Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fs/bfs/dir.c
4 * BFS directory operations.
5 * Copyright (C) 1999-2018 Tigran Aivazian <aivazian.tigran@gmail.com>
6 * Made endianness-clean by Andrew Stribblehill <ads@wompom.org> 2005
7 */
8
9#include <linux/time.h>
10#include <linux/string.h>
11#include <linux/fs.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
24static int bfs_add_entry(struct inode *dir, const struct qstr *child, int ino);
25static struct buffer_head *bfs_find_entry(struct inode *dir,
26 const struct qstr *child,
27 struct bfs_dirent **res_dir);
28
29static int bfs_readdir(struct file *f, struct dir_context *ctx)
30{
31 struct inode *dir = file_inode(f);
32 struct buffer_head *bh;
33 struct bfs_dirent *de;
34 unsigned int offset;
35 int block;
36
37 if (ctx->pos & (BFS_DIRENT_SIZE - 1)) {
38 printf("Bad f_pos=%08lx for %s:%08lx\n",
39 (unsigned long)ctx->pos,
40 dir->i_sb->s_id, dir->i_ino);
41 return -EINVAL;
42 }
43
44 while (ctx->pos < dir->i_size) {
45 offset = ctx->pos & (BFS_BSIZE - 1);
46 block = BFS_I(dir)->i_sblock + (ctx->pos >> BFS_BSIZE_BITS);
47 bh = sb_bread(dir->i_sb, block);
48 if (!bh) {
49 ctx->pos += BFS_BSIZE - offset;
50 continue;
51 }
52 do {
53 de = (struct bfs_dirent *)(bh->b_data + offset);
54 if (de->ino) {
55 int size = strnlen(de->name, BFS_NAMELEN);
56 if (!dir_emit(ctx, de->name, size,
57 le16_to_cpu(de->ino),
58 DT_UNKNOWN)) {
59 brelse(bh);
60 return 0;
61 }
62 }
63 offset += BFS_DIRENT_SIZE;
64 ctx->pos += BFS_DIRENT_SIZE;
65 } while ((offset < BFS_BSIZE) && (ctx->pos < dir->i_size));
66 brelse(bh);
67 }
68 return 0;
69}
70
71const struct file_operations bfs_dir_operations = {
72 .read = generic_read_dir,
73 .iterate_shared = bfs_readdir,
74 .fsync = generic_file_fsync,
75 .llseek = generic_file_llseek,
76};
77
78static int bfs_create(struct mnt_idmap *idmap, struct inode *dir,
79 struct dentry *dentry, umode_t mode, bool excl)
80{
81 int err;
82 struct inode *inode;
83 struct super_block *s = dir->i_sb;
84 struct bfs_sb_info *info = BFS_SB(s);
85 unsigned long ino;
86
87 inode = new_inode(s);
88 if (!inode)
89 return -ENOMEM;
90 mutex_lock(&info->bfs_lock);
91 ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
92 if (ino > info->si_lasti) {
93 mutex_unlock(&info->bfs_lock);
94 iput(inode);
95 return -ENOSPC;
96 }
97 set_bit(ino, info->si_imap);
98 info->si_freei--;
99 inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
100 simple_inode_init_ts(inode);
101 inode->i_blocks = 0;
102 inode->i_op = &bfs_file_inops;
103 inode->i_fop = &bfs_file_operations;
104 inode->i_mapping->a_ops = &bfs_aops;
105 inode->i_ino = ino;
106 BFS_I(inode)->i_dsk_ino = ino;
107 BFS_I(inode)->i_sblock = 0;
108 BFS_I(inode)->i_eblock = 0;
109 insert_inode_hash(inode);
110 mark_inode_dirty(inode);
111 bfs_dump_imap("create", s);
112
113 err = bfs_add_entry(dir, &dentry->d_name, inode->i_ino);
114 if (err) {
115 inode_dec_link_count(inode);
116 mutex_unlock(&info->bfs_lock);
117 iput(inode);
118 return err;
119 }
120 mutex_unlock(&info->bfs_lock);
121 d_instantiate(dentry, inode);
122 return 0;
123}
124
125static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
126 unsigned int flags)
127{
128 struct inode *inode = NULL;
129 struct buffer_head *bh;
130 struct bfs_dirent *de;
131 struct bfs_sb_info *info = BFS_SB(dir->i_sb);
132
133 if (dentry->d_name.len > BFS_NAMELEN)
134 return ERR_PTR(-ENAMETOOLONG);
135
136 mutex_lock(&info->bfs_lock);
137 bh = bfs_find_entry(dir, &dentry->d_name, &de);
