Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / fs / logfs / logfs.h
diff --git a/kernel/fs/logfs/logfs.h b/kernel/fs/logfs/logfs.h
new file mode 100644 (file)
index 0000000..5f09376
--- /dev/null
@@ -0,0 +1,736 @@
+/*
+ * fs/logfs/logfs.h
+ *
+ * As should be obvious for Linux kernel code, license is GPLv2
+ *
+ * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
+ *
+ * Private header for logfs.
+ */
+#ifndef FS_LOGFS_LOGFS_H
+#define FS_LOGFS_LOGFS_H
+
+#undef __CHECK_ENDIAN__
+#define __CHECK_ENDIAN__
+
+#include <linux/btree.h>
+#include <linux/crc32.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/mempool.h>
+#include <linux/pagemap.h>
+#include <linux/mtd/mtd.h>
+#include "logfs_abi.h"
+
+#define LOGFS_DEBUG_SUPER      (0x0001)
+#define LOGFS_DEBUG_SEGMENT    (0x0002)
+#define LOGFS_DEBUG_JOURNAL    (0x0004)
+#define LOGFS_DEBUG_DIR                (0x0008)
+#define LOGFS_DEBUG_FILE       (0x0010)
+#define LOGFS_DEBUG_INODE      (0x0020)
+#define LOGFS_DEBUG_READWRITE  (0x0040)
+#define LOGFS_DEBUG_GC         (0x0080)
+#define LOGFS_DEBUG_GC_NOISY   (0x0100)
+#define LOGFS_DEBUG_ALIASES    (0x0200)
+#define LOGFS_DEBUG_BLOCKMOVE  (0x0400)
+#define LOGFS_DEBUG_ALL                (0xffffffff)
+
+#define LOGFS_DEBUG            (0x01)
+/*
+ * To enable specific log messages, simply define LOGFS_DEBUG to match any
+ * or all of the above.
+ */
+#ifndef LOGFS_DEBUG
+#define LOGFS_DEBUG            (0)
+#endif
+
+#define log_cond(cond, fmt, arg...) do {       \
+       if (cond)                               \
+               printk(KERN_DEBUG fmt, ##arg);  \
+} while (0)
+
+#define log_super(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_SUPER, fmt, ##arg)
+#define log_segment(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_SEGMENT, fmt, ##arg)
+#define log_journal(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_JOURNAL, fmt, ##arg)
+#define log_dir(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_DIR, fmt, ##arg)
+#define log_file(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_FILE, fmt, ##arg)
+#define log_inode(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_INODE, fmt, ##arg)
+#define log_readwrite(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_READWRITE, fmt, ##arg)
+#define log_gc(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_GC, fmt, ##arg)
+#define log_gc_noisy(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_GC_NOISY, fmt, ##arg)
+#define log_aliases(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_ALIASES, fmt, ##arg)
+#define log_blockmove(fmt, arg...) \
+       log_cond(LOGFS_DEBUG & LOGFS_DEBUG_BLOCKMOVE, fmt, ##arg)
+
+#define PG_pre_locked          PG_owner_priv_1
+#define PagePreLocked(page)    test_bit(PG_pre_locked, &(page)->flags)
+#define SetPagePreLocked(page) set_bit(PG_pre_locked, &(page)->flags)
+#define ClearPagePreLocked(page) clear_bit(PG_pre_locked, &(page)->flags)
+
+/* FIXME: This should really be somewhere in the 64bit area. */
+#define LOGFS_LINK_MAX         (1<<30)
+
+/* Read-only filesystem */
+#define LOGFS_SB_FLAG_RO       0x0001
+#define LOGFS_SB_FLAG_DIRTY    0x0002
+#define LOGFS_SB_FLAG_OBJ_ALIAS        0x0004
+#define LOGFS_SB_FLAG_SHUTDOWN 0x0008
+
+/* Write Control Flags */
+#define WF_LOCK                        0x01 /* take write lock */
+#define WF_WRITE               0x02 /* write block */
+#define WF_DELETE              0x04 /* delete old block */
+
+typedef u8 __bitwise level_t;
+typedef u8 __bitwise gc_level_t;
+
+#define LEVEL(level) ((__force level_t)(level))
