1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
6 #include <linux/fs_context.h>
7 #include <linux/fs_parser.h>
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/time.h>
11 #include <linux/mount.h>
12 #include <linux/cred.h>
13 #include <linux/statfs.h>
14 #include <linux/seq_file.h>
15 #include <linux/blkdev.h>
16 #include <linux/fs_struct.h>
17 #include <linux/iversion.h>
18 #include <linux/nls.h>
19 #include <linux/buffer_head.h>
21 #include "exfat_raw.h"
24 static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
25 static struct kmem_cache *exfat_inode_cachep;
27 static void exfat_free_iocharset(struct exfat_sb_info *sbi)
29 if (sbi->options.iocharset != exfat_default_iocharset)
30 kfree(sbi->options.iocharset);
33 static void exfat_delayed_free(struct rcu_head *p)
35 struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);
37 unload_nls(sbi->nls_io);
38 exfat_free_iocharset(sbi);
39 exfat_free_upcase_table(sbi);
43 static void exfat_put_super(struct super_block *sb)
45 struct exfat_sb_info *sbi = EXFAT_SB(sb);
47 mutex_lock(&sbi->s_lock);
48 if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state))
49 sync_blockdev(sb->s_bdev);
50 exfat_set_vol_flags(sb, VOL_CLEAN);
51 exfat_free_bitmap(sbi);
53 mutex_unlock(&sbi->s_lock);
55 call_rcu(&sbi->rcu, exfat_delayed_free);
58 static int exfat_sync_fs(struct super_block *sb, int wait)
60 struct exfat_sb_info *sbi = EXFAT_SB(sb);
63 /* If there are some dirty buffers in the bdev inode */
64 mutex_lock(&sbi->s_lock);
65 if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state)) {
66 sync_blockdev(sb->s_bdev);
67 if (exfat_set_vol_flags(sb, VOL_CLEAN))
70 mutex_unlock(&sbi->s_lock);
74 static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
76 struct super_block *sb = dentry->d_sb;
77 struct exfat_sb_info *sbi = EXFAT_SB(sb);
78 unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);
80 if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
81 mutex_lock(&sbi->s_lock);
82 if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
83 mutex_unlock(&sbi->s_lock);
86 mutex_unlock(&sbi->s_lock);
89 buf->f_type = sb->s_magic;
90 buf->f_bsize = sbi->cluster_size;
91 buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
92 buf->f_bfree = buf->f_blocks - sbi->used_clusters;
93 buf->f_bavail = buf->f_bfree;
94 buf->f_fsid.val[0] = (unsigned int)id;
95 buf->f_fsid.val[1] = (unsigned int)(id >> 32);
96 /* Unicode utf16 255 characters */
97 buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
101 int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flag)
103 struct exfat_sb_info *sbi = EXFAT_SB(sb);
104 struct pbr64 *bpb = (struct pbr64 *)sbi->pbr_bh->b_data;
107 /* flags are not changed */
108 if (sbi->vol_flag == new_flag)
111 sbi->vol_flag = new_flag;
113 /* skip updating volume dirty flag,
114 * if this volume has been mounted with read-only
119 bpb->bsx.vol_flags = cpu_to_le16(new_flag);
121 if (new_flag == VOL_DIRTY && !buffer_dirty(sbi->pbr_bh))
126 set_buffer_uptodate(sbi->pbr_bh);
127 mark_buffer_dirty(sbi->pbr_bh);
130 sync_dirty_buffer(sbi->pbr_bh);
134 static int exfat_show_options(struct seq_file *m, struct dentry *root)
136 struct super_block *sb = root->d_sb;
137 struct exfat_sb_info *sbi = EXFAT_SB(sb);
138 struct exfat_mount_options *opts = &sbi->options;
140 /* Show partition info */
141 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
142 seq_printf(m, ",uid=%u",
143 from_kuid_munged(&init_user_ns, opts->fs_uid));
144 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
145 seq_printf(m, ",gid=%u",
146 from_kgid_munged(&init_user_ns, opts->fs_gid));
147 seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
148 if (opts->allow_utime)
149 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
151 seq_puts(m, ",iocharset=utf8");
152 else if (sbi->nls_io)
153 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
154 if (opts->errors == EXFAT_ERRORS_CONT)
155 seq_puts(m, ",errors=continue");
156 else if (opts->errors == EXFAT_ERRORS_PANIC)
