c3b82f716f9a7c7a13e3b90baf38f54b65ef7c8c
[releases.git] / vxfs_super.c
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
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
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
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
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
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
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_read_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  */
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  */
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
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
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);