internal.h 13 KB

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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. * Created by Gao Xiang <gaoxiang25@huawei.com>
  6. */
  7. #ifndef __EROFS_INTERNAL_H
  8. #define __EROFS_INTERNAL_H
  9. #include <linux/fs.h>
  10. #include <linux/dcache.h>
  11. #include <linux/mm.h>
  12. #include <linux/pagemap.h>
  13. #include <linux/bio.h>
  14. #include <linux/buffer_head.h>
  15. #include <linux/magic.h>
  16. #include <linux/slab.h>
  17. #include <linux/vmalloc.h>
  18. #include "erofs_fs.h"
  19. /* redefine pr_fmt "erofs: " */
  20. #undef pr_fmt
  21. #define pr_fmt(fmt) "erofs: " fmt
  22. __printf(3, 4) void _erofs_err(struct super_block *sb,
  23. const char *function, const char *fmt, ...);
  24. #define erofs_err(sb, fmt, ...) \
  25. _erofs_err(sb, __func__, fmt "\n", ##__VA_ARGS__)
  26. __printf(3, 4) void _erofs_info(struct super_block *sb,
  27. const char *function, const char *fmt, ...);
  28. #define erofs_info(sb, fmt, ...) \
  29. _erofs_info(sb, __func__, fmt "\n", ##__VA_ARGS__)
  30. #ifdef CONFIG_EROFS_FS_DEBUG
  31. #define erofs_dbg(x, ...) pr_debug(x "\n", ##__VA_ARGS__)
  32. #define DBG_BUGON BUG_ON
  33. #else
  34. #define erofs_dbg(x, ...) ((void)0)
  35. #define DBG_BUGON(x) ((void)(x))
  36. #endif /* !CONFIG_EROFS_FS_DEBUG */
  37. /* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
  38. #define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1
  39. typedef u64 erofs_nid_t;
  40. typedef u64 erofs_off_t;
  41. /* data type for filesystem-wide blocks number */
  42. typedef u32 erofs_blk_t;
  43. struct erofs_fs_context {
  44. #ifdef CONFIG_EROFS_FS_ZIP
  45. /* current strategy of how to use managed cache */
  46. unsigned char cache_strategy;
  47. /* strategy of sync decompression (false - auto, true - force on) */
  48. bool readahead_sync_decompress;
  49. /* threshold for decompression synchronously */
  50. unsigned int max_sync_decompress_pages;
  51. #endif
  52. unsigned int mount_opt;
  53. };
  54. /* all filesystem-wide lz4 configurations */
  55. struct erofs_sb_lz4_info {
  56. /* # of pages needed for EROFS lz4 rolling decompression */
  57. u16 max_distance_pages;
  58. /* maximum possible blocks for pclusters in the filesystem */
  59. u16 max_pclusterblks;
  60. };
  61. struct erofs_sb_info {
  62. #ifdef CONFIG_EROFS_FS_ZIP
  63. /* list for all registered superblocks, mainly for shrinker */
  64. struct list_head list;
  65. struct mutex umount_mutex;
  66. /* managed XArray arranged in physical block number */
  67. struct xarray managed_pslots;
  68. unsigned int shrinker_run_no;
  69. u16 available_compr_algs;
  70. /* pseudo inode to manage cached pages */
  71. struct inode *managed_cache;
  72. struct erofs_sb_lz4_info lz4;
  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. /* inode slot unit size in bit shift */
  80. unsigned char islotbits;
  81. u32 sb_size; /* total superblock size */
  82. u32 build_time_nsec;
  83. u64 build_time;
  84. /* what we really care is nid, rather than ino.. */
  85. erofs_nid_t root_nid;
  86. /* used for statfs, f_files - f_favail */
  87. u64 inos;
  88. u8 uuid[16]; /* 128-bit uuid for volume */
  89. u8 volume_name[16]; /* volume name */
  90. u32 feature_compat;
  91. u32 feature_incompat;
  92. struct erofs_fs_context ctx; /* options */
  93. };
  94. #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
  95. #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
  96. /* Mount flags set via mount options or defaults */
  97. #define EROFS_MOUNT_XATTR_USER 0x00000010
  98. #define EROFS_MOUNT_POSIX_ACL 0x00000020
  99. #define clear_opt(ctx, option) ((ctx)->mount_opt &= ~EROFS_MOUNT_##option)
  100. #define set_opt(ctx, option) ((ctx)->mount_opt |= EROFS_MOUNT_##option)
