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[thirdparty/linux.git] / fs / erofs / super.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2017-2018 HUAWEI, Inc.
4 * https://www.huawei.com/
5 * Copyright (C) 2021, Alibaba Cloud
6 */
7 #include <linux/statfs.h>
8 #include <linux/seq_file.h>
9 #include <linux/crc32c.h>
10 #include <linux/fs_context.h>
11 #include <linux/fs_parser.h>
12 #include <linux/exportfs.h>
13 #include "xattr.h"
14
15 #define CREATE_TRACE_POINTS
16 #include <trace/events/erofs.h>
17
18 static struct kmem_cache *erofs_inode_cachep __read_mostly;
19
20 void _erofs_err(struct super_block *sb, const char *func, const char *fmt, ...)
21 {
22 struct va_format vaf;
23 va_list args;
24
25 va_start(args, fmt);
26
27 vaf.fmt = fmt;
28 vaf.va = &args;
29
30 if (sb)
31 pr_err("(device %s): %s: %pV", sb->s_id, func, &vaf);
32 else
33 pr_err("%s: %pV", func, &vaf);
34 va_end(args);
35 }
36
37 void _erofs_info(struct super_block *sb, const char *func, const char *fmt, ...)
38 {
39 struct va_format vaf;
40 va_list args;
41
42 va_start(args, fmt);
43
44 vaf.fmt = fmt;
45 vaf.va = &args;
46
47 if (sb)
48 pr_info("(device %s): %pV", sb->s_id, &vaf);
49 else
50 pr_info("%pV", &vaf);
51 va_end(args);
52 }
53
54 static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata)
55 {
56 size_t len = 1 << EROFS_SB(sb)->blkszbits;
57 struct erofs_super_block *dsb;
58 u32 expected_crc, crc;
59
60 if (len > EROFS_SUPER_OFFSET)
61 len -= EROFS_SUPER_OFFSET;
62
63 dsb = kmemdup(sbdata + EROFS_SUPER_OFFSET, len, GFP_KERNEL);
64 if (!dsb)
65 return -ENOMEM;
66
67 expected_crc = le32_to_cpu(dsb->checksum);
68 dsb->checksum = 0;
69 /* to allow for x86 boot sectors and other oddities. */
70 crc = crc32c(~0, dsb, len);
71 kfree(dsb);
72
73 if (crc != expected_crc) {
74 erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected",
75 crc, expected_crc);
76 return -EBADMSG;
77 }
78 return 0;
79 }
80
81 static void erofs_inode_init_once(void *ptr)
82 {
83 struct erofs_inode *vi = ptr;
84
85 inode_init_once(&vi->vfs_inode);
86 }
87
88 static struct inode *erofs_alloc_inode(struct super_block *sb)
89 {
90 struct erofs_inode *vi =
91 alloc_inode_sb(sb, erofs_inode_cachep, GFP_KERNEL);
92
93 if (!vi)
94 return NULL;
95
96 /* zero out everything except vfs_inode */
97 memset(vi, 0, offsetof(struct erofs_inode, vfs_inode));
98 return &vi->vfs_inode;
99 }
100
101 static void erofs_free_inode(struct inode *inode)
102 {
103 struct erofs_inode *vi = EROFS_I(inode);
104
105 if (inode->i_op == &erofs_fast_symlink_iops)
106 kfree(inode->i_link);
107 kfree(vi->xattr_shared_xattrs);
108 kmem_cache_free(erofs_inode_cachep, vi);
109 }
110
111 static bool check_layout_compatibility(struct super_block *sb,
112 struct erofs_super_block *dsb)
113 {
114 const unsigned int feature = le32_to_cpu(dsb->feature_incompat);
115
116 EROFS_SB(sb)->feature_incompat = feature;
117
118 /* check if current kernel meets all mandatory requirements */
119 if (feature & (~EROFS_ALL_FEATURE_INCOMPAT)) {
120 erofs_err(sb, "unidentified incompatible feature %x, please upgrade kernel",
121 feature & ~EROFS_ALL_FEATURE_INCOMPAT);
122 return false;
123 }
124 return true;
125 }
126
127 /* read variable-sized metadata, offset will be aligned by 4-byte */
128 void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,
129 erofs_off_t *offset, int *lengthp)
