summaryrefslogtreecommitdiffstats
path: root/fs/sysv/inode.c
blob: 81ec6c548c07c0e34db7821cf72e8f0676f3d177 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
/*
 *  linux/fs/sysv/inode.c
 *
 *  minix/inode.c
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  xenix/inode.c
 *  Copyright (C) 1992  Doug Evans
 *
 *  coh/inode.c
 *  Copyright (C) 1993  Pascal Haible, Bruno Haible
 *
 *  sysv/inode.c
 *  Copyright (C) 1993  Paul B. Monday
 *
 *  sysv/inode.c
 *  Copyright (C) 1993  Bruno Haible
 *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
 *
 *  This file contains code for allocating/freeing inodes and for read/writing
 *  the superblock.
 */

#include <linux/smp_lock.h>
#include <linux/highuid.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <asm/byteorder.h>
#include "sysv.h"

/* This is only called on sync() and umount(), when s_dirt=1. */
static void sysv_write_super(struct super_block *sb)
{
	struct sysv_sb_info *sbi = SYSV_SB(sb);
	unsigned long time = get_seconds(), old_time;

	lock_kernel();
	if (sb->s_flags & MS_RDONLY)
		goto clean;

	/*
	 * If we are going to write out the super block,
	 * then attach current time stamp.
	 * But if the filesystem was marked clean, keep it clean.
	 */
	old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
	if (sbi->s_type == FSTYPE_SYSV4) {
		if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
			*sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
		*sbi->s_sb_time = cpu_to_fs32(sbi, time);
		mark_buffer_dirty(sbi->s_bh2);
	}
clean:
	sb->s_dirt = 0;
	unlock_kernel();
}

static int sysv_remount(struct super_block *sb, int *flags, char *data)
{
	struct sysv_sb_info *sbi = SYSV_SB(sb);
	if (sbi->s_forced_ro)
		*flags |= MS_RDONLY;
	if (!(*flags & MS_RDONLY))
		sb->s_dirt = 1;
	return 0;
}

static void sysv_put_super(struct super_block *sb)
{
	struct sysv_sb_info *sbi = SYSV_SB(sb);

	if (!(sb->s_flags & MS_RDONLY)) {
		/* XXX ext2 also updates the state here */
		mark_buffer_dirty(sbi->s_bh1);
		if (sbi->s_bh1 != sbi->s_bh2)
			mark_buffer_dirty(sbi->s_bh2);
	}

	brelse(sbi->s_bh1);
	if (sbi->s_bh1 != sbi->s_bh2)
		brelse(sbi->s_bh2);

	kfree(sbi);
}

static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *sb = dentry->d_sb;
	struct sysv_sb_info *sbi = SYSV_SB(sb);

	buf->f_type = sb->s_magic;
	buf->f_bsize = sb->s_blocksize;
	buf->f_blocks = sbi->s_ndatazones;
	buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
	buf->f_files = sbi->s_ninodes;
	buf->f_ffree = sysv_count_free_inodes(sb);
	buf->f_namelen = SYSV_NAMELEN;
	return 0;
}

/* 
 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
 */
static inline void read3byte(struct sysv_sb_info *sbi,
	unsigned char * from, unsigned char * to)
{
	if (sbi->s_bytesex == BYTESEX_PDP) {
		to[0] = from[0];
		to[1] = 0;
		to[2] = from[1];
		to[3] = from[2];
	} else if (sbi->s_bytesex == BYTESEX_LE) {
		to[0] = from[0];
		to[1] = from[1];
		to[2] = from[2];
		to[3] = 0;
	} else {
		to[0] = 0;
		to[1] = from[0];
		to[2] = from[1];
		to[3] = from[2];
	}
}

static inline void write3byte(struct sysv_sb_info *sbi,
	unsigned char * from, unsigned char * to)
{
	if (sbi->s_bytesex == BYTESEX_PDP) {
		to[0] = from[0];
		to[1] = from[2];
		to[2] = from[3];
	} else if (sbi->s_bytesex == BYTESEX_LE) {
		to[0] = from[0];
		to[1] = from[1];
		to[2] = from[2];
	} else {
		to[0] = from[1];
		to[1] = from[2];
		to[2] = from[3];
	}
}

static const struct inode_operations sysv_symlink_inode_operations = {
	.readlink	= generic_readlink,
	.follow_link	= page_follow_link_light,
	.put_link	= page_put_link,
	.getattr	= sysv_getattr,
};

void sysv_set_inode(struct inode *inode, dev_t rdev)
{
	if (S_ISREG(inode->i_mode)) {
		inode->i_op = &sysv_file_inode_operations;
		inode->i_fop = &sysv_file_operations;
		inode->i_mapping->a_ops = &sysv_aops;
	} else if (S_ISDIR(inode->i_mode)) {
		inode->i_op = &sysv_dir_inode_operations;
		inode->i_fop = &sysv_dir_operations;
		inode->i_mapping->a_ops = &sysv_aops;
	} else if (S_ISLNK(inode->i_mode)) {
		if (inode->i_blocks) {
			inode->i_op = &sysv_symlink_inode_operations;
			inode->i_mapping->a_ops = &sysv_aops;
		} else
			inode->i_op = &sysv_fast_symlink_inode_operations;
	} else
		init_special_inode(inode, inode->i_mode, rdev);
}

