1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. |
4 | */ |
5 | |
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> |
20 | #include <linux/magic.h> |
21 | |
22 | #include "exfat_raw.h" |
23 | #include "exfat_fs.h" |
24 | |
25 | static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET; |
26 | static struct kmem_cache *exfat_inode_cachep; |
27 | |
28 | static void exfat_free_iocharset(struct exfat_sb_info *sbi) |
29 | { |
30 | if (sbi->options.iocharset != exfat_default_iocharset) |
31 | kfree(objp: sbi->options.iocharset); |
32 | } |
33 | |
34 | static void exfat_put_super(struct super_block *sb) |
35 | { |
36 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
37 | |
38 | mutex_lock(&sbi->s_lock); |
39 | exfat_free_bitmap(sbi); |
40 | brelse(bh: sbi->boot_bh); |
41 | mutex_unlock(lock: &sbi->s_lock); |
42 | } |
43 | |
44 | static int exfat_sync_fs(struct super_block *sb, int wait) |
45 | { |
46 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
47 | int err = 0; |
48 | |
49 | if (!wait) |
50 | return 0; |
51 | |
52 | /* If there are some dirty buffers in the bdev inode */ |
53 | mutex_lock(&sbi->s_lock); |
54 | sync_blockdev(bdev: sb->s_bdev); |
55 | if (exfat_clear_volume_dirty(sb)) |
56 | err = -EIO; |
57 | mutex_unlock(lock: &sbi->s_lock); |
58 | return err; |
59 | } |
60 | |
61 | static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf) |
62 | { |
63 | struct super_block *sb = dentry->d_sb; |
64 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
65 | unsigned long long id = huge_encode_dev(dev: sb->s_bdev->bd_dev); |
66 | |
67 | if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) { |
68 | mutex_lock(&sbi->s_lock); |
69 | if (exfat_count_used_clusters(sb, ret_count: &sbi->used_clusters)) { |
70 | mutex_unlock(lock: &sbi->s_lock); |
71 | return -EIO; |
72 | } |
73 | mutex_unlock(lock: &sbi->s_lock); |
74 | } |
75 | |
76 | buf->f_type = sb->s_magic; |
77 | buf->f_bsize = sbi->cluster_size; |
78 | buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */ |
79 | buf->f_bfree = buf->f_blocks - sbi->used_clusters; |
80 | buf->f_bavail = buf->f_bfree; |
81 | buf->f_fsid = u64_to_fsid(v: id); |
82 | /* Unicode utf16 255 characters */ |
83 | buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE; |
84 | return 0; |
85 | } |
86 | |
87 | static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags) |
88 | { |
89 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
90 | struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data; |
91 | |
92 | /* retain persistent-flags */ |
93 | new_flags |= sbi->vol_flags_persistent; |
94 | |
95 | /* flags are not changed */ |
96 | if (sbi->vol_flags == new_flags) |
97 | return 0; |
98 | |
99 | sbi->vol_flags = new_flags; |
100 | |
101 | /* skip updating volume dirty flag, |
102 | * if this volume has been mounted with read-only |
103 | */ |
104 | if (sb_rdonly(sb)) |
105 | return 0; |
106 | |
107 | p_boot->vol_flags = cpu_to_le16(new_flags); |
108 | |
109 | set_buffer_uptodate(sbi->boot_bh); |
110 | mark_buffer_dirty(bh: sbi->boot_bh); |
111 | |
112 | __sync_dirty_buffer(bh: sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH); |
113 | |
114 | return 0; |
115 | } |
116 | |
117 | int exfat_set_volume_dirty(struct super_block *sb) |
118 | { |
119 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
120 | |
121 | return exfat_set_vol_flags(sb, new_flags: sbi->vol_flags | VOLUME_DIRTY); |
