f2fs: clean up the do_submit_bio flow

[mirror_ubuntu-bionic-kernel.git] / fs / f2fs / f2fs.h

/*
 * fs/f2fs/f2fs.h
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef _LINUX_F2FS_H
#define _LINUX_F2FS_H

#include <linux/types.h>
#include <linux/page-flags.h>
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/crc32.h>
#include <linux/magic.h>
#include <linux/kobject.h>
#include <linux/sched.h>

#ifdef CONFIG_F2FS_CHECK_FS
#define f2fs_bug_on(condition)  BUG_ON(condition)
#else
#define f2fs_bug_on(condition)
#endif

/*
 * For mount options
 */
#define F2FS_MOUNT_BG_GC                0x00000001
#define F2FS_MOUNT_DISABLE_ROLL_FORWARD 0x00000002
#define F2FS_MOUNT_DISCARD              0x00000004
#define F2FS_MOUNT_NOHEAP               0x00000008
#define F2FS_MOUNT_XATTR_USER           0x00000010
#define F2FS_MOUNT_POSIX_ACL            0x00000020
#define F2FS_MOUNT_DISABLE_EXT_IDENTIFY 0x00000040
#define F2FS_MOUNT_INLINE_XATTR         0x00000080

#define clear_opt(sbi, option)  (sbi->mount_opt.opt &= ~F2FS_MOUNT_##option)
#define set_opt(sbi, option)    (sbi->mount_opt.opt |= F2FS_MOUNT_##option)
#define test_opt(sbi, option)   (sbi->mount_opt.opt & F2FS_MOUNT_##option)

#define ver_after(a, b) (typecheck(unsigned long long, a) &&            \
                typecheck(unsigned long long, b) &&                     \
                ((long long)((a) - (b)) > 0))

typedef u32 block_t;    /*
                         * should not change u32, since it is the on-disk block
                         * address format, __le32.
                         */
typedef u32 nid_t;

struct f2fs_mount_info {
        unsigned int    opt;
};

#define CRCPOLY_LE 0xedb88320

static inline __u32 f2fs_crc32(void *buf, size_t len)
{
        unsigned char *p = (unsigned char *)buf;
        __u32 crc = F2FS_SUPER_MAGIC;
        int i;

        while (len--) {
                crc ^= *p++;
                for (i = 0; i < 8; i++)
                        crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
        }
        return crc;
}

static inline bool f2fs_crc_valid(__u32 blk_crc, void *buf, size_t buf_size)
{
        return f2fs_crc32(buf, buf_size) == blk_crc;
}

/*
 * For checkpoint manager
 */
enum {
        NAT_BITMAP,
        SIT_BITMAP
};

/* for the list of orphan inodes */
struct orphan_inode_entry {
        struct list_head list;  /* list head */
        nid_t ino;              /* inode number */
};

/* for the list of directory inodes */
struct dir_inode_entry {
        struct list_head list;  /* list head */
        struct inode *inode;    /* vfs inode pointer */
};

/* for the list of blockaddresses to be discarded */
struct discard_entry {
        struct list_head list;  /* list head */
        block_t blkaddr;        /* block address to be discarded */
        int len;                /* # of consecutive blocks of the discard */
};

/* for the list of fsync inodes, used only during recovery */
struct fsync_inode_entry {
        struct list_head list;  /* list head */
        struct inode *inode;    /* vfs inode pointer */
        block_t blkaddr;        /* block address locating the last inode */
};

#define nats_in_cursum(sum)             (le16_to_cpu(sum->n_nats))
#define sits_in_cursum(sum)             (le16_to_cpu(sum->n_sits))

#define nat_in_journal(sum, i)          (sum->nat_j.entries[i].ne)
#define nid_in_journal(sum, i)          (sum->nat_j.entries[i].nid)
#define sit_in_journal(sum, i)          (sum->sit_j.entries[i].se)
#define segno_in_journal(sum, i)        (sum->sit_j.entries[i].segno)

static inline int update_nats_in_cursum(struct f2fs_summary_block *rs, int i)
{
        int before = nats_in_cursum(rs);
        rs->n_nats = cpu_to_le16(before + i);
        return before;
}

static inline int update_sits_in_cursum(struct f2fs_summary_block *rs, int i)
{
        int before = sits_in_cursum(rs);
        rs->n_sits = cpu_to_le16(before + i);
        return before;
}

/*
 * ioctl commands
 */
#define F2FS_IOC_GETFLAGS               FS_IOC_GETFLAGS
#define F2FS_IOC_SETFLAGS               FS_IOC_SETFLAGS

#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/*
 * ioctl commands in 32 bit emulation
 */
#define F2FS_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
#define F2FS_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
#endif

/*
 * For INODE and NODE manager
 */
/*
 * XATTR_NODE_OFFSET stores xattrs to one node block per file keeping -1
 * as its node offset to distinguish from index node blocks.
 * But some bits are used to mark the node block.
 */
#define XATTR_NODE_OFFSET       ((((unsigned int)-1) << OFFSET_BIT_SHIFT) \
                                >> OFFSET_BIT_SHIFT)
enum {
        ALLOC_NODE,                     /* allocate a new node page if needed */
        LOOKUP_NODE,                    /* look up a node without readahead */
        LOOKUP_NODE_RA,                 /*
                                         * look up a node with readahead called
                                         * by get_datablock_ro.
                                         */
};

#define F2FS_LINK_MAX           32000   /* maximum link count per file */

/* for in-memory extent cache entry */
struct extent_info {
        rwlock_t ext_lock;      /* rwlock for consistency */
        unsigned int fofs;      /* start offset in a file */
        u32 blk_addr;           /* start block address of the extent */
        unsigned int len;       /* length of the extent */
};

