/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef __BTRFS_I__
#define __BTRFS_I__

#include <linux/hash.h>
#include "extent_map.h"
#include "extent_io.h"
#include "ordered-data.h"
#include "delayed-inode.h"

/*
 * ordered_data_close is set by truncate when a file that used
 * to have good data has been truncated to zero.  When it is set
 * the btrfs file release call will add this inode to the
 * ordered operations list so that we make sure to flush out any
 * new data the application may have written before commit.
 */
#define BTRFS_INODE_ORDERED_DATA_CLOSE          0
#define BTRFS_INODE_ORPHAN_META_RESERVED        1
#define BTRFS_INODE_DUMMY                       2
#define BTRFS_INODE_IN_DEFRAG                   3
#define BTRFS_INODE_DELALLOC_META_RESERVED      4
#define BTRFS_INODE_HAS_ORPHAN_ITEM             5
#define BTRFS_INODE_HAS_ASYNC_EXTENT            6
#define BTRFS_INODE_NEEDS_FULL_SYNC             7
#define BTRFS_INODE_COPY_EVERYTHING             8
#define BTRFS_INODE_IN_DELALLOC_LIST            9
#define BTRFS_INODE_READDIO_NEED_LOCK           10
#define BTRFS_INODE_HAS_PROPS                   11

/* in memory btrfs inode */
struct btrfs_inode {
        /* which subvolume this inode belongs to */
        struct btrfs_root *root;

        /* key used to find this inode on disk.  This is used by the code
         * to read in roots of subvolumes
         */
        struct btrfs_key location;

        /*
         * Lock for counters and all fields used to determine if the inode is in
         * the log or not (last_trans, last_sub_trans, last_log_commit,
         * logged_trans).
         */
        spinlock_t lock;

        /* the extent_tree has caches of all the extent mappings to disk */
        struct extent_map_tree extent_tree;

        /* the io_tree does range state (DIRTY, LOCKED etc) */
        struct extent_io_tree io_tree;

        /* special utility tree used to record which mirrors have already been
         * tried when checksums fail for a given block
         */
        struct extent_io_tree io_failure_tree;

        /* held while logging the inode in tree-log.c */
        struct mutex log_mutex;

        /* held while doing delalloc reservations */
        struct mutex delalloc_mutex;

        /* used to order data wrt metadata */
        struct btrfs_ordered_inode_tree ordered_tree;

        /* list of all the delalloc inodes in the FS.  There are times we need
         * to write all the delalloc pages to disk, and this list is used
         * to walk them all.
         */
        struct list_head delalloc_inodes;

        /* node for the red-black tree that links inodes in subvolume root */
        struct rb_node rb_node;

        unsigned long runtime_flags;

        /* Keep track of who's O_SYNC/fsyncing currently */
        atomic_t sync_writers;

        /* full 64 bit generation number, struct vfs_inode doesn't have a big
         * enough field for this.
         */
        u64 generation;

        /*
         * transid of the trans_handle that last modified this inode
         */
        u64 last_trans;

        /*
         * transid that last logged this inode
         */
        u64 logged_trans;

        /*
         * log transid when this inode was last modified
         */
        int last_sub_trans;

        /* a local copy of root's last_log_commit */
        int last_log_commit;

        /* total number of bytes pending delalloc, used by stat to calc the
         * real block usage of the file
         */
        u64 delalloc_bytes;

        /*
         * total number of bytes pending defrag, used by stat to check whether
         * it needs COW.
         */
        u64 defrag_bytes;

        /*
         * the size of the file stored in the metadata on disk.  data=ordered
         * means the in-memory i_size might be larger than the size on disk
         * because not all the blocks are written yet.
         */
        u64 disk_i_size;

        /*
         * if this is a directory then index_cnt is the counter for the index
         * number for new files that are created
         */
        u64 index_cnt;

        /* Cache the directory index number to speed the dir/file remove */
        u64 dir_index;

        /* the fsync log has some corner cases that mean we have to check
         * directories to see if any unlinks have been done before
         * the directory was logged.  See tree-log.c for all the
         * details
         */
        u64 last_unlink_trans;

        /*
         * Number of bytes outstanding that are going to need csums.  This is
         * used in ENOSPC accounting.
         */
        u64 csum_bytes;

        /* flags field from the on disk inode */
        u32 flags;

        /*
         * Counters to keep track of the number of extent item's we may use due
         * to delalloc and such.  outstanding_extents is the number of extent
         * items we think we'll end up using, and reserved_extents is the number
         * of extent items we've reserved metadata for.
         */
        unsigned outstanding_extents;
        unsigned reserved_extents;

