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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem
[mirror_ubuntu-bionic-kernel.git] / fs / bfs / dir.c
CommitLineData
1da177e4
LT
1/*
2 * fs/bfs/dir.c
3 * BFS directory operations.
4 * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
fac92bec 5 * Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005
1da177e4
LT
6 */
7
8#include <linux/time.h>
9#include <linux/string.h>
10#include <linux/fs.h>
1da177e4
LT
11#include <linux/buffer_head.h>
12#include <linux/sched.h>
13#include "bfs.h"
14
15#undef DEBUG
16
17#ifdef DEBUG
18#define dprintf(x...) printf(x)
19#else
20#define dprintf(x...)
21#endif
22
f433dc56
DV
23static int bfs_add_entry(struct inode *dir, const unsigned char *name,
24 int namelen, int ino);
25static struct buffer_head *bfs_find_entry(struct inode *dir,
26 const unsigned char *name, int namelen,
27 struct bfs_dirent **res_dir);
1da177e4 28
f433dc56 29static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir)
1da177e4 30{
f433dc56
DV
31 struct inode *dir = f->f_path.dentry->d_inode;
32 struct buffer_head *bh;
33 struct bfs_dirent *de;
3f165e4c 34 struct bfs_sb_info *info = BFS_SB(dir->i_sb);
1da177e4
LT
35 unsigned int offset;
36 int block;
37
3f165e4c 38 mutex_lock(&info->bfs_lock);
1da177e4 39
f433dc56
DV
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);
3f165e4c 44 mutex_unlock(&info->bfs_lock);
1da177e4
LT
45 return -EBADF;
46 }
47
48 while (f->f_pos < dir->i_size) {
f433dc56 49 offset = f->f_pos & (BFS_BSIZE - 1);
1da177e4
LT
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);
f433dc56
DV
60 if (filldir(dirent, de->name, size, f->f_pos,
61 le16_to_cpu(de->ino),
62 DT_UNKNOWN) < 0) {
1da177e4 63 brelse(bh);
3f165e4c 64 mutex_unlock(&info->bfs_lock);
1da177e4
LT
65 return 0;
66 }
67 }
68 offset += BFS_DIRENT_SIZE;
69 f->f_pos += BFS_DIRENT_SIZE;
f433dc56 70 } while ((offset < BFS_BSIZE) && (f->f_pos < dir->i_size));
1da177e4
LT
71 brelse(bh);
72 }
73
3f165e4c 74 mutex_unlock(&info->bfs_lock);
1da177e4
LT
75 return 0;
76}
77
4b6f5d20 78const struct file_operations bfs_dir_operations = {
1da177e4
LT
79 .read = generic_read_dir,
80 .readdir = bfs_readdir,
1b061d92 81 .fsync = generic_file_fsync,
3222a3e5 82 .llseek = generic_file_llseek,
1da177e4
LT
83};
84
85extern void dump_imap(const char *, struct super_block *);
86
f433dc56
DV
87static int bfs_create(struct inode *dir, struct dentry *dentry, int mode,
88 struct nameidata *nd)
1da177e4
LT
89{
90 int err;
f433dc56
DV
91 struct inode *inode;
92 struct super_block *s = dir->i_sb;
93 struct bfs_sb_info *info = BFS_SB(s);
1da177e4
LT
94 unsigned long ino;
95
96 inode = new_inode(s);
97 if (!inode)
98 return -ENOSPC;
3f165e4c 99 mutex_lock(&info->bfs_lock);
69b195be 100 ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
1da177e4 101 if (ino > info->si_lasti) {
3f165e4c 102 mutex_unlock(&info->bfs_lock);
1da177e4
LT
103 iput(inode);
104 return -ENOSPC;
105 }
f433dc56 106 set_bit(ino, info->si_imap);
1da177e4 107 info->si_freei--;
e6ecdc70 108 inode_init_owner(inode, dir, mode);
1da177e4 109 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
ba52de12 110 inode->i_blocks = 0;
1da177e4
LT
111 inode->i_op = &bfs_file_inops;
112 inode->i_fop = &bfs_file_operations;
113 inode->i_mapping->a_ops = &bfs_aops;
1da177e4 114 inode->i_ino = ino;
ce0fe7e7 115 BFS_I(inode)->i_dsk_ino = ino;
1da177e4
LT
116 BFS_I(inode)->i_sblock = 0;
117 BFS_I(inode)->i_eblock = 0;
118 insert_inode_hash(inode);
119 mark_inode_dirty(inode);
f433dc56 120 dump_imap("create", s);
1da177e4 121
f433dc56
DV
122 err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
123 inode->i_ino);
1da177e4 124 if (err) {
9a53c3a7 125 inode_dec_link_count(inode);
3f165e4c 126 mutex_unlock(&info->bfs_lock);
