xref: /linux/fs/freevxfs/vxfs_super.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * Copyright (c) 2000-2001 Christoph Hellwig.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. The name of the author may not be used to endorse or promote products
12  *    derived from this software without specific prior written permission.
13  *
14  * Alternatively, this software may be distributed under the terms of the
15  * GNU General Public License ("GPL").
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Veritas filesystem driver - superblock related routines.
32  */
33 #include <linux/init.h>
34 #include <linux/module.h>
35 
36 #include <linux/blkdev.h>
37 #include <linux/fs.h>
38 #include <linux/buffer_head.h>
39 #include <linux/kernel.h>
40 #include <linux/slab.h>
41 #include <linux/stat.h>
42 #include <linux/vfs.h>
43 #include <linux/mount.h>
44 
45 #include "vxfs.h"
46 #include "vxfs_extern.h"
47 #include "vxfs_dir.h"
48 #include "vxfs_inode.h"
49 
50 
51 MODULE_AUTHOR("Christoph Hellwig");
52 MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
53 MODULE_LICENSE("Dual BSD/GPL");
54 
55 
56 
57 static void		vxfs_put_super(struct super_block *);
58 static int		vxfs_statfs(struct dentry *, struct kstatfs *);
59 static int		vxfs_remount(struct super_block *, int *, char *);
60 
61 static const struct super_operations vxfs_super_ops = {
62 	.evict_inode =		vxfs_evict_inode,
63 	.put_super =		vxfs_put_super,
64 	.statfs =		vxfs_statfs,
65 	.remount_fs =		vxfs_remount,
66 };
67 
68 /**
69  * vxfs_put_super - free superblock resources
70  * @sbp:	VFS superblock.
71  *
72  * Description:
73  *   vxfs_put_super frees all resources allocated for @sbp
74  *   after the last instance of the filesystem is unmounted.
75  */
76 
77 static void
78 vxfs_put_super(struct super_block *sbp)
79 {
80 	struct vxfs_sb_info	*infp = VXFS_SBI(sbp);
81 
82 	vxfs_put_fake_inode(infp->vsi_fship);
83 	vxfs_put_fake_inode(infp->vsi_ilist);
84 	vxfs_put_fake_inode(infp->vsi_stilist);
85 
86 	brelse(infp->vsi_bp);
87 	kfree(infp);
88 }
89 
90 /**
91  * vxfs_statfs - get filesystem information
92  * @dentry:	VFS dentry to locate superblock
93  * @bufp:	output buffer
94  *
95  * Description:
96  *   vxfs_statfs fills the statfs buffer @bufp with information
97  *   about the filesystem described by @dentry.
98  *
99  * Returns:
100  *   Zero.
101  *
102  * Locking:
103  *   No locks held.
104  *
105  * Notes:
106  *   This is everything but complete...
107  */
108 static int
109 vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
110 {
111 	struct vxfs_sb_info		*infp = VXFS_SBI(dentry->d_sb);
112 
113 	bufp->f_type = VXFS_SUPER_MAGIC;
114 	bufp->f_bsize = dentry->d_sb->s_blocksize;
115 	bufp->f_blocks = infp->vsi_raw->vs_dsize;
116 	bufp->f_bfree = infp->vsi_raw->vs_free;
117 	bufp->f_bavail = 0;
118 	bufp->f_files = 0;
119 	bufp->f_ffree = infp->vsi_raw->vs_ifree;
120 	bufp->f_namelen = VXFS_NAMELEN;
121 
122 	return 0;
123 }
124 
125 static int vxfs_remount(struct super_block *sb, int *flags, char *data)
126 {
127 	*flags |= MS_RDONLY;
128 	return 0;
129 }
130 
131 /**
132  * vxfs_read_super - read superblock into memory and initialize filesystem
133  * @sbp:		VFS superblock (to fill)
134  * @dp:			fs private mount data
135  * @silent:		do not complain loudly when sth is wrong
136  *
137  * Description:
138  *   We are called on the first mount of a filesystem to read the
139  *   superblock into memory and do some basic setup.
140  *
141  * Returns:
142  *   The superblock on success, else %NULL.
143  *
144  * Locking:
145  *   We are under @sbp->s_lock.
