Merge commit 'origin/master' into for-linus/xen/master
[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         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
94
95         buf->f_type = sb->s_magic;
96         buf->f_bsize = sb->s_blocksize;
97         buf->f_blocks = sbi->s_ndatazones;
98         buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
99         buf->f_files = sbi->s_ninodes;
100         buf->f_ffree = sysv_count_free_inodes(sb);
101         buf->f_namelen = SYSV_NAMELEN;
102         buf->f_fsid.val[0] = (u32)id;
103         buf->f_fsid.val[1] = (u32)(id >> 32);
104         return 0;
105 }
106
107 /* 
108  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
109  */
110 static inline void read3byte(struct sysv_sb_info *sbi,
111         unsigned char * from, unsigned char * to)
112 {
113         if (sbi->s_bytesex == BYTESEX_PDP) {
114                 to[0] = from[0];
115                 to[1] = 0;
116                 to[2] = from[1];
117                 to[3] = from[2];
118         } else if (sbi->s_bytesex == BYTESEX_LE) {
119                 to[0] = from[0];
120                 to[1] = from[1];
121                 to[2] = from[2];
122                 to[3] = 0;
123         } else {
124                 to[0] = 0;
125                 to[1] = from[0];
126                 to[2] = from[1];
127                 to[3] = from[2];
128         }
129 }
130
131 static inline void write3byte(struct sysv_sb_info *sbi,
132         unsigned char * from, unsigned char * to)
133 {
134         if (sbi->s_bytesex == BYTESEX_PDP) {
135                 to[0] = from[0];
136                 to[1] = from[2];
137                 to[2] = from[3];
138         } else if (sbi->s_bytesex == BYTESEX_LE) {
139                 to[0] = from[0];
140                 to[1] = from[1];
141                 to[2] = from[2];
142         } else {
143                 to[0] = from[1];
144                 to[1] = from[2];
145                 to[2] = from[3];
146         }
147 }
148
149 static const struct inode_operations sysv_symlink_inode_operations = {
150         .readlink       = generic_readlink,
151         .follow_link    = page_follow_link_light,
152         .put_link       = page_put_link,
153         .getattr        = sysv_getattr,
154 };
155
156 void sysv_set_inode(struct inode *inode, dev_t rdev)
157 {
158         if (S_ISREG(inode->i_mode)) {
159                 inode->i_op = &sysv_file_inode_operations;
160                 inode->i_fop = &sysv_file_operations;
161                 inode->i_mapping->a_ops = &sysv_aops;
162         } else if (S_ISDIR(inode->i_mode)) {
163                 inode->i_op = &sysv_dir_inode_operations;
164                 inode->i_fop = &sysv_dir_operations;
165                 inode->i_mapping->a_ops = &sysv_aops;
166         } else if (S_ISLNK(inode->i_mode)) {
167                 if (inode->i_blocks) {
168                         inode->i_op = &sysv_symlink_inode_operations;
169                         inode->i_mapping->a_ops = &sysv_aops;
170                 } else {
171                         inode->i_op = &sysv_fast_symlink_inode_operations;
172                         nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
173                                 sizeof(SYSV_I(inode)->i_data) - 1);
174                 }
175         } else
176                 init_special_inode(inode, inode->i_mode, rdev);
177 }
178
179 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
180 {
181         struct sysv_sb_info * sbi = SYSV_SB(sb);
182         struct buffer_head * bh;
183         struct sysv_inode * raw_inode;
184         struct sysv_inode_info * si;
185         struct inode *inode;
186         unsigned int block;
187
188         if (!ino || ino > sbi->s_ninodes) {
189                 printk("Bad inode number on dev %s: %d is out of range\n",
190                        sb->s_id, ino);
191                 return ERR_PTR(-EIO);
192         }
193
194         inode = iget_locked(sb, ino);
195         if (!inode)
196                 return ERR_PTR(-ENOMEM);
197         if (!(inode->i_state & I_NEW))
198                 return inode;
199
200         raw_inode = sysv_raw_inode(sb, ino, &bh);
201         if (!raw_inode) {
202                 printk("Major problem: unable to read inode from dev %s\n",
203                        inode->i_sb->s_id);
204                 goto bad_inode;
205         }
206         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
207         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
208         inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
209         inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
210         inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
211         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
212         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
213         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
214         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
215         inode->i_ctime.tv_nsec = 0;
216         inode->i_atime.tv_nsec = 0;
217         inode->i_mtime.tv_nsec = 0;
218         inode->i_blocks = 0;
219
