fs/gfs2/meta_io.h

   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
  17 static inline void gfs2_buffer_clear(struct buffer_head *bh)
  18 {
  19         memset(bh->b_data, 0, bh->b_size);
  20 }
  21
  22 static 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
  28 static 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
  40 extern const struct address_space_operations gfs2_meta_aops;
  41 extern const struct address_space_operations gfs2_rgrp_aops;
  42
  43 static 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_name.ln_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
  54 extern struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno);
  55 extern int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
  56                           int rahead, struct buffer_head **bhp);
  57 extern int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh);
  58 extern struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno,
  59                                        int create);
  60 enum {
  61         REMOVE_JDATA = 0,
  62         REMOVE_META = 1,
  63 };
  64
  65 extern void gfs2_remove_from_journal(struct buffer_head *bh, int meta);
  66 extern void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen);
  67 extern int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
  68                                      struct buffer_head **bhp);
  69
  70 static inline int gfs2_meta_inode_buffer(struct gfs2_inode *ip,
  71                                          struct buffer_head **bhp)
  72 {
  73         return gfs2_meta_indirect_buffer(ip, 0, ip->i_no_addr, bhp);
  74 }
  75
  76 struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen);
  77
  78 #define buffer_busy(bh) \
  79 ((bh)->b_state & ((1ul << BH_Dirty) | (1ul << BH_Lock) | (1ul << BH_Pinned)))
  80
  81 #endif /* __DIO_DOT_H__ */
  82