1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2017-2018 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 * Copyright (C) 2021, Alibaba Cloud 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 <linux/iomap.h> 20 #include "erofs_fs.h" 21 22 /* redefine pr_fmt "erofs: " */ 23 #undef pr_fmt 24 #define pr_fmt(fmt) "erofs: " fmt 25 26 __printf(3, 4) void _erofs_err(struct super_block *sb, 27 const char *function, const char *fmt, ...); 28 #define erofs_err(sb, fmt, ...) \ 29 _erofs_err(sb, __func__, fmt "\n", ##__VA_ARGS__) 30 __printf(3, 4) void _erofs_info(struct super_block *sb, 31 const char *function, const char *fmt, ...); 32 #define erofs_info(sb, fmt, ...) \ 33 _erofs_info(sb, __func__, fmt "\n", ##__VA_ARGS__) 34 #ifdef CONFIG_EROFS_FS_DEBUG 35 #define erofs_dbg(x, ...) pr_debug(x "\n", ##__VA_ARGS__) 36 #define DBG_BUGON BUG_ON 37 #else 38 #define erofs_dbg(x, ...) ((void)0) 39 #define DBG_BUGON(x) ((void)(x)) 40 #endif /* !CONFIG_EROFS_FS_DEBUG */ 41 42 /* EROFS_SUPER_MAGIC_V1 to represent the whole file system */ 43 #define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1 44 45 typedef u64 erofs_nid_t; 46 typedef u64 erofs_off_t; 47 /* data type for filesystem-wide blocks number */ 48 typedef u32 erofs_blk_t; 49 50 struct erofs_fs_context { 51 #ifdef CONFIG_EROFS_FS_ZIP 52 /* current strategy of how to use managed cache */ 53 unsigned char cache_strategy; 54 /* strategy of sync decompression (false - auto, true - force on) */ 55 bool readahead_sync_decompress; 56 57 /* threshold for decompression synchronously */ 58 unsigned int max_sync_decompress_pages; 59 #endif 60 unsigned int mount_opt; 61 }; 62 63 /* all filesystem-wide lz4 configurations */ 64 struct erofs_sb_lz4_info { 65 /* # of pages needed for EROFS lz4 rolling decompression */ 66 u16 max_distance_pages; 67 /* maximum possible blocks for pclusters in the filesystem */ 68 u16 max_pclusterblks; 69 }; 70 71 struct erofs_sb_info { 72 #ifdef CONFIG_EROFS_FS_ZIP 73 /* list for all registered superblocks, mainly for shrinker */ 74 struct list_head list; 75 struct mutex umount_mutex; 76 77 /* managed XArray arranged in physical block number */ 78 struct xarray managed_pslots; 79 80 unsigned int shrinker_run_no; 81 u16 available_compr_algs; 82 83 /* pseudo inode to manage cached pages */ 84 struct inode *managed_cache; 85 86 struct erofs_sb_lz4_info lz4; 87 #endif /* CONFIG_EROFS_FS_ZIP */ 88 struct dax_device *dax_dev; 89 u32 blocks; 90 u32 meta_blkaddr; 91 #ifdef CONFIG_EROFS_FS_XATTR 92 u32 xattr_blkaddr; 93 #endif 94 95 /* inode slot unit size in bit shift */ 96 unsigned char islotbits; 97 98 u32 sb_size; /* total superblock size */ 99 u32 build_time_nsec; 100 u64 build_time; 101 102 /* what we really care is nid, rather than ino.. */ 103 erofs_nid_t root_nid; 104 /* used for statfs, f_files - f_favail */ 105 u64 inos; 106 107 u8 uuid[16]; /* 128-bit uuid for volume */ 108 u8 volume_name[16]; /* volume name */ 109 u32 feature_compat; 110 u32 feature_incompat; 111 112 struct erofs_fs_context ctx; /* options */ 113 }; 114 115 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info) 116 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info) 117 118 /* Mount flags set via mount options or defaults */ 119 #define EROFS_MOUNT_XATTR_USER 0x00000010 120 #define EROFS_MOUNT_POSIX_ACL 0x00000020 121 #define EROFS_MOUNT_DAX_ALWAYS 0x00000040 122 #define EROFS_MOUNT_DAX_NEVER 0x00000080 123 124 #define clear_opt(ctx, option) ((ctx)->mount_opt &= ~EROFS_MOUNT_##option) 125 #define set_opt(ctx, option) ((ctx)->mount_opt |= EROFS_MOUNT_##option) 126 #define test_opt(ctx, option) ((ctx)->mount_opt & EROFS_MOUNT_##option) 127 128 enum { 129 