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)
39 exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags);
40 ret = exfat_find_last_cluster(sb, &clu, &last_clu);
44 clu.dir = last_clu + 1;
46 last_clu = EXFAT_EOF_CLUSTER;
47 clu.dir = EXFAT_EOF_CLUSTER;
51 clu.flags = ei->flags;
53 ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters,
54 &clu, IS_DIRSYNC(inode));
58 /* Append new clusters to chain */
60 if (clu.flags != ei->flags)
61 if (exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters))
64 if (clu.flags == ALLOC_FAT_CHAIN)
65 if (exfat_ent_set(sb, last_clu, clu.dir))
68 ei->start_clu = clu.dir;
70 ei->flags = clu.flags;
73 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
74 /* Expanded range not zeroed, do not update valid_size */
75 i_size_write(inode, size);
77 ei->i_size_aligned = round_up(size, sb->s_blocksize);
78 ei->i_size_ondisk = ei->i_size_aligned;
79 inode->i_blocks = round_up(size, sbi->cluster_size) >> 9;
81 if (IS_DIRSYNC(inode))
82 return write_inode_now(inode, 1);
84 mark_inode_dirty(inode);
89 exfat_free_cluster(inode, &clu);
93 static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)
95 mode_t allow_utime = sbi->options.allow_utime;
97 if (!uid_eq(current_fsuid(), inode->i_uid)) {
98 if (in_group_p(inode->i_gid))
100 if (allow_utime & MAY_WRITE)
104 /* use a default check */
108 static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
109 struct inode *inode, umode_t *mode_ptr)
111 mode_t i_mode, mask, perm;
113 i_mode = inode->i_mode;
115 mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?
116 sbi->options.fs_fmask : sbi->options.fs_dmask;
117 perm = *mode_ptr & ~(S_IFMT | mask);
119 /* Of the r and x bits, all (subject to umask) must be present.*/
120 if ((perm & 0555) != (i_mode & 0555))
123 if (exfat_mode_can_hold_ro(inode)) {
125 * Of the w bits, either all (subject to umask) or none must
128 if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
132 * If exfat_mode_can_hold_ro(inode) is false, can't change
135 if ((perm & 0222) != (0222 & ~mask))
139 *mode_ptr &= S_IFMT | perm;
144 /* resize the file length */
145 int __exfat_truncate(struct inode *inode)
147 unsigned int num_clusters_new, num_clusters_phys;
148 unsigned int last_clu = EXFAT_FREE_CLUSTER;
149 struct exfat_chain clu;
150 struct super_block *sb = inode->i_sb;
151 struct exfat_sb_info *sbi = EXFAT_SB(sb);
152 struct exfat_inode_info *ei = EXFAT_I(inode);
154 /* check if the given file ID is opened */
155 if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
158 exfat_set_volume_dirty(sb);
160 num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
161 num_clusters_phys = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
163 exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
165 if (i_size_read(inode) > 0) {
167 * Truncate FAT chain num_clusters after the first cluster
168 * num_clusters = min(new, phys);
170 unsigned int num_clusters =
171 min(num_clusters_new, num_clusters_phys);
175 * (defensive coding - works fine even with corrupted FAT table
177 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
178 clu.dir += num_clusters;
179 clu.size -= num_clusters;
181 while (num_clusters > 0) {
183 if (exfat_get_next_cluster(sb, &(clu.dir)))
191 ei->flags = ALLOC_NO_FAT_CHAIN;
192 ei->start_clu = EXFAT_EOF_CLUSTER;
195 if (i_size_read(inode) < ei->valid_size)
196 ei->valid_size = i_size_read(inode);
198 if (ei->type == TYPE_FILE)
199 ei->attr |= EXFAT_ATTR_ARCHIVE;
202 * update the directory entry
204 * If the directory entry is updated by mark_inode_dirty(), the
205 * directory entry will be written after a writeback cycle of
206 * updating the bitmap/FAT, which may result in clusters being
207 * freed but referenced by the directory entry in the event of a
208 * sudden power failure.
209 * __exfat_write_inode() is called for directory entry, bitmap
210 * and FAT to be written in a same writeback.