122 | } |
123 | |
124 | int exfat_clear_volume_dirty(struct super_block *sb) |
125 | { |
126 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
127 | |
128 | return exfat_set_vol_flags(sb, new_flags: sbi->vol_flags & ~VOLUME_DIRTY); |
129 | } |
130 | |
131 | static int exfat_show_options(struct seq_file *m, struct dentry *root) |
132 | { |
133 | struct super_block *sb = root->d_sb; |
134 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
135 | struct exfat_mount_options *opts = &sbi->options; |
136 | |
137 | /* Show partition info */ |
138 | if (!uid_eq(left: opts->fs_uid, GLOBAL_ROOT_UID)) |
139 | seq_printf(m, ",uid=%u" , |
140 | from_kuid_munged(&init_user_ns, opts->fs_uid)); |
141 | if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID)) |
142 | seq_printf(m, ",gid=%u" , |
143 | from_kgid_munged(&init_user_ns, opts->fs_gid)); |
144 | seq_printf(m, ",fmask=%04o,dmask=%04o" , opts->fs_fmask, opts->fs_dmask); |
145 | if (opts->allow_utime) |
146 | seq_printf(m, ",allow_utime=%04o" , opts->allow_utime); |
147 | if (opts->utf8) |
148 | seq_puts(m, ",iocharset=utf8" ); |
149 | else if (sbi->nls_io) |
150 | seq_printf(m, ",iocharset=%s" , sbi->nls_io->charset); |
151 | if (opts->errors == EXFAT_ERRORS_CONT) |
152 | seq_puts(m, ",errors=continue" ); |
153 | else if (opts->errors == EXFAT_ERRORS_PANIC) |
154 | seq_puts(m, ",errors=panic" ); |
155 | else |
156 | seq_puts(m, ",errors=remount-ro" ); |
157 | if (opts->discard) |
158 | seq_puts(m, ",discard" ); |
159 | if (opts->keep_last_dots) |
160 | seq_puts(m, ",keep_last_dots" ); |
161 | if (opts->sys_tz) |
162 | seq_puts(m, ",sys_tz" ); |
163 | else if (opts->time_offset) |
164 | seq_printf(m, ",time_offset=%d" , opts->time_offset); |
165 | if (opts->zero_size_dir) |
166 | seq_puts(m, ",zero_size_dir" ); |
167 | return 0; |
168 | } |
169 | |
170 | static struct inode *exfat_alloc_inode(struct super_block *sb) |
171 | { |
172 | struct exfat_inode_info *ei; |
173 | |
174 | ei = alloc_inode_sb(sb, cache: exfat_inode_cachep, GFP_NOFS); |
175 | if (!ei) |
176 | return NULL; |
177 | |
178 | init_rwsem(&ei->truncate_lock); |
179 | return &ei->vfs_inode; |
180 | } |
181 | |
182 | static void exfat_free_inode(struct inode *inode) |
183 | { |
184 | kmem_cache_free(s: exfat_inode_cachep, objp: EXFAT_I(inode)); |
185 | } |
186 | |
187 | static const struct super_operations exfat_sops = { |
188 | .alloc_inode = exfat_alloc_inode, |
189 | .free_inode = exfat_free_inode, |
190 | .write_inode = exfat_write_inode, |
191 | .evict_inode = exfat_evict_inode, |
192 | .put_super = exfat_put_super, |
193 | .sync_fs = exfat_sync_fs, |
194 | .statfs = exfat_statfs, |
195 | .show_options = exfat_show_options, |
196 | }; |
197 | |
198 | enum { |
199 | Opt_uid, |
200 | Opt_gid, |
201 | Opt_umask, |
202 | Opt_dmask, |
203 | Opt_fmask, |
204 | Opt_allow_utime, |
205 | Opt_charset, |
206 | Opt_errors, |
207 | Opt_discard, |
208 | Opt_keep_last_dots, |
209 | Opt_sys_tz, |
210 | Opt_time_offset, |
211 | Opt_zero_size_dir, |
212 | |
213 | /* Deprecated options */ |
214 | Opt_utf8, |
215 | Opt_debug, |
216 | Opt_namecase, |
217 | Opt_codepage, |
218 | }; |
219 | |
220 | static const struct constant_table exfat_param_enums[] = { |
221 | { "continue" , EXFAT_ERRORS_CONT }, |
222 | { "panic" , EXFAT_ERRORS_PANIC }, |
223 | { "remount-ro" , EXFAT_ERRORS_RO }, |
224 | {} |
225 | }; |
226 | |
