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
28 MODULE_AUTHOR("Christoph Hellwig, Krzysztof Blaszkowski");
29 MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
30 MODULE_LICENSE("Dual BSD/GPL");
31
32 static 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
43 static void
vxfs_put_super(struct super_block * sbp)44 vxfs_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 */
74 static int
vxfs_statfs(struct dentry * dentry,struct kstatfs * bufp)75 vxfs_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
vxfs_remount(struct super_block * sb,int * flags,char * data)92 static 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
vxfs_alloc_inode(struct super_block * sb)99 static 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
vxfs_free_inode(struct inode * inode)110 static void vxfs_free_inode(struct inode *inode)
111 {
112 kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
113 }
114
115 static 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
vxfs_try_sb_magic(struct super_block * sbp,int silent,unsigned blk,__fs32 magic)124 static 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 */
vxfs_fill_super(struct super_block * sbp,void * dp,int silent)183 static 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
272 out_free_ilist:
273 iput(infp->vsi_fship);
274 iput(infp->vsi_ilist);
275 iput(infp->vsi_stilist);
276 out:
277 brelse(infp->vsi_bp);
278 kfree(infp);
279 return ret;
280 }
281
282 /*
283 * The usual module blurb.
284 */
vxfs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)285 static 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
291 static 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 };
298 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
299 MODULE_ALIAS("vxfs");
300
301 static int __init
vxfs_init(void)302 vxfs_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
321 static void __exit
vxfs_cleanup(void)322 vxfs_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
333 module_init(vxfs_init);
334 module_exit(vxfs_cleanup);
335