858fb72f9e0fa76a7b2214bb518537733bc1dea4
[platform/kernel/linux-exynos.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         mutex_lock(&sbi->s_lock);
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         old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
47         if (sbi->s_type == FSTYPE_SYSV4) {
48                 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
49                         *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
50                 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
51                 mark_buffer_dirty(sbi->s_bh2);
52         }
53
54         mutex_unlock(&sbi->s_lock);
55
56         return 0;
57 }
58
59 static int sysv_remount(struct super_block *sb, int *flags, char *data)
60 {
61         struct sysv_sb_info *sbi = SYSV_SB(sb);
62
63         sync_filesystem(sb);
64         if (sbi->s_forced_ro)
65                 *flags |= MS_RDONLY;
66         return 0;
67 }
68
69 static void sysv_put_super(struct super_block *sb)
70 {
71         struct sysv_sb_info *sbi = SYSV_SB(sb);
72
73         if (!(sb->s_flags & MS_RDONLY)) {
74                 /* XXX ext2 also updates the state here */
75                 mark_buffer_dirty(sbi->s_bh1);
76                 if (sbi->s_bh1 != sbi->s_bh2)
77                         mark_buffer_dirty(sbi->s_bh2);
78         }
79
80         brelse(sbi->s_bh1);
81         if (sbi->s_bh1 != sbi->s_bh2)
82                 brelse(sbi->s_bh2);
83
84         kfree(sbi);
85 }
86
87 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
88 {
89         struct super_block *sb = dentry->d_sb;
90         struct sysv_sb_info *sbi = SYSV_SB(sb);
91         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
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         buf->f_fsid.val[0] = (u32)id;
101         buf->f_fsid.val[1] = (u32)(id >> 32);
102         return 0;
103 }
104
105 /* 
106  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
107  */
108 static inline void read3byte(struct sysv_sb_info *sbi,
109         unsigned char * from, unsigned char * to)
110 {
111         if (sbi->s_bytesex == BYTESEX_PDP) {
112                 to[0] = from[0];
113                 to[1] = 0;
114                 to[2] = from[1];
115                 to[3] = from[2];
116         } else if (sbi->s_bytesex == BYTESEX_LE) {
117                 to[0] = from[0];
118                 to[1] = from[1];
119                 to[2] = from[2];
120                 to[3] = 0;
121         } else {
122                 to[0] = 0;
123                 to[1] = from[0];
124                 to[2] = from[1];
125                 to[3] = from[2];
126         }
127 }
128
129 static inline void write3byte(struct sysv_sb_info *sbi,
130         unsigned char * from, unsigned char * to)
131 {
132         if (sbi->s_bytesex == BYTESEX_PDP) {
133                 to[0] = from[0];
134                 to[1] = from[2];
135                 to[2] = from[3];
136         } else if (sbi->s_bytesex == BYTESEX_LE) {
137                 to[0] = from[0];
138                 to[1] = from[1];
139                 to[2] = from[2];
140         } else {
141                 to[0] = from[1];
142                 to[1] = from[2];
143                 to[2] = from[3];
144         }
145 }
146
147 static const struct inode_operations sysv_symlink_inode_operations = {
148         .get_link       = page_get_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                 inode->i_op = &sysv_symlink_inode_operations;
164                 inode_nohighmem(inode);
165                 inode->i_mapping->a_ops = &sysv_aops;
166         } else
167                 init_special_inode(inode, inode->i_mode, rdev);
168 }
169
170 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
171 {
172         struct sysv_sb_info * sbi = SYSV_SB(sb);
173         struct buffer_head * bh;
174         struct sysv_inode * raw_inode;
175         struct sysv_inode_info * si;
176         struct inode *inode;
177         unsigned int block;
178
179         if (!ino || ino > sbi->s_ninodes) {
180                 printk("Bad inode number on dev %s: %d is out of range\n",
181                        sb->s_id, ino);
182                 return ERR_PTR(-EIO);
183         }
184
185         inode = iget_locked(sb, ino);
186         if (!inode)
187                 return ERR_PTR(-ENOMEM);
188         if (!(inode->i_state & I_NEW))
189                 return inode;
190
191         raw_inode = sysv_raw_inode(sb, ino, &bh);
192         if (!raw_inode) {
193                 printk("Major problem: unable to read inode from dev %s\n",
194                        inode->i_sb->s_id);
195                 goto bad_inode;
196         }
197         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
198         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
199         i_uid_write(inode, (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid));
200         i_gid_write(inode, (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid));
201         set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink));
202         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
203         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
204         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
205         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
206         inode->i_ctime.tv_nsec = 0;
207         inode->i_atime.tv_nsec = 0;
208         inode->i_mtime.tv_nsec = 0;