157 seq_puts(m, ",errors=panic");
159 seq_puts(m, ",errors=remount-ro");
161 seq_puts(m, ",discard");
162 if (opts->time_offset)
163 seq_printf(m, ",time_offset=%d", opts->time_offset);
167 static struct inode *exfat_alloc_inode(struct super_block *sb)
169 struct exfat_inode_info *ei;
171 ei = kmem_cache_alloc(exfat_inode_cachep, GFP_NOFS);
175 init_rwsem(&ei->truncate_lock);
176 return &ei->vfs_inode;
179 static void exfat_free_inode(struct inode *inode)
181 kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
184 static const struct super_operations exfat_sops = {
185 .alloc_inode = exfat_alloc_inode,
186 .free_inode = exfat_free_inode,
187 .write_inode = exfat_write_inode,
188 .evict_inode = exfat_evict_inode,
189 .put_super = exfat_put_super,
190 .sync_fs = exfat_sync_fs,
191 .statfs = exfat_statfs,
192 .show_options = exfat_show_options,
208 static const struct constant_table exfat_param_enums[] = {
209 { "continue", EXFAT_ERRORS_CONT },
210 { "panic", EXFAT_ERRORS_PANIC },
211 { "remount-ro", EXFAT_ERRORS_RO },
215 static const struct fs_parameter_spec exfat_parameters[] = {
216 fsparam_u32("uid", Opt_uid),
217 fsparam_u32("gid", Opt_gid),
218 fsparam_u32oct("umask", Opt_umask),
219 fsparam_u32oct("dmask", Opt_dmask),
220 fsparam_u32oct("fmask", Opt_fmask),
221 fsparam_u32oct("allow_utime", Opt_allow_utime),
222 fsparam_string("iocharset", Opt_charset),
223 fsparam_enum("errors", Opt_errors, exfat_param_enums),
224 fsparam_flag("discard", Opt_discard),
225 fsparam_s32("time_offset", Opt_time_offset),
229 static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
231 struct exfat_sb_info *sbi = fc->s_fs_info;
232 struct exfat_mount_options *opts = &sbi->options;
233 struct fs_parse_result result;
236 opt = fs_parse(fc, exfat_parameters, param, &result);
242 opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
245 opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
248 opts->fs_fmask = result.uint_32;
249 opts->fs_dmask = result.uint_32;
252 opts->fs_dmask = result.uint_32;
255 opts->fs_fmask = result.uint_32;
257 case Opt_allow_utime:
258 opts->allow_utime = result.uint_32 & 0022;
261 exfat_free_iocharset(sbi);
262 opts->iocharset = kstrdup(param->string, GFP_KERNEL);
263 if (!opts->iocharset)
267 opts->errors = result.uint_32;
272 case Opt_time_offset:
274 * Make the limit 24 just in case someone invents something
277 if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
279 opts->time_offset = result.int_32;
288 static void exfat_hash_init(struct super_block *sb)
290 struct exfat_sb_info *sbi = EXFAT_SB(sb);
293 spin_lock_init(&sbi->inode_hash_lock);
294 for (i = 0; i < EXFAT_HASH_SIZE; i++)
295 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
298 static int exfat_read_root(struct inode *inode)
300 struct super_block *sb = inode->i_sb;
301 struct exfat_sb_info *sbi = EXFAT_SB(sb);
302 struct exfat_inode_info *ei = EXFAT_I(inode);
303 struct exfat_chain cdir;
304 int num_subdirs, num_clu = 0;
306 exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
308 ei->start_clu = sbi->root_dir;
309 ei->flags = ALLOC_FAT_CHAIN;
313 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
314 ei->hint_stat.eidx = 0;
315 ei->hint_stat.clu = sbi->root_dir;
316 ei->hint_femp.eidx = EXFAT_HINT_NONE;
318 exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
319 if (exfat_count_num_clusters(sb, &cdir, &num_clu))
321 i_size_write(inode, num_clu << sbi->cluster_size_bits);
323 num_subdirs = exfat_count_dir_entries(sb, &cdir);
326 set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
328 inode->i_uid = sbi->options.fs_uid;
329 inode->i_gid = sbi->options.fs_gid;
330 inode_inc_iversion(inode);
331 inode->i_generation = 0;
332 inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777);
333 inode->i_op = &exfat_dir_inode_operations;
334 inode->i_fop = &exfat_dir_operations;
336 inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1))
337 & ~(sbi->cluster_size - 1)) >> inode->i_blkbits;
338 EXFAT_I(inode)->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
