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
54 /* threshold for decompression synchronously */
55 unsigned int max_sync_decompress_pages;
56 #endif
57 unsigned int mount_opt;
58 };
59
60 struct erofs_sb_info {
61 #ifdef CONFIG_EROFS_FS_ZIP
62 /* list for all registered superblocks, mainly for shrinker */
63 struct list_head list;
64 struct mutex umount_mutex;
65
66 /* managed XArray arranged in physical block number */
67 struct xarray managed_pslots;
68
69 unsigned int shrinker_run_no;
70
71 /* pseudo inode to manage cached pages */
72 struct inode *managed_cache;
73 #endif /* CONFIG_EROFS_FS_ZIP */
74 u32 blocks;
75 u32 meta_blkaddr;
76 #ifdef CONFIG_EROFS_FS_XATTR
77 u32 xattr_blkaddr;
78 #endif
79
80 /* inode slot unit size in bit shift */
81 unsigned char islotbits;
82
83 u32 build_time_nsec;
84 u64 build_time;
85
86 /* what we really care is nid, rather than ino.. */
87 erofs_nid_t root_nid;
88 /* used for statfs, f_files - f_favail */
89 u64 inos;
90
91 u8 uuid[16]; /* 128-bit uuid for volume */
92 u8 volume_name[16]; /* volume name */
93 u32 feature_compat;
94 u32 feature_incompat;
95
96 struct erofs_fs_context ctx; /* options */
97 };
98
99 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
100 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
101
102 /* Mount flags set via mount options or defaults */
103 #define EROFS_MOUNT_XATTR_USER 0x00000010
104 #define EROFS_MOUNT_POSIX_ACL 0x00000020
105
106 #define clear_opt(ctx, option) ((ctx)->mount_opt &= ~EROFS_MOUNT_##option)
107 #define set_opt(ctx, option) ((ctx)->mount_opt |= EROFS_MOUNT_##option)
108 #define test_opt(ctx, option) ((ctx)->mount_opt & EROFS_MOUNT_##option)
109
110 enum {
111 EROFS_ZIP_CACHE_DISABLED,
112 EROFS_ZIP_CACHE_READAHEAD,
113 EROFS_ZIP_CACHE_READAROUND
114 };
115
116 #ifdef CONFIG_EROFS_FS_ZIP
117 #define EROFS_LOCKED_MAGIC (INT_MIN | 0xE0F510CCL)
118
119 /* basic unit of the workstation of a super_block */
120 struct erofs_workgroup {
121 /* the workgroup index in the workstation */
122 pgoff_t index;
123
124 /* overall workgroup reference count */
125 atomic_t refcount;
126 };
127
128 #if defined(CONFIG_SMP)
erofs_workgroup_try_to_freeze(struct erofs_workgroup * grp,int val)129 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
130 int val)
131 {
132 preempt_disable();
133 if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
134 preempt_enable();
135 return false;
136 }
137 return true;
138 }
139
erofs_workgroup_unfreeze(struct erofs_workgroup * grp,int orig_val)140 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
141 int orig_val)
142 {
143 /*
144 * other observers should notice all modifications
145 * in the freezing period.
146 */
147 smp_mb();
148 atomic_set(&grp->refcount, orig_val);
149 preempt_enable();
150 }
151
erofs_wait_on_workgroup_freezed(struct erofs_workgroup * grp)152 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
153 {
154 return atomic_cond_read_relaxed(&grp->refcount,
155 VAL != EROFS_LOCKED_MAGIC);
156 }
157 #else
erofs_workgroup_try_to_freeze(struct erofs_workgroup * grp,int val)158 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
159 int val)
160 {
161 preempt_disable();
162 /* no need to spin on UP platforms, let's just disable preemption. */
163 if (val != atomic_read(&grp->refcount)) {
164 preempt_enable();
165 return false;
166 }
167 return true;
168 }
169
erofs_workgroup_unfreeze(struct erofs_workgroup * grp,int orig_val)170 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
171 int orig_val)
172 {
173 preempt_enable();
174 }
175
erofs_wait_on_workgroup_freezed(struct erofs_workgroup * grp)176 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
177 {
178 int v = atomic_read(&grp->refcount);
179
180 /* workgroup is never freezed on uniprocessor systems */
181 DBG_BUGON(v == EROFS_LOCKED_MAGIC);
182 return v;
183 }
184 #endif /* !CONFIG_SMP */
185
186 /* hard limit of pages per compressed cluster */
187 #define Z_EROFS_CLUSTER_MAX_PAGES (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
188 #define EROFS_PCPUBUF_NR_PAGES Z_EROFS_CLUSTER_MAX_PAGES
189 #else