/*
 * i_advise uses FADVISE_XXX_BIT. We can add additional hints later.
 */
#define FADVISE_COLD_BIT        0x01
#define FADVISE_LOST_PINO_BIT   0x02

struct f2fs_inode_info {
        struct inode vfs_inode;         /* serve a vfs inode */
        unsigned long i_flags;          /* keep an inode flags for ioctl */
        unsigned char i_advise;         /* use to give file attribute hints */
        unsigned int i_current_depth;   /* use only in directory structure */
        unsigned int i_pino;            /* parent inode number */
        umode_t i_acl_mode;             /* keep file acl mode temporarily */

        /* Use below internally in f2fs*/
        unsigned long flags;            /* use to pass per-file flags */
        atomic_t dirty_dents;           /* # of dirty dentry pages */
        f2fs_hash_t chash;              /* hash value of given file name */
        unsigned int clevel;            /* maximum level of given file name */
        nid_t i_xattr_nid;              /* node id that contains xattrs */
        unsigned long long xattr_ver;   /* cp version of xattr modification */
        struct extent_info ext;         /* in-memory extent cache entry */
};

static inline void get_extent_info(struct extent_info *ext,
                                        struct f2fs_extent i_ext)
{
        write_lock(&ext->ext_lock);
        ext->fofs = le32_to_cpu(i_ext.fofs);
        ext->blk_addr = le32_to_cpu(i_ext.blk_addr);
        ext->len = le32_to_cpu(i_ext.len);
        write_unlock(&ext->ext_lock);
}

static inline void set_raw_extent(struct extent_info *ext,
                                        struct f2fs_extent *i_ext)
{
        read_lock(&ext->ext_lock);
        i_ext->fofs = cpu_to_le32(ext->fofs);
        i_ext->blk_addr = cpu_to_le32(ext->blk_addr);
        i_ext->len = cpu_to_le32(ext->len);
        read_unlock(&ext->ext_lock);
}

struct f2fs_nm_info {
        block_t nat_blkaddr;            /* base disk address of NAT */
        nid_t max_nid;                  /* maximum possible node ids */
        nid_t next_scan_nid;            /* the next nid to be scanned */

        /* NAT cache management */
        struct radix_tree_root nat_root;/* root of the nat entry cache */
        rwlock_t nat_tree_lock;         /* protect nat_tree_lock */
        unsigned int nat_cnt;           /* the # of cached nat entries */
        struct list_head nat_entries;   /* cached nat entry list (clean) */
        struct list_head dirty_nat_entries; /* cached nat entry list (dirty) */

        /* free node ids management */
        struct list_head free_nid_list; /* a list for free nids */
        spinlock_t free_nid_list_lock;  /* protect free nid list */
        unsigned int fcnt;              /* the number of free node id */
        struct mutex build_lock;        /* lock for build free nids */

        /* for checkpoint */
        char *nat_bitmap;               /* NAT bitmap pointer */
        int bitmap_size;                /* bitmap size */
};

/*
 * this structure is used as one of function parameters.
 * all the information are dedicated to a given direct node block determined
 * by the data offset in a file.
 */
struct dnode_of_data {
        struct inode *inode;            /* vfs inode pointer */
        struct page *inode_page;        /* its inode page, NULL is possible */
        struct page *node_page;         /* cached direct node page */
        nid_t nid;                      /* node id of the direct node block */
        unsigned int ofs_in_node;       /* data offset in the node page */
        bool inode_page_locked;         /* inode page is locked or not */
        block_t data_blkaddr;           /* block address of the node block */
};

static inline void set_new_dnode(struct dnode_of_data *dn, struct inode *inode,
                struct page *ipage, struct page *npage, nid_t nid)
{
        memset(dn, 0, sizeof(*dn));
        dn->inode = inode;
        dn->inode_page = ipage;
        dn->node_page = npage;
        dn->nid = nid;
}

/*
 * For SIT manager
 *
 * By default, there are 6 active log areas across the whole main area.
 * When considering hot and cold data separation to reduce cleaning overhead,
 * we split 3 for data logs and 3 for node logs as hot, warm, and cold types,
 * respectively.
 * In the current design, you should not change the numbers intentionally.
 * Instead, as a mount option such as active_logs=x, you can use 2, 4, and 6
 * logs individually according to the underlying devices. (default: 6)
 * Just in case, on-disk layout covers maximum 16 logs that consist of 8 for
 * data and 8 for node logs.
 */
#define NR_CURSEG_DATA_TYPE     (3)
#define NR_CURSEG_NODE_TYPE     (3)
#define NR_CURSEG_TYPE  (NR_CURSEG_DATA_TYPE + NR_CURSEG_NODE_TYPE)

enum {
        CURSEG_HOT_DATA = 0,    /* directory entry blocks */
        CURSEG_WARM_DATA,       /* data blocks */
        CURSEG_COLD_DATA,       /* multimedia or GCed data blocks */
        CURSEG_HOT_NODE,        /* direct node blocks of directory files */
        CURSEG_WARM_NODE,       /* direct node blocks of normal files */
        CURSEG_COLD_NODE,       /* indirect node blocks */
        NO_CHECK_TYPE
};

struct f2fs_sm_info {
        struct sit_info *sit_info;              /* whole segment information */
        struct free_segmap_info *free_info;     /* free segment information */
        struct dirty_seglist_info *dirty_info;  /* dirty segment information */
        struct curseg_info *curseg_array;       /* active segment information */

        struct list_head wblist_head;   /* list of under-writeback pages */
        spinlock_t wblist_lock;         /* lock for checkpoint */

        block_t seg0_blkaddr;           /* block address of 0'th segment */
        block_t main_blkaddr;           /* start block address of main area */
        block_t ssa_blkaddr;            /* start block address of SSA area */

        unsigned int segment_count;     /* total # of segments */
        unsigned int main_segments;     /* # of segments in main area */
        unsigned int reserved_segments; /* # of reserved segments */
        unsigned int ovp_segments;      /* # of overprovision segments */

