1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2017-2018 HUAWEI, Inc.
4 * https://www.huawei.com/
5 * Created by Gao Xiang <gaoxiang25@huawei.com>
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 "erofs_fs.h"
20
21 /* redefine pr_fmt "erofs: " */
22 #undef pr_fmt
23 #define pr_fmt(fmt) "erofs: " fmt
24
25 __printf(3, 4) void _erofs_err(struct super_block *sb,
26 const char *function, const char *fmt, ...);
27 #define erofs_err(sb, fmt, ...) \
28 _erofs_err(sb, __func__, fmt "\n", ##__VA_ARGS__)
29 __printf(3, 4) void _erofs_info(struct super_block *sb,
30 const char *function, const char *fmt, ...);
31 #define erofs_info(sb, fmt, ...) \
32 _erofs_info(sb, __func__, fmt "\n", ##__VA_ARGS__)
33 #ifdef CONFIG_EROFS_FS_DEBUG
34 #define erofs_dbg(x, ...) pr_debug(x "\n", ##__VA_ARGS__)
35 #define DBG_BUGON BUG_ON
36 #else
37 #define erofs_dbg(x, ...) ((void)0)
38 #define DBG_BUGON(x) ((void)(x))
39 #endif /* !CONFIG_EROFS_FS_DEBUG */
40
41 /* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
42 #define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1
43
44 typedef u64 erofs_nid_t;
45 typedef u64 erofs_off_t;
46 /* data type for filesystem-wide blocks number */
47 typedef u32 erofs_blk_t;
48
49 struct erofs_fs_context {
50 #ifdef CONFIG_EROFS_FS_ZIP
51 /* current strategy of how to use managed cache */
52 unsigned char cache_strategy;
53 /* strategy of sync decompression (false - auto, true - force on) */
54 bool readahead_sync_decompress;
55
56 /* threshold for decompression synchronously */
57 unsigned int max_sync_decompress_pages;
58 #endif
59 unsigned int mount_opt;
60 };
61
62 /* all filesystem-wide lz4 configurations */
63 struct erofs_sb_lz4_info {
64 /* # of pages needed for EROFS lz4 rolling decompression */
65 u16 max_distance_pages;
66 /* maximum possible blocks for pclusters in the filesystem */
67 u16 max_pclusterblks;
68 };
69
70 struct erofs_sb_info {
71 #ifdef CONFIG_EROFS_FS_ZIP
72 /* list for all registered superblocks, mainly for shrinker */
73 struct list_head list;
74 struct mutex umount_mutex;
75
76 /* managed XArray arranged in physical block number */
77 struct xarray managed_pslots;
78
79 unsigned int shrinker_run_no;
80 u16 available_compr_algs;
81
82 /* pseudo inode to manage cached pages */
83 struct inode *managed_cache;
84
85 struct erofs_sb_lz4_info lz4;
86 #endif /* CONFIG_EROFS_FS_ZIP */
87 u32 blocks;
88 u32 meta_blkaddr;
89 #ifdef CONFIG_EROFS_FS_XATTR
90 u32 xattr_blkaddr;
91 #endif
92
93 /* inode slot unit size in bit shift */
94 unsigned char islotbits;
95
96 u32 sb_size; /* total superblock size */
97 u32 build_time_nsec;
98 u64 build_time;
99
100 /* what we really care is nid, rather than ino.. */
101 erofs_nid_t root_nid;
102 /* used for statfs, f_files - f_favail */
103 u64 inos;
104
105 u8 uuid[16]; /* 128-bit uuid for volume */
106 u8 volume_name[16]; /* volume name */
107 u32 feature_compat;
108 u32 feature_incompat;
109
110 struct erofs_fs_context ctx; /* options */
111 };
112
113 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
114 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
115
116 /* Mount flags set via mount options or defaults */
117 #define EROFS_MOUNT_XATTR_USER 0x00000010
118 #define EROFS_MOUNT_POSIX_ACL 0x00000020
119
120 #define clear_opt(ctx, option) ((ctx)->mount_opt &= ~EROFS_MOUNT_##option)
121 #define set_opt(ctx, option) ((ctx)->mount_opt |= EROFS_MOUNT_##option)
122 #define test_opt(ctx, option) ((ctx)->mount_opt & EROFS_MOUNT_##option)
123
124 enum {
125 EROFS_ZIP_CACHE_DISABLED,
126 EROFS_ZIP_CACHE_READAHEAD,
127 EROFS_ZIP_CACHE_READAROUND
128 };
129
130 #ifdef CONFIG_EROFS_FS_ZIP
131 #define EROFS_LOCKED_MAGIC (INT_MIN | 0xE0F510CCL)
132
133 /* basic unit of the workstation of a super_block */
