xref: /openbmc/linux/fs/nilfs2/ifile.c (revision 3b64b188)
1 /*
2  * ifile.c - NILFS inode file
3  *
4  * Copyright (C) 2006-2008 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 Amagai Yoshiji <amagai@osrg.net>.
21  * Revised by Ryusuke Konishi <ryusuke@osrg.net>.
22  *
23  */
24 
25 #include <linux/types.h>
26 #include <linux/buffer_head.h>
27 #include "nilfs.h"
28 #include "mdt.h"
29 #include "alloc.h"
30 #include "ifile.h"
31 
32 /**
33  * struct nilfs_ifile_info - on-memory private data of ifile
34  * @mi: on-memory private data of metadata file
35  * @palloc_cache: persistent object allocator cache of ifile
36  */
37 struct nilfs_ifile_info {
38 	struct nilfs_mdt_info mi;
39 	struct nilfs_palloc_cache palloc_cache;
40 };
41 
42 static inline struct nilfs_ifile_info *NILFS_IFILE_I(struct inode *ifile)
43 {
44 	return (struct nilfs_ifile_info *)NILFS_MDT(ifile);
45 }
46 
47 /**
48  * nilfs_ifile_create_inode - create a new disk inode
49  * @ifile: ifile inode
50  * @out_ino: pointer to a variable to store inode number
51  * @out_bh: buffer_head contains newly allocated disk inode
52  *
53  * Return Value: On success, 0 is returned and the newly allocated inode
54  * number is stored in the place pointed by @ino, and buffer_head pointer
55  * that contains newly allocated disk inode structure is stored in the
56  * place pointed by @out_bh
57  * On error, one of the following negative error codes is returned.
58  *
59  * %-EIO - I/O error.
60  *
61  * %-ENOMEM - Insufficient amount of memory available.
62  *
63  * %-ENOSPC - No inode left.
64  */
65 int nilfs_ifile_create_inode(struct inode *ifile, ino_t *out_ino,
66 			     struct buffer_head **out_bh)
67 {
68 	struct nilfs_palloc_req req;
69 	int ret;
70 
71 	req.pr_entry_nr = 0;  /* 0 says find free inode from beginning of
72 				 a group. dull code!! */
73 	req.pr_entry_bh = NULL;
74 
75 	ret = nilfs_palloc_prepare_alloc_entry(ifile, &req);
76 	if (!ret) {
77 		ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 1,
78 						   &req.pr_entry_bh);
79 		if (ret < 0)
80 			nilfs_palloc_abort_alloc_entry(ifile, &req);
81 	}
82 	if (ret < 0) {
83 		brelse(req.pr_entry_bh);
84 		return ret;
85 	}
86 	nilfs_palloc_commit_alloc_entry(ifile, &req);
87 	mark_buffer_dirty(req.pr_entry_bh);
88 	nilfs_mdt_mark_dirty(ifile);
89 	*out_ino = (ino_t)req.pr_entry_nr;
90 	*out_bh = req.pr_entry_bh;
91 	return 0;
92 }
93 
94 /**
95  * nilfs_ifile_delete_inode - delete a disk inode
96  * @ifile: ifile inode
97  * @ino: inode number
98  *
99  * Return Value: On success, 0 is returned. On error, one of the following
100  * negative error codes is returned.
101  *
102  * %-EIO - I/O error.
103  *
104  * %-ENOMEM - Insufficient amount of memory available.
105  *
106  * %-ENOENT - The inode number @ino have not been allocated.
107  */
108 int nilfs_ifile_delete_inode(struct inode *ifile, ino_t ino)
109 {
110 	struct nilfs_palloc_req req = {
111 		.pr_entry_nr = ino, .pr_entry_bh = NULL
112 	};
113 	struct nilfs_inode *raw_inode;
114 	void *kaddr;
115 	int ret;
116 
117 	ret = nilfs_palloc_prepare_free_entry(ifile, &req);
118 	if (!ret) {
119 		ret = nilfs_palloc_get_entry_block(ifile, req.pr_entry_nr, 0,
120 						   &req.pr_entry_bh);
121 		if (ret < 0)
122 			nilfs_palloc_abort_free_entry(ifile, &req);
123 	}
124 	if (ret < 0) {
125 		brelse(req.pr_entry_bh);
126 		return ret;
127 	}
128 
129 	kaddr = kmap_atomic(req.pr_entry_bh->b_page);
130 	raw_inode = nilfs_palloc_block_get_entry(ifile, req.pr_entry_nr,
131 						 req.pr_entry_bh, kaddr);
132 	raw_inode->i_flags = 0;
133 	kunmap_atomic(kaddr);
134 
135 	mark_buffer_dirty(req.pr_entry_bh);
136 	brelse(req.pr_entry_bh);
137 
138 	nilfs_palloc_commit_free_entry(ifile, &req);
139 
140 	return 0;
141 }
142 
143 int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
144 				struct buffer_head **out_bh)
145 {
146 	struct super_block *sb = ifile->i_sb;
147 	int err;
148 
149 	if (unlikely(!NILFS_VALID_INODE(sb, ino))) {
150 		nilfs_error(sb, __func__, "bad inode number: %lu",
151 			    (unsigned long) ino);
152 		return -EINVAL;
153 	}
154 
155 	err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh);
156 	if (unlikely(err))
157 		nilfs_warning(sb, __func__, "unable to read inode: %lu",
158 			      (unsigned long) ino);
159 	return err;
160 }
161 
162 /**
163  * nilfs_ifile_read - read or get ifile inode
164  * @sb: super block instance
165  * @root: root object
166  * @inode_size: size of an inode
167  * @raw_inode: on-disk ifile inode
168  * @inodep: buffer to store the inode
169  */
170 int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,
171 		     size_t inode_size, struct nilfs_inode *raw_inode,
172 		     struct inode **inodep)
173 {
174 	struct inode *ifile;
175 	int err;
176 
177 	ifile = nilfs_iget_locked(sb, root, NILFS_IFILE_INO);
178 	if (unlikely(!ifile))
179 		return -ENOMEM;
180 	if (!(ifile->i_state & I_NEW))
181 		goto out;
182 
183 	err = nilfs_mdt_init(ifile, NILFS_MDT_GFP,
184 			     sizeof(struct nilfs_ifile_info));
185 	if (err)
186 		goto failed;
187 
188 	err = nilfs_palloc_init_blockgroup(ifile, inode_size);
189 	if (err)
190 		goto failed;
191 
192 	nilfs_palloc_setup_cache(ifile, &NILFS_IFILE_I(ifile)->palloc_cache);
193 
194 	err = nilfs_read_inode_common(ifile, raw_inode);
195 	if (err)
196 		goto failed;
197 
198 	unlock_new_inode(ifile);
199  out:
200 	*inodep = ifile;
201 	return 0;
202  failed:
203 	iget_failed(ifile);
204 	return err;
205 }
206