130 {
131 u8 *buffer, *ptr;
132 int len, i, cnt;
133
134 *offset = round_up(*offset, 4);
135 ptr = erofs_bread(buf, erofs_blknr(sb, *offset), EROFS_KMAP);
136 if (IS_ERR(ptr))
137 return ptr;
138
139 len = le16_to_cpu(*(__le16 *)&ptr[erofs_blkoff(sb, *offset)]);
140 if (!len)
141 len = U16_MAX + 1;
142 buffer = kmalloc(len, GFP_KERNEL);
143 if (!buffer)
144 return ERR_PTR(-ENOMEM);
145 *offset += sizeof(__le16);
146 *lengthp = len;
147
148 for (i = 0; i < len; i += cnt) {
149 cnt = min_t(int, sb->s_blocksize - erofs_blkoff(sb, *offset),
150 len - i);
151 ptr = erofs_bread(buf, erofs_blknr(sb, *offset), EROFS_KMAP);
152 if (IS_ERR(ptr)) {
153 kfree(buffer);
154 return ptr;
155 }
156 memcpy(buffer + i, ptr + erofs_blkoff(sb, *offset), cnt);
157 *offset += cnt;
158 }
159 return buffer;
160 }
161
162 #ifndef CONFIG_EROFS_FS_ZIP
163 static int z_erofs_parse_cfgs(struct super_block *sb,
164 struct erofs_super_block *dsb)
165 {
166 if (!dsb->u1.available_compr_algs)
167 return 0;
168
169 erofs_err(sb, "compression disabled, unable to mount compressed EROFS");
170 return -EOPNOTSUPP;
171 }
172 #endif
173
174 static int erofs_init_device(struct erofs_buf *buf, struct super_block *sb,
175 struct erofs_device_info *dif, erofs_off_t *pos)
176 {
177 struct erofs_sb_info *sbi = EROFS_SB(sb);
178 struct erofs_fscache *fscache;
179 struct erofs_deviceslot *dis;
180 struct file *bdev_file;
181 void *ptr;
182
183 ptr = erofs_read_metabuf(buf, sb, erofs_blknr(sb, *pos), EROFS_KMAP);
184 if (IS_ERR(ptr))
185 return PTR_ERR(ptr);
186 dis = ptr + erofs_blkoff(sb, *pos);
187
188 if (!sbi->devs->flatdev && !dif->path) {
189 if (!dis->tag[0]) {
190 erofs_err(sb, "empty device tag @ pos %llu", *pos);
191 return -EINVAL;
192 }
193 dif->path = kmemdup_nul(dis->tag, sizeof(dis->tag), GFP_KERNEL);
194 if (!dif->path)
195 return -ENOMEM;
196 }
197
198 if (erofs_is_fscache_mode(sb)) {
199 fscache = erofs_fscache_register_cookie(sb, dif->path, 0);
200 if (IS_ERR(fscache))
201 return PTR_ERR(fscache);
202 dif->fscache = fscache;
203 } else if (!sbi->devs->flatdev) {
204 bdev_file = bdev_file_open_by_path(dif->path, BLK_OPEN_READ,
205 sb->s_type, NULL);
206 if (IS_ERR(bdev_file))
207 return PTR_ERR(bdev_file);
208 dif->bdev_file = bdev_file;
209 dif->dax_dev = fs_dax_get_by_bdev(file_bdev(bdev_file),
210 &dif->dax_part_off, NULL, NULL);
211 }
212
213 dif->blocks = le32_to_cpu(dis->blocks);
214 dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr);
215 sbi->total_blocks += dif->blocks;
216 *pos += EROFS_DEVT_SLOT_SIZE;
217 return 0;
218 }
219
220 static int erofs_scan_devices(struct super_block *sb,
221 struct erofs_super_block *dsb)
222 {
223 struct erofs_sb_info *sbi = EROFS_SB(sb);
224 unsigned int ondisk_extradevs;
225 erofs_off_t pos;
226 struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
227 struct erofs_device_info *dif;
228 int id, err = 0;
229
230 sbi->total_blocks = sbi->primarydevice_blocks;
231 if (!erofs_sb_has_device_table(sbi))
232 ondisk_extradevs = 0;
233 else
234 ondisk_extradevs = le16_to_cpu(dsb->extra_devices);
235
236 if (sbi->devs->extra_devices &&
237 ondisk_extradevs != sbi->devs->extra_devices) {
238 erofs_err(sb, "extra devices don't match (ondisk %u, given %u)",
239 ondisk_extradevs, sbi->devs->extra_devices);
240 return -EINVAL;
241 }
242 if (!ondisk_extradevs)
243 return 0;
