fs/logfs/logfs.h

   1 /*
   2  * fs/logfs/logfs.h
   3  *
   4  * As should be obvious for Linux kernel code, license is GPLv2
   5  *
   6  * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
   7  *
   8  * Private header for logfs.
   9  */
  10 #ifndef FS_LOGFS_LOGFS_H
  11 #define FS_LOGFS_LOGFS_H
  12
  13 #undef __CHECK_ENDIAN__
  14 #define __CHECK_ENDIAN__
  15
  16 #include <linux/btree.h>
  17 #include <linux/crc32.h>
  18 #include <linux/fs.h>
  19 #include <linux/kernel.h>
  20 #include <linux/mempool.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/mtd/mtd.h>
  23 #include "logfs_abi.h"
  24
  25 #define LOGFS_DEBUG_SUPER       (0x0001)
  26 #define LOGFS_DEBUG_SEGMENT     (0x0002)
  27 #define LOGFS_DEBUG_JOURNAL     (0x0004)
  28 #define LOGFS_DEBUG_DIR         (0x0008)
  29 #define LOGFS_DEBUG_FILE        (0x0010)
  30 #define LOGFS_DEBUG_INODE       (0x0020)
  31 #define LOGFS_DEBUG_READWRITE   (0x0040)
  32 #define LOGFS_DEBUG_GC          (0x0080)
  33 #define LOGFS_DEBUG_GC_NOISY    (0x0100)
  34 #define LOGFS_DEBUG_ALIASES     (0x0200)
  35 #define LOGFS_DEBUG_BLOCKMOVE   (0x0400)
  36 #define LOGFS_DEBUG_ALL         (0xffffffff)
  37
  38 #define LOGFS_DEBUG             (0x01)
  39 /*
  40  * To enable specific log messages, simply define LOGFS_DEBUG to match any
  41  * or all of the above.
  42  */
  43 #ifndef LOGFS_DEBUG
  44 #define LOGFS_DEBUG             (0)
  45 #endif
  46
  47 #define log_cond(cond, fmt, arg...) do {        \
  48         if (cond)                               \
  49                 printk(KERN_DEBUG fmt, ##arg);  \
  50 } while (0)
  51
  52 #define log_super(fmt, arg...) \
  53         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_SUPER, fmt, ##arg)
  54 #define log_segment(fmt, arg...) \
  55         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_SEGMENT, fmt, ##arg)
  56 #define log_journal(fmt, arg...) \
  57         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_JOURNAL, fmt, ##arg)
  58 #define log_dir(fmt, arg...) \
  59         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_DIR, fmt, ##arg)
  60 #define log_file(fmt, arg...) \
  61         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_FILE, fmt, ##arg)
  62 #define log_inode(fmt, arg...) \
  63         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_INODE, fmt, ##arg)
  64 #define log_readwrite(fmt, arg...) \
  65         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_READWRITE, fmt, ##arg)
  66 #define log_gc(fmt, arg...) \
  67         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_GC, fmt, ##arg)
  68 #define log_gc_noisy(fmt, arg...) \
  69         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_GC_NOISY, fmt, ##arg)
  70 #define log_aliases(fmt, arg...) \
  71         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_ALIASES, fmt, ##arg)
  72 #define log_blockmove(fmt, arg...) \
  73         log_cond(LOGFS_DEBUG & LOGFS_DEBUG_BLOCKMOVE, fmt, ##arg)
  74
  75 #define PG_pre_locked           PG_owner_priv_1
  76 #define PagePreLocked(page)     test_bit(PG_pre_locked, &(page)->flags)
  77 #define SetPagePreLocked(page)  set_bit(PG_pre_locked, &(page)->flags)
  78 #define ClearPagePreLocked(page) clear_bit(PG_pre_locked, &(page)->flags)
  79
  80 /* FIXME: This should really be somewhere in the 64bit area. */
  81 #define LOGFS_LINK_MAX          (1<<30)
  82
  83 /* Read-only filesystem */
  84 #define LOGFS_SB_FLAG_RO        0x0001
  85 #define LOGFS_SB_FLAG_DIRTY     0x0002
  86 #define LOGFS_SB_FLAG_OBJ_ALIAS 0x0004
  87 #define LOGFS_SB_FLAG_SHUTDOWN  0x0008
  88
  89 /* Write Control Flags */
  90 #define WF_LOCK                 0x01 /* take write lock */
  91 #define WF_WRITE                0x02 /* write block */
  92 #define WF_DELETE               0x04 /* delete old block */
  93
  94 typedef u8 __bitwise level_t;
