iget: stop BFS from using iget() and read_inode()
[linux-2.6.git] / fs / bfs / dir.c
1 /*
2  *      fs/bfs/dir.c
3  *      BFS directory operations.
4  *      Copyright (C) 1999,2000  Tigran Aivazian <tigran@veritas.com>
5  *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005
6  */
7
8 #include <linux/time.h>
9 #include <linux/string.h>
10 #include <linux/fs.h>
11 #include <linux/smp_lock.h>
12 #include <linux/buffer_head.h>
13 #include <linux/sched.h>
14 #include "bfs.h"
15
16 #undef DEBUG
17
18 #ifdef DEBUG
19 #define dprintf(x...)   printf(x)
20 #else
21 #define dprintf(x...)
22 #endif
23
24 static int bfs_add_entry(struct inode *dir, const unsigned char *name,
25                                                 int namelen, int ino);
26 static struct buffer_head *bfs_find_entry(struct inode *dir,
27                                 const unsigned char *name, int namelen,
28                                 struct bfs_dirent **res_dir);
29
30 static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir)
31 {
32         struct inode *dir = f->f_path.dentry->d_inode;
33         struct buffer_head *bh;
34         struct bfs_dirent *de;
35         unsigned int offset;
36         int block;
37
38         lock_kernel();
39
40         if (f->f_pos & (BFS_DIRENT_SIZE - 1)) {
41                 printf("Bad f_pos=%08lx for %s:%08lx\n",
42                                         (unsigned long)f->f_pos,
43                                         dir->i_sb->s_id, dir->i_ino);
44                 unlock_kernel();
45                 return -EBADF;
46         }
47
48         while (f->f_pos < dir->i_size) {
49                 offset = f->f_pos & (BFS_BSIZE - 1);
50                 block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS);
51                 bh = sb_bread(dir->i_sb, block);
52                 if (!bh) {
53                         f->f_pos += BFS_BSIZE - offset;
54                         continue;
55                 }
56                 do {
57                         de = (struct bfs_dirent *)(bh->b_data + offset);
58                         if (de->ino) {
59                                 int size = strnlen(de->name, BFS_NAMELEN);
60                                 if (filldir(dirent, de->name, size, f->f_pos,
61                                                 le16_to_cpu(de->ino),
62                                                 DT_UNKNOWN) < 0) {
63                                         brelse(bh);
64                                         unlock_kernel();
65                                         return 0;
66                                 }
67                         }
68                         offset += BFS_DIRENT_SIZE;
69                         f->f_pos += BFS_DIRENT_SIZE;
70                 } while ((offset < BFS_BSIZE) && (f->f_pos < dir->i_size));
71                 brelse(bh);
72         }
73
74         unlock_kernel();
75         return 0;       
76 }
77
78 const struct file_operations bfs_dir_operations = {
79         .read           = generic_read_dir,
80         .readdir        = bfs_readdir,
81         .fsync          = file_fsync,
82 };
83
84 extern void dump_imap(const char *, struct super_block *);
85
86 static int bfs_create(struct inode *dir, struct dentry *dentry, int mode,
87                                                 struct nameidata *nd)
88 {
89         int err;
90         struct inode *inode;
91         struct super_block *s = dir->i_sb;
92         struct bfs_sb_info *info = BFS_SB(s);
93         unsigned long ino;
94
95         inode = new_inode(s);
96         if (!inode)
97                 return -ENOSPC;
98         lock_kernel();
99         ino = find_first_zero_bit(info->si_imap, info->si_lasti);
100         if (ino > info->si_lasti) {
101                 unlock_kernel();
102                 iput(inode);
103                 return -ENOSPC;
104         }
105         set_bit(ino, info->si_imap);
106         info->si_freei--;
107         inode->i_uid = current->fsuid;
108         inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
109         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
110         inode->i_blocks = 0;
111         inode->i_op = &bfs_file_inops;
112         inode->i_fop = &bfs_file_operations;
113         inode->i_mapping->a_ops = &bfs_aops;
114         inode->i_mode = mode;
115         inode->i_ino = ino;
116         BFS_I(inode)->i_dsk_ino = ino;
117         BFS_I(inode)->i_sblock = 0;
118         BFS_I(inode)->i_eblock = 0;
119         insert_inode_hash(inode);
120         mark_inode_dirty(inode);
121         dump_imap("create", s);
122
123         err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