+#define GC_LEVEL(gc_level) ((__force gc_level_t)(gc_level))
+
+#define SUBLEVEL(level) ( (void)((level) == LEVEL(1)), \
+               (__force level_t)((__force u8)(level) - 1) )
+
+/**
+ * struct logfs_area - area management information
+ *
+ * @a_sb:                      the superblock this area belongs to
+ * @a_is_open:                 1 if the area is currently open, else 0
+ * @a_segno:                   segment number of area
+ * @a_written_bytes:           number of bytes already written back
+ * @a_used_bytes:              number of used bytes
+ * @a_ops:                     area operations (either journal or ostore)
+ * @a_erase_count:             erase count
+ * @a_level:                   GC level
+ */
+struct logfs_area { /* a segment open for writing */
+       struct super_block *a_sb;
+       int     a_is_open;
+       u32     a_segno;
+       u32     a_written_bytes;
+       u32     a_used_bytes;
+       const struct logfs_area_ops *a_ops;
+       u32     a_erase_count;
+       gc_level_t a_level;
+};
+
+/**
+ * struct logfs_area_ops - area operations
+ *
+ * @get_free_segment:          fill area->ofs with the offset of a free segment
+ * @get_erase_count:           fill area->erase_count (needs area->ofs)
+ * @erase_segment:             erase and setup segment
+ */
+struct logfs_area_ops {
+       void    (*get_free_segment)(struct logfs_area *area);
+       void    (*get_erase_count)(struct logfs_area *area);
+       int     (*erase_segment)(struct logfs_area *area);
+};
+
+struct logfs_super;    /* forward */
+/**
+ * struct logfs_device_ops - device access operations
+ *
+ * @readpage:                  read one page (mm page)
+ * @writeseg:                  write one segment.  may be a partial segment
+ * @erase:                     erase one segment
+ * @read:                      read from the device
+ * @erase:                     erase part of the device
+ * @can_write_buf:             decide whether wbuf can be written to ofs
+ */
+struct logfs_device_ops {
+       struct page *(*find_first_sb)(struct super_block *sb, u64 *ofs);
+       struct page *(*find_last_sb)(struct super_block *sb, u64 *ofs);
+       int (*write_sb)(struct super_block *sb, struct page *page);
+       int (*readpage)(void *_sb, struct page *page);
+       void (*writeseg)(struct super_block *sb, u64 ofs, size_t len);
+       int (*erase)(struct super_block *sb, loff_t ofs, size_t len,
+                       int ensure_write);
+       int (*can_write_buf)(struct super_block *sb, u64 ofs);
+       void (*sync)(struct super_block *sb);
+       void (*put_device)(struct logfs_super *s);
+};
+
+/**
+ * struct candidate_list - list of similar candidates
+ */
+struct candidate_list {
+       struct rb_root rb_tree;
+       int count;
+       int maxcount;
+       int sort_by_ec;
+};
+
+/**
+ * struct gc_candidate - "candidate" segment to be garbage collected next
+ *
+ * @list:                      list (either free of low)
+ * @segno:                     segment number
+ * @valid:                     number of valid bytes
+ * @erase_count:               erase count of segment
+ * @dist:                      distance from tree root
+ *
+ * Candidates can be on two lists.  The free list contains electees rather
+ * than candidates - segments that no longer contain any valid data.  The
+ * low list contains candidates to be picked for GC.  It should be kept
+ * short.  It is not required to always pick a perfect candidate.  In the
+ * worst case GC will have to move more data than absolutely necessary.
