exportfs: make ->encode_fh() a mandatory method for NFS export
[linux-block.git] / fs / efs / super.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4
LT
2/*
3 * super.c
4 *
5 * Copyright (c) 1999 Al Smith
6 *
7 * Portions derived from work (c) 1995,1996 Christian Vogelgsang.
8 */
9
10#include <linux/init.h>
11#include <linux/module.h>
a5694255 12#include <linux/exportfs.h>
1da177e4
LT
13#include <linux/slab.h>
14#include <linux/buffer_head.h>
15#include <linux/vfs.h>
621c1f42 16#include <linux/blkdev.h>
1da177e4 17
45254b4f
CH
18#include "efs.h"
19#include <linux/efs_vh.h>
20#include <linux/efs_fs_sb.h>
21
726c3342 22static int efs_statfs(struct dentry *dentry, struct kstatfs *buf);
1da177e4
LT
23static int efs_fill_super(struct super_block *s, void *d, int silent);
24
152a0836
AV
25static struct dentry *efs_mount(struct file_system_type *fs_type,
26 int flags, const char *dev_name, void *data)
1da177e4 27{
152a0836 28 return mount_bdev(fs_type, flags, dev_name, data, efs_fill_super);
1da177e4
LT
29}
30
5a9ed6f5
AV
31static void efs_kill_sb(struct super_block *s)
32{
33 struct efs_sb_info *sbi = SUPER_INFO(s);
34 kill_block_super(s);
35 kfree(sbi);
36}
37
1da177e4
LT
38static struct file_system_type efs_fs_type = {
39 .owner = THIS_MODULE,
40 .name = "efs",
152a0836 41 .mount = efs_mount,
5a9ed6f5 42 .kill_sb = efs_kill_sb,
1da177e4
LT
43 .fs_flags = FS_REQUIRES_DEV,
44};
7f78e035 45MODULE_ALIAS_FS("efs");
1da177e4
LT
46
47static struct pt_types sgi_pt_types[] = {
48 {0x00, "SGI vh"},
49 {0x01, "SGI trkrepl"},
50 {0x02, "SGI secrepl"},
51 {0x03, "SGI raw"},
52 {0x04, "SGI bsd"},
53 {SGI_SYSV, "SGI sysv"},
54 {0x06, "SGI vol"},
55 {SGI_EFS, "SGI efs"},
56 {0x08, "SGI lv"},
57 {0x09, "SGI rlv"},
58 {0x0A, "SGI xfs"},
59 {0x0B, "SGI xfslog"},
60 {0x0C, "SGI xlv"},
61 {0x82, "Linux swap"},
62 {0x83, "Linux native"},
63 {0, NULL}
64};
65
66
e18b890b 67static struct kmem_cache * efs_inode_cachep;
1da177e4
LT
68
69static struct inode *efs_alloc_inode(struct super_block *sb)
70{
71 struct efs_inode_info *ei;
fd60b288 72 ei = alloc_inode_sb(sb, efs_inode_cachep, GFP_KERNEL);
1da177e4
LT
73 if (!ei)
74 return NULL;
75 return &ei->vfs_inode;
76}
77
f415c511 78static void efs_free_inode(struct inode *inode)
1da177e4
LT
79{
80 kmem_cache_free(efs_inode_cachep, INODE_INFO(inode));
81}
82
51cc5068 83static void init_once(void *foo)
1da177e4
LT
84{
85 struct efs_inode_info *ei = (struct efs_inode_info *) foo;
86
a35afb83 87 inode_init_once(&ei->vfs_inode);
1da177e4 88}
20c2df83 89
7a42d4b6 90static int __init init_inodecache(void)
1da177e4
LT
91{
92 efs_inode_cachep = kmem_cache_create("efs_inode_cache",
5d097056
VD
93 sizeof(struct efs_inode_info), 0,
94 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
95 SLAB_ACCOUNT, init_once);
1da177e4
LT
96 if (efs_inode_cachep == NULL)
97 return -ENOMEM;
98 return 0;
99}
100
101static void destroy_inodecache(void)
102{
8c0a8537
KS
103 /*
104 * Make sure all delayed rcu free inodes are flushed before we
105 * destroy cache.
