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: 0 on success, or one of the following negative error codes on
50 * failure:
51 * * %-EIO - I/O error (including metadata corruption).
52 * * %-ENOENT - The block specified with @pbn does not exist.
53 * * %-ENOMEM - Insufficient memory available.
54 */
nilfs_gccache_submit_read_data(struct inode * inode,sector_t blkoff,sector_t pbn,__u64 vbn,struct buffer_head ** out_bh)55 int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff,
56 sector_t pbn, __u64 vbn,
57 struct buffer_head **out_bh)
58 {
59 struct buffer_head *bh;
60 int err;
61
62 bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
63 if (unlikely(!bh))
64 return -ENOMEM;
65
66 if (buffer_uptodate(bh))
67 goto out;
68
69 if (pbn == 0) {
70 struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
71
72 err = nilfs_dat_translate(nilfs->ns_dat, vbn, &pbn);
73 if (unlikely(err)) /* -EIO, -ENOMEM, -ENOENT */
74 goto failed;
75 }
76
77 lock_buffer(bh);
78 if (buffer_uptodate(bh)) {
79 unlock_buffer(bh);
80 goto out;
81 }
82
83 if (!buffer_mapped(bh))
84 set_buffer_mapped(bh);
85 bh->b_blocknr = pbn;
86 bh->b_end_io = end_buffer_read_sync;
87 get_bh(bh);
88 submit_bh(REQ_OP_READ, bh);
89 if (vbn)
90 bh->b_blocknr = vbn;
91 out:
92 err = 0;
93 *out_bh = bh;
94
95 failed:
96 folio_unlock(bh->b_folio);
97 folio_put(bh->b_folio);
98 if (unlikely(err))
99 brelse(bh);
100 return err;
101 }
102
103 /*
104 * nilfs_gccache_submit_read_node() - add node buffer and submit read request
105 * @inode - gc inode
106 * @pbn - physical block number for the block
107 * @vbn - virtual block number for the block
108 * @out_bh - indirect pointer to a buffer_head struct to receive the results
109 *
110 * Description: nilfs_gccache_submit_read_node() registers the node buffer
111 * specified by @vbn to the GC pagecache. @pbn can be supplied by the
112 * caller to avoid translation of the disk block address.
113 *
114 * Return: 0 on success, or one of the following negative error codes on
115 * failure:
116 * * %-EIO - I/O error (including metadata corruption).
117 * * %-ENOENT - Invalid virtual block address.
118 * * %-ENOMEM - Insufficient memory available.
119 */
nilfs_gccache_submit_read_node(struct inode * inode,sector_t pbn,__u64 vbn,struct buffer_head ** out_bh)120 int nilfs_gccache_submit_read_node(struct inode *inode, sector_t pbn,
121 __u64 vbn, struct buffer_head **out_bh)
122 {
123 struct inode *btnc_inode = NILFS_I(inode)->i_assoc_inode;
124 int ret;
125
126 ret = nilfs_btnode_submit_block(btnc_inode->i_mapping, vbn ? : pbn, pbn,
127 REQ_OP_READ, out_bh, &pbn);
128 if (ret == -EEXIST) /* internal code (cache hit) */
129 ret = 0;
130 return ret;
131 }
132
nilfs_gccache_wait_and_mark_dirty(struct buffer_head * bh)133 int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *bh)
134 {
135 wait_on_buffer(bh);
136 if (!buffer_uptodate(bh)) {
137 struct inode *inode = bh->b_folio->mapping->host;
138
139 nilfs_err(inode->i_sb,
140 "I/O error reading %s block for GC (ino=%lu, vblocknr=%llu)",
141 buffer_nilfs_node(bh) ? "node" : "data",
142 inode->i_ino, (unsigned long long)bh->b_blocknr);
143 return -EIO;
144 }
145 if (buffer_dirty(bh))
146 return -EEXIST;
147
148 if (buffer_nilfs_node(bh) && nilfs_btree_broken_node_block(bh)) {
149 clear_buffer_uptodate(bh);
150 return -EIO;
151 }
152 mark_buffer_dirty(bh);
153 return 0;
154 }
155
nilfs_init_gcinode(struct inode * inode)156 int nilfs_init_gcinode(struct inode *inode)
157 {
158 struct nilfs_inode_info *ii = NILFS_I(inode);
159
160 inode->i_mode = S_IFREG;
161 mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
162 inode->i_mapping->a_ops = &nilfs_buffer_cache_aops;
163
164 ii->i_flags = 0;
165 nilfs_bmap_init_gc(ii->i_bmap);
166
167 return nilfs_attach_btree_node_cache(inode);
168 }
169
170 /**
171 * nilfs_remove_all_gcinodes() - remove all unprocessed gc inodes
172 * @nilfs: NILFS filesystem instance
173 */
nilfs_remove_all_gcinodes(struct the_nilfs * nilfs)174 void nilfs_remove_all_gcinodes(struct the_nilfs *nilfs)
175 {
176 struct list_head *head = &nilfs->ns_gc_inodes;
177 struct nilfs_inode_info *ii;
178
179 while (!list_empty(head)) {
180 ii = list_first_entry(head, struct nilfs_inode_info, i_dirty);
181 list_del_init(&ii->i_dirty);
182 truncate_inode_pages(&ii->vfs_inode.i_data, 0);
183 nilfs_btnode_cache_clear(ii->i_assoc_inode->i_mapping);
184 iput(&ii->vfs_inode);
185 }
186 }
187