1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
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>
16 #include "exfat_raw.h"
19 static int exfat_cont_expand(struct inode *inode, loff_t size)
22 unsigned int num_clusters, new_num_clusters, last_clu;
23 struct exfat_inode_info *ei = EXFAT_I(inode);
24 struct super_block *sb = inode->i_sb;
25 struct exfat_sb_info *sbi = EXFAT_SB(sb);
26 struct exfat_chain clu;
28 ret = inode_newsize_ok(inode, size);
32 num_clusters = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
33 new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi);
35 if (new_num_clusters == num_clusters)
38 exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags);
39 ret = exfat_find_last_cluster(sb, &clu, &last_clu);
43 clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?
44 EXFAT_EOF_CLUSTER : last_clu + 1;
46 clu.flags = ei->flags;
48 ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters,
49 &clu, IS_DIRSYNC(inode));
53 /* Append new clusters to chain */
54 if (clu.flags != ei->flags) {
55 exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters);
56 ei->flags = ALLOC_FAT_CHAIN;
58 if (clu.flags == ALLOC_FAT_CHAIN)
59 if (exfat_ent_set(sb, last_clu, clu.dir))
62 if (num_clusters == 0)
63 ei->start_clu = clu.dir;
66 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
67 /* Expanded range not zeroed, do not update valid_size */
68 i_size_write(inode, size);
70 ei->i_size_aligned = round_up(size, sb->s_blocksize);
71 ei->i_size_ondisk = ei->i_size_aligned;
72 inode->i_blocks = round_up(size, sbi->cluster_size) >> 9;
74 if (IS_DIRSYNC(inode))
75 return write_inode_now(inode, 1);
77 mark_inode_dirty(inode);
82 exfat_free_cluster(inode, &clu);
86 static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)
88 mode_t allow_utime = sbi->options.allow_utime;
90 if (!uid_eq(current_fsuid(), inode->i_uid)) {
91 if (in_group_p(inode->i_gid))
93 if (allow_utime & MAY_WRITE)
97 /* use a default check */
101 static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
102 struct inode *inode, umode_t *mode_ptr)
104 mode_t i_mode, mask, perm;
106 i_mode = inode->i_mode;
108 mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?
109 sbi->options.fs_fmask : sbi->options.fs_dmask;
110 perm = *mode_ptr & ~(S_IFMT | mask);
112 /* Of the r and x bits, all (subject to umask) must be present.*/
113 if ((perm & 0555) != (i_mode & 0555))
116 if (exfat_mode_can_hold_ro(inode)) {
118 * Of the w bits, either all (subject to umask) or none must
121 if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
125 * If exfat_mode_can_hold_ro(inode) is false, can't change
128 if ((perm & 0222) != (0222 & ~mask))
132 *mode_ptr &= S_IFMT | perm;
137 /* resize the file length */
138 int __exfat_truncate(struct inode *inode)
140 unsigned int num_clusters_new, num_clusters_phys;
141 unsigned int last_clu = EXFAT_FREE_CLUSTER;
142 struct exfat_chain clu;
143 struct super_block *sb = inode->i_sb;
144 struct exfat_sb_info *sbi = EXFAT_SB(sb);
145 struct exfat_inode_info *ei = EXFAT_I(inode);
147 /* check if the given file ID is opened */
148 if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
151 exfat_set_volume_dirty(sb);
153 num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
154 num_clusters_phys = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
156 exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
158 if (i_size_read(inode) > 0) {
160 * Truncate FAT chain num_clusters after the first cluster
161 * num_clusters = min(new, phys);
163 unsigned int num_clusters =
164 min(num_clusters_new, num_clusters_phys);
168 * (defensive coding - works fine even with corrupted FAT table
170 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
171 clu.dir += num_clusters;
172 clu.size -= num_clusters;
174 while (num_clusters > 0) {
176 if (exfat_get_next_cluster(sb, &(clu.dir)))
184 ei->flags = ALLOC_NO_FAT_CHAIN;
185 ei->start_clu = EXFAT_EOF_CLUSTER;
188 if (i_size_read(inode) < ei->valid_size)
189 ei->valid_size = i_size_read(inode);
191 if (ei->type == TYPE_FILE)
192 ei->attr |= EXFAT_ATTR_ARCHIVE;
195 * update the directory entry
197 * If the directory entry is updated by mark_inode_dirty(), the
198 * directory entry will be written after a writeback cycle of
199 * updating the bitmap/FAT, which may result in clusters being
200 * freed but referenced by the directory entry in the event of a
201 * sudden power failure.
202 * __exfat_write_inode() is called for directory entry, bitmap
203 * and FAT to be written in a same writeback.
