xref: /openbmc/linux/fs/ocfs2/buffer_head_io.h (revision e3b9f1e8)
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * ocfs2_buffer_head.h
5  *
6  * Buffer cache handling functions defined
7  *
8  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public
12  * License as published by the Free Software Foundation; either
13  * version 2 of the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public
21  * License along with this program; if not, write to the
22  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23  * Boston, MA 021110-1307, USA.
24  */
25 
26 #ifndef OCFS2_BUFFER_HEAD_IO_H
27 #define OCFS2_BUFFER_HEAD_IO_H
28 
29 #include <linux/buffer_head.h>
30 
31 int ocfs2_write_block(struct ocfs2_super          *osb,
32 		      struct buffer_head  *bh,
33 		      struct ocfs2_caching_info   *ci);
34 int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
35 			   unsigned int nr, struct buffer_head *bhs[]);
36 
37 /*
38  * If not NULL, validate() will be called on a buffer that is freshly
39  * read from disk.  It will not be called if the buffer was in cache.
40  * Note that if validate() is being used for this buffer, it needs to
41  * be set even for a READAHEAD call, as it marks the buffer for later
42  * validation.
43  */
44 int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
45 		      struct buffer_head *bhs[], int flags,
46 		      int (*validate)(struct super_block *sb,
47 				      struct buffer_head *bh));
48 
49 int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
50 				struct buffer_head *bh);
51 
52 #define OCFS2_BH_IGNORE_CACHE      1
53 #define OCFS2_BH_READAHEAD         8
54 
55 static inline int ocfs2_read_block(struct ocfs2_caching_info *ci, u64 off,
56 				   struct buffer_head **bh,
57 				   int (*validate)(struct super_block *sb,
58 						   struct buffer_head *bh))
59 {
60 	int status = 0;
61 
62 	if (bh == NULL) {
63 		printk("ocfs2: bh == NULL\n");
64 		status = -EINVAL;
65 		goto bail;
66 	}
67 
68 	status = ocfs2_read_blocks(ci, off, 1, bh, 0, validate);
69 
70 bail:
71 	return status;
72 }
73 
74 #endif /* OCFS2_BUFFER_HEAD_IO_H */
75