106 */
107 rcu_barrier();
1a1d92c1 108 kmem_cache_destroy(efs_inode_cachep);
1da177e4
LT
109}
110
1da177e4
LT
111static int efs_remount(struct super_block *sb, int *flags, char *data)
112{
02b9984d 113 sync_filesystem(sb);
1751e8a6 114 *flags |= SB_RDONLY;
1da177e4
LT
115 return 0;
116}
117
ee9b6d61 118static const struct super_operations efs_superblock_operations = {
1da177e4 119 .alloc_inode = efs_alloc_inode,
f415c511 120 .free_inode = efs_free_inode,
1da177e4
LT
121 .statfs = efs_statfs,
122 .remount_fs = efs_remount,
123};
124
39655164 125static const struct export_operations efs_export_ops = {
e21fc203 126 .encode_fh = generic_encode_ino32_fh,
05da0804
CH
127 .fh_to_dentry = efs_fh_to_dentry,
128 .fh_to_parent = efs_fh_to_parent,
1da177e4
LT
129 .get_parent = efs_get_parent,
130};
131
132static int __init init_efs_fs(void) {
133 int err;
f403d1db 134 pr_info(EFS_VERSION" - http://aeschi.ch.eu.org/efs/\n");
1da177e4
LT
135 err = init_inodecache();
136 if (err)
137 goto out1;
138 err = register_filesystem(&efs_fs_type);
139 if (err)
140 goto out;
141 return 0;
142out:
143 destroy_inodecache();
144out1:
145 return err;
146}
147
148static void __exit exit_efs_fs(void) {
149 unregister_filesystem(&efs_fs_type);
150 destroy_inodecache();
151}
152
153module_init(init_efs_fs)
154module_exit(exit_efs_fs)
155
156static efs_block_t efs_validate_vh(struct volume_header *vh) {
157 int i;
158 __be32 cs, *ui;
159 int csum;
160 efs_block_t sblock = 0; /* shuts up gcc */
161 struct pt_types *pt_entry;
162 int pt_type, slice = -1;
163
164 if (be32_to_cpu(vh->vh_magic) != VHMAGIC) {
165 /*
166 * assume that we're dealing with a partition and allow
167 * read_super() to try and detect a valid superblock
168 * on the next block.
169 */
170 return 0;
171 }
172
173 ui = ((__be32 *) (vh + 1)) - 1;
174 for(csum = 0; ui >= ((__be32 *) vh);) {
175 cs = *ui--;
176 csum += be32_to_cpu(cs);
177 }
178 if (csum) {
f403d1db 179 pr_warn("SGI disklabel: checksum bad, label corrupted\n");
1da177e4
LT
180 return 0;
181 }
182
183#ifdef DEBUG
d1826f2a 184 pr_debug("bf: \"%16s\"\n", vh->vh_bootfile);
1da177e4
LT
185
186 for(i = 0; i < NVDIR; i++) {
187 int j;
188 char name[VDNAMESIZE+1];
189
190 for(j = 0; j < VDNAMESIZE; j++) {
191 name[j] = vh->vh_vd[i].vd_name[j];
192 }
193 name[j] = (char) 0;
194
195 if (name[0]) {
d1826f2a
FF
196 pr_debug("vh: %8s block: 0x%08x size: 0x%08x\n",
197 name, (int) be32_to_cpu(vh->vh_vd[i].vd_lbn),
1da177e4
LT
198 (int) be32_to_cpu(vh->vh_vd[i].vd_nbytes));
199 }
200 }
201#endif
202
203 for(i = 0; i < NPARTAB; i++) {
204 pt_type = (int) be32_to_cpu(vh->vh_pt[i].pt_type);
205 for(pt_entry = sgi_pt_types; pt_entry->pt_name; pt_entry++) {
206 if (pt_type == pt_entry->pt_type) break;
207 }
208#ifdef DEBUG
209 if (be32_to_cpu(vh->vh_pt[i].pt_nblks)) {
d1826f2a
FF
210 pr_debug("pt %2d: start: %08d size: %08d type: 0x%02x (%s)\n",
211 i, (int)be32_to_cpu(vh->vh_pt[i].pt_firstlbn),
212 (int)be32_to_cpu(vh->vh_pt[i].pt_nblks),
213 pt_type, (pt_entry->pt_name) ?