  95 typedef u8 __bitwise gc_level_t;
  96
  97 #define LEVEL(level) ((__force level_t)(level))
  98 #define GC_LEVEL(gc_level) ((__force gc_level_t)(gc_level))
  99
 100 #define SUBLEVEL(level) ( (void)((level) == LEVEL(1)),  \
 101                 (__force level_t)((__force u8)(level) - 1) )
 102
 103 /**
 104  * struct logfs_area - area management information
 105  *
 106  * @a_sb:                       the superblock this area belongs to
 107  * @a_is_open:                  1 if the area is currently open, else 0
 108  * @a_segno:                    segment number of area
 109  * @a_written_bytes:            number of bytes already written back
 110  * @a_used_bytes:               number of used bytes
 111  * @a_ops:                      area operations (either journal or ostore)
 112  * @a_erase_count:              erase count
 113  * @a_level:                    GC level
 114  */
 115 struct logfs_area { /* a segment open for writing */
 116         struct super_block *a_sb;
 117         int     a_is_open;
 118         u32     a_segno;
 119         u32     a_written_bytes;
 120         u32     a_used_bytes;
 121         const struct logfs_area_ops *a_ops;
 122         u32     a_erase_count;
 123         gc_level_t a_level;
 124 };
 125
 126 /**
 127  * struct logfs_area_ops - area operations
 128  *
 129  * @get_free_segment:           fill area->ofs with the offset of a free segment
 130  * @get_erase_count:            fill area->erase_count (needs area->ofs)
 131  * @erase_segment:              erase and setup segment
 132  */
 133 struct logfs_area_ops {
 134         void    (*get_free_segment)(struct logfs_area *area);
 135         void    (*get_erase_count)(struct logfs_area *area);
 136         int     (*erase_segment)(struct logfs_area *area);
 137 };
 138
 139 /**
 140  * struct logfs_device_ops - device access operations
 141  *
 142  * @readpage:                   read one page (mm page)
 143  * @writeseg:                   write one segment.  may be a partial segment
 144  * @erase:                      erase one segment
 145  * @read:                       read from the device
 146  * @erase:                      erase part of the device
 147  */
 148 struct logfs_device_ops {
 149         struct page *(*find_first_sb)(struct super_block *sb, u64 *ofs);
 150         struct page *(*find_last_sb)(struct super_block *sb, u64 *ofs);
 151         int (*write_sb)(struct super_block *sb, struct page *page);
 152         int (*readpage)(void *_sb, struct page *page);
 153         void (*writeseg)(struct super_block *sb, u64 ofs, size_t len);
 154         int (*erase)(struct super_block *sb, loff_t ofs, size_t len,
 155                         int ensure_write);
 156         void (*sync)(struct super_block *sb);
 157         void (*put_device)(struct super_block *sb);
 158 };
 159
 160 /**
 161  * struct candidate_list - list of similar candidates
 162  */
 163 struct candidate_list {
 164         struct rb_root rb_tree;
 165         int count;
 166         int maxcount;
 167         int sort_by_ec;
 168 };
 169
 170 /**
 171  * struct gc_candidate - "candidate" segment to be garbage collected next
 172  *
 173  * @list:                       list (either free of low)
 174  * @segno:                      segment number
 175  * @valid:                      number of valid bytes
 176  * @erase_count:                erase count of segment
 177  * @dist:                       distance from tree root
 178  *
 179  * Candidates can be on two lists.  The free list contains electees rather
 180  * than candidates - segments that no longer contain any valid data.  The
 181  * low list contains candidates to be picked for GC.  It should be kept
 182  * short.  It is not required to always pick a perfect candidate.  In the
 183  * worst case GC will have to move more data than absolutely necessary.
