1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2017-2018 HUAWEI, Inc.
4 * https://www.huawei.com/
5 * Created by Gao Xiang <gaoxiang25@huawei.com>
6 */
7 #include <linux/module.h>
8 #include <linux/buffer_head.h>
9 #include <linux/statfs.h>
10 #include <linux/parser.h>
11 #include <linux/seq_file.h>
12 #include <linux/crc32c.h>
13 #include <linux/fs_context.h>
14 #include <linux/fs_parser.h>
15 #include <linux/dax.h>
16 #include "xattr.h"
17
18 #define CREATE_TRACE_POINTS
19 #include <trace/events/erofs.h>
20
21 static struct kmem_cache *erofs_inode_cachep __read_mostly;
22
_erofs_err(struct super_block * sb,const char * function,const char * fmt,...)23 void _erofs_err(struct super_block *sb, const char *function,
24 const char *fmt, ...)
25 {
26 struct va_format vaf;
27 va_list args;
28
29 va_start(args, fmt);
30
31 vaf.fmt = fmt;
32 vaf.va = &args;
33
34 pr_err("(device %s): %s: %pV", sb->s_id, function, &vaf);
35 va_end(args);
36 }
37
_erofs_info(struct super_block * sb,const char * function,const char * fmt,...)38 void _erofs_info(struct super_block *sb, const char *function,
39 const char *fmt, ...)
40 {
41 struct va_format vaf;
42 va_list args;
43
44 va_start(args, fmt);
45
46 vaf.fmt = fmt;
47 vaf.va = &args;
48
49 pr_info("(device %s): %pV", sb->s_id, &vaf);
50 va_end(args);
51 }
52
erofs_superblock_csum_verify(struct super_block * sb,void * sbdata)53 static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata)
54 {
55 struct erofs_super_block *dsb;
56 u32 expected_crc, crc;
57
58 dsb = kmemdup(sbdata + EROFS_SUPER_OFFSET,
59 EROFS_BLKSIZ - EROFS_SUPER_OFFSET, GFP_KERNEL);
60 if (!dsb)
61 return -ENOMEM;
62
63 expected_crc = le32_to_cpu(dsb->checksum);
64 dsb->checksum = 0;
65 /* to allow for x86 boot sectors and other oddities. */
66 crc = crc32c(~0, dsb, EROFS_BLKSIZ - EROFS_SUPER_OFFSET);
67 kfree(dsb);
68
69 if (crc != expected_crc) {
70 erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected",
71 crc, expected_crc);
72 return -EBADMSG;
73 }
74 return 0;
75 }
76
erofs_inode_init_once(void * ptr)77 static void erofs_inode_init_once(void *ptr)
78 {
79 struct erofs_inode *vi = ptr;
80
81 inode_init_once(&vi->vfs_inode);
82 }
83
erofs_alloc_inode(struct super_block * sb)84 static struct inode *erofs_alloc_inode(struct super_block *sb)
85 {
86 struct erofs_inode *vi =
87 kmem_cache_alloc(erofs_inode_cachep, GFP_KERNEL);
88
89 if (!vi)
90 return NULL;
91
92 /* zero out everything except vfs_inode */
93 memset(vi, 0, offsetof(struct erofs_inode, vfs_inode));
94 return &vi->vfs_inode;
95 }
96
erofs_free_inode(struct inode * inode)97 static void erofs_free_inode(struct inode *inode)
98 {
99 struct erofs_inode *vi = EROFS_I(inode);
100
101 /* be careful of RCU symlink path */
102 if (inode->i_op == &erofs_fast_symlink_iops)
103 kfree(inode->i_link);
104 kfree(vi->xattr_shared_xattrs);
105
106 kmem_cache_free(erofs_inode_cachep, vi);
107 }
108
check_layout_compatibility(struct super_block * sb,struct erofs_super_block * dsb)109 static bool check_layout_compatibility(struct super_block *sb,
110 struct erofs_super_block *dsb)
111 {
112 const unsigned int feature = le32_to_cpu(dsb->feature_incompat);
113
114 EROFS_SB(sb)->feature_incompat = feature;
115
