When simulating ll/sc compute the return EPC before modifying the
[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 <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 }