xref: /openbmc/linux/fs/erofs/internal.h (revision f59a3ee6)
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 #ifndef __EROFS_INTERNAL_H
8 #define __EROFS_INTERNAL_H
9 
10 #include <linux/fs.h>
11 #include <linux/dcache.h>
12 #include <linux/mm.h>
13 #include <linux/pagemap.h>
14 #include <linux/bio.h>
15 #include <linux/buffer_head.h>
16 #include <linux/magic.h>
17 #include <linux/slab.h>
18 #include <linux/vmalloc.h>
19 #include <linux/iomap.h>
20 #include "erofs_fs.h"
21 
22 /* redefine pr_fmt "erofs: " */
23 #undef pr_fmt
24 #define pr_fmt(fmt) "erofs: " fmt
25 
26 __printf(3, 4) void _erofs_err(struct super_block *sb,
27 			       const char *function, const char *fmt, ...);
28 #define erofs_err(sb, fmt, ...)	\
29 	_erofs_err(sb, __func__, fmt "\n", ##__VA_ARGS__)
30 __printf(3, 4) void _erofs_info(struct super_block *sb,
31 			       const char *function, const char *fmt, ...);
32 #define erofs_info(sb, fmt, ...) \
33 	_erofs_info(sb, __func__, fmt "\n", ##__VA_ARGS__)
34 #ifdef CONFIG_EROFS_FS_DEBUG
35 #define erofs_dbg(x, ...)       pr_debug(x "\n", ##__VA_ARGS__)
36 #define DBG_BUGON               BUG_ON
37 #else
38 #define erofs_dbg(x, ...)       ((void)0)
39 #define DBG_BUGON(x)            ((void)(x))
40 #endif	/* !CONFIG_EROFS_FS_DEBUG */
41 
42 /* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
43 #define EROFS_SUPER_MAGIC   EROFS_SUPER_MAGIC_V1
44 
45 typedef u64 erofs_nid_t;
46 typedef u64 erofs_off_t;
47 /* data type for filesystem-wide blocks number */
48 typedef u32 erofs_blk_t;
49 
50 struct erofs_device_info {
51 	char *path;
52 	struct erofs_fscache *fscache;
53 	struct block_device *bdev;
54 	struct dax_device *dax_dev;
55 	u64 dax_part_off;
56 
57 	u32 blocks;
58 	u32 mapped_blkaddr;
59 };
60 
61 enum {
62 	EROFS_SYNC_DECOMPRESS_AUTO,
63 	EROFS_SYNC_DECOMPRESS_FORCE_ON,
64 	EROFS_SYNC_DECOMPRESS_FORCE_OFF
65 };
66 
67 struct erofs_mount_opts {
68 #ifdef CONFIG_EROFS_FS_ZIP
69 	/* current strategy of how to use managed cache */
70 	unsigned char cache_strategy;
71 	/* strategy of sync decompression (0 - auto, 1 - force on, 2 - force off) */
72 	unsigned int sync_decompress;
73 
74 	/* threshold for decompression synchronously */
75 	unsigned int max_sync_decompress_pages;
76 #endif
77 	unsigned int mount_opt;
78 	char *fsid;
79 	char *domain_id;
80 };
81 
82 struct erofs_dev_context {
83 	struct idr tree;
84 	struct rw_semaphore rwsem;
85 
86 	unsigned int extra_devices;
87 };
88 
89 struct erofs_fs_context {
90 	struct erofs_mount_opts opt;
91 	struct erofs_dev_context *devs;
92 };
93 
94 /* all filesystem-wide lz4 configurations */
95 struct erofs_sb_lz4_info {
96 	/* # of pages needed for EROFS lz4 rolling decompression */
97 	u16 max_distance_pages;
98 	/* maximum possible blocks for pclusters in the filesystem */
99 	u16 max_pclusterblks;
100 };
101 
102 struct erofs_domain {
103 	refcount_t ref;
104 	struct list_head list;
105 	struct fscache_volume *volume;
106 	char *domain_id;
107 };
108 
109 struct erofs_fscache {
110 	struct fscache_cookie *cookie;
111 	struct inode *inode;
112 	struct inode *anon_inode;
113 	struct erofs_domain *domain;
114 	char *name;
115 };
116 
117 struct erofs_sb_info {
118 	struct erofs_mount_opts opt;	/* options */