134 struct erofs_workgroup {
135 /* the workgroup index in the workstation */
136 pgoff_t index;
137
138 /* overall workgroup reference count */
139 atomic_t refcount;
140 };
141
142 #if defined(CONFIG_SMP)
erofs_workgroup_try_to_freeze(struct erofs_workgroup * grp,int val)143 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
144 int val)
145 {
146 preempt_disable();
147 if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
148 preempt_enable();
149 return false;
150 }
151 return true;
152 }
153
erofs_workgroup_unfreeze(struct erofs_workgroup * grp,int orig_val)154 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
155 int orig_val)
156 {
157 /*
158 * other observers should notice all modifications
159 * in the freezing period.
160 */
161 smp_mb();
162 atomic_set(&grp->refcount, orig_val);
163 preempt_enable();
164 }
165
erofs_wait_on_workgroup_freezed(struct erofs_workgroup * grp)166 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
167 {
168 return atomic_cond_read_relaxed(&grp->refcount,
169 VAL != EROFS_LOCKED_MAGIC);
170 }
171 #else
erofs_workgroup_try_to_freeze(struct erofs_workgroup * grp,int val)172 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
173 int val)
174 {
175 preempt_disable();
176 /* no need to spin on UP platforms, let's just disable preemption. */
177 if (val != atomic_read(&grp->refcount)) {
178 preempt_enable();
179 return false;
180 }
181 return true;
182 }
183
erofs_workgroup_unfreeze(struct erofs_workgroup * grp,int orig_val)184 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
185 int orig_val)
186 {
187 preempt_enable();
188 }
189
erofs_wait_on_workgroup_freezed(struct erofs_workgroup * grp)190 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
191 {
192 int v = atomic_read(&grp->refcount);
193
194 /* workgroup is never freezed on uniprocessor systems */
195 DBG_BUGON(v == EROFS_LOCKED_MAGIC);
196 return v;
197 }
198 #endif /* !CONFIG_SMP */
199 #endif /* !CONFIG_EROFS_FS_ZIP */
200
201 /* we strictly follow PAGE_SIZE and no buffer head yet */
202 #define LOG_BLOCK_SIZE PAGE_SHIFT
203
204 #undef LOG_SECTORS_PER_BLOCK
205 #define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9)
206
207 #undef SECTORS_PER_BLOCK
208 #define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK)
209
210 #define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE)
211
212 #if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
213 #error erofs cannot be used in this platform
214 #endif
215
216 #define ROOT_NID(sb) ((sb)->root_nid)
217
218 #define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ)
219 #define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ)
220 #define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ)
221
iloc(struct erofs_sb_info * sbi,erofs_nid_t nid)222 static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
223 {
224 return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
225 }
226
227 #define EROFS_FEATURE_FUNCS(name, compat, feature) \
228 static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \
229 { \
230 return sbi->feature_##compat & EROFS_FEATURE_##feature; \
231 }
232
233 EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
234 EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
235 EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
236 EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
237
238 /* atomic flag definitions */
239 #define EROFS_I_EA_INITED_BIT 0
240 #define EROFS_I_Z_INITED_BIT 1
241
242 /* bitlock definitions (arranged in reverse order) */
243 #define EROFS_I_BL_XATTR_BIT (BITS_PER_LONG - 1)
244 #define EROFS_I_BL_Z_BIT (BITS_PER_LONG - 2)
245
246 struct erofs_inode {
247 erofs_nid_t nid;
248
249 /* atomic flags (including bitlocks) */
250 unsigned long flags;