        /* a threshold to reclaim prefree segments */
        unsigned int rec_prefree_segments;

        /* for small discard management */
        struct list_head discard_list;          /* 4KB discard list */
        int nr_discards;                        /* # of discards in the list */
        int max_discards;                       /* max. discards to be issued */
};

/*
 * For superblock
 */
/*
 * COUNT_TYPE for monitoring
 *
 * f2fs monitors the number of several block types such as on-writeback,
 * dirty dentry blocks, dirty node blocks, and dirty meta blocks.
 */
enum count_type {
        F2FS_WRITEBACK,
        F2FS_DIRTY_DENTS,
        F2FS_DIRTY_NODES,
        F2FS_DIRTY_META,
        NR_COUNT_TYPE,
};

/*
 * The below are the page types of bios used in submti_bio().
 * The available types are:
 * DATA                 User data pages. It operates as async mode.
 * NODE                 Node pages. It operates as async mode.
 * META                 FS metadata pages such as SIT, NAT, CP.
 * NR_PAGE_TYPE         The number of page types.
 * META_FLUSH           Make sure the previous pages are written
 *                      with waiting the bio's completion
 * ...                  Only can be used with META.
 */
#define PAGE_TYPE_OF_BIO(type)  ((type) > META ? META : (type))
enum page_type {
        DATA,
        NODE,
        META,
        NR_PAGE_TYPE,
        META_FLUSH,
};

struct f2fs_sb_info {
        struct super_block *sb;                 /* pointer to VFS super block */
        struct proc_dir_entry *s_proc;          /* proc entry */
        struct buffer_head *raw_super_buf;      /* buffer head of raw sb */
        struct f2fs_super_block *raw_super;     /* raw super block pointer */
        int s_dirty;                            /* dirty flag for checkpoint */

        /* for node-related operations */
        struct f2fs_nm_info *nm_info;           /* node manager */
        struct inode *node_inode;               /* cache node blocks */

        /* for segment-related operations */
        struct f2fs_sm_info *sm_info;           /* segment manager */
        struct bio *bio[NR_PAGE_TYPE];          /* bios to merge */
        sector_t last_block_in_bio[NR_PAGE_TYPE];       /* last block number */
        struct rw_semaphore bio_sem;            /* IO semaphore */

        /* for checkpoint */
        struct f2fs_checkpoint *ckpt;           /* raw checkpoint pointer */
        struct inode *meta_inode;               /* cache meta blocks */
        struct mutex cp_mutex;                  /* checkpoint procedure lock */
        struct rw_semaphore cp_rwsem;           /* blocking FS operations */
        struct mutex node_write;                /* locking node writes */
        struct mutex writepages;                /* mutex for writepages() */
        bool por_doing;                         /* recovery is doing or not */
        bool on_build_free_nids;                /* build_free_nids is doing */
        wait_queue_head_t cp_wait;

        /* for orphan inode management */
        struct list_head orphan_inode_list;     /* orphan inode list */
        struct mutex orphan_inode_mutex;        /* for orphan inode list */
        unsigned int n_orphans;                 /* # of orphan inodes */

        /* for directory inode management */
        struct list_head dir_inode_list;        /* dir inode list */
        spinlock_t dir_inode_lock;              /* for dir inode list lock */

        /* basic file system units */
        unsigned int log_sectors_per_block;     /* log2 sectors per block */
        unsigned int log_blocksize;             /* log2 block size */
        unsigned int blocksize;                 /* block size */
        unsigned int root_ino_num;              /* root inode number*/
        unsigned int node_ino_num;              /* node inode number*/
        unsigned int meta_ino_num;              /* meta inode number*/
        unsigned int log_blocks_per_seg;        /* log2 blocks per segment */
        unsigned int blocks_per_seg;            /* blocks per segment */
        unsigned int segs_per_sec;              /* segments per section */
        unsigned int secs_per_zone;             /* sections per zone */
        unsigned int total_sections;            /* total section count */
        unsigned int total_node_count;          /* total node block count */
        unsigned int total_valid_node_count;    /* valid node block count */
        unsigned int total_valid_inode_count;   /* valid inode count */
        int active_logs;                        /* # of active logs */

        block_t user_block_count;               /* # of user blocks */
        block_t total_valid_block_count;        /* # of valid blocks */
        block_t alloc_valid_block_count;        /* # of allocated blocks */
        block_t last_valid_block_count;         /* for recovery */
        u32 s_next_generation;                  /* for NFS support */
        atomic_t nr_pages[NR_COUNT_TYPE];       /* # of pages, see count_type */

        struct f2fs_mount_info mount_opt;       /* mount options */

        /* for cleaning operations */
        struct mutex gc_mutex;                  /* mutex for GC */
        struct f2fs_gc_kthread  *gc_thread;     /* GC thread */
        unsigned int cur_victim_sec;            /* current victim section num */

        /*
         * for stat information.
         * one is for the LFS mode, and the other is for the SSR mode.
         */
#ifdef CONFIG_F2FS_STAT_FS
        struct f2fs_stat_info *stat_info;       /* FS status information */
        unsigned int segment_count[2];          /* # of allocated segments */
        unsigned int block_count[2];            /* # of allocated blocks */
        int total_hit_ext, read_hit_ext;        /* extent cache hit ratio */
        int bg_gc;                              /* background gc calls */
        unsigned int n_dirty_dirs;              /* # of dir inodes */
#endif
        unsigned int last_victim[2];            /* last victim segment # */
        spinlock_t stat_lock;                   /* lock for stat operations */

        /* For sysfs suppport */
        struct kobject s_kobj;
        struct completion s_kobj_unregister;
};