1558182f 127 iput(inode);
1da177e4
LT
128 return err;
129 }
3f165e4c 130 mutex_unlock(&info->bfs_lock);
1da177e4
LT
131 d_instantiate(dentry, inode);
132 return 0;
133}
134
f433dc56
DV
135static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
136 struct nameidata *nd)
1da177e4 137{
f433dc56
DV
138 struct inode *inode = NULL;
139 struct buffer_head *bh;
140 struct bfs_dirent *de;
3f165e4c 141 struct bfs_sb_info *info = BFS_SB(dir->i_sb);
1da177e4
LT
142
143 if (dentry->d_name.len > BFS_NAMELEN)
144 return ERR_PTR(-ENAMETOOLONG);
145
3f165e4c 146 mutex_lock(&info->bfs_lock);
1da177e4
LT
147 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
148 if (bh) {
fac92bec 149 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
1da177e4 150 brelse(bh);
e33ab086
DH
151 inode = bfs_iget(dir->i_sb, ino);
152 if (IS_ERR(inode)) {
3f165e4c 153 mutex_unlock(&info->bfs_lock);
e33ab086 154 return ERR_CAST(inode);
1da177e4
LT
155 }
156 }
3f165e4c 157 mutex_unlock(&info->bfs_lock);
1da177e4
LT
158 d_add(dentry, inode);
159 return NULL;
160}
161
f433dc56
DV
162static int bfs_link(struct dentry *old, struct inode *dir,
163 struct dentry *new)
1da177e4 164{
f433dc56 165 struct inode *inode = old->d_inode;
3f165e4c 166 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
1da177e4
LT
167 int err;
168
3f165e4c 169 mutex_lock(&info->bfs_lock);
f433dc56
DV
170 err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
171 inode->i_ino);
1da177e4 172 if (err) {
3f165e4c 173 mutex_unlock(&info->bfs_lock);
1da177e4
LT
174 return err;
175 }
d8c76e6f 176 inc_nlink(inode);
1da177e4
LT
177 inode->i_ctime = CURRENT_TIME_SEC;
178 mark_inode_dirty(inode);
7de9c6ee 179 ihold(inode);
1da177e4 180 d_instantiate(new, inode);
3f165e4c 181 mutex_unlock(&info->bfs_lock);
1da177e4
LT
182 return 0;
183}
184
f433dc56 185static int bfs_unlink(struct inode *dir, struct dentry *dentry)
1da177e4
LT
186{
187 int error = -ENOENT;
3f165e4c 188 struct inode *inode = dentry->d_inode;
f433dc56
DV
189 struct buffer_head *bh;
190 struct bfs_dirent *de;
3f165e4c 191 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
1da177e4 192
3f165e4c 193 mutex_lock(&info->bfs_lock);
1da177e4 194 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
f433dc56 195 if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
1da177e4
LT
196 goto out_brelse;
197
198 if (!inode->i_nlink) {
f433dc56
DV
199 printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
200 inode->i_sb->s_id, inode->i_ino,
201 inode->i_nlink);
1da177e4
LT
202 inode->i_nlink = 1;
203 }
204 de->ino = 0;
4427f0c3 205 mark_buffer_dirty_inode(bh, dir);
1da177e4
LT
206 dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
207 mark_inode_dirty(dir);
1da177e4 208 inode->i_ctime = dir->i_ctime;
9a53c3a7 209 inode_dec_link_count(inode);
1da177e4
LT
210 error = 0;
211
212out_brelse:
213 brelse(bh);
3f165e4c 214 mutex_unlock(&info->bfs_lock);
1da177e4
LT
215 return error;
216}
217
f433dc56
DV
218static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
219 struct inode *new_dir, struct dentry *new_dentry)
1da177e4 220{
f433dc56
DV
221 struct inode *old_inode, *new_inode;
222 struct buffer_head *old_bh, *new_bh;
223 struct bfs_dirent *old_de, *new_de;
3f165e4c 224 struct bfs_sb_info *info;
1da177e4
LT
225 int error = -ENOENT;
226
e4eaac06
SW
227 if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
228 dentry_unhash(new_dentry);
229
1da177e4
LT
230 old_bh = new_bh = NULL;
231 old_inode = old_dentry->d_inode;
232 if (S_ISDIR(old_inode->i_mode))
233 return -EINVAL;
234
3f165e4c
DV
235 info = BFS_SB(old_inode->i_sb);
236
237 mutex_lock(&info->bfs_lock);
1da177e4
LT
238 old_bh = bfs_find_entry(old_dir,
239 old_dentry->d_name.name,
240 old_dentry->d_name.len, &old_de);
241
