blob: 2a746e688df556519b8d597c999ab2205562ab9f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * fs/bfs/dir.c
3 * BFS directory operations.
4 * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
Andrew Stribblehillfac92be2005-09-09 13:02:04 -07005 * Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 */
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
Andrew Stribblehillfac92be2005-09-09 13:02:04 -070024static int bfs_add_entry(struct inode * dir, const unsigned char * name, int namelen, int ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -070025static struct buffer_head * bfs_find_entry(struct inode * dir,
Andrew Stribblehillfac92be2005-09-09 13:02:04 -070026 const unsigned char * name, int namelen, struct bfs_dirent ** res_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
28static int bfs_readdir(struct file * f, void * dirent, filldir_t filldir)
29{
Josef Sipek61a84242006-12-08 02:36:53 -080030 struct inode * dir = f->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 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);
Andrew Stribblehillfac92be2005-09-09 13:02:04 -070057 if (filldir(dirent, de->name, size, f->f_pos, le16_to_cpu(de->ino), DT_UNKNOWN) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 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
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080073const struct file_operations bfs_dir_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 .read = generic_read_dir,
75 .readdir = bfs_readdir,
76 .fsync = file_fsync,
77};
78
79extern void dump_imap(const char *, struct super_block *);
80
81static 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;
Theodore Ts'oba52de12006-09-27 01:50:49 -0700105 inode->i_blocks = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 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;
Alexey Dobriyance0fe7e2005-10-04 17:43:06 +0100111 BFS_I(inode)->i_dsk_ino = ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 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) {
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700120 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 iput(inode);
122 unlock_kernel();
123 return err;
124 }
125 unlock_kernel();
126 d_instantiate(dentry, inode);
127 return 0;
128}
129
130static struct dentry * bfs_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
131{
132 struct inode * inode = NULL;
133 struct buffer_head * bh;
134 struct bfs_dirent * de;
135
136 if (dentry->d_name.len > BFS_NAMELEN)
137 return ERR_PTR(-ENAMETOOLONG);
138
139 lock_kernel();
140 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
141 if (bh) {
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700142 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 brelse(bh);
144 inode = iget(dir->i_sb, ino);
145 if (!inode) {
146 unlock_kernel();
147 return ERR_PTR(-EACCES);
148 }
149 }
150 unlock_kernel();
151 d_add(dentry, inode);
152 return NULL;
153}
154
155static int bfs_link(struct dentry * old, struct inode * dir, struct dentry * new)
156{
157 struct inode * inode = old->d_inode;
158 int err;
159
160 lock_kernel();
161 err = bfs_add_entry(dir, new->d_name.name, new->d_name.len, inode->i_ino);
162 if (err) {
163 unlock_kernel();
164 return err;
165 }
Dave Hansend8c76e62006-09-30 23:29:04 -0700166 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 inode->i_ctime = CURRENT_TIME_SEC;
168 mark_inode_dirty(inode);
169 atomic_inc(&inode->i_count);
170 d_instantiate(new, inode);
171 unlock_kernel();
172 return 0;
173}
174
175
176static int bfs_unlink(struct inode * dir, struct dentry * dentry)
177{
178 int error = -ENOENT;
179 struct inode * inode;
180 struct buffer_head * bh;
181 struct bfs_dirent * de;
182
183 inode = dentry->d_inode;
184 lock_kernel();
185 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700186 if (!bh || le16_to_cpu(de->ino) != inode->i_ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 goto out_brelse;
188
189 if (!inode->i_nlink) {
190 printf("unlinking non-existent file %s:%lu (nlink=%d)\n", inode->i_sb->s_id,
191 inode->i_ino, inode->i_nlink);
192 inode->i_nlink = 1;
193 }
194 de->ino = 0;
195 mark_buffer_dirty(bh);
196 dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
197 mark_inode_dirty(dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 inode->i_ctime = dir->i_ctime;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700199 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 error = 0;
201
202out_brelse:
203 brelse(bh);
204 unlock_kernel();
205 return error;
206}
207
208static int bfs_rename(struct inode * old_dir, struct dentry * old_dentry,