 184  */
 185 struct gc_candidate {
 186         struct rb_node rb_node;
 187         struct candidate_list *list;
 188         u32     segno;
 189         u32     valid;
 190         u32     erase_count;
 191         u8      dist;
 192 };
 193
 194 /**
 195  * struct logfs_journal_entry - temporary structure used during journal scan
 196  *
 197  * @used:
 198  * @version:                    normalized version
 199  * @len:                        length
 200  * @offset:                     offset
 201  */
 202 struct logfs_journal_entry {
 203         int used;
 204         s16 version;
 205         u16 len;
 206         u16 datalen;
 207         u64 offset;
 208 };
 209
 210 enum transaction_state {
 211         CREATE_1 = 1,
 212         CREATE_2,
 213         UNLINK_1,
 214         UNLINK_2,
 215         CROSS_RENAME_1,
 216         CROSS_RENAME_2,
 217         TARGET_RENAME_1,
 218         TARGET_RENAME_2,
 219         TARGET_RENAME_3
 220 };
 221
 222 /**
 223  * struct logfs_transaction - essential fields to support atomic dirops
 224  *
 225  * @ino:                        target inode
 226  * @dir:                        inode of directory containing dentry
 227  * @pos:                        pos of dentry in directory
 228  */
 229 struct logfs_transaction {
 230         enum transaction_state state;
 231         u64      ino;
 232         u64      dir;
 233         u64      pos;
 234 };
 235
 236 /**
 237  * struct logfs_shadow - old block in the shadow of a not-yet-committed new one
 238  * @old_ofs:                    offset of old block on medium
 239  * @new_ofs:                    offset of new block on medium
 240  * @ino:                        inode number
 241  * @bix:                        block index
 242  * @old_len:                    size of old block, including header
 243  * @new_len:                    size of new block, including header
 244  * @level:                      block level
 245  */
 246 struct logfs_shadow {
 247         u64 old_ofs;
 248         u64 new_ofs;
 249         u64 ino;
 250         u64 bix;
 251         int old_len;
 252         int new_len;
 253         gc_level_t gc_level;
 254 };
 255
 256 /**
 257  * struct shadow_tree
 258  * @new:                        shadows where old_ofs==0, indexed by new_ofs
 259  * @old:                        shadows where old_ofs!=0, indexed by old_ofs
 260  */
 261 struct shadow_tree {
 262         struct btree_head64 new;
 263         struct btree_head64 old;
 264 };
 265
 266 struct object_alias_item {
 267         struct list_head list;
 268         __be64 val;
 269         int child_no;
 270 };
 271
 272 /**
 273  * struct logfs_block - contains any block state
 274  * @type:                       indirect block or inode
 275  * @full:                       number of fully populated children
 276  * @partial:                    number of partially populated children
 277  *
 278  * Most blocks are directly represented by page cache pages.  But when a block
 279  * becomes dirty, is part of a transaction, contains aliases or is otherwise
 280  * special, a struct logfs_block is allocated to track the additional state.
 281  * Inodes are very similar to indirect blocks, so they can also get one of
 282  * these structures added when appropriate.
