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