205 if (__exfat_write_inode(inode, inode_needs_sync(inode)))
208 /* cut off from the FAT chain */
209 if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
210 last_clu != EXFAT_EOF_CLUSTER) {
211 if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
215 /* invalidate cache and free the clusters */
216 /* clear exfat cache */
217 exfat_cache_inval_inode(inode);
219 /* hint information */
220 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
221 ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
223 /* hint_stat will be used if this is directory. */
224 ei->hint_stat.eidx = 0;
225 ei->hint_stat.clu = ei->start_clu;
226 ei->hint_femp.eidx = EXFAT_HINT_NONE;
228 /* free the clusters */
229 if (exfat_free_cluster(inode, &clu))
235 void exfat_truncate(struct inode *inode)
237 struct super_block *sb = inode->i_sb;
238 struct exfat_sb_info *sbi = EXFAT_SB(sb);
239 struct exfat_inode_info *ei = EXFAT_I(inode);
240 unsigned int blocksize = i_blocksize(inode);
244 mutex_lock(&sbi->s_lock);
245 if (ei->start_clu == 0) {
247 * Empty start_clu != ~0 (not allocated)
249 exfat_fs_error(sb, "tried to truncate zeroed cluster.");
253 err = __exfat_truncate(inode);
257 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
259 aligned_size = i_size_read(inode);
260 if (aligned_size & (blocksize - 1)) {
261 aligned_size |= (blocksize - 1);
265 if (ei->i_size_ondisk > i_size_read(inode))
266 ei->i_size_ondisk = aligned_size;
268 if (ei->i_size_aligned > i_size_read(inode))
269 ei->i_size_aligned = aligned_size;
270 mutex_unlock(&sbi->s_lock);
273 int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
274 struct kstat *stat, unsigned int request_mask,
275 unsigned int query_flags)
277 struct inode *inode = d_backing_inode(path->dentry);
278 struct exfat_inode_info *ei = EXFAT_I(inode);
280 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
281 exfat_truncate_atime(&stat->atime);
282 stat->result_mask |= STATX_BTIME;
283 stat->btime.tv_sec = ei->i_crtime.tv_sec;
284 stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
285 stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
289 int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
292 struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
293 struct inode *inode = dentry->d_inode;
294 unsigned int ia_valid;
297 if ((attr->ia_valid & ATTR_SIZE) &&
298 attr->ia_size > i_size_read(inode)) {
299 error = exfat_cont_expand(inode, attr->ia_size);
300 if (error || attr->ia_valid == ATTR_SIZE)
302 attr->ia_valid &= ~ATTR_SIZE;
305 /* Check for setting the inode time. */
306 ia_valid = attr->ia_valid;
307 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
308 exfat_allow_set_time(sbi, inode)) {
309 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
313 error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
314 attr->ia_valid = ia_valid;
318 if (((attr->ia_valid & ATTR_UID) &&
319 !uid_eq(attr->ia_uid, sbi->options.fs_uid)) ||
320 ((attr->ia_valid & ATTR_GID) &&
321 !gid_eq(attr->ia_gid, sbi->options.fs_gid)) ||
322 ((attr->ia_valid & ATTR_MODE) &&
323 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
329 * We don't return -EPERM here. Yes, strange, but this is too
332 if (attr->ia_valid & ATTR_MODE) {
333 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
334 attr->ia_valid &= ~ATTR_MODE;
337 if (attr->ia_valid & ATTR_SIZE)
338 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
340 setattr_copy(&nop_mnt_idmap, inode, attr);
341 exfat_truncate_inode_atime(inode);
343 if (attr->ia_valid & ATTR_SIZE) {
344 error = exfat_block_truncate_page(inode, attr->ia_size);
348 down_write(&EXFAT_I(inode)->truncate_lock);
349 truncate_setsize(inode, attr->ia_size);
352 * __exfat_write_inode() is called from exfat_truncate(), inode
353 * is already written by it, so mark_inode_dirty() is unneeded.
355 exfat_truncate(inode);
356 up_write(&EXFAT_I(inode)->truncate_lock);
358 mark_inode_dirty(inode);
365 * modified ioctls from fat/file.c by Welmer Almesberger
367 static int exfat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
371 inode_lock_shared(inode);
372 attr = exfat_make_attr(inode);
373 inode_unlock_shared(inode);
375 return put_user(attr, user_attr);
378 static int exfat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
380 struct inode *inode = file_inode(file);
381 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
382 int is_dir = S_ISDIR(inode->i_mode);
387 err = get_user(attr, user_attr);
391 err = mnt_want_write_file(file);
396 oldattr = exfat_make_attr(inode);
399 * Mask attributes so we don't set reserved fields.
401 attr &= (EXFAT_ATTR_READONLY | EXFAT_ATTR_HIDDEN | EXFAT_ATTR_SYSTEM |
403 attr |= (is_dir ? EXFAT_ATTR_SUBDIR : 0);
405 /* Equivalent to a chmod() */
406 ia.ia_valid = ATTR_MODE | ATTR_CTIME;
407 ia.ia_ctime = current_time(inode);
409 ia.ia_mode = exfat_make_mode(sbi, attr, 0777);
411 ia.ia_mode = exfat_make_mode(sbi, attr, 0666 | (inode->i_mode & 0111));
413 /* The root directory has no attributes */
414 if (inode->i_ino == EXFAT_ROOT_INO && attr != EXFAT_ATTR_SUBDIR) {
416 goto out_unlock_inode;
419 if (((attr | oldattr) & EXFAT_ATTR_SYSTEM) &&
420 !capable(CAP_LINUX_IMMUTABLE)) {
422 goto out_unlock_inode;
426 * The security check is questionable... We single
427 * out the RO attribute for checking by the security
428 * module, just because it maps to a file mode.