116 /* check if current kernel meets all mandatory requirements */
117 if (feature & (~EROFS_ALL_FEATURE_INCOMPAT)) {
118 erofs_err(sb,
119 "unidentified incompatible feature %x, please upgrade kernel version",
120 feature & ~EROFS_ALL_FEATURE_INCOMPAT);
121 return false;
122 }
123 return true;
124 }
125
126 #ifdef CONFIG_EROFS_FS_ZIP
127 /* read variable-sized metadata, offset will be aligned by 4-byte */
erofs_read_metadata(struct super_block * sb,struct page ** pagep,erofs_off_t * offset,int * lengthp)128 static void *erofs_read_metadata(struct super_block *sb, struct page **pagep,
129 erofs_off_t *offset, int *lengthp)
130 {
131 struct page *page = *pagep;
132 u8 *buffer, *ptr;
133 int len, i, cnt;
134 erofs_blk_t blk;
135
136 *offset = round_up(*offset, 4);
137 blk = erofs_blknr(*offset);
138
139 if (!page || page->index != blk) {
140 if (page) {
141 unlock_page(page);
142 put_page(page);
143 }
144 page = erofs_get_meta_page(sb, blk);
145 if (IS_ERR(page))
146 goto err_nullpage;
147 }
148
149 ptr = kmap(page);
150 len = le16_to_cpu(*(__le16 *)&ptr[erofs_blkoff(*offset)]);
151 if (!len)
152 len = U16_MAX + 1;
153 buffer = kmalloc(len, GFP_KERNEL);
154 if (!buffer) {
155 buffer = ERR_PTR(-ENOMEM);
156 goto out;
157 }
158 *offset += sizeof(__le16);
159 *lengthp = len;
160
161 for (i = 0; i < len; i += cnt) {
162 cnt = min(EROFS_BLKSIZ - (int)erofs_blkoff(*offset), len - i);
163 blk = erofs_blknr(*offset);
164
165 if (!page || page->index != blk) {
166 if (page) {
167 kunmap(page);
168 unlock_page(page);
169 put_page(page);
170 }
171 page = erofs_get_meta_page(sb, blk);
172 if (IS_ERR(page)) {
173 kfree(buffer);
174 goto err_nullpage;
175 }
176 ptr = kmap(page);
177 }
178 memcpy(buffer + i, ptr + erofs_blkoff(*offset), cnt);
179 *offset += cnt;
180 }
181 out:
182 kunmap(page);
183 *pagep = page;
184 return buffer;
185 err_nullpage:
186 *pagep = NULL;
187 return page;
188 }
189
erofs_load_compr_cfgs(struct super_block * sb,struct erofs_super_block * dsb)190 static int erofs_load_compr_cfgs(struct super_block *sb,
191 struct erofs_super_block *dsb)
192 {
193 struct erofs_sb_info *sbi;
194 struct page *page;
195 unsigned int algs, alg;
196 erofs_off_t offset;
197 int size, ret;
198
199 sbi = EROFS_SB(sb);
200 sbi->available_compr_algs = le16_to_cpu(dsb->u1.available_compr_algs);
201
202 if (sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS) {
203 erofs_err(sb, "try to load compressed fs with unsupported algorithms %x",
204 sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS);
205 return -EINVAL;
206 }
207
208 offset = EROFS_SUPER_OFFSET + sbi->sb_size;
209 page = NULL;
210 alg = 0;
211 ret = 0;
212
213 for (algs = sbi->available_compr_algs; algs; algs >>= 1, ++alg) {
214 void *data;
215
216 if (!(algs & 1))
217 continue;
218
219 data = erofs_read_metadata(sb, &page, &offset, &size);
220 if (IS_ERR(data)) {
221 ret = PTR_ERR(data);
222 goto err;
223 }
224
225 switch (alg) {
226 case Z_EROFS_COMPRESSION_LZ4:
227 ret = z_erofs_load_lz4_config(sb, dsb, data, size);
228 break;
229 default:
230 DBG_BUGON(1);
231 ret = -EFAULT;
232 }
233 kfree(data);
234 if (ret)
235 goto err;
236 }
237 err:
238 if (page) {
239 unlock_page(page);
240 put_page(page);
241 }
242 return ret;
243 }
244 #else