227 | static const struct fs_parameter_spec exfat_parameters[] = { |
228 | fsparam_u32("uid" , Opt_uid), |
229 | fsparam_u32("gid" , Opt_gid), |
230 | fsparam_u32oct("umask" , Opt_umask), |
231 | fsparam_u32oct("dmask" , Opt_dmask), |
232 | fsparam_u32oct("fmask" , Opt_fmask), |
233 | fsparam_u32oct("allow_utime" , Opt_allow_utime), |
234 | fsparam_string("iocharset" , Opt_charset), |
235 | fsparam_enum("errors" , Opt_errors, exfat_param_enums), |
236 | fsparam_flag("discard" , Opt_discard), |
237 | fsparam_flag("keep_last_dots" , Opt_keep_last_dots), |
238 | fsparam_flag("sys_tz" , Opt_sys_tz), |
239 | fsparam_s32("time_offset" , Opt_time_offset), |
240 | fsparam_flag("zero_size_dir" , Opt_zero_size_dir), |
241 | __fsparam(NULL, "utf8" , Opt_utf8, fs_param_deprecated, |
242 | NULL), |
243 | __fsparam(NULL, "debug" , Opt_debug, fs_param_deprecated, |
244 | NULL), |
245 | __fsparam(fs_param_is_u32, "namecase" , Opt_namecase, |
246 | fs_param_deprecated, NULL), |
247 | __fsparam(fs_param_is_u32, "codepage" , Opt_codepage, |
248 | fs_param_deprecated, NULL), |
249 | {} |
250 | }; |
251 | |
252 | static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param) |
253 | { |
254 | struct exfat_sb_info *sbi = fc->s_fs_info; |
255 | struct exfat_mount_options *opts = &sbi->options; |
256 | struct fs_parse_result result; |
257 | int opt; |
258 | |
259 | opt = fs_parse(fc, desc: exfat_parameters, param, result: &result); |
260 | if (opt < 0) |
261 | return opt; |
262 | |
263 | switch (opt) { |
264 | case Opt_uid: |
265 | opts->fs_uid = make_kuid(current_user_ns(), uid: result.uint_32); |
266 | break; |
267 | case Opt_gid: |
268 | opts->fs_gid = make_kgid(current_user_ns(), gid: result.uint_32); |
269 | break; |
270 | case Opt_umask: |
271 | opts->fs_fmask = result.uint_32; |
272 | opts->fs_dmask = result.uint_32; |
273 | break; |
274 | case Opt_dmask: |
275 | opts->fs_dmask = result.uint_32; |
276 | break; |
277 | case Opt_fmask: |
278 | opts->fs_fmask = result.uint_32; |
279 | break; |
280 | case Opt_allow_utime: |
281 | opts->allow_utime = result.uint_32 & 0022; |
282 | break; |
283 | case Opt_charset: |
284 | exfat_free_iocharset(sbi); |
285 | opts->iocharset = param->string; |
286 | param->string = NULL; |
287 | break; |
288 | case Opt_errors: |
289 | opts->errors = result.uint_32; |
290 | break; |
291 | case Opt_discard: |
292 | opts->discard = 1; |
293 | break; |
294 | case Opt_keep_last_dots: |
295 | opts->keep_last_dots = 1; |
296 | break; |
297 | case Opt_sys_tz: |
298 | opts->sys_tz = 1; |
299 | break; |
300 | case Opt_time_offset: |
301 | /* |
302 | * Make the limit 24 just in case someone invents something |
303 | * unusual. |
304 | */ |
305 | if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60) |
306 | return -EINVAL; |
307 | opts->time_offset = result.int_32; |
308 | break; |
309 | case Opt_zero_size_dir: |
310 | opts->zero_size_dir = true; |
311 | break; |
312 | case Opt_utf8: |
313 | case Opt_debug: |
314 | case Opt_namecase: |
315 | case Opt_codepage: |
316 | break; |
317 | default: |
318 | return -EINVAL; |
319 | } |
320 | |
321 | return 0; |
322 | } |
323 | |
324 | static void exfat_hash_init(struct super_block *sb) |
325 | { |
326 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
327 | int i; |
328 | |
329 | spin_lock_init(&sbi->inode_hash_lock); |
330 | for (i = 0; i < EXFAT_HASH_SIZE; i++) |
331 | INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); |
