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 /* strategy of sync decompression (false - auto, true - force on) */ 54 bool readahead_sync_decompress; 55 56 /* threshold for decompression synchronously */ 57 unsigned int max_sync_decompress_pages; 58 #endif 59 unsigned int mount_opt; 60 }; 61 62 struct erofs_sb_info { 63 #ifdef CONFIG_EROFS_FS_ZIP 64 /* list for all registered superblocks, mainly for shrinker */ 65 struct list_head list; 66 struct mutex umount_mutex; 67 68 /* managed XArray arranged in physical block number */ 69 struct xarray managed_pslots; 70 71 unsigned int shrinker_run_no; 72 73 /* pseudo inode to manage cached pages */ 74 struct inode *managed_cache; 75 #endif /* CONFIG_EROFS_FS_ZIP */ 76 u32 blocks; 77 u32 meta_blkaddr; 78 #ifdef CONFIG_EROFS_FS_XATTR 79 u32 xattr_blkaddr; 80 #endif 81 82 /* inode slot unit size in bit shift */ 83 unsigned char islotbits; 84 85 u32 build_time_nsec; 86 u64 build_time; 87 88 /* what we really care is nid, rather than ino.. */ 89 erofs_nid_t root_nid; 90 /* used for statfs, f_files - f_favail */ 91 u64 inos; 92 93 u8 uuid[16]; /* 128-bit uuid for volume */ 94 u8 volume_name[16]; /* volume name */ 95 u32 feature_compat; 96 u32 feature_incompat; 97 98 struct erofs_fs_context ctx; /* options */ 99 }; 100 101 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info) 102 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info) 103 104 /* Mount flags set via mount options or defaults */ 105 #define EROFS_MOUNT_XATTR_USER 0x00000010 106 #define EROFS_MOUNT_POSIX_ACL 0x00000020 107 108 #define clear_opt(ctx, option) ((ctx)->mount_opt &= ~EROFS_MOUNT_##option) 109 #define set_opt(ctx, option) ((ctx)->mount_opt |= EROFS_MOUNT_##option) 110 #define test_opt(ctx, option) ((ctx)->mount_opt & EROFS_MOUNT_##option) 111 112 enum { 113 EROFS_ZIP_CACHE_DISABLED, 114 EROFS_ZIP_CACHE_READAHEAD, 115 EROFS_ZIP_CACHE_READAROUND 116 }; 117 118 #ifdef CONFIG_EROFS_FS_ZIP 119 #define EROFS_LOCKED_MAGIC (INT_MIN | 0xE0F510CCL) 120 121 /* basic unit of the workstation of a super_block */ 122 struct erofs_workgroup { 123 /* the workgroup index in the workstation */ 124 pgoff_t index; 125 126 /* overall workgroup reference count */ 127 atomic_t refcount; 128 }; 129 130 #if defined(CONFIG_SMP) 131 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp, 132 int val) 133 { 134 preempt_disable(); 135 if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) { 136 preempt_enable(); 137 return false; 138 } 139 return true; 140 } 141 142 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp, 143 int orig_val) 144 { 145 /* 146 * other observers should notice all modifications 147 * in the freezing period. 148 */ 149 smp_mb(); 150 atomic_set(&grp->refcount, orig_val); 151 preempt_enable(); 152 } 153 154 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp) 155 { 156 return atomic_cond_read_relaxed(&grp->refcount, 157 VAL != EROFS_LOCKED_MAGIC); 158 } 159 #else 160 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp, 161 int val) 162 { 163 preempt_disable(); 164 /* no need to spin on UP platforms, let's just disable preemption. */ 165 if (val != atomic_read(&grp->refcount)) { 166 preempt_enable(); 167 return false; 168 } 169 return true; 170 } 171 172 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp, 173 int orig_val) 174 { 175 preempt_enable(); 176 } 177 178 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp) 179 { 180 int v = atomic_read(&grp->refcount); 181 182 /* workgroup is never freezed on uniprocessor systems */ 183 DBG_BUGON(v == EROFS_LOCKED_MAGIC); 184 return v; 185 } 186 #endif /* !CONFIG_SMP */ 187 188 /* hard limit of pages per compressed cluster */ 189 #define Z_EROFS_CLUSTER_MAX_PAGES (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT) 190 #define EROFS_PCPUBUF_NR_PAGES Z_EROFS_CLUSTER_MAX_PAGES 191 #else 192 #define EROFS_PCPUBUF_NR_PAGES 0 193 #endif /* !CONFIG_EROFS_FS_ZIP */ 194 195 /* we strictly follow PAGE_SIZE and no buffer head yet */ 196 #define LOG_BLOCK_SIZE PAGE_SHIFT 197 198 #undef LOG_SECTORS_PER_BLOCK 199 #define LOG_SECTORS_PER_BLOCK (PAGE_SHIFT - 9) 200 201 #undef SECTORS_PER_BLOCK 202 #define SECTORS_PER_BLOCK (1 << SECTORS_PER_BLOCK) 203 204 #define EROFS_BLKSIZ (1 << LOG_BLOCK_SIZE) 205 206 #if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ) 207 #error erofs cannot be used in this platform 208 #endif 209 210 #define ROOT_NID(sb) ((sb)->root_nid) 211 212 #define erofs_blknr(addr) ((addr) / EROFS_BLKSIZ) 213 #define erofs_blkoff(addr) ((addr) % EROFS_BLKSIZ) 214 #define blknr_to_addr(nr) ((erofs_off_t)(nr) * EROFS_BLKSIZ) 215 216 static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid) 217 { 218 return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits); 219 } 220 221 /* atomic flag definitions */ 222 #define EROFS_I_EA_INITED_BIT 0 223 #define EROFS_I_Z_INITED_BIT 1 224 225 /* bitlock definitions (arranged in reverse order) */ 226 #define EROFS_I_BL_XATTR_BIT (BITS_PER_LONG - 1) 227 #define EROFS_I_BL_Z_BIT (BITS_PER_LONG - 2) 228 229 struct erofs_inode { 230 erofs_nid_t nid; 231 232 /* atomic flags (including bitlocks) */ 233 unsigned long flags; 234 235 unsigned char datalayout; 236 unsigned char inode_isize; 237 unsigned short xattr_isize; 238 239 unsigned int xattr_shared_count; 240 unsigned int *xattr_shared_xattrs; 241 242 union { 243 erofs_blk_t raw_blkaddr; 244 #ifdef CONFIG_EROFS_FS_ZIP 245 struct { 246 unsigned short z_advise; 247 unsigned char z_algorithmtype[2]; 248 unsigned char z_logical_clusterbits; 249 unsigned char z_physical_clusterbits[2]; 250 }; 251 #endif /* CONFIG_EROFS_FS_ZIP */ 252 }; 253 /* the corresponding vfs inode */ 254 struct inode vfs_inode; 255 }; 256 257 #define EROFS_I(ptr) \ 258 container_of(ptr, struct erofs_inode, vfs_inode) 259 260 static inline unsigned long erofs_inode_datablocks(struct inode *inode) 261 { 262 /* since i_size cannot be changed */ 263 return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ); 264 } 265 266 static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit, 267 unsigned int bits) 268 { 269 270 return (value >> bit) & ((1 << bits) - 1); 271 } 272 273 274 static inline unsigned int erofs_inode_version(unsigned int value) 275 { 276 return erofs_bitrange(value, EROFS_I_VERSION_BIT, 277 EROFS_I_VERSION_BITS); 278 } 279 280 static inline unsigned int erofs_inode_datalayout(unsigned int value) 281 { 282 return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT, 283 EROFS_I_DATALAYOUT_BITS); 284 } 285 286 extern const struct super_operations erofs_sops; 287 288 extern const struct address_space_operations erofs_raw_access_aops; 289 extern const struct address_space_operations z_erofs_aops; 290 291 /* 292 * Logical to physical block mapping, used by erofs_map_blocks() 293 * 294 * Different with other file systems, it is used for 2 access modes: 295 * 296 * 1) RAW access mode: 297 * 298 * Users pass a valid (m_lblk, m_lofs -- usually 0) pair, 299 * and get the valid m_pblk, m_pofs and the longest m_len(in bytes). 300 * 301 * Note that m_lblk in the RAW access mode refers to the number of 302 * the compressed ondisk block rather than the uncompressed 303 * in-memory block for the compressed file. 304 * 305 * m_pofs equals to m_lofs except for the inline data page. 306 * 307 * 2) Normal access mode: 308 * 309 * If the inode is not compressed, it has no difference with 310 * the RAW access mode. However, if the inode is compressed, 311 * users should pass a valid (m_lblk, m_lofs) pair, and get 312 * the needed m_pblk, m_pofs, m_len to get the compressed data 313 * and the updated m_lblk, m_lofs which indicates the start 314 * of the corresponding uncompressed data in the file. 315 */ 316 enum { 317 BH_Zipped = BH_PrivateStart, 318 BH_FullMapped, 319 }; 320 321 /* Has a disk mapping */ 