LXR linux/fs/gfs2/meta

   1/*
   2 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4 *
   5 * This copyrighted material is made available to anyone wishing to use,
   6 * modify, copy, or redistribute it subject to the terms and conditions
   7 * of the GNU General Public License version 2.
   8 */
   9
  10#ifndef __DIO_DOT_H__
  11#define __DIO_DOT_H__
  12
  13#include <linux/buffer_head.h>
  14#include <linux/string.h>
  15#include "incore.h"
  16
  17static inline void gfs2_buffer_clear(struct buffer_head *bh)
  18{
  19        memset(bh->b_data, 0, bh->b_size);
  20}
  21
  22static inline void gfs2_buffer_clear_tail(struct buffer_head *bh, int head)
  23{
  24        BUG_ON(head > bh->b_size);
  25        memset(bh->b_data + head, 0, bh->b_size - head);
  26}
  27
  28static inline void gfs2_buffer_copy_tail(struct buffer_head *to_bh,
  29                                         int to_head,
  30                                         struct buffer_head *from_bh,
  31                                         int from_head)
  32{
  33        BUG_ON(from_head < to_head);
  34        memcpy(to_bh->b_data + to_head, from_bh->b_data + from_head,
  35               from_bh->b_size - from_head);
  36        memset(to_bh->b_data + to_bh->b_size + to_head - from_head,
  37               0, from_head - to_head);
  38}
  39
  40extern const struct address_space_operations gfs2_meta_aops;
  41extern const struct address_space_operations gfs2_rgrp_aops;
  42
  43static inline struct gfs2_sbd *gfs2_mapping2sbd(struct address_space *mapping)
  44{
  45        struct inode *inode = mapping->host;
  46        if (mapping->a_ops == &gfs2_meta_aops)
  47                return (((struct gfs2_glock *)mapping) - 1)->gl_sbd;
  48        else if (mapping->a_ops == &gfs2_rgrp_aops)
  49                return container_of(mapping, struct gfs2_sbd, sd_aspace);
  50        else
  51                return inode->i_sb->s_fs_info;
  52}
  53
  54extern struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno);
  55extern int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
  56                          struct buffer_head **bhp);
  57extern int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh);
  58extern struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno,
  59                                       int create);
  60extern void gfs2_remove_from_journal(struct buffer_head *bh,
  61                                     struct gfs2_trans *tr, int meta);
  62extern void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen);
  63extern int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
  64                                     struct buffer_head **bhp);
  65
  66static inline int gfs2_meta_inode_buffer(struct gfs2_inode *ip,
  67                                         struct buffer_head **bhp)
  68{
  69        return gfs2_meta_indirect_buffer(ip, 0, ip->i_no_addr, bhp);
  70}
  71
  72struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen);
  73
  74#define buffer_busy(bh) \
  75((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock) | (1ul << BH_Pinned)))
  76
  77#endif /* __DIO_DOT_H__ */
  78
  79