138 if (bh) {
139 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
140 brelse(bh);
141 inode = bfs_iget(dir->i_sb, ino);
142 }
143 mutex_unlock(&info->bfs_lock);
144 return d_splice_alias(inode, dentry);
145}
146
147static int bfs_link(struct dentry *old, struct inode *dir,
148 struct dentry *new)
149{
150 struct inode *inode = d_inode(old);
151 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
152 int err;
153
154 mutex_lock(&info->bfs_lock);
155 err = bfs_add_entry(dir, &new->d_name, inode->i_ino);
156 if (err) {
157 mutex_unlock(&info->bfs_lock);
158 return err;
159 }
160 inc_nlink(inode);
161 inode_set_ctime_current(inode);
162 mark_inode_dirty(inode);
163 ihold(inode);
164 d_instantiate(new, inode);
165 mutex_unlock(&info->bfs_lock);
166 return 0;
167}
168
169static int bfs_unlink(struct inode *dir, struct dentry *dentry)
170{
171 int error = -ENOENT;
172 struct inode *inode = d_inode(dentry);
173 struct buffer_head *bh;
174 struct bfs_dirent *de;
175 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
176
177 mutex_lock(&info->bfs_lock);
178 bh = bfs_find_entry(dir, &dentry->d_name, &de);
179 if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
180 goto out_brelse;
181
182 if (!inode->i_nlink) {
183 printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
184 inode->i_sb->s_id, inode->i_ino,
185 inode->i_nlink);
186 set_nlink(inode, 1);
187 }
188 de->ino = 0;
189 mark_buffer_dirty_inode(bh, dir);
190 inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
191 mark_inode_dirty(dir);
192 inode_set_ctime_to_ts(inode, inode_get_ctime(dir));
193 inode_dec_link_count(inode);
194 error = 0;
195
196out_brelse:
197 brelse(bh);
198 mutex_unlock(&info->bfs_lock);
199 return error;
200}
201
202static int bfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
203 struct dentry *old_dentry, struct inode *new_dir,
204 struct dentry *new_dentry, unsigned int flags)
205{
206 struct inode *old_inode, *new_inode;
207 struct buffer_head *old_bh, *new_bh;
208 struct bfs_dirent *old_de, *new_de;
209 struct bfs_sb_info *info;
210 int error = -ENOENT;
211
212 if (flags & ~RENAME_NOREPLACE)
213 return -EINVAL;
214
215 old_bh = new_bh = NULL;
216 old_inode = d_inode(old_dentry);
217 if (S_ISDIR(old_inode->i_mode))
218 return -EINVAL;
219
220 info = BFS_SB(old_inode->i_sb);
221
222 mutex_lock(&info->bfs_lock);
223 old_bh = bfs_find_entry(old_dir, &old_dentry->d_name, &old_de);
224
225 if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
226 goto end_rename;
227
228 error = -EPERM;
229 new_inode = d_inode(new_dentry);
230 new_bh = bfs_find_entry(new_dir, &new_dentry->d_name, &new_de);
231
232 if (new_bh && !new_inode) {
233 brelse(new_bh);
234 new_bh = NULL;
235 }
236 if (!new_bh) {
237 error = bfs_add_entry(new_dir, &new_dentry->d_name,
238 old_inode->i_ino);
239 if (error)
240 goto end_rename;
241 }
242 old_de->ino = 0;
243 inode_set_mtime_to_ts(old_dir, inode_set_ctime_current(old_dir));
244 mark_inode_dirty(old_dir);
245 if (new_inode) {
246 inode_set_ctime_current(new_inode);
247 inode_dec_link_count(new_inode);
248 }
249 mark_buffer_dirty_inode(old_bh, old_dir);
250 error = 0;
251
252end_rename:
253 mutex_unlock(&info->bfs_lock);
254 brelse(old_bh);
255 brelse(new_bh);
256 return error;
257}
258
259const struct inode_operations bfs_dir_inops = {
260 .create = bfs_create,
261 .lookup = bfs_lookup,
262 .link = bfs_link,
263 .unlink = bfs_unlink,
264 .rename = bfs_rename,
265};
266
