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