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