xref: /openbmc/linux/fs/sysv/inode.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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. */
34 static 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 	}
55 clean:
56 	sb->s_dirt = 0;
57 	unlock_kernel();
58 }
59 
60 static 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 
70 static 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 		/* XXX ext2 also updates the state here */
76 		mark_buffer_dirty(sbi->s_bh1);
77 		if (sbi->s_bh1 != sbi->s_bh2)
78 			mark_buffer_dirty(sbi->s_bh2);
79 	}
80 
81 	brelse(sbi->s_bh1);
82 	if (sbi->s_bh1 != sbi->s_bh2)
83 		brelse(sbi->s_bh2);
84 
85 	kfree(sbi);
86 }
87 
88 static int sysv_statfs(struct super_block *sb, struct kstatfs *buf)
89 {
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  */
105 static 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 
126 static 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 
144 static 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 
151 void 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 
171 static 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 = inode->i_blksize = 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 
218 bad_inode:
219 	make_bad_inode(inode);
220 	return;
221 }
222 
223 static 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 
263 int 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 
273 int 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 
293 static 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 
303 static kmem_cache_t *sysv_inode_cachep;
304 
305 static 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, SLAB_KERNEL);
310 	if (!si)
311 		return NULL;
312 	return &si->vfs_inode;
313 }
314 
315 static void sysv_destroy_inode(struct inode *inode)
316 {
317 	kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
318 }
319 
320 static void init_once(void *p, kmem_cache_t *cachep, unsigned long flags)
321 {
322 	struct sysv_inode_info *si = (struct sysv_inode_info *)p;
323 
324 	if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
325 			SLAB_CTOR_CONSTRUCTOR)
326 		inode_init_once(&si->vfs_inode);
327 }
328 
329 struct super_operations sysv_sops = {
330 	.alloc_inode	= sysv_alloc_inode,
331 	.destroy_inode	= sysv_destroy_inode,
332 	.read_inode	= sysv_read_inode,
333 	.write_inode	= sysv_write_inode,
334 	.delete_inode	= sysv_delete_inode,
335 	.put_super	= sysv_put_super,
336 	.write_super	= sysv_write_super,
337 	.remount_fs	= sysv_remount,
338 	.statfs		= sysv_statfs,
339 };
340 
341 int __init sysv_init_icache(void)
342 {
343 	sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
344 			sizeof(struct sysv_inode_info), 0,
345 			SLAB_RECLAIM_ACCOUNT,
346 			init_once, NULL);
347 	if (!sysv_inode_cachep)
348 		return -ENOMEM;
349 	return 0;
350 }
351 
352 void sysv_destroy_icache(void)
353 {
354 	kmem_cache_destroy(sysv_inode_cachep);
355 }
356