244
245 if (!sbi->devs->extra_devices && !erofs_is_fscache_mode(sb))
246 sbi->devs->flatdev = true;
247
248 sbi->device_id_mask = roundup_pow_of_two(ondisk_extradevs + 1) - 1;
249 pos = le16_to_cpu(dsb->devt_slotoff) * EROFS_DEVT_SLOT_SIZE;
250 down_read(&sbi->devs->rwsem);
251 if (sbi->devs->extra_devices) {
252 idr_for_each_entry(&sbi->devs->tree, dif, id) {
253 err = erofs_init_device(&buf, sb, dif, &pos);
254 if (err)
255 break;
256 }
257 } else {
258 for (id = 0; id < ondisk_extradevs; id++) {
259 dif = kzalloc(sizeof(*dif), GFP_KERNEL);
260 if (!dif) {
261 err = -ENOMEM;
262 break;
263 }
264
265 err = idr_alloc(&sbi->devs->tree, dif, 0, 0, GFP_KERNEL);
266 if (err < 0) {
267 kfree(dif);
268 break;
269 }
270 ++sbi->devs->extra_devices;
271
272 err = erofs_init_device(&buf, sb, dif, &pos);
273 if (err)
274 break;
275 }
276 }
277 up_read(&sbi->devs->rwsem);
278 erofs_put_metabuf(&buf);
279 return err;
280 }
281
282 static int erofs_read_superblock(struct super_block *sb)
283 {
284 struct erofs_sb_info *sbi;
285 struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
286 struct erofs_super_block *dsb;
287 void *data;
288 int ret;
289
290 data = erofs_read_metabuf(&buf, sb, 0, EROFS_KMAP);
291 if (IS_ERR(data)) {
292 erofs_err(sb, "cannot read erofs superblock");
293 return PTR_ERR(data);
294 }
295
296 sbi = EROFS_SB(sb);
297 dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET);
298
299 ret = -EINVAL;
300 if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) {
301 erofs_err(sb, "cannot find valid erofs superblock");
302 goto out;
303 }
304
305 sbi->blkszbits = dsb->blkszbits;
306 if (sbi->blkszbits < 9 || sbi->blkszbits > PAGE_SHIFT) {
307 erofs_err(sb, "blkszbits %u isn't supported", sbi->blkszbits);
308 goto out;
309 }
310 if (dsb->dirblkbits) {
311 erofs_err(sb, "dirblkbits %u isn't supported", dsb->dirblkbits);
312 goto out;
313 }
314
315 sbi->feature_compat = le32_to_cpu(dsb->feature_compat);
316 if (erofs_sb_has_sb_chksum(sbi)) {
317 ret = erofs_superblock_csum_verify(sb, data);
318 if (ret)
319 goto out;
320 }
321
322 ret = -EINVAL;
323 if (!check_layout_compatibility(sb, dsb))
324 goto out;
325
326 sbi->sb_size = 128 + dsb->sb_extslots * EROFS_SB_EXTSLOT_SIZE;
327 if (sbi->sb_size > PAGE_SIZE - EROFS_SUPER_OFFSET) {
328 erofs_err(sb, "invalid sb_extslots %u (more than a fs block)",
329 sbi->sb_size);
330 goto out;
331 }
332 sbi->primarydevice_blocks = le32_to_cpu(dsb->blocks);
333 sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr);
334 #ifdef CONFIG_EROFS_FS_XATTR
335 sbi->xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr);
336 sbi->xattr_prefix_start = le32_to_cpu(dsb->xattr_prefix_start);
337 sbi->xattr_prefix_count = dsb->xattr_prefix_count;
338 sbi->xattr_filter_reserved = dsb->xattr_filter_reserved;
339 #endif
340 sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact));
341 sbi->root_nid = le16_to_cpu(dsb->root_nid);
342 sbi->packed_nid = le64_to_cpu(dsb->packed_nid);
343 sbi->inos = le64_to_cpu(dsb->inos);
344
345 sbi->build_time = le64_to_cpu(dsb->build_time);
346 sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec);
347
348 memcpy(&sb->s_uuid, dsb->uuid, sizeof(dsb->uuid));
349
350 ret = strscpy(sbi->volume_name, dsb->volume_name,
351 sizeof(dsb->volume_name));
352 if (ret < 0) { /* -E2BIG */
353 erofs_err(sb, "bad volume name without NIL terminator");
