LXR linux/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 * 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
  45typedef u64 erofs_nid_t;
  46typedef u64 erofs_off_t;
  47/* data type for filesystem-wide blocks number */
  48typedef u32 erofs_blk_t;
  49
  50struct 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 */
  64struct 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
  71struct 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
 128enum {
 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 */
 138struct 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)
 147static 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
 158static 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
 170static 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
 176static 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
 188static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
 189                                            int orig_val)
 190{
 191        preempt_enable();
 192}
 193
 194static 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
 226static 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) \
 232static inline bool erofs_sb_has_##name(struct erofs_sb_info *sbi) \
 233{ \
 234        return sbi->feature_##compat & EROFS_FEATURE_##feature; \
 235}
 236
 237EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
 238EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
 239EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
 240EROFS_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
 250struct 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
 284static 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
 290static 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
 298static 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
 304static 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
 310extern const struct super_operations erofs_sops;
 311
 312extern const struct address_space_operations erofs_raw_access_aops;
 313extern 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 */
 340enum {
 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
 354struct 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 */
 372extern const struct iomap_ops z_erofs_iomap_report_ops;
 373
 374#ifdef CONFIG_EROFS_FS_ZIP
 375int z_erofs_fill_inode(struct inode *inode);
 376int z_erofs_map_blocks_iter(struct inode *inode,
 377                            struct erofs_map_blocks *map,
 378                            int flags);
 379#else
 380static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
 381static 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 */
 390extern const struct file_operations erofs_file_fops;
 391struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
 392int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 393                 u64 start, u64 len);
 394
 395/* inode.c */
 396static 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
 405extern const struct inode_operations erofs_generic_iops;
 406extern const struct inode_operations erofs_symlink_iops;
 407extern const struct inode_operations erofs_fast_symlink_iops;
 408
 409struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
 410int 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 */
 415extern const struct inode_operations erofs_dir_iops;
 416
 417int erofs_namei(struct inode *dir, struct qstr *name,
 418                erofs_nid_t *nid, unsigned int *d_type);
 419
 420/* dir.c */
 421extern const struct file_operations erofs_dir_fops;
 422
 423static 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 */
 439void *erofs_get_pcpubuf(unsigned int requiredpages);
 440void erofs_put_pcpubuf(void *ptr);
 441int erofs_pcpubuf_growsize(unsigned int nrpages);
 442void erofs_pcpubuf_init(void);
 443void erofs_pcpubuf_exit(void);
 444
 445/* utils.c / zdata.c */
 446struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
 447
 448#ifdef CONFIG_EROFS_FS_ZIP
 449int erofs_workgroup_put(struct erofs_workgroup *grp);
 450struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
 451                                             pgoff_t index);
 452struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
 453                                               struct erofs_workgroup *grp);
 454void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
 455void erofs_shrinker_register(struct super_block *sb);
 456void erofs_shrinker_unregister(struct super_block *sb);
 457int __init erofs_init_shrinker(void);
 458void erofs_exit_shrinker(void);
 459int __init z_erofs_init_zip_subsystem(void);
 460void z_erofs_exit_zip_subsystem(void);
 461int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
 462                                       struct erofs_workgroup *egrp);
 463int erofs_try_to_free_cached_page(struct page *page);
 464int 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
 468static inline void erofs_shrinker_register(struct super_block *sb) {}
 469static inline void erofs_shrinker_unregister(struct super_block *sb) {}
 470static inline int erofs_init_shrinker(void) { return 0; }
 471static inline void erofs_exit_shrinker(void) {}
 472static inline int z_erofs_init_zip_subsystem(void) { return 0; }
 473static inline void z_erofs_exit_zip_subsystem(void) {}
 474static 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