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