354 ret = -EFSCORRUPTED;
355 goto out;
356 }
357
358 /* parse on-disk compression configurations */
359 ret = z_erofs_parse_cfgs(sb, dsb);
360 if (ret < 0)
361 goto out;
362
363 /* handle multiple devices */
364 ret = erofs_scan_devices(sb, dsb);
365
366 if (erofs_is_fscache_mode(sb))
367 erofs_info(sb, "EXPERIMENTAL fscache-based on-demand read feature in use. Use at your own risk!");
368 out:
369 erofs_put_metabuf(&buf);
370 return ret;
371 }
372
373 static void erofs_default_options(struct erofs_fs_context *ctx)
374 {
375 #ifdef CONFIG_EROFS_FS_ZIP
376 ctx->opt.cache_strategy = EROFS_ZIP_CACHE_READAROUND;
377 ctx->opt.max_sync_decompress_pages = 3;
378 ctx->opt.sync_decompress = EROFS_SYNC_DECOMPRESS_AUTO;
379 #endif
380 #ifdef CONFIG_EROFS_FS_XATTR
381 set_opt(&ctx->opt, XATTR_USER);
382 #endif
383 #ifdef CONFIG_EROFS_FS_POSIX_ACL
384 set_opt(&ctx->opt, POSIX_ACL);
385 #endif
386 }
387
388 enum {
389 Opt_user_xattr,
390 Opt_acl,
391 Opt_cache_strategy,
392 Opt_dax,
393 Opt_dax_enum,
394 Opt_device,
395 Opt_fsid,
396 Opt_domain_id,
397 Opt_err
398 };
399
400 static const struct constant_table erofs_param_cache_strategy[] = {
401 {"disabled", EROFS_ZIP_CACHE_DISABLED},
402 {"readahead", EROFS_ZIP_CACHE_READAHEAD},
403 {"readaround", EROFS_ZIP_CACHE_READAROUND},
404 {}
405 };
406
407 static const struct constant_table erofs_dax_param_enums[] = {
408 {"always", EROFS_MOUNT_DAX_ALWAYS},
409 {"never", EROFS_MOUNT_DAX_NEVER},
410 {}
411 };
412
413 static const struct fs_parameter_spec erofs_fs_parameters[] = {
414 fsparam_flag_no("user_xattr", Opt_user_xattr),
415 fsparam_flag_no("acl", Opt_acl),
416 fsparam_enum("cache_strategy", Opt_cache_strategy,
417 erofs_param_cache_strategy),
418 fsparam_flag("dax", Opt_dax),
419 fsparam_enum("dax", Opt_dax_enum, erofs_dax_param_enums),
420 fsparam_string("device", Opt_device),
421 fsparam_string("fsid", Opt_fsid),
422 fsparam_string("domain_id", Opt_domain_id),
423 {}
424 };
425
426 static bool erofs_fc_set_dax_mode(struct fs_context *fc, unsigned int mode)
427 {
428 #ifdef CONFIG_FS_DAX
429 struct erofs_fs_context *ctx = fc->fs_private;
430
431 switch (mode) {
432 case EROFS_MOUNT_DAX_ALWAYS:
433 warnfc(fc, "DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
434 set_opt(&ctx->opt, DAX_ALWAYS);
435 clear_opt(&ctx->opt, DAX_NEVER);
436 return true;
437 case EROFS_MOUNT_DAX_NEVER:
438 set_opt(&ctx->opt, DAX_NEVER);
439 clear_opt(&ctx->opt, DAX_ALWAYS);
440 return true;
441 default:
442 DBG_BUGON(1);
443 return false;
444 }
445 #else
446 errorfc(fc, "dax options not supported");
447 return false;
448 #endif
449 }
450
451 static int erofs_fc_parse_param(struct fs_context *fc,
452 struct fs_parameter *param)
453 {
454 struct erofs_fs_context *ctx = fc->fs_private;
455 struct fs_parse_result result;
456 struct erofs_device_info *dif;
457 int opt, ret;
458
459 opt = fs_parse(fc, erofs_fs_parameters, param, &result);
460 if (opt < 0)
461 return opt;
462
463 switch (opt) {
464 case Opt_user_xattr:
465 #ifdef CONFIG_EROFS_FS_XATTR
466 if (result.boolean)
467 set_opt(&ctx->opt, XATTR_USER);
468 else
469 clear_opt(&ctx->opt, XATTR_USER);
470 #else
471 errorfc(fc, "{,no}user_xattr options not supported");
472 #endif
473 break;
474 case Opt_acl:
475 #ifdef CONFIG_EROFS_FS_POSIX_ACL
476 if (result.boolean)
477 set_opt(&ctx->opt, POSIX_ACL);