 283  */
 284 #define BLOCK_INDIRECT  1       /* Indirect block */
 285 #define BLOCK_INODE     2       /* Inode */
 286 struct logfs_block_ops;
 287 struct logfs_block {
 288         struct list_head alias_list;
 289         struct list_head item_list;
 290         struct super_block *sb;
 291         u64 ino;
 292         u64 bix;
 293         level_t level;
 294         struct page *page;
 295         struct inode *inode;
 296         struct logfs_transaction *ta;
 297         unsigned long alias_map[LOGFS_BLOCK_FACTOR / BITS_PER_LONG];
 298         struct logfs_block_ops *ops;
 299         int full;
 300         int partial;
 301         int reserved_bytes;
 302 };
 303
 304 typedef int write_alias_t(struct super_block *sb, u64 ino, u64 bix,
 305                 level_t level, int child_no, __be64 val);
 306 struct logfs_block_ops {
 307         void    (*write_block)(struct logfs_block *block);
 308         gc_level_t      (*block_level)(struct logfs_block *block);
 309         void    (*free_block)(struct super_block *sb, struct logfs_block*block);
 310         int     (*write_alias)(struct super_block *sb,
 311                         struct logfs_block *block,
 312                         write_alias_t *write_one_alias);
 313 };
 314
 315 struct logfs_super {
 316         struct mtd_info *s_mtd;                 /* underlying device */
 317         struct block_device *s_bdev;            /* underlying device */
 318         const struct logfs_device_ops *s_devops;/* device access */
 319         struct inode    *s_master_inode;        /* inode file */
 320         struct inode    *s_segfile_inode;       /* segment file */
 321         struct inode *s_mapping_inode;          /* device mapping */
 322         atomic_t s_pending_writes;              /* outstanting bios */
 323         long     s_flags;
 324         mempool_t *s_btree_pool;                /* for btree nodes */
 325         mempool_t *s_alias_pool;                /* aliases in segment.c */
 326         u64      s_feature_incompat;
 327         u64      s_feature_ro_compat;
 328         u64      s_feature_compat;
 329         u64      s_feature_flags;
 330         u64      s_sb_ofs[2];
 331         struct page *s_erase_page;              /* for dev_bdev.c */
 332         /* alias.c fields */
 333         struct btree_head32 s_segment_alias;    /* remapped segments */
 334         int      s_no_object_aliases;
 335         struct list_head s_object_alias;        /* remapped objects */
 336         struct btree_head128 s_object_alias_tree; /* remapped objects */
 337         struct mutex s_object_alias_mutex;
 338         /* dir.c fields */
 339         struct mutex s_dirop_mutex;             /* for creat/unlink/rename */
 340         u64      s_victim_ino;                  /* used for atomic dir-ops */
 341         u64      s_rename_dir;                  /* source directory ino */
 342         u64      s_rename_pos;                  /* position of source dd */
 343         /* gc.c fields */
 344         long     s_segsize;                     /* size of a segment */
 345         int      s_segshift;                    /* log2 of segment size */
 346         long     s_segmask;                     /* 1 << s_segshift - 1 */
 347         long     s_no_segs;                     /* segments on device */
 348         long     s_no_journal_segs;             /* segments used for journal */
 349         long     s_no_blocks;                   /* blocks per segment */
 350         long     s_writesize;                   /* minimum write size */
 351         int      s_writeshift;                  /* log2 of write size */
 352         u64      s_size;                        /* filesystem size */
 353         struct logfs_area *s_area[LOGFS_NO_AREAS];      /* open segment array */
 354         u64      s_gec;                         /* global erase count */
 355         u64      s_wl_gec_ostore;               /* time of last wl event */
 356         u64      s_wl_gec_journal;              /* time of last wl event */
 357         u64      s_sweeper;                     /* current sweeper pos */
 358         u8       s_ifile_levels;                /* max level of ifile */
 359         u8       s_iblock_levels;               /* max level of regular files */
 360         u8       s_data_levels;                 /* # of segments to leaf block*/
 361         u8       s_total_levels;                /* sum of above three */
 362         struct btree_head32 s_cand_tree;        /* all candidates */
 363         struct candidate_list s_free_list;      /* 100% free segments */
 364         struct candidate_list s_reserve_list;   /* Bad segment reserve */
 365         struct candidate_list s_low_list[LOGFS_NO_AREAS];/* good candidates */
 366         struct candidate_list s_ec_list;        /* wear level candidates */
 367         struct btree_head32 s_reserved_segments;/* sb, journal, bad, etc. */
 368         /* inode.c fields */
 369         u64      s_last_ino;                    /* highest ino used */
 370         long     s_inos_till_wrap;
 371         u32      s_generation;                  /* i_generation for new files */
 372         struct list_head s_freeing_list;        /* inodes being freed */
 373         /* journal.c fields */
 374         struct mutex s_journal_mutex;
 375         void    *s_je;                          /* journal entry to compress */
 376         void    *s_compressed_je;               /* block to write to journal */
 377         u32      s_journal_seg[LOGFS_JOURNAL_SEGS]; /* journal segments */
 378         u32      s_journal_ec[LOGFS_JOURNAL_SEGS]; /* journal erasecounts */
 379         u64      s_last_version;
 380         struct logfs_area *s_journal_area;      /* open journal segment */
 381         __be64  s_je_array[64];
 382         int     s_no_je;
 383
 384         int      s_sum_index;                   /* for the 12 summaries */
 385         struct shadow_tree s_shadow_tree;
 386         int      s_je_fill;                     /* index of current je */
 387         /* readwrite.c fields */
 388         struct mutex s_write_mutex;
 389         int      s_lock_count;
 390         mempool_t *s_block_pool;                /* struct logfs_block pool */
 391         mempool_t *s_shadow_pool;               /* struct logfs_shadow pool */
 392         /*
 393          * Space accounting:
 394          * - s_used_bytes specifies space used to store valid data objects.