332 | } |
333 | |
334 | static int exfat_read_root(struct inode *inode) |
335 | { |
336 | struct super_block *sb = inode->i_sb; |
337 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
338 | struct exfat_inode_info *ei = EXFAT_I(inode); |
339 | struct exfat_chain cdir; |
340 | int num_subdirs, num_clu = 0; |
341 | |
342 | exfat_chain_set(ec: &ei->dir, dir: sbi->root_dir, size: 0, ALLOC_FAT_CHAIN); |
343 | ei->entry = -1; |
344 | ei->start_clu = sbi->root_dir; |
345 | ei->flags = ALLOC_FAT_CHAIN; |
346 | ei->type = TYPE_DIR; |
347 | ei->version = 0; |
348 | ei->hint_bmap.off = EXFAT_EOF_CLUSTER; |
349 | ei->hint_stat.eidx = 0; |
350 | ei->hint_stat.clu = sbi->root_dir; |
351 | ei->hint_femp.eidx = EXFAT_HINT_NONE; |
352 | |
353 | exfat_chain_set(ec: &cdir, dir: sbi->root_dir, size: 0, ALLOC_FAT_CHAIN); |
354 | if (exfat_count_num_clusters(sb, p_chain: &cdir, ret_count: &num_clu)) |
355 | return -EIO; |
356 | i_size_write(inode, i_size: num_clu << sbi->cluster_size_bits); |
357 | |
358 | num_subdirs = exfat_count_dir_entries(sb, p_dir: &cdir); |
359 | if (num_subdirs < 0) |
360 | return -EIO; |
361 | set_nlink(inode, nlink: num_subdirs + EXFAT_MIN_SUBDIR); |
362 | |
363 | inode->i_uid = sbi->options.fs_uid; |
364 | inode->i_gid = sbi->options.fs_gid; |
365 | inode_inc_iversion(inode); |
366 | inode->i_generation = 0; |
367 | inode->i_mode = exfat_make_mode(sbi, EXFAT_ATTR_SUBDIR, mode: 0777); |
368 | inode->i_op = &exfat_dir_inode_operations; |
369 | inode->i_fop = &exfat_dir_operations; |
370 | |
371 | inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9; |
372 | ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff; |
373 | ei->i_size_aligned = i_size_read(inode); |
374 | ei->i_size_ondisk = i_size_read(inode); |
375 | |
376 | exfat_save_attr(inode, EXFAT_ATTR_SUBDIR); |
377 | ei->i_crtime = simple_inode_init_ts(inode); |
378 | exfat_truncate_inode_atime(inode); |
379 | return 0; |
380 | } |
381 | |
382 | static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect) |
383 | { |
384 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
385 | |
386 | if (!is_power_of_2(n: logical_sect)) { |
387 | exfat_err(sb, "bogus logical sector size %u" , logical_sect); |
388 | return -EIO; |
389 | } |
390 | |
391 | if (logical_sect < sb->s_blocksize) { |
392 | exfat_err(sb, "logical sector size too small for device (logical sector size = %u)" , |
393 | logical_sect); |
394 | return -EIO; |
395 | } |
396 | |
397 | if (logical_sect > sb->s_blocksize) { |
398 | brelse(bh: sbi->boot_bh); |
399 | sbi->boot_bh = NULL; |
400 | |
401 | if (!sb_set_blocksize(sb, logical_sect)) { |
402 | exfat_err(sb, "unable to set blocksize %u" , |
403 | logical_sect); |
404 | return -EIO; |
405 | } |
406 | sbi->boot_bh = sb_bread(sb, block: 0); |
407 | if (!sbi->boot_bh) { |
408 | exfat_err(sb, "unable to read boot sector (logical sector size = %lu)" , |
409 | sb->s_blocksize); |
410 | return -EIO; |
411 | } |
412 | } |
413 | return 0; |
414 | } |
415 | |
416 | static int exfat_read_boot_sector(struct super_block *sb) |
417 | { |
418 | struct boot_sector *p_boot; |
419 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
420 | |
421 | /* set block size to read super block */ |
422 | sb_min_blocksize(sb, 512); |
423 | |
424 | /* read boot sector */ |
425 | sbi->boot_bh = sb_bread(sb, block: 0); |
426 | if (!sbi->boot_bh) { |
