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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
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080024static int bfs_add_entry(struct inode *dir, const unsigned char *name,
25 int namelen, int ino);
26static struct buffer_head *bfs_find_entry(struct inode *dir,
27 const unsigned char *name, int namelen,
28 struct bfs_dirent **res_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080030static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir)
Linus Torvalds1da177e2005-04-16 15:20:36 -070031{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080032 struct inode *dir = f->f_path.dentry->d_inode;
33 struct buffer_head *bh;
34 struct bfs_dirent *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 unsigned int offset;
36 int block;
37
38 lock_kernel();
39
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080040 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 unlock_kernel();
45 return -EBADF;
46 }
47
48 while (f->f_pos < dir->i_size) {
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080049 offset = f->f_pos & (BFS_BSIZE - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 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);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080060 if (filldir(dirent, de->name, size, f->f_pos,
61 le16_to_cpu(de->ino),
62 DT_UNKNOWN) < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 brelse(bh);
64 unlock_kernel();
65 return 0;
66 }
67 }
68 offset += BFS_DIRENT_SIZE;
69 f->f_pos += BFS_DIRENT_SIZE;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080070 } while ((offset < BFS_BSIZE) && (f->f_pos < dir->i_size));
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 brelse(bh);
72 }
73
74 unlock_kernel();
75 return 0;
76}
77
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080078const struct file_operations bfs_dir_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 .read = generic_read_dir,
80 .readdir = bfs_readdir,
81 .fsync = file_fsync,
82};
83
84extern void dump_imap(const char *, struct super_block *);
85
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080086static int bfs_create(struct inode *dir, struct dentry *dentry, int mode,
87 struct nameidata *nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -070088{
89 int err;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -080090 struct inode *inode;
91 struct super_block *s = dir->i_sb;
92 struct bfs_sb_info *info = BFS_SB(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 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 }
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800105 set_bit(ino, info->si_imap);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 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;
Theodore Ts'oba52de12006-09-27 01:50:49 -0700110 inode->i_blocks = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 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;
Alexey Dobriyance0fe7e2005-10-04 17:43:06 +0100116 BFS_I(inode)->i_dsk_ino = ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 BFS_I(inode)->i_sblock = 0;
118 BFS_I(inode)->i_eblock = 0;
119 insert_inode_hash(inode);
120 mark_inode_dirty(inode);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800121 dump_imap("create", s);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800123 err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
124 inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 if (err) {
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700126 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 iput(inode);
128 unlock_kernel();
129 return err;
130 }
131 unlock_kernel();
132 d_instantiate(dentry, inode);
133 return 0;
134}
135
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800136static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
137 struct nameidata *nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800139 struct inode *inode = NULL;
140 struct buffer_head *bh;
141 struct bfs_dirent *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
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) {
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700149 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 brelse(bh);
151 inode = iget(dir->i_sb, ino);
152 if (!inode) {
153 unlock_kernel();
154 return ERR_PTR(-EACCES);
155 }
156 }
157 unlock_kernel();
158 d_add(dentry, inode);
159 return NULL;
160}
161
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800162static int bfs_link(struct dentry *old, struct inode *dir,
163 struct dentry *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800165 struct inode *inode = old->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 int err;
167
168 lock_kernel();
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800169 err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
170 inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 if (err) {
172 unlock_kernel();
173 return err;
174 }
Dave Hansend8c76e62006-09-30 23:29:04 -0700175 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 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
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800184static int bfs_unlink(struct inode *dir, struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185{
186 int error = -ENOENT;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800187 struct inode *inode;
188 struct buffer_head *bh;
189 struct bfs_dirent *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
191 inode = dentry->d_inode;
192 lock_kernel();
193 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800194 if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 goto out_brelse;
196
197 if (!inode->i_nlink) {
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800198 printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
199 inode->i_sb->s_id, inode->i_ino,
200 inode->i_nlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 inode->i_ctime = dir->i_ctime;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700208 inode_dec_link_count(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 error = 0;
210
211out_brelse:
212 brelse(bh);
213 unlock_kernel();
214 return error;
215}
216
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800217static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
218 struct inode *new_dir, struct dentry *new_dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800220 struct inode *old_inode, *new_inode;
221 struct buffer_head *old_bh, *new_bh;
222 struct bfs_dirent *old_de, *new_de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 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
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800235 if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 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,
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800251 new_dentry->d_name.len,
252 old_inode->i_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 new_inode->i_ctime = CURRENT_TIME_SEC;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700261 inode_dec_link_count(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 }
263 mark_buffer_dirty(old_bh);
264 error = 0;
265
266end_rename:
267 unlock_kernel();
268 brelse(old_bh);
269 brelse(new_bh);
270 return error;
271}
272
Arjan van de Ven754661f2007-02-12 00:55:38 -0800273const struct inode_operations bfs_dir_inops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 .create = bfs_create,
275 .lookup = bfs_lookup,
276 .link = bfs_link,
277 .unlink = bfs_unlink,
278 .rename = bfs_rename,
279};
280
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800281static int bfs_add_entry(struct inode *dir, const unsigned char *name,
282 int namelen, int ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800284 struct buffer_head *bh;
285 struct bfs_dirent *de;
286 int block, sblock, eblock, off, pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 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;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800298 for (block = sblock; block <= eblock; block++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 bh = sb_bread(dir->i_sb, block);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800300 if (!bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 return -ENOSPC;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800302 for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 de = (struct bfs_dirent *)(bh->b_data + off);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 if (!de->ino) {
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800305 pos = (block - sblock) * BFS_BSIZE + off;
306 if (pos >= dir->i_size) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 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);
Andrew Stribblehillfac92be2005-09-09 13:02:04 -0700312 de->ino = cpu_to_le16((u16)ino);
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800313 for (i = 0; i < BFS_NAMELEN; i++)
314 de->name[i] =
315 (i < namelen) ? name[i] : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 mark_buffer_dirty(bh);
317 brelse(bh);
318 return 0;
319 }
320 }
321 brelse(bh);
322 }
323 return -ENOSPC;
324}
325
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800326static inline int bfs_namecmp(int len, const unsigned char *name,
327 const char *buffer)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800329 if ((len < BFS_NAMELEN) && buffer[len])
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 return 0;
331 return !memcmp(name, buffer, len);
332}
333
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800334static struct buffer_head *bfs_find_entry(struct inode *dir,
335 const unsigned char *name, int namelen,
336 struct bfs_dirent **res_dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337{
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800338 unsigned long block = 0, offset = 0;
339 struct buffer_head *bh = NULL;
340 struct bfs_dirent *de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
342 *res_dir = NULL;
343 if (namelen > BFS_NAMELEN)
344 return NULL;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 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;
Dmitri Vorobievf433dc52007-11-14 16:59:47 -0800356 if (le16_to_cpu(de->ino) &&
357 bfs_namecmp(namelen, name, de->name)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 *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}