[PATCH] bfs endianness annotations
[linux-3.10.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, int namelen, int ino);
25 static struct buffer_head * bfs_find_entry(struct inode * dir, 
26         const unsigned char * name, int namelen, struct bfs_dirent ** res_dir);
27
28 static int bfs_readdir(struct file * f, void * dirent, filldir_t filldir)
29 {
30         struct inode * dir = f->f_dentry->d_inode;
31         struct buffer_head * bh;
32         struct bfs_dirent * de;
33         unsigned int offset;
34         int block;
35
36         lock_kernel();
37
38         if (f->f_pos & (BFS_DIRENT_SIZE-1)) {
39                 printf("Bad f_pos=%08lx for %s:%08lx\n", (unsigned long)f->f_pos, 
40                         dir->i_sb->s_id, dir->i_ino);
41                 unlock_kernel();
42                 return -EBADF;
43         }
44
45         while (f->f_pos < dir->i_size) {
46                 offset = f->f_pos & (BFS_BSIZE-1);
47                 block = BFS_I(dir)->i_sblock + (f->f_pos >> BFS_BSIZE_BITS);
48                 bh = sb_bread(dir->i_sb, block);
49                 if (!bh) {
50                         f->f_pos += BFS_BSIZE - offset;
51                         continue;
52                 }
53                 do {
54                         de = (struct bfs_dirent *)(bh->b_data + offset);
55                         if (de->ino) {
56                                 int size = strnlen(de->name, BFS_NAMELEN);
57                                 if (filldir(dirent, de->name, size, f->f_pos, le16_to_cpu(de->ino), DT_UNKNOWN) < 0) {
58                                         brelse(bh);
59                                         unlock_kernel();
60                                         return 0;
61                                 }
62                         }
63                         offset += BFS_DIRENT_SIZE;
64                         f->f_pos += BFS_DIRENT_SIZE;
65                 } while (offset < BFS_BSIZE && f->f_pos < dir->i_size);
66                 brelse(bh);
67         }
68
69         unlock_kernel();
70         return 0;       
71 }
72
73 struct file_operations bfs_dir_operations = {
74         .read           = generic_read_dir,
75         .readdir        = bfs_readdir,
76         .fsync          = file_fsync,
77 };
78
79 extern void dump_imap(const char *, struct super_block *);
80
81 static int bfs_create(struct inode * dir, struct dentry * dentry, int mode,
82                 struct nameidata *nd)
83 {
84         int err;
85         struct inode * inode;
86         struct super_block * s = dir->i_sb;
87         struct bfs_sb_info * info = BFS_SB(s);
88         unsigned long ino;
89
90         inode = new_inode(s);
91         if (!inode)
92                 return -ENOSPC;
93         lock_kernel();
94         ino = find_first_zero_bit(info->si_imap, info->si_lasti);
95         if (ino > info->si_lasti) {
96                 unlock_kernel();
97                 iput(inode);
98                 return -ENOSPC;
99         }
100         set_bit(ino, info->si_imap);    
101         info->si_freei--;
102         inode->i_uid = current->fsuid;
103         inode->i_gid = (dir->i_mode & S_ISGID) ? dir->i_gid : current->fsgid;
104         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
105         inode->i_blocks = inode->i_blksize = 0;
106         inode->i_op = &bfs_file_inops;
107         inode->i_fop = &bfs_file_operations;
108         inode->i_mapping->a_ops = &bfs_aops;
109         inode->i_mode = mode;
110         inode->i_ino = ino;
111         BFS_I(inode)->i_dsk_ino = ino;
112         BFS_I(inode)->i_sblock = 0;
113         BFS_I(inode)->i_eblock = 0;
114         insert_inode_hash(inode);
115         mark_inode_dirty(inode);
116         dump_imap("create",s);
117
118         err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len, inode->i_ino);
119         if (err) {
120                 inode->i_nlink--;
121                 mark_inode_dirty(inode);
122                 iput(inode);
123                 unlock_kernel();
124                 return err;
125         }
126         unlock_kernel();
127         d_instantiate(dentry, inode);
128         return 0;
129 }
130
131 static struct dentry * bfs_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
132 {
133         struct inode * inode = NULL;
