Merge branch 'topic/jack' into for-linus
[linux-2.6] / fs / sysv / inode.c
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. */
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
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
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
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  */
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
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
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
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
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
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
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
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
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
328 static void sysv_destroy_inode(struct inode *inode)
329 {
330         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
331 }
332
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
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
362 void sysv_destroy_icache(void)
363 {
364         kmem_cache_destroy(sysv_inode_cachep);
365 }