erofs_load_compr_cfgs(struct super_block * sb,struct erofs_super_block * dsb)245 static int erofs_load_compr_cfgs(struct super_block *sb,
246 struct erofs_super_block *dsb)
247 {
248 if (dsb->u1.available_compr_algs) {
249 erofs_err(sb, "try to load compressed fs when compression is disabled");
250 return -EINVAL;
251 }
252 return 0;
253 }
254 #endif
255
erofs_read_superblock(struct super_block * sb)256 static int erofs_read_superblock(struct super_block *sb)
257 {
258 struct erofs_sb_info *sbi;
259 struct page *page;
260 struct erofs_super_block *dsb;
261 unsigned int blkszbits;
262 void *data;
263 int ret;
264
265 page = read_mapping_page(sb->s_bdev->bd_inode->i_mapping, 0, NULL);
266 if (IS_ERR(page)) {
267 erofs_err(sb, "cannot read erofs superblock");
268 return PTR_ERR(page);
269 }
270
271 sbi = EROFS_SB(sb);
272
273 data = kmap(page);
274 dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET);
275
276 ret = -EINVAL;
277 if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) {
278 erofs_err(sb, "cannot find valid erofs superblock");
279 goto out;
280 }
281
282 sbi->feature_compat = le32_to_cpu(dsb->feature_compat);
283 if (erofs_sb_has_sb_chksum(sbi)) {
284 ret = erofs_superblock_csum_verify(sb, data);
285 if (ret)
286 goto out;
287 }
288
289 ret = -EINVAL;
290 blkszbits = dsb->blkszbits;
291 /* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */
292 if (blkszbits != LOG_BLOCK_SIZE) {
293 erofs_err(sb, "blkszbits %u isn't supported on this platform",
294 blkszbits);
295 goto out;
296 }
297
298 if (!check_layout_compatibility(sb, dsb))
299 goto out;
300
301 sbi->sb_size = 128 + dsb->sb_extslots * EROFS_SB_EXTSLOT_SIZE;
302 if (sbi->sb_size > EROFS_BLKSIZ) {
303 erofs_err(sb, "invalid sb_extslots %u (more than a fs block)",
304 sbi->sb_size);
305 goto out;
306 }
307 sbi->blocks = le32_to_cpu(dsb->blocks);
308 sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr);
309 #ifdef CONFIG_EROFS_FS_XATTR
310 sbi->xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr);
311 #endif
312 sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact));
313 sbi->root_nid = le16_to_cpu(dsb->root_nid);
314 sbi->inos = le64_to_cpu(dsb->inos);
315
316 sbi->build_time = le64_to_cpu(dsb->build_time);
317 sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec);
318
319 memcpy(&sb->s_uuid, dsb->uuid, sizeof(dsb->uuid));
320
321 ret = strscpy(sbi->volume_name, dsb->volume_name,
322 sizeof(dsb->volume_name));
323 if (ret < 0) { /* -E2BIG */
324 erofs_err(sb, "bad volume name without NIL terminator");
325 ret = -EFSCORRUPTED;
326 goto out;
327 }
328
329 /* parse on-disk compression configurations */
330 if (erofs_sb_has_compr_cfgs(sbi))
331 ret = erofs_load_compr_cfgs(sb, dsb);
332 else
333 ret = z_erofs_load_lz4_config(sb, dsb, NULL, 0);
334 out:
335 kunmap(page);
336 put_page(page);
337 return ret;
338 }
339
340 /* set up default EROFS parameters */
erofs_default_options(struct erofs_fs_context * ctx)341 static void erofs_default_options(struct erofs_fs_context *ctx)
342 {
343 #ifdef CONFIG_EROFS_FS_ZIP
344 ctx->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
345 ctx->max_sync_decompress_pages = 3;
346 ctx->readahead_sync_decompress = false;
347 #endif
348 #ifdef CONFIG_EROFS_FS_XATTR