119 #ifdef CONFIG_EROFS_FS_ZIP
120 	/* list for all registered superblocks, mainly for shrinker */
121 	struct list_head list;
122 	struct mutex umount_mutex;
123 
124 	/* managed XArray arranged in physical block number */
125 	struct xarray managed_pslots;
126 
127 	unsigned int shrinker_run_no;
128 	u16 available_compr_algs;
129 
130 	/* pseudo inode to manage cached pages */
131 	struct inode *managed_cache;
132 
133 	struct erofs_sb_lz4_info lz4;
134 	struct inode *packed_inode;
135 #endif	/* CONFIG_EROFS_FS_ZIP */
136 	struct erofs_dev_context *devs;
137 	struct dax_device *dax_dev;
138 	u64 dax_part_off;
139 	u64 total_blocks;
140 	u32 primarydevice_blocks;
141 
142 	u32 meta_blkaddr;
143 #ifdef CONFIG_EROFS_FS_XATTR
144 	u32 xattr_blkaddr;
145 #endif
146 	u16 device_id_mask;	/* valid bits of device id to be used */
147 
148 	/* inode slot unit size in bit shift */
149 	unsigned char islotbits;
150 
151 	u32 sb_size;			/* total superblock size */
152 	u32 build_time_nsec;
153 	u64 build_time;
154 
155 	/* what we really care is nid, rather than ino.. */
156 	erofs_nid_t root_nid;
157 	/* used for statfs, f_files - f_favail */
158 	u64 inos;
159 
160 	u8 uuid[16];                    /* 128-bit uuid for volume */
161 	u8 volume_name[16];             /* volume name */
162 	u32 feature_compat;
163 	u32 feature_incompat;
164 
165 	/* sysfs support */
166 	struct kobject s_kobj;		/* /sys/fs/erofs/<devname> */
167 	struct completion s_kobj_unregister;
168 
169 	/* fscache support */
170 	struct fscache_volume *volume;
171 	struct erofs_fscache *s_fscache;
172 	struct erofs_domain *domain;
173 };
174 
175 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
176 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
177 
178 /* Mount flags set via mount options or defaults */
179 #define EROFS_MOUNT_XATTR_USER		0x00000010
180 #define EROFS_MOUNT_POSIX_ACL		0x00000020
181 #define EROFS_MOUNT_DAX_ALWAYS		0x00000040
182 #define EROFS_MOUNT_DAX_NEVER		0x00000080
183 
184 #define clear_opt(opt, option)	((opt)->mount_opt &= ~EROFS_MOUNT_##option)
185 #define set_opt(opt, option)	((opt)->mount_opt |= EROFS_MOUNT_##option)
186 #define test_opt(opt, option)	((opt)->mount_opt & EROFS_MOUNT_##option)
187 
188 static inline bool erofs_is_fscache_mode(struct super_block *sb)
189 {
190 	return IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && !sb->s_bdev;
191 }
192 
193 enum {
194 	EROFS_ZIP_CACHE_DISABLED,
195 	EROFS_ZIP_CACHE_READAHEAD,
196 	EROFS_ZIP_CACHE_READAROUND
197 };
198 
199 #define EROFS_LOCKED_MAGIC     (INT_MIN | 0xE0F510CCL)
200 
201 /* basic unit of the workstation of a super_block */
202 struct erofs_workgroup {
203 	/* the workgroup index in the workstation */
204 	pgoff_t index;
205 
206 	/* overall workgroup reference count */
207 	atomic_t refcount;
208 };
209 
210 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
211 						 int val)
212 {
213 	preempt_disable();
214 	if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
215 		preempt_enable();
216 		return false;
217 	}
218 	return true;
219 }
220 
221 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
222 					    int orig_val)
223 {
224 	/*
225 	 * other observers should notice all modifications
226 	 * in the freezing period.