427 | exfat_err(sb, "unable to read boot sector" ); |
428 | return -EIO; |
429 | } |
430 | p_boot = (struct boot_sector *)sbi->boot_bh->b_data; |
431 | |
432 | /* check the validity of BOOT */ |
433 | if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) { |
434 | exfat_err(sb, "invalid boot record signature" ); |
435 | return -EINVAL; |
436 | } |
437 | |
438 | if (memcmp(p: p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) { |
439 | exfat_err(sb, "invalid fs_name" ); /* fs_name may unprintable */ |
440 | return -EINVAL; |
441 | } |
442 | |
443 | /* |
444 | * must_be_zero field must be filled with zero to prevent mounting |
445 | * from FAT volume. |
446 | */ |
447 | if (memchr_inv(p: p_boot->must_be_zero, c: 0, size: sizeof(p_boot->must_be_zero))) |
448 | return -EINVAL; |
449 | |
450 | if (p_boot->num_fats != 1 && p_boot->num_fats != 2) { |
451 | exfat_err(sb, "bogus number of FAT structure" ); |
452 | return -EINVAL; |
453 | } |
454 | |
455 | /* |
456 | * sect_size_bits could be at least 9 and at most 12. |
457 | */ |
458 | if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS || |
459 | p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) { |
460 | exfat_err(sb, "bogus sector size bits : %u" , |
461 | p_boot->sect_size_bits); |
462 | return -EINVAL; |
463 | } |
464 | |
465 | /* |
466 | * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits. |
467 | */ |
468 | if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) { |
469 | exfat_err(sb, "bogus sectors bits per cluster : %u" , |
470 | p_boot->sect_per_clus_bits); |
471 | return -EINVAL; |
472 | } |
473 | |
474 | sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits; |
475 | sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits; |
476 | sbi->cluster_size_bits = p_boot->sect_per_clus_bits + |
477 | p_boot->sect_size_bits; |
478 | sbi->cluster_size = 1 << sbi->cluster_size_bits; |
479 | sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length); |
480 | sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset); |
481 | sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset); |
482 | if (p_boot->num_fats == 2) |
483 | sbi->FAT2_start_sector += sbi->num_FAT_sectors; |
484 | sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset); |
485 | sbi->num_sectors = le64_to_cpu(p_boot->vol_length); |
486 | /* because the cluster index starts with 2 */ |
487 | sbi->num_clusters = le32_to_cpu(p_boot->clu_count) + |
488 | EXFAT_RESERVED_CLUSTERS; |
489 | |
490 | sbi->root_dir = le32_to_cpu(p_boot->root_cluster); |
491 | sbi->dentries_per_clu = 1 << |
492 | (sbi->cluster_size_bits - DENTRY_SIZE_BITS); |
493 | |
494 | sbi->vol_flags = le16_to_cpu(p_boot->vol_flags); |
495 | sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE); |
496 | sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER; |
497 | sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED; |
498 | |
499 | /* check consistencies */ |
500 | if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits < |
501 | (u64)sbi->num_clusters * 4) { |
502 | exfat_err(sb, "bogus fat length" ); |
503 | return -EINVAL; |
504 | } |
505 | |
506 | if (sbi->data_start_sector < |
507 | (u64)sbi->FAT1_start_sector + |
508 | (u64)sbi->num_FAT_sectors * p_boot->num_fats) { |
509 | exfat_err(sb, "bogus data start sector" ); |
510 | return -EINVAL; |
511 | } |
512 | |
513 | if (sbi->vol_flags & VOLUME_DIRTY) |
514 | exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck." ); |