134         struct buffer_head * bh;
135         struct bfs_dirent * de;
136
137         if (dentry->d_name.len > BFS_NAMELEN)
138                 return ERR_PTR(-ENAMETOOLONG);
139
140         lock_kernel();
141         bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
142         if (bh) {
143                 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
144                 brelse(bh);
145                 inode = iget(dir->i_sb, ino);
146                 if (!inode) {
147                         unlock_kernel();
148                         return ERR_PTR(-EACCES);
149                 }
150         }
151         unlock_kernel();
152         d_add(dentry, inode);
153         return NULL;
154 }
155
156 static int bfs_link(struct dentry * old, struct inode * dir, struct dentry * new)
157 {
158         struct inode * inode = old->d_inode;
159         int err;
160
161         lock_kernel();
162         err = bfs_add_entry(dir, new->d_name.name, new->d_name.len, inode->i_ino);
163         if (err) {
164                 unlock_kernel();
165                 return err;
166         }
167         inode->i_nlink++;
168         inode->i_ctime = CURRENT_TIME_SEC;
169         mark_inode_dirty(inode);
170         atomic_inc(&inode->i_count);
171         d_instantiate(new, inode);
172         unlock_kernel();
173         return 0;
174 }
175
176
177 static int bfs_unlink(struct inode * dir, struct dentry * dentry)
178 {
179         int error = -ENOENT;
180         struct inode * inode;
181         struct buffer_head * bh;
182         struct bfs_dirent * de;
183
184         inode = dentry->d_inode;
185         lock_kernel();
186         bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
187         if (!bh || le16_to_cpu(de->ino) != inode->i_ino)
188                 goto out_brelse;
189
190         if (!inode->i_nlink) {
191                 printf("unlinking non-existent file %s:%lu (nlink=%d)\n", inode->i_sb->s_id, 
192                                 inode->i_ino, inode->i_nlink);
193                 inode->i_nlink = 1;
194         }
195         de->ino = 0;
196         mark_buffer_dirty(bh);
197         dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
198         mark_inode_dirty(dir);
199         inode->i_nlink--;
200         inode->i_ctime = dir->i_ctime;
201         mark_inode_dirty(inode);
202         error = 0;
203
204 out_brelse:
205         brelse(bh);
206         unlock_kernel();
207         return error;
208 }
209
210 static int bfs_rename(struct inode * old_dir, struct dentry * old_dentry, 
211                         struct inode * new_dir, struct dentry * new_dentry)
212 {
213         struct inode * old_inode, * new_inode;
214         struct buffer_head * old_bh, * new_bh;
215         struct bfs_dirent * old_de, * new_de;           
216         int error = -ENOENT;
217
218         old_bh = new_bh = NULL;
219         old_inode = old_dentry->d_inode;
220         if (S_ISDIR(old_inode->i_mode))
221                 return -EINVAL;
222
223         lock_kernel();
224         old_bh = bfs_find_entry(old_dir, 
225                                 old_dentry->d_name.name, 
226                                 old_dentry->d_name.len, &old_de);
227
228         if (!old_bh || le16_to_cpu(old_de->ino) != old_inode->i_ino)
229                 goto end_rename;
230
231         error = -EPERM;
232         new_inode = new_dentry->d_inode;
233         new_bh = bfs_find_entry(new_dir, 
234                                 new_dentry->d_name.name, 
235                                 new_dentry->d_name.len, &new_de);
236
237         if (new_bh && !new_inode) {
238                 brelse(new_bh);
239                 new_bh = NULL;
240         }
241         if (!new_bh) {
242                 error = bfs_add_entry(new_dir, 
243                                         new_dentry->d_name.name,
244                                         new_dentry->d_name.len, old_inode->i_ino);
245                 if (error)
246                         goto end_rename;
247         }
248         old_de->ino = 0;
249         old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
250         mark_inode_dirty(old_dir);
251         if (new_inode) {
252                 new_inode->i_nlink--;
253                 new_inode->i_ctime = CURRENT_TIME_SEC;
