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 block_device *bdev;
53 struct dax_device *dax_dev;
54
55 u32 blocks;
56 u32 mapped_blkaddr;
57 };
58
59 struct erofs_mount_opts {
60 #ifdef CONFIG_EROFS_FS_ZIP
61 /* current strategy of how to use managed cache */
62 unsigned char cache_strategy;
63 /* strategy of sync decompression (false - auto, true - force on) */
64 bool readahead_sync_decompress;
65
66 /* threshold for decompression synchronously */
67 unsigned int max_sync_decompress_pages;
68 #endif
69 unsigned int mount_opt;
70 };
71
72 struct erofs_dev_context {
73 struct idr tree;
74 struct rw_semaphore rwsem;
75
76 unsigned int extra_devices;
77 };
78
79 struct erofs_fs_context {
80 struct erofs_mount_opts opt;
81 struct erofs_dev_context *devs;
82 };
83
84 /* all filesystem-wide lz4 configurations */
85 struct erofs_sb_lz4_info {
86 /* # of pages needed for EROFS lz4 rolling decompression */
87 u16 max_distance_pages;
88 /* maximum possible blocks for pclusters in the filesystem */
89 u16 max_pclusterblks;
90 };
91
92 struct erofs_sb_info {
93 struct erofs_mount_opts opt; /* options */
94 #ifdef CONFIG_EROFS_FS_ZIP
95 /* list for all registered superblocks, mainly for shrinker */
96 struct list_head list;
97 struct mutex umount_mutex;
98
99 /* managed XArray arranged in physical block number */
100 struct xarray managed_pslots;
101
102 unsigned int shrinker_run_no;
103 u16 available_compr_algs;
104
105 /* pseudo inode to manage cached pages */
106 struct inode *managed_cache;
107
108 struct erofs_sb_lz4_info lz4;
109 #endif /* CONFIG_EROFS_FS_ZIP */
110 struct erofs_dev_context *devs;
111 struct dax_device *dax_dev;
112 u64 total_blocks;
113 u32 primarydevice_blocks;
114
115 u32 meta_blkaddr;
116 #ifdef CONFIG_EROFS_FS_XATTR
117 u32 xattr_blkaddr;
118 #endif
119 u16 device_id_mask; /* valid bits of device id to be used */
120
121 /* inode slot unit size in bit shift */
122 unsigned char islotbits;
123
124 u32 sb_size; /* total superblock size */
125 u32 build_time_nsec;
126 u64 build_time;
127
128 /* what we really care is nid, rather than ino.. */
129 erofs_nid_t root_nid;
130 /* used for statfs, f_files - f_favail */
131 u64 inos;
132
133 u8 uuid[16]; /* 128-bit uuid for volume */
134 u8 volume_name[16]; /* volume name */
135 u32 feature_compat;
136 u32 feature_incompat;
137 };
138
139 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
140 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
141
142 /* Mount flags set via mount options or defaults */
143 #define EROFS_MOUNT_XATTR_USER 0x00000010
144 #define EROFS_MOUNT_POSIX_ACL 0x00000020
145 #define EROFS_MOUNT_DAX_ALWAYS 0x00000040
146 #define EROFS_MOUNT_DAX_NEVER 0x00000080
147
148 #define clear_opt(opt, option) ((opt)->mount_opt &= ~EROFS_MOUNT_##option)
149 #define set_opt(opt, option) ((opt)->mount_opt |= EROFS_MOUNT_##option)
150 #define test_opt(opt, option) ((opt)->mount_opt & EROFS_MOUNT_##option)
151
152 enum {
153 EROFS_ZIP_CACHE_DISABLED,
154 EROFS_ZIP_CACHE_READAHEAD,
155 EROFS_ZIP_CACHE_READAROUND
156 };
157
158 #ifdef CONFIG_EROFS_FS_ZIP
159 #define EROFS_LOCKED_MAGIC (INT_MIN | 0xE0F510CCL)
160
161 /* basic unit of the workstation of a super_block */
162 struct erofs_workgroup {
163 /* the workgroup index in the workstation */
164 pgoff_t index;
165
166 /* overall workgroup reference count */
167 atomic_t refcount;
168 };
169
170 #if defined(CONFIG_SMP)
erofs_workgroup_try_to_freeze(struct erofs_workgroup * grp,int val)171 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
172 int val)
173 {
174 preempt_disable();
175 if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
176 preempt_enable();
177 return false;
178 }
179 return true;
180 }
181
erofs_workgroup_unfreeze(struct erofs_workgroup * grp,int orig_val)182 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
183 int orig_val)
184 {
185 /*
186 * other observers should notice all modifications
187 * in the freezing period.
