
423 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
424 int is_dir = S_ISDIR(inode->i_mode);
425 u32 attr, oldattr;
426 struct iattr ia;
427 int err;
428
429 err = get_user(attr, user_attr);
430 if (err)
431 goto out;
432
433 err = mnt_want_write_file(file);
434 if (err)
435 goto out;
436 inode_lock(inode);
437
438 oldattr = exfat_make_attr(inode);
439
440 /*
441 * Mask attributes so we don't set reserved fields.
442 */
443 attr &= (EXFAT_ATTR_READONLY | EXFAT_ATTR_HIDDEN | EXFAT_ATTR_SYSTEM |
444 EXFAT_ATTR_ARCHIVE);
445 attr |= (is_dir ? EXFAT_ATTR_SUBDIR : 0);
446
447 /* Equivalent to a chmod() */
448 ia.ia_valid = ATTR_MODE | ATTR_CTIME;
449 ia.ia_ctime = current_time(inode);
450 if (is_dir)
451 ia.ia_mode = exfat_make_mode(sbi, attr, 0777);
452 else
453 ia.ia_mode = exfat_make_mode(sbi, attr, 0666 | (inode->i_mode & 0111));
454
455 /* The root directory has no attributes */
456 if (inode->i_ino == EXFAT_ROOT_INO && attr != EXFAT_ATTR_SUBDIR) {
457 err = -EINVAL;
458 goto out_unlock_inode;
459 }
460
461 if (((attr | oldattr) & EXFAT_ATTR_SYSTEM) &&
462 !capable(CAP_LINUX_IMMUTABLE)) {
463 err = -EPERM;
464 goto out_unlock_inode;
465 }
466
467 /*
468 * The security check is questionable... We single
469 * out the RO attribute for checking by the security
470 * module, just because it maps to a file mode.
471 */
472 err = security_inode_setattr(file_mnt_idmap(file),
473 file->f_path.dentry, &ia);
474 if (err)
475 goto out_unlock_inode;
476
477 /* This MUST be done before doing anything irreversible... */
478 err = exfat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);
479 if (err)
480 goto out_unlock_inode;
481
482 fsnotify_change(file->f_path.dentry, ia.ia_valid);
483
484 exfat_save_attr(inode, attr);
485 mark_inode_dirty(inode);
486 out_unlock_inode:
487 inode_unlock(inode);
488 mnt_drop_write_file(file);
489 out:
490 return err;
491 }
492
exfat_ioctl_fitrim(struct inode * inode,unsigned long arg)493 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
494 {
495 struct fstrim_range range;
496 int ret = 0;
497
498 if (!capable(CAP_SYS_ADMIN))
499 return -EPERM;
500
501 if (!bdev_max_discard_sectors(inode->i_sb->s_bdev))
502 return -EOPNOTSUPP;
503
504 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))
505 return -EFAULT;
506
507 range.minlen = max_t(unsigned int, range.minlen,
508 bdev_discard_granularity(inode->i_sb->s_bdev));
509
510 ret = exfat_trim_fs(inode, &range);
511 if (ret < 0)
512 return ret;
513
514 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))
515 return -EFAULT;
516
517 return 0;
518 }
519
exfat_ioctl_shutdown(struct super_block * sb,unsigned long arg)520 static int exfat_ioctl_shutdown(struct super_block *sb, unsigned long arg)
521 {
522 u32 flags;
523
524 if (!capable(CAP_SYS_ADMIN))
525 return -EPERM;
526
527 if (get_user(flags, (__u32 __user *)arg))
528 return -EFAULT;
529
530 return exfat_force_shutdown(sb, flags);
531 }
532
exfat_ioctl_get_volume_label(struct super_block * sb,unsigned long arg)533 static int exfat_ioctl_get_volume_label(struct super_block *sb, unsigned long arg)
534 {
535 int ret;
536 char label[FSLABEL_MAX] = {0};
537 struct exfat_uni_name uniname;
538
539 ret = exfat_read_volume_label(sb, &uniname);
540 if (ret < 0)
541 return ret;
542
543 ret = exfat_utf16_to_nls(sb, &uniname, label, uniname.name_len);
544 if (ret < 0)
545 return ret;
546
547 if (copy_to_user((char __user *)arg, label, ret + 1))
548 return -EFAULT;
549
550 return 0;
551 }
552
exfat_ioctl_set_volume_label(struct super_block * sb,unsigned long arg)553 static int exfat_ioctl_set_volume_label(struct super_block *sb,
554 unsigned long arg)
555 {
556 int ret = 0, lossy, label_len;
557 char label[FSLABEL_MAX] = {0};
