xref: /linux/fs/freevxfs/vxfs_super.c (revision 52338415)
1 /*
2  * Copyright (c) 2000-2001 Christoph Hellwig.
3  * Copyright (c) 2016 Krzysztof Blaszkowski
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions, and the following disclaimer,
11  *    without modification.
12  * 2. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * Alternatively, this software may be distributed under the terms of the
16  * GNU General Public License ("GPL").
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
22  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  * Veritas filesystem driver - superblock related routines.
33  */
34 #include <linux/init.h>
35 #include <linux/module.h>
36 
37 #include <linux/blkdev.h>
38 #include <linux/fs.h>
39 #include <linux/buffer_head.h>
40 #include <linux/kernel.h>
41 #include <linux/slab.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, Krzysztof Blaszkowski");
53 MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
54 MODULE_LICENSE("Dual BSD/GPL");
55 
56 static struct kmem_cache *vxfs_inode_cachep;
57 
58 /**
59  * vxfs_put_super - free superblock resources
60  * @sbp:	VFS superblock.
61  *
62  * Description:
63  *   vxfs_put_super frees all resources allocated for @sbp
64  *   after the last instance of the filesystem is unmounted.
65  */
66 
67 static void
68 vxfs_put_super(struct super_block *sbp)
69 {
70 	struct vxfs_sb_info	*infp = VXFS_SBI(sbp);
71 
72 	iput(infp->vsi_fship);
73 	iput(infp->vsi_ilist);
74 	iput(infp->vsi_stilist);
75 
76 	brelse(infp->vsi_bp);
77 	kfree(infp);
78 }
79 
80 /**
81  * vxfs_statfs - get filesystem information
82  * @dentry:	VFS dentry to locate superblock
83  * @bufp:	output buffer
84  *
85  * Description:
86  *   vxfs_statfs fills the statfs buffer @bufp with information
87  *   about the filesystem described by @dentry.
88  *
89  * Returns:
90  *   Zero.
91  *
92  * Locking:
93  *   No locks held.
94  *
95  * Notes:
96  *   This is everything but complete...
97  */
98 static int
99 vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
100 {
101 	struct vxfs_sb_info		*infp = VXFS_SBI(dentry->d_sb);
102 	struct vxfs_sb *raw_sb = infp->vsi_raw;
103 
104 	bufp->f_type = VXFS_SUPER_MAGIC;
105 	bufp->f_bsize = dentry->d_sb->s_blocksize;
106 	bufp->f_blocks = fs32_to_cpu(infp, raw_sb->vs_dsize);
107 	bufp->f_bfree = fs32_to_cpu(infp, raw_sb->vs_free);
108 	bufp->f_bavail = 0;
109 	bufp->f_files = 0;
110 	bufp->f_ffree = fs32_to_cpu(infp, raw_sb->vs_ifree);
111 	bufp->f_namelen = VXFS_NAMELEN;
112 
113 	return 0;
114 }
115 
116 static int vxfs_remount(struct super_block *sb, int *flags, char *data)
117 {
118 	sync_filesystem(sb);
119 	*flags |= SB_RDONLY;
120 	return 0;
121 }
122 
123 static struct inode *vxfs_alloc_inode(struct super_block *sb)
124 {
125 	struct vxfs_inode_info *vi;
126 
127 	vi = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL);
128 	if (!vi)
129 		return NULL;
130 	inode_init_once(&vi->vfs_inode);
131 	return &vi->vfs_inode;
132 }
133 
134 static void vxfs_free_inode(struct inode *inode)
135 {
136 	kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
137 }
138 
139 static const struct super_operations vxfs_super_ops = {
140 	.alloc_inode		= vxfs_alloc_inode,
141 	.free_inode		= vxfs_free_inode,
142 	.evict_inode		= vxfs_evict_inode,
143 	.put_super		= vxfs_put_super,
144 	.statfs			= vxfs_statfs,
145 	.remount_fs		= vxfs_remount,
146 };
147 
148 static int vxfs_try_sb_magic(struct super_block *sbp, int silent,
149 		unsigned blk, __fs32 magic)
150 {
151 	struct buffer_head *bp;
152 	struct vxfs_sb *rsbp;
153 	struct vxfs_sb_info *infp = VXFS_SBI(sbp);
154 	int rc = -ENOMEM;
155 
156 	bp = sb_bread(sbp, blk);
157 	do {
158 		if (!bp || !buffer_mapped(bp)) {
159 			if (!silent) {
160 				printk(KERN_WARNING
161 					"vxfs: unable to read disk superblock at %u\n",
162 					blk);
163 			}
164 			break;
165 		}
166 
167 		rc = -EINVAL;
168 		rsbp = (struct vxfs_sb *)bp->b_data;
169 		if (rsbp->vs_magic != magic) {
170 			if (!silent)
171 				printk(KERN_NOTICE
172 					"vxfs: WRONG superblock magic %08x at %u\n",
173 					rsbp->vs_magic, blk);
174 			break;
175 		}
176 
177 		rc = 0;
178 		infp->vsi_raw = rsbp;
179 		infp->vsi_bp = bp;
180 	} while (0);
181 
182 	if (rc) {
183 		infp->vsi_raw = NULL;
184 		infp->vsi_bp = NULL;
185 		brelse(bp);
186 	}
187 
188 	return rc;
189 }
190 
191 /**
192  * vxfs_read_super - read superblock into memory and initialize filesystem
193  * @sbp:		VFS superblock (to fill)
194  * @dp:			fs private mount data
195  * @silent:		do not complain loudly when sth is wrong
196  *
197  * Description:
198  *   We are called on the first mount of a filesystem to read the
199  *   superblock into memory and do some basic setup.