209         inode->i_blocks = 0;
210
211         si = SYSV_I(inode);
212         for (block = 0; block < 10+1+1+1; block++)
213                 read3byte(sbi, &raw_inode->i_data[3*block],
214                                 (u8 *)&si->i_data[block]);
215         brelse(bh);
216         si->i_dir_start_lookup = 0;
217         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
218                 sysv_set_inode(inode,
219                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
220         else
221                 sysv_set_inode(inode, 0);
222         unlock_new_inode(inode);
223         return inode;
224
225 bad_inode:
226         iget_failed(inode);
227         return ERR_PTR(-EIO);
228 }
229
230 static int __sysv_write_inode(struct inode *inode, int wait)
231 {
232         struct super_block * sb = inode->i_sb;
233         struct sysv_sb_info * sbi = SYSV_SB(sb);
234         struct buffer_head * bh;
235         struct sysv_inode * raw_inode;
236         struct sysv_inode_info * si;
237         unsigned int ino, block;
238         int err = 0;
239
240         ino = inode->i_ino;
241         if (!ino || ino > sbi->s_ninodes) {
242                 printk("Bad inode number on dev %s: %d is out of range\n",
243                        inode->i_sb->s_id, ino);
244                 return -EIO;
245         }
246         raw_inode = sysv_raw_inode(sb, ino, &bh);
247         if (!raw_inode) {
248                 printk("unable to read i-node block\n");
249                 return -EIO;
250         }
251
252         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
253         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(i_uid_read(inode)));
254         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode)));
255         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
256         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
257         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
258         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
259         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
260
261         si = SYSV_I(inode);
262         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
263                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
264         for (block = 0; block < 10+1+1+1; block++)
265                 write3byte(sbi, (u8 *)&si->i_data[block],
266                         &raw_inode->i_data[3*block]);
267         mark_buffer_dirty(bh);
268         if (wait) {
269                 sync_dirty_buffer(bh);
270                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
271                         printk ("IO error syncing sysv inode [%s:%08x]\n",
272                                 sb->s_id, ino);
273                         err = -EIO;
274                 }
275         }
276         brelse(bh);
277         return 0;
278 }
279
280 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
281 {
282         return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
283 }
284
285 int sysv_sync_inode(struct inode *inode)
286 {
287         return __sysv_write_inode(inode, 1);
288 }
289
290 static void sysv_evict_inode(struct inode *inode)
291 {
292         truncate_inode_pages_final(&inode->i_data);
293         if (!inode->i_nlink) {
294                 inode->i_size = 0;
295                 sysv_truncate(inode);
296         }
297         invalidate_inode_buffers(inode);
298         clear_inode(inode);
299         if (!inode->i_nlink)
300                 sysv_free_inode(inode);
301 }
302
303 static struct kmem_cache *sysv_inode_cachep;
304
305 static struct inode *sysv_alloc_inode(struct super_block *sb)
306 {
307         struct sysv_inode_info *si;
308
309         si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
310         if (!si)
311                 return NULL;
312         return &si->vfs_inode;
313 }
314
315 static void sysv_i_callback(struct rcu_head *head)
316 {
317         struct inode *inode = container_of(head, struct inode, i_rcu);
318         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
319 }
320
321 static void sysv_destroy_inode(struct inode *inode)
322 {
323         call_rcu(&inode->i_rcu, sysv_i_callback);
324 }
325
326 static void init_once(void *p)
327 {
328         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
329
330         inode_init_once(&si->vfs_inode);
331 }
332
333 const struct super_operations sysv_sops = {
334         .alloc_inode    = sysv_alloc_inode,
335         .destroy_inode  = sysv_destroy_inode,
336         .write_inode    = sysv_write_inode,
337         .evict_inode    = sysv_evict_inode,
338         .put_super      = sysv_put_super,
339         .sync_fs        = sysv_sync_fs,
340         .remount_fs     = sysv_remount,
341         .statfs         = sysv_statfs,
342 };
343
344 int __init sysv_init_icache(void)
345 {
346         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
347                         sizeof(struct sysv_inode_info), 0,
348                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT,
349                         init_once);
350         if (!sysv_inode_cachep)
351                 return -ENOMEM;
352         return 0;
353 }
354
355 void sysv_destroy_icache(void)
356 {
357         /*
358          * Make sure all delayed rcu free inodes are flushed before we
359          * destroy cache.
360          */
361         rcu_barrier();
362         kmem_cache_destroy(sysv_inode_cachep);
363 }