124                                                         inode->i_ino);
125         if (err) {
126                 inode_dec_link_count(inode);
127                 iput(inode);
128                 unlock_kernel();
129                 return err;
130         }
131         unlock_kernel();
132         d_instantiate(dentry, inode);
133         return 0;
134 }
135
136 static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
137                                                 struct nameidata *nd)
138 {
139         struct inode *inode = NULL;
140         struct buffer_head *bh;
141         struct bfs_dirent *de;
142
143         if (dentry->d_name.len > BFS_NAMELEN)
144                 return ERR_PTR(-ENAMETOOLONG);
145
146         lock_kernel();
147         bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
148         if (bh) {
149                 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
150                 brelse(bh);
151                 inode = bfs_iget(dir->i_sb, ino);
152                 if (IS_ERR(inode)) {
153                         unlock_kernel();
154                         return ERR_CAST(inode);
155                 }
156         }
157         unlock_kernel();
158         d_add(dentry, inode);
159         return NULL;
160 }
161
162 static int bfs_link(struct dentry *old, struct inode *dir,
163                                                 struct dentry *new)
164 {
165         struct inode *inode = old->d_inode;
166         int err;
167
168         lock_kernel();
169         err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
170                                                         inode->i_ino);
171         if (err) {
172                 unlock_kernel();
173                 return err;
174         }
175         inc_nlink(inode);
176         inode->i_ctime = CURRENT_TIME_SEC;
177         mark_inode_dirty(inode);
178         atomic_inc(&inode->i_count);
179         d_instantiate(new, inode);
180         unlock_kernel();
181         return 0;
182 }
183
184 static int bfs_unlink(struct inode *dir, struct dentry *dentry)
185 {
186         int error = -ENOENT;
187         struct inode *inode;
188         struct buffer_head *bh;
189         struct bfs_dirent *de;
190
191         inode = dentry->d_inode;
192         lock_kernel();
193         bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
194         if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
195                 goto out_brelse;
196
197         if (!inode->i_nlink) {
198                 printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
199                                         inode->i_sb->s_id, inode->i_ino,
200                                         inode->i_nlink);
201                 inode->i_nlink = 1;
202         }
203         de->ino = 0;
204         mark_buffer_dirty(bh);
205         dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
206         mark_inode_dirty(dir);
207         inode->i_ctime = dir->i_ctime;
208         inode_dec_link_count(inode);
209         error = 0;
210
211 out_brelse:
212         brelse(bh);
213         unlock_kernel();
214         return error;
215 }
216
217 static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
218                         struct inode *new_dir, struct dentry *new_dentry)
219 {
220         struct inode *old_inode, *new_inode;
221         struct buffer_head *old_bh, *new_bh;
222         struct bfs_dirent *old_de, *new_de;
223         int error = -ENOENT;
224
225         old_bh = new_bh = NULL;
226         old_inode = old_dentry->d_inode;
227         if (S_ISDIR(old_inode->i_mode))
228                 return -EINVAL;
229
230         lock_kernel();
231         old_bh = bfs_find_entry(old_dir, 
232                                 old_dentry->d_name.name, 
233                                 old_dentry->d_name.len, &old_de);
234
235         if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
236                 goto end_rename;
237
238         error = -EPERM;
239         new_inode = new_dentry->d_inode;
240         new_bh = bfs_find_entry(new_dir, 
241                                 new_dentry->d_name.name, 
242                                 new_dentry->d_name.len, &new_de);
243
244         if (new_bh && !new_inode) {
245                 brelse(new_bh);
246                 new_bh = NULL;
247         }
248         if (!new_bh) {
249                 error = bfs_add_entry(new_dir, 
250                                         new_dentry->d_name.name,
251                                         new_dentry->d_name.len,
252                                         old_inode->i_ino);
