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	u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev);
80
81	bufp->f_type = VXFS_SUPER_MAGIC;
82	bufp->f_bsize = dentry->d_sb->s_blocksize;
83	bufp->f_blocks = fs32_to_cpu(infp, raw_sb->vs_dsize);
84	bufp->f_bfree = fs32_to_cpu(infp, raw_sb->vs_free);
85	bufp->f_bavail = 0;
86	bufp->f_files = 0;
87	bufp->f_ffree = fs32_to_cpu(infp, raw_sb->vs_ifree);
88	bufp->f_fsid = u64_to_fsid(id);
89	bufp->f_namelen = VXFS_NAMELEN;
90
91	return 0;
92}
93
94static int vxfs_remount(struct super_block *sb, int *flags, char *data)
95{
96	sync_filesystem(sb);
97	*flags |= SB_RDONLY;
98	return 0;
99}
100
101static struct inode *vxfs_alloc_inode(struct super_block *sb)
102{
103	struct vxfs_inode_info *vi;
104
105	vi = alloc_inode_sb(sb, vxfs_inode_cachep, GFP_KERNEL);
106	if (!vi)
107		return NULL;
108	inode_init_once(&vi->vfs_inode);
109	return &vi->vfs_inode;
110}
111
112static void vxfs_free_inode(struct inode *inode)
113{
114	kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
115}
116
117static const struct super_operations vxfs_super_ops = {
118	.alloc_inode		= vxfs_alloc_inode,
119	.free_inode		= vxfs_free_inode,
120	.evict_inode		= vxfs_evict_inode,
121	.put_super		= vxfs_put_super,
122	.statfs			= vxfs_statfs,
123	.remount_fs		= vxfs_remount,
124};
125
126static int vxfs_try_sb_magic(struct super_block *sbp, int silent,
127		unsigned blk, __fs32 magic)
128{
129	struct buffer_head *bp;
130	struct vxfs_sb *rsbp;
131	struct vxfs_sb_info *infp = VXFS_SBI(sbp);
132	int rc = -ENOMEM;
133
134	bp = sb_bread(sbp, blk);
135	do {
136		if (!bp || !buffer_mapped(bp)) {
137			if (!silent) {
138				printk(KERN_WARNING
139					"vxfs: unable to read disk superblock at %u\n",
140					blk);
141			}
142			break;
143		}
144
145		rc = -EINVAL;
146		rsbp = (struct vxfs_sb *)bp->b_data;
147		if (rsbp->vs_magic != magic) {
148			if (!silent)
149				printk(KERN_NOTICE
150					"vxfs: WRONG superblock magic %08x at %u\n",
151					rsbp->vs_magic, blk);
152			break;
153		}
154
155		rc = 0;
156		infp->vsi_raw = rsbp;
157		infp->vsi_bp = bp;
158	} while (0);
159
160	if (rc) {
161		infp->vsi_raw = NULL;
162		infp->vsi_bp = NULL;
163		brelse(bp);
164	}
165
166	return rc;
167}
168
169/**
170 * vxfs_fill_super - read superblock into memory and initialize filesystem
171 * @sbp:		VFS superblock (to fill)
172 * @dp:			fs private mount data
173 * @silent:		do not complain loudly when sth is wrong
174 *
175 * Description:
176 *   We are called on the first mount of a filesystem to read the
177 *   superblock into memory and do some basic setup.
178 *
179 * Returns:
180 *   The superblock on success, else %NULL.
181 *
182 * Locking:
183 *   We are under @sbp->s_lock.