  101. #define test_opt(ctx, option) ((ctx)->mount_opt & EROFS_MOUNT_##option)
  102. enum {
  103. EROFS_ZIP_CACHE_DISABLED,
  104. EROFS_ZIP_CACHE_READAHEAD,
  105. EROFS_ZIP_CACHE_READAROUND
  106. };
  107. #ifdef CONFIG_EROFS_FS_ZIP
  108. #define EROFS_LOCKED_MAGIC (INT_MIN | 0xE0F510CCL)
  109. /* basic unit of the workstation of a super_block */
  110. struct erofs_workgroup {
  111. /* the workgroup index in the workstation */
  112. pgoff_t index;
  113. /* overall workgroup reference count */
  114. atomic_t refcount;
  115. };
  116. #if defined(CONFIG_SMP)
  117. static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
  118. int val)
  119. {
  120. preempt_disable();
  121. if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
  122. preempt_enable();
  123. return false;
  124. }
  125. return true;
  126. }
  127. static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
  128. int orig_val)
  129. {
  130. /*
  131. * other observers should notice all modifications
  132. * in the freezing period.
  133. */
  134. smp_mb();
  135. atomic_set(&grp->refcount, orig_val);
  136. preempt_enable();
  137. }
  138. static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
  139. {
  140. return atomic_cond_read_relaxed(&grp->refcount,
  141. VAL != EROFS_LOCKED_MAGIC);
  142. }
  143. #else
  144. static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
  145. int val)
  146. {
  147. preempt_disable();
  148. /* no need to spin on UP platforms, let's just disable preemption. */
  149. if (val != atomic_read(&grp->refcount)) {
  150. preempt_enable();
  151. return false;
  152. }
  153. return true;
  154. }
  155. static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
  156. int orig_val)
  157. {
  158. preempt_enable();
  159. }
  160. static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
  161. {
  162. int v = atomic_read(&grp->refcount);
  163. /* workgroup is never freezed on uniprocessor systems */
  164. DBG_BUGON(v == EROFS_LOCKED_MAGIC);
  165. return v;
  166. }
  167. #endif /* !CONFIG_SMP */
  168. #endif /* !CONFIG_EROFS_FS_ZIP */
  169. /* we strictly follow PAGE_SIZE and no buffer head yet */
  170. #define LOG_BLOCK_SIZE PAGE_SHIFT
  171. #undef LOG_SECTORS_PER_BLOCK
  172. #define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9)
  173. #undef SECTORS_PER_BLOCK
  174. #define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK)
  175. #define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE)
  176. #if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
  177. #error erofs cannot be used in this platform
  178. #endif
  179. #define ROOT_NID(sb) ((sb)->root_nid)
  180. #define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ)
  181. #define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ)
  182. #define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ)
  183. static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
  184. {
  185. return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
  186. }
  187. #define EROFS_FEATURE_FUNCS(name, compat, feature) \
  188. static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \
  189. { \
  190. return sbi->feature_##compat & EROFS_FEATURE_##feature; \
  191. }
  192. EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
  193. EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
  194. EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
  195. EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
  196. /* atomic flag definitions */
  197. #define EROFS_I_EA_INITED_BIT 0
  198. #define EROFS_I_Z_INITED_BIT 1
  199. /* bitlock definitions (arranged in reverse order) */
  200. #define EROFS_I_BL_XATTR_BIT (BITS_PER_LONG - 1)