214 pt_entry->pt_name : "unknown");
1da177e4
LT
215 }
216#endif
217 if (IS_EFS(pt_type)) {
218 sblock = be32_to_cpu(vh->vh_pt[i].pt_firstlbn);
219 slice = i;
220 }
221 }
222
223 if (slice == -1) {
f403d1db 224 pr_notice("partition table contained no EFS partitions\n");
1da177e4
LT
225#ifdef DEBUG
226 } else {
f403d1db 227 pr_info("using slice %d (type %s, offset 0x%x)\n", slice,
1da177e4
LT
228 (pt_entry->pt_name) ? pt_entry->pt_name : "unknown",
229 sblock);
230#endif
231 }
014c2544 232 return sblock;
1da177e4
LT
233}
234
235static int efs_validate_super(struct efs_sb_info *sb, struct efs_super *super) {
236
014c2544
JJ
237 if (!IS_EFS_MAGIC(be32_to_cpu(super->fs_magic)))
238 return -1;
1da177e4
LT
239
240 sb->fs_magic = be32_to_cpu(super->fs_magic);
241 sb->total_blocks = be32_to_cpu(super->fs_size);
242 sb->first_block = be32_to_cpu(super->fs_firstcg);
243 sb->group_size = be32_to_cpu(super->fs_cgfsize);
244 sb->data_free = be32_to_cpu(super->fs_tfree);
245 sb->inode_free = be32_to_cpu(super->fs_tinode);
246 sb->inode_blocks = be16_to_cpu(super->fs_cgisize);
247 sb->total_groups = be16_to_cpu(super->fs_ncg);
248
249 return 0;
250}
251
252static int efs_fill_super(struct super_block *s, void *d, int silent)
253{
254 struct efs_sb_info *sb;
255 struct buffer_head *bh;
256 struct inode *root;
257
f8314dc6 258 sb = kzalloc(sizeof(struct efs_sb_info), GFP_KERNEL);
1da177e4
LT
259 if (!sb)
260 return -ENOMEM;
261 s->s_fs_info = sb;
22b13969
DD
262 s->s_time_min = 0;
263 s->s_time_max = U32_MAX;
1da177e4
LT
264
265 s->s_magic = EFS_SUPER_MAGIC;
266 if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {
f403d1db 267 pr_err("device does not support %d byte blocks\n",
1da177e4 268 EFS_BLOCKSIZE);
5a9ed6f5 269 return -EINVAL;
1da177e4
LT
270 }
271
272 /* read the vh (volume header) block */
273 bh = sb_bread(s, 0);
274
275 if (!bh) {
f403d1db 276 pr_err("cannot read volume header\n");
4108124f 277 return -EIO;
1da177e4
LT
278 }
279
280 /*
281 * if this returns zero then we didn't find any partition table.
282 * this isn't (yet) an error - just assume for the moment that
283 * the device is valid and go on to search for a superblock.
284 */
285 sb->fs_start = efs_validate_vh((struct volume_header *) bh->b_data);
286 brelse(bh);
287
288 if (sb->fs_start == -1) {
5a9ed6f5 289 return -EINVAL;
1da177e4
LT
290 }
291
292 bh = sb_bread(s, sb->fs_start + EFS_SUPER);
293 if (!bh) {
f403d1db 294 pr_err("cannot read superblock\n");
4108124f 295 return -EIO;
1da177e4
LT
296 }
297
298 if (efs_validate_super(sb, (struct efs_super *) bh->b_data)) {
299#ifdef DEBUG
f403d1db
FF
300 pr_warn("invalid superblock at block %u\n",
301 sb->fs_start + EFS_SUPER);
1da177e4
LT
302#endif
303 brelse(bh);
5a9ed6f5 304 return -EINVAL;
1da177e4
LT
305 }
306 brelse(bh);
307
bc98a42c 308 if (!sb_rdonly(s)) {
1da177e4 309#ifdef DEBUG
f403d1db 310 pr_info("forcing read-only mode\n");
1da177e4 311#endif
1751e8a6 312 s->s_flags |= SB_RDONLY;
1da177e4
LT
313 }
314 s->s_op = &efs_superblock_operations;
315 s->s_export_op = &efs_export_ops;
298384cd
DH
316 root = efs_iget(s, EFS_ROOTINODE);
317 if (IS_ERR(root)) {
f403d1db 318 pr_err("get root inode failed\n");
5a9ed6f5 319 return PTR_ERR(root);
298384cd
DH
320 }
321
48fde701 322 s->s_root = d_make_root(root);
1da177e4 323 if (!(s->s_root)) {
f403d1db 324 pr_err("get root dentry failed\n");
5a9ed6f5 325 return -ENOMEM;
1da177e4
LT
326 }
327
328 return 0;
1da177e4
LT
329}
330
726c3342 331static int efs_statfs(struct dentry *dentry, struct kstatfs *buf) {
514c91a9
CL
332 struct super_block *sb = dentry->d_sb;
333 struct efs_sb_info *sbi = SUPER_INFO(sb);
334 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
1da177e4
LT
335
336 buf->f_type = EFS_SUPER_MAGIC; /* efs magic number */
337 buf->f_bsize = EFS_BLOCKSIZE; /* blocksize */
514c91a9
CL
338 buf->f_blocks = sbi->total_groups * /* total data blocks */
339 (sbi->group_size - sbi->inode_blocks);
340 buf->f_bfree = sbi->data_free; /* free data blocks */
341 buf->f_bavail = sbi->data_free; /* free blocks for non-root */
342 buf->f_files = sbi->total_groups * /* total inodes */
343 sbi->inode_blocks *
1da177e4 344 (EFS_BLOCKSIZE / sizeof(struct efs_dinode));
514c91a9 345 buf->f_ffree = sbi->inode_free; /* free inodes */
6d1349c7 346 buf->f_fsid = u64_to_fsid(id);
1da177e4
LT
347 buf->f_namelen = EFS_MAXNAMELEN; /* max filename length */
348
349 return 0;
350}
351