[PATCH 10/17] [LogFS] logfs.h

Joern Engel
2009-11-20T20:22:04Z

---
fs/logfs/logfs.h | 722 +++++++++++

diff --git a/fs/logfs/logfs.h b/fs/logfs/logfs.h
new file mode 100644
index 0000000..e3082ab
--- /dev/null
+++ b/fs/logfs/logfs.h
@@ -0,0 +1,722 @@
+/*
+ * 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_SEG_ALIAS 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_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
+ */
+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);
+ void (*sync)(struct super_block *sb);
+ void (*put_device)(struct super_block *sb);
+};
+
+/**
+ * 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
+ */
+struct shadow_tree {
+ struct btree_head64 new;
+ struct btree_head64 old;
+};
+
+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);
+ gc_level_t (*block_level)(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);
+};
+
+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];
+ /* 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[64];
+ 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 */
+ /*
+ * 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 file_system_type *type, int flags,
+ const char *devname, struct vfsmount *mnt);
+#else
+static inline int logfs_get_sb_bdev(struct file_system_type *type, int flags,
+ const char *devname, struct vfsmount *mnt)
+{
+ return -ENODEV;
+}
+#endif
+
+/* dev_mtd.c */
+#ifdef CONFIG_MTD
+int logfs_get_sb_mtd(struct file_system_type *type, int flags,
+ int mtdnr, struct vfsmount *mnt);
+#else
+static inline int logfs_get_sb_mtd(struct file_system_type *type, int flags,
+ int mtdnr, struct vfsmount *mnt)
+{
+ 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);
+int logfs_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+ unsigned long arg);
+int logfs_fsync(struct file *file, struct dentry *dentry, 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, int 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 destroy_meta_inode(struct inode *inode);
+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, long flags);
+void logfs_delete_inode(struct inode *inode);
+void logfs_clear_inode(struct inode *inode);
+
+/* journal.c */
+void logfs_write_anchor(struct inode *inode);
+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);
+extern struct logfs_block_ops indirect_block_ops;
+
+/* segment.c */
+int logfs_erase_segment(struct super_block *sb, u32 ofs);
+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);
+
+/* 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);
+void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
+ int use_filler);
+
+static inline void logfs_buf_write(struct logfs_area *area, u64 ofs,
+ void *buf, size_t len)
+{
+ __logfs_buf_write(area, ofs, buf, len, 0);
+}
+
+static inline void logfs_buf_recover(struct logfs_area *area, u64 ofs,
+ void *buf, size_t len)
+{
+ __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);
+void *memchr_inv(const void *s, int c, size_t n);
+int logfs_statfs(struct dentry *dentry, struct kstatfs *stats);
+int logfs_get_sb_device(struct file_system_type *type, int flags,
+ struct mtd_info *mtd, struct block_device *bdev,
+ const struct logfs_device_ops *devops, struct vfsmount *mnt);
+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 seperate 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];
+}
+
+#endif