349 set_opt(ctx, XATTR_USER);
350 #endif
351 #ifdef CONFIG_EROFS_FS_POSIX_ACL
352 set_opt(ctx, POSIX_ACL);
353 #endif
354 }
355
356 enum {
357 Opt_user_xattr,
358 Opt_acl,
359 Opt_cache_strategy,
360 Opt_dax,
361 Opt_dax_enum,
362 Opt_err
363 };
364
365 static const struct constant_table erofs_param_cache_strategy[] = {
366 {"disabled", EROFS_ZIP_CACHE_DISABLED},
367 {"readahead", EROFS_ZIP_CACHE_READAHEAD},
368 {"readaround", EROFS_ZIP_CACHE_READAROUND},
369 {}
370 };
371
372 static const struct constant_table erofs_dax_param_enums[] = {
373 {"always", EROFS_MOUNT_DAX_ALWAYS},
374 {"never", EROFS_MOUNT_DAX_NEVER},
375 {}
376 };
377
378 static const struct fs_parameter_spec erofs_fs_parameters[] = {
379 fsparam_flag_no("user_xattr", Opt_user_xattr),
380 fsparam_flag_no("acl", Opt_acl),
381 fsparam_enum("cache_strategy", Opt_cache_strategy,
382 erofs_param_cache_strategy),
383 fsparam_flag("dax", Opt_dax),
384 fsparam_enum("dax", Opt_dax_enum, erofs_dax_param_enums),
385 {}
386 };
387
erofs_fc_set_dax_mode(struct fs_context * fc,unsigned int mode)388 static bool erofs_fc_set_dax_mode(struct fs_context *fc, unsigned int mode)
389 {
390 #ifdef CONFIG_FS_DAX
391 struct erofs_fs_context *ctx = fc->fs_private;
392
393 switch (mode) {
394 case EROFS_MOUNT_DAX_ALWAYS:
395 warnfc(fc, "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
396 set_opt(ctx, DAX_ALWAYS);
397 clear_opt(ctx, DAX_NEVER);
398 return true;
399 case EROFS_MOUNT_DAX_NEVER:
400 set_opt(ctx, DAX_NEVER);
401 clear_opt(ctx, DAX_ALWAYS);
402 return true;
403 default:
404 DBG_BUGON(1);
405 return false;
406 }
407 #else
408 errorfc(fc, "dax options not supported");
409 return false;
410 #endif
411 }
412
erofs_fc_parse_param(struct fs_context * fc,struct fs_parameter * param)413 static int erofs_fc_parse_param(struct fs_context *fc,
414 struct fs_parameter *param)
415 {
416 struct erofs_fs_context *ctx __maybe_unused = fc->fs_private;
417 struct fs_parse_result result;
418 int opt;
419
420 opt = fs_parse(fc, erofs_fs_parameters, param, &result);
421 if (opt < 0)
422 return opt;
423
424 switch (opt) {
425 case Opt_user_xattr:
426 #ifdef CONFIG_EROFS_FS_XATTR
427 if (result.boolean)
428 set_opt(ctx, XATTR_USER);
429 else
430 clear_opt(ctx, XATTR_USER);
431 #else
432 errorfc(fc, "{,no}user_xattr options not supported");
433 #endif
434 break;
435 case Opt_acl:
436 #ifdef CONFIG_EROFS_FS_POSIX_ACL
437 if (result.boolean)
438 set_opt(ctx, POSIX_ACL);
439 else
440 clear_opt(ctx, POSIX_ACL);
441 #else
442 errorfc(fc, "{,no}acl options not supported");
443 #endif
444 break;
445 case Opt_cache_strategy:
446 #ifdef CONFIG_EROFS_FS_ZIP
447 ctx->cache_strategy = result.uint_32;
448 #else
449 errorfc(fc, "compression not supported, cache_strategy ignored");
450 #endif
451 break;
452 case Opt_dax:
453 if (!erofs_fc_set_dax_mode(fc, EROFS_MOUNT_DAX_ALWAYS))
454 return -EINVAL;
455 break;
456 case Opt_dax_enum:
457 if (!erofs_fc_set_dax_mode(fc, result.uint_32))
458 return -EINVAL;
459 break;
460 default:
461 return -ENOPARAM;
462 }
463 return 0;
464 }
465
466 #ifdef CONFIG_EROFS_FS_ZIP
467 static const struct address_space_operations managed_cache_aops;
468