212 if (__exfat_write_inode(inode, inode_needs_sync(inode)))
215 /* cut off from the FAT chain */
216 if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
217 last_clu != EXFAT_EOF_CLUSTER) {
218 if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
222 /* invalidate cache and free the clusters */
223 /* clear exfat cache */
224 exfat_cache_inval_inode(inode);
226 /* hint information */
227 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
228 ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
230 /* hint_stat will be used if this is directory. */
231 ei->hint_stat.eidx = 0;
232 ei->hint_stat.clu = ei->start_clu;
233 ei->hint_femp.eidx = EXFAT_HINT_NONE;
235 /* free the clusters */
236 if (exfat_free_cluster(inode, &clu))
242 void exfat_truncate(struct inode *inode)
244 struct super_block *sb = inode->i_sb;
245 struct exfat_sb_info *sbi = EXFAT_SB(sb);
246 struct exfat_inode_info *ei = EXFAT_I(inode);
247 unsigned int blocksize = i_blocksize(inode);
251 mutex_lock(&sbi->s_lock);
252 if (ei->start_clu == 0) {
254 * Empty start_clu != ~0 (not allocated)
256 exfat_fs_error(sb, "tried to truncate zeroed cluster.");
260 err = __exfat_truncate(inode);
264 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
266 aligned_size = i_size_read(inode);
267 if (aligned_size & (blocksize - 1)) {
268 aligned_size |= (blocksize - 1);
272 if (ei->i_size_ondisk > i_size_read(inode))
273 ei->i_size_ondisk = aligned_size;
275 if (ei->i_size_aligned > i_size_read(inode))
276 ei->i_size_aligned = aligned_size;
277 mutex_unlock(&sbi->s_lock);
280 int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
281 struct kstat *stat, unsigned int request_mask,
282 unsigned int query_flags)
284 struct inode *inode = d_backing_inode(path->dentry);
285 struct exfat_inode_info *ei = EXFAT_I(inode);
287 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
288 exfat_truncate_atime(&stat->atime);
289 stat->result_mask |= STATX_BTIME;
290 stat->btime.tv_sec = ei->i_crtime.tv_sec;
291 stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
292 stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
296 int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
299 struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
300 struct inode *inode = dentry->d_inode;
301 unsigned int ia_valid;
304 if ((attr->ia_valid & ATTR_SIZE) &&
305 attr->ia_size > i_size_read(inode)) {
306 error = exfat_cont_expand(inode, attr->ia_size);
307 if (error || attr->ia_valid == ATTR_SIZE)
309 attr->ia_valid &= ~ATTR_SIZE;
312 /* Check for setting the inode time. */
313 ia_valid = attr->ia_valid;
314 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
315 exfat_allow_set_time(sbi, inode)) {
316 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
320 error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
321 attr->ia_valid = ia_valid;
325 if (((attr->ia_valid & ATTR_UID) &&
326 !uid_eq(attr->ia_uid, sbi->options.fs_uid)) ||
327 ((attr->ia_valid & ATTR_GID) &&
328 !gid_eq(attr->ia_gid, sbi->options.fs_gid)) ||
329 ((attr->ia_valid & ATTR_MODE) &&
330 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
336 * We don't return -EPERM here. Yes, strange, but this is too
339 if (attr->ia_valid & ATTR_MODE) {
340 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
341 attr->ia_valid &= ~ATTR_MODE;
344 if (attr->ia_valid & ATTR_SIZE)
345 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
347 setattr_copy(&nop_mnt_idmap, inode, attr);
348 exfat_truncate_inode_atime(inode);
350 if (attr->ia_valid & ATTR_SIZE) {
351 error = exfat_block_truncate_page(inode, attr->ia_size);
355 down_write(&EXFAT_I(inode)->truncate_lock);
356 truncate_setsize(inode, attr->ia_size);
359 * __exfat_write_inode() is called from exfat_truncate(), inode
360 * is already written by it, so mark_inode_dirty() is unneeded.
362 exfat_truncate(inode);
363 up_write(&EXFAT_I(inode)->truncate_lock);
365 mark_inode_dirty(inode);
372 * modified ioctls from fat/file.c by Welmer Almesberger
374 static int exfat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
378 inode_lock_shared(inode);
379 attr = exfat_make_attr(inode);
380 inode_unlock_shared(inode);
382 return put_user(attr, user_attr);
385 static int exfat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
387 struct inode *inode = file_inode(file);
388 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
389 int is_dir = S_ISDIR(inode->i_mode);
394 err = get_user(attr, user_attr);
398 err = mnt_want_write_file(file);
403 oldattr = exfat_make_attr(inode);
406 * Mask attributes so we don't set reserved fields.
408 attr &= (EXFAT_ATTR_READONLY | EXFAT_ATTR_HIDDEN | EXFAT_ATTR_SYSTEM |
410 attr |= (is_dir ? EXFAT_ATTR_SUBDIR : 0);
412 /* Equivalent to a chmod() */
413 ia.ia_valid = ATTR_MODE | ATTR_CTIME;
414 ia.ia_ctime = current_time(inode);
416 ia.ia_mode = exfat_make_mode(sbi, attr, 0777);
418 ia.ia_mode = exfat_make_mode(sbi, attr, 0666 | (inode->i_mode & 0111));
420 /* The root directory has no attributes */
421 if (inode->i_ino == EXFAT_ROOT_INO && attr != EXFAT_ATTR_SUBDIR) {
423 goto out_unlock_inode;
426 if (((attr | oldattr) & EXFAT_ATTR_SYSTEM) &&
427 !capable(CAP_LINUX_IMMUTABLE)) {
429 goto out_unlock_inode;
433 * The security check is questionable... We single
434 * out the RO attribute for checking by the security
435 * module, just because it maps to a file mode.