        /*
         * always compress this one file
         */
        unsigned force_compress;

        struct btrfs_delayed_node *delayed_node;

        /* File creation time. */
        struct timespec i_otime;

        /* Hook into fs_info->delayed_iputs */
        struct list_head delayed_iput;
        long delayed_iput_count;

        /*
         * To avoid races between lockless (i_mutex not held) direct IO writes
         * and concurrent fsync requests. Direct IO writes must acquire read
         * access on this semaphore for creating an extent map and its
         * corresponding ordered extent. The fast fsync path must acquire write
         * access on this semaphore before it collects ordered extents and
         * extent maps.
         */
        struct rw_semaphore dio_sem;

        struct inode vfs_inode;
};

extern unsigned char btrfs_filetype_table[];

static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
{
        return container_of(inode, struct btrfs_inode, vfs_inode);
}

static inline unsigned long btrfs_inode_hash(u64 objectid,
                                             const struct btrfs_root *root)
{
        u64 h = objectid ^ (root->objectid * GOLDEN_RATIO_PRIME);

#if BITS_PER_LONG == 32
        h = (h >> 32) ^ (h & 0xffffffff);
#endif

        return (unsigned long)h;
}

static inline void btrfs_insert_inode_hash(struct inode *inode)
{
        unsigned long h = btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root);

        __insert_inode_hash(inode, h);
}

static inline u64 btrfs_ino(struct inode *inode)
{
        u64 ino = BTRFS_I(inode)->location.objectid;

        /*
         * !ino: btree_inode
         * type == BTRFS_ROOT_ITEM_KEY: subvol dir
         */
        if (!ino || BTRFS_I(inode)->location.type == BTRFS_ROOT_ITEM_KEY)
                ino = inode->i_ino;
        return ino;
}

static inline void btrfs_i_size_write(struct inode *inode, u64 size)
{
        i_size_write(inode, size);
        BTRFS_I(inode)->disk_i_size = size;
}

static inline bool btrfs_is_free_space_inode(struct inode *inode)
{
        struct btrfs_root *root = BTRFS_I(inode)->root;

        if (root == root->fs_info->tree_root &&
            btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)
                return true;
        if (BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID)
                return true;
        return false;
}

static inline int btrfs_inode_in_log(struct inode *inode, u64 generation)
{
        int ret = 0;

        spin_lock(&BTRFS_I(inode)->lock);
        if (BTRFS_I(inode)->logged_trans == generation &&
            BTRFS_I(inode)->last_sub_trans <=
            BTRFS_I(inode)->last_log_commit &&
            BTRFS_I(inode)->last_sub_trans <=
            BTRFS_I(inode)->root->last_log_commit) {
                /*
                 * After a ranged fsync we might have left some extent maps
                 * (that fall outside the fsync's range). So return false
                 * here if the list isn't empty, to make sure btrfs_log_inode()
                 * will be called and process those extent maps.
                 */
                smp_mb();
                if (list_empty(&BTRFS_I(inode)->extent_tree.modified_extents))
                        ret = 1;
        }
        spin_unlock(&BTRFS_I(inode)->lock);
        return ret;
}

#define BTRFS_DIO_ORIG_BIO_SUBMITTED    0x1

struct btrfs_dio_private {
        struct inode *inode;
        unsigned long flags;
        u64 logical_offset;
        u64 disk_bytenr;
        u64 bytes;
        void *private;

        /* number of bios pending for this dio */
        atomic_t pending_bios;

        /* IO errors */
        int errors;

        /* orig_bio is our btrfs_io_bio */
        struct bio *orig_bio;

        /* dio_bio came from fs/direct-io.c */
        struct bio *dio_bio;

        /*
         * The original bio may be split to several sub-bios, this is
         * done during endio of sub-bios
         */
        int (*subio_endio)(struct inode *, struct btrfs_io_bio *, int);
};

/*
 * Disable DIO read nolock optimization, so new dio readers will be forced
 * to grab i_mutex. It is used to avoid the endless truncate due to
 * nonlocked dio read.
 */
static inline void btrfs_inode_block_unlocked_dio(struct inode *inode)
{
        set_bit(BTRFS_INODE_READDIO_NEED_LOCK, &BTRFS_I(inode)->runtime_flags);
        smp_mb();
}

static inline void btrfs_inode_resume_unlocked_dio(struct inode *inode)
{
        smp_mb__before_atomic();
        clear_bit(BTRFS_INODE_READDIO_NEED_LOCK,
                  &BTRFS_I(inode)->runtime_flags);
}

bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end);

#endif