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 <linux/namei.h>
31 #include <asm/byteorder.h>
32 #include "sysv.h"
33
34 /* This is only called on sync() and umount(), when s_dirt=1. */
sysv_write_super(struct super_block * sb)35 static void sysv_write_super(struct super_block *sb)
36 {
37 struct sysv_sb_info *sbi = SYSV_SB(sb);
38 unsigned long time = get_seconds(), old_time;
39
40 lock_kernel();
41 if (sb->s_flags & MS_RDONLY)
42 goto clean;
43
44 /*
45 * If we are going to write out the super block,
46 * then attach current time stamp.
47 * But if the filesystem was marked clean, keep it clean.
48 */
49 old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
50 if (sbi->s_type == FSTYPE_SYSV4) {
51 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
52 *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
53 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
54 mark_buffer_dirty(sbi->s_bh2);
55 }
56 clean:
57 sb->s_dirt = 0;
58 unlock_kernel();
59 }
60
sysv_remount(struct super_block * sb,int * flags,char * data)61 static int sysv_remount(struct super_block *sb, int *flags, char *data)
62 {
63 struct sysv_sb_info *sbi = SYSV_SB(sb);
64 if (sbi->s_forced_ro)
65 *flags |= MS_RDONLY;
66 if (!(*flags & MS_RDONLY))
67 sb->s_dirt = 1;
68 return 0;
69 }
70
sysv_put_super(struct super_block * sb)71 static void sysv_put_super(struct super_block *sb)
72 {
73 struct sysv_sb_info *sbi = SYSV_SB(sb);
74
75 if (!(sb->s_flags & MS_RDONLY)) {
76 /* XXX ext2 also updates the state here */
77 mark_buffer_dirty(sbi->s_bh1);
78 if (sbi->s_bh1 != sbi->s_bh2)
79 mark_buffer_dirty(sbi->s_bh2);
80 }
81
82 brelse(sbi->s_bh1);
83 if (sbi->s_bh1 != sbi->s_bh2)
84 brelse(sbi->s_bh2);
85
86 kfree(sbi);
87 }
88
sysv_statfs(struct dentry * dentry,struct kstatfs * buf)89 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
90 {
91 struct super_block *sb = dentry->d_sb;
92 struct sysv_sb_info *sbi = SYSV_SB(sb);
93
94 buf->f_type = sb->s_magic;
95 buf->f_bsize = sb->s_blocksize;
96 buf->f_blocks = sbi->s_ndatazones;
97 buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
98 buf->f_files = sbi->s_ninodes;
99 buf->f_ffree = sysv_count_free_inodes(sb);
100 buf->f_namelen = SYSV_NAMELEN;
101 return 0;
102 }
103
104 /*
105 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
106 */
read3byte(struct sysv_sb_info * sbi,unsigned char * from,unsigned char * to)107 static inline void read3byte(struct sysv_sb_info *sbi,
108 unsigned char * from, unsigned char * to)
109 {
110 if (sbi->s_bytesex == BYTESEX_PDP) {
111 to[0] = from[0];
112 to[1] = 0;
113 to[2] = from[1];
114 to[3] = from[2];
115 } else if (sbi->s_bytesex == BYTESEX_LE) {
116 to[0] = from[0];
117 to[1] = from[1];
118 to[2] = from[2];
119 to[3] = 0;
120 } else {
121 to[0] = 0;
122 to[1] = from[0];
123 to[2] = from[1];
124 to[3] = from[2];
125 }
126 }
127
write3byte(struct sysv_sb_info * sbi,unsigned char * from,unsigned char * to)128 static inline void write3byte(struct sysv_sb_info *sbi,
129 unsigned char * from, unsigned char * to)
130 {
131 if (sbi->s_bytesex == BYTESEX_PDP) {
132 to[0] = from[0];
133 to[1] = from[2];
134 to[2] = from[3];
135 } else if (sbi->s_bytesex == BYTESEX_LE) {
136 to[0] = from[0];
137 to[1] = from[1];
138 to[2] = from[2];
139 } else {
140 to[0] = from[1];
141 to[1] = from[2];
142 to[2] = from[3];
143 }
144 }
145
146 static const struct inode_operations sysv_symlink_inode_operations = {
147 .readlink = generic_readlink,
148 .follow_link = page_follow_link_light,
149 .put_link = page_put_link,
150 .getattr = sysv_getattr,
151 };
152
sysv_set_inode(struct inode * inode,dev_t rdev)153 void sysv_set_inode(struct inode *inode, dev_t rdev)
154 {
155 if (S_ISREG(inode->i_mode)) {
156 inode->i_op = &sysv_file_inode_operations;
157 inode->i_fop = &sysv_file_operations;
158 inode->i_mapping->a_ops = &sysv_aops;
159 } else if (S_ISDIR(inode->i_mode)) {
160 inode->i_op = &sysv_dir_inode_operations;
161 inode->i_fop = &sysv_dir_operations;
162 inode->i_mapping->a_ops = &sysv_aops;
163 } else if (S_ISLNK(inode->i_mode)) {
164 if (inode->i_blocks) {
165 inode->i_op = &sysv_symlink_inode_operations;
166 inode->i_mapping->a_ops = &sysv_aops;
167 } else {
168 inode->i_op = &sysv_fast_symlink_inode_operations;
169 nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
170 sizeof(SYSV_I(inode)->i_data) - 1);
171 }
172 } else
173 init_special_inode(inode, inode->i_mode, rdev);
174 }
175
sysv_iget(struct super_block * sb,unsigned int ino)176 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
177 {
178 struct sysv_sb_info * sbi = SYSV_SB(sb);
179 struct buffer_head * bh;
180 struct sysv_inode * raw_inode;
181 struct sysv_inode_info * si;
182 struct inode *inode;
183 unsigned int block;
184
185 if (!ino || ino > sbi->s_ninodes) {
186 printk("Bad inode number on dev %s: %d is out of range\n",
187 sb->s_id, ino);
188 return ERR_PTR(-EIO);
189 }
190
191 inode = iget_locked(sb, ino);
192 if (!inode)
193 return ERR_PTR(-ENOMEM);
194 if (!(inode->i_state & I_NEW))
195 return inode;
196
197 raw_inode = sysv_raw_inode(sb, ino, &bh);
198 if (!raw_inode) {
199 printk("Major problem: unable to read inode from dev %s\n",