188 */
189 smp_mb();
190 atomic_set(&grp->refcount, orig_val);
191 preempt_enable();
192 }
193
erofs_wait_on_workgroup_freezed(struct erofs_workgroup * grp)194 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
195 {
196 return atomic_cond_read_relaxed(&grp->refcount,
197 VAL != EROFS_LOCKED_MAGIC);
198 }
199 #else
erofs_workgroup_try_to_freeze(struct erofs_workgroup * grp,int val)200 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
201 int val)
202 {
203 preempt_disable();
204 /* no need to spin on UP platforms, let's just disable preemption. */
205 if (val != atomic_read(&grp->refcount)) {
206 preempt_enable();
207 return false;
208 }
209 return true;
210 }
211
erofs_workgroup_unfreeze(struct erofs_workgroup * grp,int orig_val)212 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
213 int orig_val)
214 {
215 preempt_enable();
216 }
217
erofs_wait_on_workgroup_freezed(struct erofs_workgroup * grp)218 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
219 {
220 int v = atomic_read(&grp->refcount);
221
222 /* workgroup is never freezed on uniprocessor systems */
223 DBG_BUGON(v == EROFS_LOCKED_MAGIC);
224 return v;
225 }
226 #endif /* !CONFIG_SMP */
227 #endif /* !CONFIG_EROFS_FS_ZIP */
228
229 /* we strictly follow PAGE_SIZE and no buffer head yet */
230 #define LOG_BLOCK_SIZE PAGE_SHIFT
231
232 #undef LOG_SECTORS_PER_BLOCK
233 #define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9)
234
235 #undef SECTORS_PER_BLOCK
236 #define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK)
237
238 #define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE)
239
240 #if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
241 #error erofs cannot be used in this platform
242 #endif
243
244 #define ROOT_NID(sb) ((sb)->root_nid)
245
246 #define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ)
247 #define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ)
248 #define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ)
249
iloc(struct erofs_sb_info * sbi,erofs_nid_t nid)250 static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
251 {
252 return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
253 }
254
255 #define EROFS_FEATURE_FUNCS(name, compat, feature) \
256 static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \
257 { \
258 return sbi->feature_##compat & EROFS_FEATURE_##feature; \
259 }
260
261 EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
262 EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
263 EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
264 EROFS_FEATURE_FUNCS(device_table, incompat, INCOMPAT_DEVICE_TABLE)
265 EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
266
267 /* atomic flag definitions */
268 #define EROFS_I_EA_INITED_BIT 0
269 #define EROFS_I_Z_INITED_BIT 1
270
271 /* bitlock definitions (arranged in reverse order) */
272 #define EROFS_I_BL_XATTR_BIT (BITS_PER_LONG - 1)
273 #define EROFS_I_BL_Z_BIT (BITS_PER_LONG - 2)
274
275 struct erofs_inode {
276 erofs_nid_t nid;
277
278 /* atomic flags (including bitlocks) */
279 unsigned long flags;
280
281 unsigned char datalayout;
282 unsigned char inode_isize;
283 unsigned short xattr_isize;
284
285 unsigned int xattr_shared_count;
286 unsigned int *xattr_shared_xattrs;
287
288 union {
289 erofs_blk_t raw_blkaddr;
290 struct {
291 unsigned short chunkformat;
292 unsigned char chunkbits;
293 };
294 #ifdef CONFIG_EROFS_FS_ZIP
295 struct {
296 unsigned short z_advise;
297 unsigned char z_algorithmtype[2];
298 unsigned char z_logical_clusterbits;
299 };
300 #endif /* CONFIG_EROFS_FS_ZIP */
301 };
302 /* the corresponding vfs inode */
303 struct inode vfs_inode;
304 };
305
306 #define EROFS_I(ptr) \
307 container_of(ptr, struct erofs_inode, vfs_inode)
308
erofs_inode_datablocks(struct inode * inode)309 static inline unsigned long erofs_inode_datablocks(struct inode *inode)
310 {
311 /* since i_size cannot be changed */
312 return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
313 }
314
erofs_bitrange(unsigned int value,unsigned int bit,unsigned int bits)315 static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
316 unsigned int bits)
317 {
318
319 return (value >> bit) & ((1 << bits) - 1);
320 }
321
322
erofs_inode_version(unsigned int value)323 static inline unsigned int erofs_inode_version(unsigned int value)
324 {
325 return erofs_bitrange(value, EROFS_I_VERSION_BIT,
326 EROFS_I_VERSION_BITS);
327 }
328
erofs_inode_datalayout(unsigned int value)329 static inline unsigned int erofs_inode_datalayout(unsigned int value)
330 {
331 return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
332 EROFS_I_DATALAYOUT_BITS);
333 }
334
335 /*
336 * Different from grab_cache_page_nowait(), reclaiming is never triggered
337 * when allocating new pages.
