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
52MODULE_AUTHOR("Christoph Hellwig, Krzysztof Blaszkowski");
53MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
54MODULE_LICENSE("Dual BSD/GPL");
55
56static 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
67static void
68vxfs_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 */
98static int
99vxfs_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
116static 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
123static 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
134static void vxfs_free_inode(struct inode *inode)
135{
136	kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
137}
138
139static 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
148static 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 */
207static 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
296out_free_ilist:
297	iput(infp->vsi_fship);
298	iput(infp->vsi_ilist);
299	iput(infp->vsi_stilist);
300out:
301	brelse(infp->vsi_bp);
302	kfree(infp);
303	return ret;
304}
305
306/*
307 * The usual module blurb.
308 */
309static 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
315static 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};
322MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
323MODULE_ALIAS("vxfs");
324
325static int __init
326vxfs_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
345static void __exit
346vxfs_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
357module_init(vxfs_init);
358module_exit(vxfs_cleanup);
359