xref: /openbmc/linux/fs/sysv/inode.c (revision 9d56dd3b083a3bec56e9da35ce07baca81030b03)
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/highuid.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/buffer_head.h>
28 #include <linux/vfs.h>
29 #include <linux/namei.h>
30 #include <asm/byteorder.h>
31 #include "sysv.h"
32 
33 static int sysv_sync_fs(struct super_block *sb, int wait)
34 {
35 	struct sysv_sb_info *sbi = SYSV_SB(sb);
36 	unsigned long time = get_seconds(), old_time;
37 
38 	lock_super(sb);
39 
40 	/*
41 	 * If we are going to write out the super block,
42 	 * then attach current time stamp.
43 	 * But if the filesystem was marked clean, keep it clean.
44 	 */
45 	old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
46 	if (sbi->s_type == FSTYPE_SYSV4) {
47 		if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
48 			*sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
49 		*sbi->s_sb_time = cpu_to_fs32(sbi, time);
50 		mark_buffer_dirty(sbi->s_bh2);
51 	}
52 
53 	unlock_super(sb);
54 
55 	return 0;
56 }
57 
58 static void sysv_write_super(struct super_block *sb)
59 {
60 	if (!(sb->s_flags & MS_RDONLY))
61 		sysv_sync_fs(sb, 1);
62 	else
63 		sb->s_dirt = 0;
64 }
65 
66 static int sysv_remount(struct super_block *sb, int *flags, char *data)
67 {
68 	struct sysv_sb_info *sbi = SYSV_SB(sb);
69 	lock_super(sb);
70 	if (sbi->s_forced_ro)
71 		*flags |= MS_RDONLY;
72 	if (!(*flags & MS_RDONLY))
73 		sb->s_dirt = 1;
74 	unlock_super(sb);
75 	return 0;
76 }
77 
78 static void sysv_put_super(struct super_block *sb)
79 {
80 	struct sysv_sb_info *sbi = SYSV_SB(sb);
81 
82 	if (sb->s_dirt)
83 		sysv_write_super(sb);
84 
85 	if (!(sb->s_flags & MS_RDONLY)) {
86 		/* XXX ext2 also updates the state here */
87 		mark_buffer_dirty(sbi->s_bh1);
88 		if (sbi->s_bh1 != sbi->s_bh2)
89 			mark_buffer_dirty(sbi->s_bh2);
90 	}
91 
92 	brelse(sbi->s_bh1);
93 	if (sbi->s_bh1 != sbi->s_bh2)
94 		brelse(sbi->s_bh2);
95 
96 	kfree(sbi);
97 }
98 
99 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
100 {
101 	struct super_block *sb = dentry->d_sb;
102 	struct sysv_sb_info *sbi = SYSV_SB(sb);
103 	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
104 
105 	buf->f_type = sb->s_magic;
106 	buf->f_bsize = sb->s_blocksize;
107 	buf->f_blocks = sbi->s_ndatazones;
108 	buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
109 	buf->f_files = sbi->s_ninodes;
110 	buf->f_ffree = sysv_count_free_inodes(sb);
111 	buf->f_namelen = SYSV_NAMELEN;
112 	buf->f_fsid.val[0] = (u32)id;
113 	buf->f_fsid.val[1] = (u32)(id >> 32);
114 	return 0;
115 }
116 
117 /*
118  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
119  */
120 static inline void read3byte(struct sysv_sb_info *sbi,
121 	unsigned char * from, unsigned char * to)
122 {
123 	if (sbi->s_bytesex == BYTESEX_PDP) {
124 		to[0] = from[0];
125 		to[1] = 0;
126 		to[2] = from[1];
127 		to[3] = from[2];
128 	} else if (sbi->s_bytesex == BYTESEX_LE) {
129 		to[0] = from[0];
130 		to[1] = from[1];
131 		to[2] = from[2];
132 		to[3] = 0;
133 	} else {
134 		to[0] = 0;
135 		to[1] = from[0];
136 		to[2] = from[1];
137 		to[3] = from[2];
138 	}
139 }
140 
141 static inline void write3byte(struct sysv_sb_info *sbi,
142 	unsigned char * from, unsigned char * to)
143 {
144 	if (sbi->s_bytesex == BYTESEX_PDP) {
145 		to[0] = from[0];
146 		to[1] = from[2];
147 		to[2] = from[3];
148 	} else if (sbi->s_bytesex == BYTESEX_LE) {
149 		to[0] = from[0];
150 		to[1] = from[1];
151 		to[2] = from[2];
152 	} else {
153 		to[0] = from[1];
154 		to[1] = from[2];
155 		to[2] = from[3];
156 	}
157 }
158 
159 static const struct inode_operations sysv_symlink_inode_operations = {
160 	.readlink	= generic_readlink,
161 	.follow_link	= page_follow_link_light,
162 	.put_link	= page_put_link,
163 	.getattr	= sysv_getattr,
164 };
165 
166 void sysv_set_inode(struct inode *inode, dev_t rdev)
167 {
168 	if (S_ISREG(inode->i_mode)) {
169 		inode->i_op = &sysv_file_inode_operations;
170 		inode->i_fop = &sysv_file_operations;
171 		inode->i_mapping->a_ops = &sysv_aops;
172 	} else if (S_ISDIR(inode->i_mode)) {
173 		inode->i_op = &sysv_dir_inode_operations;
174 		inode->i_fop = &sysv_dir_operations;
175 		inode->i_mapping->a_ops = &sysv_aops;
176 	} else if (S_ISLNK(inode->i_mode)) {
177 		if (inode->i_blocks) {
178 			inode->i_op = &sysv_symlink_inode_operations;
179 			inode->i_mapping->a_ops = &sysv_aops;
180 		} else {
181 			inode->i_op = &sysv_fast_symlink_inode_operations;
182 			nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
183 				sizeof(SYSV_I(inode)->i_data) - 1);
184 		}
185 	} else
186 		init_special_inode(inode, inode->i_mode, rdev);
187 }
188 
189 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
190 {
191 	struct sysv_sb_info * sbi = SYSV_SB(sb);
192 	struct buffer_head * bh;
193 	struct sysv_inode * raw_inode;
194 	struct sysv_inode_info * si;
195 	struct inode *inode;
196 	unsigned int block;
197 
198 	if (!ino || ino > sbi->s_ninodes) {
199 		printk("Bad inode number on dev %s: %d is out of range\n",
200 		       sb->s_id, ino);