478 else
479 clear_opt(&ctx->opt, POSIX_ACL);
480 #else
481 errorfc(fc, "{,no}acl options not supported");
482 #endif
483 break;
484 case Opt_cache_strategy:
485 #ifdef CONFIG_EROFS_FS_ZIP
486 ctx->opt.cache_strategy = result.uint_32;
487 #else
488 errorfc(fc, "compression not supported, cache_strategy ignored");
489 #endif
490 break;
491 case Opt_dax:
492 if (!erofs_fc_set_dax_mode(fc, EROFS_MOUNT_DAX_ALWAYS))
493 return -EINVAL;
494 break;
495 case Opt_dax_enum:
496 if (!erofs_fc_set_dax_mode(fc, result.uint_32))
497 return -EINVAL;
498 break;
499 case Opt_device:
500 dif = kzalloc(sizeof(*dif), GFP_KERNEL);
501 if (!dif)
502 return -ENOMEM;
503 dif->path = kstrdup(param->string, GFP_KERNEL);
504 if (!dif->path) {
505 kfree(dif);
506 return -ENOMEM;
507 }
508 down_write(&ctx->devs->rwsem);
509 ret = idr_alloc(&ctx->devs->tree, dif, 0, 0, GFP_KERNEL);
510 up_write(&ctx->devs->rwsem);
511 if (ret < 0) {
512 kfree(dif->path);
513 kfree(dif);
514 return ret;
515 }
516 ++ctx->devs->extra_devices;
517 break;
518 #ifdef CONFIG_EROFS_FS_ONDEMAND
519 case Opt_fsid:
520 kfree(ctx->fsid);
521 ctx->fsid = kstrdup(param->string, GFP_KERNEL);
522 if (!ctx->fsid)
523 return -ENOMEM;
524 break;
525 case Opt_domain_id:
526 kfree(ctx->domain_id);
527 ctx->domain_id = kstrdup(param->string, GFP_KERNEL);
528 if (!ctx->domain_id)
529 return -ENOMEM;
530 break;
531 #else
532 case Opt_fsid:
533 case Opt_domain_id:
534 errorfc(fc, "%s option not supported", erofs_fs_parameters[opt].name);
535 break;
536 #endif
537 default:
538 return -ENOPARAM;
539 }
540 return 0;
541 }
542
543 static struct inode *erofs_nfs_get_inode(struct super_block *sb,
544 u64 ino, u32 generation)
545 {
546 return erofs_iget(sb, ino);
547 }
548
549 static struct dentry *erofs_fh_to_dentry(struct super_block *sb,
550 struct fid *fid, int fh_len, int fh_type)
551 {
552 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
553 erofs_nfs_get_inode);
554 }
555
556 static struct dentry *erofs_fh_to_parent(struct super_block *sb,
557 struct fid *fid, int fh_len, int fh_type)
558 {
559 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
560 erofs_nfs_get_inode);
561 }
562
563 static struct dentry *erofs_get_parent(struct dentry *child)
564 {
565 erofs_nid_t nid;
566 unsigned int d_type;
567 int err;
568
569 err = erofs_namei(d_inode(child), &dotdot_name, &nid, &d_type);
570 if (err)
571 return ERR_PTR(err);
572 return d_obtain_alias(erofs_iget(child->d_sb, nid));
573 }
574
575 static const struct export_operations erofs_export_ops = {
576 .encode_fh = generic_encode_ino32_fh,
577 .fh_to_dentry = erofs_fh_to_dentry,
578 .fh_to_parent = erofs_fh_to_parent,
579 .get_parent = erofs_get_parent,
580 };
581
582 static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
583 {
584 struct inode *inode;
585 struct erofs_sb_info *sbi;
586 struct erofs_fs_context *ctx = fc->fs_private;
587 int err;
588
589 sb->s_magic = EROFS_SUPER_MAGIC;
590 sb->s_flags |= SB_RDONLY | SB_NOATIME;
591 sb->s_maxbytes = MAX_LFS_FILESIZE;
592 sb->s_op = &erofs_sops;
593
594 sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
595 if (!sbi)
596 return -ENOMEM;
597
598 sb->s_fs_info = sbi;
599 sbi->opt = ctx->opt;
600 sbi->devs = ctx->devs;
601 ctx->devs = NULL;
602 sbi->fsid = ctx->fsid;
603 ctx->fsid = NULL;
604 sbi->domain_id = ctx->domain_id;
605 ctx->domain_id = NULL;