253                 if (error)
254                         goto end_rename;
255         }
256         old_de->ino = 0;
257         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
258         mark_inode_dirty(old_dir);
259         if (new_inode) {
260                 new_inode->i_ctime = CURRENT_TIME_SEC;
261                 inode_dec_link_count(new_inode);
262         }
263         mark_buffer_dirty(old_bh);
264         error = 0;
265
266 end_rename:
267         unlock_kernel();
268         brelse(old_bh);
269         brelse(new_bh);
270         return error;
271 }
272
273 const struct inode_operations bfs_dir_inops = {
274         .create                 = bfs_create,
275         .lookup                 = bfs_lookup,
276         .link                   = bfs_link,
277         .unlink                 = bfs_unlink,
278         .rename                 = bfs_rename,
279 };
280
281 static int bfs_add_entry(struct inode *dir, const unsigned char *name,
282                                                         int namelen, int ino)
283 {
284         struct buffer_head *bh;
285         struct bfs_dirent *de;
286         int block, sblock, eblock, off, pos;
287         int i;
288
289         dprintf("name=%s, namelen=%d\n", name, namelen);
290
291         if (!namelen)
292                 return -ENOENT;
293         if (namelen > BFS_NAMELEN)
294                 return -ENAMETOOLONG;
295
296         sblock = BFS_I(dir)->i_sblock;
297         eblock = BFS_I(dir)->i_eblock;
298         for (block = sblock; block <= eblock; block++) {
299                 bh = sb_bread(dir->i_sb, block);
300                 if (!bh)
301                         return -ENOSPC;
302                 for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
303                         de = (struct bfs_dirent *)(bh->b_data + off);
304                         if (!de->ino) {
305                                 pos = (block - sblock) * BFS_BSIZE + off;
306                                 if (pos >= dir->i_size) {
307                                         dir->i_size += BFS_DIRENT_SIZE;
308                                         dir->i_ctime = CURRENT_TIME_SEC;
309                                 }
310                                 dir->i_mtime = CURRENT_TIME_SEC;
311                                 mark_inode_dirty(dir);
312                                 de->ino = cpu_to_le16((u16)ino);
313                                 for (i = 0; i < BFS_NAMELEN; i++)
314                                         de->name[i] =
315                                                 (i < namelen) ? name[i] : 0;
316                                 mark_buffer_dirty(bh);
317                                 brelse(bh);
318                                 return 0;
319                         }
320                 }
321                 brelse(bh);
322         }
323         return -ENOSPC;
324 }
325
326 static inline int bfs_namecmp(int len, const unsigned char *name,
327                                                         const char *buffer)
328 {
329         if ((len < BFS_NAMELEN) && buffer[len])
330                 return 0;
331         return !memcmp(name, buffer, len);
332 }
333
334 static struct buffer_head *bfs_find_entry(struct inode *dir,
335                         const unsigned char *name, int namelen,
336                         struct bfs_dirent **res_dir)
337 {
338         unsigned long block = 0, offset = 0;
339         struct buffer_head *bh = NULL;
340         struct bfs_dirent *de;
341
342         *res_dir = NULL;
343         if (namelen > BFS_NAMELEN)
344                 return NULL;
345
346         while (block * BFS_BSIZE + offset < dir->i_size) {
347                 if (!bh) {
348                         bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
349                         if (!bh) {
350                                 block++;
351                                 continue;
352                         }
353                 }
354                 de = (struct bfs_dirent *)(bh->b_data + offset);
355                 offset += BFS_DIRENT_SIZE;
356                 if (le16_to_cpu(de->ino) &&
357                                 bfs_namecmp(namelen, name, de->name)) {
358                         *res_dir = de;
359                         return bh;
360                 }
361                 if (offset < bh->b_size)
362                         continue;
363                 brelse(bh);
364                 bh = NULL;
365                 offset = 0;
366                 block++;
367         }
368         brelse(bh);
369         return NULL;
370 }