/*
 * Inline functions
 */
static inline struct f2fs_inode_info *F2FS_I(struct inode *inode)
{
        return container_of(inode, struct f2fs_inode_info, vfs_inode);
}

static inline struct f2fs_sb_info *F2FS_SB(struct super_block *sb)
{
        return sb->s_fs_info;
}

static inline struct f2fs_super_block *F2FS_RAW_SUPER(struct f2fs_sb_info *sbi)
{
        return (struct f2fs_super_block *)(sbi->raw_super);
}

static inline struct f2fs_checkpoint *F2FS_CKPT(struct f2fs_sb_info *sbi)
{
        return (struct f2fs_checkpoint *)(sbi->ckpt);
}

static inline struct f2fs_node *F2FS_NODE(struct page *page)
{
        return (struct f2fs_node *)page_address(page);
}

static inline struct f2fs_nm_info *NM_I(struct f2fs_sb_info *sbi)
{
        return (struct f2fs_nm_info *)(sbi->nm_info);
}

static inline struct f2fs_sm_info *SM_I(struct f2fs_sb_info *sbi)
{
        return (struct f2fs_sm_info *)(sbi->sm_info);
}

static inline struct sit_info *SIT_I(struct f2fs_sb_info *sbi)
{
        return (struct sit_info *)(SM_I(sbi)->sit_info);
}

static inline struct free_segmap_info *FREE_I(struct f2fs_sb_info *sbi)
{
        return (struct free_segmap_info *)(SM_I(sbi)->free_info);
}

static inline struct dirty_seglist_info *DIRTY_I(struct f2fs_sb_info *sbi)
{
        return (struct dirty_seglist_info *)(SM_I(sbi)->dirty_info);
}

static inline void F2FS_SET_SB_DIRT(struct f2fs_sb_info *sbi)
{
        sbi->s_dirty = 1;
}

static inline void F2FS_RESET_SB_DIRT(struct f2fs_sb_info *sbi)
{
        sbi->s_dirty = 0;
}

static inline unsigned long long cur_cp_version(struct f2fs_checkpoint *cp)
{
        return le64_to_cpu(cp->checkpoint_ver);
}

static inline bool is_set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
{
        unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
        return ckpt_flags & f;
}

static inline void set_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
{
        unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
        ckpt_flags |= f;
        cp->ckpt_flags = cpu_to_le32(ckpt_flags);
}

static inline void clear_ckpt_flags(struct f2fs_checkpoint *cp, unsigned int f)
{
        unsigned int ckpt_flags = le32_to_cpu(cp->ckpt_flags);
        ckpt_flags &= (~f);
        cp->ckpt_flags = cpu_to_le32(ckpt_flags);
}

static inline void f2fs_lock_op(struct f2fs_sb_info *sbi)
{
        down_read(&sbi->cp_rwsem);
}

static inline void f2fs_unlock_op(struct f2fs_sb_info *sbi)
{
        up_read(&sbi->cp_rwsem);
}

static inline void f2fs_lock_all(struct f2fs_sb_info *sbi)
{
        down_write_nest_lock(&sbi->cp_rwsem, &sbi->cp_mutex);
}

static inline void f2fs_unlock_all(struct f2fs_sb_info *sbi)
{
        up_write(&sbi->cp_rwsem);
}

/*
 * Check whether the given nid is within node id range.
 */
static inline int check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
{
        WARN_ON((nid >= NM_I(sbi)->max_nid));
        if (nid >= NM_I(sbi)->max_nid)
                return -EINVAL;
        return 0;
}

#define F2FS_DEFAULT_ALLOCATED_BLOCKS   1

/*
 * Check whether the inode has blocks or not
 */
static inline int F2FS_HAS_BLOCKS(struct inode *inode)
{
        if (F2FS_I(inode)->i_xattr_nid)
                return (inode->i_blocks > F2FS_DEFAULT_ALLOCATED_BLOCKS + 1);
        else
                return (inode->i_blocks > F2FS_DEFAULT_ALLOCATED_BLOCKS);
}

static inline bool inc_valid_block_count(struct f2fs_sb_info *sbi,
                                 struct inode *inode, blkcnt_t count)
{
        block_t valid_block_count;

        spin_lock(&sbi->stat_lock);
        valid_block_count =
                sbi->total_valid_block_count + (block_t)count;
        if (valid_block_count > sbi->user_block_count) {
                spin_unlock(&sbi->stat_lock);
                return false;
        }
        inode->i_blocks += count;
        sbi->total_valid_block_count = valid_block_count;
        sbi->alloc_valid_block_count += (block_t)count;
        spin_unlock(&sbi->stat_lock);
        return true;
}

static inline int dec_valid_block_count(struct f2fs_sb_info *sbi,
                                                struct inode *inode,
                                                blkcnt_t count)
{
        spin_lock(&sbi->stat_lock);
        f2fs_bug_on(sbi->total_valid_block_count < (block_t) count);
        f2fs_bug_on(inode->i_blocks < count);
        inode->i_blocks -= count;
        sbi->total_valid_block_count -= (block_t)count;
        spin_unlock(&sbi->stat_lock);
        return 0;
}

static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type)
{
        atomic_inc(&sbi->nr_pages[count_type]);
        F2FS_SET_SB_DIRT(sbi);
}

static inline void inode_inc_dirty_dents(struct inode *inode)
{
        atomic_inc(&F2FS_I(inode)->dirty_dents);
}

static inline void dec_page_count(struct f2fs_sb_info *sbi, int count_type)
{
        atomic_dec(&sbi->nr_pages[count_type]);
}

static inline void inode_dec_dirty_dents(struct inode *inode)
{
        atomic_dec(&F2FS_I(inode)->dirty_dents);
}

static inline int get_pages(struct f2fs_sb_info *sbi, int count_type)
{
        return atomic_read(&sbi->nr_pages[count_type]);
}

static inline int get_blocktype_secs(struct f2fs_sb_info *sbi, int block_type)
{
        unsigned int pages_per_sec = sbi->segs_per_sec *
                                        (1 << sbi->log_blocks_per_seg);
        return ((get_pages(sbi, block_type) + pages_per_sec - 1)
                        >> sbi->log_blocks_per_seg) / sbi->segs_per_sec;
}

static inline block_t valid_user_blocks(struct f2fs_sb_info *sbi)
{
        block_t ret;
        spin_lock(&sbi->stat_lock);
        ret = sbi->total_valid_block_count;
        spin_unlock(&sbi->stat_lock);
        return ret;
}

static inline unsigned long __bitmap_size(struct f2fs_sb_info *sbi, int flag)
{
        struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);