606
607 sbi->blkszbits = PAGE_SHIFT;
608 if (erofs_is_fscache_mode(sb)) {
609 sb->s_blocksize = PAGE_SIZE;
610 sb->s_blocksize_bits = PAGE_SHIFT;
611
612 err = erofs_fscache_register_fs(sb);
613 if (err)
614 return err;
615
616 err = super_setup_bdi(sb);
617 if (err)
618 return err;
619 } else {
620 if (!sb_set_blocksize(sb, PAGE_SIZE)) {
621 errorfc(fc, "failed to set initial blksize");
622 return -EINVAL;
623 }
624
625 sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev,
626 &sbi->dax_part_off,
627 NULL, NULL);
628 }
629
630 err = erofs_read_superblock(sb);
631 if (err)
632 return err;
633
634 if (sb->s_blocksize_bits != sbi->blkszbits) {
635 if (erofs_is_fscache_mode(sb)) {
636 errorfc(fc, "unsupported blksize for fscache mode");
637 return -EINVAL;
638 }
639 if (!sb_set_blocksize(sb, 1 << sbi->blkszbits)) {
640 errorfc(fc, "failed to set erofs blksize");
641 return -EINVAL;
642 }
643 }
644
645 if (test_opt(&sbi->opt, DAX_ALWAYS)) {
646 if (!sbi->dax_dev) {
647 errorfc(fc, "DAX unsupported by block device. Turning off DAX.");
648 clear_opt(&sbi->opt, DAX_ALWAYS);
649 } else if (sbi->blkszbits != PAGE_SHIFT) {
650 errorfc(fc, "unsupported blocksize for DAX");
651 clear_opt(&sbi->opt, DAX_ALWAYS);
652 }
653 }
654
655 sb->s_time_gran = 1;
656 sb->s_xattr = erofs_xattr_handlers;
657 sb->s_export_op = &erofs_export_ops;
658
659 if (test_opt(&sbi->opt, POSIX_ACL))
660 sb->s_flags |= SB_POSIXACL;
661 else
662 sb->s_flags &= ~SB_POSIXACL;
663
664 #ifdef CONFIG_EROFS_FS_ZIP
665 xa_init(&sbi->managed_pslots);
666 #endif
667
668 inode = erofs_iget(sb, sbi->root_nid);
669 if (IS_ERR(inode))
670 return PTR_ERR(inode);
671
672 if (!S_ISDIR(inode->i_mode)) {
673 erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)",
674 sbi->root_nid, inode->i_mode);
675 iput(inode);
676 return -EINVAL;
677 }
678
679 sb->s_root = d_make_root(inode);
680 if (!sb->s_root)
681 return -ENOMEM;
682
683 erofs_shrinker_register(sb);
684 if (erofs_sb_has_fragments(sbi) && sbi->packed_nid) {
685 sbi->packed_inode = erofs_iget(sb, sbi->packed_nid);
686 if (IS_ERR(sbi->packed_inode)) {
687 err = PTR_ERR(sbi->packed_inode);
688 sbi->packed_inode = NULL;
689 return err;
690 }
691 }
692 err = erofs_init_managed_cache(sb);
693 if (err)
694 return err;
695
696 err = erofs_xattr_prefixes_init(sb);
697 if (err)
698 return err;
699
700 err = erofs_register_sysfs(sb);
701 if (err)
702 return err;
703
704 erofs_info(sb, "mounted with root inode @ nid %llu.", sbi->root_nid);
705 return 0;
706 }
707
708 static int erofs_fc_get_tree(struct fs_context *fc)
709 {
710 struct erofs_fs_context *ctx = fc->fs_private;
711
712 if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && ctx->fsid)
713 return get_tree_nodev(fc, erofs_fc_fill_super);
714
715 return get_tree_bdev(fc, erofs_fc_fill_super);
716 }
717
718 static int erofs_fc_reconfigure(struct fs_context *fc)
719 {
720 struct super_block *sb = fc->root->d_sb;
721 struct erofs_sb_info *sbi = EROFS_SB(sb);
722 struct erofs_fs_context *ctx = fc->fs_private;
723
724 DBG_BUGON(!sb_rdonly(sb));
725
726 if (ctx->fsid || ctx->domain_id)
727 erofs_info(sb, "ignoring reconfiguration for fsid|domain_id.");
728
729 if (test_opt(&ctx->opt, POSIX_ACL))
730 fc->sb_flags |= SB_POSIXACL;
731 else
732 fc->sb_flags &= ~SB_POSIXACL;
733
734 sbi->opt = ctx->opt;
735
736 fc->sb_flags |= SB_RDONLY;