254                 mark_inode_dirty(new_inode);
255         }
256         mark_buffer_dirty(old_bh);
257         error = 0;
258
259 end_rename:
260         unlock_kernel();
261         brelse(old_bh);
262         brelse(new_bh);
263         return error;
264 }
265
266 struct inode_operations bfs_dir_inops = {
267         .create                 = bfs_create,
268         .lookup                 = bfs_lookup,
269         .link                   = bfs_link,
270         .unlink                 = bfs_unlink,
271         .rename                 = bfs_rename,
272 };
273
274 static int bfs_add_entry(struct inode * dir, const unsigned char * name, int namelen, int ino)
275 {
276         struct buffer_head * bh;
277         struct bfs_dirent * de;
278         int block, sblock, eblock, off, eoff;
279         int i;
280
281         dprintf("name=%s, namelen=%d\n", name, namelen);
282
283         if (!namelen)
284                 return -ENOENT;
285         if (namelen > BFS_NAMELEN)
286                 return -ENAMETOOLONG;
287
288         sblock = BFS_I(dir)->i_sblock;
289         eblock = BFS_I(dir)->i_eblock;
290         eoff = dir->i_size % BFS_BSIZE;
291         for (block=sblock; block<=eblock; block++) {
292                 bh = sb_bread(dir->i_sb, block);
293                 if(!bh) 
294                         return -ENOSPC;
295                 for (off=0; off<BFS_BSIZE; off+=BFS_DIRENT_SIZE) {
296                         de = (struct bfs_dirent *)(bh->b_data + off);
297                         if (block==eblock && off>=eoff) {
298                                 /* Do not read/interpret the garbage in the end of eblock. */
299                                 de->ino = 0;
300                         }
301                         if (!de->ino) {
302                                 if ((block-sblock)*BFS_BSIZE + off >= dir->i_size) {
303                                         dir->i_size += BFS_DIRENT_SIZE;
304                                         dir->i_ctime = CURRENT_TIME_SEC;
305                                 }
306                                 dir->i_mtime = CURRENT_TIME_SEC;
307                                 mark_inode_dirty(dir);
308                                 de->ino = cpu_to_le16((u16)ino);
309                                 for (i=0; i<BFS_NAMELEN; i++)
310                                         de->name[i] = (i < namelen) ? name[i] : 0;
311                                 mark_buffer_dirty(bh);
312                                 brelse(bh);
313                                 return 0;
314                         }
315                 }
316                 brelse(bh);
317         }
318         return -ENOSPC;
319 }
320
321 static inline int bfs_namecmp(int len, const unsigned char * name, const char * buffer)
322 {
323         if (len < BFS_NAMELEN && buffer[len])
324                 return 0;
325         return !memcmp(name, buffer, len);
326 }
327
328 static struct buffer_head * bfs_find_entry(struct inode * dir, 
329         const unsigned char * name, int namelen, struct bfs_dirent ** res_dir)
330 {
331         unsigned long block, offset;
332         struct buffer_head * bh;
333         struct bfs_dirent * de;
334
335         *res_dir = NULL;
336         if (namelen > BFS_NAMELEN)
337                 return NULL;
338         bh = NULL;
339         block = offset = 0;
340         while (block * BFS_BSIZE + offset < dir->i_size) {
341                 if (!bh) {
342                         bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
343                         if (!bh) {
344                                 block++;
345                                 continue;
346                         }
347                 }
348                 de = (struct bfs_dirent *)(bh->b_data + offset);
349                 offset += BFS_DIRENT_SIZE;
350                 if (le16_to_cpu(de->ino) && bfs_namecmp(namelen, name, de->name)) {
351                         *res_dir = de;
352                         return bh;
353                 }
354                 if (offset < bh->b_size)
355                         continue;
356                 brelse(bh);
357                 bh = NULL;
358                 offset = 0;
359                 block++;
360         }
361         brelse(bh);
362         return NULL;
363 }