200  *
201  * Returns:
202  *   The superblock on success, else %NULL.
203  *
204  * Locking:
205  *   We are under @sbp->s_lock.
206  */
207 static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
208 {
209 	struct vxfs_sb_info	*infp;
210 	struct vxfs_sb		*rsbp;
211 	u_long			bsize;
212 	struct inode *root;
213 	int ret = -EINVAL;
214 	u32 j;
215 
216 	sbp->s_flags |= SB_RDONLY;
217 
218 	infp = kzalloc(sizeof(*infp), GFP_KERNEL);
219 	if (!infp) {
220 		printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
221 		return -ENOMEM;
222 	}
223 
224 	bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
225 	if (!bsize) {
226 		printk(KERN_WARNING "vxfs: unable to set blocksize\n");
227 		goto out;
228 	}
229 
230 	sbp->s_op = &vxfs_super_ops;
231 	sbp->s_fs_info = infp;
232 	sbp->s_time_min = 0;
233 	sbp->s_time_max = U32_MAX;
234 
235 	if (!vxfs_try_sb_magic(sbp, silent, 1,
236 			(__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
237 		/* Unixware, x86 */
238 		infp->byte_order = VXFS_BO_LE;
239 	} else if (!vxfs_try_sb_magic(sbp, silent, 8,
240 			(__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
241 		/* HP-UX, parisc */
242 		infp->byte_order = VXFS_BO_BE;
243 	} else {
244 		if (!silent)
245 			printk(KERN_NOTICE "vxfs: can't find superblock.\n");
246 		goto out;
247 	}
248 
249 	rsbp = infp->vsi_raw;
250 	j = fs32_to_cpu(infp, rsbp->vs_version);
251 	if ((j < 2 || j > 4) && !silent) {
252 		printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n", j);
253 		goto out;
254 	}
255 
256 #ifdef DIAGNOSTIC
257 	printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
258 	printk(KERN_DEBUG "vxfs: blocksize: %d\n",
259 		fs32_to_cpu(infp, rsbp->vs_bsize));
260 #endif
261 
262 	sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
263 
264 	infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
265 	infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
266 
267 	j = fs32_to_cpu(infp, rsbp->vs_bsize);
268 	if (!sb_set_blocksize(sbp, j)) {
269 		printk(KERN_WARNING "vxfs: unable to set final block size\n");
270 		goto out;
271 	}
272 
273 	if (vxfs_read_olt(sbp, bsize)) {
274 		printk(KERN_WARNING "vxfs: unable to read olt\n");
275 		goto out;
276 	}
277 
278 	if (vxfs_read_fshead(sbp)) {
279 		printk(KERN_WARNING "vxfs: unable to read fshead\n");
280 		goto out;
281 	}
282 
283 	root = vxfs_iget(sbp, VXFS_ROOT_INO);
284 	if (IS_ERR(root)) {
285 		ret = PTR_ERR(root);
286 		goto out;
287 	}
288 	sbp->s_root = d_make_root(root);
289 	if (!sbp->s_root) {
290 		printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
291 		goto out_free_ilist;
292 	}
293 
294 	return 0;
295 
296 out_free_ilist:
297 	iput(infp->vsi_fship);
298 	iput(infp->vsi_ilist);
299 	iput(infp->vsi_stilist);
300 out:
301 	brelse(infp->vsi_bp);
302 	kfree(infp);
303 	return ret;
304 }
305 
306 /*
307  * The usual module blurb.
308  */
309 static struct dentry *vxfs_mount(struct file_system_type *fs_type,
310 	int flags, const char *dev_name, void *data)
311 {
312 	return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
313 }
314 
315 static struct file_system_type vxfs_fs_type = {
316 	.owner		= THIS_MODULE,
317 	.name		= "vxfs",
318 	.mount		= vxfs_mount,
319 	.kill_sb	= kill_block_super,
320 	.fs_flags	= FS_REQUIRES_DEV,
321 };
322 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
323 MODULE_ALIAS("vxfs");
324 
325 static int __init
326 vxfs_init(void)
327 {
328 	int rv;
329 
330 	vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
331 			sizeof(struct vxfs_inode_info), 0,
332 			SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
333 			offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
334 			sizeof_field(struct vxfs_inode_info,
335 				vii_immed.vi_immed),
336 			NULL);
337 	if (!vxfs_inode_cachep)
338 		return -ENOMEM;
339 	rv = register_filesystem(&vxfs_fs_type);
340 	if (rv < 0)
341 		kmem_cache_destroy(vxfs_inode_cachep);
342 	return rv;
343 }
344 
345 static void __exit
346 vxfs_cleanup(void)
347 {
348 	unregister_filesystem(&vxfs_fs_type);
349 	/*
350 	 * Make sure all delayed rcu free inodes are flushed before we
351 	 * destroy cache.
352 	 */
353 	rcu_barrier();
354 	kmem_cache_destroy(vxfs_inode_cachep);
355 }
356 
357 module_init(vxfs_init);
358 module_exit(vxfs_cleanup);
359