 395          * - s_dirty_used_bytes is space used to store non-committed data
 396          *   objects.  Those objects have already been written themselves,
 397          *   but they don't become valid until all indirect blocks up to the
 398          *   journal have been written as well.
 399          * - s_dirty_free_bytes is space used to store the old copy of a
 400          *   replaced object, as long as the replacement is non-committed.
 401          *   In other words, it is the amount of space freed when all dirty
 402          *   blocks are written back.
 403          * - s_free_bytes is the amount of free space available for any
 404          *   purpose.
 405          * - s_root_reserve is the amount of free space available only to
 406          *   the root user.  Non-privileged users can no longer write once
 407          *   this watermark has been reached.
 408          * - s_speed_reserve is space which remains unused to speed up
 409          *   garbage collection performance.
 410          * - s_dirty_pages is the space reserved for currently dirty pages.
 411          *   It is a pessimistic estimate, so some/most will get freed on
 412          *   page writeback.
 413          *
 414          * s_used_bytes + s_free_bytes + s_speed_reserve = total usable size
 415          */
 416         u64      s_free_bytes;
 417         u64      s_used_bytes;
 418         u64      s_dirty_free_bytes;
 419         u64      s_dirty_used_bytes;
 420         u64      s_root_reserve;
 421         u64      s_speed_reserve;
 422         u64      s_dirty_pages;
 423         /* Bad block handling:
 424          * - s_bad_seg_reserve is a number of segments usually kept
 425          *   free.  When encountering bad blocks, the affected segment's data
 426          *   is _temporarily_ moved to a reserved segment.
 427          * - s_bad_segments is the number of known bad segments.
 428          */
 429         u32      s_bad_seg_reserve;
 430         u32      s_bad_segments;
 431 };
 432
 433 /**
 434  * struct logfs_inode - in-memory inode
 435  *
 436  * @vfs_inode:                  struct inode
 437  * @li_data:                    data pointers
 438  * @li_used_bytes:              number of used bytes
 439  * @li_freeing_list:            used to track inodes currently being freed
 440  * @li_flags:                   inode flags
 441  * @li_refcount:                number of internal (GC-induced) references
 442  */
 443 struct logfs_inode {
 444         struct inode vfs_inode;
 445         u64     li_data[LOGFS_EMBEDDED_FIELDS];
 446         u64     li_used_bytes;
 447         struct list_head li_freeing_list;
 448         struct logfs_block *li_block;
 449         u32     li_flags;
 450         u8      li_height;
 451         int     li_refcount;
 452 };
 453
 454 #define journal_for_each(__i) for (__i = 0; __i < LOGFS_JOURNAL_SEGS; __i++)
 455 #define for_each_area(__i) for (__i = 0; __i < LOGFS_NO_AREAS; __i++)
 456 #define for_each_area_down(__i) for (__i = LOGFS_NO_AREAS - 1; __i >= 0; __i--)
 457
 458 /* compr.c */
 459 int logfs_compress(void *in, void *out, size_t inlen, size_t outlen);
 460 int logfs_uncompress(void *in, void *out, size_t inlen, size_t outlen);
 461 int __init logfs_compr_init(void);
 462 void logfs_compr_exit(void);
 463
 464 /* dev_bdev.c */
 465 #ifdef CONFIG_BLOCK
 466 int logfs_get_sb_bdev(struct file_system_type *type, int flags,
 467                 const char *devname, struct vfsmount *mnt);
 468 #else
 469 static inline int logfs_get_sb_bdev(struct file_system_type *type, int flags,