erofs_managed_cache_releasepage(struct page * page,gfp_t gfp_mask)469 static int erofs_managed_cache_releasepage(struct page *page, gfp_t gfp_mask)
470 {
471 int ret = 1; /* 0 - busy */
472 struct address_space *const mapping = page->mapping;
473
474 DBG_BUGON(!PageLocked(page));
475 DBG_BUGON(mapping->a_ops != &managed_cache_aops);
476
477 if (PagePrivate(page))
478 ret = erofs_try_to_free_cached_page(mapping, page);
479
480 return ret;
481 }
482
erofs_managed_cache_invalidatepage(struct page * page,unsigned int offset,unsigned int length)483 static void erofs_managed_cache_invalidatepage(struct page *page,
484 unsigned int offset,
485 unsigned int length)
486 {
487 const unsigned int stop = length + offset;
488
489 DBG_BUGON(!PageLocked(page));
490
491 /* Check for potential overflow in debug mode */
492 DBG_BUGON(stop > PAGE_SIZE || stop < length);
493
494 if (offset == 0 && stop == PAGE_SIZE)
495 while (!erofs_managed_cache_releasepage(page, GFP_NOFS))
496 cond_resched();
497 }
498
499 static const struct address_space_operations managed_cache_aops = {
500 .releasepage = erofs_managed_cache_releasepage,
501 .invalidatepage = erofs_managed_cache_invalidatepage,
502 };
503
erofs_init_managed_cache(struct super_block * sb)504 static int erofs_init_managed_cache(struct super_block *sb)
505 {
506 struct erofs_sb_info *const sbi = EROFS_SB(sb);
507 struct inode *const inode = new_inode(sb);
508
509 if (!inode)
510 return -ENOMEM;
511
512 set_nlink(inode, 1);
513 inode->i_size = OFFSET_MAX;
514
515 inode->i_mapping->a_ops = &managed_cache_aops;
516 mapping_set_gfp_mask(inode->i_mapping,
517 GFP_NOFS | __GFP_HIGHMEM | __GFP_MOVABLE);
518 sbi->managed_cache = inode;
519 return 0;
520 }
521 #else
erofs_init_managed_cache(struct super_block * sb)522 static int erofs_init_managed_cache(struct super_block *sb) { return 0; }
523 #endif
524
erofs_fc_fill_super(struct super_block * sb,struct fs_context * fc)525 static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
526 {
527 struct inode *inode;
528 struct erofs_sb_info *sbi;
529 struct erofs_fs_context *ctx = fc->fs_private;
530 int err;
531
532 sb->s_magic = EROFS_SUPER_MAGIC;
533
534 if (!sb_set_blocksize(sb, EROFS_BLKSIZ)) {
535 erofs_err(sb, "failed to set erofs blksize");
536 return -EINVAL;
537 }
538
539 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
540 if (!sbi)
541 return -ENOMEM;
542
543 sb->s_fs_info = sbi;
544 sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
545 err = erofs_read_superblock(sb);
546 if (err)
547 return err;
548
549 if (test_opt(ctx, DAX_ALWAYS) &&
550 !bdev_dax_supported(sb->s_bdev, EROFS_BLKSIZ)) {
551 errorfc(fc, "DAX unsupported by block device. Turning off DAX.");
552 clear_opt(ctx, DAX_ALWAYS);
553 }
554 sb->s_flags |= SB_RDONLY | SB_NOATIME;
555 sb->s_maxbytes = MAX_LFS_FILESIZE;
556 sb->s_time_gran = 1;
557
558 sb->s_op = &erofs_sops;
559 sb->s_xattr = erofs_xattr_handlers;
560
561 if (test_opt(ctx, POSIX_ACL))
562 sb->s_flags |= SB_POSIXACL;
563 else
564 sb->s_flags &= ~SB_POSIXACL;
565
566 sbi->ctx = *ctx;
567
568 #ifdef CONFIG_EROFS_FS_ZIP
569 xa_init(&sbi->managed_pslots);
570 #endif
571
572 /* get the root inode */
573 inode = erofs_iget(sb, ROOT_NID(sbi), true);
574 if (IS_ERR(inode))
575 return PTR_ERR(inode);
576
577 if (!S_ISDIR(inode->i_mode)) {