        /* return NAT or SIT bitmap */
        if (flag == NAT_BITMAP)
                return le32_to_cpu(ckpt->nat_ver_bitmap_bytesize);
        else if (flag == SIT_BITMAP)
                return le32_to_cpu(ckpt->sit_ver_bitmap_bytesize);

        return 0;
}

static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag)
{
        struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
        int offset = (flag == NAT_BITMAP) ?
                        le32_to_cpu(ckpt->sit_ver_bitmap_bytesize) : 0;
        return &ckpt->sit_nat_version_bitmap + offset;
}

static inline block_t __start_cp_addr(struct f2fs_sb_info *sbi)
{
        block_t start_addr;
        struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
        unsigned long long ckpt_version = cur_cp_version(ckpt);

        start_addr = le32_to_cpu(F2FS_RAW_SUPER(sbi)->cp_blkaddr);

        /*
         * odd numbered checkpoint should at cp segment 0
         * and even segent must be at cp segment 1
         */
        if (!(ckpt_version & 1))
                start_addr += sbi->blocks_per_seg;

        return start_addr;
}

static inline block_t __start_sum_addr(struct f2fs_sb_info *sbi)
{
        return le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_start_sum);
}

static inline bool inc_valid_node_count(struct f2fs_sb_info *sbi,
                                                struct inode *inode,
                                                unsigned int count)
{
        block_t valid_block_count;
        unsigned int valid_node_count;

        spin_lock(&sbi->stat_lock);

        valid_block_count = sbi->total_valid_block_count + (block_t)count;
        sbi->alloc_valid_block_count += (block_t)count;
        valid_node_count = sbi->total_valid_node_count + count;

        if (valid_block_count > sbi->user_block_count) {
                spin_unlock(&sbi->stat_lock);
                return false;
        }

        if (valid_node_count > sbi->total_node_count) {
                spin_unlock(&sbi->stat_lock);
                return false;
        }

        if (inode)
                inode->i_blocks += count;
        sbi->total_valid_node_count = valid_node_count;
        sbi->total_valid_block_count = valid_block_count;
        spin_unlock(&sbi->stat_lock);

        return true;
}

static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
                                                struct inode *inode,
                                                unsigned int count)
{
        spin_lock(&sbi->stat_lock);

        f2fs_bug_on(sbi->total_valid_block_count < count);
        f2fs_bug_on(sbi->total_valid_node_count < count);
        f2fs_bug_on(inode->i_blocks < count);

        inode->i_blocks -= count;
        sbi->total_valid_node_count -= count;
        sbi->total_valid_block_count -= (block_t)count;

        spin_unlock(&sbi->stat_lock);
}

static inline unsigned int valid_node_count(struct f2fs_sb_info *sbi)
{
        unsigned int ret;
        spin_lock(&sbi->stat_lock);
        ret = sbi->total_valid_node_count;
        spin_unlock(&sbi->stat_lock);
        return ret;
}

static inline void inc_valid_inode_count(struct f2fs_sb_info *sbi)
{
        spin_lock(&sbi->stat_lock);
        f2fs_bug_on(sbi->total_valid_inode_count == sbi->total_node_count);
        sbi->total_valid_inode_count++;
        spin_unlock(&sbi->stat_lock);
}

static inline int dec_valid_inode_count(struct f2fs_sb_info *sbi)
{
        spin_lock(&sbi->stat_lock);
        f2fs_bug_on(!sbi->total_valid_inode_count);
        sbi->total_valid_inode_count--;
        spin_unlock(&sbi->stat_lock);
        return 0;
}

static inline unsigned int valid_inode_count(struct f2fs_sb_info *sbi)
{
        unsigned int ret;
        spin_lock(&sbi->stat_lock);
        ret = sbi->total_valid_inode_count;
        spin_unlock(&sbi->stat_lock);
        return ret;
}

static inline void f2fs_put_page(struct page *page, int unlock)
{
        if (!page || IS_ERR(page))
                return;

        if (unlock) {
                f2fs_bug_on(!PageLocked(page));
                unlock_page(page);
        }
        page_cache_release(page);
}

static inline void f2fs_put_dnode(struct dnode_of_data *dn)
{
        if (dn->node_page)
                f2fs_put_page(dn->node_page, 1);
        if (dn->inode_page && dn->node_page != dn->inode_page)
                f2fs_put_page(dn->inode_page, 0);
        dn->node_page = NULL;
        dn->inode_page = NULL;
}

static inline struct kmem_cache *f2fs_kmem_cache_create(const char *name,
                                        size_t size, void (*ctor)(void *))
{
        return kmem_cache_create(name, size, 0, SLAB_RECLAIM_ACCOUNT, ctor);
}

static inline void *f2fs_kmem_cache_alloc(struct kmem_cache *cachep,
                                                gfp_t flags)
{
        void *entry;
retry:
        entry = kmem_cache_alloc(cachep, flags);
        if (!entry) {
                cond_resched();
                goto retry;
        }

        return entry;
}

#define RAW_IS_INODE(p) ((p)->footer.nid == (p)->footer.ino)