558 struct exfat_uni_name uniname;
559
560 if (!capable(CAP_SYS_ADMIN))
561 return -EPERM;
562
563 if (copy_from_user(label, (char __user *)arg, FSLABEL_MAX))
564 return -EFAULT;
565
566 memset(&uniname, 0, sizeof(uniname));
567 label_len = strnlen(label, FSLABEL_MAX - 1);
568 if (label[0]) {
569 ret = exfat_nls_to_utf16(sb, label, label_len,
570 &uniname, &lossy);
571 if (ret < 0)
572 return ret;
573 else if (lossy & NLS_NAME_LOSSY)
574 return -EINVAL;
575 }
576
577 uniname.name_len = ret;
578
579 return exfat_write_volume_label(sb, &uniname);
580 }
581
exfat_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)582 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
583 {
584 struct inode *inode = file_inode(filp);
585 u32 __user *user_attr = (u32 __user *)arg;
586
587 switch (cmd) {
588 case FAT_IOCTL_GET_ATTRIBUTES:
589 return exfat_ioctl_get_attributes(inode, user_attr);
590 case FAT_IOCTL_SET_ATTRIBUTES:
591 return exfat_ioctl_set_attributes(filp, user_attr);
592 case EXFAT_IOC_SHUTDOWN:
593 return exfat_ioctl_shutdown(inode->i_sb, arg);
594 case FITRIM:
595 return exfat_ioctl_fitrim(inode, arg);
596 case FS_IOC_GETFSLABEL:
597 return exfat_ioctl_get_volume_label(inode->i_sb, arg);
598 case FS_IOC_SETFSLABEL:
599 return exfat_ioctl_set_volume_label(inode->i_sb, arg);
600 default:
601 return -ENOTTY;
602 }
603 }
604
605 #ifdef CONFIG_COMPAT
exfat_compat_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)606 long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
607 unsigned long arg)
608 {
609 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
610 }
611 #endif
612
exfat_file_fsync(struct file * filp,loff_t start,loff_t end,int datasync)613 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
614 {
615 struct inode *inode = filp->f_mapping->host;
616 int err;
617
618 if (unlikely(exfat_forced_shutdown(inode->i_sb)))
619 return -EIO;
620
621 err = simple_fsync_noflush(filp, start, end, datasync);
622 if (err)
623 return err;
624
625 err = sync_blockdev(inode->i_sb->s_bdev);
626 if (err)
627 return err;
628
629 return blkdev_issue_flush(inode->i_sb->s_bdev);
630 }
631
exfat_extend_valid_size(struct inode * inode,loff_t new_valid_size)632 static int exfat_extend_valid_size(struct inode *inode, loff_t new_valid_size)
633 {
634 int err;
635 loff_t pos;
636 struct exfat_inode_info *ei = EXFAT_I(inode);
637 struct address_space *mapping = inode->i_mapping;
638 const struct address_space_operations *ops = mapping->a_ops;
639
640 pos = ei->valid_size;
641 while (pos < new_valid_size) {
642 u32 len;
643 struct folio *folio;
644 unsigned long off;
645
646 len = PAGE_SIZE - (pos & (PAGE_SIZE - 1));
647 if (pos + len > new_valid_size)
648 len = new_valid_size - pos;
649
650 err = ops->write_begin(NULL, mapping, pos, len, &folio, NULL);
651 if (err)
652 goto out;
653
654 off = offset_in_folio(folio, pos);
655 folio_zero_new_buffers(folio, off, off + len);
656
657 err = ops->write_end(NULL, mapping, pos, len, len, folio, NULL);
658 if (err < 0)
659 goto out;
660 pos += len;
661
662 balance_dirty_pages_ratelimited(mapping);
663 cond_resched();
664 }
665
666 return 0;
667
668 out:
669 return err;
670 }
671
exfat_file_write_iter(struct kiocb * iocb,struct iov_iter * iter)672 static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
673 {
674 ssize_t ret;
675 struct file *file = iocb->ki_filp;
676 struct inode *inode = file_inode(file);
677 struct exfat_inode_info *ei = EXFAT_I(inode);
678 loff_t pos = iocb->ki_pos;
679 loff_t valid_size;
680
681 if (unlikely(exfat_forced_shutdown(inode->i_sb)))
682 return -EIO;
683
684 inode_lock(inode);
685
686 if (pos > i_size_read(inode))
687 truncate_pagecache(inode, i_size_read(inode));