515 | if (sbi->vol_flags & MEDIA_FAILURE) |
516 | exfat_warn(sb, "Medium has reported failures. Some data may be lost." ); |
517 | |
518 | /* exFAT file size is limited by a disk volume size */ |
519 | sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) << |
520 | sbi->cluster_size_bits; |
521 | |
522 | /* check logical sector size */ |
523 | if (exfat_calibrate_blocksize(sb, logical_sect: 1 << p_boot->sect_size_bits)) |
524 | return -EIO; |
525 | |
526 | return 0; |
527 | } |
528 | |
529 | static int exfat_verify_boot_region(struct super_block *sb) |
530 | { |
531 | struct buffer_head *bh = NULL; |
532 | u32 chksum = 0; |
533 | __le32 *p_sig, *p_chksum; |
534 | int sn, i; |
535 | |
536 | /* read boot sector sub-regions */ |
537 | for (sn = 0; sn < 11; sn++) { |
538 | bh = sb_bread(sb, block: sn); |
539 | if (!bh) |
540 | return -EIO; |
541 | |
542 | if (sn != 0 && sn <= 8) { |
543 | /* extended boot sector sub-regions */ |
544 | p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4]; |
545 | if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE) |
546 | exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x" , |
547 | sn, le32_to_cpu(*p_sig)); |
548 | } |
549 | |
550 | chksum = exfat_calc_chksum32(data: bh->b_data, len: sb->s_blocksize, |
551 | chksum, type: sn ? CS_DEFAULT : CS_BOOT_SECTOR); |
552 | brelse(bh); |
553 | } |
554 | |
555 | /* boot checksum sub-regions */ |
556 | bh = sb_bread(sb, block: sn); |
557 | if (!bh) |
558 | return -EIO; |
559 | |
560 | for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) { |
561 | p_chksum = (__le32 *)&bh->b_data[i]; |
562 | if (le32_to_cpu(*p_chksum) != chksum) { |
563 | exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)" , |
564 | le32_to_cpu(*p_chksum), chksum); |
565 | brelse(bh); |
566 | return -EINVAL; |
567 | } |
568 | } |
569 | brelse(bh); |
570 | return 0; |
571 | } |
572 | |
573 | /* mount the file system volume */ |
574 | static int __exfat_fill_super(struct super_block *sb) |
575 | { |
576 | int ret; |
577 | struct exfat_sb_info *sbi = EXFAT_SB(sb); |
578 | |
579 | ret = exfat_read_boot_sector(sb); |
580 | if (ret) { |
581 | exfat_err(sb, "failed to read boot sector" ); |
582 | goto free_bh; |
583 | } |
584 | |
585 | ret = exfat_verify_boot_region(sb); |
586 | if (ret) { |
587 | exfat_err(sb, "invalid boot region" ); |
588 | goto free_bh; |
589 | } |
590 | |
591 | ret = exfat_create_upcase_table(sb); |
592 | if (ret) { |
593 | exfat_err(sb, "failed to load upcase table" ); |
594 | goto free_bh; |
595 | } |
596 | |
597 | ret = exfat_load_bitmap(sb); |
598 | if (ret) { |
599 | exfat_err(sb, "failed to load alloc-bitmap" ); |
600 | goto free_bh; |
601 | } |
602 | |
603 | ret = exfat_count_used_clusters(sb, ret_count: &sbi->used_clusters); |
604 | if (ret) { |
605 | exfat_err(sb, "failed to scan clusters" ); |
606 | goto free_alloc_bitmap; |
607 | } |
608 | |
609 | return 0; |
610 | |
611 | free_alloc_bitmap: |
612 | exfat_free_bitmap(sbi); |
613 | free_bh: |
614 | brelse(bh: sbi->boot_bh); |
615 | return ret; |
616 | } |
617 | |
618 | static int exfat_fill_super(struct super_block *sb, struct fs_context *fc) |
619 | { |
620 | struct exfat_sb_info *sbi = sb->s_fs_info; |
621 | struct exfat_mount_options *opts = &sbi->options; |
622 | struct inode *root_inode; |
623 | int err; |
624 | |
625 | if (opts->allow_utime == (unsigned short)-1) |