static inline bool IS_INODE(struct page *page)
{
        struct f2fs_node *p = F2FS_NODE(page);
        return RAW_IS_INODE(p);
}

static inline __le32 *blkaddr_in_node(struct f2fs_node *node)
{
        return RAW_IS_INODE(node) ? node->i.i_addr : node->dn.addr;
}

static inline block_t datablock_addr(struct page *node_page,
                unsigned int offset)
{
        struct f2fs_node *raw_node;
        __le32 *addr_array;
        raw_node = F2FS_NODE(node_page);
        addr_array = blkaddr_in_node(raw_node);
        return le32_to_cpu(addr_array[offset]);
}

static inline int f2fs_test_bit(unsigned int nr, char *addr)
{
        int mask;

        addr += (nr >> 3);
        mask = 1 << (7 - (nr & 0x07));
        return mask & *addr;
}

static inline int f2fs_set_bit(unsigned int nr, char *addr)
{
        int mask;
        int ret;

        addr += (nr >> 3);
        mask = 1 << (7 - (nr & 0x07));
        ret = mask & *addr;
        *addr |= mask;
        return ret;
}

static inline int f2fs_clear_bit(unsigned int nr, char *addr)
{
        int mask;
        int ret;

        addr += (nr >> 3);
        mask = 1 << (7 - (nr & 0x07));
        ret = mask & *addr;
        *addr &= ~mask;
        return ret;
}

/* used for f2fs_inode_info->flags */
enum {
        FI_NEW_INODE,           /* indicate newly allocated inode */
        FI_DIRTY_INODE,         /* indicate inode is dirty or not */
        FI_INC_LINK,            /* need to increment i_nlink */
        FI_ACL_MODE,            /* indicate acl mode */
        FI_NO_ALLOC,            /* should not allocate any blocks */
        FI_UPDATE_DIR,          /* should update inode block for consistency */
        FI_DELAY_IPUT,          /* used for the recovery */
        FI_INLINE_XATTR,        /* used for inline xattr */
};

static inline void set_inode_flag(struct f2fs_inode_info *fi, int flag)
{
        set_bit(flag, &fi->flags);
}

static inline int is_inode_flag_set(struct f2fs_inode_info *fi, int flag)
{
        return test_bit(flag, &fi->flags);
}

static inline void clear_inode_flag(struct f2fs_inode_info *fi, int flag)
{
        clear_bit(flag, &fi->flags);
}

static inline void set_acl_inode(struct f2fs_inode_info *fi, umode_t mode)
{
        fi->i_acl_mode = mode;
        set_inode_flag(fi, FI_ACL_MODE);
}

static inline int cond_clear_inode_flag(struct f2fs_inode_info *fi, int flag)
{
        if (is_inode_flag_set(fi, FI_ACL_MODE)) {
                clear_inode_flag(fi, FI_ACL_MODE);
                return 1;
        }
        return 0;
}

static inline void get_inline_info(struct f2fs_inode_info *fi,
                                        struct f2fs_inode *ri)
{
        if (ri->i_inline & F2FS_INLINE_XATTR)
                set_inode_flag(fi, FI_INLINE_XATTR);
}

static inline void set_raw_inline(struct f2fs_inode_info *fi,
                                        struct f2fs_inode *ri)
{
        ri->i_inline = 0;

        if (is_inode_flag_set(fi, FI_INLINE_XATTR))
                ri->i_inline |= F2FS_INLINE_XATTR;
}

static inline unsigned int addrs_per_inode(struct f2fs_inode_info *fi)
{
        if (is_inode_flag_set(fi, FI_INLINE_XATTR))
                return DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS;
        return DEF_ADDRS_PER_INODE;
}

static inline void *inline_xattr_addr(struct page *page)
{
        struct f2fs_inode *ri;
        ri = (struct f2fs_inode *)page_address(page);
        return (void *)&(ri->i_addr[DEF_ADDRS_PER_INODE -
                                        F2FS_INLINE_XATTR_ADDRS]);
}

static inline int inline_xattr_size(struct inode *inode)
{
        if (is_inode_flag_set(F2FS_I(inode), FI_INLINE_XATTR))
                return F2FS_INLINE_XATTR_ADDRS << 2;
        else
                return 0;
}

static inline int f2fs_readonly(struct super_block *sb)
{
        return sb->s_flags & MS_RDONLY;
}

/*
 * file.c
 */
int f2fs_sync_file(struct file *, loff_t, loff_t, int);
void truncate_data_blocks(struct dnode_of_data *);
void f2fs_truncate(struct inode *);
int f2fs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
int f2fs_setattr(struct dentry *, struct iattr *);
int truncate_hole(struct inode *, pgoff_t, pgoff_t);
int truncate_data_blocks_range(struct dnode_of_data *, int);
long f2fs_ioctl(struct file *, unsigned int, unsigned long);
long f2fs_compat_ioctl(struct file *, unsigned int, unsigned long);

/*
 * inode.c
 */
void f2fs_set_inode_flags(struct inode *);
struct inode *f2fs_iget(struct super_block *, unsigned long);
int try_to_free_nats(struct f2fs_sb_info *, int);
void update_inode(struct inode *, struct page *);
int update_inode_page(struct inode *);
int f2fs_write_inode(struct inode *, struct writeback_control *);
void f2fs_evict_inode(struct inode *);

/*
 * namei.c
 */
struct dentry *f2fs_get_parent(struct dentry *child);

/*
 * dir.c
 */
struct f2fs_dir_entry *f2fs_find_entry(struct inode *, struct qstr *,
                                                        struct page **);
struct f2fs_dir_entry *f2fs_parent_dir(struct inode *, struct page **);
ino_t f2fs_inode_by_name(struct inode *, struct qstr *);
void f2fs_set_link(struct inode *, struct f2fs_dir_entry *,
                                struct page *, struct inode *);
int update_dent_inode(struct inode *, const struct qstr *);
int __f2fs_add_link(struct inode *, const struct qstr *, struct inode *);
void f2fs_delete_entry(struct f2fs_dir_entry *, struct page *, struct inode *);
int f2fs_make_empty(struct inode *, struct inode *);
bool f2fs_empty_dir(struct inode *);

static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)
{
        return __f2fs_add_link(dentry->d_parent->d_inode, &dentry->d_name,
                                inode);
}

