nfsd4: ignore WANT bits in open downgrade
[linux-2.6.git] / 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/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
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
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
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
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
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  */
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
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
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
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         inode->i_nlink = 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
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
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
306 int sysv_sync_inode(struct inode *inode)
307 {
308         return __sysv_write_inode(inode, 1);
309 }
310
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
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
336 static void sysv_i_callback(struct rcu_head *head)
337 {
338         struct inode *inode = container_of(head, struct inode, i_rcu);
339         INIT_LIST_HEAD(&inode->i_dentry);
340         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
341 }
342
343 static void sysv_destroy_inode(struct inode *inode)
344 {
345         call_rcu(&inode->i_rcu, sysv_i_callback);
346 }
347
348 static void init_once(void *p)
349 {
350         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
351
352         inode_init_once(&si->vfs_inode);
353 }
354
355 const struct super_operations sysv_sops = {
356         .alloc_inode    = sysv_alloc_inode,
357         .destroy_inode  = sysv_destroy_inode,
358         .write_inode    = sysv_write_inode,
359         .evict_inode    = sysv_evict_inode,
360         .put_super      = sysv_put_super,
361         .write_super    = sysv_write_super,
362         .sync_fs        = sysv_sync_fs,
363         .remount_fs     = sysv_remount,
364         .statfs         = sysv_statfs,
365 };
366
367 int __init sysv_init_icache(void)
368 {
369         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
370                         sizeof(struct sysv_inode_info), 0,
371                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
372                         init_once);
373         if (!sysv_inode_cachep)
374                 return -ENOMEM;
375         return 0;
376 }
377
378 void sysv_destroy_icache(void)
379 {
380         kmem_cache_destroy(sysv_inode_cachep);
381 }