1/*
2 *  linux/fs/sysv/inode.c
3 *
4 *  minix/inode.c
5 *  Copyright (C) 1991, 1992  Linus Torvalds
6 *
7 *  xenix/inode.c
8 *  Copyright (C) 1992  Doug Evans
9 *
10 *  coh/inode.c
11 *  Copyright (C) 1993  Pascal Haible, Bruno Haible
12 *
13 *  sysv/inode.c
14 *  Copyright (C) 1993  Paul B. Monday
15 *
16 *  sysv/inode.c
17 *  Copyright (C) 1993  Bruno Haible
18 *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
19 *
20 *  This file contains code for allocating/freeing inodes and for read/writing
21 *  the superblock.
22 */
23
24#include <linux/smp_lock.h>
25#include <linux/highuid.h>
26#include <linux/slab.h>
27#include <linux/init.h>
28#include <linux/buffer_head.h>
29#include <linux/vfs.h>
30#include <asm/byteorder.h>
31#include "sysv.h"
32
33/* This is only called on sync() and umount(), when s_dirt=1. */
34static void sysv_write_super(struct super_block *sb)
35{
36	struct sysv_sb_info *sbi = SYSV_SB(sb);
37	unsigned long time = get_seconds(), old_time;
38
39	lock_kernel();
40	if (sb->s_flags & MS_RDONLY)
41		goto clean;
42
43	/*
44	 * If we are going to write out the super block,
45	 * then attach current time stamp.
46	 * But if the filesystem was marked clean, keep it clean.
47	 */
48	old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
49	if (sbi->s_type == FSTYPE_SYSV4) {
50		if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
51			*sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
52		*sbi->s_sb_time = cpu_to_fs32(sbi, time);
53		mark_buffer_dirty(sbi->s_bh2);
54	}
55clean:
56	sb->s_dirt = 0;
57	unlock_kernel();
58}
59
60static int sysv_remount(struct super_block *sb, int *flags, char *data)
61{
62	struct sysv_sb_info *sbi = SYSV_SB(sb);
63	if (sbi->s_forced_ro)
64		*flags |= MS_RDONLY;
65	if (!(*flags & MS_RDONLY))
66		sb->s_dirt = 1;
67	return 0;
68}
69
70static void sysv_put_super(struct super_block *sb)
71{
72	struct sysv_sb_info *sbi = SYSV_SB(sb);
73
74	if (!(sb->s_flags & MS_RDONLY)) {
75		mark_buffer_dirty(sbi->s_bh1);
76		if (sbi->s_bh1 != sbi->s_bh2)
77			mark_buffer_dirty(sbi->s_bh2);
78	}
79
80	brelse(sbi->s_bh1);
81	if (sbi->s_bh1 != sbi->s_bh2)
82		brelse(sbi->s_bh2);
83
84	kfree(sbi);
85}
86
87static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
88{
89	struct super_block *sb = dentry->d_sb;
90	struct sysv_sb_info *sbi = SYSV_SB(sb);
91
92	buf->f_type = sb->s_magic;
93	buf->f_bsize = sb->s_blocksize;
94	buf->f_blocks = sbi->s_ndatazones;
95	buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
96	buf->f_files = sbi->s_ninodes;
97	buf->f_ffree = sysv_count_free_inodes(sb);
98	buf->f_namelen = SYSV_NAMELEN;
99	return 0;
100}
101
102/*
103 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
104 */
105static inline void read3byte(struct sysv_sb_info *sbi,
106	unsigned char * from, unsigned char * to)
107{
108	if (sbi->s_bytesex == BYTESEX_PDP) {
109		to[0] = from[0];
110		to[1] = 0;
111		to[2] = from[1];
112		to[3] = from[2];
113	} else if (sbi->s_bytesex == BYTESEX_LE) {
114		to[0] = from[0];
115		to[1] = from[1];
116		to[2] = from[2];
117		to[3] = 0;
118	} else {
119		to[0] = 0;
120		to[1] = from[0];
121		to[2] = from[1];
122		to[3] = from[2];
123	}
124}
125
126static inline void write3byte(struct sysv_sb_info *sbi,
127	unsigned char * from, unsigned char * to)
128{
129	if (sbi->s_bytesex == BYTESEX_PDP) {
130		to[0] = from[0];
131		to[1] = from[2];
132		to[2] = from[3];
133	} else if (sbi->s_bytesex == BYTESEX_LE) {
134		to[0] = from[0];
135		to[1] = from[1];
136		to[2] = from[2];
137	} else {
138		to[0] = from[1];
139		to[1] = from[2];
140		to[2] = from[3];
141	}
142}
143
144static const struct inode_operations sysv_symlink_inode_operations = {
145	.readlink	= generic_readlink,
146	.follow_link	= page_follow_link_light,
147	.put_link	= page_put_link,
148	.getattr	= sysv_getattr,
149};
150
151void sysv_set_inode(struct inode *inode, dev_t rdev)
152{
153	if (S_ISREG(inode->i_mode)) {
154		inode->i_op = &sysv_file_inode_operations;
155		inode->i_fop = &sysv_file_operations;
156		inode->i_mapping->a_ops = &sysv_aops;
157	} else if (S_ISDIR(inode->i_mode)) {
158		inode->i_op = &sysv_dir_inode_operations;
159		inode->i_fop = &sysv_dir_operations;
160		inode->i_mapping->a_ops = &sysv_aops;
161	} else if (S_ISLNK(inode->i_mode)) {
162		if (inode->i_blocks) {
163			inode->i_op = &sysv_symlink_inode_operations;
164			inode->i_mapping->a_ops = &sysv_aops;
165		} else
166			inode->i_op = &sysv_fast_symlink_inode_operations;
167	} else
168		init_special_inode(inode, inode->i_mode, rdev);
169}
170
171static void sysv_read_inode(struct inode *inode)
172{
173	struct super_block * sb = inode->i_sb;
174	struct sysv_sb_info * sbi = SYSV_SB(sb);
175	struct buffer_head * bh;
176	struct sysv_inode * raw_inode;
177	struct sysv_inode_info * si;
178	unsigned int block, ino = inode->i_ino;
179
180	if (!ino || ino > sbi->s_ninodes) {
181		printk("Bad inode number on dev %s: %d is out of range\n",
182		       inode->i_sb->s_id, ino);
183		goto bad_inode;
184	}
185	raw_inode = sysv_raw_inode(sb, ino, &bh);
186	if (!raw_inode) {
187		printk("Major problem: unable to read inode from dev %s\n",