626 | opts->allow_utime = ~opts->fs_dmask & 0022; |
627 | |
628 | if (opts->discard && !bdev_max_discard_sectors(bdev: sb->s_bdev)) { |
629 | exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard" ); |
630 | opts->discard = 0; |
631 | } |
632 | |
633 | sb->s_flags |= SB_NODIRATIME; |
634 | sb->s_magic = EXFAT_SUPER_MAGIC; |
635 | sb->s_op = &exfat_sops; |
636 | |
637 | sb->s_time_gran = 10 * NSEC_PER_MSEC; |
638 | sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS; |
639 | sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS; |
640 | |
641 | err = __exfat_fill_super(sb); |
642 | if (err) { |
643 | exfat_err(sb, "failed to recognize exfat type" ); |
644 | goto check_nls_io; |
645 | } |
646 | |
647 | /* set up enough so that it can read an inode */ |
648 | exfat_hash_init(sb); |
649 | |
650 | if (!strcmp(sbi->options.iocharset, "utf8" )) |
651 | opts->utf8 = 1; |
652 | else { |
653 | sbi->nls_io = load_nls(charset: sbi->options.iocharset); |
654 | if (!sbi->nls_io) { |
655 | exfat_err(sb, "IO charset %s not found" , |
656 | sbi->options.iocharset); |
657 | err = -EINVAL; |
658 | goto free_table; |
659 | } |
660 | } |
661 | |
662 | if (sbi->options.utf8) |
663 | sb->s_d_op = &exfat_utf8_dentry_ops; |
664 | else |
665 | sb->s_d_op = &exfat_dentry_ops; |
666 | |
667 | root_inode = new_inode(sb); |
668 | if (!root_inode) { |
669 | exfat_err(sb, "failed to allocate root inode" ); |
670 | err = -ENOMEM; |
671 | goto free_table; |
672 | } |
673 | |
674 | root_inode->i_ino = EXFAT_ROOT_INO; |
675 | inode_set_iversion(inode: root_inode, val: 1); |
676 | err = exfat_read_root(inode: root_inode); |
677 | if (err) { |
678 | exfat_err(sb, "failed to initialize root inode" ); |
679 | goto put_inode; |
680 | } |
681 | |
682 | exfat_hash_inode(inode: root_inode, i_pos: EXFAT_I(inode: root_inode)->i_pos); |
683 | insert_inode_hash(inode: root_inode); |
684 | |
685 | sb->s_root = d_make_root(root_inode); |
686 | if (!sb->s_root) { |
687 | exfat_err(sb, "failed to get the root dentry" ); |
688 | err = -ENOMEM; |
689 | goto free_table; |
690 | } |
691 | |
692 | return 0; |
693 | |
694 | put_inode: |
695 | iput(root_inode); |
696 | sb->s_root = NULL; |
697 | |
698 | free_table: |
699 | exfat_free_bitmap(sbi); |
700 | brelse(bh: sbi->boot_bh); |
701 | |
702 | check_nls_io: |
703 | return err; |
704 | } |
705 | |
706 | static int exfat_get_tree(struct fs_context *fc) |
707 | { |
708 | return get_tree_bdev(fc, fill_super: exfat_fill_super); |
709 | } |
710 | |
711 | static void exfat_free_sbi(struct exfat_sb_info *sbi) |
712 | { |
713 | exfat_free_iocharset(sbi); |
714 | kfree(objp: sbi); |
715 | } |
716 | |
717 | static void exfat_free(struct fs_context *fc) |
718 | { |
719 | struct exfat_sb_info *sbi = fc->s_fs_info; |
720 | |
721 | if (sbi) |
722 | exfat_free_sbi(sbi); |
723 | } |
724 | |
725 | static int exfat_reconfigure(struct fs_context *fc) |
726 | { |
727 | fc->sb_flags |= SB_NODIRATIME; |
728 | |
729 | /* volume flag will be updated in exfat_sync_fs */ |
730 | sync_filesystem(fc->root->d_sb); |
731 | return 0; |
732 | } |
733 | |
734 | static const struct fs_context_operations exfat_context_ops = { |
735 | .parse_param = exfat_parse_param, |
736 | .get_tree = exfat_get_tree, |
737 | .free = exfat_free, |
738 | .reconfigure = exfat_reconfigure, |
739 | }; |
740 | |
741 | static int exfat_init_fs_context(struct fs_context *fc) |
742 | { |