f433dc56 242 if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
1da177e4
LT
243 goto end_rename;
244
245 error = -EPERM;
246 new_inode = new_dentry->d_inode;
247 new_bh = bfs_find_entry(new_dir,
248 new_dentry->d_name.name,
249 new_dentry->d_name.len, &new_de);
250
251 if (new_bh && !new_inode) {
252 brelse(new_bh);
253 new_bh = NULL;
254 }
255 if (!new_bh) {
256 error = bfs_add_entry(new_dir,
257 new_dentry->d_name.name,
f433dc56
DV
258 new_dentry->d_name.len,
259 old_inode->i_ino);
1da177e4
LT
260 if (error)
261 goto end_rename;
262 }
263 old_de->ino = 0;
264 old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
265 mark_inode_dirty(old_dir);
266 if (new_inode) {
1da177e4 267 new_inode->i_ctime = CURRENT_TIME_SEC;
9a53c3a7 268 inode_dec_link_count(new_inode);
1da177e4 269 }
4427f0c3 270 mark_buffer_dirty_inode(old_bh, old_dir);
1da177e4
LT
271 error = 0;
272
273end_rename:
3f165e4c 274 mutex_unlock(&info->bfs_lock);
1da177e4
LT
275 brelse(old_bh);
276 brelse(new_bh);
277 return error;
278}
279
754661f1 280const struct inode_operations bfs_dir_inops = {
1da177e4
LT
281 .create = bfs_create,
282 .lookup = bfs_lookup,
283 .link = bfs_link,
284 .unlink = bfs_unlink,
285 .rename = bfs_rename,
286};
287
f433dc56
DV
288static int bfs_add_entry(struct inode *dir, const unsigned char *name,
289 int namelen, int ino)
1da177e4 290{
f433dc56
DV
291 struct buffer_head *bh;
292 struct bfs_dirent *de;
293 int block, sblock, eblock, off, pos;
1da177e4
LT
294 int i;
295
296 dprintf("name=%s, namelen=%d\n", name, namelen);
297
298 if (!namelen)
299 return -ENOENT;
300 if (namelen > BFS_NAMELEN)
301 return -ENAMETOOLONG;
302
303 sblock = BFS_I(dir)->i_sblock;
304 eblock = BFS_I(dir)->i_eblock;
f433dc56 305 for (block = sblock; block <= eblock; block++) {
1da177e4 306 bh = sb_bread(dir->i_sb, block);
f433dc56 307 if (!bh)
1da177e4 308 return -ENOSPC;
f433dc56 309 for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
1da177e4 310 de = (struct bfs_dirent *)(bh->b_data + off);
1da177e4 311 if (!de->ino) {
f433dc56
DV
312 pos = (block - sblock) * BFS_BSIZE + off;
313 if (pos >= dir->i_size) {
1da177e4
LT
314 dir->i_size += BFS_DIRENT_SIZE;
315 dir->i_ctime = CURRENT_TIME_SEC;
316 }
317 dir->i_mtime = CURRENT_TIME_SEC;
318 mark_inode_dirty(dir);
fac92bec 319 de->ino = cpu_to_le16((u16)ino);
f433dc56
DV
320 for (i = 0; i < BFS_NAMELEN; i++)
321 de->name[i] =
322 (i < namelen) ? name[i] : 0;
4427f0c3 323 mark_buffer_dirty_inode(bh, dir);
1da177e4
LT
324 brelse(bh);
325 return 0;
326 }
327 }
328 brelse(bh);
329 }
330 return -ENOSPC;
331}
332
f433dc56
DV
333static inline int bfs_namecmp(int len, const unsigned char *name,
334 const char *buffer)
1da177e4 335{
f433dc56 336 if ((len < BFS_NAMELEN) && buffer[len])
1da177e4
LT
337 return 0;
338 return !memcmp(name, buffer, len);
339}
340
f433dc56
DV
341static struct buffer_head *bfs_find_entry(struct inode *dir,
342 const unsigned char *name, int namelen,
343 struct bfs_dirent **res_dir)
1da177e4 344{
f433dc56
DV
345 unsigned long block = 0, offset = 0;
346 struct buffer_head *bh = NULL;
347 struct bfs_dirent *de;
1da177e4
LT
348
349 *res_dir = NULL;
350 if (namelen > BFS_NAMELEN)
351 return NULL;
f433dc56 352
1da177e4
LT
353 while (block * BFS_BSIZE + offset < dir->i_size) {
354 if (!bh) {
355 bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
356 if (!bh) {
357 block++;
358 continue;
359 }
360 }
361 de = (struct bfs_dirent *)(bh->b_data + offset);
362 offset += BFS_DIRENT_SIZE;
f433dc56
DV
363 if (le16_to_cpu(de->ino) &&
364 bfs_namecmp(namelen, name, de->name)) {
1da177e4
LT
365 *res_dir = de;
366 return bh;
367 }
368 if (offset < bh->b_size)
369 continue;
370 brelse(bh);
371 bh = NULL;
372 offset = 0;
373 block++;
374 }
375 brelse(bh);
376 return NULL;
377}