2 * gcinode.c - dummy inodes to buffer blocks for garbage collection
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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.
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.
16 * Written by Seiji Kihara, Amagai Yoshiji, and Ryusuke Konishi.
17 * Revised by Ryusuke Konishi.
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.
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.
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>
47 * nilfs_gccache_submit_read_data() - add data buffer and submit read request
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
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.
58 * Return Value: On success, 0 is returned. On Error, one of the following
59 * negative error code is returned.
63 * %-ENOMEM - Insufficient amount of memory available.
65 * %-ENOENT - The block specified with @pbn does not exist.
67 int nilfs_gccache_submit_read_data(struct inode
*inode
, sector_t blkoff
,
68 sector_t pbn
, __u64 vbn
,
69 struct buffer_head
**out_bh
)
71 struct buffer_head
*bh
;
74 bh
= nilfs_grab_buffer(inode
, inode
->i_mapping
, blkoff
, 0);
78 if (buffer_uptodate(bh
))
82 struct the_nilfs
*nilfs
= inode
->i_sb
->s_fs_info
;
84 err
= nilfs_dat_translate(nilfs
->ns_dat
, vbn
, &pbn
);
85 if (unlikely(err
)) { /* -EIO, -ENOMEM, -ENOENT */
92 if (buffer_uptodate(bh
)) {
97 if (!buffer_mapped(bh
)) {
98 bh
->b_bdev
= inode
->i_sb
->s_bdev
;
99 set_buffer_mapped(bh
);
102 bh
->b_end_io
= end_buffer_read_sync
;
112 unlock_page(bh
->b_page
);
113 put_page(bh
->b_page
);
118 * nilfs_gccache_submit_read_node() - add node buffer and submit read request
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
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.
128 * Return Value: On success, 0 is returned. On Error, one of the following
129 * negative error code is returned.
133 * %-ENOMEM - Insufficient amount of memory available.
135 int nilfs_gccache_submit_read_node(struct inode
*inode
, sector_t pbn
,
136 __u64 vbn
, struct buffer_head
**out_bh
)
140 ret
= nilfs_btnode_submit_block(&NILFS_I(inode
)->i_btnode_cache
,
141 vbn
? : pbn
, pbn
, READ
, out_bh
, &pbn
);
142 if (ret
== -EEXIST
) /* internal code (cache hit) */
147 int nilfs_gccache_wait_and_mark_dirty(struct buffer_head
*bh
)
150 if (!buffer_uptodate(bh
))
152 if (buffer_dirty(bh
))
155 if (buffer_nilfs_node(bh
) && nilfs_btree_broken_node_block(bh
)) {
156 clear_buffer_uptodate(bh
);
159 mark_buffer_dirty(bh
);
163 int nilfs_init_gcinode(struct inode
*inode
)
165 struct nilfs_inode_info
*ii
= NILFS_I(inode
);
167 inode
->i_mode
= S_IFREG
;
168 mapping_set_gfp_mask(inode
->i_mapping
, GFP_NOFS
);
169 inode
->i_mapping
->a_ops
= &empty_aops
;
172 nilfs_bmap_init_gc(ii
->i_bmap
);
178 * nilfs_remove_all_gcinodes() - remove all unprocessed gc inodes
180 void nilfs_remove_all_gcinodes(struct the_nilfs
*nilfs
)
182 struct list_head
*head
= &nilfs
->ns_gc_inodes
;
183 struct nilfs_inode_info
*ii
;
185 while (!list_empty(head
)) {
186 ii
= list_first_entry(head
, struct nilfs_inode_info
, i_dirty
);
187 list_del_init(&ii
->i_dirty
);
188 truncate_inode_pages(&ii
->vfs_inode
.i_data
, 0);
189 nilfs_btnode_cache_clear(&ii
->i_btnode_cache
);
190 iput(&ii
->vfs_inode
);
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