EROFS_ZIP_CACHE_DISABLED, 130 EROFS_ZIP_CACHE_READAHEAD, 131 EROFS_ZIP_CACHE_READAROUND 132 }; 133 134 #ifdef CONFIG_EROFS_FS_ZIP 135 #define EROFS_LOCKED_MAGIC (INT_MIN | 0xE0F510CCL) 136 137 /* basic unit of the workstation of a super_block */ 138 struct erofs_workgroup { 139 /* the workgroup index in the workstation */ 140 pgoff_t index; 141 142 /* overall workgroup reference count */ 143 atomic_t refcount; 144 }; 145 146 #if defined(CONFIG_SMP) 147 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp, 148 int val) 149 { 150 preempt_disable(); 151 if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) { 152 preempt_enable(); 153 return false; 154 } 155 return true; 156 } 157 158 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp, 159 int orig_val) 160 { 161 /* 162 * other observers should notice all modifications 163 * in the freezing period. 164 */ 165 smp_mb(); 166 atomic_set(&grp->refcount, orig_val); 167 preempt_enable(); 168 } 169 170 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp) 171 { 172 return atomic_cond_read_relaxed(&grp->refcount, 173 VAL != EROFS_LOCKED_MAGIC); 174 } 175 #else 176 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp, 177 int val) 178 { 179 preempt_disable(); 180 /* no need to spin on UP platforms, let's just disable preemption. */ 181 if (val != atomic_read(&grp->refcount)) { 182 preempt_enable(); 183 return false; 184 } 185 return true; 186 } 187 188 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp, 189 int orig_val) 190 { 191 preempt_enable(); 192 } 193 194 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp) 195 { 196 int v = atomic_read(&grp->refcount); 197 198 /* workgroup is never freezed on uniprocessor systems */ 199 DBG_BUGON(v == EROFS_LOCKED_MAGIC); 200 return v; 201 } 202 #endif /* !CONFIG_SMP */ 203 #endif /* !CONFIG_EROFS_FS_ZIP */ 204 205 /* we strictly follow PAGE_SIZE and no buffer head yet */ 206 #define LOG_BLOCK_SIZE PAGE_SHIFT 207 208 #undef LOG_SECTORS_PER_BLOCK 209 #define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9) 210 211 #undef SECTORS_PER_BLOCK 212 #define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK) 213 214 #define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE) 215 216 #if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ) 217 #error erofs cannot be used in this platform 218 #endif 219 220 #define ROOT_NID(sb) ((sb)->root_nid) 221 222 #define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ) 223 #define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ) 224 #define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ) 225 226 static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid) 227 { 228 return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits); 229 } 230 231 #define EROFS_FEATURE_FUNCS(name, compat, feature) \ 232 static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \ 233 { \ 234 return sbi->feature_##compat & EROFS_FEATURE_##feature; \ 235 } 236 237 EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING) 238 EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS) 239 EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER) 240 EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM) 241 242 /* atomic flag definitions */ 243 #define EROFS_I_EA_INITED_BIT 0 244 #define EROFS_I_Z_INITED_BIT 1 245 246 /* bitlock definitions (arranged in reverse order) */ 247 #define EROFS_I_BL_XATTR_BIT (BITS_PER_LONG - 1) 248 #define EROFS_I_BL_Z_BIT (BITS_PER_LONG - 2) 249 250 struct erofs_inode { 251 erofs_nid_t nid; 252 253 /* atomic flags (including bitlocks) */ 254 unsigned long flags; 255 256 unsigned char datalayout; 257 unsigned char inode_isize; 258 unsigned short xattr_isize; 259 260 unsigned