 470                 const char *devname, struct vfsmount *mnt)
 471 {
 472         return -ENODEV;
 473 }
 474 #endif
 475
 476 /* dev_mtd.c */
 477 #ifdef CONFIG_MTD
 478 int logfs_get_sb_mtd(struct file_system_type *type, int flags,
 479                 int mtdnr, struct vfsmount *mnt);
 480 #else
 481 static inline int logfs_get_sb_mtd(struct file_system_type *type, int flags,
 482                 int mtdnr, struct vfsmount *mnt)
 483 {
 484         return -ENODEV;
 485 }
 486 #endif
 487
 488 /* dir.c */
 489 extern const struct inode_operations logfs_symlink_iops;
 490 extern const struct inode_operations logfs_dir_iops;
 491 extern const struct file_operations logfs_dir_fops;
 492 int logfs_replay_journal(struct super_block *sb);
 493
 494 /* file.c */
 495 extern const struct inode_operations logfs_reg_iops;
 496 extern const struct file_operations logfs_reg_fops;
 497 extern const struct address_space_operations logfs_reg_aops;
 498 int logfs_readpage(struct file *file, struct page *page);
 499 int logfs_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 500                 unsigned long arg);
 501 int logfs_fsync(struct file *file, struct dentry *dentry, int datasync);
 502
 503 /* gc.c */
 504 u32 get_best_cand(struct super_block *sb, struct candidate_list *list, u32 *ec);
 505 void logfs_gc_pass(struct super_block *sb);
 506 int logfs_check_areas(struct super_block *sb);
 507 int logfs_init_gc(struct super_block *sb);
 508 void logfs_cleanup_gc(struct super_block *sb);
 509
 510 /* inode.c */
 511 extern const struct super_operations logfs_super_operations;
 512 struct inode *logfs_iget(struct super_block *sb, ino_t ino);
 513 struct inode *logfs_safe_iget(struct super_block *sb, ino_t ino, int *cookie);
 514 void logfs_safe_iput(struct inode *inode, int cookie);
 515 struct inode *logfs_new_inode(struct inode *dir, int mode);
 516 struct inode *logfs_new_meta_inode(struct super_block *sb, u64 ino);
 517 struct inode *logfs_read_meta_inode(struct super_block *sb, u64 ino);
 518 int logfs_init_inode_cache(void);
 519 void logfs_destroy_inode_cache(void);
 520 void destroy_meta_inode(struct inode *inode);
 521 void logfs_set_blocks(struct inode *inode, u64 no);
 522 /* these logically belong into inode.c but actually reside in readwrite.c */
 523 int logfs_read_inode(struct inode *inode);
 524 int __logfs_write_inode(struct inode *inode, long flags);
 525 void logfs_delete_inode(struct inode *inode);
 526 void logfs_clear_inode(struct inode *inode);
 527
 528 /* journal.c */
 529 void logfs_write_anchor(struct super_block *sb);
 530 int logfs_init_journal(struct super_block *sb);
 531 void logfs_cleanup_journal(struct super_block *sb);
 532 int write_alias_journal(struct super_block *sb, u64 ino, u64 bix,
 533                 level_t level, int child_no, __be64 val);
 534 void do_logfs_journal_wl_pass(struct super_block *sb);
 535
 536 /* readwrite.c */
 537 pgoff_t logfs_pack_index(u64 bix, level_t level);
 538 void logfs_unpack_index(pgoff_t index, u64 *bix, level_t *level);
 539 int logfs_inode_write(struct inode *inode, const void *buf, size_t count,
 540                 loff_t bix, long flags, struct shadow_tree *shadow_tree);
 541 int logfs_readpage_nolock(struct page *page);
 542 int logfs_write_buf(struct inode *inode, struct page *page, long flags);
 543 int logfs_delete(struct inode *inode, pgoff_t index,
 544                 struct shadow_tree *shadow_tree);
 545 int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
 546                 gc_level_t gc_level, long flags);
 547 int logfs_is_valid_block(struct super_block *sb, u64 ofs, u64 ino, u64 bix,