  201. #define EROFS_I_BL_Z_BIT (BITS_PER_LONG - 2)
  202. struct erofs_inode {
  203. erofs_nid_t nid;
  204. /* atomic flags (including bitlocks) */
  205. unsigned long flags;
  206. unsigned char datalayout;
  207. unsigned char inode_isize;
  208. unsigned short xattr_isize;
  209. unsigned int xattr_shared_count;
  210. unsigned int *xattr_shared_xattrs;
  211. union {
  212. erofs_blk_t raw_blkaddr;
  213. #ifdef CONFIG_EROFS_FS_ZIP
  214. struct {
  215. unsigned short z_advise;
  216. unsigned char z_algorithmtype[2];
  217. unsigned char z_logical_clusterbits;
  218. };
  219. #endif /* CONFIG_EROFS_FS_ZIP */
  220. };
  221. /* the corresponding vfs inode */
  222. struct inode vfs_inode;
  223. };
  224. #define EROFS_I(ptr) \
  225. container_of(ptr, struct erofs_inode, vfs_inode)
  226. static inline unsigned long erofs_inode_datablocks(struct inode *inode)
  227. {
  228. /* since i_size cannot be changed */
  229. return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
  230. }
  231. static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
  232. unsigned int bits)
  233. {
  234. return (value >> bit) & ((1 << bits) - 1);
  235. }
  236. static inline unsigned int erofs_inode_version(unsigned int value)
  237. {
  238. return erofs_bitrange(value, EROFS_I_VERSION_BIT,
  239. EROFS_I_VERSION_BITS);
  240. }
  241. static inline unsigned int erofs_inode_datalayout(unsigned int value)
  242. {
  243. return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
  244. EROFS_I_DATALAYOUT_BITS);
  245. }
  246. extern const struct super_operations erofs_sops;
  247. extern const struct address_space_operations erofs_raw_access_aops;
  248. extern const struct address_space_operations z_erofs_aops;
  249. /*
  250. * Logical to physical block mapping
  251. *
  252. * Different with other file systems, it is used for 2 access modes:
  253. *
  254. * 1) RAW access mode:
  255. *
  256. * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
  257. * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
  258. *
  259. * Note that m_lblk in the RAW access mode refers to the number of
  260. * the compressed ondisk block rather than the uncompressed
  261. * in-memory block for the compressed file.
  262. *
  263. * m_pofs equals to m_lofs except for the inline data page.
  264. *
  265. * 2) Normal access mode:
  266. *
  267. * If the inode is not compressed, it has no difference with
  268. * the RAW access mode. However, if the inode is compressed,
  269. * users should pass a valid (m_lblk, m_lofs) pair, and get
  270. * the needed m_pblk, m_pofs, m_len to get the compressed data
  271. * and the updated m_lblk, m_lofs which indicates the start
  272. * of the corresponding uncompressed data in the file.
  273. */
  274. enum {
  275. BH_Zipped = BH_PrivateStart,
  276. BH_FullMapped,
  277. };
  278. /* Has a disk mapping */
  279. #define EROFS_MAP_MAPPED (1 << BH_Mapped)
  280. /* Located in metadata (could be copied from bd_inode) */
  281. #define EROFS_MAP_META (1 << BH_Meta)
  282. /* The extent has been compressed */
  283. #define EROFS_MAP_ZIPPED (1 << BH_Zipped)
  284. /* The length of extent is full */
  285. #define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped)
  286. struct erofs_map_blocks {
  287. erofs_off_t m_pa, m_la;
  288. u64 m_plen, m_llen;
  289. unsigned int m_flags;
  290. struct page *mpage;
  291. };
  292. /* Flags used by erofs_map_blocks_flatmode() */
  293. #define EROFS_GET_BLOCKS_RAW 0x0001
  294. /* zmap.c */
  295. #ifdef CONFIG_EROFS_FS_ZIP
  296. int z_erofs_fill_inode(struct inode *inode);
  297. int z_erofs_map_blocks_iter(struct inode *inode,
  298. struct erofs_map_blocks *map,
  299. int flags);
  300. #else
  301. static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