339 EXFAT_I(inode)->i_size_aligned = i_size_read(inode);
340 EXFAT_I(inode)->i_size_ondisk = i_size_read(inode);
342 exfat_save_attr(inode, ATTR_SUBDIR);
343 inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
345 exfat_truncate_atime(&inode->i_atime);
346 exfat_cache_init_inode(inode);
350 static struct pbr *exfat_read_pbr_with_logical_sector(struct super_block *sb)
352 struct exfat_sb_info *sbi = EXFAT_SB(sb);
353 struct pbr *p_pbr = (struct pbr *) (sbi->pbr_bh)->b_data;
354 unsigned short logical_sect = 0;
356 logical_sect = 1 << p_pbr->bsx.f64.sect_size_bits;
358 if (!is_power_of_2(logical_sect) ||
359 logical_sect < 512 || logical_sect > 4096) {
360 exfat_msg(sb, KERN_ERR, "bogus logical sector size %u",
365 if (logical_sect < sb->s_blocksize) {
366 exfat_msg(sb, KERN_ERR,
367 "logical sector size too small for device (logical sector size = %u)",
372 if (logical_sect > sb->s_blocksize) {
376 if (!sb_set_blocksize(sb, logical_sect)) {
377 exfat_msg(sb, KERN_ERR,
378 "unable to set blocksize %u", logical_sect);
381 sbi->pbr_bh = sb_bread(sb, 0);
383 exfat_msg(sb, KERN_ERR,
384 "unable to read boot sector (logical sector size = %lu)",
389 p_pbr = (struct pbr *)sbi->pbr_bh->b_data;
394 /* mount the file system volume */
395 static int __exfat_fill_super(struct super_block *sb)
400 struct exfat_sb_info *sbi = EXFAT_SB(sb);
402 /* set block size to read super block */
403 sb_min_blocksize(sb, 512);
405 /* read boot sector */
406 sbi->pbr_bh = sb_bread(sb, 0);
408 exfat_msg(sb, KERN_ERR, "unable to read boot sector");
413 p_pbr = (struct pbr *)sbi->pbr_bh->b_data;
415 /* check the validity of PBR */
416 if (le16_to_cpu((p_pbr->signature)) != PBR_SIGNATURE) {
417 exfat_msg(sb, KERN_ERR, "invalid boot record signature");
423 /* check logical sector size */
424 p_pbr = exfat_read_pbr_with_logical_sector(sb);
431 * res_zero field must be filled with zero to prevent mounting
434 if (memchr_inv(p_pbr->bpb.f64.res_zero, 0,
435 sizeof(p_pbr->bpb.f64.res_zero))) {
440 p_bpb = (struct pbr64 *)p_pbr;
441 if (!p_bpb->bsx.num_fats) {
442 exfat_msg(sb, KERN_ERR, "bogus number of FAT structure");
447 sbi->sect_per_clus = 1 << p_bpb->bsx.sect_per_clus_bits;
448 sbi->sect_per_clus_bits = p_bpb->bsx.sect_per_clus_bits;
449 sbi->cluster_size_bits = sbi->sect_per_clus_bits + sb->s_blocksize_bits;
450 sbi->cluster_size = 1 << sbi->cluster_size_bits;
451 sbi->num_FAT_sectors = le32_to_cpu(p_bpb->bsx.fat_length);
452 sbi->FAT1_start_sector = le32_to_cpu(p_bpb->bsx.fat_offset);
453 sbi->FAT2_start_sector = p_bpb->bsx.num_fats == 1 ?
454 sbi->FAT1_start_sector :
455 sbi->FAT1_start_sector + sbi->num_FAT_sectors;
456 sbi->data_start_sector = le32_to_cpu(p_bpb->bsx.clu_offset);
457 sbi->num_sectors = le64_to_cpu(p_bpb->bsx.vol_length);
458 /* because the cluster index starts with 2 */
459 sbi->num_clusters = le32_to_cpu(p_bpb->bsx.clu_count) +
460 EXFAT_RESERVED_CLUSTERS;
462 sbi->root_dir = le32_to_cpu(p_bpb->bsx.root_cluster);
463 sbi->dentries_per_clu = 1 <<
464 (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
466 sbi->vol_flag = le16_to_cpu(p_bpb->bsx.vol_flags);
467 sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
468 sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
470 if (le16_to_cpu(p_bpb->bsx.vol_flags) & VOL_DIRTY) {
471 sbi->vol_flag |= VOL_DIRTY;
472 exfat_msg(sb, KERN_WARNING,
473 "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
476 /* exFAT file size is limited by a disk volume size */
477 sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
478 sbi->cluster_size_bits;
480 ret = exfat_create_upcase_table(sb);
482 exfat_msg(sb, KERN_ERR, "failed to load upcase table");
486 ret = exfat_load_bitmap(sb);
488 exfat_msg(sb, KERN_ERR, "failed to load alloc-bitmap");
489 goto free_upcase_table;
492 ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
494 exfat_msg(sb, KERN_ERR, "failed to scan clusters");
495 goto free_alloc_bitmap;
501 exfat_free_bitmap(sbi);
503 exfat_free_upcase_table(sbi);