 548                 gc_level_t gc_level);
 549 int logfs_truncate(struct inode *inode, u64 size);
 550 u64 logfs_seek_hole(struct inode *inode, u64 bix);
 551 u64 logfs_seek_data(struct inode *inode, u64 bix);
 552 int logfs_open_segfile(struct super_block *sb);
 553 int logfs_init_rw(struct super_block *sb);
 554 void logfs_cleanup_rw(struct super_block *sb);
 555 void logfs_add_transaction(struct inode *inode, struct logfs_transaction *ta);
 556 void logfs_del_transaction(struct inode *inode, struct logfs_transaction *ta);
 557 void logfs_write_block(struct logfs_block *block, long flags);
 558 int logfs_write_obj_aliases_pagecache(struct super_block *sb);
 559 void logfs_get_segment_entry(struct super_block *sb, u32 segno,
 560                 struct logfs_segment_entry *se);
 561 void logfs_set_segment_used(struct super_block *sb, u64 ofs, int increment);
 562 void logfs_set_segment_erased(struct super_block *sb, u32 segno, u32 ec,
 563                 gc_level_t gc_level);
 564 void logfs_set_segment_reserved(struct super_block *sb, u32 segno);
 565 void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec);
 566 struct logfs_block *__alloc_block(struct super_block *sb,
 567                 u64 ino, u64 bix, level_t level);
 568 void __free_block(struct super_block *sb, struct logfs_block *block);
 569 void btree_write_block(struct logfs_block *block);
 570 void initialize_block_counters(struct page *page, struct logfs_block *block,
 571                 __be64 *array, int page_is_empty);
 572 int logfs_exist_block(struct inode *inode, u64 bix);
 573 int get_page_reserve(struct inode *inode, struct page *page);
 574 extern struct logfs_block_ops indirect_block_ops;
 575
 576 /* segment.c */
 577 int logfs_erase_segment(struct super_block *sb, u32 ofs, int ensure_erase);
 578 int wbuf_read(struct super_block *sb, u64 ofs, size_t len, void *buf);
 579 int logfs_segment_read(struct inode *inode, struct page *page, u64 ofs, u64 bix,
 580                 level_t level);
 581 int logfs_segment_write(struct inode *inode, struct page *page,
 582                 struct logfs_shadow *shadow);
 583 int logfs_segment_delete(struct inode *inode, struct logfs_shadow *shadow);
 584 int logfs_load_object_aliases(struct super_block *sb,
 585                 struct logfs_obj_alias *oa, int count);
 586 void move_page_to_btree(struct page *page);
 587 int logfs_init_mapping(struct super_block *sb);
 588 void logfs_sync_area(struct logfs_area *area);
 589 void logfs_sync_segments(struct super_block *sb);
 590 void freeseg(struct super_block *sb, u32 segno);
 591
 592 /* area handling */
 593 int logfs_init_areas(struct super_block *sb);
 594 void logfs_cleanup_areas(struct super_block *sb);
 595 int logfs_open_area(struct logfs_area *area, size_t bytes);
 596 void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
 597                 int use_filler);
 598
 599 static inline void logfs_buf_write(struct logfs_area *area, u64 ofs,
 600                 void *buf, size_t len)
 601 {
 602         __logfs_buf_write(area, ofs, buf, len, 0);
 603 }
 604
 605 static inline void logfs_buf_recover(struct logfs_area *area, u64 ofs,
 606                 void *buf, size_t len)
 607 {
 608         __logfs_buf_write(area, ofs, buf, len, 1);
 609 }
 610
 611 /* super.c */
 612 struct page *emergency_read_begin(struct address_space *mapping, pgoff_t index);
 613 void emergency_read_end(struct page *page);
 614 void logfs_crash_dump(struct super_block *sb);
 615 void *memchr_inv(const void *s, int c, size_t n);
 616 int logfs_statfs(struct dentry *dentry, struct kstatfs *stats);
