7c4e5d302abb937d3cdbe4903ff52bf941a5a6d3
[linux-3.10.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 static void sysv_read_inode(struct inode *inode)
173 {
174         struct super_block * sb = inode->i_sb;
175         struct sysv_sb_info * sbi = SYSV_SB(sb);
176         struct buffer_head * bh;
177         struct sysv_inode * raw_inode;
178         struct sysv_inode_info * si;
179         unsigned int block, ino = inode->i_ino;
180
181         if (!ino || ino > sbi->s_ninodes) {
182                 printk("Bad inode number on dev %s: %d is out of range\n",
183                        inode->i_sb->s_id, ino);
184                 goto bad_inode;
185         }
186         raw_inode = sysv_raw_inode(sb, ino, &bh);
187         if (!raw_inode) {
188                 printk("Major problem: unable to read inode from dev %s\n",
189                        inode->i_sb->s_id);
190                 goto bad_inode;
191         }
192         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
193         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
194         inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
195         inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
196         inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
197         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
198         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
199         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
200         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
201         inode->i_ctime.tv_nsec = 0;
202         inode->i_atime.tv_nsec = 0;
203         inode->i_mtime.tv_nsec = 0;
204         inode->i_blocks = 0;
205
206         si = SYSV_I(inode);
207         for (block = 0; block < 10+1+1+1; block++)
208                 read3byte(sbi, &raw_inode->i_data[3*block],
209                                 (u8 *)&si->i_data[block]);
210         brelse(bh);
211         si->i_dir_start_lookup = 0;
212         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
213                 sysv_set_inode(inode,
214                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
215         else
216                 sysv_set_inode(inode, 0);
217         return;
218
219 bad_inode:
220         make_bad_inode(inode);
221         return;
222 }
223
224 static struct buffer_head * sysv_update_inode(struct inode * inode)
225 {
226         struct super_block * sb = inode->i_sb;
227         struct sysv_sb_info * sbi = SYSV_SB(sb);
228         struct buffer_head * bh;
229         struct sysv_inode * raw_inode;
230         struct sysv_inode_info * si;
231         unsigned int ino, block;
232
233         ino = inode->i_ino;
234         if (!ino || ino > sbi->s_ninodes) {
235                 printk("Bad inode number on dev %s: %d is out of range\n",
236                        inode->i_sb->s_id, ino);
237                 return NULL;
238         }
239         raw_inode = sysv_raw_inode(sb, ino, &bh);
240         if (!raw_inode) {
241                 printk("unable to read i-node block\n");
242                 return NULL;
243         }
244
245         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
246         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
247         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
248         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
249         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
250         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
251         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
252         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
253
254         si = SYSV_I(inode);
255         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
256                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
257         for (block = 0; block < 10+1+1+1; block++)
258                 write3byte(sbi, (u8 *)&si->i_data[block],
259                         &raw_inode->i_data[3*block]);
260         mark_buffer_dirty(bh);
261         return bh;
262 }
263
264 int sysv_write_inode(struct inode * inode, int wait)
265 {
266         struct buffer_head *bh;
267         lock_kernel();
268         bh = sysv_update_inode(inode);
269         brelse(bh);
270         unlock_kernel();
271         return 0;
272 }
273
274 int sysv_sync_inode(struct inode * inode)
275 {
276         int err = 0;
277         struct buffer_head *bh;
278
279         bh = sysv_update_inode(inode);
280         if (bh && buffer_dirty(bh)) {
281                 sync_dirty_buffer(bh);
282                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
283                         printk ("IO error syncing sysv inode [%s:%08lx]\n",
284                                 inode->i_sb->s_id, inode->i_ino);
285                         err = -1;
286                 }
287         }
288         else if (!bh)
289                 err = -1;
290         brelse (bh);
291         return err;
292 }
293
294 static void sysv_delete_inode(struct inode *inode)
295 {
296         truncate_inode_pages(&inode->i_data, 0);
297         inode->i_size = 0;
298         sysv_truncate(inode);
299         lock_kernel();
300         sysv_free_inode(inode);
301         unlock_kernel();
302 }
303
304 static struct kmem_cache *sysv_inode_cachep;
305
306 static struct inode *sysv_alloc_inode(struct super_block *sb)
307 {
308         struct sysv_inode_info *si;
309
310         si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
311         if (!si)
312                 return NULL;
313         return &si->vfs_inode;
314 }
315
316 static void sysv_destroy_inode(struct inode *inode)
317 {
318         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
319 }
320
321 static void init_once(void *p, struct kmem_cache *cachep, unsigned long flags)
322 {
323         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
324
325         inode_init_once(&si->vfs_inode);
326 }
327
328 const struct super_operations sysv_sops = {
329         .alloc_inode    = sysv_alloc_inode,
330         .destroy_inode  = sysv_destroy_inode,
331         .read_inode     = sysv_read_inode,
332         .write_inode    = sysv_write_inode,
333         .delete_inode   = sysv_delete_inode,
334         .put_super      = sysv_put_super,
335         .write_super    = sysv_write_super,
336         .remount_fs     = sysv_remount,
337         .statfs         = sysv_statfs,
338 };
339
340 int __init sysv_init_icache(void)
341 {
342         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
343                         sizeof(struct sysv_inode_info), 0,
344                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
345                         init_once);
346         if (!sysv_inode_cachep)
347                 return -ENOMEM;
348         return 0;
349 }
350
351 void sysv_destroy_icache(void)
352 {
353         kmem_cache_destroy(sysv_inode_cachep);
354 }