227 	 */
228 	smp_mb();
229 	atomic_set(&grp->refcount, orig_val);
230 	preempt_enable();
231 }
232 
233 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
234 {
235 	return atomic_cond_read_relaxed(&grp->refcount,
236 					VAL != EROFS_LOCKED_MAGIC);
237 }
238 
239 /* we strictly follow PAGE_SIZE and no buffer head yet */
240 #define LOG_BLOCK_SIZE		PAGE_SHIFT
241 
242 #undef LOG_SECTORS_PER_BLOCK
243 #define LOG_SECTORS_PER_BLOCK	(PAGE_SHIFT - 9)
244 
245 #undef SECTORS_PER_BLOCK
246 #define SECTORS_PER_BLOCK	(1 << SECTORS_PER_BLOCK)
247 
248 #define EROFS_BLKSIZ		(1 << LOG_BLOCK_SIZE)
249 
250 #if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
251 #error erofs cannot be used in this platform
252 #endif
253 
254 enum erofs_kmap_type {
255 	EROFS_NO_KMAP,		/* don't map the buffer */
256 	EROFS_KMAP,		/* use kmap() to map the buffer */
257 	EROFS_KMAP_ATOMIC,	/* use kmap_atomic() to map the buffer */
258 };
259 
260 struct erofs_buf {
261 	struct page *page;
262 	void *base;
263 	enum erofs_kmap_type kmap_type;
264 };
265 #define __EROFS_BUF_INITIALIZER	((struct erofs_buf){ .page = NULL })
266 
267 #define ROOT_NID(sb)		((sb)->root_nid)
268 
269 #define erofs_blknr(addr)       ((addr) / EROFS_BLKSIZ)
270 #define erofs_blkoff(addr)      ((addr) % EROFS_BLKSIZ)
271 #define blknr_to_addr(nr)       ((erofs_off_t)(nr) * EROFS_BLKSIZ)
272 
273 static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
274 {
275 	return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
276 }
277 
278 #define EROFS_FEATURE_FUNCS(name, compat, feature) \
279 static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \
280 { \
281 	return sbi->feature_##compat & EROFS_FEATURE_##feature; \
282 }
283 
284 EROFS_FEATURE_FUNCS(zero_padding, incompat, INCOMPAT_ZERO_PADDING)
285 EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
286 EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
287 EROFS_FEATURE_FUNCS(chunked_file, incompat, INCOMPAT_CHUNKED_FILE)
288 EROFS_FEATURE_FUNCS(device_table, incompat, INCOMPAT_DEVICE_TABLE)
289 EROFS_FEATURE_FUNCS(compr_head2, incompat, INCOMPAT_COMPR_HEAD2)
290 EROFS_FEATURE_FUNCS(ztailpacking, incompat, INCOMPAT_ZTAILPACKING)
291 EROFS_FEATURE_FUNCS(fragments, incompat, INCOMPAT_FRAGMENTS)
292 EROFS_FEATURE_FUNCS(dedupe, incompat, INCOMPAT_DEDUPE)
293 EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
294 
295 /* atomic flag definitions */
296 #define EROFS_I_EA_INITED_BIT	0
297 #define EROFS_I_Z_INITED_BIT	1
298 
299 /* bitlock definitions (arranged in reverse order) */
300 #define EROFS_I_BL_XATTR_BIT	(BITS_PER_LONG - 1)
301 #define EROFS_I_BL_Z_BIT	(BITS_PER_LONG - 2)
302 
303 struct erofs_inode {
304 	erofs_nid_t nid;
305 
306 	/* atomic flags (including bitlocks) */
307 	unsigned long flags;
308 
309 	unsigned char datalayout;
310 	unsigned char inode_isize;
311 	unsigned short xattr_isize;
312 
313 	unsigned int xattr_shared_count;
314 	unsigned int *xattr_shared_xattrs;
315 
316 	union {
317 		erofs_blk_t raw_blkaddr;
318 		struct {
319 			unsigned short	chunkformat;
320 			unsigned char	chunkbits;
321 		};
322 #ifdef CONFIG_EROFS_FS_ZIP
323 		struct {
