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/writeback.h>
30 #include <linux/namei.h>
31 #include <asm/byteorder.h>
32 #include "sysv.h"
33
sysv_sync_fs(struct super_block * sb,int wait)34 static int sysv_sync_fs(struct super_block *sb, int wait)
35 {
36 struct sysv_sb_info *sbi = SYSV_SB(sb);
37 unsigned long time = get_seconds(), old_time;
38
39 lock_super(sb);
40
41 /*
42 * If we are going to write out the super block,
43 * then attach current time stamp.
44 * But if the filesystem was marked clean, keep it clean.
45 */
46 sb->s_dirt = 0;
47 old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
48 if (sbi->s_type == FSTYPE_SYSV4) {
49 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
50 *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
51 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
52 mark_buffer_dirty(sbi->s_bh2);
53 }
54
55 unlock_super(sb);
56
57 return 0;
58 }
59
sysv_write_super(struct super_block * sb)60 static void sysv_write_super(struct super_block *sb)
61 {
62 if (!(sb->s_flags & MS_RDONLY))
63 sysv_sync_fs(sb, 1);
64 else
65 sb->s_dirt = 0;
66 }
67
sysv_remount(struct super_block * sb,int * flags,char * data)68 static int sysv_remount(struct super_block *sb, int *flags, char *data)
69 {
70 struct sysv_sb_info *sbi = SYSV_SB(sb);
71 lock_super(sb);
72 if (sbi->s_forced_ro)
73 *flags |= MS_RDONLY;
74 if (*flags & MS_RDONLY)
75 sysv_write_super(sb);
76 unlock_super(sb);
77 return 0;
78 }
79
sysv_put_super(struct super_block * sb)80 static void sysv_put_super(struct super_block *sb)
81 {
82 struct sysv_sb_info *sbi = SYSV_SB(sb);
83
84 if (sb->s_dirt)
85 sysv_write_super(sb);
86
87 if (!(sb->s_flags & MS_RDONLY)) {
88 /* XXX ext2 also updates the state here */
89 mark_buffer_dirty(sbi->s_bh1);
90 if (sbi->s_bh1 != sbi->s_bh2)
91 mark_buffer_dirty(sbi->s_bh2);
92 }
93
94 brelse(sbi->s_bh1);
95 if (sbi->s_bh1 != sbi->s_bh2)
96 brelse(sbi->s_bh2);
97
98 kfree(sbi);
99 }
100
sysv_statfs(struct dentry * dentry,struct kstatfs * buf)101 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
102 {
103 struct super_block *sb = dentry->d_sb;
104 struct sysv_sb_info *sbi = SYSV_SB(sb);
105 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
106
107 buf->f_type = sb->s_magic;
108 buf->f_bsize = sb->s_blocksize;
109 buf->f_blocks = sbi->s_ndatazones;
110 buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
111 buf->f_files = sbi->s_ninodes;
112 buf->f_ffree = sysv_count_free_inodes(sb);
113 buf->f_namelen = SYSV_NAMELEN;
114 buf->f_fsid.val[0] = (u32)id;
115 buf->f_fsid.val[1] = (u32)(id >> 32);
116 return 0;
117 }
118
119 /*
120 * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
121 */
read3byte(struct sysv_sb_info * sbi,unsigned char * from,unsigned char * to)122 static inline void read3byte(struct sysv_sb_info *sbi,
123 unsigned char * from, unsigned char * to)
124 {
125 if (sbi->s_bytesex == BYTESEX_PDP) {
126 to[0] = from[0];
127 to[1] = 0;
128 to[2] = from[1];
129 to[3] = from[2];
130 } else if (sbi->s_bytesex == BYTESEX_LE) {
131 to[0] = from[0];
132 to[1] = from[1];
133 to[2] = from[2];
134 to[3] = 0;
135 } else {
136 to[0] = 0;
137 to[1] = from[0];
138 to[2] = from[1];
139 to[3] = from[2];
140 }
141 }
142
write3byte(struct sysv_sb_info * sbi,unsigned char * from,unsigned char * to)143 static inline void write3byte(struct sysv_sb_info *sbi,
144 unsigned char * from, unsigned char * to)
145 {
146 if (sbi->s_bytesex == BYTESEX_PDP) {
147 to[0] = from[0];
148 to[1] = from[2];
149 to[2] = from[3];
150 } else if (sbi->s_bytesex == BYTESEX_LE) {
151 to[0] = from[0];
152 to[1] = from[1];
153 to[2] = from[2];