209 struct inode * new_dir, struct dentry * new_dentry)
210{
211 struct inode * old_inode, * new_inode;
212 struct buffer_head * old_bh, * new_bh;
213 struct bfs_dirent * old_de, * new_de;
214 int error = -ENOENT;
215
216 old_bh = new_bh = NULL;
217 old_inode = old_dentry->d_inode;
218 if (S_ISDIR(old_inode->i_mode))
219 return -EINVAL;
220
221 lock_kernel();
222 old_bh = bfs_find_entry(old_dir,
223 old_dentry->d_name.name,
224 old_dentry->d_name.len, &old_de);
225
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700226 if (!old_bh || le16_to_cpu(old_de->ino) != old_inode->i_ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 goto end_rename;
228
229 error = -EPERM;
230 new_inode = new_dentry->d_inode;
231 new_bh = bfs_find_entry(new_dir,
232 new_dentry->d_name.name,
233 new_dentry->d_name.len, &new_de);
234
235 if (new_bh && !new_inode) {
236 brelse(new_bh);
237 new_bh = NULL;
238 }
239 if (!new_bh) {
240 error = bfs_add_entry(new_dir,
241 new_dentry->d_name.name,
242 new_dentry->d_name.len, old_inode->i_ino);
243 if (error)
244 goto end_rename;
245 }
246 old_de->ino = 0;
247 old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
248 mark_inode_dirty(old_dir);
249 if (new_inode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 new_inode->i_ctime = CURRENT_TIME_SEC;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700251 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 }
253 mark_buffer_dirty(old_bh);
254 error = 0;
255
256end_rename:
257 unlock_kernel();
258 brelse(old_bh);
259 brelse(new_bh);
260 return error;
261}
262
263struct inode_operations bfs_dir_inops = {
264 .create = bfs_create,
265 .lookup = bfs_lookup,
266 .link = bfs_link,
267 .unlink = bfs_unlink,
268 .rename = bfs_rename,
269};
270
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700271static int bfs_add_entry(struct inode * dir, const unsigned char * name, int namelen, int ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272{
273 struct buffer_head * bh;
274 struct bfs_dirent * de;
275 int block, sblock, eblock, off, eoff;
276 int i;
277
278 dprintf("name=%s, namelen=%d\n", name, namelen);
279
280 if (!namelen)
281 return -ENOENT;
282 if (namelen > BFS_NAMELEN)
283 return -ENAMETOOLONG;
284
285 sblock = BFS_I(dir)->i_sblock;
286 eblock = BFS_I(dir)->i_eblock;
287 eoff = dir->i_size % BFS_BSIZE;
288 for (block=sblock; block<=eblock; block++) {
289 bh = sb_bread(dir->i_sb, block);
290 if(!bh)
291 return -ENOSPC;
292 for (off=0; off<BFS_BSIZE; off+=BFS_DIRENT_SIZE) {
293 de = (struct bfs_dirent *)(bh->b_data + off);
294 if (block==eblock && off>=eoff) {
295 /* Do not read/interpret the garbage in the end of eblock. */
296 de->ino = 0;
297 }
298 if (!de->ino) {
299 if ((block-sblock)*BFS_BSIZE + off >= dir->i_size) {
300 dir->i_size += BFS_DIRENT_SIZE;
301 dir->i_ctime = CURRENT_TIME_SEC;
302 }
303 dir->i_mtime = CURRENT_TIME_SEC;
304 mark_inode_dirty(dir);
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700305 de->ino = cpu_to_le16((u16)ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 for (i=0; i<BFS_NAMELEN; i++)
307 de->name[i] = (i < namelen) ? name[i] : 0;
308 mark_buffer_dirty(bh);
309 brelse(bh);
310 return 0;
311 }
312 }
313 brelse(bh);
314 }
315 return -ENOSPC;
316}
317
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700318static inline int bfs_namecmp(int len, const unsigned char * name, const char * buffer)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319{
320 if (len < BFS_NAMELEN && buffer[len])
321 return 0;
322 return !memcmp(name, buffer, len);
323}
324
325static struct buffer_head * bfs_find_entry(struct inode * dir,
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700326 const unsigned char * name, int namelen, struct bfs_dirent ** res_dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327{
328 unsigned long block, offset;
329 struct buffer_head * bh;
330 struct bfs_dirent * de;
331
332 *res_dir = NULL;
333 if (namelen > BFS_NAMELEN)
334 return NULL;
335 bh = NULL;
336 block = offset = 0;
337 while (block * BFS_BSIZE + offset < dir->i_size) {
338 if (!bh) {
339 bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
340 if (!bh) {
341 block++;
342 continue;
343 }
344 }
345 de = (struct bfs_dirent *)(bh->b_data + offset);
346 offset += BFS_DIRENT_SIZE;
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700347 if (le16_to_cpu(de->ino) && bfs_namecmp(namelen, name, de->name)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 *res_dir = de;
349 return bh;
350 }
351 if (offset < bh->b_size)
352 continue;
353 brelse(bh);
354 bh = NULL;
355 offset = 0;
356 block++;
357 }
358 brelse(bh);
359 return NULL;
360}