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