267static int bfs_add_entry(struct inode *dir, const struct qstr *child, int ino)
268{
269 const unsigned char *name = child->name;
270 int namelen = child->len;
271 struct buffer_head *bh;
272 struct bfs_dirent *de;
273 int block, sblock, eblock, off, pos;
274 int i;
275
276 dprintf("name=%s, namelen=%d\n", name, namelen);
277
278 sblock = BFS_I(dir)->i_sblock;
279 eblock = BFS_I(dir)->i_eblock;
280 for (block = sblock; block <= eblock; block++) {
281 bh = sb_bread(dir->i_sb, block);
282 if (!bh)
283 return -EIO;
284 for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
285 de = (struct bfs_dirent *)(bh->b_data + off);
286 if (!de->ino) {
287 pos = (block - sblock) * BFS_BSIZE + off;
288 if (pos >= dir->i_size) {
289 dir->i_size += BFS_DIRENT_SIZE;
290 inode_set_ctime_current(dir);
291 }
292 inode_set_mtime_to_ts(dir,
293 inode_set_ctime_current(dir));
294 mark_inode_dirty(dir);
295 de->ino = cpu_to_le16((u16)ino);
296 for (i = 0; i < BFS_NAMELEN; i++)
297 de->name[i] =
298 (i < namelen) ? name[i] : 0;
299 mark_buffer_dirty_inode(bh, dir);
300 brelse(bh);
301 return 0;
302 }
303 }
304 brelse(bh);
305 }
306 return -ENOSPC;
307}
308
309static inline int bfs_namecmp(int len, const unsigned char *name,
310 const char *buffer)
311{
312 if ((len < BFS_NAMELEN) && buffer[len])
313 return 0;
314 return !memcmp(name, buffer, len);
315}
316
317static struct buffer_head *bfs_find_entry(struct inode *dir,
318 const struct qstr *child,
319 struct bfs_dirent **res_dir)
320{
321 unsigned long block = 0, offset = 0;
322 struct buffer_head *bh = NULL;
323 struct bfs_dirent *de;
324 const unsigned char *name = child->name;
325 int namelen = child->len;
326
327 *res_dir = NULL;
328 if (namelen > BFS_NAMELEN)
329 return NULL;
330
331 while (block * BFS_BSIZE + offset < dir->i_size) {
332 if (!bh) {
333 bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
334 if (!bh) {
335 block++;
336 continue;
337 }
338 }
339 de = (struct bfs_dirent *)(bh->b_data + offset);
340 offset += BFS_DIRENT_SIZE;
341 if (le16_to_cpu(de->ino) &&
342 bfs_namecmp(namelen, name, de->name)) {
343 *res_dir = de;
344 return bh;
345 }
346 if (offset < bh->b_size)
347 continue;
348 brelse(bh);
349 bh = NULL;
350 offset = 0;
351 block++;
352 }
353 brelse(bh);
354 return NULL;
355}
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/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
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);
28
29static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir)
30{
31 struct inode *dir = f->f_path.dentry->d_inode;
32 struct buffer_head *bh;
33 struct bfs_dirent *de;
34 struct bfs_sb_info *info = BFS_SB(dir->i_sb);
35 unsigned int offset;
36 int block;
37
38 mutex_lock(&info->bfs_lock);
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 mutex_unlock(&info->bfs_lock);
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 mutex_unlock(&info->bfs_lock);
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 mutex_unlock(&info->bfs_lock);
75 return 0;
76}
77
78const struct file_operations bfs_dir_operations = {
79 .read = generic_read_dir,
80 .readdir = bfs_readdir,
81 .fsync = generic_file_fsync,
82 .llseek = generic_file_llseek,
83};
84
85extern void dump_imap(const char *, struct super_block *);
86
87static int bfs_create(struct inode *dir, struct dentry *dentry, int mode,
88 struct nameidata *nd)
89{
90 int err;
91 struct inode *inode;
92 struct super_block *s = dir->i_sb;
93 struct bfs_sb_info *info = BFS_SB(s);
