xref: /openbmc/linux/fs/freevxfs/vxfs_super.c (revision 7dd65feb)
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/smp_lock.h>
42 #include <linux/stat.h>
43 #include <linux/vfs.h>
44 #include <linux/mount.h>
45 
46 #include "vxfs.h"
47 #include "vxfs_extern.h"
48 #include "vxfs_dir.h"
49 #include "vxfs_inode.h"
50 
51 
52 MODULE_AUTHOR("Christoph Hellwig");
53 MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
54 MODULE_LICENSE("Dual BSD/GPL");
55 
56 MODULE_ALIAS("vxfs"); /* makes mount -t vxfs autoload the module */
57 
58 
59 static void		vxfs_put_super(struct super_block *);
60 static int		vxfs_statfs(struct dentry *, struct kstatfs *);
61 static int		vxfs_remount(struct super_block *, int *, char *);
62 
63 static const struct super_operations vxfs_super_ops = {
64 	.clear_inode =		vxfs_clear_inode,
65 	.put_super =		vxfs_put_super,
66 	.statfs =		vxfs_statfs,
67 	.remount_fs =		vxfs_remount,
68 };
69 
70 /**
71  * vxfs_put_super - free superblock resources
72  * @sbp:	VFS superblock.
73  *
74  * Description:
75  *   vxfs_put_super frees all resources allocated for @sbp
76  *   after the last instance of the filesystem is unmounted.
77  */
78 
79 static void
80 vxfs_put_super(struct super_block *sbp)
81 {
82 	struct vxfs_sb_info	*infp = VXFS_SBI(sbp);
83 
84 	lock_kernel();
85 
86 	vxfs_put_fake_inode(infp->vsi_fship);
87 	vxfs_put_fake_inode(infp->vsi_ilist);
88 	vxfs_put_fake_inode(infp->vsi_stilist);
89 
90 	brelse(infp->vsi_bp);
91 	kfree(infp);
92 
93 	unlock_kernel();
94 }
95 
96 /**
97  * vxfs_statfs - get filesystem information
98  * @dentry:	VFS dentry to locate superblock
99  * @bufp:	output buffer
100  *
101  * Description:
102  *   vxfs_statfs fills the statfs buffer @bufp with information
103  *   about the filesystem described by @dentry.
104  *
105  * Returns:
106  *   Zero.
107  *
108  * Locking:
109  *   No locks held.
110  *
111  * Notes:
112  *   This is everything but complete...
113  */
114 static int
115 vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
116 {
117 	struct vxfs_sb_info		*infp = VXFS_SBI(dentry->d_sb);
118 
119 	bufp->f_type = VXFS_SUPER_MAGIC;
120 	bufp->f_bsize = dentry->d_sb->s_blocksize;
121 	bufp->f_blocks = infp->vsi_raw->vs_dsize;
122 	bufp->f_bfree = infp->vsi_raw->vs_free;
123 	bufp->f_bavail = 0;
124 	bufp->f_files = 0;
125 	bufp->f_ffree = infp->vsi_raw->vs_ifree;
126 	bufp->f_namelen = VXFS_NAMELEN;
127 
128 	return 0;
129 }
130 
131 static int vxfs_remount(struct super_block *sb, int *flags, char *data)
132 {
133 	*flags |= MS_RDONLY;
134 	return 0;
135 }
136 
137 /**
138  * vxfs_read_super - read superblock into memory and initalize filesystem
139  * @sbp:		VFS superblock (to fill)
140  * @dp:			fs private mount data
141  * @silent:		do not complain loudly when sth is wrong
142  *
143  * Description:
144  *   We are called on the first mount of a filesystem to read the
145  *   superblock into memory and do some basic setup.
146  *
147  * Returns:
148  *   The superblock on success, else %NULL.
149  *
150  * Locking:
151  *   We are under the bkl and @sbp->s_lock.
