btrfs_inode.h

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/*
 * 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 "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

/* 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 */
    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;

    /*
     * list for tracking inodes that must be sent to disk before a
     * rename or truncate commit
     */
    struct list_head ordered_operations;

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

    unsigned long runtime_flags;

    /* 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;

    /*
     * log transid when this inode was last modified
     */
    u64 last_sub_trans;

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

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

    /* 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;

    /* a local copy of root's last_log_commit */
    unsigned long last_log_commit;

    /*
     * 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;

    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 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)
{
    if (BTRFS_I(inode)->logged_trans == generation &&
        BTRFS_I(inode)->last_sub_trans <= BTRFS_I(inode)->last_log_commit)
        return 1;
    return 0;
}

#endif