578 erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)",
579 ROOT_NID(sbi), inode->i_mode);
580 iput(inode);
581 return -EINVAL;
582 }
583
584 sb->s_root = d_make_root(inode);
585 if (!sb->s_root)
586 return -ENOMEM;
587
588 erofs_shrinker_register(sb);
589 /* sb->s_umount is already locked, SB_ACTIVE and SB_BORN are not set */
590 err = erofs_init_managed_cache(sb);
591 if (err)
592 return err;
593
594 erofs_info(sb, "mounted with root inode @ nid %llu.", ROOT_NID(sbi));
595 return 0;
596 }
597
erofs_fc_get_tree(struct fs_context * fc)598 static int erofs_fc_get_tree(struct fs_context *fc)
599 {
600 return get_tree_bdev(fc, erofs_fc_fill_super);
601 }
602
erofs_fc_reconfigure(struct fs_context * fc)603 static int erofs_fc_reconfigure(struct fs_context *fc)
604 {
605 struct super_block *sb = fc->root->d_sb;
606 struct erofs_sb_info *sbi = EROFS_SB(sb);
607 struct erofs_fs_context *ctx = fc->fs_private;
608
609 DBG_BUGON(!sb_rdonly(sb));
610
611 if (test_opt(ctx, POSIX_ACL))
612 fc->sb_flags |= SB_POSIXACL;
613 else
614 fc->sb_flags &= ~SB_POSIXACL;
615
616 sbi->ctx = *ctx;
617
618 fc->sb_flags |= SB_RDONLY;
619 return 0;
620 }
621
erofs_fc_free(struct fs_context * fc)622 static void erofs_fc_free(struct fs_context *fc)
623 {
624 kfree(fc->fs_private);
625 }
626
627 static const struct fs_context_operations erofs_context_ops = {
628 .parse_param = erofs_fc_parse_param,
629 .get_tree = erofs_fc_get_tree,
630 .reconfigure = erofs_fc_reconfigure,
631 .free = erofs_fc_free,
632 };
633
erofs_init_fs_context(struct fs_context * fc)634 static int erofs_init_fs_context(struct fs_context *fc)
635 {
636 fc->fs_private = kzalloc(sizeof(struct erofs_fs_context), GFP_KERNEL);
637 if (!fc->fs_private)
638 return -ENOMEM;
639
640 /* set default mount options */
641 erofs_default_options(fc->fs_private);
642
643 fc->ops = &erofs_context_ops;
644
645 return 0;
646 }
647
648 /*
649 * could be triggered after deactivate_locked_super()
650 * is called, thus including umount and failed to initialize.
651 */
erofs_kill_sb(struct super_block * sb)652 static void erofs_kill_sb(struct super_block *sb)
653 {
654 struct erofs_sb_info *sbi;
655
656 WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
657
658 kill_block_super(sb);
659
660 sbi = EROFS_SB(sb);
661 if (!sbi)
662 return;
663 fs_put_dax(sbi->dax_dev);
664 kfree(sbi);
665 sb->s_fs_info = NULL;
666 }
667
668 /* called when ->s_root is non-NULL */
erofs_put_super(struct super_block * sb)669 static void erofs_put_super(struct super_block *sb)
670 {
671 struct erofs_sb_info *const sbi = EROFS_SB(sb);
672
673 DBG_BUGON(!sbi);
674
675 erofs_shrinker_unregister(sb);
676 #ifdef CONFIG_EROFS_FS_ZIP
677 iput(sbi->managed_cache);
678 sbi->managed_cache = NULL;
679 #endif
680 }
681
682 static struct file_system_type erofs_fs_type = {
683 .owner = THIS_MODULE,
684 .name = "erofs",
685 .init_fs_context = erofs_init_fs_context,
686 .kill_sb = erofs_kill_sb,
687 .fs_flags = FS_REQUIRES_DEV,
688 };
689 MODULE_ALIAS_FS("erofs");
690
erofs_module_init(void)691 static int __init erofs_module_init(void)
692 {
693 int err;
694
695 erofs_check_ondisk_layout_definitions();
696
697 erofs_inode_cachep = kmem_cache_create("erofs_inode",
698 sizeof(struct erofs_inode), 0,