+ */
+struct gc_candidate {
+       struct rb_node rb_node;
+       struct candidate_list *list;
+       u32     segno;
+       u32     valid;
+       u32     erase_count;
+       u8      dist;
+};
+
+/**
+ * struct logfs_journal_entry - temporary structure used during journal scan
+ *
+ * @used:
+ * @version:                   normalized version
+ * @len:                       length
+ * @offset:                    offset
+ */
+struct logfs_journal_entry {
+       int used;
+       s16 version;
+       u16 len;
+       u16 datalen;
+       u64 offset;
+};
+
+enum transaction_state {
+       CREATE_1 = 1,
+       CREATE_2,
+       UNLINK_1,
+       UNLINK_2,
+       CROSS_RENAME_1,
+       CROSS_RENAME_2,
+       TARGET_RENAME_1,
+       TARGET_RENAME_2,
+       TARGET_RENAME_3
+};
+
+/**
+ * struct logfs_transaction - essential fields to support atomic dirops
+ *
+ * @ino:                       target inode
+ * @dir:                       inode of directory containing dentry
+ * @pos:                       pos of dentry in directory
+ */
+struct logfs_transaction {
+       enum transaction_state state;
+       u64      ino;
+       u64      dir;
+       u64      pos;
+};
+
+/**
+ * struct logfs_shadow - old block in the shadow of a not-yet-committed new one
+ * @old_ofs:                   offset of old block on medium
+ * @new_ofs:                   offset of new block on medium
+ * @ino:                       inode number
+ * @bix:                       block index
+ * @old_len:                   size of old block, including header
+ * @new_len:                   size of new block, including header
+ * @level:                     block level
+ */
+struct logfs_shadow {
+       u64 old_ofs;
+       u64 new_ofs;
+       u64 ino;
+       u64 bix;
+       int old_len;
+       int new_len;
+       gc_level_t gc_level;
+};
+
+/**
+ * struct shadow_tree
+ * @new:                       shadows where old_ofs==0, indexed by new_ofs
+ * @old:                       shadows where old_ofs!=0, indexed by old_ofs
+ * @segment_map:               bitfield of segments containing shadows
+ * @no_shadowed_segment:       number of segments containing shadows
+ */
+struct shadow_tree {
+       struct btree_head64 new;
+       struct btree_head64 old;
+       struct btree_head32 segment_map;
+       int no_shadowed_segments;
+};
+
+struct object_alias_item {
+       struct list_head list;
+       __be64 val;
+       int child_no;
+};
+
+/**
+ * struct logfs_block - contains any block state
+ * @type:                      indirect block or inode
+ * @full:                      number of fully populated children
+ * @partial:                   number of partially populated children
+ *
+ * Most blocks are directly represented by page cache pages.  But when a block
+ * becomes dirty, is part of a transaction, contains aliases or is otherwise
+ * special, a struct logfs_block is allocated to track the additional state.
+ * Inodes are very similar to indirect blocks, so they can also get one of
+ * these structures added when appropriate.
+ */
+#define BLOCK_INDIRECT 1       /* Indirect block */
+#define BLOCK_INODE    2       /* Inode */
+struct logfs_block_ops;
+struct logfs_block {
+       struct list_head alias_list;
+       struct list_head item_list;
+       struct super_block *sb;
+       u64 ino;
+       u64 bix;
+       level_t level;
+       struct page *page;
+       struct inode *inode;
+       struct logfs_transaction *ta;
+       unsigned long alias_map[LOGFS_BLOCK_FACTOR / BITS_PER_LONG];
+       struct logfs_block_ops *ops;
+       int full;
+       int partial;
+       int reserved_bytes;
+};
+
+typedef int write_alias_t(struct super_block *sb, u64 ino, u64 bix,
+               level_t level, int child_no, __be64 val);
+struct logfs_block_ops {
+       void    (*write_block)(struct logfs_block *block);
+       void    (*free_block)(struct super_block *sb, struct logfs_block*block);
+       int     (*write_alias)(struct super_block *sb,
+                       struct logfs_block *block,
+                       write_alias_t *write_one_alias);
+};
+
+#define MAX_JOURNAL_ENTRIES 256
+
+struct logfs_super {
+       struct mtd_info *s_mtd;                 /* underlying device */
+       struct block_device *s_bdev;            /* underlying device */
+       const struct logfs_device_ops *s_devops;/* device access */
+       struct inode    *s_master_inode;        /* inode file */
+       struct inode    *s_segfile_inode;       /* segment file */
+       struct inode *s_mapping_inode;          /* device mapping */
+       atomic_t s_pending_writes;              /* outstanting bios */
+       long     s_flags;
+       mempool_t *s_btree_pool;                /* for btree nodes */
+       mempool_t *s_alias_pool;                /* aliases in segment.c */
+       u64      s_feature_incompat;
+       u64      s_feature_ro_compat;
+       u64      s_feature_compat;
+       u64      s_feature_flags;
+       u64      s_sb_ofs[2];
+       struct page *s_erase_page;              /* for dev_bdev.c */