322 #define EROFS_MAP_MAPPED (1 << BH_Mapped) 323 /* Located in metadata (could be copied from bd_inode) */ 324 #define EROFS_MAP_META (1 << BH_Meta) 325 /* The extent has been compressed */ 326 #define EROFS_MAP_ZIPPED (1 << BH_Zipped) 327 /* The length of extent is full */ 328 #define EROFS_MAP_FULL_MAPPED (1 << BH_FullMapped) 329 330 struct erofs_map_blocks { 331 erofs_off_t m_pa, m_la; 332 u64 m_plen, m_llen; 333 334 unsigned int m_flags; 335 336 struct page *mpage; 337 }; 338 339 /* Flags used by erofs_map_blocks() */ 340 #define EROFS_GET_BLOCKS_RAW 0x0001 341 342 /* zmap.c */ 343 #ifdef CONFIG_EROFS_FS_ZIP 344 int z_erofs_fill_inode(struct inode *inode); 345 int z_erofs_map_blocks_iter(struct inode *inode, 346 struct erofs_map_blocks *map, 347 int flags); 348 #else 349 static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; } 350 static inline int z_erofs_map_blocks_iter(struct inode *inode, 351 struct erofs_map_blocks *map, 352 int flags) 353 { 354 return -EOPNOTSUPP; 355 } 356 #endif /* !CONFIG_EROFS_FS_ZIP */ 357 358 /* data.c */ 359 struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr); 360 361 int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int); 362 363 /* inode.c */ 364 static inline unsigned long erofs_inode_hash(erofs_nid_t nid) 365 { 366 #if BITS_PER_LONG == 32 367 return (nid >> 32) ^ (nid & 0xffffffff); 368 #else 369 return nid; 370 #endif 371 } 372 373 extern const struct inode_operations erofs_generic_iops; 374 extern const struct inode_operations erofs_symlink_iops; 375 extern const struct inode_operations erofs_fast_symlink_iops; 376 377 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir); 378 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path, 379 struct kstat *stat, u32 request_mask, 380 unsigned int query_flags); 381 382 /* namei.c */ 383 extern const struct inode_operations erofs_dir_iops; 384 385 int erofs_namei(struct inode *dir, struct qstr *name, 386 erofs_nid_t *nid, unsigned int *d_type); 387 388 /* dir.c */ 389 extern const struct file_operations erofs_dir_fops; 390 391 /* utils.c / zdata.c */ 392 struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp); 393 394 #if (EROFS_PCPUBUF_NR_PAGES > 0) 395 void *erofs_get_pcpubuf(unsigned int pagenr); 396 #define erofs_put_pcpubuf(buf) do { \ 397 (void)&(buf); \ 398 preempt_enable(); \ 399 } while (0) 400 #else 401 static inline void *erofs_get_pcpubuf(unsigned int pagenr) 402 { 403 return ERR_PTR(-EOPNOTSUPP); 404 } 405 406 #define erofs_put_pcpubuf(buf) do {} while (0) 407 #endif 408 409 #ifdef CONFIG_EROFS_FS_ZIP 410 int erofs_workgroup_put(struct erofs_workgroup *grp); 411 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb, 412 pgoff_t index); 413 struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb, 414 struct erofs_workgroup *grp); 415 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp); 416 void erofs_shrinker_register(struct super_block *sb); 417 void erofs_shrinker_unregister(struct super_block *sb); 418 int __init erofs_init_shrinker(void); 419 void erofs_exit_shrinker(void); 420 int __init z_erofs_init_zip_subsystem(void); 421 void z_erofs_exit_zip_subsystem(void); 422 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 423 struct erofs_workgroup *egrp); 424 int erofs_try_to_free_cached_page(struct address_space *mapping, 425 struct page *page); 426 #else 427 static inline void erofs_shrinker_register(struct super_block *sb) {} 428 static inline void erofs_shrinker_unregister(struct super_block *sb) {} 429 static inline int erofs_init_shrinker(void) { return 0; } 430 static inline void erofs_exit_shrinker(void) {} 431 static inline int z_erofs_init_zip_subsystem(void) { return 0; } 432 static inline void z_erofs_exit_zip_subsystem(void) {} 433 #endif /* !CONFIG_EROFS_FS_ZIP */ 434 435 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */ 436 437 #endif /* __EROFS_INTERNAL_H */ 438 439