1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Dummy inodes to buffer blocks for garbage collection |
4 | * |
5 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
6 | * |
7 | * Written by Seiji Kihara, Amagai Yoshiji, and Ryusuke Konishi. |
8 | * Revised by Ryusuke Konishi. |
9 | * |
10 | */ |
11 | /* |
12 | * This file adds the cache of on-disk blocks to be moved in garbage |
13 | * collection. The disk blocks are held with dummy inodes (called |
14 | * gcinodes), and this file provides lookup function of the dummy |
15 | * inodes and their buffer read function. |
16 | * |
17 | * Buffers and pages held by the dummy inodes will be released each |
18 | * time after they are copied to a new log. Dirty blocks made on the |
19 | * current generation and the blocks to be moved by GC never overlap |
20 | * because the dirty blocks make a new generation; they rather must be |
21 | * written individually. |
22 | */ |
23 | |
24 | #include <linux/buffer_head.h> |
25 | #include <linux/mpage.h> |
26 | #include <linux/hash.h> |
27 | #include <linux/slab.h> |
28 | #include <linux/swap.h> |
29 | #include "nilfs.h" |
30 | #include "btree.h" |
31 | #include "btnode.h" |
32 | #include "page.h" |
33 | #include "mdt.h" |
34 | #include "dat.h" |
35 | #include "ifile.h" |
36 | |
37 | /* |
38 | * nilfs_gccache_submit_read_data() - add data buffer and submit read request |
39 | * @inode - gc inode |
40 | * @blkoff - dummy offset treated as the key for the page cache |
41 | * @pbn - physical block number of the block |
42 | * @vbn - virtual block number of the block, 0 for non-virtual block |
43 | * @out_bh - indirect pointer to a buffer_head struct to receive the results |
44 | * |
45 | * Description: nilfs_gccache_submit_read_data() registers the data buffer |
46 | * specified by @pbn to the GC pagecache with the key @blkoff. |
47 | * This function sets @vbn (@pbn if @vbn is zero) in b_blocknr of the buffer. |
48 | * |
49 | * Return Value: On success, 0 is returned. On Error, one of the following |
50 | * negative error code is returned. |
51 | * |
52 | * %-EIO - I/O error. |
53 | * |
54 | * %-ENOMEM - Insufficient amount of memory available. |
55 | * |
56 | * %-ENOENT - The block specified with @pbn does not exist. |
57 | */ |
58 | int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff, |
59 | sector_t pbn, __u64 vbn, |
60 | struct buffer_head **out_bh) |
61 | { |
62 | struct buffer_head *bh; |
63 | int err; |
64 | |
65 | bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0); |
66 | if (unlikely(!bh)) |
67 | return -ENOMEM; |
68 | |
69 | if (buffer_uptodate(bh)) |
70 | goto out; |
71 | |
72 | if (pbn == 0) { |
73 | struct the_nilfs *nilfs = inode->i_sb->s_fs_info; |
74 | |
75 | err = nilfs_dat_translate(nilfs->ns_dat, vbn, &pbn); |
76 | if (unlikely(err)) /* -EIO, -ENOMEM, -ENOENT */ |
77 | goto failed; |
78 | } |
79 | |
80 | lock_buffer(bh); |
81 | if (buffer_uptodate(bh)) { |
82 | unlock_buffer(bh); |
83 | goto out; |
84 | } |
85 | |
86 | if (!buffer_mapped(bh)) { |
87 | bh->b_bdev = inode->i_sb->s_bdev; |
88 | set_buffer_mapped(bh); |
89 | } |
90 | bh->b_blocknr = pbn; |
91 | bh->b_end_io = end_buffer_read_sync; |
92 | get_bh(bh); |
93 | submit_bh(REQ_OP_READ, bh); |
94 | if (vbn) |