430 err = security_inode_setattr(file_mnt_idmap(file),
431 file->f_path.dentry, &ia);
433 goto out_unlock_inode;
435 /* This MUST be done before doing anything irreversible... */
436 err = exfat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);
438 goto out_unlock_inode;
440 fsnotify_change(file->f_path.dentry, ia.ia_valid);
442 exfat_save_attr(inode, attr);
443 mark_inode_dirty(inode);
446 mnt_drop_write_file(file);
451 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
453 struct fstrim_range range;
456 if (!capable(CAP_SYS_ADMIN))
459 if (!bdev_max_discard_sectors(inode->i_sb->s_bdev))
462 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))
465 range.minlen = max_t(unsigned int, range.minlen,
466 bdev_discard_granularity(inode->i_sb->s_bdev));
468 ret = exfat_trim_fs(inode, &range);
472 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))
478 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
480 struct inode *inode = file_inode(filp);
481 u32 __user *user_attr = (u32 __user *)arg;
484 case FAT_IOCTL_GET_ATTRIBUTES:
485 return exfat_ioctl_get_attributes(inode, user_attr);
486 case FAT_IOCTL_SET_ATTRIBUTES:
487 return exfat_ioctl_set_attributes(filp, user_attr);
489 return exfat_ioctl_fitrim(inode, arg);
496 long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
499 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
503 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
505 struct inode *inode = filp->f_mapping->host;
508 err = __generic_file_fsync(filp, start, end, datasync);
512 err = sync_blockdev(inode->i_sb->s_bdev);
516 return blkdev_issue_flush(inode->i_sb->s_bdev);
519 static int exfat_file_zeroed_range(struct file *file, loff_t start, loff_t end)
522 struct inode *inode = file_inode(file);
523 struct address_space *mapping = inode->i_mapping;
524 const struct address_space_operations *ops = mapping->a_ops;
526 while (start < end) {
528 struct page *page = NULL;
530 zerofrom = start & (PAGE_SIZE - 1);
531 len = PAGE_SIZE - zerofrom;
532 if (start + len > end)
535 err = ops->write_begin(file, mapping, start, len, &page, NULL);
539 zero_user_segment(page, zerofrom, zerofrom + len);
541 err = ops->write_end(file, mapping, start, len, len, page, NULL);
546 balance_dirty_pages_ratelimited(mapping);
554 static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
557 struct file *file = iocb->ki_filp;
558 struct inode *inode = file_inode(file);
559 struct exfat_inode_info *ei = EXFAT_I(inode);
560 loff_t pos = iocb->ki_pos;
565 valid_size = ei->valid_size;
567 ret = generic_write_checks(iocb, iter);
571 if (pos > valid_size) {
572 ret = exfat_file_zeroed_range(file, valid_size, pos);
573 if (ret < 0 && ret != -ENOSPC) {
574 exfat_err(inode->i_sb,
575 "write: fail to zero from %llu to %llu(%zd)",
576 valid_size, pos, ret);
582 ret = __generic_file_write_iter(iocb, iter);
588 if (pos > valid_size)
591 if (iocb_is_dsync(iocb) && iocb->ki_pos > pos) {
592 ssize_t err = vfs_fsync_range(file, pos, iocb->ki_pos - 1,
593 iocb->ki_flags & IOCB_SYNC);
606 static int exfat_file_mmap(struct file *file, struct vm_area_struct *vma)
609 struct inode *inode = file_inode(file);
610 struct exfat_inode_info *ei = EXFAT_I(inode);
611 loff_t start = ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
612 loff_t end = min_t(loff_t, i_size_read(inode),
613 start + vma->vm_end - vma->vm_start);
615 if ((vma->vm_flags & VM_WRITE) && ei->valid_size < end) {
616 ret = exfat_file_zeroed_range(file, ei->valid_size, end);
618 exfat_err(inode->i_sb,
619 "mmap: fail to zero from %llu to %llu(%d)",
625 return generic_file_mmap(file, vma);
628 const struct file_operations exfat_file_operations = {
629 .llseek = generic_file_llseek,
630 .read_iter = generic_file_read_iter,
631 .write_iter = exfat_file_write_iter,
632 .unlocked_ioctl = exfat_ioctl,
634 .compat_ioctl = exfat_compat_ioctl,
636 .mmap = exfat_file_mmap,
637 .fsync = exfat_file_fsync,
638 .splice_read = filemap_splice_read,
639 .splice_write = iter_file_splice_write,
642 const struct inode_operations exfat_file_inode_operations = {
643 .setattr = exfat_setattr,
644 .getattr = exfat_getattr,