/*
 * super.c
 */
int f2fs_sync_fs(struct super_block *, int);
extern __printf(3, 4)
void f2fs_msg(struct super_block *, const char *, const char *, ...);

/*
 * hash.c
 */
f2fs_hash_t f2fs_dentry_hash(const char *, size_t);

/*
 * node.c
 */
struct dnode_of_data;
struct node_info;

int is_checkpointed_node(struct f2fs_sb_info *, nid_t);
void get_node_info(struct f2fs_sb_info *, nid_t, struct node_info *);
int get_dnode_of_data(struct dnode_of_data *, pgoff_t, int);
int truncate_inode_blocks(struct inode *, pgoff_t);
int truncate_xattr_node(struct inode *, struct page *);
int wait_on_node_pages_writeback(struct f2fs_sb_info *, nid_t);
int remove_inode_page(struct inode *);
struct page *new_inode_page(struct inode *, const struct qstr *);
struct page *new_node_page(struct dnode_of_data *, unsigned int, struct page *);
void ra_node_page(struct f2fs_sb_info *, nid_t);
struct page *get_node_page(struct f2fs_sb_info *, pgoff_t);
struct page *get_node_page_ra(struct page *, int);
void sync_inode_page(struct dnode_of_data *);
int sync_node_pages(struct f2fs_sb_info *, nid_t, struct writeback_control *);
bool alloc_nid(struct f2fs_sb_info *, nid_t *);
void alloc_nid_done(struct f2fs_sb_info *, nid_t);
void alloc_nid_failed(struct f2fs_sb_info *, nid_t);
void recover_node_page(struct f2fs_sb_info *, struct page *,
                struct f2fs_summary *, struct node_info *, block_t);
int recover_inode_page(struct f2fs_sb_info *, struct page *);
int restore_node_summary(struct f2fs_sb_info *, unsigned int,
                                struct f2fs_summary_block *);
void flush_nat_entries(struct f2fs_sb_info *);
int build_node_manager(struct f2fs_sb_info *);
void destroy_node_manager(struct f2fs_sb_info *);
int __init create_node_manager_caches(void);
void destroy_node_manager_caches(void);

/*
 * segment.c
 */
void f2fs_balance_fs(struct f2fs_sb_info *);
void f2fs_balance_fs_bg(struct f2fs_sb_info *);
void invalidate_blocks(struct f2fs_sb_info *, block_t);
void clear_prefree_segments(struct f2fs_sb_info *);
int npages_for_summary_flush(struct f2fs_sb_info *);
void allocate_new_segments(struct f2fs_sb_info *);
struct page *get_sum_page(struct f2fs_sb_info *, unsigned int);
struct bio *f2fs_bio_alloc(struct block_device *, int);
void f2fs_submit_bio(struct f2fs_sb_info *, enum page_type, bool);
void f2fs_wait_on_page_writeback(struct page *, enum page_type, bool);
void write_meta_page(struct f2fs_sb_info *, struct page *);
void write_node_page(struct f2fs_sb_info *, struct page *, unsigned int,
                                        block_t, block_t *);
void write_data_page(struct inode *, struct page *, struct dnode_of_data*,
                                        block_t, block_t *);
void rewrite_data_page(struct f2fs_sb_info *, struct page *, block_t);
void recover_data_page(struct f2fs_sb_info *, struct page *,
                                struct f2fs_summary *, block_t, block_t);
void rewrite_node_page(struct f2fs_sb_info *, struct page *,
                                struct f2fs_summary *, block_t, block_t);
void write_data_summaries(struct f2fs_sb_info *, block_t);
void write_node_summaries(struct f2fs_sb_info *, block_t);
int lookup_journal_in_cursum(struct f2fs_summary_block *,
                                        int, unsigned int, int);
void flush_sit_entries(struct f2fs_sb_info *);
int build_segment_manager(struct f2fs_sb_info *);
void destroy_segment_manager(struct f2fs_sb_info *);
int __init create_segment_manager_caches(void);
void destroy_segment_manager_caches(void);

/*
 * checkpoint.c
 */
struct page *grab_meta_page(struct f2fs_sb_info *, pgoff_t);
struct page *get_meta_page(struct f2fs_sb_info *, pgoff_t);
long sync_meta_pages(struct f2fs_sb_info *, enum page_type, long);
int acquire_orphan_inode(struct f2fs_sb_info *);
void release_orphan_inode(struct f2fs_sb_info *);
void add_orphan_inode(struct f2fs_sb_info *, nid_t);
void remove_orphan_inode(struct f2fs_sb_info *, nid_t);
int recover_orphan_inodes(struct f2fs_sb_info *);
int get_valid_checkpoint(struct f2fs_sb_info *);
void set_dirty_dir_page(struct inode *, struct page *);
void add_dirty_dir_inode(struct inode *);
void remove_dirty_dir_inode(struct inode *);
struct inode *check_dirty_dir_inode(struct f2fs_sb_info *, nid_t);
void sync_dirty_dir_inodes(struct f2fs_sb_info *);
void write_checkpoint(struct f2fs_sb_info *, bool);
void init_orphan_info(struct f2fs_sb_info *);
int __init create_checkpoint_caches(void);
void destroy_checkpoint_caches(void);

