fs/erofs/internal.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2017-2018 HUAWEI, Inc.
   4  *             http://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_sb_info {
  50 #ifdef CONFIG_EROFS_FS_ZIP
  51         /* list for all registered superblocks, mainly for shrinker */
  52         struct list_head list;
  53         struct mutex umount_mutex;
  54
  55         /* managed XArray arranged in physical block number */
  56         struct xarray managed_pslots;
  57
  58         /* threshold for decompression synchronously */
  59         unsigned int max_sync_decompress_pages;
  60
  61         unsigned int shrinker_run_no;
  62
  63         /* current strategy of how to use managed cache */
  64         unsigned char cache_strategy;
  65
  66         /* pseudo inode to manage cached pages */
  67         struct inode *managed_cache;
  68 #endif  /* CONFIG_EROFS_FS_ZIP */
  69         u32 blocks;
  70         u32 meta_blkaddr;
  71 #ifdef CONFIG_EROFS_FS_XATTR
  72         u32 xattr_blkaddr;
  73 #endif
  74
  75         /* inode slot unit size in bit shift */
  76         unsigned char islotbits;
  77
  78         u32 build_time_nsec;
  79         u64 build_time;
  80
  81         /* what we really care is nid, rather than ino.. */
  82         erofs_nid_t root_nid;
  83         /* used for statfs, f_files - f_favail */
  84         u64 inos;
  85
  86         u8 uuid[16];                    /* 128-bit uuid for volume */
  87         u8 volume_name[16];             /* volume name */
  88         u32 feature_compat;
  89         u32 feature_incompat;
  90
  91         unsigned int mount_opt;
  92 };
  93
  94 #define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
  95 #define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
  96
  97 /* Mount flags set via mount options or defaults */
  98 #define EROFS_MOUNT_XATTR_USER          0x00000010
  99 #define EROFS_MOUNT_POSIX_ACL           0x00000020
 100
 101 #define clear_opt(sbi, option)  ((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
 102 #define set_opt(sbi, option)    ((sbi)->mount_opt |= EROFS_MOUNT_##option)
 103 #define test_opt(sbi, option)   ((sbi)->mount_opt & EROFS_MOUNT_##option)
 104
 105 #ifdef CONFIG_EROFS_FS_ZIP
 106 enum {
 107         EROFS_ZIP_CACHE_DISABLED,
 108         EROFS_ZIP_CACHE_READAHEAD,
 109         EROFS_ZIP_CACHE_READAROUND
 110 };
 111
 112 #define EROFS_LOCKED_MAGIC     (INT_MIN | 0xE0F510CCL)
 113
 114 /* basic unit of the workstation of a super_block */
 115 struct erofs_workgroup {
 116         /* the workgroup index in the workstation */
 117         pgoff_t index;
 118
 119         /* overall workgroup reference count */
 120         atomic_t refcount;
 121 };
 122
 123 #if defined(CONFIG_SMP)
 124 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
 125                                                  int val)
 126 {
 127         preempt_disable();
 128         if (val != atomic_cmpxchg(&grp->refcount, val, EROFS_LOCKED_MAGIC)) {
 129                 preempt_enable();
 130                 return false;
 131         }
 132         return true;
 133 }
 134
 135 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
 136                                             int orig_val)
 137 {
 138         /*
 139          * other observers should notice all modifications
 140          * in the freezing period.
 141          */
 142         smp_mb();
 143         atomic_set(&grp->refcount, orig_val);
 144         preempt_enable();
 145 }
 146
 147 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
 148 {
 149         return atomic_cond_read_relaxed(&grp->refcount,
 150                                         VAL != EROFS_LOCKED_MAGIC);
 151 }
 152 #else
 153 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
 154                                                  int val)
 155 {
 156         preempt_disable();
 157         /* no need to spin on UP platforms, let's just disable preemption. */
 158         if (val != atomic_read(&grp->refcount)) {
 159                 preempt_enable();
 160                 return false;
 161         }
 162         return true;
 163 }
 164
 165 static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
 166                                             int orig_val)
 167 {
 168         preempt_enable();
 169 }
 170
 171 static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
 172 {
 173         int v = atomic_read(&grp->refcount);
 174
 175         /* workgroup is never freezed on uniprocessor systems */
 176         DBG_BUGON(v == EROFS_LOCKED_MAGIC);
 177         return v;
 178 }
 179 #endif  /* !CONFIG_SMP */
 180