338 */
339 static inline
erofs_grab_cache_page_nowait(struct address_space * mapping,pgoff_t index)340 struct page *erofs_grab_cache_page_nowait(struct address_space *mapping,
341 pgoff_t index)
342 {
343 return pagecache_get_page(mapping, index,
344 FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT,
345 readahead_gfp_mask(mapping) & ~__GFP_RECLAIM);
346 }
347
348 extern const struct super_operations erofs_sops;
349
350 extern const struct address_space_operations erofs_raw_access_aops;
351 extern const struct address_space_operations z_erofs_aops;
352
353 /*
354 * Logical to physical block mapping
355 *
356 * Different with other file systems, it is used for 2 access modes:
357 *
358 * 1) RAW access mode:
359 *
360 * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
361 * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
362 *
363 * Note that m_lblk in the RAW access mode refers to the number of
364 * the compressed ondisk block rather than the uncompressed
365 * in-memory block for the compressed file.
366 *
367 * m_pofs equals to m_lofs except for the inline data page.
368 *
369 * 2) Normal access mode:
370 *
371 * If the inode is not compressed, it has no difference with
372 * the RAW access mode. However, if the inode is compressed,
373 * users should pass a valid (m_lblk, m_lofs) pair, and get
374 * the needed m_pblk, m_pofs, m_len to get the compressed data
375 * and the updated m_lblk, m_lofs which indicates the start
376 * of the corresponding uncompressed data in the file.
377 */
378 enum {
379 BH_Encoded = BH_PrivateStart,
380 BH_FullMapped,
381 };
382
383 /* Has a disk mapping */
384 #define EROFS_MAP_MAPPED (1 << BH_Mapped)
385 /* Located in metadata (could be copied from bd_inode) */
386 #define EROFS_MAP_META (1 << BH_Meta)
387 /* The extent is encoded */
388 #define EROFS_MAP_ENCODED (1 << BH_Encoded)
389 /* The length of extent is full */
390 #define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped)
391
392 struct erofs_map_blocks {
393 erofs_off_t m_pa, m_la;
394 u64 m_plen, m_llen;
395
396 unsigned short m_deviceid;
397 char m_algorithmformat;
398 unsigned int m_flags;
399
400 struct page *mpage;
401 };
402
403 /* Flags used by erofs_map_blocks_flatmode() */
404 #define EROFS_GET_BLOCKS_RAW 0x0001
405 /*
406 * Used to get the exact decompressed length, e.g. fiemap (consider lookback
407 * approach instead if possible since it's more metadata lightweight.)
408 */
409 #define EROFS_GET_BLOCKS_FIEMAP 0x0002
410 /* Used to map the whole extent if non-negligible data is requested for LZMA */
411 #define EROFS_GET_BLOCKS_READMORE 0x0004
412
413 enum {
414 Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,
415 Z_EROFS_COMPRESSION_RUNTIME_MAX
416 };
417
418 /* zmap.c */
419 extern const struct iomap_ops z_erofs_iomap_report_ops;
420
421 #ifdef CONFIG_EROFS_FS_ZIP
422 int z_erofs_fill_inode(struct inode *inode);
423 int z_erofs_map_blocks_iter(struct inode *inode,
424 struct erofs_map_blocks *map,
425 int flags);
426 #else
z_erofs_fill_inode(struct inode * inode)427 static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
z_erofs_map_blocks_iter(struct inode * inode,struct erofs_map_blocks * map,int flags)428 static inline int z_erofs_map_blocks_iter(struct inode *inode,
429 struct erofs_map_blocks *map,
430 int flags)
431 {
432 return -EOPNOTSUPP;
433 }
434 #endif /* !CONFIG_EROFS_FS_ZIP */
435
436 struct erofs_map_dev {
437 struct block_device *m_bdev;
438 struct dax_device *m_daxdev;
439
440 erofs_off_t m_pa;
441 unsigned int m_deviceid;
442 };
443
444 /* data.c */
445 extern const struct file_operations erofs_file_fops;
446 struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
447 int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *dev);
448 int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
449 u64 start, u64 len);
450
451 /* inode.c */
erofs_inode_hash(erofs_nid_t nid)452 static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
453 {
454 #if BITS_PER_LONG == 32
455 return (nid >> 32) ^ (nid & 0xffffffff);
456 #else
457 return nid;
458 #endif
459 }
460
461 extern const struct inode_operations erofs_generic_iops;
462 extern const struct inode_operations erofs_symlink_iops;
463 extern const struct inode_operations erofs_fast_symlink_iops;
464
