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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 MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
56 
57 static struct kmem_cache *vxfs_inode_cachep;
58 
59 /**
60  * vxfs_put_super - free superblock resources
61  * @sbp:	VFS superblock.
62  *
63  * Description:
64  *   vxfs_put_super frees all resources allocated for @sbp
65  *   after the last instance of the filesystem is unmounted.
66  */
67 
68 static void
vxfs_put_super(struct super_block * sbp)69 vxfs_put_super(struct super_block *sbp)
70 {
71 	struct vxfs_sb_info	*infp = VXFS_SBI(sbp);
72 
73 	iput(infp->vsi_fship);
74 	iput(infp->vsi_ilist);
75 	iput(infp->vsi_stilist);
76 
77 	brelse(infp->vsi_bp);
78 	kfree(infp);
79 }
80 
81 /**
82  * vxfs_statfs - get filesystem information
83  * @dentry:	VFS dentry to locate superblock
84  * @bufp:	output buffer
85  *
86  * Description:
87  *   vxfs_statfs fills the statfs buffer @bufp with information
88  *   about the filesystem described by @dentry.
89  *
90  * Returns:
91  *   Zero.
92  *
93  * Locking:
94  *   No locks held.
95  *
96  * Notes:
97  *   This is everything but complete...
98  */
99 static int
vxfs_statfs(struct dentry * dentry,struct kstatfs * bufp)100 vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
101 {
102 	struct vxfs_sb_info		*infp = VXFS_SBI(dentry->d_sb);
103 	struct vxfs_sb *raw_sb = infp->vsi_raw;
104 
105 	bufp->f_type = VXFS_SUPER_MAGIC;
106 	bufp->f_bsize = dentry->d_sb->s_blocksize;
107 	bufp->f_blocks = fs32_to_cpu(infp, raw_sb->vs_dsize);
108 	bufp->f_bfree = fs32_to_cpu(infp, raw_sb->vs_free);
109 	bufp->f_bavail = 0;
110 	bufp->f_files = 0;
111 	bufp->f_ffree = fs32_to_cpu(infp, raw_sb->vs_ifree);
112 	bufp->f_namelen = VXFS_NAMELEN;
113 
114 	return 0;
115 }
116 
vxfs_remount(struct super_block * sb,int * flags,char * data)117 static int vxfs_remount(struct super_block *sb, int *flags, char *data)
118 {
119 	sync_filesystem(sb);
120 	*flags |= SB_RDONLY;
121 	return 0;
122 }
123 
vxfs_alloc_inode(struct super_block * sb)124 static struct inode *vxfs_alloc_inode(struct super_block *sb)
125 {
126 	struct vxfs_inode_info *vi;
127 
128 	vi = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL);
129 	if (!vi)
130 		return NULL;
131 	inode_init_once(&vi->vfs_inode);
132 	return &vi->vfs_inode;
133 }
134 
vxfs_free_inode(struct inode * inode)135 static void vxfs_free_inode(struct inode *inode)
136 {
137 	kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
138 }
139 
140 static const struct super_operations vxfs_super_ops = {
141 	.alloc_inode		= vxfs_alloc_inode,
142 	.free_inode		= vxfs_free_inode,
143 	.evict_inode		= vxfs_evict_inode,
144 	.put_super		= vxfs_put_super,
145 	.statfs			= vxfs_statfs,
146 	.remount_fs		= vxfs_remount,
147 };
148 
vxfs_try_sb_magic(struct super_block * sbp,int silent,unsigned blk,__fs32 magic)149 static int vxfs_try_sb_magic(struct super_block *sbp, int silent,
150 		unsigned blk, __fs32 magic)
151 {
152 	struct buffer_head *bp;
153 	struct vxfs_sb *rsbp;
154 	struct vxfs_sb_info *infp = VXFS_SBI(sbp);
155 	int rc = -ENOMEM;
156 
157 	bp = sb_bread(sbp, blk);
158 	do {
159 		if (!bp || !buffer_mapped(bp)) {
160 			if (!silent) {
161 				printk(KERN_WARNING
162 					"vxfs: unable to read disk superblock at %u\n",
163 					blk);
164 			}
165 			break;
166 		}
167 
168 		rc = -EINVAL;
169 		rsbp = (struct vxfs_sb *)bp->b_data;
170 		if (rsbp->vs_magic != magic) {
171 			if (!silent)
172 				printk(KERN_NOTICE
173 					"vxfs: WRONG superblock magic %08x at %u\n",
174 					rsbp->vs_magic, blk);
175 			break;
176 		}
177 
178 		rc = 0;
179 		infp->vsi_raw = rsbp;
180 		infp->vsi_bp = bp;
181 	} while (0);
182 
183 	if (rc) {
184 		infp->vsi_raw = NULL;
185 		infp->vsi_bp = NULL;
186 		brelse(bp);
187 	}
188 
189 	return rc;
190 }
191 
192 /**
193  * vxfs_read_super - read superblock into memory and initialize filesystem
194  * @sbp:		VFS superblock (to fill)
195  * @dp:			fs private mount data
196  * @silent:		do not complain loudly when sth is wrong
197  *
198  * Description:
199  *   We are called on the first mount of a filesystem to read the
200  *   superblock into memory and do some basic setup.
201  *
202  * Returns:
203  *   The superblock on success, else %NULL.