437 err = security_inode_setattr(file_mnt_idmap(file),
438 file->f_path.dentry, &ia);
440 goto out_unlock_inode;
442 /* This MUST be done before doing anything irreversible... */
443 err = exfat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);
445 goto out_unlock_inode;
447 fsnotify_change(file->f_path.dentry, ia.ia_valid);
449 exfat_save_attr(inode, attr);
450 mark_inode_dirty(inode);
453 mnt_drop_write_file(file);
458 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
460 struct fstrim_range range;
463 if (!capable(CAP_SYS_ADMIN))
466 if (!bdev_max_discard_sectors(inode->i_sb->s_bdev))
469 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))
472 range.minlen = max_t(unsigned int, range.minlen,
473 bdev_discard_granularity(inode->i_sb->s_bdev));
475 ret = exfat_trim_fs(inode, &range);
479 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))
485 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
487 struct inode *inode = file_inode(filp);
488 u32 __user *user_attr = (u32 __user *)arg;
491 case FAT_IOCTL_GET_ATTRIBUTES:
492 return exfat_ioctl_get_attributes(inode, user_attr);
493 case FAT_IOCTL_SET_ATTRIBUTES:
494 return exfat_ioctl_set_attributes(filp, user_attr);
496 return exfat_ioctl_fitrim(inode, arg);
503 long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
506 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
510 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
512 struct inode *inode = filp->f_mapping->host;
515 err = __generic_file_fsync(filp, start, end, datasync);
519 err = sync_blockdev(inode->i_sb->s_bdev);
523 return blkdev_issue_flush(inode->i_sb->s_bdev);
526 static int exfat_file_zeroed_range(struct file *file, loff_t start, loff_t end)
529 struct inode *inode = file_inode(file);
530 struct address_space *mapping = inode->i_mapping;
531 const struct address_space_operations *ops = mapping->a_ops;
533 while (start < end) {
535 struct page *page = NULL;
537 zerofrom = start & (PAGE_SIZE - 1);
538 len = PAGE_SIZE - zerofrom;
539 if (start + len > end)
542 err = ops->write_begin(file, mapping, start, len, &page, NULL);
546 zero_user_segment(page, zerofrom, zerofrom + len);
548 err = ops->write_end(file, mapping, start, len, len, page, NULL);
553 balance_dirty_pages_ratelimited(mapping);
561 static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
564 struct file *file = iocb->ki_filp;
565 struct inode *inode = file_inode(file);
566 struct exfat_inode_info *ei = EXFAT_I(inode);
567 loff_t pos = iocb->ki_pos;
572 valid_size = ei->valid_size;
574 ret = generic_write_checks(iocb, iter);
578 if (pos > valid_size) {
579 ret = exfat_file_zeroed_range(file, valid_size, pos);
580 if (ret < 0 && ret != -ENOSPC) {
581 exfat_err(inode->i_sb,
582 "write: fail to zero from %llu to %llu(%zd)",
583 valid_size, pos, ret);
589 ret = __generic_file_write_iter(iocb, iter);
595 if (pos > valid_size)
598 if (iocb_is_dsync(iocb) && iocb->ki_pos > pos) {
599 ssize_t err = vfs_fsync_range(file, pos, iocb->ki_pos - 1,
600 iocb->ki_flags & IOCB_SYNC);
613 static int exfat_file_mmap(struct file *file, struct vm_area_struct *vma)
616 struct inode *inode = file_inode(file);
617 struct exfat_inode_info *ei = EXFAT_I(inode);
618 loff_t start = ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
619 loff_t end = min_t(loff_t, i_size_read(inode),
620 start + vma->vm_end - vma->vm_start);
622 if ((vma->vm_flags & VM_WRITE) && ei->valid_size < end) {
623 ret = exfat_file_zeroed_range(file, ei->valid_size, end);
625 exfat_err(inode->i_sb,
626 "mmap: fail to zero from %llu to %llu(%d)",
632 return generic_file_mmap(file, vma);
635 const struct file_operations exfat_file_operations = {
636 .llseek = generic_file_llseek,
637 .read_iter = generic_file_read_iter,
638 .write_iter = exfat_file_write_iter,
639 .unlocked_ioctl = exfat_ioctl,
641 .compat_ioctl = exfat_compat_ioctl,
643 .mmap = exfat_file_mmap,
644 .fsync = exfat_file_fsync,
645 .splice_read = filemap_splice_read,
646 .splice_write = iter_file_splice_write,
649 const struct inode_operations exfat_file_inode_operations = {
650 .setattr = exfat_setattr,
651 .getattr = exfat_getattr,