154 } else {
155 to[0] = from[1];
156 to[1] = from[2];
157 to[2] = from[3];
158 }
159 }
160
161 static const struct inode_operations sysv_symlink_inode_operations = {
162 .readlink = generic_readlink,
163 .follow_link = page_follow_link_light,
164 .put_link = page_put_link,
165 .getattr = sysv_getattr,
166 };
167
sysv_set_inode(struct inode * inode,dev_t rdev)168 void sysv_set_inode(struct inode *inode, dev_t rdev)
169 {
170 if (S_ISREG(inode->i_mode)) {
171 inode->i_op = &sysv_file_inode_operations;
172 inode->i_fop = &sysv_file_operations;
173 inode->i_mapping->a_ops = &sysv_aops;
174 } else if (S_ISDIR(inode->i_mode)) {
175 inode->i_op = &sysv_dir_inode_operations;
176 inode->i_fop = &sysv_dir_operations;
177 inode->i_mapping->a_ops = &sysv_aops;
178 } else if (S_ISLNK(inode->i_mode)) {
179 if (inode->i_blocks) {
180 inode->i_op = &sysv_symlink_inode_operations;
181 inode->i_mapping->a_ops = &sysv_aops;
182 } else {
183 inode->i_op = &sysv_fast_symlink_inode_operations;
184 nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
185 sizeof(SYSV_I(inode)->i_data) - 1);
186 }
187 } else
188 init_special_inode(inode, inode->i_mode, rdev);
189 }
190
sysv_iget(struct super_block * sb,unsigned int ino)191 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
192 {
193 struct sysv_sb_info * sbi = SYSV_SB(sb);
194 struct buffer_head * bh;
195 struct sysv_inode * raw_inode;
196 struct sysv_inode_info * si;
197 struct inode *inode;
198 unsigned int block;
199
200 if (!ino || ino > sbi->s_ninodes) {
201 printk("Bad inode number on dev %s: %d is out of range\n",
202 sb->s_id, ino);
203 return ERR_PTR(-EIO);
204 }
205
206 inode = iget_locked(sb, ino);
207 if (!inode)
208 return ERR_PTR(-ENOMEM);
209 if (!(inode->i_state & I_NEW))
210 return inode;
211
212 raw_inode = sysv_raw_inode(sb, ino, &bh);
213 if (!raw_inode) {
214 printk("Major problem: unable to read inode from dev %s\n",
215 inode->i_sb->s_id);
216 goto bad_inode;
217 }
218 /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
219 inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
220 inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
221 inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
222 set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink));
223 inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
224 inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
225 inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
226 inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
227 inode->i_ctime.tv_nsec = 0;
228 inode->i_atime.tv_nsec = 0;
229 inode->i_mtime.tv_nsec = 0;
230 inode->i_blocks = 0;
231
232 si = SYSV_I(inode);
233 for (block = 0; block < 10+1+1+1; block++)
234 read3byte(sbi, &raw_inode->i_data[3*block],
235 (u8 *)&si->i_data[block]);
236 brelse(bh);
237 si->i_dir_start_lookup = 0;
238 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
239 sysv_set_inode(inode,
240 old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
241 else
242 sysv_set_inode(inode, 0);
243 unlock_new_inode(inode);
244 return inode;
245
246 bad_inode:
247 iget_failed(inode);
248 return ERR_PTR(-EIO);
249 }
250
__sysv_write_inode(struct inode * inode,int wait)251 static int __sysv_write_inode(struct inode *inode, int wait)
252 {
253 struct super_block * sb = inode->i_sb;
254 struct sysv_sb_info * sbi = SYSV_SB(sb);
255 struct buffer_head * bh;
256 struct sysv_inode * raw_inode;
257 struct sysv_inode_info * si;
258 unsigned int ino, block;
259 int err = 0;
260
261 ino = inode->i_ino;
262 if (!ino || ino > sbi->s_ninodes) {
263 printk("Bad inode number on dev %s: %d is out of range\n",