737 return 0;
738 }
739
740 static int erofs_release_device_info(int id, void *ptr, void *data)
741 {
742 struct erofs_device_info *dif = ptr;
743
744 fs_put_dax(dif->dax_dev, NULL);
745 if (dif->bdev_file)
746 fput(dif->bdev_file);
747 erofs_fscache_unregister_cookie(dif->fscache);
748 dif->fscache = NULL;
749 kfree(dif->path);
750 kfree(dif);
751 return 0;
752 }
753
754 static void erofs_free_dev_context(struct erofs_dev_context *devs)
755 {
756 if (!devs)
757 return;
758 idr_for_each(&devs->tree, &erofs_release_device_info, NULL);
759 idr_destroy(&devs->tree);
760 kfree(devs);
761 }
762
763 static void erofs_fc_free(struct fs_context *fc)
764 {
765 struct erofs_fs_context *ctx = fc->fs_private;
766
767 erofs_free_dev_context(ctx->devs);
768 kfree(ctx->fsid);
769 kfree(ctx->domain_id);
770 kfree(ctx);
771 }
772
773 static const struct fs_context_operations erofs_context_ops = {
774 .parse_param = erofs_fc_parse_param,
775 .get_tree = erofs_fc_get_tree,
776 .reconfigure = erofs_fc_reconfigure,
777 .free = erofs_fc_free,
778 };
779
780 static int erofs_init_fs_context(struct fs_context *fc)
781 {
782 struct erofs_fs_context *ctx;
783
784 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
785 if (!ctx)
786 return -ENOMEM;
787 ctx->devs = kzalloc(sizeof(struct erofs_dev_context), GFP_KERNEL);
788 if (!ctx->devs) {
789 kfree(ctx);
790 return -ENOMEM;
791 }
792 fc->fs_private = ctx;
793
794 idr_init(&ctx->devs->tree);
795 init_rwsem(&ctx->devs->rwsem);
796 erofs_default_options(ctx);
797 fc->ops = &erofs_context_ops;
798 return 0;
799 }
800
801 static void erofs_kill_sb(struct super_block *sb)
802 {
803 struct erofs_sb_info *sbi;
804
805 if (erofs_is_fscache_mode(sb))
806 kill_anon_super(sb);
807 else
808 kill_block_super(sb);
809
810 sbi = EROFS_SB(sb);
811 if (!sbi)
812 return;
813
814 erofs_free_dev_context(sbi->devs);
815 fs_put_dax(sbi->dax_dev, NULL);
816 erofs_fscache_unregister_fs(sb);
817 kfree(sbi->fsid);
818 kfree(sbi->domain_id);
819 kfree(sbi);
820 sb->s_fs_info = NULL;
821 }
822
823 static void erofs_put_super(struct super_block *sb)
824 {
825 struct erofs_sb_info *const sbi = EROFS_SB(sb);
826
827 DBG_BUGON(!sbi);
828
829 erofs_unregister_sysfs(sb);
830 erofs_shrinker_unregister(sb);
831 erofs_xattr_prefixes_cleanup(sb);
832 #ifdef CONFIG_EROFS_FS_ZIP
833 iput(sbi->managed_cache);
834 sbi->managed_cache = NULL;
835 #endif
836 iput(sbi->packed_inode);
837 sbi->packed_inode = NULL;
838 erofs_free_dev_context(sbi->devs);
839 sbi->devs = NULL;
840 erofs_fscache_unregister_fs(sb);
841 }
842
843 static struct file_system_type erofs_fs_type = {
844 .owner = THIS_MODULE,
845 .name = "erofs",
846 .init_fs_context = erofs_init_fs_context,
847 .kill_sb = erofs_kill_sb,
848 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
849 };
850 MODULE_ALIAS_FS("erofs");
851
852 static int __init erofs_module_init(void)
853 {
854 int err;
855
856 erofs_check_ondisk_layout_definitions();
857
858 erofs_inode_cachep = kmem_cache_create("erofs_inode",
859 sizeof(struct erofs_inode), 0,
860 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
861 erofs_inode_init_once);
862 if (!erofs_inode_cachep)
863 return -ENOMEM;
864
865 err = erofs_init_shrinker();
866 if (err)
867 goto shrinker_err;
868
869 err = z_erofs_lzma_init();
870 if (err)
871 goto lzma_err;
872
873 err = z_erofs_deflate_init();
