1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2000-2001 Christoph Hellwig.
4 * Copyright (c) 2016 Krzysztof Blaszkowski
5 */
6
7/*
8 * Veritas filesystem driver - superblock related routines.
9 */
10#include <linux/init.h>
11#include <linux/module.h>
12
13#include <linux/blkdev.h>
14#include <linux/fs.h>
15#include <linux/buffer_head.h>
16#include <linux/kernel.h>
17#include <linux/slab.h>
18#include <linux/stat.h>
19#include <linux/vfs.h>
20#include <linux/mount.h>
21
22#include "vxfs.h"
23#include "vxfs_extern.h"
24#include "vxfs_dir.h"
25#include "vxfs_inode.h"
26
27
28MODULE_AUTHOR("Christoph Hellwig, Krzysztof Blaszkowski");
29MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
30MODULE_LICENSE("Dual BSD/GPL");
31
32static struct kmem_cache *vxfs_inode_cachep;
33
34/**
35 * vxfs_put_super - free superblock resources
36 * @sbp:	VFS superblock.
37 *
38 * Description:
39 *   vxfs_put_super frees all resources allocated for @sbp
40 *   after the last instance of the filesystem is unmounted.
41 */
42
43static void
44vxfs_put_super(struct super_block *sbp)
45{
46	struct vxfs_sb_info	*infp = VXFS_SBI(sbp);
47
48	iput(infp->vsi_fship);
49	iput(infp->vsi_ilist);
50	iput(infp->vsi_stilist);
51
52	brelse(infp->vsi_bp);
53	kfree(infp);
54}
55
56/**
57 * vxfs_statfs - get filesystem information
58 * @dentry:	VFS dentry to locate superblock
59 * @bufp:	output buffer
60 *
61 * Description:
62 *   vxfs_statfs fills the statfs buffer @bufp with information
63 *   about the filesystem described by @dentry.
64 *
65 * Returns:
66 *   Zero.
67 *
68 * Locking:
69 *   No locks held.
70 *
71 * Notes:
72 *   This is everything but complete...
73 */
74static int
75vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
76{
77	struct vxfs_sb_info		*infp = VXFS_SBI(dentry->d_sb);
78	struct vxfs_sb *raw_sb = infp->vsi_raw;
79
80	bufp->f_type = VXFS_SUPER_MAGIC;
81	bufp->f_bsize = dentry->d_sb->s_blocksize;
82	bufp->f_blocks = fs32_to_cpu(infp, raw_sb->vs_dsize);
83	bufp->f_bfree = fs32_to_cpu(infp, raw_sb->vs_free);
84	bufp->f_bavail = 0;
85	bufp->f_files = 0;
86	bufp->f_ffree = fs32_to_cpu(infp, raw_sb->vs_ifree);
87	bufp->f_namelen = VXFS_NAMELEN;
88
89	return 0;
90}
91
92static int vxfs_remount(struct super_block *sb, int *flags, char *data)
93{
94	sync_filesystem(sb);
95	*flags |= SB_RDONLY;
96	return 0;
97}
98
99static struct inode *vxfs_alloc_inode(struct super_block *sb)
100{
101	struct vxfs_inode_info *vi;
102
103	vi = alloc_inode_sb(sb, vxfs_inode_cachep, GFP_KERNEL);
104	if (!vi)
105		return NULL;
106	inode_init_once(&vi->vfs_inode);
107	return &vi->vfs_inode;
108}
109
110static void vxfs_free_inode(struct inode *inode)
111{
112	kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
113}
114
115static const struct super_operations vxfs_super_ops = {
116	.alloc_inode		= vxfs_alloc_inode,
117	.free_inode		= vxfs_free_inode,
118	.evict_inode		= vxfs_evict_inode,
119	.put_super		= vxfs_put_super,
120	.statfs			= vxfs_statfs,
121	.remount_fs		= vxfs_remount,
122};
123
124static int vxfs_try_sb_magic(struct super_block *sbp, int silent,
125		unsigned blk, __fs32 magic)
126{
127	struct buffer_head *bp;
128	struct vxfs_sb *rsbp;
129	struct vxfs_sb_info *infp = VXFS_SBI(sbp);
130	int rc = -ENOMEM;
131
132	bp = sb_bread(sbp, blk);
133	do {
134		if (!bp || !buffer_mapped(bp)) {
135			if (!silent) {
136				printk(KERN_WARNING
137					"vxfs: unable to read disk superblock at %u\n",
138					blk);
139			}
140			break;
141		}
142
143		rc = -EINVAL;
144		rsbp = (struct vxfs_sb *)bp->b_data;
145		if (rsbp->vs_magic != magic) {
146			if (!silent)
147				printk(KERN_NOTICE
148					"vxfs: WRONG superblock magic %08x at %u\n",
149					rsbp->vs_magic, blk);
150			break;
151		}
152
153		rc = 0;
154		infp->vsi_raw = rsbp;
155		infp->vsi_bp = bp;
156	} while (0);
157
158	if (rc) {
159		infp->vsi_raw = NULL;
160		infp->vsi_bp = NULL;
161		brelse(bp);
162	}
163
164	return rc;
165}
166
167/**
168 * vxfs_fill_super - read superblock into memory and initialize filesystem
169 * @sbp:		VFS superblock (to fill)
170 * @dp:			fs private mount data
171 * @silent:		do not complain loudly when sth is wrong
172 *
173 * Description:
174 *   We are called on the first mount of a filesystem to read the
175 *   superblock into memory and do some basic setup.