static void sysv_read_inode(struct inode *inode)
{
	struct super_block * sb = inode->i_sb;
	struct sysv_sb_info * sbi = SYSV_SB(sb);
	struct buffer_head * bh;
	struct sysv_inode * raw_inode;
	struct sysv_inode_info * si;
	unsigned int block, ino = inode->i_ino;

	if (!ino || ino > sbi->s_ninodes) {
		printk("Bad inode number on dev %s: %d is out of range\n",
		       inode->i_sb->s_id, ino);
		goto bad_inode;
	}
	raw_inode = sysv_raw_inode(sb, ino, &bh);
	if (!raw_inode) {
		printk("Major problem: unable to read inode from dev %s\n",
		       inode->i_sb->s_id);
		goto bad_inode;
	}
	/* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
	inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
	inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
	inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
	inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
	inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
	inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
	inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
	inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
	inode->i_ctime.tv_nsec = 0;
	inode->i_atime.tv_nsec = 0;
	inode->i_mtime.tv_nsec = 0;
	inode->i_blocks = 0;

	si = SYSV_I(inode);
	for (block = 0; block < 10+1+1+1; block++)
		read3byte(sbi, &raw_inode->i_data[3*block],
				(u8 *)&si->i_data[block]);
	brelse(bh);
	si->i_dir_start_lookup = 0;
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		sysv_set_inode(inode,
			       old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
	else
		sysv_set_inode(inode, 0);
	return;

bad_inode:
	make_bad_inode(inode);
	return;
}

static struct buffer_head * sysv_update_inode(struct inode * inode)
{
	struct super_block * sb = inode->i_sb;
	struct sysv_sb_info * sbi = SYSV_SB(sb);
	struct buffer_head * bh;
	struct sysv_inode * raw_inode;
	struct sysv_inode_info * si;
	unsigned int ino, block;

	ino = inode->i_ino;
	if (!ino || ino > sbi->s_ninodes) {
		printk("Bad inode number on dev %s: %d is out of range\n",
		       inode->i_sb->s_id, ino);
		return NULL;
	}
	raw_inode = sysv_raw_inode(sb, ino, &bh);
	if (!raw_inode) {
		printk("unable to read i-node block\n");
		return NULL;
	}

	raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
	raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
	raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
	raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
	raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
	raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
	raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
	raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);

	si = SYSV_I(inode);
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
		si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
	for (block = 0; block < 10+1+1+1; block++)
		write3byte(sbi, (u8 *)&si->i_data[block],
			&raw_inode->i_data[3*block]);
	mark_buffer_dirty(bh);
	return bh;
}

int sysv_write_inode(struct inode * inode, int wait)
{
	struct buffer_head *bh;
	lock_kernel();
	bh = sysv_update_inode(inode);
	brelse(bh);
	unlock_kernel();
	return 0;
}

int sysv_sync_inode(struct inode * inode)
{
        int err = 0;
        struct buffer_head *bh;

        bh = sysv_update_inode(inode);
        if (bh && buffer_dirty(bh)) {
                sync_dirty_buffer(bh);
                if (buffer_req(bh) && !buffer_uptodate(bh)) {
                        printk ("IO error syncing sysv inode [%s:%08lx]\n",
                                inode->i_sb->s_id, inode->i_ino);
                        err = -1;
                }
        }
        else if (!bh)
                err = -1;
        brelse (bh);
        return err;
}

static void sysv_delete_inode(struct inode *inode)
{
	truncate_inode_pages(&inode->i_data, 0);
	inode->i_size = 0;
	sysv_truncate(inode);
	lock_kernel();
	sysv_free_inode(inode);
	unlock_kernel();
}

static struct kmem_cache *sysv_inode_cachep;

static struct inode *sysv_alloc_inode(struct super_block *sb)
{
	struct sysv_inode_info *si;

	si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
	if (!si)
		return NULL;
	return &si->vfs_inode;
}

static void sysv_destroy_inode(struct inode *inode)
{
	kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
}

static void init_once(struct kmem_cache *cachep, void *p)
{
	struct sysv_inode_info *si = (struct sysv_inode_info *)p;

	inode_init_once(&si->vfs_inode);
}

const struct super_operations sysv_sops = {
	.alloc_inode	= sysv_alloc_inode,
	.destroy_inode	= sysv_destroy_inode,
	.read_inode	= sysv_read_inode,
	.write_inode	= sysv_write_inode,
	.delete_inode	= sysv_delete_inode,
	.put_super	= sysv_put_super,
	.write_super	= sysv_write_super,
	.remount_fs	= sysv_remount,
	.statfs		= sysv_statfs,
};

int __init sysv_init_icache(void)
{
	sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
			sizeof(struct sysv_inode_info), 0,
			SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
			init_once);
	if (!sysv_inode_cachep)
		return -ENOMEM;
	return 0;
}

void sysv_destroy_icache(void)
{
	kmem_cache_destroy(sysv_inode_cachep);
}