188		       inode->i_sb->s_id);
189		goto bad_inode;
190	}
191	/* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
192	inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
193	inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
194	inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
195	inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
196	inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
197	inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
198	inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
199	inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
200	inode->i_ctime.tv_nsec = 0;
201	inode->i_atime.tv_nsec = 0;
202	inode->i_mtime.tv_nsec = 0;
203	inode->i_blocks = 0;
204
205	si = SYSV_I(inode);
206	for (block = 0; block < 10+1+1+1; block++)
207		read3byte(sbi, &raw_inode->i_data[3*block],
208				(u8 *)&si->i_data[block]);
209	brelse(bh);
210	si->i_dir_start_lookup = 0;
211	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
212		sysv_set_inode(inode,
213			       old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
214	else
215		sysv_set_inode(inode, 0);
216	return;
217
218bad_inode:
219	make_bad_inode(inode);
220	return;
221}
222
223static struct buffer_head * sysv_update_inode(struct inode * inode)
224{
225	struct super_block * sb = inode->i_sb;
226	struct sysv_sb_info * sbi = SYSV_SB(sb);
227	struct buffer_head * bh;
228	struct sysv_inode * raw_inode;
229	struct sysv_inode_info * si;
230	unsigned int ino, block;
231
232	ino = inode->i_ino;
233	if (!ino || ino > sbi->s_ninodes) {
234		printk("Bad inode number on dev %s: %d is out of range\n",
235		       inode->i_sb->s_id, ino);
236		return NULL;
237	}
238	raw_inode = sysv_raw_inode(sb, ino, &bh);
239	if (!raw_inode) {
240		printk("unable to read i-node block\n");
241		return NULL;
242	}
243
244	raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
245	raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
246	raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
247	raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
248	raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
249	raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
250	raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
251	raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
252
253	si = SYSV_I(inode);
254	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
255		si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
256	for (block = 0; block < 10+1+1+1; block++)
257		write3byte(sbi, (u8 *)&si->i_data[block],
258			&raw_inode->i_data[3*block]);
259	mark_buffer_dirty(bh);
260	return bh;
261}
262
263int sysv_write_inode(struct inode * inode, int wait)
264{
265	struct buffer_head *bh;
266	lock_kernel();
267	bh = sysv_update_inode(inode);
268	brelse(bh);
269	unlock_kernel();
270	return 0;
271}
272
273int sysv_sync_inode(struct inode * inode)
274{
275        int err = 0;
276        struct buffer_head *bh;
277
278        bh = sysv_update_inode(inode);
279        if (bh && buffer_dirty(bh)) {
280                sync_dirty_buffer(bh);
281                if (buffer_req(bh) && !buffer_uptodate(bh)) {
282                        printk ("IO error syncing sysv inode [%s:%08lx]\n",
283                                inode->i_sb->s_id, inode->i_ino);
284                        err = -1;
285                }
286        }
287        else if (!bh)
288                err = -1;
289        brelse (bh);
290        return err;
291}
292
293static void sysv_delete_inode(struct inode *inode)
294{
295	truncate_inode_pages(&inode->i_data, 0);
296	inode->i_size = 0;
297	sysv_truncate(inode);
298	lock_kernel();
299	sysv_free_inode(inode);
300	unlock_kernel();
301}
302
303static struct kmem_cache *sysv_inode_cachep;
304
305static struct inode *sysv_alloc_inode(struct super_block *sb)
306{
307	struct sysv_inode_info *si;
308
309	si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
310	if (!si)
311		return NULL;
312	return &si->vfs_inode;
313}
314
315static void sysv_destroy_inode(struct inode *inode)
316{
317	kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
318}
319
320static void init_once(void *p, struct kmem_cache *cachep, unsigned long flags)
321{
322	struct sysv_inode_info *si = (struct sysv_inode_info *)p;
323
324	inode_init_once(&si->vfs_inode);
325}
326
327const struct super_operations sysv_sops = {
328	.alloc_inode	= sysv_alloc_inode,
329	.destroy_inode	= sysv_destroy_inode,
330	.read_inode	= sysv_read_inode,
331	.write_inode	= sysv_write_inode,
332	.delete_inode	= sysv_delete_inode,
333	.put_super	= sysv_put_super,
334	.write_super	= sysv_write_super,
335	.remount_fs	= sysv_remount,
336	.statfs		= sysv_statfs,
337};
338
339int __init sysv_init_icache(void)
340{
341	sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
342			sizeof(struct sysv_inode_info), 0,
343			SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
344			init_once, NULL);
345	if (!sysv_inode_cachep)
346		return -ENOMEM;
347	return 0;
348}
349
350void sysv_destroy_icache(void)
351{
352	kmem_cache_destroy(sysv_inode_cachep);
353}
354