+       /* alias.c fields */
+       struct btree_head32 s_segment_alias;    /* remapped segments */
+       int      s_no_object_aliases;
+       struct list_head s_object_alias;        /* remapped objects */
+       struct btree_head128 s_object_alias_tree; /* remapped objects */
+       struct mutex s_object_alias_mutex;
+       /* dir.c fields */
+       struct mutex s_dirop_mutex;             /* for creat/unlink/rename */
+       u64      s_victim_ino;                  /* used for atomic dir-ops */
+       u64      s_rename_dir;                  /* source directory ino */
+       u64      s_rename_pos;                  /* position of source dd */
+       /* gc.c fields */
+       long     s_segsize;                     /* size of a segment */
+       int      s_segshift;                    /* log2 of segment size */
+       long     s_segmask;                     /* 1 << s_segshift - 1 */
+       long     s_no_segs;                     /* segments on device */
+       long     s_no_journal_segs;             /* segments used for journal */
+       long     s_no_blocks;                   /* blocks per segment */
+       long     s_writesize;                   /* minimum write size */
+       int      s_writeshift;                  /* log2 of write size */
+       u64      s_size;                        /* filesystem size */
+       struct logfs_area *s_area[LOGFS_NO_AREAS];      /* open segment array */
+       u64      s_gec;                         /* global erase count */
+       u64      s_wl_gec_ostore;               /* time of last wl event */
+       u64      s_wl_gec_journal;              /* time of last wl event */
+       u64      s_sweeper;                     /* current sweeper pos */
+       u8       s_ifile_levels;                /* max level of ifile */
+       u8       s_iblock_levels;               /* max level of regular files */
+       u8       s_data_levels;                 /* # of segments to leaf block*/
+       u8       s_total_levels;                /* sum of above three */
+       struct btree_head32 s_cand_tree;        /* all candidates */
+       struct candidate_list s_free_list;      /* 100% free segments */
+       struct candidate_list s_reserve_list;   /* Bad segment reserve */
+       struct candidate_list s_low_list[LOGFS_NO_AREAS];/* good candidates */
+       struct candidate_list s_ec_list;        /* wear level candidates */
+       struct btree_head32 s_reserved_segments;/* sb, journal, bad, etc. */
+       /* inode.c fields */
+       u64      s_last_ino;                    /* highest ino used */
+       long     s_inos_till_wrap;
+       u32      s_generation;                  /* i_generation for new files */
+       struct list_head s_freeing_list;        /* inodes being freed */
+       /* journal.c fields */
+       struct mutex s_journal_mutex;
+       void    *s_je;                          /* journal entry to compress */
+       void    *s_compressed_je;               /* block to write to journal */
+       u32      s_journal_seg[LOGFS_JOURNAL_SEGS]; /* journal segments */
+       u32      s_journal_ec[LOGFS_JOURNAL_SEGS]; /* journal erasecounts */
+       u64      s_last_version;
+       struct logfs_area *s_journal_area;      /* open journal segment */
+       __be64  s_je_array[MAX_JOURNAL_ENTRIES];
+       int     s_no_je;
+
+       int      s_sum_index;                   /* for the 12 summaries */
+       struct shadow_tree s_shadow_tree;
+       int      s_je_fill;                     /* index of current je */
+       /* readwrite.c fields */
+       struct mutex s_write_mutex;
+       int      s_lock_count;
+       mempool_t *s_block_pool;                /* struct logfs_block pool */
+       mempool_t *s_shadow_pool;               /* struct logfs_shadow pool */
+       struct list_head s_writeback_list;      /* writeback pages */
+       /*
+        * Space accounting:
+        * - s_used_bytes specifies space used to store valid data objects.
+        * - s_dirty_used_bytes is space used to store non-committed data
+        *   objects.  Those objects have already been written themselves,
+        *   but they don't become valid until all indirect blocks up to the
+        *   journal have been written as well.
+        * - s_dirty_free_bytes is space used to store the old copy of a
+        *   replaced object, as long as the replacement is non-committed.
+        *   In other words, it is the amount of space freed when all dirty
+        *   blocks are written back.
+        * - s_free_bytes is the amount of free space available for any
+        *   purpose.
+        * - s_root_reserve is the amount of free space available only to
+        *   the root user.  Non-privileged users can no longer write once
+        *   this watermark has been reached.
+        * - s_speed_reserve is space which remains unused to speed up
+        *   garbage collection performance.
+        * - s_dirty_pages is the space reserved for currently dirty pages.
+        *   It is a pessimistic estimate, so some/most will get freed on
+        *   page writeback.