94 unsigned long ino;
95
96 inode = new_inode(s);
97 if (!inode)
98 return -ENOSPC;
99 mutex_lock(&info->bfs_lock);
100 ino = find_first_zero_bit(info->si_imap, info->si_lasti + 1);
101 if (ino > info->si_lasti) {
102 mutex_unlock(&info->bfs_lock);
103 iput(inode);
104 return -ENOSPC;
105 }
106 set_bit(ino, info->si_imap);
107 info->si_freei--;
108 inode_init_owner(inode, dir, mode);
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_ino = ino;
115 BFS_I(inode)->i_dsk_ino = ino;
116 BFS_I(inode)->i_sblock = 0;
117 BFS_I(inode)->i_eblock = 0;
118 insert_inode_hash(inode);
119 mark_inode_dirty(inode);
120 dump_imap("create", s);
121
122 err = bfs_add_entry(dir, dentry->d_name.name, dentry->d_name.len,
123 inode->i_ino);
124 if (err) {
125 inode_dec_link_count(inode);
126 mutex_unlock(&info->bfs_lock);
127 iput(inode);
128 return err;
129 }
130 mutex_unlock(&info->bfs_lock);
131 d_instantiate(dentry, inode);
132 return 0;
133}
134
135static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
136 struct nameidata *nd)
137{
138 struct inode *inode = NULL;
139 struct buffer_head *bh;
140 struct bfs_dirent *de;
141 struct bfs_sb_info *info = BFS_SB(dir->i_sb);
142
143 if (dentry->d_name.len > BFS_NAMELEN)
144 return ERR_PTR(-ENAMETOOLONG);
145
146 mutex_lock(&info->bfs_lock);
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 mutex_unlock(&info->bfs_lock);
154 return ERR_CAST(inode);
155 }
156 }
157 mutex_unlock(&info->bfs_lock);
158 d_add(dentry, inode);
159 return NULL;
160}
161
162static int bfs_link(struct dentry *old, struct inode *dir,
163 struct dentry *new)
164{
165 struct inode *inode = old->d_inode;
166 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
167 int err;
168
169 mutex_lock(&info->bfs_lock);
170 err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
171 inode->i_ino);
172 if (err) {
173 mutex_unlock(&info->bfs_lock);
174 return err;
175 }
176 inc_nlink(inode);
177 inode->i_ctime = CURRENT_TIME_SEC;
178 mark_inode_dirty(inode);
179 ihold(inode);
180 d_instantiate(new, inode);
181 mutex_unlock(&info->bfs_lock);
182 return 0;
183}
184
185static int bfs_unlink(struct inode *dir, struct dentry *dentry)
186{
187 int error = -ENOENT;
188 struct inode *inode = dentry->d_inode;
189 struct buffer_head *bh;
190 struct bfs_dirent *de;
191 struct bfs_sb_info *info = BFS_SB(inode->i_sb);
192
193 mutex_lock(&info->bfs_lock);
194 bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
195 if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
196 goto out_brelse;
197
198 if (!inode->i_nlink) {
199 printf("unlinking non-existent file %s:%lu (nlink=%d)\n",
200 inode->i_sb->s_id, inode->i_ino,
201 inode->i_nlink);
202 inode->i_nlink = 1;
203 }
204 de->ino = 0;
205 mark_buffer_dirty_inode(bh, dir);
206 dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC;
207 mark_inode_dirty(dir);
208 inode->i_ctime = dir->i_ctime;
209 inode_dec_link_count(inode);
210 error = 0;
211
212out_brelse:
213 brelse(bh);
214 mutex_unlock(&info->bfs_lock);
215 return error;
216}
217
218static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
219 struct inode *new_dir, struct dentry *new_dentry)
220{
221 struct inode *old_inode, *new_inode;
222 struct buffer_head *old_bh, *new_bh;
223 struct bfs_dirent *old_de, *new_de;
224 struct bfs_sb_info *info;
225 int error = -ENOENT;
226
227 old_bh = new_bh = NULL;
228 old_inode = old_dentry->d_inode;
229 if (S_ISDIR(old_inode->i_mode))
230 return -EINVAL;
231
232 info = BFS_SB(old_inode->i_sb);