324 			unsigned short z_advise;
325 			unsigned char  z_algorithmtype[2];
326 			unsigned char  z_logical_clusterbits;
327 			unsigned long  z_tailextent_headlcn;
328 			union {
329 				struct {
330 					erofs_off_t    z_idataoff;
331 					unsigned short z_idata_size;
332 				};
333 				erofs_off_t z_fragmentoff;
334 			};
335 		};
336 #endif	/* CONFIG_EROFS_FS_ZIP */
337 	};
338 	/* the corresponding vfs inode */
339 	struct inode vfs_inode;
340 };
341 
342 #define EROFS_I(ptr)	\
343 	container_of(ptr, struct erofs_inode, vfs_inode)
344 
345 static inline unsigned long erofs_inode_datablocks(struct inode *inode)
346 {
347 	/* since i_size cannot be changed */
348 	return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
349 }
350 
351 static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
352 					  unsigned int bits)
353 {
354 
355 	return (value >> bit) & ((1 << bits) - 1);
356 }
357 
358 
359 static inline unsigned int erofs_inode_version(unsigned int value)
360 {
361 	return erofs_bitrange(value, EROFS_I_VERSION_BIT,
362 			      EROFS_I_VERSION_BITS);
363 }
364 
365 static inline unsigned int erofs_inode_datalayout(unsigned int value)
366 {
367 	return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
368 			      EROFS_I_DATALAYOUT_BITS);
369 }
370 
371 /*
372  * Different from grab_cache_page_nowait(), reclaiming is never triggered
373  * when allocating new pages.
374  */
375 static inline
376 struct page *erofs_grab_cache_page_nowait(struct address_space *mapping,
377 					  pgoff_t index)
378 {
379 	return pagecache_get_page(mapping, index,
380 			FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT,
381 			readahead_gfp_mask(mapping) & ~__GFP_RECLAIM);
382 }
383 
384 extern const struct super_operations erofs_sops;
385 extern struct file_system_type erofs_fs_type;
386 
387 extern const struct address_space_operations erofs_raw_access_aops;
388 extern const struct address_space_operations z_erofs_aops;
389 
390 enum {
391 	BH_Encoded = BH_PrivateStart,
392 	BH_FullMapped,
393 	BH_Fragment,
394 	BH_Partialref,
395 };
396 
397 /* Has a disk mapping */
398 #define EROFS_MAP_MAPPED	(1 << BH_Mapped)
399 /* Located in metadata (could be copied from bd_inode) */
400 #define EROFS_MAP_META		(1 << BH_Meta)
401 /* The extent is encoded */
402 #define EROFS_MAP_ENCODED	(1 << BH_Encoded)
403 /* The length of extent is full */
404 #define EROFS_MAP_FULL_MAPPED	(1 << BH_FullMapped)
405 /* Located in the special packed inode */
406 #define EROFS_MAP_FRAGMENT	(1 << BH_Fragment)
407 /* The extent refers to partial decompressed data */
408 #define EROFS_MAP_PARTIAL_REF	(1 << BH_Partialref)
409 
410 struct erofs_map_blocks {
411 	struct erofs_buf buf;
412 
413 	erofs_off_t m_pa, m_la;
414 	u64 m_plen, m_llen;
415 
416 	unsigned short m_deviceid;
417 	char m_algorithmformat;
418 	unsigned int m_flags;
419 };
420 
421 /* Flags used by erofs_map_blocks_flatmode() */
422 #define EROFS_GET_BLOCKS_RAW    0x0001
423 /*
424  * Used to get the exact decompressed length, e.g. fiemap (consider lookback
425  * approach instead if possible since it's more metadata lightweight.)