200 inode->i_sb->s_id);
201 goto bad_inode;
202 }
203 /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
204 inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
205 inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
206 inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
207 inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
208 inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
209 inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
210 inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
211 inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
212 inode->i_ctime.tv_nsec = 0;
213 inode->i_atime.tv_nsec = 0;
214 inode->i_mtime.tv_nsec = 0;
215 inode->i_blocks = 0;
216
217 si = SYSV_I(inode);
218 for (block = 0; block < 10+1+1+1; block++)
219 read3byte(sbi, &raw_inode->i_data[3*block],
220 (u8 *)&si->i_data[block]);
221 brelse(bh);
222 si->i_dir_start_lookup = 0;
223 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
224 sysv_set_inode(inode,
225 old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
226 else
227 sysv_set_inode(inode, 0);
228 unlock_new_inode(inode);
229 return inode;
230
231 bad_inode:
232 iget_failed(inode);
233 return ERR_PTR(-EIO);
234 }
235
sysv_update_inode(struct inode * inode)236 static struct buffer_head * sysv_update_inode(struct inode * inode)
237 {
238 struct super_block * sb = inode->i_sb;
239 struct sysv_sb_info * sbi = SYSV_SB(sb);
240 struct buffer_head * bh;
241 struct sysv_inode * raw_inode;
242 struct sysv_inode_info * si;
243 unsigned int ino, block;
244
245 ino = inode->i_ino;
246 if (!ino || ino > sbi->s_ninodes) {
247 printk("Bad inode number on dev %s: %d is out of range\n",
248 inode->i_sb->s_id, ino);
249 return NULL;
250 }
251 raw_inode = sysv_raw_inode(sb, ino, &bh);
252 if (!raw_inode) {
253 printk("unable to read i-node block\n");
254 return NULL;
255 }
256
257 raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
258 raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
259 raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
260 raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
261 raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
262 raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
263 raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
264 raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
265
266 si = SYSV_I(inode);
267 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
268 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
269 for (block = 0; block < 10+1+1+1; block++)
270 write3byte(sbi, (u8 *)&si->i_data[block],
271 &raw_inode->i_data[3*block]);
272 mark_buffer_dirty(bh);
273 return bh;
274 }
275
sysv_write_inode(struct inode * inode,int wait)276 int sysv_write_inode(struct inode * inode, int wait)
277 {
278 struct buffer_head *bh;
279 lock_kernel();
280 bh = sysv_update_inode(inode);
281 brelse(bh);
282 unlock_kernel();
283 return 0;
284 }
285
sysv_sync_inode(struct inode * inode)286 int sysv_sync_inode(struct inode * inode)
287 {
288 int err = 0;
289 struct buffer_head *bh;
290
291 bh = sysv_update_inode(inode);
292 if (bh && buffer_dirty(bh)) {
293 sync_dirty_buffer(bh);
294 if (buffer_req(bh) && !buffer_uptodate(bh)) {
295 printk ("IO error syncing sysv inode [%s:%08lx]\n",
296 inode->i_sb->s_id, inode->i_ino);
297 err = -1;
298 }
299 }
300 else if (!bh)
301 err = -1;
302 brelse (bh);
303 return err;
304 }
305
sysv_delete_inode(struct inode * inode)306 static void sysv_delete_inode(struct inode *inode)
307 {
308 truncate_inode_pages(&inode->i_data, 0);
309 inode->i_size = 0;
310 sysv_truncate(inode);
311 lock_kernel();
312 sysv_free_inode(inode);
313 unlock_kernel();
314 }
315
316 static struct kmem_cache *sysv_inode_cachep;
317
sysv_alloc_inode(struct super_block * sb)318 static struct inode *sysv_alloc_inode(struct super_block *sb)
319 {
320 struct sysv_inode_info *si;
321
322 si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
323 if (!si)
324 return NULL;
325 return &si->vfs_inode;
326 }
327
sysv_destroy_inode(struct inode * inode)328 static void sysv_destroy_inode(struct inode *inode)
329 {
330 kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
331 }
332
init_once(void * p)333 static void init_once(void *p)
334 {
335 struct sysv_inode_info *si = (struct sysv_inode_info *)p;
336
337 inode_init_once(&si->vfs_inode);
338 }
339
340 const struct super_operations sysv_sops = {
341 .alloc_inode = sysv_alloc_inode,
342 .destroy_inode = sysv_destroy_inode,
343 .write_inode = sysv_write_inode,
344 .delete_inode = sysv_delete_inode,
345 .put_super = sysv_put_super,
346 .write_super = sysv_write_super,
347 .remount_fs = sysv_remount,
348 .statfs = sysv_statfs,
349 };
350
sysv_init_icache(void)351 int __init sysv_init_icache(void)
352 {
353 sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
354 sizeof(struct sysv_inode_info), 0,
355 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
356 init_once);
357 if (!sysv_inode_cachep)
358 return -ENOMEM;
359 return 0;
360 }
361
sysv_destroy_icache(void)362 void sysv_destroy_icache(void)
363 {
364 kmem_cache_destroy(sysv_inode_cachep);
365 }
366