 617 int logfs_get_sb_device(struct file_system_type *type, int flags,
 618                 struct mtd_info *mtd, struct block_device *bdev,
 619                 const struct logfs_device_ops *devops, struct vfsmount *mnt);
 620 int logfs_check_ds(struct logfs_disk_super *ds);
 621 int logfs_write_sb(struct super_block *sb);
 622
 623 static inline struct logfs_super *logfs_super(struct super_block *sb)
 624 {
 625         return sb->s_fs_info;
 626 }
 627
 628 static inline struct logfs_inode *logfs_inode(struct inode *inode)
 629 {
 630         return container_of(inode, struct logfs_inode, vfs_inode);
 631 }
 632
 633 static inline void logfs_set_ro(struct super_block *sb)
 634 {
 635         logfs_super(sb)->s_flags |= LOGFS_SB_FLAG_RO;
 636 }
 637
 638 #define LOGFS_BUG(sb) do {                                      \
 639         struct super_block *__sb = sb;                          \
 640         logfs_crash_dump(__sb);                                 \
 641         logfs_super(__sb)->s_flags |= LOGFS_SB_FLAG_RO;         \
 642         BUG();                                                  \
 643 } while (0)
 644
 645 #define LOGFS_BUG_ON(condition, sb) \
 646         do { if (unlikely(condition)) LOGFS_BUG((sb)); } while (0)
 647
 648 static inline __be32 logfs_crc32(void *data, size_t len, size_t skip)
 649 {
 650         return cpu_to_be32(crc32(~0, data+skip, len-skip));
 651 }
 652
 653 static inline u8 logfs_type(struct inode *inode)
 654 {
 655         return (inode->i_mode >> 12) & 15;
 656 }
 657
 658 static inline pgoff_t logfs_index(struct super_block *sb, u64 pos)
 659 {
 660         return pos >> sb->s_blocksize_bits;
 661 }
 662
 663 static inline u64 dev_ofs(struct super_block *sb, u32 segno, u32 ofs)
 664 {
 665         return ((u64)segno << logfs_super(sb)->s_segshift) + ofs;
 666 }
 667
 668 static inline u32 seg_no(struct super_block *sb, u64 ofs)
 669 {
 670         return ofs >> logfs_super(sb)->s_segshift;
 671 }
 672
 673 static inline u32 seg_ofs(struct super_block *sb, u64 ofs)
 674 {
 675         return ofs & logfs_super(sb)->s_segmask;
 676 }
 677
 678 static inline u64 seg_align(struct super_block *sb, u64 ofs)
 679 {
 680         return ofs & ~logfs_super(sb)->s_segmask;
 681 }
 682
 683 static inline struct logfs_block *logfs_block(struct page *page)
 684 {
 685         return (void *)page->private;
 686 }
 687
 688 static inline level_t shrink_level(gc_level_t __level)
 689 {
 690         u8 level = (__force u8)__level;
 691
 692         if (level >= LOGFS_MAX_LEVELS)
 693                 level -= LOGFS_MAX_LEVELS;
 694         return (__force level_t)level;
 695 }
 696
 697 static inline gc_level_t expand_level(u64 ino, level_t __level)
 698 {
 699         u8 level = (__force u8)__level;
 700
 701         if (ino == LOGFS_INO_MASTER) {
 702                 /* ifile has seperate areas */
 703                 level += LOGFS_MAX_LEVELS;
 704         }
 705         return (__force gc_level_t)level;
 706 }
 707
 708 static inline int logfs_block_shift(struct super_block *sb, level_t level)
 709 {
 710         level = shrink_level((__force gc_level_t)level);
 711         return (__force int)level * (sb->s_blocksize_bits - 3);
 712 }
 713
 714 static inline u64 logfs_block_mask(struct super_block *sb, level_t level)
 715 {
 716         return ~0ull << logfs_block_shift(sb, level);
 717 }
 718
 719 static inline struct logfs_area *get_area(struct super_block *sb,
 720                 gc_level_t gc_level)
 721 {
 722         return logfs_super(sb)->s_area[(__force u8)gc_level];
 723 }
 724
 725 #endif