233
234 mutex_lock(&info->bfs_lock);
235 old_bh = bfs_find_entry(old_dir,
236 old_dentry->d_name.name,
237 old_dentry->d_name.len, &old_de);
238
239 if (!old_bh || (le16_to_cpu(old_de->ino) != old_inode->i_ino))
240 goto end_rename;
241
242 error = -EPERM;
243 new_inode = new_dentry->d_inode;
244 new_bh = bfs_find_entry(new_dir,
245 new_dentry->d_name.name,
246 new_dentry->d_name.len, &new_de);
247
248 if (new_bh && !new_inode) {
249 brelse(new_bh);
250 new_bh = NULL;
251 }
252 if (!new_bh) {
253 error = bfs_add_entry(new_dir,
254 new_dentry->d_name.name,
255 new_dentry->d_name.len,
256 old_inode->i_ino);
257 if (error)
258 goto end_rename;
259 }
260 old_de->ino = 0;
261 old_dir->i_ctime = old_dir->i_mtime = CURRENT_TIME_SEC;
262 mark_inode_dirty(old_dir);
263 if (new_inode) {
264 new_inode->i_ctime = CURRENT_TIME_SEC;
265 inode_dec_link_count(new_inode);
266 }
267 mark_buffer_dirty_inode(old_bh, old_dir);
268 error = 0;
269
270end_rename:
271 mutex_unlock(&info->bfs_lock);
272 brelse(old_bh);
273 brelse(new_bh);
274 return error;
275}
276
277const struct inode_operations bfs_dir_inops = {
278 .create = bfs_create,
279 .lookup = bfs_lookup,
280 .link = bfs_link,
281 .unlink = bfs_unlink,
282 .rename = bfs_rename,
283};
284
285static int bfs_add_entry(struct inode *dir, const unsigned char *name,
286 int namelen, int ino)
287{
288 struct buffer_head *bh;
289 struct bfs_dirent *de;
290 int block, sblock, eblock, off, pos;
291 int i;
292
293 dprintf("name=%s, namelen=%d\n", name, namelen);
294
295 if (!namelen)
296 return -ENOENT;
297 if (namelen > BFS_NAMELEN)
298 return -ENAMETOOLONG;
299
300 sblock = BFS_I(dir)->i_sblock;
301 eblock = BFS_I(dir)->i_eblock;
302 for (block = sblock; block <= eblock; block++) {
303 bh = sb_bread(dir->i_sb, block);
304 if (!bh)
305 return -ENOSPC;
306 for (off = 0; off < BFS_BSIZE; off += BFS_DIRENT_SIZE) {
307 de = (struct bfs_dirent *)(bh->b_data + off);
308 if (!de->ino) {
309 pos = (block - sblock) * BFS_BSIZE + off;
310 if (pos >= dir->i_size) {
311 dir->i_size += BFS_DIRENT_SIZE;
312 dir->i_ctime = CURRENT_TIME_SEC;
313 }
314 dir->i_mtime = CURRENT_TIME_SEC;
315 mark_inode_dirty(dir);
316 de->ino = cpu_to_le16((u16)ino);
317 for (i = 0; i < BFS_NAMELEN; i++)
318 de->name[i] =
319 (i < namelen) ? name[i] : 0;
320 mark_buffer_dirty_inode(bh, dir);
321 brelse(bh);
322 return 0;
323 }
324 }
325 brelse(bh);
326 }
327 return -ENOSPC;
328}
329
330static inline int bfs_namecmp(int len, const unsigned char *name,
331 const char *buffer)
332{
333 if ((len < BFS_NAMELEN) && buffer[len])
334 return 0;
335 return !memcmp(name, buffer, len);
336}
337
338static struct buffer_head *bfs_find_entry(struct inode *dir,
339 const unsigned char *name, int namelen,
340 struct bfs_dirent **res_dir)
341{
342 unsigned long block = 0, offset = 0;
343 struct buffer_head *bh = NULL;
344 struct bfs_dirent *de;
345
346 *res_dir = NULL;
347 if (namelen > BFS_NAMELEN)
348 return NULL;
349
350 while (block * BFS_BSIZE + offset < dir->i_size) {
351 if (!bh) {
352 bh = sb_bread(dir->i_sb, BFS_I(dir)->i_sblock + block);
353 if (!bh) {
354 block++;
355 continue;
356 }
357 }
358 de = (struct bfs_dirent *)(bh->b_data + offset);
359 offset += BFS_DIRENT_SIZE;
360 if (le16_to_cpu(de->ino) &&
361 bfs_namecmp(namelen, name, de->name)) {
362 *res_dir = de;
363 return bh;
364 }
365 if (offset < bh->b_size)
366 continue;
367 brelse(bh);
368 bh = NULL;
369 offset = 0;
370 block++;
371 }
372 brelse(bh);
373 return NULL;
374}