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 =
114 EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk, sbi);
115
116 exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
117
118 if (new_size > 0) {
119 /*
120 * Truncate FAT chain num_clusters after the first cluster
121 * num_clusters = min(new, phys);
122 */
123 unsigned int num_clusters =
124 min(num_clusters_new, num_clusters_phys);
125
126 /*
127 * Follow FAT chain
128 * (defensive coding - works fine even with corrupted FAT table
129 */
130 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
131 clu.dir += num_clusters;
132 clu.size -= num_clusters;
133 } else {
134 while (num_clusters > 0) {
135 last_clu = clu.dir;
136 if (exfat_get_next_cluster(sb, &(clu.dir)))
137 return -EIO;
138
139 num_clusters--;
140 clu.size--;
141 }
142 }
143 } else {
144 ei->flags = ALLOC_NO_FAT_CHAIN;
145 ei->start_clu = EXFAT_EOF_CLUSTER;
146 }
147
148 i_size_write(inode, new_size);
149
150 if (ei->type == TYPE_FILE)
151 ei->attr |= ATTR_ARCHIVE;
152
153 /* update the directory entry */
154 if (!evict) {
155 struct timespec64 ts;
156 struct exfat_dentry *ep, *ep2;
157 struct exfat_entry_set_cache *es;
158 int err;
159
160 es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
161 ES_ALL_ENTRIES);
162 if (!es)
163 return -EIO;
164 ep = exfat_get_dentry_cached(es, 0);
165 ep2 = exfat_get_dentry_cached(es, 1);
166
167 ts = current_time(inode);
168 exfat_set_entry_time(sbi, &ts,
169 &ep->dentry.file.modify_tz,
170 &ep->dentry.file.modify_time,
171 &ep->dentry.file.modify_date,
172 &ep->dentry.file.modify_time_cs);
173 ep->dentry.file.attr = cpu_to_le16(ei->attr);
174
175 /* File size should be zero if there is no cluster allocated */
176 if (ei->start_clu == EXFAT_EOF_CLUSTER) {
177 ep2->dentry.stream.valid_size = 0;
178 ep2->dentry.stream.size = 0;
179 } else {
180 ep2->dentry.stream.valid_size = cpu_to_le64(new_size);
181 ep2->dentry.stream.size = ep2->dentry.stream.valid_size;
182 }
183
184 if (new_size == 0) {
185 /* Any directory can not be truncated to zero */
186 WARN_ON(ei->type != TYPE_FILE);
187
188 ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;
189 ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
190 }
191
192 exfat_update_dir_chksum_with_entry_set(es);
193 err = exfat_free_dentry_set(es, inode_needs_sync(inode));
194 if (err)
195 return err;
196 }
197
198 /* cut off from the FAT chain */
199 if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
200 last_clu != EXFAT_EOF_CLUSTER) {
201 if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
202 return -EIO;
203 }
204
205 /* invalidate cache and free the clusters */
206 /* clear exfat cache */
207 exfat_cache_inval_inode(inode);
208
209 /* hint information */
210 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
211 ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
212
213 /* hint_stat will be used if this is directory. */
214 ei->hint_stat.eidx = 0;
215 ei->hint_stat.clu = ei->start_clu;
216 ei->hint_femp.eidx = EXFAT_HINT_NONE;
217
218 /* free the clusters */
219 if (exfat_free_cluster(inode, &clu))
220 return -EIO;
221
222 exfat_clear_volume_dirty(sb);
223
224 return 0;
225 }
226
exfat_truncate(struct inode * inode,loff_t size)227 void exfat_truncate(struct inode *inode, loff_t size)
228 {
229 struct super_block *sb = inode->i_sb;
230 struct exfat_sb_info *sbi = EXFAT_SB(sb);
231 unsigned int blocksize = i_blocksize(inode);
232 loff_t aligned_size;
233 int err;
234
235 mutex_lock(&sbi->s_lock);
236 if (EXFAT_I(inode)->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 = ((i_size_read(inode) + (sbi->cluster_size - 1)) &
255 ~(sbi->cluster_size - 1)) >> 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 (EXFAT_I(inode)->i_size_ondisk > i_size_read(inode))
264 EXFAT_I(inode)->i_size_ondisk = aligned_size;
265
266 if (EXFAT_I(inode)->i_size_aligned > i_size_read(inode))
267 EXFAT_I(inode)->i_size_aligned = aligned_size;
268 mutex_unlock(&sbi->s_lock);
269 }
270
exfat_getattr(struct user_namespace * mnt_uerns,const struct path * path,struct kstat * stat,unsigned int request_mask,unsigned int query_flags)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
exfat_setattr(struct user_namespace * mnt_userns,struct dentry * dentry,struct iattr * attr)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
exfat_ioctl_fitrim(struct inode * inode,unsigned long arg)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
exfat_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)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
exfat_compat_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)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
exfat_file_fsync(struct file * filp,loff_t start,loff_t end,int datasync)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