int xattr_shared_count; 261 unsigned int *xattr_shared_xattrs; 262 263 union { 264 erofs_blk_t raw_blkaddr; 265 struct { 266 unsigned short chunkformat; 267 unsigned char chunkbits; 268 }; 269 #ifdef CONFIG_EROFS_FS_ZIP 270 struct { 271 unsigned short z_advise; 272 unsigned char z_algorithmtype[2]; 273 unsigned char z_logical_clusterbits; 274 }; 275 #endif /* CONFIG_EROFS_FS_ZIP */ 276 }; 277 /* the corresponding vfs inode */ 278 struct inode vfs_inode; 279 }; 280 281 #define EROFS_I(ptr) \ 282 container_of(ptr, struct erofs_inode, vfs_inode) 283 284 static inline unsigned long erofs_inode_datablocks(struct inode *inode) 285 { 286 /* since i_size cannot be changed */ 287 return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ); 288 } 289 290 static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit, 291 unsigned int bits) 292 { 293 294 return (value >> bit) & ((1 << bits) - 1); 295 } 296 297 298 static inline unsigned int erofs_inode_version(unsigned int value) 299 { 300 return erofs_bitrange(value, EROFS_I_VERSION_BIT, 301 EROFS_I_VERSION_BITS); 302 } 303 304 static inline unsigned int erofs_inode_datalayout(unsigned int value) 305 { 306 return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT, 307 EROFS_I_DATALAYOUT_BITS); 308 } 309 310 extern const struct super_operations erofs_sops; 311 312 extern const struct address_space_operations erofs_raw_access_aops; 313 extern const struct address_space_operations z_erofs_aops; 314 315 /* 316 * Logical to physical block mapping 317 * 318 * Different with other file systems, it is used for 2 access modes: 319 * 320 * 1) RAW access mode: 321 * 322 * Users pass a valid (m_lblk, m_lofs -- usually 0) pair, 323 * and get the valid m_pblk, m_pofs and the longest m_len(in bytes). 324 * 325 * Note that m_lblk in the RAW access mode refers to the number of 326 * the compressed ondisk block rather than the uncompressed 327 * in-memory block for the compressed file. 328 * 329 * m_pofs equals to m_lofs except for the inline data page. 330 * 331 * 2) Normal access mode: 332 * 333 * If the inode is not compressed, it has no difference with 334 * the RAW access mode. However, if the inode is compressed, 335 * users should pass a valid (m_lblk, m_lofs) pair, and get 336 * the needed m_pblk, m_pofs, m_len to get the compressed data 337 * and the updated m_lblk, m_lofs which indicates the start 338 * of the corresponding uncompressed data in the file. 339 */ 340 enum { 341 BH_Zipped = BH_PrivateStart, 342 BH_FullMapped, 343 }; 344 345 /* Has a disk mapping */ 346 #define EROFS_MAP_MAPPED (1 << BH_Mapped) 347 /* Located in metadata (could be copied from bd_inode) */ 348 #define EROFS_MAP_META (1 << BH_Meta) 349 /* The extent has been compressed */ 350 #define EROFS_MAP_ZIPPED (1 << BH_Zipped) 351 /* The length of extent is full */ 352 #define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped) 353 354 struct erofs_map_blocks { 355 erofs_off_t m_pa, m_la; 356 u64 m_plen, m_llen; 357 358 unsigned int m_flags; 359 360 struct page *mpage; 361 }; 362 363 /* Flags used by erofs_map_blocks_flatmode() */ 364 #define EROFS_GET_BLOCKS_RAW 0x0001 365 /* 366 * Used to get the exact decompressed length, e.g. fiemap (consider lookback 367 * approach instead if possible since it's more metadata lightweight.) 