743 | struct exfat_sb_info *sbi; |
744 | |
745 | sbi = kzalloc(size: sizeof(struct exfat_sb_info), GFP_KERNEL); |
746 | if (!sbi) |
747 | return -ENOMEM; |
748 | |
749 | mutex_init(&sbi->s_lock); |
750 | mutex_init(&sbi->bitmap_lock); |
751 | ratelimit_state_init(rs: &sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL, |
752 | DEFAULT_RATELIMIT_BURST); |
753 | |
754 | sbi->options.fs_uid = current_uid(); |
755 | sbi->options.fs_gid = current_gid(); |
756 | sbi->options.fs_fmask = current->fs->umask; |
757 | sbi->options.fs_dmask = current->fs->umask; |
758 | sbi->options.allow_utime = -1; |
759 | sbi->options.iocharset = exfat_default_iocharset; |
760 | sbi->options.errors = EXFAT_ERRORS_RO; |
761 | |
762 | fc->s_fs_info = sbi; |
763 | fc->ops = &exfat_context_ops; |
764 | return 0; |
765 | } |
766 | |
767 | static void delayed_free(struct rcu_head *p) |
768 | { |
769 | struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu); |
770 | |
771 | unload_nls(sbi->nls_io); |
772 | exfat_free_upcase_table(sbi); |
773 | exfat_free_sbi(sbi); |
774 | } |
775 | |
776 | static void exfat_kill_sb(struct super_block *sb) |
777 | { |
778 | struct exfat_sb_info *sbi = sb->s_fs_info; |
779 | |
780 | kill_block_super(sb); |
781 | if (sbi) |
782 | call_rcu(head: &sbi->rcu, func: delayed_free); |
783 | } |
784 | |
785 | static struct file_system_type exfat_fs_type = { |
786 | .owner = THIS_MODULE, |
787 | .name = "exfat" , |
788 | .init_fs_context = exfat_init_fs_context, |
789 | .parameters = exfat_parameters, |
790 | .kill_sb = exfat_kill_sb, |
791 | .fs_flags = FS_REQUIRES_DEV, |
792 | }; |
793 | |
794 | static void exfat_inode_init_once(void *foo) |
795 | { |
796 | struct exfat_inode_info *ei = (struct exfat_inode_info *)foo; |
797 | |
798 | spin_lock_init(&ei->cache_lru_lock); |
799 | ei->nr_caches = 0; |
800 | ei->cache_valid_id = EXFAT_CACHE_VALID + 1; |
801 | INIT_LIST_HEAD(list: &ei->cache_lru); |
802 | INIT_HLIST_NODE(h: &ei->i_hash_fat); |
803 | inode_init_once(&ei->vfs_inode); |
804 | } |
805 | |
806 | static int __init init_exfat_fs(void) |
807 | { |
808 | int err; |
809 | |
810 | err = exfat_cache_init(); |
811 | if (err) |
812 | return err; |
813 | |
814 | exfat_inode_cachep = kmem_cache_create(name: "exfat_inode_cache" , |
815 | size: sizeof(struct exfat_inode_info), |
816 | align: 0, SLAB_RECLAIM_ACCOUNT, |
817 | ctor: exfat_inode_init_once); |
818 | if (!exfat_inode_cachep) { |
819 | err = -ENOMEM; |
820 | goto shutdown_cache; |
821 | } |
822 | |
823 | err = register_filesystem(&exfat_fs_type); |
824 | if (err) |
825 | goto destroy_cache; |
826 | |
827 | return 0; |
828 | |
829 | destroy_cache: |
830 | kmem_cache_destroy(s: exfat_inode_cachep); |
831 | shutdown_cache: |
832 | exfat_cache_shutdown(); |
833 | return err; |
834 | } |
835 | |
836 | static void __exit exit_exfat_fs(void) |
837 | { |
838 | /* |
839 | * Make sure all delayed rcu free inodes are flushed before we |
840 | * destroy cache. |
841 | */ |
842 | rcu_barrier(); |
843 | kmem_cache_destroy(s: exfat_inode_cachep); |
844 | unregister_filesystem(&exfat_fs_type); |
845 | exfat_cache_shutdown(); |
846 | } |
847 | |
848 | module_init(init_exfat_fs); |
849 | module_exit(exit_exfat_fs); |
850 | |
851 | MODULE_ALIAS_FS("exfat" ); |
852 | MODULE_LICENSE("GPL" ); |
853 | MODULE_DESCRIPTION("exFAT filesystem support" ); |
854 | MODULE_AUTHOR("Samsung Electronics Co., Ltd." ); |
855 | |