190 #define EROFS_PCPUBUF_NR_PAGES 0
191 #endif /* !CONFIG_EROFS_FS_ZIP */
192
193 /* we strictly follow PAGE_SIZE and no buffer head yet */
194 #define LOG_BLOCK_SIZE PAGE_SHIFT
195
196 #undef LOG_SECTORS_PER_BLOCK
197 #define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9)
198
199 #undef SECTORS_PER_BLOCK
200 #define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK)
201
202 #define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE)
203
204 #if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
205 #error erofs cannot be used in this platform
206 #endif
207
208 #define ROOT_NID(sb) ((sb)->root_nid)
209
210 #define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ)
211 #define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ)
212 #define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ)
213
iloc(struct erofs_sb_info * sbi,erofs_nid_t nid)214 static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
215 {
216 return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
217 }
218
219 /* atomic flag definitions */
220 #define EROFS_I_EA_INITED_BIT 0
221 #define EROFS_I_Z_INITED_BIT 1
222
223 /* bitlock definitions (arranged in reverse order) */
224 #define EROFS_I_BL_XATTR_BIT (BITS_PER_LONG - 1)
225 #define EROFS_I_BL_Z_BIT (BITS_PER_LONG - 2)
226
227 struct erofs_inode {
228 erofs_nid_t nid;
229
230 /* atomic flags (including bitlocks) */
231 unsigned long flags;
232
233 unsigned char datalayout;
234 unsigned char inode_isize;
235 unsigned short xattr_isize;
236
237 unsigned int xattr_shared_count;
238 unsigned int *xattr_shared_xattrs;
239
240 union {
241 erofs_blk_t raw_blkaddr;
242 #ifdef CONFIG_EROFS_FS_ZIP
243 struct {
244 unsigned short z_advise;
245 unsigned char z_algorithmtype[2];
246 unsigned char z_logical_clusterbits;
247 unsigned char z_physical_clusterbits[2];
248 };
249 #endif /* CONFIG_EROFS_FS_ZIP */
250 };
251 /* the corresponding vfs inode */
252 struct inode vfs_inode;
253 };
254
255 #define EROFS_I(ptr) \
256 container_of(ptr, struct erofs_inode, vfs_inode)
257
erofs_inode_datablocks(struct inode * inode)258 static inline unsigned long erofs_inode_datablocks(struct inode *inode)
259 {
260 /* since i_size cannot be changed */
261 return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
262 }
263
erofs_bitrange(unsigned int value,unsigned int bit,unsigned int bits)264 static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
265 unsigned int bits)
266 {
267
268 return (value >> bit) & ((1 << bits) - 1);
269 }
270
271
erofs_inode_version(unsigned int value)272 static inline unsigned int erofs_inode_version(unsigned int value)
273 {
274 return erofs_bitrange(value, EROFS_I_VERSION_BIT,
275 EROFS_I_VERSION_BITS);
276 }
277
erofs_inode_datalayout(unsigned int value)278 static inline unsigned int erofs_inode_datalayout(unsigned int value)
279 {
280 return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
281 EROFS_I_DATALAYOUT_BITS);
282 }
283
284 extern const struct super_operations erofs_sops;
285
286 extern const struct address_space_operations erofs_raw_access_aops;
287 extern const struct address_space_operations z_erofs_aops;
288
289 /*
290 * Logical to physical block mapping, used by erofs_map_blocks()
291 *
292 * Different with other file systems, it is used for 2 access modes:
293 *
294 * 1) RAW access mode:
295 *
296 * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
297 * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
298 *
299 * Note that m_lblk in the RAW access mode refers to the number of
300 * the compressed ondisk block rather than the uncompressed
301 * in-memory block for the compressed file.
302 *
303 * m_pofs equals to m_lofs except for the inline data page.
304 *
305 * 2) Normal access mode:
306 *
307 * If the inode is not compressed, it has no difference with
308 * the RAW access mode. However, if the inode is compressed,
309 * users should pass a valid (m_lblk, m_lofs) pair, and get
310 * the needed m_pblk, m_pofs, m_len to get the compressed data
311 * and the updated m_lblk, m_lofs which indicates the start
312 * of the corresponding uncompressed data in the file.