+        *
+        * s_used_bytes + s_free_bytes + s_speed_reserve = total usable size
+        */
+       u64      s_free_bytes;
+       u64      s_used_bytes;
+       u64      s_dirty_free_bytes;
+       u64      s_dirty_used_bytes;
+       u64      s_root_reserve;
+       u64      s_speed_reserve;
+       u64      s_dirty_pages;
+       /* Bad block handling:
+        * - s_bad_seg_reserve is a number of segments usually kept
+        *   free.  When encountering bad blocks, the affected segment's data
+        *   is _temporarily_ moved to a reserved segment.
+        * - s_bad_segments is the number of known bad segments.
+        */
+       u32      s_bad_seg_reserve;
+       u32      s_bad_segments;
+};
+
+/**
+ * struct logfs_inode - in-memory inode
+ *
+ * @vfs_inode:                 struct inode
+ * @li_data:                   data pointers
+ * @li_used_bytes:             number of used bytes
+ * @li_freeing_list:           used to track inodes currently being freed
+ * @li_flags:                  inode flags
+ * @li_refcount:               number of internal (GC-induced) references
+ */
+struct logfs_inode {
+       struct inode vfs_inode;
+       u64     li_data[LOGFS_EMBEDDED_FIELDS];
+       u64     li_used_bytes;
+       struct list_head li_freeing_list;
+       struct logfs_block *li_block;
+       u32     li_flags;
+       u8      li_height;
+       int     li_refcount;
+};
+
+#define journal_for_each(__i) for (__i = 0; __i < LOGFS_JOURNAL_SEGS; __i++)
+#define for_each_area(__i) for (__i = 0; __i < LOGFS_NO_AREAS; __i++)
+#define for_each_area_down(__i) for (__i = LOGFS_NO_AREAS - 1; __i >= 0; __i--)
+
+/* compr.c */
+int logfs_compress(void *in, void *out, size_t inlen, size_t outlen);
+int logfs_uncompress(void *in, void *out, size_t inlen, size_t outlen);
+int __init logfs_compr_init(void);
+void logfs_compr_exit(void);
+
+/* dev_bdev.c */
+#ifdef CONFIG_BLOCK
+int logfs_get_sb_bdev(struct logfs_super *s,
+               struct file_system_type *type,
+               const char *devname);
+#else
+static inline int logfs_get_sb_bdev(struct logfs_super *s,
+               struct file_system_type *type,
+               const char *devname)
+{
+       return -ENODEV;
+}
+#endif
+
+/* dev_mtd.c */
+#ifdef CONFIG_MTD
+int logfs_get_sb_mtd(struct logfs_super *s, int mtdnr);
+#else
+static inline int logfs_get_sb_mtd(struct logfs_super *s, int mtdnr)
+{
+       return -ENODEV;
+}
+#endif
+
+/* dir.c */
+extern const struct inode_operations logfs_symlink_iops;
+extern const struct inode_operations logfs_dir_iops;
+extern const struct file_operations logfs_dir_fops;
+int logfs_replay_journal(struct super_block *sb);
+
+/* file.c */
+extern const struct inode_operations logfs_reg_iops;
+extern const struct file_operations logfs_reg_fops;
+extern const struct address_space_operations logfs_reg_aops;
+int logfs_readpage(struct file *file, struct page *page);
+long logfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+int logfs_fsync(struct file *file, loff_t start, loff_t end, int datasync);
+
+/* gc.c */
+u32 get_best_cand(struct super_block *sb, struct candidate_list *list, u32 *ec);
+void logfs_gc_pass(struct super_block *sb);
+int logfs_check_areas(struct super_block *sb);
+int logfs_init_gc(struct super_block *sb);
+void logfs_cleanup_gc(struct super_block *sb);
+
+/* inode.c */
+extern const struct super_operations logfs_super_operations;
+struct inode *logfs_iget(struct super_block *sb, ino_t ino);
+struct inode *logfs_safe_iget(struct super_block *sb, ino_t ino, int *cookie);
+void logfs_safe_iput(struct inode *inode, int cookie);
+struct inode *logfs_new_inode(struct inode *dir, umode_t mode);
+struct inode *logfs_new_meta_inode(struct super_block *sb, u64 ino);
+struct inode *logfs_read_meta_inode(struct super_block *sb, u64 ino);
+int logfs_init_inode_cache(void);
+void logfs_destroy_inode_cache(void);
+void logfs_set_blocks(struct inode *inode, u64 no);