 181 /* hard limit of pages per compressed cluster */
 182 #define Z_EROFS_CLUSTER_MAX_PAGES       (CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT)
 183 #define EROFS_PCPUBUF_NR_PAGES          Z_EROFS_CLUSTER_MAX_PAGES
 184 #else
 185 #define EROFS_PCPUBUF_NR_PAGES          0
 186 #endif  /* !CONFIG_EROFS_FS_ZIP */
 187
 188 /* we strictly follow PAGE_SIZE and no buffer head yet */
 189 #define LOG_BLOCK_SIZE          PAGE_SHIFT
 190
 191 #undef LOG_SECTORS_PER_BLOCK
 192 #define LOG_SECTORS_PER_BLOCK   (PAGE_SHIFT - 9)
 193
 194 #undef SECTORS_PER_BLOCK
 195 #define SECTORS_PER_BLOCK       (1 << SECTORS_PER_BLOCK)
 196
 197 #define EROFS_BLKSIZ            (1 << LOG_BLOCK_SIZE)
 198
 199 #if (EROFS_BLKSIZ % 4096 || !EROFS_BLKSIZ)
 200 #error erofs cannot be used in this platform
 201 #endif
 202
 203 #define ROOT_NID(sb)            ((sb)->root_nid)
 204
 205 #define erofs_blknr(addr)       ((addr) / EROFS_BLKSIZ)
 206 #define erofs_blkoff(addr)      ((addr) % EROFS_BLKSIZ)
 207 #define blknr_to_addr(nr)       ((erofs_off_t)(nr) * EROFS_BLKSIZ)
 208
 209 static inline erofs_off_t iloc(struct erofs_sb_info *sbi, erofs_nid_t nid)
 210 {
 211         return blknr_to_addr(sbi->meta_blkaddr) + (nid << sbi->islotbits);
 212 }
 213
 214 /* atomic flag definitions */
 215 #define EROFS_I_EA_INITED_BIT   0
 216 #define EROFS_I_Z_INITED_BIT    1
 217
 218 /* bitlock definitions (arranged in reverse order) */
 219 #define EROFS_I_BL_XATTR_BIT    (BITS_PER_LONG - 1)
 220 #define EROFS_I_BL_Z_BIT        (BITS_PER_LONG - 2)
 221
 222 struct erofs_inode {
 223         erofs_nid_t nid;
 224
 225         /* atomic flags (including bitlocks) */
 226         unsigned long flags;
 227
 228         unsigned char datalayout;
 229         unsigned char inode_isize;
 230         unsigned short xattr_isize;
 231
 232         unsigned int xattr_shared_count;
 233         unsigned int *xattr_shared_xattrs;
 234
 235         union {
 236                 erofs_blk_t raw_blkaddr;
 237 #ifdef CONFIG_EROFS_FS_ZIP
 238                 struct {
 239                         unsigned short z_advise;
 240                         unsigned char  z_algorithmtype[2];
 241                         unsigned char  z_logical_clusterbits;
 242                         unsigned char  z_physical_clusterbits[2];
 243                 };
 244 #endif  /* CONFIG_EROFS_FS_ZIP */
 245         };
 246         /* the corresponding vfs inode */
 247         struct inode vfs_inode;
 248 };
 249
 250 #define EROFS_I(ptr)    \
 251         container_of(ptr, struct erofs_inode, vfs_inode)
 252
 253 static inline unsigned long erofs_inode_datablocks(struct inode *inode)
 254 {
 255         /* since i_size cannot be changed */
 256         return DIV_ROUND_UP(inode->i_size, EROFS_BLKSIZ);
 257 }
 258
 259 static inline unsigned int erofs_bitrange(unsigned int value, unsigned int bit,
 260                                           unsigned int bits)
 261 {
 262
 263         return (value >> bit) & ((1 << bits) - 1);
 264 }
 265
 266
 267 static inline unsigned int erofs_inode_version(unsigned int value)
 268 {
 269         return erofs_bitrange(value, EROFS_I_VERSION_BIT,
 270                               EROFS_I_VERSION_BITS);
 271 }
 272
 273 static inline unsigned int erofs_inode_datalayout(unsigned int value)
 274 {
 275         return erofs_bitrange(value, EROFS_I_DATALAYOUT_BIT,
 276                               EROFS_I_DATALAYOUT_BITS);
 277 }
 278
 279 extern const struct super_operations erofs_sops;
 280
 281 extern const struct address_space_operations erofs_raw_access_aops;
 282 extern const struct address_space_operations z_erofs_aops;
 283
 284 /*
 285  * Logical to physical block mapping, used by erofs_map_blocks()
 286  *
 287  * Different with other file systems, it is used for 2 access modes:
 288  *
 289  * 1) RAW access mode:
 290  *
 291  * Users pass a valid (m_lblk, m_lofs -- usually 0) pair,
 292  * and get the valid m_pblk, m_pofs and the longest m_len(in bytes).
 293  *
 294  * Note that m_lblk in the RAW access mode refers to the number of
 295  * the compressed ondisk block rather than the uncompressed
 296  * in-memory block for the compressed file.
 297  *
 298  * m_pofs equals to m_lofs except for the inline data page.
 299  *
 300  * 2) Normal access mode:
 301  *
 302  * If the inode is not compressed, it has no difference with
 303  * the RAW access mode. However, if the inode is compressed,
 304  * users should pass a valid (m_lblk, m_lofs) pair, and get
 305  * the needed m_pblk, m_pofs, m_len to get the compressed data
 306  * and the updated m_lblk, m_lofs which indicates the start
 307  * of the corresponding uncompressed data in the file.