251
252 unsigned char datalayout;
253 unsigned char inode_isize;
254 unsigned int xattr_isize;
255
256 unsigned int xattr_shared_count;
257 unsigned int *xattr_shared_xattrs;
258
259 union {
260 erofs_blk_t raw_blkaddr;
261 #ifdef CONFIG_EROFS_FS_ZIP
262 struct {
263 unsigned short z_advise;
264 unsigned char z_algorithmtype[2];
265 unsigned char z_logical_clusterbits;
266 };
267 #endif /* CONFIG_EROFS_FS_ZIP */
268 };
269 /* the corresponding vfs inode */
270 struct inode vfs_inode;
271 };
272
273 #define EROFS_I(ptr) \
274 container_of(ptr, struct erofs_inode, vfs_inode)
275
erofs_inode_datablocks(struct inode * inode)276 static inline unsigned long erofs_inode_datablocks(struct inode *inode)
277 {
278 /* since i_size cannot be changed */
279 return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
280 }
281
erofs_bitrange(unsigned int value,unsigned int bit,unsigned int bits)282 static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
283 unsigned int bits)
284 {
285
286 return (value >> bit) & ((1 << bits) - 1);
287 }
288
289
erofs_inode_version(unsigned int value)290 static inline unsigned int erofs_inode_version(unsigned int value)
291 {
292 return erofs_bitrange(value, EROFS_I_VERSION_BIT,
293 EROFS_I_VERSION_BITS);
294 }
295
erofs_inode_datalayout(unsigned int value)296 static inline unsigned int erofs_inode_datalayout(unsigned int value)
297 {
298 return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
299 EROFS_I_DATALAYOUT_BITS);
300 }
301
302 extern const struct super_operations erofs_sops;
303
304 extern const struct address_space_operations erofs_raw_access_aops;
305 extern const struct address_space_operations z_erofs_aops;
306
307 /*
308 * Logical to physical block mapping
309 *
310 * Different with other file systems, it is used for 2 access modes:
311 *
312 * 1) RAW access mode:
313 *
314 * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
315 * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
316 *
317 * Note that m_lblk in the RAW access mode refers to the number of
318 * the compressed ondisk block rather than the uncompressed
319 * in-memory block for the compressed file.
320 *
321 * m_pofs equals to m_lofs except for the inline data page.
322 *
323 * 2) Normal access mode:
324 *
325 * If the inode is not compressed, it has no difference with
326 * the RAW access mode. However, if the inode is compressed,
327 * users should pass a valid (m_lblk, m_lofs) pair, and get
328 * the needed m_pblk, m_pofs, m_len to get the compressed data
329 * and the updated m_lblk, m_lofs which indicates the start
330 * of the corresponding uncompressed data in the file.
331 */
332 enum {
333 BH_Zipped = BH_PrivateStart,
334 BH_FullMapped,
335 };
336
337 /* Has a disk mapping */
338 #define EROFS_MAP_MAPPED (1 << BH_Mapped)
339 /* Located in metadata (could be copied from bd_inode) */
340 #define EROFS_MAP_META (1 << BH_Meta)
341 /* The extent has been compressed */
342 #define EROFS_MAP_ZIPPED (1 << BH_Zipped)
343 /* The length of extent is full */
344 #define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped)
345
346 struct erofs_map_blocks {
347 erofs_off_t m_pa, m_la;
348 u64 m_plen, m_llen;
349
350 unsigned int m_flags;
351
352 struct page *mpage;
353 };
354
355 /* Flags used by erofs_map_blocks_flatmode() */
356 #define EROFS_GET_BLOCKS_RAW 0x0001
357
358 /* zmap.c */
359 #ifdef CONFIG_EROFS_FS_ZIP
360 int z_erofs_fill_inode(struct inode *inode);
361 int z_erofs_map_blocks_iter(struct inode *inode,
362 struct erofs_map_blocks *map,
363 int flags);
364 #else
z_erofs_fill_inode(struct inode * inode)365 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)366 static inline int z_erofs_map_blocks_iter(struct inode *inode,
367 struct erofs_map_blocks *map,