688
689 valid_size = ei->valid_size;
690
691 ret = generic_write_checks(iocb, iter);
692 if (ret <= 0)
693 goto unlock;
694
695 if (iocb->ki_flags & IOCB_DIRECT) {
696 unsigned long align = pos | iov_iter_alignment(iter);
697
698 if (!IS_ALIGNED(align, i_blocksize(inode)) &&
699 !IS_ALIGNED(align, bdev_logical_block_size(inode->i_sb->s_bdev))) {
700 ret = -EINVAL;
701 goto unlock;
702 }
703 }
704
705 if (pos > valid_size) {
706 ret = exfat_extend_valid_size(inode, pos);
707 if (ret < 0 && ret != -ENOSPC) {
708 exfat_err(inode->i_sb,
709 "write: fail to zero from %llu to %llu(%zd)",
710 valid_size, pos, ret);
711 }
712 if (ret < 0)
713 goto unlock;
714 }
715
716 ret = __generic_file_write_iter(iocb, iter);
717 if (ret < 0)
718 goto unlock;
719
720 inode_unlock(inode);
721
722 if (pos > valid_size)
723 pos = valid_size;
724
725 if (iocb->ki_pos > pos) {
726 ssize_t err = generic_write_sync(iocb, iocb->ki_pos - pos);
727
728 if (err < 0)
729 return err;
730 }
731
732 return ret;
733
734 unlock:
735 inode_unlock(inode);
736
737 return ret;
738 }
739
exfat_file_read_iter(struct kiocb * iocb,struct iov_iter * iter)740 static ssize_t exfat_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
741 {
742 struct inode *inode = file_inode(iocb->ki_filp);
743
744 if (unlikely(exfat_forced_shutdown(inode->i_sb)))
745 return -EIO;
746
747 return generic_file_read_iter(iocb, iter);
748 }
749
exfat_page_mkwrite(struct vm_fault * vmf)750 static vm_fault_t exfat_page_mkwrite(struct vm_fault *vmf)
751 {
752 int err;
753 struct inode *inode = file_inode(vmf->vma->vm_file);
754 struct exfat_inode_info *ei = EXFAT_I(inode);
755 loff_t new_valid_size;
756
757 if (!inode_trylock(inode))
758 return VM_FAULT_RETRY;
759
760 new_valid_size = ((loff_t)vmf->pgoff + 1) << PAGE_SHIFT;
761 new_valid_size = min(new_valid_size, i_size_read(inode));
762
763 if (ei->valid_size < new_valid_size) {
764 err = exfat_extend_valid_size(inode, new_valid_size);
765 if (err < 0) {
766 inode_unlock(inode);
767 return vmf_fs_error(err);
768 }
769 }
770
771 inode_unlock(inode);
772
773 return filemap_page_mkwrite(vmf);
774 }
775
776 static const struct vm_operations_struct exfat_file_vm_ops = {
777 .fault = filemap_fault,
778 .map_pages = filemap_map_pages,
779 .page_mkwrite = exfat_page_mkwrite,
780 };
781
exfat_file_mmap_prepare(struct vm_area_desc * desc)782 static int exfat_file_mmap_prepare(struct vm_area_desc *desc)
783 {
784 struct file *file = desc->file;
785
786 if (unlikely(exfat_forced_shutdown(file_inode(desc->file)->i_sb)))
787 return -EIO;
788
789 file_accessed(file);
790 desc->vm_ops = &exfat_file_vm_ops;
791 return 0;
792 }
793
exfat_splice_read(struct file * in,loff_t * ppos,struct pipe_inode_info * pipe,size_t len,unsigned int flags)794 static ssize_t exfat_splice_read(struct file *in, loff_t *ppos,
795 struct pipe_inode_info *pipe, size_t len, unsigned int flags)
796 {
797 if (unlikely(exfat_forced_shutdown(file_inode(in)->i_sb)))
798 return -EIO;
799
800 return filemap_splice_read(in, ppos, pipe, len, flags);
801 }
802
803 const struct file_operations exfat_file_operations = {
804 .llseek = generic_file_llseek,
805 .read_iter = exfat_file_read_iter,
806 .write_iter = exfat_file_write_iter,
807 .unlocked_ioctl = exfat_ioctl,
808 #ifdef CONFIG_COMPAT
809 .compat_ioctl = exfat_compat_ioctl,
810 #endif
811 .mmap_prepare = exfat_file_mmap_prepare,
812 .fsync = exfat_file_fsync,
813 .splice_read = exfat_splice_read,
814 .splice_write = iter_file_splice_write,
815 .fallocate = exfat_fallocate,
816 .setlease = generic_setlease,
817 };
818
819 const struct inode_operations exfat_file_inode_operations = {
820 .setattr = exfat_setattr,
821 .getattr = exfat_getattr,
822 };
823