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 54 /* threshold for decompression synchronously */ 55 unsigned int max_sync_decompress_pages; 56 #endif 57 unsigned int mount_opt; 58 }; 59 60 struct 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) 109 110 enum { 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 */ 120 struct 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) 129 static 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 } 139 140 static 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 } 151 152 static 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 158 static 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 } 169 170 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp, 171 int orig_val) 172 { 173 preempt_enable(); 174 } 175 176 static 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) 213 214 static 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) 226 227 struct 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 short 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) 257 258 static 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 } 263 264 static 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 } 270 271 272 static 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 } 277 278 static 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 } 283 284 extern const struct super_operations erofs_sops; 285 286 extern const struct address_space_operations erofs_raw_access_aops; 287 extern 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 */ 314 enum { 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) 327 328 struct 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 342 int z_erofs_fill_inode(struct inode *inode); 343 int z_erofs_map_blocks_iter(struct inode *inode, 344 struct erofs_map_blocks *map, 345 int flags); 346 #else 347 static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; } 348 static 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 */ 357 struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr); 358 359 int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int); 360 361 /* inode.c */ 362 static 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 } 370 371 extern const struct inode_operations erofs_generic_iops; 372 extern const struct inode_operations erofs_symlink_iops; 373 extern const struct inode_operations erofs_fast_symlink_iops; 374 375 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir); 376 int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path, 377 struct kstat *stat, u32 request_mask, 378 unsigned int query_flags); 379 380 /* namei.c */ 381 extern const struct inode_operations erofs_dir_iops; 382 383 int erofs_namei(struct inode *dir, struct qstr *name, 384 erofs_nid_t *nid, unsigned int *d_type); 385 386 /* dir.c */ 387 extern const struct file_operations erofs_dir_fops; 388 389 /* utils.c / zdata.c */ 390 struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp); 391 392 #if (EROFS_PCPUBUF_NR_PAGES > 0) 393 void *erofs_get_pcpubuf(unsigned int pagenr); 394 #define erofs_put_pcpubuf(buf) do { \ 395 (void)&(buf); \ 396 preempt_enable(); \ 397 } while (0) 398 #else 399 static inline void *erofs_get_pcpubuf(unsigned int pagenr) 400 { 401 return ERR_PTR(-EOPNOTSUPP); 402 } 403 404 #define erofs_put_pcpubuf(buf) do {} while (0) 405 #endif 406 407 #ifdef CONFIG_EROFS_FS_ZIP 408 int erofs_workgroup_put(struct erofs_workgroup *grp); 409 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb, 410 pgoff_t index); 411 struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb, 412 struct erofs_workgroup *grp); 413 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp); 414 void erofs_shrinker_register(struct super_block *sb); 415 void erofs_shrinker_unregister(struct super_block *sb); 416 int __init erofs_init_shrinker(void); 417 void erofs_exit_shrinker(void); 418 int __init z_erofs_init_zip_subsystem(void); 419 void z_erofs_exit_zip_subsystem(void); 420 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi, 421 struct erofs_workgroup *egrp); 422 int erofs_try_to_free_cached_page(struct address_space *mapping, 423 struct page *page); 424 #else 425 static inline void erofs_shrinker_register(struct super_block *sb) {} 426 static inline void erofs_shrinker_unregister(struct super_block *sb) {} 427 static inline int erofs_init_shrinker(void) { return 0; } 428 static inline void erofs_exit_shrinker(void) {} 429 static inline int z_erofs_init_zip_subsystem(void) { return 0; } 430 static inline void z_erofs_exit_zip_subsystem(void) {} 431 #endif /* !CONFIG_EROFS_FS_ZIP */ 432 433 #define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */ 434 435 #endif /* __EROFS_INTERNAL_H */ 436 437