xref: /linux/fs/gfs2/meta_io.h (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 extern void gfs2_remove_from_journal(struct buffer_head *bh,
61 				     struct gfs2_trans *tr, int meta);
62 extern void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen);
63 extern int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
64 				     struct buffer_head **bhp);
65 
66 static 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 
72 struct 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