220         si = SYSV_I(inode);
221         for (block = 0; block < 10+1+1+1; block++)
222                 read3byte(sbi, &raw_inode->i_data[3*block],
223                                 (u8 *)&si->i_data[block]);
224         brelse(bh);
225         si->i_dir_start_lookup = 0;
226         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
227                 sysv_set_inode(inode,
228                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
229         else
230                 sysv_set_inode(inode, 0);
231         unlock_new_inode(inode);
232         return inode;
233
234 bad_inode:
235         iget_failed(inode);
236         return ERR_PTR(-EIO);
237 }
238
239 static struct buffer_head * sysv_update_inode(struct inode * inode)
240 {
241         struct super_block * sb = inode->i_sb;
242         struct sysv_sb_info * sbi = SYSV_SB(sb);
243         struct buffer_head * bh;
244         struct sysv_inode * raw_inode;
245         struct sysv_inode_info * si;
246         unsigned int ino, block;
247
248         ino = inode->i_ino;
249         if (!ino || ino > sbi->s_ninodes) {
250                 printk("Bad inode number on dev %s: %d is out of range\n",
251                        inode->i_sb->s_id, ino);
252                 return NULL;
253         }
254         raw_inode = sysv_raw_inode(sb, ino, &bh);
255         if (!raw_inode) {
256                 printk("unable to read i-node block\n");
257                 return NULL;
258         }
259
260         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
261         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
262         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
263         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
264         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
265         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
266         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
267         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
268
269         si = SYSV_I(inode);
270         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
271                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
272         for (block = 0; block < 10+1+1+1; block++)
273                 write3byte(sbi, (u8 *)&si->i_data[block],
274                         &raw_inode->i_data[3*block]);
275         mark_buffer_dirty(bh);
276         return bh;
277 }
278
279 int sysv_write_inode(struct inode * inode, int wait)
280 {
281         struct buffer_head *bh;
282         lock_kernel();
283         bh = sysv_update_inode(inode);
284         brelse(bh);
285         unlock_kernel();
286         return 0;
287 }
288
289 int sysv_sync_inode(struct inode * inode)
290 {
291         int err = 0;
292         struct buffer_head *bh;
293
294         bh = sysv_update_inode(inode);
295         if (bh && buffer_dirty(bh)) {
296                 sync_dirty_buffer(bh);
297                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
298                         printk ("IO error syncing sysv inode [%s:%08lx]\n",
299                                 inode->i_sb->s_id, inode->i_ino);
300                         err = -1;
301                 }
302         }
303         else if (!bh)
304                 err = -1;
305         brelse (bh);
306         return err;
307 }
308
309 static void sysv_delete_inode(struct inode *inode)
310 {
311         truncate_inode_pages(&inode->i_data, 0);
312         inode->i_size = 0;
313         sysv_truncate(inode);
314         lock_kernel();
315         sysv_free_inode(inode);
316         unlock_kernel();
317 }
318
319 static struct kmem_cache *sysv_inode_cachep;
320
321 static struct inode *sysv_alloc_inode(struct super_block *sb)
322 {
323         struct sysv_inode_info *si;
324
325         si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
326         if (!si)
327                 return NULL;
328         return &si->vfs_inode;
329 }
330
331 static void sysv_destroy_inode(struct inode *inode)
332 {
333         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
334 }
335
336 static void init_once(void *p)
337 {
338         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
339
340         inode_init_once(&si->vfs_inode);
341 }
342
343 const struct super_operations sysv_sops = {
344         .alloc_inode    = sysv_alloc_inode,
345         .destroy_inode  = sysv_destroy_inode,
346         .write_inode    = sysv_write_inode,
347         .delete_inode   = sysv_delete_inode,
348         .put_super      = sysv_put_super,
349         .write_super    = sysv_write_super,
350         .remount_fs     = sysv_remount,
351         .statfs         = sysv_statfs,
352 };
353
354 int __init sysv_init_icache(void)
355 {
356         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
357                         sizeof(struct sysv_inode_info), 0,
358                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
359                         init_once);
360         if (!sysv_inode_cachep)
361                 return -ENOMEM;
362         return 0;
363 }
364
365 void sysv_destroy_icache(void)
366 {
367         kmem_cache_destroy(sysv_inode_cachep);
368 }