+/* these logically belong into inode.c but actually reside in readwrite.c */
+int logfs_read_inode(struct inode *inode);
+int __logfs_write_inode(struct inode *inode, struct page *, long flags);
+void logfs_evict_inode(struct inode *inode);
+
+/* journal.c */
+void logfs_write_anchor(struct super_block *sb);
+int logfs_init_journal(struct super_block *sb);
+void logfs_cleanup_journal(struct super_block *sb);
+int write_alias_journal(struct super_block *sb, u64 ino, u64 bix,
+               level_t level, int child_no, __be64 val);
+void do_logfs_journal_wl_pass(struct super_block *sb);
+
+/* readwrite.c */
+pgoff_t logfs_pack_index(u64 bix, level_t level);
+void logfs_unpack_index(pgoff_t index, u64 *bix, level_t *level);
+int logfs_inode_write(struct inode *inode, const void *buf, size_t count,
+               loff_t bix, long flags, struct shadow_tree *shadow_tree);
+int logfs_readpage_nolock(struct page *page);
+int logfs_write_buf(struct inode *inode, struct page *page, long flags);
+int logfs_delete(struct inode *inode, pgoff_t index,
+               struct shadow_tree *shadow_tree);
+int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
+               gc_level_t gc_level, long flags);
+int logfs_is_valid_block(struct super_block *sb, u64 ofs, u64 ino, u64 bix,
+               gc_level_t gc_level);
+int logfs_truncate(struct inode *inode, u64 size);
+u64 logfs_seek_hole(struct inode *inode, u64 bix);
+u64 logfs_seek_data(struct inode *inode, u64 bix);
+int logfs_open_segfile(struct super_block *sb);
+int logfs_init_rw(struct super_block *sb);
+void logfs_cleanup_rw(struct super_block *sb);
+void logfs_add_transaction(struct inode *inode, struct logfs_transaction *ta);
+void logfs_del_transaction(struct inode *inode, struct logfs_transaction *ta);
+void logfs_write_block(struct logfs_block *block, long flags);
+int logfs_write_obj_aliases_pagecache(struct super_block *sb);
+void logfs_get_segment_entry(struct super_block *sb, u32 segno,
+               struct logfs_segment_entry *se);
+void logfs_set_segment_used(struct super_block *sb, u64 ofs, int increment);
+void logfs_set_segment_erased(struct super_block *sb, u32 segno, u32 ec,
+               gc_level_t gc_level);
+void logfs_set_segment_reserved(struct super_block *sb, u32 segno);
+void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec);
+struct logfs_block *__alloc_block(struct super_block *sb,
+               u64 ino, u64 bix, level_t level);
+void __free_block(struct super_block *sb, struct logfs_block *block);
+void btree_write_block(struct logfs_block *block);
+void initialize_block_counters(struct page *page, struct logfs_block *block,
+               __be64 *array, int page_is_empty);
+int logfs_exist_block(struct inode *inode, u64 bix);
+int get_page_reserve(struct inode *inode, struct page *page);
+void logfs_get_wblocks(struct super_block *sb, struct page *page, int lock);
+void logfs_put_wblocks(struct super_block *sb, struct page *page, int lock);
+extern struct logfs_block_ops indirect_block_ops;
+
+/* segment.c */
+int logfs_erase_segment(struct super_block *sb, u32 ofs, int ensure_erase);
+int wbuf_read(struct super_block *sb, u64 ofs, size_t len, void *buf);
+int logfs_segment_read(struct inode *inode, struct page *page, u64 ofs, u64 bix,
+               level_t level);
+int logfs_segment_write(struct inode *inode, struct page *page,
+               struct logfs_shadow *shadow);
+int logfs_segment_delete(struct inode *inode, struct logfs_shadow *shadow);
+int logfs_load_object_aliases(struct super_block *sb,
+               struct logfs_obj_alias *oa, int count);
+void move_page_to_btree(struct page *page);
+int logfs_init_mapping(struct super_block *sb);
+void logfs_sync_area(struct logfs_area *area);
+void logfs_sync_segments(struct super_block *sb);
+void freeseg(struct super_block *sb, u32 segno);
+void free_areas(struct super_block *sb);
+
+/* area handling */