152  */
153 static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
154 {
155 	struct vxfs_sb_info	*infp;
156 	struct vxfs_sb		*rsbp;
157 	struct buffer_head	*bp = NULL;
158 	u_long			bsize;
159 	struct inode *root;
160 	int ret = -EINVAL;
161 
162 	sbp->s_flags |= MS_RDONLY;
163 
164 	infp = kzalloc(sizeof(*infp), GFP_KERNEL);
165 	if (!infp) {
166 		printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
167 		return -ENOMEM;
168 	}
169 
170 	bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
171 	if (!bsize) {
172 		printk(KERN_WARNING "vxfs: unable to set blocksize\n");
173 		goto out;
174 	}
175 
176 	bp = sb_bread(sbp, 1);
177 	if (!bp || !buffer_mapped(bp)) {
178 		if (!silent) {
179 			printk(KERN_WARNING
180 				"vxfs: unable to read disk superblock\n");
181 		}
182 		goto out;
183 	}
184 
185 	rsbp = (struct vxfs_sb *)bp->b_data;
186 	if (rsbp->vs_magic != VXFS_SUPER_MAGIC) {
187 		if (!silent)
188 			printk(KERN_NOTICE "vxfs: WRONG superblock magic\n");
189 		goto out;
190 	}
191 
192 	if ((rsbp->vs_version < 2 || rsbp->vs_version > 4) && !silent) {
193 		printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n",
194 		       rsbp->vs_version);
195 		goto out;
196 	}
197 
198 #ifdef DIAGNOSTIC
199 	printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", rsbp->vs_version);
200 	printk(KERN_DEBUG "vxfs: blocksize: %d\n", rsbp->vs_bsize);
201 #endif
202 
203 	sbp->s_magic = rsbp->vs_magic;
204 	sbp->s_fs_info = infp;
205 
206 	infp->vsi_raw = rsbp;
207 	infp->vsi_bp = bp;
208 	infp->vsi_oltext = rsbp->vs_oltext[0];
209 	infp->vsi_oltsize = rsbp->vs_oltsize;
210 
211 	if (!sb_set_blocksize(sbp, rsbp->vs_bsize)) {
212 		printk(KERN_WARNING "vxfs: unable to set final block size\n");
213 		goto out;
214 	}
215 
216 	if (vxfs_read_olt(sbp, bsize)) {
217 		printk(KERN_WARNING "vxfs: unable to read olt\n");
218 		goto out;
219 	}
220 
221 	if (vxfs_read_fshead(sbp)) {
222 		printk(KERN_WARNING "vxfs: unable to read fshead\n");
223 		goto out;
224 	}
225 
226 	sbp->s_op = &vxfs_super_ops;
227 	root = vxfs_iget(sbp, VXFS_ROOT_INO);
228 	if (IS_ERR(root)) {
229 		ret = PTR_ERR(root);
230 		goto out;
231 	}
232 	sbp->s_root = d_alloc_root(root);
233 	if (!sbp->s_root) {
234 		iput(root);
235 		printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
236 		goto out_free_ilist;
237 	}
238 
239 	return 0;
240 
241 out_free_ilist:
242 	vxfs_put_fake_inode(infp->vsi_fship);
243 	vxfs_put_fake_inode(infp->vsi_ilist);
244 	vxfs_put_fake_inode(infp->vsi_stilist);
245 out:
246 	brelse(bp);
247 	kfree(infp);
248 	return ret;
249 }
250 
251 /*
252  * The usual module blurb.
253  */
254 static int vxfs_get_sb(struct file_system_type *fs_type,
255 	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
256 {
257 	return get_sb_bdev(fs_type, flags, dev_name, data, vxfs_fill_super,
258 			   mnt);
259 }
260 
261 static struct file_system_type vxfs_fs_type = {
262 	.owner		= THIS_MODULE,
263 	.name		= "vxfs",
264 	.get_sb		= vxfs_get_sb,
265 	.kill_sb	= kill_block_super,
266 	.fs_flags	= FS_REQUIRES_DEV,
267 };
268 
269 static int __init
270 vxfs_init(void)
271 {
272 	int rv;
273 
274 	vxfs_inode_cachep = kmem_cache_create("vxfs_inode",
275 			sizeof(struct vxfs_inode_info), 0,
276 			SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
277 	if (!vxfs_inode_cachep)
278 		return -ENOMEM;
279 	rv = register_filesystem(&vxfs_fs_type);
280 	if (rv < 0)
281 		kmem_cache_destroy(vxfs_inode_cachep);
282 	return rv;
283 }
284 
285 static void __exit
286 vxfs_cleanup(void)
287 {
288 	unregister_filesystem(&vxfs_fs_type);
289 	kmem_cache_destroy(vxfs_inode_cachep);
290 }
291 
292 module_init(vxfs_init);
293 module_exit(vxfs_cleanup);
294