 308  */
 309 enum {
 310         BH_Zipped = BH_PrivateStart,
 311         BH_FullMapped,
 312 };
 313
 314 /* Has a disk mapping */
 315 #define EROFS_MAP_MAPPED        (1 << BH_Mapped)
 316 /* Located in metadata (could be copied from bd_inode) */
 317 #define EROFS_MAP_META          (1 << BH_Meta)
 318 /* The extent has been compressed */
 319 #define EROFS_MAP_ZIPPED        (1 << BH_Zipped)
 320 /* The length of extent is full */
 321 #define EROFS_MAP_FULL_MAPPED   (1 << BH_FullMapped)
 322
 323 struct erofs_map_blocks {
 324         erofs_off_t m_pa, m_la;
 325         u64 m_plen, m_llen;
 326
 327         unsigned int m_flags;
 328
 329         struct page *mpage;
 330 };
 331
 332 /* Flags used by erofs_map_blocks() */
 333 #define EROFS_GET_BLOCKS_RAW    0x0001
 334
 335 /* zmap.c */
 336 #ifdef CONFIG_EROFS_FS_ZIP
 337 int z_erofs_fill_inode(struct inode *inode);
 338 int z_erofs_map_blocks_iter(struct inode *inode,
 339                             struct erofs_map_blocks *map,
 340                             int flags);
 341 #else
 342 static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
 343 static inline int z_erofs_map_blocks_iter(struct inode *inode,
 344                                           struct erofs_map_blocks *map,
 345                                           int flags)
 346 {
 347         return -EOPNOTSUPP;
 348 }
 349 #endif  /* !CONFIG_EROFS_FS_ZIP */
 350
 351 /* data.c */
 352 struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr);
 353
 354 int erofs_map_blocks(struct inode *, struct erofs_map_blocks *, int);
 355
 356 /* inode.c */
 357 static inline unsigned long erofs_inode_hash(erofs_nid_t nid)
 358 {
 359 #if BITS_PER_LONG == 32
 360         return (nid >> 32) ^ (nid & 0xffffffff);
 361 #else
 362         return nid;
 363 #endif
 364 }
 365
 366 extern const struct inode_operations erofs_generic_iops;
 367 extern const struct inode_operations erofs_symlink_iops;
 368 extern const struct inode_operations erofs_fast_symlink_iops;
 369
 370 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid, bool dir);
 371 int erofs_getattr(const struct path *path, struct kstat *stat,
 372                   u32 request_mask, unsigned int query_flags);
 373
 374 /* namei.c */
 375 extern const struct inode_operations erofs_dir_iops;
 376
 377 int erofs_namei(struct inode *dir, struct qstr *name,
 378                 erofs_nid_t *nid, unsigned int *d_type);
 379
 380 /* dir.c */
 381 extern const struct file_operations erofs_dir_fops;
 382
 383 /* utils.c / zdata.c */
 384 struct page *erofs_allocpage(struct list_head *pool, gfp_t gfp);
 385
 386 #if (EROFS_PCPUBUF_NR_PAGES > 0)
 387 void *erofs_get_pcpubuf(unsigned int pagenr);
 388 #define erofs_put_pcpubuf(buf) do { \
 389         (void)&(buf);   \
 390         preempt_enable();       \
 391 } while (0)
 392 #else
 393 static inline void *erofs_get_pcpubuf(unsigned int pagenr)
 394 {
 395         return ERR_PTR(-EOPNOTSUPP);
 396 }
 397
 398 #define erofs_put_pcpubuf(buf) do {} while (0)
 399 #endif
 400
 401 #ifdef CONFIG_EROFS_FS_ZIP
 402 int erofs_workgroup_put(struct erofs_workgroup *grp);
 403 struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
 404                                              pgoff_t index);
 405 struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
 406                                                struct erofs_workgroup *grp);
 407 void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
 408 void erofs_shrinker_register(struct super_block *sb);
 409 void erofs_shrinker_unregister(struct super_block *sb);
 410 int __init erofs_init_shrinker(void);
 411 void erofs_exit_shrinker(void);
 412 int __init z_erofs_init_zip_subsystem(void);
 413 void z_erofs_exit_zip_subsystem(void);
 414 int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
 415                                        struct erofs_workgroup *egrp);
 416 int erofs_try_to_free_cached_page(struct address_space *mapping,
 417                                   struct page *page);
 418 #else
 419 static inline void erofs_shrinker_register(struct super_block *sb) {}
 420 static inline void erofs_shrinker_unregister(struct super_block *sb) {}
 421 static inline int erofs_init_shrinker(void) { return 0; }
 422 static inline void erofs_exit_shrinker(void) {}
 423 static inline int z_erofs_init_zip_subsystem(void) { return 0; }
 424 static inline void z_erofs_exit_zip_subsystem(void) {}
 425 #endif  /* !CONFIG_EROFS_FS_ZIP */
 426
 427 #define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
 428
 429 #endif  /* __EROFS_INTERNAL_H */
 430