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