184 */
185static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
186{
187	struct vxfs_sb_info	*infp;
188	struct vxfs_sb		*rsbp;
189	u_long			bsize;
190	struct inode *root;
191	int ret = -EINVAL;
192	u32 j;
193
194	sbp->s_flags |= SB_RDONLY;
195
196	infp = kzalloc(sizeof(*infp), GFP_KERNEL);
197	if (!infp) {
198		printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
199		return -ENOMEM;
200	}
201
202	bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
203	if (!bsize) {
204		printk(KERN_WARNING "vxfs: unable to set blocksize\n");
205		goto out;
206	}
207
208	sbp->s_op = &vxfs_super_ops;
209	sbp->s_fs_info = infp;
210	sbp->s_time_min = 0;
211	sbp->s_time_max = U32_MAX;
212
213	if (!vxfs_try_sb_magic(sbp, silent, 1,
214			(__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
215		/* Unixware, x86 */
216		infp->byte_order = VXFS_BO_LE;
217	} else if (!vxfs_try_sb_magic(sbp, silent, 8,
218			(__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
219		/* HP-UX, parisc */
220		infp->byte_order = VXFS_BO_BE;
221	} else {
222		if (!silent)
223			printk(KERN_NOTICE "vxfs: can't find superblock.\n");
224		goto out;
225	}
226
227	rsbp = infp->vsi_raw;
228	j = fs32_to_cpu(infp, rsbp->vs_version);
229	if ((j < 2 || j > 4) && !silent) {
230		printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n", j);
231		goto out;
232	}
233
234#ifdef DIAGNOSTIC
235	printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
236	printk(KERN_DEBUG "vxfs: blocksize: %d\n",
237		fs32_to_cpu(infp, rsbp->vs_bsize));
238#endif
239
240	sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
241
242	infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
243	infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
244
245	j = fs32_to_cpu(infp, rsbp->vs_bsize);
246	if (!sb_set_blocksize(sbp, j)) {
247		printk(KERN_WARNING "vxfs: unable to set final block size\n");
248		goto out;
249	}
250
251	if (vxfs_read_olt(sbp, bsize)) {
252		printk(KERN_WARNING "vxfs: unable to read olt\n");
253		goto out;
254	}
255
256	if (vxfs_read_fshead(sbp)) {
257		printk(KERN_WARNING "vxfs: unable to read fshead\n");
258		goto out;
259	}
260
261	root = vxfs_iget(sbp, VXFS_ROOT_INO);
262	if (IS_ERR(root)) {
263		ret = PTR_ERR(root);
264		goto out;
265	}
266	sbp->s_root = d_make_root(root);
267	if (!sbp->s_root) {
268		printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
269		goto out_free_ilist;
270	}
271
272	return 0;
273
274out_free_ilist:
275	iput(infp->vsi_fship);
276	iput(infp->vsi_ilist);
277	iput(infp->vsi_stilist);
278out:
279	brelse(infp->vsi_bp);
280	kfree(infp);
281	return ret;
282}
283
284/*
285 * The usual module blurb.
286 */
287static struct dentry *vxfs_mount(struct file_system_type *fs_type,
288	int flags, const char *dev_name, void *data)
289{
290	return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
291}
292
293static struct file_system_type vxfs_fs_type = {
294	.owner		= THIS_MODULE,
295	.name		= "vxfs",
296	.mount		= vxfs_mount,
297	.kill_sb	= kill_block_super,
298	.fs_flags	= FS_REQUIRES_DEV,
299};
300MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
301MODULE_ALIAS("vxfs");
302
303static int __init
304vxfs_init(void)
305{
306	int rv;
307
308	vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
309			sizeof(struct vxfs_inode_info), 0,
310			SLAB_RECLAIM_ACCOUNT,
311			offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
312			sizeof_field(struct vxfs_inode_info,
313				vii_immed.vi_immed),
314			NULL);
315	if (!vxfs_inode_cachep)
316		return -ENOMEM;
317	rv = register_filesystem(&vxfs_fs_type);
318	if (rv < 0)
319		kmem_cache_destroy(vxfs_inode_cachep);
320	return rv;
321}
322
323static void __exit
324vxfs_cleanup(void)
325{
326	unregister_filesystem(&vxfs_fs_type);
327	/*
328	 * Make sure all delayed rcu free inodes are flushed before we
329	 * destroy cache.
330	 */
331	rcu_barrier();
332	kmem_cache_destroy(vxfs_inode_cachep);
333}
334
335module_init(vxfs_init);
336module_exit(vxfs_cleanup);
337