204  *
205  * Locking:
206  *   We are under @sbp->s_lock.
207  */
vxfs_fill_super(struct super_block * sbp,void * dp,int silent)208 static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
209 {
210 	struct vxfs_sb_info	*infp;
211 	struct vxfs_sb		*rsbp;
212 	u_long			bsize;
213 	struct inode *root;
214 	int ret = -EINVAL;
215 	u32 j;
216 
217 	sbp->s_flags |= SB_RDONLY;
218 
219 	infp = kzalloc(sizeof(*infp), GFP_KERNEL);
220 	if (!infp) {
221 		printk(KERN_WARNING "vxfs: unable to allocate incore superblock\n");
222 		return -ENOMEM;
223 	}
224 
225 	bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
226 	if (!bsize) {
227 		printk(KERN_WARNING "vxfs: unable to set blocksize\n");
228 		goto out;
229 	}
230 
231 	sbp->s_op = &vxfs_super_ops;
232 	sbp->s_fs_info = infp;
233 	sbp->s_time_min = 0;
234 	sbp->s_time_max = U32_MAX;
235 
236 	if (!vxfs_try_sb_magic(sbp, silent, 1,
237 			(__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
238 		/* Unixware, x86 */
239 		infp->byte_order = VXFS_BO_LE;
240 	} else if (!vxfs_try_sb_magic(sbp, silent, 8,
241 			(__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
242 		/* HP-UX, parisc */
243 		infp->byte_order = VXFS_BO_BE;
244 	} else {
245 		if (!silent)
246 			printk(KERN_NOTICE "vxfs: can't find superblock.\n");
247 		goto out;
248 	}
249 
250 	rsbp = infp->vsi_raw;
251 	j = fs32_to_cpu(infp, rsbp->vs_version);
252 	if ((j < 2 || j > 4) && !silent) {
253 		printk(KERN_NOTICE "vxfs: unsupported VxFS version (%d)\n", j);
254 		goto out;
255 	}
256 
257 #ifdef DIAGNOSTIC
258 	printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
259 	printk(KERN_DEBUG "vxfs: blocksize: %d\n",
260 		fs32_to_cpu(infp, rsbp->vs_bsize));
261 #endif
262 
263 	sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
264 
265 	infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
266 	infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
267 
268 	j = fs32_to_cpu(infp, rsbp->vs_bsize);
269 	if (!sb_set_blocksize(sbp, j)) {
270 		printk(KERN_WARNING "vxfs: unable to set final block size\n");
271 		goto out;
272 	}
273 
274 	if (vxfs_read_olt(sbp, bsize)) {
275 		printk(KERN_WARNING "vxfs: unable to read olt\n");
276 		goto out;
277 	}
278 
279 	if (vxfs_read_fshead(sbp)) {
280 		printk(KERN_WARNING "vxfs: unable to read fshead\n");
281 		goto out;
282 	}
283 
284 	root = vxfs_iget(sbp, VXFS_ROOT_INO);
285 	if (IS_ERR(root)) {
286 		ret = PTR_ERR(root);
287 		goto out;
288 	}
289 	sbp->s_root = d_make_root(root);
290 	if (!sbp->s_root) {
291 		printk(KERN_WARNING "vxfs: unable to get root dentry.\n");
292 		goto out_free_ilist;
293 	}
294 
295 	return 0;
296 
297 out_free_ilist:
298 	iput(infp->vsi_fship);
299 	iput(infp->vsi_ilist);
300 	iput(infp->vsi_stilist);
301 out:
302 	brelse(infp->vsi_bp);
303 	kfree(infp);
304 	return ret;
305 }
306 
307 /*
308  * The usual module blurb.
309  */
vxfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)310 static struct dentry *vxfs_mount(struct file_system_type *fs_type,
311 	int flags, const char *dev_name, void *data)
312 {
313 	return mount_bdev(fs_type, flags, dev_name, data, vxfs_fill_super);
314 }
315 
316 static struct file_system_type vxfs_fs_type = {
317 	.owner		= THIS_MODULE,
318 	.name		= "vxfs",
319 	.mount		= vxfs_mount,
320 	.kill_sb	= kill_block_super,
321 	.fs_flags	= FS_REQUIRES_DEV,
322 };
323 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
324 MODULE_ALIAS("vxfs");
325 
326 static int __init
vxfs_init(void)327 vxfs_init(void)
328 {
329 	int rv;
330 
331 	vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
332 			sizeof(struct vxfs_inode_info), 0,
333 			SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
334 			offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
335 			sizeof_field(struct vxfs_inode_info,
336 				vii_immed.vi_immed),
337 			NULL);
338 	if (!vxfs_inode_cachep)
339 		return -ENOMEM;
340 	rv = register_filesystem(&vxfs_fs_type);
341 	if (rv < 0)
342 		kmem_cache_destroy(vxfs_inode_cachep);
343 	return rv;
344 }
345 
346 static void __exit
vxfs_cleanup(void)347 vxfs_cleanup(void)
348 {
349 	unregister_filesystem(&vxfs_fs_type);
350 	/*
351 	 * Make sure all delayed rcu free inodes are flushed before we
352 	 * destroy cache.
353 	 */
354 	rcu_barrier();
355 	kmem_cache_destroy(vxfs_inode_cachep);
356 }
357 
358 module_init(vxfs_init);
359 module_exit(vxfs_cleanup);
360