  302. static inline int z_erofs_map_blocks_iter(struct inode *inode,
  303. struct erofs_map_blocks *map,
  304. int flags)
  305. {
  306. return -EOPNOTSUPP;
  307. }
  308. #endif /* !CONFIG_EROFS_FS_ZIP */
  309. /* data.c */
  310. struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
  311. /* inode.c */
  312. static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
  313. {
  314. #if BITS_PER_LONG == 32
  315. return (nid >> 32) ^ (nid & 0xffffffff);
  316. #else
  317. return nid;
  318. #endif
  319. }
  320. extern const struct inode_operations erofs_generic_iops;
  321. extern const struct inode_operations erofs_symlink_iops;
  322. extern const struct inode_operations erofs_fast_symlink_iops;
  323. struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
  324. int erofs_getattr(const struct path *path, struct kstat *stat,
  325. u32 request_mask, unsigned int query_flags);
  326. /* namei.c */
  327. extern const struct inode_operations erofs_dir_iops;
  328. int erofs_namei(struct inode *dir, struct qstr *name,
  329. erofs_nid_t *nid, unsigned int *d_type);
  330. /* dir.c */
  331. extern const struct file_operations erofs_dir_fops;
  332. static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
  333. {
  334. int retried = 0;
  335. while (1) {
  336. void *p = vm_map_ram(pages, count, -1);
  337. /* retry two more times (totally 3 times) */
  338. if (p || ++retried >= 3)
  339. return p;
  340. vm_unmap_aliases();
  341. }
  342. return NULL;
  343. }
  344. /* pcpubuf.c */
  345. void *erofs_get_pcpubuf(unsigned int requiredpages);
  346. void erofs_put_pcpubuf(void *ptr);
  347. int erofs_pcpubuf_growsize(unsigned int nrpages);
  348. void erofs_pcpubuf_init(void);
  349. void erofs_pcpubuf_exit(void);
  350. /* utils.c / zdata.c */
  351. struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
  352. #ifdef CONFIG_EROFS_FS_ZIP
  353. int erofs_workgroup_put(struct erofs_workgroup *grp);
  354. struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
  355. pgoff_t index);
  356. struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
  357. struct erofs_workgroup *grp);
  358. void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
  359. void erofs_shrinker_register(struct super_block *sb);
  360. void erofs_shrinker_unregister(struct super_block *sb);
  361. int __init erofs_init_shrinker(void);
  362. void erofs_exit_shrinker(void);
  363. int __init z_erofs_init_zip_subsystem(void);
  364. void z_erofs_exit_zip_subsystem(void);
  365. int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
  366. struct erofs_workgroup *egrp);
  367. int erofs_try_to_free_cached_page(struct address_space *mapping,
  368. struct page *page);
  369. int z_erofs_load_lz4_config(struct super_block *sb,
  370. struct erofs_super_block *dsb,
  371. struct z_erofs_lz4_cfgs *lz4, int len);
  372. #else
  373. static inline void erofs_shrinker_register(struct super_block *sb) {}
  374. static inline void erofs_shrinker_unregister(struct super_block *sb) {}
  375. static inline int erofs_init_shrinker(void) { return 0; }
  376. static inline void erofs_exit_shrinker(void) {}
  377. static inline int z_erofs_init_zip_subsystem(void) { return 0; }
  378. static inline void z_erofs_exit_zip_subsystem(void) {}
  379. static inline int z_erofs_load_lz4_config(struct super_block *sb,
  380. struct erofs_super_block *dsb,
  381. struct z_erofs_lz4_cfgs *lz4, int len)
  382. {
  383. if (lz4 || dsb->u1.lz4_max_distance) {
  384. erofs_err(sb, "lz4 algorithm isn't enabled");
  385. return -EINVAL;
  386. }
  387. return 0;
  388. }
  389. #endif /* !CONFIG_EROFS_FS_ZIP */
  390. #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */
  391. #endif /* __EROFS_INTERNAL_H */