1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2017-2018 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 */ 6 #ifndef __EROFS_INTERNAL_H 7 #define __EROFS_INTERNAL_H 8 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 20 /* redefine pr_fmt "erofs: " */ 21 #undef pr_fmt 22 #define pr_fmt(fmt) "erofs: " fmt 23 24 __printf(3, 4) void _erofs_err(struct super_block *sb, 25 const char *function, const char *fmt, ...); 26 #define erofs_err(sb, fmt, ...) \ 27 _erofs_err(sb, __func__, fmt "\n", ##__VA_ARGS__) 28 __printf(3, 4) void _erofs_info(struct super_block *sb, 29 const char *function, const char *fmt, ...); 30 #define erofs_info(sb, fmt, ...) \ 31 _erofs_info(sb, __func__, fmt "\n", ##__VA_ARGS__) 32 #ifdef CONFIG_EROFS_FS_DEBUG 33 #define erofs_dbg(x, ...) pr_debug(x "\n", ##__VA_ARGS__) 34 #define DBG_BUGON BUG_ON 35 #else 36 #define erofs_dbg(x, ...) ((void)0) 37 #define DBG_BUGON(x) ((void)(x)) 38 #endif /* !CONFIG_EROFS_FS_DEBUG */ 39 40 /* EROFS_SUPER_MAGIC_V1 to represent the whole file system */ 41 #define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1 42 43 typedef u64 erofs_nid_t; 44 typedef u64 erofs_off_t; 45 /* data type for filesystem-wide blocks number */ 46 typedef u32 erofs_blk_t; 47 48 struct erofs_fs_context { 49 #ifdef CONFIG_EROFS_FS_ZIP 50 /* current strategy of how to use managed cache */ 51 unsigned char cache_strategy; 52 /* strategy of sync decompression (false - auto, true - force on) */ 53 bool readahead_sync_decompress; 54 55 /* threshold for decompression synchronously */ 56 unsigned int max_sync_decompress_pages; 57 #endif 58 unsigned int mount_opt; 59 }; 60 61 /* all filesystem-wide lz4 configurations */ 62 struct erofs_sb_lz4_info { 63 /* # of pages needed for EROFS lz4 rolling decompression */ 64 u16 max_distance_pages; 65 /* maximum possible blocks for pclusters in the filesystem */ 66 u16 max_pclusterblks; 67 }; 68 69 struct erofs_sb_info { 70 #ifdef CONFIG_EROFS_FS_ZIP 71 /* list for all registered superblocks, mainly for shrinker */ 72 struct list_head list; 73 struct mutex umount_mutex; 74 75 /* managed XArray arranged in physical block number */ 76 struct xarray managed_pslots; 77 78 unsigned int shrinker_run_no; 79 u16 available_compr_algs; 80 81 /* pseudo inode to manage cached pages */ 82 struct inode *managed_cache; 83 84 struct erofs_sb_lz4_info lz4; 85 #endif /* CONFIG_EROFS_FS_ZIP */ 86 u32 blocks; 87 u32 meta_blkaddr; 88 #ifdef CONFIG_EROFS_FS_XATTR 89 u32 xattr_blkaddr; 90 #endif 91 92 /* inode slot unit size in bit shift */ 93 unsigned char islotbits; 94 95 u32 sb_size; /* total superblock size */ 96 u32 build_time_nsec; 97 u64 build_time; 98 99 /* what we really care is nid, rather than ino.. */ 100 erofs_nid_t root_nid; 101 /* used for statfs, f_files - f_favail */ 102 u64 inos; 103 104 u8 uuid[16]; /* 128-bit uuid for volume */ 105 u8 volume_name[16]; /* volume name */ 106 u32 feature_compat; 107 u32 feature_incompat; 108 109 struct erofs_fs_context ctx; /* options */ 110 }; 111 112 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info) 113 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info) 114 115 /* Mount flags set via mount options or defaults */ 116 #define EROFS_MOUNT_XATTR_USER 0x00000010 117 #define EROFS_MOUNT_POSIX_ACL 0x00000020 118 119 #define clear_opt(ctx, option) ((ctx)->mount_opt &= ~EROFS_MOUNT_##option) 120 #define set_opt(ctx, option) ((ctx)->mount_opt |= EROFS_MOUNT_##option) 121 #define test_opt(ctx, option) ((ctx)->mount_opt & EROFS_MOUNT_##option) 122 123 enum { 124 EROFS_ZIP_CACHE_DISABLED, 125 EROFS_ZIP_CACHE_READAHEAD, 126 EROFS_ZIP_CACHE_READAROUND 127 }; 128 129 #ifdef CONFIG_EROFS_FS_ZIP 130 #define EROFS_LOCKED_MAGIC (INT_MIN | 0xE0F510CCL) 131 132 /* basic unit of the workstation of a super_block */ 133 struct erofs_workgroup { 134 /* the workgroup index in the workstation */ 135 pgoff_t index; 136 137 /* overall workgroup reference count */ 138 atomic_t refcount; 139 }; 140 141 #if defined(CONFIG_SMP) 142 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp, 143 int val) 144 { 145 preempt_disable(); 146 if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) { 147 preempt_enable(); 148 return false; 149 } 150 return true; 151 } 152 153 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp, 154 int orig_val) 155 { 156 /* 157 * other observers should notice all modifications 158 * in the freezing period. 