874 if (err)
875 goto deflate_err;
876
877 erofs_pcpubuf_init();
878 err = z_erofs_init_zip_subsystem();
879 if (err)
880 goto zip_err;
881
882 err = erofs_init_sysfs();
883 if (err)
884 goto sysfs_err;
885
886 err = register_filesystem(&erofs_fs_type);
887 if (err)
888 goto fs_err;
889
890 return 0;
891
892 fs_err:
893 erofs_exit_sysfs();
894 sysfs_err:
895 z_erofs_exit_zip_subsystem();
896 zip_err:
897 z_erofs_deflate_exit();
898 deflate_err:
899 z_erofs_lzma_exit();
900 lzma_err:
901 erofs_exit_shrinker();
902 shrinker_err:
903 kmem_cache_destroy(erofs_inode_cachep);
904 return err;
905 }
906
907 static void __exit erofs_module_exit(void)
908 {
909 unregister_filesystem(&erofs_fs_type);
910
911 /* Ensure all RCU free inodes / pclusters are safe to be destroyed. */
912 rcu_barrier();
913
914 erofs_exit_sysfs();
915 z_erofs_exit_zip_subsystem();
916 z_erofs_deflate_exit();
917 z_erofs_lzma_exit();
918 erofs_exit_shrinker();
919 kmem_cache_destroy(erofs_inode_cachep);
920 erofs_pcpubuf_exit();
921 }
922
923 static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
924 {
925 struct super_block *sb = dentry->d_sb;
926 struct erofs_sb_info *sbi = EROFS_SB(sb);
927 u64 id = 0;
928
929 if (!erofs_is_fscache_mode(sb))
930 id = huge_encode_dev(sb->s_bdev->bd_dev);
931
932 buf->f_type = sb->s_magic;
933 buf->f_bsize = sb->s_blocksize;
934 buf->f_blocks = sbi->total_blocks;
935 buf->f_bfree = buf->f_bavail = 0;
936
937 buf->f_files = ULLONG_MAX;
938 buf->f_ffree = ULLONG_MAX - sbi->inos;
939
940 buf->f_namelen = EROFS_NAME_LEN;
941
942 buf->f_fsid = u64_to_fsid(id);
943 return 0;
944 }
945
946 static int erofs_show_options(struct seq_file *seq, struct dentry *root)
947 {
948 struct erofs_sb_info *sbi = EROFS_SB(root->d_sb);
949 struct erofs_mount_opts *opt = &sbi->opt;
950
951 #ifdef CONFIG_EROFS_FS_XATTR
952 if (test_opt(opt, XATTR_USER))
953 seq_puts(seq, ",user_xattr");
954 else
955 seq_puts(seq, ",nouser_xattr");
956 #endif
957 #ifdef CONFIG_EROFS_FS_POSIX_ACL
958 if (test_opt(opt, POSIX_ACL))
959 seq_puts(seq, ",acl");
960 else
961 seq_puts(seq, ",noacl");
962 #endif
963 #ifdef CONFIG_EROFS_FS_ZIP
964 if (opt->cache_strategy == EROFS_ZIP_CACHE_DISABLED)
965 seq_puts(seq, ",cache_strategy=disabled");
966 else if (opt->cache_strategy == EROFS_ZIP_CACHE_READAHEAD)
967 seq_puts(seq, ",cache_strategy=readahead");
968 else if (opt->cache_strategy == EROFS_ZIP_CACHE_READAROUND)
969 seq_puts(seq, ",cache_strategy=readaround");
970 #endif
971 if (test_opt(opt, DAX_ALWAYS))
972 seq_puts(seq, ",dax=always");
973 if (test_opt(opt, DAX_NEVER))
974 seq_puts(seq, ",dax=never");
975 #ifdef CONFIG_EROFS_FS_ONDEMAND
976 if (sbi->fsid)
977 seq_printf(seq, ",fsid=%s", sbi->fsid);
978 if (sbi->domain_id)
979 seq_printf(seq, ",domain_id=%s", sbi->domain_id);
980 #endif
981 return 0;
982 }
983
984 const struct super_operations erofs_sops = {
985 .put_super = erofs_put_super,
986 .alloc_inode = erofs_alloc_inode,
987 .free_inode = erofs_free_inode,
988 .statfs = erofs_statfs,
989 .show_options = erofs_show_options,
990 };
991
992 module_init(erofs_module_init);
993 module_exit(erofs_module_exit);
994
995 MODULE_DESCRIPTION("Enhanced ROM File System");
996 MODULE_AUTHOR("Gao Xiang, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc.");
997 MODULE_LICENSE("GPL");
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