1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
/*
* gcinode.c - dummy inodes to buffer blocks for garbage collection
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Written by Seiji Kihara <kihara@osrg.net>, Amagai Yoshiji <amagai@osrg.net>,
* and Ryusuke Konishi <ryusuke@osrg.net>.
* Revised by Ryusuke Konishi <ryusuke@osrg.net>.
*
*/
/*
* This file adds the cache of on-disk blocks to be moved in garbage
* collection. The disk blocks are held with dummy inodes (called
* gcinodes), and this file provides lookup function of the dummy
* inodes and their buffer read function.
*
* Buffers and pages held by the dummy inodes will be released each
* time after they are copied to a new log. Dirty blocks made on the
* current generation and the blocks to be moved by GC never overlap
* because the dirty blocks make a new generation; they rather must be
* written individually.
*/
#include <linux/buffer_head.h>
#include <linux/mpage.h>
#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include "nilfs.h"
#include "btree.h"
#include "btnode.h"
#include "page.h"
#include "mdt.h"
#include "dat.h"
#include "ifile.h"
/*
* nilfs_gccache_submit_read_data() - add data buffer and submit read request
* @inode - gc inode
* @blkoff - dummy offset treated as the key for the page cache
* @pbn - physical block number of the block
* @vbn - virtual block number of the block, 0 for non-virtual block
* @out_bh - indirect pointer to a buffer_head struct to receive the results
*
* Description: nilfs_gccache_submit_read_data() registers the data buffer
* specified by @pbn to the GC pagecache with the key @blkoff.
* This function sets @vbn (@pbn if @vbn is zero) in b_blocknr of the buffer.
*
* Return Value: On success, 0 is returned. On Error, one of the following
* negative error code is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-ENOENT - The block specified with @pbn does not exist.
*/
int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff,
sector_t pbn, __u64 vbn,
struct buffer_head **out_bh)
{
struct buffer_head *bh;
int err;
bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
if (unlikely(!bh))
return -ENOMEM;
if (buffer_uptodate(bh))
goto out;
if (pbn == 0) {
struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
err = nilfs_dat_translate(nilfs->ns_dat, vbn, &pbn);
if (unlikely(err)) { /* -EIO, -ENOMEM, -ENOENT */
brelse(bh);
goto failed;
}
}
lock_buffer(bh);
if (buffer_uptodate(bh)) {
unlock_buffer(bh);
goto out;
}
if (!buffer_mapped(bh)) {
bh->b_bdev = inode->i_sb->s_bdev;
set_buffer_mapped(bh);
}
bh->b_blocknr = pbn;
bh->b_end_io = end_buffer_read_sync;
get_bh(bh);
submit_bh(READ, bh);
if (vbn)
bh->b_blocknr = vbn;
out:
err = 0;
*out_bh = bh;
failed:
unlock_page(bh->b_page);
page_cache_release(bh->b_page);
return err;
}
/*
* nilfs_gccache_submit_read_node() - add node buffer and submit read request
* @inode - gc inode
* @pbn - physical block number for the block
* @vbn - virtual block number for the block
* @out_bh - indirect pointer to a buffer_head struct to receive the results
*
* Description: nilfs_gccache_submit_read_node() registers the node buffer
* specified by @vbn to the GC pagecache. @pbn can be supplied by the
* caller to avoid translation of the disk block address.
*
* Return Value: On success, 0 is returned. On Error, one of the following
* negative error code is returned.
*
* %-EIO - I/O error.
*
* %-ENOMEM - Insufficient amount of memory available.
*/
int nilfs_gccache_submit_read_node(struct inode *inode, sector_t pbn,
__u64 vbn, struct buffer_head **out_bh)
{
int ret;
ret = nilfs_btnode_submit_block(&NILFS_I(inode)->i_btnode_cache,
vbn ? : pbn, pbn, READ, out_bh, &pbn);
if (ret == -EEXIST) /* internal code (cache hit) */
ret = 0;
return ret;
}
int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *bh)
{
wait_on_buffer(bh);
if (!buffer_uptodate(bh))
return -EIO;
if (buffer_dirty(bh))
return -EEXIST;
if (buffer_nilfs_node(bh)) {
if (nilfs_btree_broken_node_block(bh)) {
clear_buffer_uptodate(bh);
return -EIO;
}
nilfs_btnode_mark_dirty(bh);
} else {
nilfs_mark_buffer_dirty(bh);
}
return 0;
}
int nilfs_init_gcinode(struct inode *inode)
{
struct nilfs_inode_info *ii = NILFS_I(inode);
inode->i_mode = S_IFREG;
mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
inode->i_mapping->a_ops = &empty_aops;
inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
ii->i_flags = 0;
nilfs_bmap_init_gc(ii->i_bmap);
return 0;
}
/**
* nilfs_remove_all_gcinodes() - remove all unprocessed gc inodes
*/
void nilfs_remove_all_gcinodes(struct the_nilfs *nilfs)
{
struct list_head *head = &nilfs->ns_gc_inodes;
struct nilfs_inode_info *ii;
while (!list_empty(head)) {
ii = list_first_entry(head, struct nilfs_inode_info, i_dirty);
list_del_init(&ii->i_dirty);
iput(&ii->vfs_inode);
}
}
|