+int logfs_init_areas(struct super_block *sb);
+void logfs_cleanup_areas(struct super_block *sb);
+int logfs_open_area(struct logfs_area *area, size_t bytes);
+int __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
+               int use_filler);
+
+static inline int logfs_buf_write(struct logfs_area *area, u64 ofs,
+               void *buf, size_t len)
+{
+       return __logfs_buf_write(area, ofs, buf, len, 0);
+}
+
+static inline int logfs_buf_recover(struct logfs_area *area, u64 ofs,
+               void *buf, size_t len)
+{
+       return __logfs_buf_write(area, ofs, buf, len, 1);
+}
+
+/* super.c */
+struct page *emergency_read_begin(struct address_space *mapping, pgoff_t index);
+void emergency_read_end(struct page *page);
+void logfs_crash_dump(struct super_block *sb);
+int logfs_statfs(struct dentry *dentry, struct kstatfs *stats);
+int logfs_check_ds(struct logfs_disk_super *ds);
+int logfs_write_sb(struct super_block *sb);
+
+static inline struct logfs_super *logfs_super(struct super_block *sb)
+{
+       return sb->s_fs_info;
+}
+
+static inline struct logfs_inode *logfs_inode(struct inode *inode)
+{
+       return container_of(inode, struct logfs_inode, vfs_inode);
+}
+
+static inline void logfs_set_ro(struct super_block *sb)
+{
+       logfs_super(sb)->s_flags |= LOGFS_SB_FLAG_RO;
+}
+
+#define LOGFS_BUG(sb) do {                                     \
+       struct super_block *__sb = sb;                          \
+       logfs_crash_dump(__sb);                                 \
+       logfs_super(__sb)->s_flags |= LOGFS_SB_FLAG_RO;         \
+       BUG();                                                  \
+} while (0)
+
+#define LOGFS_BUG_ON(condition, sb) \
+       do { if (unlikely(condition)) LOGFS_BUG((sb)); } while (0)
+
+static inline __be32 logfs_crc32(void *data, size_t len, size_t skip)
+{
+       return cpu_to_be32(crc32(~0, data+skip, len-skip));
+}
+
+static inline u8 logfs_type(struct inode *inode)
+{
+       return (inode->i_mode >> 12) & 15;
+}
+
+static inline pgoff_t logfs_index(struct super_block *sb, u64 pos)
+{
+       return pos >> sb->s_blocksize_bits;
+}
+
+static inline u64 dev_ofs(struct super_block *sb, u32 segno, u32 ofs)
+{
+       return ((u64)segno << logfs_super(sb)->s_segshift) + ofs;
+}
+
+static inline u32 seg_no(struct super_block *sb, u64 ofs)
+{
+       return ofs >> logfs_super(sb)->s_segshift;
+}
+
+static inline u32 seg_ofs(struct super_block *sb, u64 ofs)
+{
+       return ofs & logfs_super(sb)->s_segmask;
+}
+
+static inline u64 seg_align(struct super_block *sb, u64 ofs)
+{
+       return ofs & ~logfs_super(sb)->s_segmask;
+}
+
+static inline struct logfs_block *logfs_block(struct page *page)
+{
+       return (void *)page->private;
+}
+
+static inline level_t shrink_level(gc_level_t __level)
+{
+       u8 level = (__force u8)__level;
+
+       if (level >= LOGFS_MAX_LEVELS)
+               level -= LOGFS_MAX_LEVELS;
+       return (__force level_t)level;
+}
+
+static inline gc_level_t expand_level(u64 ino, level_t __level)
+{
+       u8 level = (__force u8)__level;
+
+       if (ino == LOGFS_INO_MASTER) {
+               /* ifile has separate areas */
+               level += LOGFS_MAX_LEVELS;
+       }
+       return (__force gc_level_t)level;
+}
+
+static inline int logfs_block_shift(struct super_block *sb, level_t level)
+{
+       level = shrink_level((__force gc_level_t)level);
+       return (__force int)level * (sb->s_blocksize_bits - 3);
+}
+
+static inline u64 logfs_block_mask(struct super_block *sb, level_t level)
+{
+       return ~0ull << logfs_block_shift(sb, level);
+}
+
+static inline struct logfs_area *get_area(struct super_block *sb,
+               gc_level_t gc_level)
+{
+       return logfs_super(sb)->s_area[(__force u8)gc_level];
+}
+
+static inline void logfs_mempool_destroy(mempool_t *pool)
+{
+       if (pool)
+               mempool_destroy(pool);
+}
+
+#endif