146  */
147 static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
148 {
149 	struct vxfs_sb_info	*infp;
150 	struct vxfs_sb		*rsbp;
151 	struct buffer_head	*bp = NULL;
152 	u_long			bsize;
153 	struct inode *root;
154 	int ret = -EINVAL;
155 
156 	sbp->s_flags |= MS_RDONLY;
157 
158 	infp = kzalloc(sizeof(*infp), GFP_KERNEL);
159 	if (!infp) {
160 		printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
161 		return -ENOMEM;
162 	}
163 
164 	bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
165 	if (!bsize) {
166 		printk(KERN_WARNING "vxfs: unable to set blocksize\n");
167 		goto out;
168 	}
169 
170 	bp = sb_bread(sbp, 1);
171 	if (!bp || !buffer_mapped(bp)) {
172 		if (!silent) {
173 			printk(KERN_WARNING
174 				"vxfs: unable to read disk superblock\n");
175 		}
176 		goto out;
177 	}
178 
179 	rsbp = (struct vxfs_sb *)bp->b_data;
180 	if (rsbp->vs_magic != VXFS_SUPER_MAGIC) {
181 		if (!silent)
182 			printk(KERN_NOTICE "vxfs: WRONG superblock magic\n");
183 		goto out;
184 	}
185 
186 	if ((rsbp->vs_version < 2 || rsbp->vs_version > 4) && !silent) {
187 		printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n",
188 		       rsbp->vs_version);
189 		goto out;
190 	}
191 
192 #ifdef DIAGNOSTIC
193 	printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", rsbp->vs_version);
194 	printk(KERN_DEBUG "vxfs: blocksize: %d\n", rsbp->vs_bsize);
195 #endif
196 
197 	sbp->s_magic = rsbp->vs_magic;
198 	sbp->s_fs_info = infp;
199 
200 	infp->vsi_raw = rsbp;
201 	infp->vsi_bp = bp;
202 	infp->vsi_oltext = rsbp->vs_oltext[0];
203 	infp->vsi_oltsize = rsbp->vs_oltsize;
204 
205 	if (!sb_set_blocksize(sbp, rsbp->vs_bsize)) {
206 		printk(KERN_WARNING "vxfs: unable to set final block size\n");
207 		goto out;
208 	}
209 
210 	if (vxfs_read_olt(sbp, bsize)) {
211 		printk(KERN_WARNING "vxfs: unable to read olt\n");
212 		goto out;
213 	}
214 
215 	if (vxfs_read_fshead(sbp)) {
216 		printk(KERN_WARNING "vxfs: unable to read fshead\n");
217 		goto out;
218 	}
219 
220 	sbp->s_op = &vxfs_super_ops;
221 	root = vxfs_iget(sbp, VXFS_ROOT_INO);
222 	if (IS_ERR(root)) {
223 		ret = PTR_ERR(root);
224 		goto out;
225 	}
226 	sbp->s_root = d_make_root(root);
227 	if (!sbp->s_root) {
228 		printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
229 		goto out_free_ilist;
230 	}
231 
232 	return 0;
233 
234 out_free_ilist:
235 	vxfs_put_fake_inode(infp->vsi_fship);
236 	vxfs_put_fake_inode(infp->vsi_ilist);
237 	vxfs_put_fake_inode(infp->vsi_stilist);
238 out:
239 	brelse(bp);
240 	kfree(infp);
241 	return ret;
242 }
243 
244 /*
245  * The usual module blurb.
246  */
247 static struct dentry *vxfs_mount(struct file_system_type *fs_type,
248 	int flags, const char *dev_name, void *data)
249 {
250 	return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
251 }
252 
253 static struct file_system_type vxfs_fs_type = {
254 	.owner		= THIS_MODULE,
255 	.name		= "vxfs",
256 	.mount		= vxfs_mount,
257 	.kill_sb	= kill_block_super,
258 	.fs_flags	= FS_REQUIRES_DEV,
259 };
260 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
261 MODULE_ALIAS("vxfs");
262 
263 static int __init
264 vxfs_init(void)
265 {
266 	int rv;
267 
268 	vxfs_inode_cachep = kmem_cache_create("vxfs_inode",
269 			sizeof(struct vxfs_inode_info), 0,
270 			SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
271 	if (!vxfs_inode_cachep)
272 		return -ENOMEM;
273 	rv = register_filesystem(&vxfs_fs_type);
274 	if (rv < 0)
275 		kmem_cache_destroy(vxfs_inode_cachep);
276 	return rv;
277 }
278 
279 static void __exit
280 vxfs_cleanup(void)
281 {
282 	unregister_filesystem(&vxfs_fs_type);
283 	/*
284 	 * Make sure all delayed rcu free inodes are flushed before we
285 	 * destroy cache.
286 	 */
287 	rcu_barrier();
288 	kmem_cache_destroy(vxfs_inode_cachep);
289 }
290 
291 module_init(vxfs_init);
292 module_exit(vxfs_cleanup);
293