fs/erofs/internal.h

   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(const struct path *path, struct kstat *stat,
 377                   u32 request_mask, unsigned int query_flags);
 378
 379 /* namei.c */
 380 extern const struct inode_operations erofs_dir_iops;
 381
 382 int erofs_namei(struct inode *dir, struct qstr *name,
 383                 erofs_nid_t *nid, unsigned int *d_type);
 384
 385 /* dir.c */
 386 extern const struct file_operations erofs_dir_fops;
 387
 388 /* utils.c / zdata.c */
 389 struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
 390
 391 #if (EROFS_PCPUBUF_NR_PAGES > 0)
 392 void *erofs_get_pcpubuf(unsigned int pagenr);
 393 #define erofs_put_pcpubuf(buf) do { \
 394         (void)&(buf);   \
 395         preempt_enable();       \
 396 } while (0)
 397 #else
 398 static 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
 407 int erofs_workgroup_put(struct erofs_workgroup *grp);
 408 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
 409                                              pgoff_t index);
 410 struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
 411                                                struct erofs_workgroup *grp);
 412 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
 413 void erofs_shrinker_register(struct super_block *sb);
 414 void erofs_shrinker_unregister(struct super_block *sb);
 415 int __init erofs_init_shrinker(void);
 416 void erofs_exit_shrinker(void);
 417 int __init z_erofs_init_zip_subsystem(void);
 418 void z_erofs_exit_zip_subsystem(void);
 419 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
 420                                        struct erofs_workgroup *egrp);
 421 int erofs_try_to_free_cached_page(struct address_space *mapping,
 422                                   struct page *page);
 423 #else
 424 static inline void erofs_shrinker_register(struct super_block *sb) {}
 425 static inline void erofs_shrinker_unregister(struct super_block *sb) {}
 426 static inline int erofs_init_shrinker(void) { return 0; }
 427 static inline void erofs_exit_shrinker(void) {}
 428 static inline int z_erofs_init_zip_subsystem(void) { return 0; }
 429 static 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