699 SLAB_RECLAIM_ACCOUNT,
700 erofs_inode_init_once);
701 if (!erofs_inode_cachep) {
702 err = -ENOMEM;
703 goto icache_err;
704 }
705
706 err = erofs_init_shrinker();
707 if (err)
708 goto shrinker_err;
709
710 erofs_pcpubuf_init();
711 err = z_erofs_init_zip_subsystem();
712 if (err)
713 goto zip_err;
714
715 err = register_filesystem(&erofs_fs_type);
716 if (err)
717 goto fs_err;
718
719 return 0;
720
721 fs_err:
722 z_erofs_exit_zip_subsystem();
723 zip_err:
724 erofs_exit_shrinker();
725 shrinker_err:
726 kmem_cache_destroy(erofs_inode_cachep);
727 icache_err:
728 return err;
729 }
730
erofs_module_exit(void)731 static void __exit erofs_module_exit(void)
732 {
733 unregister_filesystem(&erofs_fs_type);
734 z_erofs_exit_zip_subsystem();
735 erofs_exit_shrinker();
736
737 /* Ensure all RCU free inodes are safe before cache is destroyed. */
738 rcu_barrier();
739 kmem_cache_destroy(erofs_inode_cachep);
740 erofs_pcpubuf_exit();
741 }
742
743 /* get filesystem statistics */
erofs_statfs(struct dentry * dentry,struct kstatfs * buf)744 static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
745 {
746 struct super_block *sb = dentry->d_sb;
747 struct erofs_sb_info *sbi = EROFS_SB(sb);
748 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
749
750 buf->f_type = sb->s_magic;
751 buf->f_bsize = EROFS_BLKSIZ;
752 buf->f_blocks = sbi->blocks;
753 buf->f_bfree = buf->f_bavail = 0;
754
755 buf->f_files = ULLONG_MAX;
756 buf->f_ffree = ULLONG_MAX - sbi->inos;
757
758 buf->f_namelen = EROFS_NAME_LEN;
759
760 buf->f_fsid = u64_to_fsid(id);
761 return 0;
762 }
763
erofs_show_options(struct seq_file * seq,struct dentry * root)764 static int erofs_show_options(struct seq_file *seq, struct dentry *root)
765 {
766 struct erofs_sb_info *sbi = EROFS_SB(root->d_sb);
767 struct erofs_fs_context *ctx = &sbi->ctx;
768
769 #ifdef CONFIG_EROFS_FS_XATTR
770 if (test_opt(ctx, XATTR_USER))
771 seq_puts(seq, ",user_xattr");
772 else
773 seq_puts(seq, ",nouser_xattr");
774 #endif
775 #ifdef CONFIG_EROFS_FS_POSIX_ACL
776 if (test_opt(ctx, POSIX_ACL))
777 seq_puts(seq, ",acl");
778 else
779 seq_puts(seq, ",noacl");
780 #endif
781 #ifdef CONFIG_EROFS_FS_ZIP
782 if (ctx->cache_strategy == EROFS_ZIP_CACHE_DISABLED)
783 seq_puts(seq, ",cache_strategy=disabled");
784 else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAHEAD)
785 seq_puts(seq, ",cache_strategy=readahead");
786 else if (ctx->cache_strategy == EROFS_ZIP_CACHE_READAROUND)
787 seq_puts(seq, ",cache_strategy=readaround");
788 #endif
789 if (test_opt(ctx, DAX_ALWAYS))
790 seq_puts(seq, ",dax=always");
791 if (test_opt(ctx, DAX_NEVER))
792 seq_puts(seq, ",dax=never");
793 return 0;
794 }
795
796 const struct super_operations erofs_sops = {
797 .put_super = erofs_put_super,
798 .alloc_inode = erofs_alloc_inode,
799 .free_inode = erofs_free_inode,
800 .statfs = erofs_statfs,
801 .show_options = erofs_show_options,
802 };
803
804 module_init(erofs_module_init);
805 module_exit(erofs_module_exit);
806
807 MODULE_DESCRIPTION("Enhanced ROM File System");
808 MODULE_AUTHOR("Gao Xiang, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc.");
809 MODULE_LICENSE("GPL");
810 MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
811
812