368 int flags)
369 {
370 return -EOPNOTSUPP;
371 }
372 #endif /* !CONFIG_EROFS_FS_ZIP */
373
374 /* data.c */
375 struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
376
377 /* inode.c */
erofs_inode_hash(erofs_nid_t nid)378 static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
379 {
380 #if BITS_PER_LONG == 32
381 return (nid >> 32) ^ (nid & 0xffffffff);
382 #else
383 return nid;
384 #endif
385 }
386
387 extern const struct inode_operations erofs_generic_iops;
388 extern const struct inode_operations erofs_symlink_iops;
389 extern const struct inode_operations erofs_fast_symlink_iops;
390
391 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
392 int erofs_getattr(const struct path *path, struct kstat *stat,
393 u32 request_mask, unsigned int query_flags);
394
395 /* namei.c */
396 extern const struct inode_operations erofs_dir_iops;
397
398 int erofs_namei(struct inode *dir, struct qstr *name,
399 erofs_nid_t *nid, unsigned int *d_type);
400
401 /* dir.c */
402 extern const struct file_operations erofs_dir_fops;
403
erofs_vm_map_ram(struct page ** pages,unsigned int count)404 static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
405 {
406 int retried = 0;
407
408 while (1) {
409 void *p = vm_map_ram(pages, count, -1);
410
411 /* retry two more times (totally 3 times) */
412 if (p || ++retried >= 3)
413 return p;
414 vm_unmap_aliases();
415 }
416 return NULL;
417 }
418
419 /* pcpubuf.c */
420 void *erofs_get_pcpubuf(unsigned int requiredpages);
421 void erofs_put_pcpubuf(void *ptr);
422 int erofs_pcpubuf_growsize(unsigned int nrpages);
423 void erofs_pcpubuf_init(void);
424 void erofs_pcpubuf_exit(void);
425
426 /* utils.c / zdata.c */
427 struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
428
429 #ifdef CONFIG_EROFS_FS_ZIP
430 int erofs_workgroup_put(struct erofs_workgroup *grp);
431 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
432 pgoff_t index);
433 struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
434 struct erofs_workgroup *grp);
435 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
436 void erofs_shrinker_register(struct super_block *sb);
437 void erofs_shrinker_unregister(struct super_block *sb);
438 int __init erofs_init_shrinker(void);
439 void erofs_exit_shrinker(void);
440 int __init z_erofs_init_zip_subsystem(void);
441 void z_erofs_exit_zip_subsystem(void);
442 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
443 struct erofs_workgroup *egrp);
444 int erofs_try_to_free_cached_page(struct address_space *mapping,
445 struct page *page);
446 int z_erofs_load_lz4_config(struct super_block *sb,
447 struct erofs_super_block *dsb,
448 struct z_erofs_lz4_cfgs *lz4, int len);
449 #else
erofs_shrinker_register(struct super_block * sb)450 static inline void erofs_shrinker_register(struct super_block *sb) {}
erofs_shrinker_unregister(struct super_block * sb)451 static inline void erofs_shrinker_unregister(struct super_block *sb) {}
erofs_init_shrinker(void)452 static inline int erofs_init_shrinker(void) { return 0; }
erofs_exit_shrinker(void)453 static inline void erofs_exit_shrinker(void) {}
z_erofs_init_zip_subsystem(void)454 static inline int z_erofs_init_zip_subsystem(void) { return 0; }
z_erofs_exit_zip_subsystem(void)455 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)456 static inline int z_erofs_load_lz4_config(struct super_block *sb,
457 struct erofs_super_block *dsb,
458 struct z_erofs_lz4_cfgs *lz4, int len)
459 {
460 if (lz4 || dsb->u1.lz4_max_distance) {
461 erofs_err(sb, "lz4 algorithm isn't enabled");
462 return -EINVAL;
463 }
464 return 0;
465 }
466 #endif /* !CONFIG_EROFS_FS_ZIP */
467
468 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
469
470 #endif /* __EROFS_INTERNAL_H */
471
472