426  */
427 #define EROFS_GET_BLOCKS_FIEMAP	0x0002
428 /* Used to map the whole extent if non-negligible data is requested for LZMA */
429 #define EROFS_GET_BLOCKS_READMORE	0x0004
430 /* Used to map tail extent for tailpacking inline or fragment pcluster */
431 #define EROFS_GET_BLOCKS_FINDTAIL	0x0008
432 
433 enum {
434 	Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,
435 	Z_EROFS_COMPRESSION_INTERLACED,
436 	Z_EROFS_COMPRESSION_RUNTIME_MAX
437 };
438 
439 /* zmap.c */
440 extern const struct iomap_ops z_erofs_iomap_report_ops;
441 
442 #ifdef CONFIG_EROFS_FS_ZIP
443 int z_erofs_fill_inode(struct inode *inode);
444 int z_erofs_map_blocks_iter(struct inode *inode,
445 			    struct erofs_map_blocks *map,
446 			    int flags);
447 #else
448 static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
449 static inline int z_erofs_map_blocks_iter(struct inode *inode,
450 					  struct erofs_map_blocks *map,
451 					  int flags)
452 {
453 	return -EOPNOTSUPP;
454 }
455 #endif	/* !CONFIG_EROFS_FS_ZIP */
456 
457 struct erofs_map_dev {
458 	struct erofs_fscache *m_fscache;
459 	struct block_device *m_bdev;
460 	struct dax_device *m_daxdev;
461 	u64 m_dax_part_off;
462 
463 	erofs_off_t m_pa;
464 	unsigned int m_deviceid;
465 };
466 
467 /* data.c */
468 extern const struct file_operations erofs_file_fops;
469 void erofs_unmap_metabuf(struct erofs_buf *buf);
470 void erofs_put_metabuf(struct erofs_buf *buf);
471 void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
472 		  erofs_blk_t blkaddr, enum erofs_kmap_type type);
473 void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
474 			 erofs_blk_t blkaddr, enum erofs_kmap_type type);
475 int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *dev);
476 int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
477 		 u64 start, u64 len);
478 int erofs_map_blocks(struct inode *inode,
479 		     struct erofs_map_blocks *map, int flags);
480 
481 /* inode.c */
482 static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
483 {
484 #if BITS_PER_LONG == 32
485 	return (nid >> 32) ^ (nid & 0xffffffff);
486 #else
487 	return nid;
488 #endif
489 }
490 
491 extern const struct inode_operations erofs_generic_iops;
492 extern const struct inode_operations erofs_symlink_iops;
493 extern const struct inode_operations erofs_fast_symlink_iops;
494 
495 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid);
496 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
497 		  struct kstat *stat, u32 request_mask,
498 		  unsigned int query_flags);
499 
500 /* namei.c */
501 extern const struct inode_operations erofs_dir_iops;
502 
503 int erofs_namei(struct inode *dir, const struct qstr *name,
504 		erofs_nid_t *nid, unsigned int *d_type);
505 
506 /* dir.c */
507 extern const struct file_operations erofs_dir_fops;
508 
509 static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
510 {
511 	int retried = 0;
512 
513 	while (1) {
514 		void *p = vm_map_ram(pages, count, -1);
515 
516 		/* retry two more times (totally 3 times) */
517 		if (p || ++retried >= 3)
518 			return p;
519 		vm_unmap_aliases();
520 	}
521 	return NULL;
522 }
523 
524 /* pcpubuf.c */
525 void *erofs_get_pcpubuf(unsigned int requiredpages);
526 void erofs_put_pcpubuf(void *ptr);
527 int erofs_pcpubuf_growsize(unsigned int nrpages);
528 void erofs_pcpubuf_init(void);
529 void erofs_pcpubuf_exit(void);
530 
531 /* sysfs.c */
532 int erofs_register_sysfs(struct super_block *sb);
533 void erofs_unregister_sysfs(struct super_block *sb);
534 int __init erofs_init_sysfs(void);
535 void erofs_exit_sysfs(void);
536 
537 /* utils.c / zdata.c */
538 struct page *erofs_allocpage(struct page **pagepool, gfp_t gfp);