/*
 * data.c
 */
int reserve_new_block(struct dnode_of_data *);
void update_extent_cache(block_t, struct dnode_of_data *);
struct page *find_data_page(struct inode *, pgoff_t, bool);
struct page *get_lock_data_page(struct inode *, pgoff_t);
struct page *get_new_data_page(struct inode *, struct page *, pgoff_t, bool);
int f2fs_readpage(struct f2fs_sb_info *, struct page *, block_t, int);
int do_write_data_page(struct page *);

/*
 * gc.c
 */
int start_gc_thread(struct f2fs_sb_info *);
void stop_gc_thread(struct f2fs_sb_info *);
block_t start_bidx_of_node(unsigned int, struct f2fs_inode_info *);
int f2fs_gc(struct f2fs_sb_info *);
void build_gc_manager(struct f2fs_sb_info *);
int __init create_gc_caches(void);
void destroy_gc_caches(void);

/*
 * recovery.c
 */
int recover_fsync_data(struct f2fs_sb_info *);
bool space_for_roll_forward(struct f2fs_sb_info *);

/*
 * debug.c
 */
#ifdef CONFIG_F2FS_STAT_FS
struct f2fs_stat_info {
        struct list_head stat_list;
        struct f2fs_sb_info *sbi;
        struct mutex stat_lock;
        int all_area_segs, sit_area_segs, nat_area_segs, ssa_area_segs;
        int main_area_segs, main_area_sections, main_area_zones;
        int hit_ext, total_ext;
        int ndirty_node, ndirty_dent, ndirty_dirs, ndirty_meta;
        int nats, sits, fnids;
        int total_count, utilization;
        int bg_gc;
        unsigned int valid_count, valid_node_count, valid_inode_count;
        unsigned int bimodal, avg_vblocks;
        int util_free, util_valid, util_invalid;
        int rsvd_segs, overp_segs;
        int dirty_count, node_pages, meta_pages;
        int prefree_count, call_count;
        int tot_segs, node_segs, data_segs, free_segs, free_secs;
        int tot_blks, data_blks, node_blks;
        int curseg[NR_CURSEG_TYPE];
        int cursec[NR_CURSEG_TYPE];
        int curzone[NR_CURSEG_TYPE];

        unsigned int segment_count[2];
        unsigned int block_count[2];
        unsigned base_mem, cache_mem;
};

static inline struct f2fs_stat_info *F2FS_STAT(struct f2fs_sb_info *sbi)
{
        return (struct f2fs_stat_info*)sbi->stat_info;
}

#define stat_inc_call_count(si)         ((si)->call_count++)
#define stat_inc_bggc_count(sbi)        ((sbi)->bg_gc++)
#define stat_inc_dirty_dir(sbi)         ((sbi)->n_dirty_dirs++)
#define stat_dec_dirty_dir(sbi)         ((sbi)->n_dirty_dirs--)
#define stat_inc_total_hit(sb)          ((F2FS_SB(sb))->total_hit_ext++)
#define stat_inc_read_hit(sb)           ((F2FS_SB(sb))->read_hit_ext++)
#define stat_inc_seg_type(sbi, curseg)                                  \
                ((sbi)->segment_count[(curseg)->alloc_type]++)
#define stat_inc_block_count(sbi, curseg)                               \
                ((sbi)->block_count[(curseg)->alloc_type]++)

#define stat_inc_seg_count(sbi, type)                                   \
        do {                                                            \
                struct f2fs_stat_info *si = F2FS_STAT(sbi);             \
                (si)->tot_segs++;                                       \
                if (type == SUM_TYPE_DATA)                              \
                        si->data_segs++;                                \
                else                                                    \
                        si->node_segs++;                                \
        } while (0)

#define stat_inc_tot_blk_count(si, blks)                                \
        (si->tot_blks += (blks))

#define stat_inc_data_blk_count(sbi, blks)                              \
        do {                                                            \
                struct f2fs_stat_info *si = F2FS_STAT(sbi);             \
                stat_inc_tot_blk_count(si, blks);                       \
                si->data_blks += (blks);                                \
        } while (0)

#define stat_inc_node_blk_count(sbi, blks)                              \
        do {                                                            \
                struct f2fs_stat_info *si = F2FS_STAT(sbi);             \
                stat_inc_tot_blk_count(si, blks);                       \
                si->node_blks += (blks);                                \
        } while (0)

int f2fs_build_stats(struct f2fs_sb_info *);
void f2fs_destroy_stats(struct f2fs_sb_info *);
void __init f2fs_create_root_stats(void);
void f2fs_destroy_root_stats(void);
#else
#define stat_inc_call_count(si)
#define stat_inc_bggc_count(si)
#define stat_inc_dirty_dir(sbi)
#define stat_dec_dirty_dir(sbi)
#define stat_inc_total_hit(sb)
#define stat_inc_read_hit(sb)
#define stat_inc_seg_type(sbi, curseg)
#define stat_inc_block_count(sbi, curseg)
#define stat_inc_seg_count(si, type)
#define stat_inc_tot_blk_count(si, blks)
#define stat_inc_data_blk_count(si, blks)
#define stat_inc_node_blk_count(sbi, blks)

static inline int f2fs_build_stats(struct f2fs_sb_info *sbi) { return 0; }
static inline void f2fs_destroy_stats(struct f2fs_sb_info *sbi) { }
static inline void __init f2fs_create_root_stats(void) { }
static inline void f2fs_destroy_root_stats(void) { }
#endif

extern const struct file_operations f2fs_dir_operations;
extern const struct file_operations f2fs_file_operations;
extern const struct inode_operations f2fs_file_inode_operations;
extern const struct address_space_operations f2fs_dblock_aops;
extern const struct address_space_operations f2fs_node_aops;
extern const struct address_space_operations f2fs_meta_aops;
extern const struct inode_operations f2fs_dir_inode_operations;
extern const struct inode_operations f2fs_symlink_inode_operations;
extern const struct inode_operations f2fs_special_inode_operations;
#endif