264 inode->i_sb->s_id, ino);
265 return -EIO;
266 }
267 raw_inode = sysv_raw_inode(sb, ino, &bh);
268 if (!raw_inode) {
269 printk("unable to read i-node block\n");
270 return -EIO;
271 }
272
273 raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
274 raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
275 raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
276 raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
277 raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
278 raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
279 raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
280 raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
281
282 si = SYSV_I(inode);
283 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
284 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
285 for (block = 0; block < 10+1+1+1; block++)
286 write3byte(sbi, (u8 *)&si->i_data[block],
287 &raw_inode->i_data[3*block]);
288 mark_buffer_dirty(bh);
289 if (wait) {
290 sync_dirty_buffer(bh);
291 if (buffer_req(bh) && !buffer_uptodate(bh)) {
292 printk ("IO error syncing sysv inode [%s:%08x]\n",
293 sb->s_id, ino);
294 err = -EIO;
295 }
296 }
297 brelse(bh);
298 return 0;
299 }
300
sysv_write_inode(struct inode * inode,struct writeback_control * wbc)301 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
302 {
303 return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
304 }
305
sysv_sync_inode(struct inode * inode)306 int sysv_sync_inode(struct inode *inode)
307 {
308 return __sysv_write_inode(inode, 1);
309 }
310
sysv_evict_inode(struct inode * inode)311 static void sysv_evict_inode(struct inode *inode)
312 {
313 truncate_inode_pages(&inode->i_data, 0);
314 if (!inode->i_nlink) {
315 inode->i_size = 0;
316 sysv_truncate(inode);
317 }
318 invalidate_inode_buffers(inode);
319 end_writeback(inode);
320 if (!inode->i_nlink)
321 sysv_free_inode(inode);
322 }
323
324 static struct kmem_cache *sysv_inode_cachep;
325
sysv_alloc_inode(struct super_block * sb)326 static struct inode *sysv_alloc_inode(struct super_block *sb)
327 {
328 struct sysv_inode_info *si;
329
330 si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
331 if (!si)
332 return NULL;
333 return &si->vfs_inode;
334 }
335
sysv_i_callback(struct rcu_head * head)336 static void sysv_i_callback(struct rcu_head *head)
337 {
338 struct inode *inode = container_of(head, struct inode, i_rcu);
339 kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
340 }
341
sysv_destroy_inode(struct inode * inode)342 static void sysv_destroy_inode(struct inode *inode)
343 {
344 call_rcu(&inode->i_rcu, sysv_i_callback);
345 }
346
init_once(void * p)347 static void init_once(void *p)
348 {
349 struct sysv_inode_info *si = (struct sysv_inode_info *)p;
350
351 inode_init_once(&si->vfs_inode);
352 }
353
354 const struct super_operations sysv_sops = {
355 .alloc_inode = sysv_alloc_inode,
356 .destroy_inode = sysv_destroy_inode,
357 .write_inode = sysv_write_inode,
358 .evict_inode = sysv_evict_inode,
359 .put_super = sysv_put_super,
360 .write_super = sysv_write_super,
361 .sync_fs = sysv_sync_fs,
362 .remount_fs = sysv_remount,
363 .statfs = sysv_statfs,
364 };
365
sysv_init_icache(void)366 int __init sysv_init_icache(void)
367 {
368 sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
369 sizeof(struct sysv_inode_info), 0,
370 SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
371 init_once);
372 if (!sysv_inode_cachep)
373 return -ENOMEM;
374 return 0;
375 }
376
sysv_destroy_icache(void)377 void sysv_destroy_icache(void)
378 {
379 kmem_cache_destroy(sysv_inode_cachep);
380 }
381