95 | bh->b_blocknr = vbn; |
96 | out: |
97 | err = 0; |
98 | *out_bh = bh; |
99 | |
100 | failed: |
101 | unlock_page(page: bh->b_page); |
102 | put_page(page: bh->b_page); |
103 | if (unlikely(err)) |
104 | brelse(bh); |
105 | return err; |
106 | } |
107 | |
108 | /* |
109 | * nilfs_gccache_submit_read_node() - add node buffer and submit read request |
110 | * @inode - gc inode |
111 | * @pbn - physical block number for the block |
112 | * @vbn - virtual block number for the block |
113 | * @out_bh - indirect pointer to a buffer_head struct to receive the results |
114 | * |
115 | * Description: nilfs_gccache_submit_read_node() registers the node buffer |
116 | * specified by @vbn to the GC pagecache. @pbn can be supplied by the |
117 | * caller to avoid translation of the disk block address. |
118 | * |
119 | * Return Value: On success, 0 is returned. On Error, one of the following |
120 | * negative error code is returned. |
121 | * |
122 | * %-EIO - I/O error. |
123 | * |
124 | * %-ENOMEM - Insufficient amount of memory available. |
125 | */ |
126 | int nilfs_gccache_submit_read_node(struct inode *inode, sector_t pbn, |
127 | __u64 vbn, struct buffer_head **out_bh) |
128 | { |
129 | struct inode *btnc_inode = NILFS_I(inode)->i_assoc_inode; |
130 | int ret; |
131 | |
132 | ret = nilfs_btnode_submit_block(btnc_inode->i_mapping, vbn ? : pbn, pbn, |
133 | REQ_OP_READ, out_bh, &pbn); |
134 | if (ret == -EEXIST) /* internal code (cache hit) */ |
135 | ret = 0; |
136 | return ret; |
137 | } |
138 | |
139 | int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *bh) |
140 | { |
141 | wait_on_buffer(bh); |
142 | if (!buffer_uptodate(bh)) { |
143 | struct inode *inode = bh->b_folio->mapping->host; |
144 | |
145 | nilfs_err(inode->i_sb, |
146 | "I/O error reading %s block for GC (ino=%lu, vblocknr=%llu)" , |
147 | buffer_nilfs_node(bh) ? "node" : "data" , |
148 | inode->i_ino, (unsigned long long)bh->b_blocknr); |
149 | return -EIO; |
150 | } |
151 | if (buffer_dirty(bh)) |
152 | return -EEXIST; |
153 | |
154 | if (buffer_nilfs_node(bh) && nilfs_btree_broken_node_block(bh)) { |
155 | clear_buffer_uptodate(bh); |
156 | return -EIO; |
157 | } |
158 | mark_buffer_dirty(bh); |
159 | return 0; |
160 | } |
161 | |
162 | int nilfs_init_gcinode(struct inode *inode) |
163 | { |
164 | struct nilfs_inode_info *ii = NILFS_I(inode); |
165 | |
166 | inode->i_mode = S_IFREG; |
167 | mapping_set_gfp_mask(m: inode->i_mapping, GFP_NOFS); |
168 | inode->i_mapping->a_ops = &empty_aops; |
169 | |
170 | ii->i_flags = 0; |
171 | nilfs_bmap_init_gc(ii->i_bmap); |
172 | |
173 | return nilfs_attach_btree_node_cache(inode); |
174 | } |
175 | |
176 | /** |
177 | * nilfs_remove_all_gcinodes() - remove all unprocessed gc inodes |
178 | */ |
179 | void nilfs_remove_all_gcinodes(struct the_nilfs *nilfs) |
180 | { |
181 | struct list_head *head = &nilfs->ns_gc_inodes; |
182 | struct nilfs_inode_info *ii; |
183 | |
184 | while (!list_empty(head)) { |
185 | ii = list_first_entry(head, struct nilfs_inode_info, i_dirty); |
186 | list_del_init(entry: &ii->i_dirty); |
187 | truncate_inode_pages(&ii->vfs_inode.i_data, 0); |
188 | nilfs_btnode_cache_clear(ii->i_assoc_inode->i_mapping); |
189 | iput(&ii->vfs_inode); |
190 | } |
191 | } |
192 | |