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