159 */ 160 smp_mb(); 161 atomic_set(&grp->refcount, orig_val); 162 preempt_enable(); 163 } 164 165 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp) 166 { 167 return atomic_cond_read_relaxed(&grp->refcount, 168 VAL != EROFS_LOCKED_MAGIC); 169 } 170 #else 171 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp, 172 int val) 173 { 174 preempt_disable(); 175 /* no need to spin on UP platforms, let's just disable preemption. */ 176 if (val != atomic_read(&grp->refcount)) { 177 preempt_enable(); 178 return false; 179 } 180 return true; 181 } 182 183 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp, 184 int orig_val) 185 { 186 preempt_enable(); 187 } 188 189 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp) 190 { 191 int v = atomic_read(&grp->refcount); 192 193 /* workgroup is never freezed on uniprocessor systems */ 194 DBG_BUGON(v == EROFS_LOCKED_MAGIC); 195 return v; 196 } 197 #endif /* !CONFIG_SMP */ 198 #endif /* !CONFIG_EROFS_FS_ZIP */ 199 200 /* we strictly follow PAGE_SIZE and no buffer head yet */ 201 #define LOG_BLOCK_SIZE PAGE_SHIFT 202 203 #undef LOG_SECTORS_PER_BLOCK 204 #define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9) 205 206 #undef SECTORS_PER_BLOCK 207 #define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK) 208 209 #define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE) 210 211 #if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ) 212 #error erofs cannot be used in this platform 213 #endif 214 215 #define ROOT_NID(sb) ((sb)->root_nid) 216 217 #define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ) 218 #define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ) 219 #define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ) 220 221 static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid) 222 { 223 return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits); 224 } 225 226 #define EROFS_FEATURE_FUNCS(name, compat, feature) \ 227 static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \ 228 { \ 229 return sbi->feature_##compat & EROFS_FEATURE_##feature; \ 230 } 231 232 EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING) 233 EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS) 234 EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER) 235 EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM) 236 237 /* atomic flag definitions */ 238 #define EROFS_I_EA_INITED_BIT 0 239 #define EROFS_I_Z_INITED_BIT 1 240 241 /* bitlock definitions (arranged in reverse order) */ 242 #define EROFS_I_BL_XATTR_BIT (BITS_PER_LONG - 1) 243 #define EROFS_I_BL_Z_BIT (BITS_PER_LONG - 2) 244 245 struct erofs_inode { 246 erofs_nid_t nid; 247 248 /* atomic flags (including bitlocks) */ 249 unsigned long flags; 250 251 unsigned char datalayout; 252 unsigned char inode_isize; 253 unsigned short xattr_isize; 254 255 unsigned int xattr_shared_count; 256 unsigned int *xattr_shared_xattrs; 257 258 union { 259 erofs_blk_t raw_blkaddr; 260 #ifdef CONFIG_EROFS_FS_ZIP 261 struct { 262 unsigned short z_advise; 263 unsigned char z_algorithmtype[2]; 264 unsigned char z_logical_clusterbits; 265 }; 266 #endif /* CONFIG_EROFS_FS_ZIP */ 267 }; 268 /* the corresponding vfs inode */ 269 struct inode vfs_inode; 270 }; 271 272 #define EROFS_I(ptr) \ 273 container_of(ptr, struct erofs_inode, vfs_inode) 274 275 static inline unsigned long erofs_inode_datablocks(struct inode *inode) 276 { 277 /* since i_size cannot be changed */ 278 return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ); 279 } 280 281 static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit, 282 unsigned