201 		return ERR_PTR(-EIO);
202 	}
203 
204 	inode = iget_locked(sb, ino);
205 	if (!inode)
206 		return ERR_PTR(-ENOMEM);
207 	if (!(inode->i_state & I_NEW))
208 		return inode;
209 
210 	raw_inode = sysv_raw_inode(sb, ino, &bh);
211 	if (!raw_inode) {
212 		printk("Major problem: unable to read inode from dev %s\n",
213 		       inode->i_sb->s_id);
214 		goto bad_inode;
215 	}
216 	/* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
217 	inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
218 	inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
219 	inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
220 	inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
221 	inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
222 	inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
223 	inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
224 	inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
225 	inode->i_ctime.tv_nsec = 0;
226 	inode->i_atime.tv_nsec = 0;
227 	inode->i_mtime.tv_nsec = 0;
228 	inode->i_blocks = 0;
229 
230 	si = SYSV_I(inode);
231 	for (block = 0; block < 10+1+1+1; block++)
232 		read3byte(sbi, &raw_inode->i_data[3*block],
233 				(u8 *)&si->i_data[block]);
234 	brelse(bh);
235 	si->i_dir_start_lookup = 0;
236 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
237 		sysv_set_inode(inode,
238 			       old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
239 	else
240 		sysv_set_inode(inode, 0);
241 	unlock_new_inode(inode);
242 	return inode;
243 
244 bad_inode:
245 	iget_failed(inode);
246 	return ERR_PTR(-EIO);
247 }
248 
249 int sysv_write_inode(struct inode *inode, int wait)
250 {
251 	struct super_block * sb = inode->i_sb;
252 	struct sysv_sb_info * sbi = SYSV_SB(sb);
253 	struct buffer_head * bh;
254 	struct sysv_inode * raw_inode;
255 	struct sysv_inode_info * si;
256 	unsigned int ino, block;
257 	int err = 0;
258 
259 	ino = inode->i_ino;
260 	if (!ino || ino > sbi->s_ninodes) {
261 		printk("Bad inode number on dev %s: %d is out of range\n",
262 		       inode->i_sb->s_id, ino);
263 		return -EIO;
264 	}
265 	raw_inode = sysv_raw_inode(sb, ino, &bh);
266 	if (!raw_inode) {
267 		printk("unable to read i-node block\n");
268 		return -EIO;
269 	}
270 
271 	raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
272 	raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
273 	raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
274 	raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
275 	raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
276 	raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
277 	raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
278 	raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
279 
280 	si = SYSV_I(inode);
281 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
282 		si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
283 	for (block = 0; block < 10+1+1+1; block++)
284 		write3byte(sbi, (u8 *)&si->i_data[block],
285 			&raw_inode->i_data[3*block]);
286 	mark_buffer_dirty(bh);
287 	if (wait) {
288                 sync_dirty_buffer(bh);
289                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
290                         printk ("IO error syncing sysv inode [%s:%08x]\n",
291                                 sb->s_id, ino);
292                         err = -EIO;
293                 }
294         }
295 	brelse(bh);
296 	return 0;
297 }
298 
299 int sysv_sync_inode(struct inode *inode)
300 {
301 	return sysv_write_inode(inode, 1);
302 }
303 
304 static void sysv_delete_inode(struct inode *inode)
305 {
306 	truncate_inode_pages(&inode->i_data, 0);
307 	inode->i_size = 0;
308 	sysv_truncate(inode);
309 	sysv_free_inode(inode);
310 }
311 
312 static struct kmem_cache *sysv_inode_cachep;
313 
314 static struct inode *sysv_alloc_inode(struct super_block *sb)
315 {
316 	struct sysv_inode_info *si;
317 
318 	si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
319 	if (!si)
320 		return NULL;
321 	return &si->vfs_inode;
322 }
323 
324 static void sysv_destroy_inode(struct inode *inode)
325 {
326 	kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
327 }
328 
329 static void init_once(void *p)
330 {
331 	struct sysv_inode_info *si = (struct sysv_inode_info *)p;
332 
333 	inode_init_once(&si->vfs_inode);
334 }
335 
336 const struct super_operations sysv_sops = {
337 	.alloc_inode	= sysv_alloc_inode,
338 	.destroy_inode	= sysv_destroy_inode,
339 	.write_inode	= sysv_write_inode,
340 	.delete_inode	= sysv_delete_inode,
341 	.put_super	= sysv_put_super,
342 	.write_super	= sysv_write_super,
343 	.sync_fs	= sysv_sync_fs,
344 	.remount_fs	= sysv_remount,
345 	.statfs		= sysv_statfs,
346 };
347 
348 int __init sysv_init_icache(void)
349 {
350 	sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
351 			sizeof(struct sysv_inode_info), 0,
352 			SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
353 			init_once);
354 	if (!sysv_inode_cachep)
355 		return -ENOMEM;
356 	return 0;
357 }
358 
359 void sysv_destroy_icache(void)
360 {
361 	kmem_cache_destroy(sysv_inode_cachep);
362 }
363