313 */
314 enum {
315 BH_Zipped = BH_PrivateStart,
316 BH_FullMapped,
317 };
318
319 /* Has a disk mapping */
320 #define EROFS_MAP_MAPPED (1 << BH_Mapped)
321 /* Located in metadata (could be copied from bd_inode) */
322 #define EROFS_MAP_META (1 << BH_Meta)
323 /* The extent has been compressed */
324 #define EROFS_MAP_ZIPPED (1 << BH_Zipped)
325 /* The length of extent is full */
326 #define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped)
327
328 struct erofs_map_blocks {
329 erofs_off_t m_pa, m_la;
330 u64 m_plen, m_llen;
331
332 unsigned int m_flags;
333
334 struct page *mpage;
335 };
336
337 /* Flags used by erofs_map_blocks() */
338 #define EROFS_GET_BLOCKS_RAW 0x0001
339
340 /* zmap.c */
341 #ifdef CONFIG_EROFS_FS_ZIP
342 int z_erofs_fill_inode(struct inode *inode);
343 int z_erofs_map_blocks_iter(struct inode *inode,
344 struct erofs_map_blocks *map,
345 int flags);
346 #else
z_erofs_fill_inode(struct inode * inode)347 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)348 static inline int z_erofs_map_blocks_iter(struct inode *inode,
349 struct erofs_map_blocks *map,
350 int flags)
351 {
352 return -EOPNOTSUPP;
353 }
354 #endif /* !CONFIG_EROFS_FS_ZIP */
355
356 /* data.c */
357 struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
358
359 int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
360
361 /* inode.c */
erofs_inode_hash(erofs_nid_t nid)362 static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
363 {
364 #if BITS_PER_LONG == 32
365 return (nid >> 32) ^ (nid & 0xffffffff);
366 #else
367 return nid;
368 #endif
369 }
370
371 extern const struct inode_operations erofs_generic_iops;
372 extern const struct inode_operations erofs_symlink_iops;
373 extern const struct inode_operations erofs_fast_symlink_iops;
374
375 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
376 int erofs_getattr(const struct path *path, struct kstat *stat,
377 u32 request_mask, unsigned int query_flags);
378
379 /* namei.c */
380 extern const struct inode_operations erofs_dir_iops;
381
382 int erofs_namei(struct inode *dir, struct qstr *name,
383 erofs_nid_t *nid, unsigned int *d_type);
384
385 /* dir.c */
386 extern const struct file_operations erofs_dir_fops;
387
388 /* utils.c / zdata.c */
389 struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
390
391 #if (EROFS_PCPUBUF_NR_PAGES > 0)
392 void *erofs_get_pcpubuf(unsigned int pagenr);
393 #define erofs_put_pcpubuf(buf) do { \
394 (void)&(buf); \
395 preempt_enable(); \
396 } while (0)
397 #else
erofs_get_pcpubuf(unsigned int pagenr)398 static inline void *erofs_get_pcpubuf(unsigned int pagenr)
399 {
400 return ERR_PTR(-EOPNOTSUPP);
401 }
402
403 #define erofs_put_pcpubuf(buf) do {} while (0)
404 #endif
405
406 #ifdef CONFIG_EROFS_FS_ZIP
407 int erofs_workgroup_put(struct erofs_workgroup *grp);
408 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
409 pgoff_t index);
410 struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
411 struct erofs_workgroup *grp);
412 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
413 void erofs_shrinker_register(struct super_block *sb);
414 void erofs_shrinker_unregister(struct super_block *sb);
415 int __init erofs_init_shrinker(void);
416 void erofs_exit_shrinker(void);
417 int __init z_erofs_init_zip_subsystem(void);
418 void z_erofs_exit_zip_subsystem(void);
419 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
420 struct erofs_workgroup *egrp);
421 int erofs_try_to_free_cached_page(struct address_space *mapping,
422 struct page *page);
423 #else
erofs_shrinker_register(struct super_block * sb)424 static inline void erofs_shrinker_register(struct super_block *sb) {}
erofs_shrinker_unregister(struct super_block * sb)425 static inline void erofs_shrinker_unregister(struct super_block *sb) {}
erofs_init_shrinker(void)426 static inline int erofs_init_shrinker(void) { return 0; }
erofs_exit_shrinker(void)427 static inline void erofs_exit_shrinker(void) {}
z_erofs_init_zip_subsystem(void)428 static inline int z_erofs_init_zip_subsystem(void) { return 0; }
z_erofs_exit_zip_subsystem(void)429 static inline void z_erofs_exit_zip_subsystem(void) {}
430 #endif /* !CONFIG_EROFS_FS_ZIP */
431
432 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
433
434 #endif /* __EROFS_INTERNAL_H */
435
436