368 */ 369 #define EROFS_GET_BLOCKS_FIEMAP 0x0002 370 371 /* zmap.c */ 372 extern const struct iomap_ops z_erofs_iomap_report_ops; 373 374 #ifdef CONFIG_EROFS_FS_ZIP 375 int z_erofs_fill_inode(struct inode *inode); 376 int z_erofs_map_blocks_iter(struct inode *inode, 377 struct erofs_map_blocks *map, 378 int flags); 379 #else 380 static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; } 381 static inline int z_erofs_map_blocks_iter(struct inode *inode, 382 struct erofs_map_blocks *map, 383 int flags) 384 { 385 return -EOPNOTSUPP; 386 } 387 #endif /* !CONFIG_EROFS_FS_ZIP */ 388 389 /* data.c */ 390 extern const struct file_operations erofs_file_fops; 391 struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr); 392 int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 393 u64 start, u64 len); 394 395 /* inode.c */ 396 static inline unsigned long erofs_inode_hash(erofs_nid_t nid) 397 { 398 #if BITS_PER_LONG == 32 399 return (nid >> 32) ^ (nid & 0xffffffff); 400 #else 401 return nid; 402 #endif 403 } 404 405 extern const struct inode_operations erofs_generic_iops; 406 extern const struct inode_operations erofs_symlink_iops; 407 extern const struct inode_operations erofs_fast_symlink_iops; 408 409 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir); 410 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path, 411 struct kstat *stat, u32 request_mask, 412 unsigned int query_flags); 413 414 /* namei.c */ 415 extern const struct inode_operations erofs_dir_iops; 416 417 int erofs_namei(struct inode *dir, struct qstr *name, 418 erofs_nid_t *nid, unsigned int *d_type); 419 420 /* dir.c */ 421 extern const struct file_operations erofs_dir_fops; 422 423 static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count) 424 { 425 int retried = 0; 426 427 while (1) { 428 void *p = vm_map_ram(pages, count, -1); 429 430 /* retry two more times (totally 3 times) */ 431 if (p || ++retried >= 3) 432 return p; 433 vm_unmap_aliases(); 434 } 435 return NULL; 436 } 437 438 /* pcpubuf.c */ 439 void *erofs_get_pcpubuf(unsigned int requiredpages); 440 void erofs_put_pcpubuf(void *ptr); 441 int erofs_pcpubuf_growsize(unsigned int nrpages); 442 void erofs_pcpubuf_init(void); 443 void erofs_pcpubuf_exit(void); 444 445 /* utils.c / zdata.c */ 446 struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp); 447 448 #ifdef CONFIG_EROFS_FS_ZIP 449 int erofs_workgroup_put(struct erofs_workgroup *grp); 450 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb, 451 pgoff_t index); 452 struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb, 453 struct erofs_workgroup *grp); 454 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp); 455 void erofs_shrinker_register(struct super_block *sb); 456 void erofs_shrinker_unregister(struct super_block *sb); 457 int __init erofs_init_shrinker(void); 458 void erofs_exit_shrinker(void); 459 int __init z_erofs_init_zip_subsystem(void); 460 void z_erofs_exit_zip_subsystem(void); 461 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 462 struct erofs_workgroup *egrp); 463 int erofs_try_to_free_cached_page(struct page *page); 464 int z_erofs_load_lz4_config(struct super_block *sb, 465 struct erofs_super_block *dsb, 466 struct z_erofs_lz4_cfgs *lz4, int len); 467 #else 468 static inline void erofs_shrinker_register(struct super_block *sb) {} 469 static inline void erofs_shrinker_unregister(struct super_block *sb) {} 470 static inline int erofs_init_shrinker(void) { return 0; } 471 static inline void erofs_exit_shrinker(void) {} 472 static inline int z_erofs_init_zip_subsystem(void) { return 0; } 473 static inline void z_erofs_exit_zip_subsystem(void) {} 474 static inline int z_erofs_load_lz4_config(struct super_block *sb, 475 struct erofs_super_block *dsb, 476 struct z_erofs_lz4_cfgs *lz4, int len) 477 { 478 if (lz4 || dsb->u1.lz4_max_distance) { 479 erofs_err(sb, "lz4 algorithm isn't enabled"); 480 return -EINVAL; 481 } 482 return 0; 483 } 484 #endif /* !CONFIG_EROFS_FS_ZIP */ 485 486 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */ 487 488 #endif /* __EROFS_INTERNAL_H */ 489