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Ryusuke Konishia3d93f72009-04-06 19:01:40 -07001/*
Ryusuke Konishi047180f2009-04-06 19:01:45 -07002 * gcinode.c - dummy inodes to buffer blocks for garbage collection
Ryusuke Konishia3d93f72009-04-06 19:01:40 -07003 *
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 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *
20 * Written by Seiji Kihara <kihara@osrg.net>, Amagai Yoshiji <amagai@osrg.net>,
21 * and Ryusuke Konishi <ryusuke@osrg.net>.
22 * Revised by Ryusuke Konishi <ryusuke@osrg.net>.
23 *
24 */
Ryusuke Konishi047180f2009-04-06 19:01:45 -070025/*
26 * This file adds the cache of on-disk blocks to be moved in garbage
27 * collection. The disk blocks are held with dummy inodes (called
28 * gcinodes), and this file provides lookup function of the dummy
29 * inodes and their buffer read function.
30 *
Ryusuke Konishi047180f2009-04-06 19:01:45 -070031 * Buffers and pages held by the dummy inodes will be released each
32 * time after they are copied to a new log. Dirty blocks made on the
33 * current generation and the blocks to be moved by GC never overlap
34 * because the dirty blocks make a new generation; they rather must be
35 * written individually.
36 */
Ryusuke Konishia3d93f72009-04-06 19:01:40 -070037
38#include <linux/buffer_head.h>
39#include <linux/mpage.h>
40#include <linux/hash.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090041#include <linux/slab.h>
Ryusuke Konishia3d93f72009-04-06 19:01:40 -070042#include <linux/swap.h>
43#include "nilfs.h"
Ryusuke Konishi05d0e942010-07-10 20:52:09 +090044#include "btree.h"
45#include "btnode.h"
Ryusuke Konishia3d93f72009-04-06 19:01:40 -070046#include "page.h"
47#include "mdt.h"
48#include "dat.h"
49#include "ifile.h"
50
Ryusuke Konishia3d93f72009-04-06 19:01:40 -070051/*
52 * nilfs_gccache_submit_read_data() - add data buffer and submit read request
53 * @inode - gc inode
54 * @blkoff - dummy offset treated as the key for the page cache
55 * @pbn - physical block number of the block
56 * @vbn - virtual block number of the block, 0 for non-virtual block
57 * @out_bh - indirect pointer to a buffer_head struct to receive the results
58 *
59 * Description: nilfs_gccache_submit_read_data() registers the data buffer
60 * specified by @pbn to the GC pagecache with the key @blkoff.
61 * This function sets @vbn (@pbn if @vbn is zero) in b_blocknr of the buffer.
62 *
63 * Return Value: On success, 0 is returned. On Error, one of the following
64 * negative error code is returned.
65 *
66 * %-EIO - I/O error.
67 *
68 * %-ENOMEM - Insufficient amount of memory available.
69 *
70 * %-ENOENT - The block specified with @pbn does not exist.
71 */
72int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff,
73 sector_t pbn, __u64 vbn,
74 struct buffer_head **out_bh)
75{
76 struct buffer_head *bh;
77 int err;
78
79 bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
80 if (unlikely(!bh))
81 return -ENOMEM;
82
83 if (buffer_uptodate(bh))
84 goto out;
85
86 if (pbn == 0) {
Ryusuke Konishi0ef28f92011-05-05 12:56:51 +090087 struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
88
89 err = nilfs_dat_translate(nilfs->ns_dat, vbn, &pbn);
Ryusuke Konishia3d93f72009-04-06 19:01:40 -070090 if (unlikely(err)) { /* -EIO, -ENOMEM, -ENOENT */
91 brelse(bh);
92 goto failed;
93 }
94 }
95
96 lock_buffer(bh);
97 if (buffer_uptodate(bh)) {
98 unlock_buffer(bh);
99 goto out;
100 }
101
102 if (!buffer_mapped(bh)) {
Ryusuke Konishi0ef28f92011-05-05 12:56:51 +0900103 bh->b_bdev = inode->i_sb->s_bdev;
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700104 set_buffer_mapped(bh);
105 }
106 bh->b_blocknr = pbn;
107 bh->b_end_io = end_buffer_read_sync;
108 get_bh(bh);
109 submit_bh(READ, bh);
110 if (vbn)
111 bh->b_blocknr = vbn;
112 out:
113 err = 0;
114 *out_bh = bh;
115
116 failed:
117 unlock_page(bh->b_page);
118 page_cache_release(bh->b_page);
119 return err;
120}
121
122/*
123 * nilfs_gccache_submit_read_node() - add node buffer and submit read request
124 * @inode - gc inode
125 * @pbn - physical block number for the block
126 * @vbn - virtual block number for the block
127 * @out_bh - indirect pointer to a buffer_head struct to receive the results
128 *
129 * Description: nilfs_gccache_submit_read_node() registers the node buffer
130 * specified by @vbn to the GC pagecache. @pbn can be supplied by the
131 * caller to avoid translation of the disk block address.