465 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
466 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path,
467 struct kstat *stat, u32 request_mask,
468 unsigned int query_flags);
469
470 /* namei.c */
471 extern const struct inode_operations erofs_dir_iops;
472
473 int erofs_namei(struct inode *dir, struct qstr *name,
474 erofs_nid_t *nid, unsigned int *d_type);
475
476 /* dir.c */
477 extern const struct file_operations erofs_dir_fops;
478
erofs_vm_map_ram(struct page ** pages,unsigned int count)479 static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
480 {
481 int retried = 0;
482
483 while (1) {
484 void *p = vm_map_ram(pages, count, -1);
485
486 /* retry two more times (totally 3 times) */
487 if (p || ++retried >= 3)
488 return p;
489 vm_unmap_aliases();
490 }
491 return NULL;
492 }
493
494 /* pcpubuf.c */
495 void *erofs_get_pcpubuf(unsigned int requiredpages);
496 void erofs_put_pcpubuf(void *ptr);
497 int erofs_pcpubuf_growsize(unsigned int nrpages);
498 void erofs_pcpubuf_init(void);
499 void erofs_pcpubuf_exit(void);
500
501 /* utils.c / zdata.c */
502 struct page *erofs_allocpage(struct page **pagepool, gfp_t gfp);
erofs_pagepool_add(struct page ** pagepool,struct page * page)503 static inline void erofs_pagepool_add(struct page **pagepool,
504 struct page *page)
505 {
506 set_page_private(page, (unsigned long)*pagepool);
507 *pagepool = page;
508 }
509 void erofs_release_pages(struct page **pagepool);
510
511 #ifdef CONFIG_EROFS_FS_ZIP
512 int erofs_workgroup_put(struct erofs_workgroup *grp);
513 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
514 pgoff_t index);
515 struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
516 struct erofs_workgroup *grp);
517 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
518 void erofs_shrinker_register(struct super_block *sb);
519 void erofs_shrinker_unregister(struct super_block *sb);
520 int __init erofs_init_shrinker(void);
521 void erofs_exit_shrinker(void);
522 int __init z_erofs_init_zip_subsystem(void);
523 void z_erofs_exit_zip_subsystem(void);
524 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
525 struct erofs_workgroup *egrp);
526 int erofs_try_to_free_cached_page(struct page *page);
527 int z_erofs_load_lz4_config(struct super_block *sb,
528 struct erofs_super_block *dsb,
529 struct z_erofs_lz4_cfgs *lz4, int len);
530 #else
erofs_shrinker_register(struct super_block * sb)531 static inline void erofs_shrinker_register(struct super_block *sb) {}
erofs_shrinker_unregister(struct super_block * sb)532 static inline void erofs_shrinker_unregister(struct super_block *sb) {}
erofs_init_shrinker(void)533 static inline int erofs_init_shrinker(void) { return 0; }
erofs_exit_shrinker(void)534 static inline void erofs_exit_shrinker(void) {}
z_erofs_init_zip_subsystem(void)535 static inline int z_erofs_init_zip_subsystem(void) { return 0; }
z_erofs_exit_zip_subsystem(void)536 static inline void z_erofs_exit_zip_subsystem(void) {}
z_erofs_load_lz4_config(struct super_block * sb,struct erofs_super_block * dsb,struct z_erofs_lz4_cfgs * lz4,int len)537 static inline int 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 {
541 if (lz4 || dsb->u1.lz4_max_distance) {
542 erofs_err(sb, "lz4 algorithm isn't enabled");
543 return -EINVAL;
544 }
545 return 0;
546 }
547 #endif /* !CONFIG_EROFS_FS_ZIP */
548
549 #ifdef CONFIG_EROFS_FS_ZIP_LZMA
550 int z_erofs_lzma_init(void);
551 void z_erofs_lzma_exit(void);
552 int z_erofs_load_lzma_config(struct super_block *sb,
553 struct erofs_super_block *dsb,
554 struct z_erofs_lzma_cfgs *lzma, int size);
555 #else
z_erofs_lzma_init(void)556 static inline int z_erofs_lzma_init(void) { return 0; }
z_erofs_lzma_exit(void)557 static inline int z_erofs_lzma_exit(void) { return 0; }
z_erofs_load_lzma_config(struct super_block * sb,struct erofs_super_block * dsb,struct z_erofs_lzma_cfgs * lzma,int size)558 static inline int z_erofs_load_lzma_config(struct super_block *sb,
559 struct erofs_super_block *dsb,
560 struct z_erofs_lzma_cfgs *lzma, int size) {
561 if (lzma) {
562 erofs_err(sb, "lzma algorithm isn't enabled");
563 return -EINVAL;
564 }
565 return 0;
566 }
567 #endif /* !CONFIG_EROFS_FS_ZIP */
568
569 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
570
571 #endif /* __EROFS_INTERNAL_H */
572