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
exfat_cont_expand(struct inode * inode,loff_t size)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
exfat_allow_set_time(struct exfat_sb_info * sbi,struct inode * inode)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
exfat_sanitize_mode(const struct exfat_sb_info * sbi,struct inode * inode,umode_t * mode_ptr)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 */
__exfat_truncate(struct inode * inode,loff_t new_size)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
exfat_truncate(struct inode * inode,loff_t size)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) >> 9;
255 write_size:
256 aligned_size = i_size_read(inode);
257 if (aligned_size & (blocksize - 1)) {
258 aligned_size |= (blocksize - 1);
259 aligned_size++;
260 }
261
262 if (ei->i_size_ondisk > i_size_read(inode))
263 ei->i_size_ondisk = aligned_size;
264
265 if (ei->i_size_aligned > i_size_read(inode))
266 ei->i_size_aligned = aligned_size;
267 mutex_unlock(&sbi->s_lock);
268 }
269
exfat_getattr(struct user_namespace * mnt_uerns,const struct path * path,struct kstat * stat,unsigned int request_mask,unsigned int query_flags)270 int exfat_getattr(struct user_namespace *mnt_uerns, const struct path *path,
271 struct kstat *stat, unsigned int request_mask,
272 unsigned int query_flags)
273 {
274 struct inode *inode = d_backing_inode(path->dentry);
275 struct exfat_inode_info *ei = EXFAT_I(inode);
276
277 generic_fillattr(&init_user_ns, inode, stat);
278 exfat_truncate_atime(&stat->atime);
279 stat->result_mask |= STATX_BTIME;
280 stat->btime.tv_sec = ei->i_crtime.tv_sec;
281 stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
282 stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
283 return 0;
284 }
285
exfat_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)286 int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
287 struct iattr *attr)
288 {
289 struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
290 struct inode *inode = dentry->d_inode;
291 unsigned int ia_valid;
292 int error;
293
294 if ((attr->ia_valid & ATTR_SIZE) &&
295 attr->ia_size > i_size_read(inode)) {
296 error = exfat_cont_expand(inode, attr->ia_size);
297 if (error || attr->ia_valid == ATTR_SIZE)
298 return error;
299 attr->ia_valid &= ~ATTR_SIZE;
300 }
301
302 /* Check for setting the inode time. */
303 ia_valid = attr->ia_valid;
304 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
305 exfat_allow_set_time(sbi, inode)) {
306 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
307 ATTR_TIMES_SET);
308 }
309
310 error = setattr_prepare(&init_user_ns, dentry, attr);
311 attr->ia_valid = ia_valid;
312 if (error)
313 goto out;
314
315 if (((attr->ia_valid & ATTR_UID) &&
316 !uid_eq(attr->ia_uid, sbi->options.fs_uid)) ||
317 ((attr->ia_valid & ATTR_GID) &&
318 !gid_eq(attr->ia_gid, sbi->options.fs_gid)) ||
319 ((attr->ia_valid & ATTR_MODE) &&
320 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
321 error = -EPERM;
322 goto out;
323 }
324
325 /*
326 * We don't return -EPERM here. Yes, strange, but this is too
327 * old behavior.
328 */
329 if (attr->ia_valid & ATTR_MODE) {
330 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
331 attr->ia_valid &= ~ATTR_MODE;
332 }
333
334 if (attr->ia_valid & ATTR_SIZE) {
335 error = exfat_block_truncate_page(inode, attr->ia_size);
336 if (error)
337 goto out;
338
339 down_write(&EXFAT_I(inode)->truncate_lock);
340 truncate_setsize(inode, attr->ia_size);
341 exfat_truncate(inode, attr->ia_size);
342 up_write(&EXFAT_I(inode)->truncate_lock);
343 }
344
345 setattr_copy(&init_user_ns, inode, attr);
346 exfat_truncate_atime(&inode->i_atime);
347 mark_inode_dirty(inode);
348
349 out:
350 return error;
351 }
352
exfat_ioctl_fitrim(struct inode * inode,unsigned long arg)353 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
354 {
355 struct request_queue *q = bdev_get_queue(inode->i_sb->s_bdev);
356 struct fstrim_range range;
357 int ret = 0;
358
359 if (!capable(CAP_SYS_ADMIN))
360 return -EPERM;
361
362 if (!blk_queue_discard(q))
363 return -EOPNOTSUPP;
364
365 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))
366 return -EFAULT;
367
368 range.minlen = max_t(unsigned int, range.minlen,
369 q->limits.discard_granularity);
370
371 ret = exfat_trim_fs(inode, &range);
372 if (ret < 0)
373 return ret;
374
375 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))
376 return -EFAULT;
377
378 return 0;
379 }
380
exfat_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)381 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
382 {
383 struct inode *inode = file_inode(filp);
384
385 switch (cmd) {
386 case FITRIM:
387 return exfat_ioctl_fitrim(inode, arg);
388 default:
389 return -ENOTTY;
390 }
391 }
392
393 #ifdef CONFIG_COMPAT
exfat_compat_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)394 long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
395 unsigned long arg)
396 {
397 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
398 }
399 #endif
400
exfat_file_fsync(struct file * filp,loff_t start,loff_t end,int datasync)401 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
402 {
403 struct inode *inode = filp->f_mapping->host;
404 int err;
405
406 err = __generic_file_fsync(filp, start, end, datasync);
407 if (err)
408 return err;
409
410 err = sync_blockdev(inode->i_sb->s_bdev);
411 if (err)
412 return err;
413
414 return blkdev_issue_flush(inode->i_sb->s_bdev);
415 }
416
417 const struct file_operations exfat_file_operations = {
418 .llseek = generic_file_llseek,
419 .read_iter = generic_file_read_iter,
420 .write_iter = generic_file_write_iter,
421 .unlocked_ioctl = exfat_ioctl,
422 #ifdef CONFIG_COMPAT
423 .compat_ioctl = exfat_compat_ioctl,
424 #endif
425 .mmap = generic_file_mmap,
426 .fsync = exfat_file_fsync,
427 .splice_read = generic_file_splice_read,
428 .splice_write = iter_file_splice_write,
429 };
430
431 const struct inode_operations exfat_file_inode_operations = {
432 .setattr = exfat_setattr,
433 .getattr = exfat_getattr,
434 };
435