132 *
133 * Return Value: On success, 0 is returned. On Error, one of the following
134 * negative error code is returned.
135 *
136 * %-EIO - I/O error.
137 *
138 * %-ENOMEM - Insufficient amount of memory available.
139 */
140int nilfs_gccache_submit_read_node(struct inode *inode, sector_t pbn,
141 __u64 vbn, struct buffer_head **out_bh)
142{
Ryusuke Konishi26dfdd82010-07-18 10:42:23 +0900143 int ret;
144
145 ret = nilfs_btnode_submit_block(&NILFS_I(inode)->i_btnode_cache,
146 vbn ? : pbn, pbn, READ, out_bh, &pbn);
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700147 if (ret == -EEXIST) /* internal code (cache hit) */
148 ret = 0;
149 return ret;
150}
151
152int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *bh)
153{
154 wait_on_buffer(bh);
155 if (!buffer_uptodate(bh))
156 return -EIO;
157 if (buffer_dirty(bh))
158 return -EEXIST;
159
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +0900160 if (buffer_nilfs_node(bh) && nilfs_btree_broken_node_block(bh)) {
161 clear_buffer_uptodate(bh);
162 return -EIO;
Ryusuke Konishi1d5385b2010-07-16 23:52:40 +0900163 }
Ryusuke Konishi5fc7b142011-05-05 12:56:51 +0900164 mark_buffer_dirty(bh);
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700165 return 0;
166}
167
Ryusuke Konishi263d90c2010-08-20 19:06:11 +0900168int nilfs_init_gcinode(struct inode *inode)
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700169{
Ryusuke Konishi263d90c2010-08-20 19:06:11 +0900170 struct nilfs_inode_info *ii = NILFS_I(inode);
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700171
Ryusuke Konishiadbb39b2010-09-05 10:14:43 +0900172 inode->i_mode = S_IFREG;
173 mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
Ryusuke Konishi293ce0e2011-05-05 12:56:51 +0900174 inode->i_mapping->a_ops = &empty_aops;
Ryusuke Konishiadbb39b2010-09-05 10:14:43 +0900175 inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700176
Ryusuke Konishiadbb39b2010-09-05 10:14:43 +0900177 ii->i_flags = 0;
178 nilfs_bmap_init_gc(ii->i_bmap);
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700179
Ryusuke Konishiadbb39b2010-09-05 10:14:43 +0900180 return 0;
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700181}
182
Ryusuke Konishi263d90c2010-08-20 19:06:11 +0900183/**
184 * nilfs_remove_all_gcinodes() - remove all unprocessed gc inodes
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700185 */
Ryusuke Konishi263d90c2010-08-20 19:06:11 +0900186void nilfs_remove_all_gcinodes(struct the_nilfs *nilfs)
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700187{
Ryusuke Konishi263d90c2010-08-20 19:06:11 +0900188 struct list_head *head = &nilfs->ns_gc_inodes;
189 struct nilfs_inode_info *ii;
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700190
Ryusuke Konishi263d90c2010-08-20 19:06:11 +0900191 while (!list_empty(head)) {
192 ii = list_first_entry(head, struct nilfs_inode_info, i_dirty);
193 list_del_init(&ii->i_dirty);
194 iput(&ii->vfs_inode);
Ryusuke Konishia3d93f72009-04-06 19:01:40 -0700195 }
196}