int bits) 283 { 284 285 return (value >> bit) & ((1 << bits) - 1); 286 } 287 288 289 static inline unsigned int erofs_inode_version(unsigned int value) 290 { 291 return erofs_bitrange(value, EROFS_I_VERSION_BIT, 292 EROFS_I_VERSION_BITS); 293 } 294 295 static inline unsigned int erofs_inode_datalayout(unsigned int value) 296 { 297 return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT, 298 EROFS_I_DATALAYOUT_BITS); 299 } 300 301 extern const struct super_operations erofs_sops; 302 303 extern const struct address_space_operations erofs_raw_access_aops; 304 extern const struct address_space_operations z_erofs_aops; 305 306 /* 307 * Logical to physical block mapping 308 * 309 * Different with other file systems, it is used for 2 access modes: 310 * 311 * 1) RAW access mode: 312 * 313 * Users pass a valid (m_lblk, m_lofs -- usually 0) pair, 314 * and get the valid m_pblk, m_pofs and the longest m_len(in bytes). 315 * 316 * Note that m_lblk in the RAW access mode refers to the number of 317 * the compressed ondisk block rather than the uncompressed 318 * in-memory block for the compressed file. 319 * 320 * m_pofs equals to m_lofs except for the inline data page. 321 * 322 * 2) Normal access mode: 323 * 324 * If the inode is not compressed, it has no difference with 325 * the RAW access mode. However, if the inode is compressed, 326 * users should pass a valid (m_lblk, m_lofs) pair, and get 327 * the needed m_pblk, m_pofs, m_len to get the compressed data 328 * and the updated m_lblk, m_lofs which indicates the start 329 * of the corresponding uncompressed data in the file. 330 */ 331 enum { 332 BH_Zipped = BH_PrivateStart, 333 BH_FullMapped, 334 }; 335 336 /* Has a disk mapping */ 337 #define EROFS_MAP_MAPPED (1 << BH_Mapped) 338 /* Located in metadata (could be copied from bd_inode) */ 339 #define EROFS_MAP_META (1 << BH_Meta) 340 /* The extent has been compressed */ 341 #define EROFS_MAP_ZIPPED (1 << BH_Zipped) 342 /* The length of extent is full */ 343 #define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped) 344 345 struct erofs_map_blocks { 346 erofs_off_t m_pa, m_la; 347 u64 m_plen, m_llen; 348 349 unsigned int m_flags; 350 351 struct page *mpage; 352 }; 353 354 /* Flags used by erofs_map_blocks_flatmode() */ 355 #define EROFS_GET_BLOCKS_RAW 0x0001 356 357 /* zmap.c */ 358 #ifdef CONFIG_EROFS_FS_ZIP 359 int z_erofs_fill_inode(struct inode *inode); 360 int z_erofs_map_blocks_iter(struct inode *inode, 361 struct erofs_map_blocks *map, 362 int flags); 363 #else 364 static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; } 365 static inline int z_erofs_map_blocks_iter(struct inode *inode, 366 struct erofs_map_blocks *map, 367 int flags) 368 { 369 return -EOPNOTSUPP; 370 } 371 #endif /* !CONFIG_EROFS_FS_ZIP */ 372 373 /* data.c */ 374 struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr); 375 376 /* inode.c */ 377 static inline unsigned long erofs_inode_hash(erofs_nid_t nid) 378 { 379 #if BITS_PER_LONG == 32 380 return (nid >> 32) ^ (nid & 0xffffffff); 381 #else 382 return nid; 383 #endif 384 } 385 386 extern const struct inode_operations erofs_generic_iops; 387 extern const struct inode_operations erofs_symlink_iops; 388 extern const struct inode_operations erofs_fast_symlink_iops; 389 390 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir); 391 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path, 392 struct kstat *stat, u32 request_mask, 393 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; 403 404 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 450 static inline void erofs_shrinker_register(struct super_block *sb) {} 451 static inline void erofs_shrinker_unregister(struct super_block *sb) {} 452 static inline int erofs_init_shrinker(void) { return 0; } 453 static inline void erofs_exit_shrinker(void) {} 454 static inline int z_erofs_init_zip_subsystem(void) { return 0; } 455 static inline void z_erofs_exit_zip_subsystem(void) {} 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