539 static inline void erofs_pagepool_add(struct page **pagepool,
540 		struct page *page)
541 {
542 	set_page_private(page, (unsigned long)*pagepool);
543 	*pagepool = page;
544 }
545 void erofs_release_pages(struct page **pagepool);
546 
547 #ifdef CONFIG_EROFS_FS_ZIP
548 int erofs_workgroup_put(struct erofs_workgroup *grp);
549 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
550 					     pgoff_t index);
551 struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
552 					       struct erofs_workgroup *grp);
553 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
554 void erofs_shrinker_register(struct super_block *sb);
555 void erofs_shrinker_unregister(struct super_block *sb);
556 int __init erofs_init_shrinker(void);
557 void erofs_exit_shrinker(void);
558 int __init z_erofs_init_zip_subsystem(void);
559 void z_erofs_exit_zip_subsystem(void);
560 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
561 				       struct erofs_workgroup *egrp);
562 int erofs_try_to_free_cached_page(struct page *page);
563 int z_erofs_load_lz4_config(struct super_block *sb,
564 			    struct erofs_super_block *dsb,
565 			    struct z_erofs_lz4_cfgs *lz4, int len);
566 #else
567 static inline void erofs_shrinker_register(struct super_block *sb) {}
568 static inline void erofs_shrinker_unregister(struct super_block *sb) {}
569 static inline int erofs_init_shrinker(void) { return 0; }
570 static inline void erofs_exit_shrinker(void) {}
571 static inline int z_erofs_init_zip_subsystem(void) { return 0; }
572 static inline void z_erofs_exit_zip_subsystem(void) {}
573 static inline int z_erofs_load_lz4_config(struct super_block *sb,
574 				  struct erofs_super_block *dsb,
575 				  struct z_erofs_lz4_cfgs *lz4, int len)
576 {
577 	if (lz4 || dsb->u1.lz4_max_distance) {
578 		erofs_err(sb, "lz4 algorithm isn't enabled");
579 		return -EINVAL;
580 	}
581 	return 0;
582 }
583 #endif	/* !CONFIG_EROFS_FS_ZIP */
584 
585 #ifdef CONFIG_EROFS_FS_ZIP_LZMA
586 int z_erofs_lzma_init(void);
587 void z_erofs_lzma_exit(void);
588 int z_erofs_load_lzma_config(struct super_block *sb,
589 			     struct erofs_super_block *dsb,
590 			     struct z_erofs_lzma_cfgs *lzma, int size);
591 #else
592 static inline int z_erofs_lzma_init(void) { return 0; }
593 static inline int z_erofs_lzma_exit(void) { return 0; }
594 static inline int z_erofs_load_lzma_config(struct super_block *sb,
595 			     struct erofs_super_block *dsb,
596 			     struct z_erofs_lzma_cfgs *lzma, int size) {
597 	if (lzma) {
598 		erofs_err(sb, "lzma algorithm isn't enabled");
599 		return -EINVAL;
600 	}
601 	return 0;
602 }
603 #endif	/* !CONFIG_EROFS_FS_ZIP */
604 
605 /* fscache.c */
606 #ifdef CONFIG_EROFS_FS_ONDEMAND
607 int erofs_fscache_register_fs(struct super_block *sb);
608 void erofs_fscache_unregister_fs(struct super_block *sb);
609 
610 struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb,
611 						     char *name, bool need_inode);
612 void erofs_fscache_unregister_cookie(struct erofs_fscache *fscache);
613 
614 extern const struct address_space_operations erofs_fscache_access_aops;
615 #else
616 static inline int erofs_fscache_register_fs(struct super_block *sb)
617 {
618 	return -EOPNOTSUPP;
619 }
620 static inline void erofs_fscache_unregister_fs(struct super_block *sb) {}
621 
622 static inline
623 struct erofs_fscache *erofs_fscache_register_cookie(struct super_block *sb,
624 						     char *name, bool need_inode)
625 {
626 	return ERR_PTR(-EOPNOTSUPP);
627 }
628 
629 static inline void erofs_fscache_unregister_cookie(struct erofs_fscache *fscache)
630 {
631 }
632 #endif
633 
634 #define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
635 
636 #endif	/* __EROFS_INTERNAL_H */
637