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/fs_context.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 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
vxfs_reconfigure(struct fs_context * fc)94 static int vxfs_reconfigure(struct fs_context *fc)
95 {
96 sync_filesystem(fc->root->d_sb);
97 fc->sb_flags |= SB_RDONLY;
98 return 0;
99 }
100
vxfs_alloc_inode(struct super_block * sb)101 static 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
vxfs_free_inode(struct inode * inode)112 static void vxfs_free_inode(struct inode *inode)
113 {
114 kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
115 }
116
117 static 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 };
124
vxfs_try_sb_magic(struct super_block * sbp,struct fs_context * fc,unsigned blk,__fs32 magic)125 static int vxfs_try_sb_magic(struct super_block *sbp, struct fs_context *fc,
126 unsigned blk, __fs32 magic)
127 {
128 struct buffer_head *bp;
129 struct vxfs_sb *rsbp;
130 struct vxfs_sb_info *infp = VXFS_SBI(sbp);
131 int silent = fc->sb_flags & SB_SILENT;
132 int rc = -ENOMEM;
133
134 bp = sb_bread(sbp, blk);
135 do {
136 if (!bp || !buffer_mapped(bp)) {
137 if (!silent) {
138 warnf(fc,
139 "vxfs: unable to read disk superblock at %u",
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 infof(fc,
150 "vxfs: WRONG superblock magic %08x at %u",
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 * @fc: filesytem context
173 *
174 * Description:
175 * We are called on the first mount of a filesystem to read the
176 * superblock into memory and do some basic setup.
177 *
178 * Returns:
179 * The superblock on success, else %NULL.
180 *
181 * Locking:
182 * We are under @sbp->s_lock.
183 */
vxfs_fill_super(struct super_block * sbp,struct fs_context * fc)184 static int vxfs_fill_super(struct super_block *sbp, struct fs_context *fc)
185 {
186 struct vxfs_sb_info *infp;
187 struct vxfs_sb *rsbp;
188 u_long bsize;
189 struct inode *root;
190 int ret = -EINVAL;
191 int silent = fc->sb_flags & SB_SILENT;
192 u32 j;
193
194 sbp->s_flags |= SB_RDONLY;
195
196 infp = kzalloc(sizeof(*infp), GFP_KERNEL);
197 if (!infp) {
198 warnf(fc, "vxfs: unable to allocate incore superblock");
199 return -ENOMEM;
200 }
201
202 bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
203 if (!bsize) {
204 warnf(fc, "vxfs: unable to set blocksize");
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, fc, 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, fc, 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 infof(fc, "vxfs: can't find superblock.");
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 infof(fc, "vxfs: unsupported VxFS version (%d)", 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 warnf(fc, "vxfs: unable to set final block size");
248 goto out;
249 }
250
251 if (vxfs_read_olt(sbp, bsize)) {
252 warnf(fc, "vxfs: unable to read olt");
253 goto out;
254 }
255
256 if (vxfs_read_fshead(sbp)) {
257 warnf(fc, "vxfs: unable to read fshead");
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 warnf(fc, "vxfs: unable to get root dentry.");
269 goto out_free_ilist;
270 }
271
272 return 0;
273
274 out_free_ilist:
275 iput(infp->vsi_fship);
276 iput(infp->vsi_ilist);
277 iput(infp->vsi_stilist);
278 out:
279 brelse(infp->vsi_bp);
280 kfree(infp);
281 return ret;
282 }
283
284 /*
285 * The usual module blurb.
286 */
vxfs_get_tree(struct fs_context * fc)287 static int vxfs_get_tree(struct fs_context *fc)
288 {
289 return get_tree_bdev(fc, vxfs_fill_super);
290 }
291
292 static const struct fs_context_operations vxfs_context_ops = {
293 .get_tree = vxfs_get_tree,
294 .reconfigure = vxfs_reconfigure,
295 };
296
vxfs_init_fs_context(struct fs_context * fc)297 static int vxfs_init_fs_context(struct fs_context *fc)
298 {
299 fc->ops = &vxfs_context_ops;
300
301 return 0;
302 }
303
304 static struct file_system_type vxfs_fs_type = {
305 .owner = THIS_MODULE,
306 .name = "vxfs",
307 .kill_sb = kill_block_super,
308 .fs_flags = FS_REQUIRES_DEV,
309 .init_fs_context = vxfs_init_fs_context,
310 };
311 MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
312 MODULE_ALIAS("vxfs");
313
314 static int __init
vxfs_init(void)315 vxfs_init(void)
316 {
317 int rv;
318
319 vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
320 sizeof(struct vxfs_inode_info), 0,
321 SLAB_RECLAIM_ACCOUNT,
322 offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
323 sizeof_field(struct vxfs_inode_info,
324 vii_immed.vi_immed),
325 NULL);
326 if (!vxfs_inode_cachep)
327 return -ENOMEM;
328 rv = register_filesystem(&vxfs_fs_type);
329 if (rv < 0)
330 kmem_cache_destroy(vxfs_inode_cachep);
331 return rv;
332 }
333
334 static void __exit
vxfs_cleanup(void)335 vxfs_cleanup(void)
336 {
337 unregister_filesystem(&vxfs_fs_type);
338 /*
339 * Make sure all delayed rcu free inodes are flushed before we
340 * destroy cache.
341 */
342 rcu_barrier();
343 kmem_cache_destroy(vxfs_inode_cachep);
344 }
345
346 module_init(vxfs_init);
347 module_exit(vxfs_cleanup);
348