509 static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
511 struct exfat_sb_info *sbi = sb->s_fs_info;
512 struct exfat_mount_options *opts = &sbi->options;
513 struct inode *root_inode;
516 if (opts->allow_utime == (unsigned short)-1)
517 opts->allow_utime = ~opts->fs_dmask & 0022;
520 struct request_queue *q = bdev_get_queue(sb->s_bdev);
522 if (!blk_queue_discard(q)) {
523 exfat_msg(sb, KERN_WARNING,
524 "mounting with \"discard\" option, but the device does not support discard");
529 sb->s_flags |= SB_NODIRATIME;
530 sb->s_magic = EXFAT_SUPER_MAGIC;
531 sb->s_op = &exfat_sops;
533 sb->s_time_gran = 10 * NSEC_PER_MSEC;
534 sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
535 sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
537 err = __exfat_fill_super(sb);
539 exfat_msg(sb, KERN_ERR, "failed to recognize exfat type");
543 /* set up enough so that it can read an inode */
546 if (!strcmp(sbi->options.iocharset, "utf8"))
549 sbi->nls_io = load_nls(sbi->options.iocharset);
551 exfat_msg(sb, KERN_ERR, "IO charset %s not found",
552 sbi->options.iocharset);
558 if (sbi->options.utf8)
559 sb->s_d_op = &exfat_utf8_dentry_ops;
561 sb->s_d_op = &exfat_dentry_ops;
563 root_inode = new_inode(sb);
565 exfat_msg(sb, KERN_ERR, "failed to allocate root inode.");
570 root_inode->i_ino = EXFAT_ROOT_INO;
571 inode_set_iversion(root_inode, 1);
572 err = exfat_read_root(root_inode);
574 exfat_msg(sb, KERN_ERR, "failed to initialize root inode.");
578 exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
579 insert_inode_hash(root_inode);
581 sb->s_root = d_make_root(root_inode);
583 exfat_msg(sb, KERN_ERR, "failed to get the root dentry");
595 exfat_free_upcase_table(sbi);
596 exfat_free_bitmap(sbi);
600 unload_nls(sbi->nls_io);
601 exfat_free_iocharset(sbi);
602 sb->s_fs_info = NULL;
607 static int exfat_get_tree(struct fs_context *fc)
609 return get_tree_bdev(fc, exfat_fill_super);
612 static void exfat_free(struct fs_context *fc)
614 kfree(fc->s_fs_info);
617 static const struct fs_context_operations exfat_context_ops = {
618 .parse_param = exfat_parse_param,
619 .get_tree = exfat_get_tree,
623 static int exfat_init_fs_context(struct fs_context *fc)
625 struct exfat_sb_info *sbi;
627 sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
631 mutex_init(&sbi->s_lock);
632 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
633 DEFAULT_RATELIMIT_BURST);
635 sbi->options.fs_uid = current_uid();
636 sbi->options.fs_gid = current_gid();
637 sbi->options.fs_fmask = current->fs->umask;
638 sbi->options.fs_dmask = current->fs->umask;
639 sbi->options.allow_utime = -1;
640 sbi->options.iocharset = exfat_default_iocharset;
641 sbi->options.errors = EXFAT_ERRORS_RO;
644 fc->ops = &exfat_context_ops;
648 static struct file_system_type exfat_fs_type = {
649 .owner = THIS_MODULE,
651 .init_fs_context = exfat_init_fs_context,
652 .parameters = exfat_parameters,
653 .kill_sb = kill_block_super,
654 .fs_flags = FS_REQUIRES_DEV,
657 static void exfat_inode_init_once(void *foo)
659 struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;
661 INIT_HLIST_NODE(&ei->i_hash_fat);
662 inode_init_once(&ei->vfs_inode);
665 static int __init init_exfat_fs(void)
669 err = exfat_cache_init();
673 exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
674 sizeof(struct exfat_inode_info),
675 0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
676 exfat_inode_init_once);
677 if (!exfat_inode_cachep) {
682 err = register_filesystem(&exfat_fs_type);
689 kmem_cache_destroy(exfat_inode_cachep);
691 exfat_cache_shutdown();
695 static void __exit exit_exfat_fs(void)
698 * Make sure all delayed rcu free inodes are flushed before we
702 kmem_cache_destroy(exfat_inode_cachep);
703 unregister_filesystem(&exfat_fs_type);
704 exfat_cache_shutdown();
707 module_init(init_exfat_fs);
708 module_exit(exit_exfat_fs);
710 MODULE_ALIAS_FS("exfat");
711 MODULE_LICENSE("GPL");
712 MODULE_DESCRIPTION("exFAT filesystem support");
713 MODULE_AUTHOR("Samsung Electronics Co., Ltd.");