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 44typedef u64 erofs_nid_t; 45typedef u64 erofs_off_t; 46/* data type for filesystem-wide blocks number */ 47typedef u32 erofs_blk_t; 48 49struct 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 60struct 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 110enum { 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 */ 120struct 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) 129static 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 140static 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 152static 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 158static 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 170static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp, 171 int orig_val) 172{ 173 preempt_enable(); 174} 175 176static 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 214static 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 227struct 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 int 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 258static 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 264static 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 272static 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 278static 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 284extern const struct super_operations erofs_sops; 285 286extern const struct address_space_operations erofs_raw_access_aops; 287extern 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 */ 314enum { 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 328struct 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 342int z_erofs_fill_inode(struct inode *inode); 343int z_erofs_map_blocks_iter(struct inode *inode, 344 struct erofs_map_blocks *map, 345 int flags); 346#else 347static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; } 348static 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 */ 357struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr); 358 359int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int); 360 361/* inode.c */ 362static 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 371extern const struct inode_operations erofs_generic_iops; 372extern const struct inode_operations erofs_symlink_iops; 373extern const struct inode_operations erofs_fast_symlink_iops; 374 375struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir); 376int erofs_getattr(const struct path *path, struct kstat *stat, 377 u32 request_mask, unsigned int query_flags); 378 379/* namei.c */ 380extern const struct inode_operations erofs_dir_iops; 381 382int erofs_namei(struct inode *dir, struct qstr *name, 383 erofs_nid_t *nid, unsigned int *d_type); 384 385/* dir.c */ 386extern const struct file_operations erofs_dir_fops; 387 388/* utils.c / zdata.c */ 389struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp); 390 391#if (EROFS_PCPUBUF_NR_PAGES > 0) 392void *erofs_get_pcpubuf(unsigned int pagenr); 393#define erofs_put_pcpubuf(buf) do { \ 394 (void)&(buf); \ 395 preempt_enable(); \ 396} while (0) 397#else 398static 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 407int erofs_workgroup_put(struct erofs_workgroup *grp); 408struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb, 409 pgoff_t index); 410struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb, 411 struct erofs_workgroup *grp); 412void erofs_workgroup_free_rcu(struct erofs_workgroup *grp); 413void erofs_shrinker_register(struct super_block *sb); 414void erofs_shrinker_unregister(struct super_block *sb); 415int __init erofs_init_shrinker(void); 416void erofs_exit_shrinker(void); 417int __init z_erofs_init_zip_subsystem(void); 418void z_erofs_exit_zip_subsystem(void); 419int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 420 struct erofs_workgroup *egrp); 421int erofs_try_to_free_cached_page(struct address_space *mapping, 422 struct page *page); 423#else 424static inline void erofs_shrinker_register(struct super_block *sb) {} 425static inline void erofs_shrinker_unregister(struct super_block *sb) {} 426static inline int erofs_init_shrinker(void) { return 0; } 427static inline void erofs_exit_shrinker(void) {} 428static inline int z_erofs_init_zip_subsystem(void) { return 0; } 429static 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