176 *
177 * Returns:
178 *   The superblock on success, else %NULL.
179 *
180 * Locking:
181 *   We are under @sbp->s_lock.
182 */
183static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
184{
185	struct vxfs_sb_info	*infp;
186	struct vxfs_sb		*rsbp;
187	u_long			bsize;
188	struct inode *root;
189	int ret = -EINVAL;
190	u32 j;
191
192	sbp->s_flags |= SB_RDONLY;
193
194	infp = kzalloc(sizeof(*infp), GFP_KERNEL);
195	if (!infp) {
196		printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
197		return -ENOMEM;
198	}
199
200	bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
201	if (!bsize) {
202		printk(KERN_WARNING "vxfs: unable to set blocksize\n");
203		goto out;
204	}
205
206	sbp->s_op = &vxfs_super_ops;
207	sbp->s_fs_info = infp;
208	sbp->s_time_min = 0;
209	sbp->s_time_max = U32_MAX;
210
211	if (!vxfs_try_sb_magic(sbp, silent, 1,
212			(__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
213		/* Unixware, x86 */
214		infp->byte_order = VXFS_BO_LE;
215	} else if (!vxfs_try_sb_magic(sbp, silent, 8,
216			(__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
217		/* HP-UX, parisc */
218		infp->byte_order = VXFS_BO_BE;
219	} else {
220		if (!silent)
221			printk(KERN_NOTICE "vxfs: can't find superblock.\n");
222		goto out;
223	}
224
225	rsbp = infp->vsi_raw;
226	j = fs32_to_cpu(infp, rsbp->vs_version);
227	if ((j < 2 || j > 4) && !silent) {
228		printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n", j);
229		goto out;
230	}
231
232#ifdef DIAGNOSTIC
233	printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
234	printk(KERN_DEBUG "vxfs: blocksize: %d\n",
235		fs32_to_cpu(infp, rsbp->vs_bsize));
236#endif
237
238	sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
239
240	infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
241	infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
242
243	j = fs32_to_cpu(infp, rsbp->vs_bsize);
244	if (!sb_set_blocksize(sbp, j)) {
245		printk(KERN_WARNING "vxfs: unable to set final block size\n");
246		goto out;
247	}
248
249	if (vxfs_read_olt(sbp, bsize)) {
250		printk(KERN_WARNING "vxfs: unable to read olt\n");
251		goto out;
252	}
253
254	if (vxfs_read_fshead(sbp)) {
255		printk(KERN_WARNING "vxfs: unable to read fshead\n");
256		goto out;
257	}
258
259	root = vxfs_iget(sbp, VXFS_ROOT_INO);
260	if (IS_ERR(root)) {
261		ret = PTR_ERR(root);
262		goto out;
263	}
264	sbp->s_root = d_make_root(root);
265	if (!sbp->s_root) {
266		printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
267		goto out_free_ilist;
268	}
269
270	return 0;
271
272out_free_ilist:
273	iput(infp->vsi_fship);
274	iput(infp->vsi_ilist);
275	iput(infp->vsi_stilist);
276out:
277	brelse(infp->vsi_bp);
278	kfree(infp);
279	return ret;
280}
281
282/*
283 * The usual module blurb.
284 */
285static struct dentry *vxfs_mount(struct file_system_type *fs_type,
286	int flags, const char *dev_name, void *data)
287{
288	return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
289}
290
291static struct file_system_type vxfs_fs_type = {
292	.owner		= THIS_MODULE,
293	.name		= "vxfs",
294	.mount		= vxfs_mount,
295	.kill_sb	= kill_block_super,
296	.fs_flags	= FS_REQUIRES_DEV,
297};
298MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
299MODULE_ALIAS("vxfs");
300
301static int __init
302vxfs_init(void)
303{
304	int rv;
305
306	vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
307			sizeof(struct vxfs_inode_info), 0,
308			SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
309			offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
310			sizeof_field(struct vxfs_inode_info,
311				vii_immed.vi_immed),
312			NULL);
313	if (!vxfs_inode_cachep)
314		return -ENOMEM;
315	rv = register_filesystem(&vxfs_fs_type);
316	if (rv < 0)
317		kmem_cache_destroy(vxfs_inode_cachep);
318	return rv;
319}
320
321static void __exit
322vxfs_cleanup(void)
323{
324	unregister_filesystem(&vxfs_fs_type);
325	/*
326	 * Make sure all delayed rcu free inodes are flushed before we
327	 * destroy cache.
328	 */
329	rcu_barrier();
330	kmem_cache_destroy(vxfs_inode_cachep);
331}
332
333module_init(vxfs_init);
334module_exit(vxfs_cleanup);
335