Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
[linux-2.6/sactl.git] / fs / readdir.c
blobb318d9b5af2e9c5d24a325ece38acac3027a2ef8
1 /*
2 * linux/fs/readdir.c
4 * Copyright (C) 1995 Linus Torvalds
5 */
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/time.h>
10 #include <linux/mm.h>
11 #include <linux/errno.h>
12 #include <linux/stat.h>
13 #include <linux/file.h>
14 #include <linux/fs.h>
15 #include <linux/dirent.h>
16 #include <linux/security.h>
17 #include <linux/syscalls.h>
18 #include <linux/unistd.h>
20 #include <asm/uaccess.h>
22 int vfs_readdir(struct file *file, filldir_t filler, void *buf)
24 struct inode *inode = file->f_path.dentry->d_inode;
25 int res = -ENOTDIR;
26 if (!file->f_op || !file->f_op->readdir)
27 goto out;
29 res = security_file_permission(file, MAY_READ);
30 if (res)
31 goto out;
33 res = mutex_lock_killable(&inode->i_mutex);
34 if (res)
35 goto out;
37 res = -ENOENT;
38 if (!IS_DEADDIR(inode)) {
39 res = file->f_op->readdir(file, buf, filler);
40 file_accessed(file);
42 mutex_unlock(&inode->i_mutex);
43 out:
44 return res;
47 EXPORT_SYMBOL(vfs_readdir);
50 * Traditional linux readdir() handling..
52 * "count=1" is a special case, meaning that the buffer is one
53 * dirent-structure in size and that the code can't handle more
54 * anyway. Thus the special "fillonedir()" function for that
55 * case (the low-level handlers don't need to care about this).
57 #define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
59 #ifdef __ARCH_WANT_OLD_READDIR
61 struct old_linux_dirent {
62 unsigned long d_ino;
63 unsigned long d_offset;
64 unsigned short d_namlen;
65 char d_name[1];
68 struct readdir_callback {
69 struct old_linux_dirent __user * dirent;
70 int result;
73 static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
74 u64 ino, unsigned int d_type)
76 struct readdir_callback * buf = (struct readdir_callback *) __buf;
77 struct old_linux_dirent __user * dirent;
78 unsigned long d_ino;
80 if (buf->result)
81 return -EINVAL;
82 d_ino = ino;
83 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
84 buf->result = -EOVERFLOW;
85 return -EOVERFLOW;
87 buf->result++;
88 dirent = buf->dirent;
89 if (!access_ok(VERIFY_WRITE, dirent,
90 (unsigned long)(dirent->d_name + namlen + 1) -
91 (unsigned long)dirent))
92 goto efault;
93 if ( __put_user(d_ino, &dirent->d_ino) ||
94 __put_user(offset, &dirent->d_offset) ||
95 __put_user(namlen, &dirent->d_namlen) ||
96 __copy_to_user(dirent->d_name, name, namlen) ||
97 __put_user(0, dirent->d_name + namlen))
98 goto efault;
99 return 0;
100 efault:
101 buf->result = -EFAULT;
102 return -EFAULT;
105 asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count)
107 int error;
108 struct file * file;
109 struct readdir_callback buf;
111 error = -EBADF;
112 file = fget(fd);
113 if (!file)
114 goto out;
116 buf.result = 0;
117 buf.dirent = dirent;
119 error = vfs_readdir(file, fillonedir, &buf);
120 if (buf.result)
121 error = buf.result;
123 fput(file);
124 out:
125 return error;
128 #endif /* __ARCH_WANT_OLD_READDIR */
131 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
132 * interface.
134 struct linux_dirent {
135 unsigned long d_ino;
136 unsigned long d_off;
137 unsigned short d_reclen;
138 char d_name[1];
141 struct getdents_callback {
142 struct linux_dirent __user * current_dir;
143 struct linux_dirent __user * previous;
144 int count;
145 int error;
148 static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
149 u64 ino, unsigned int d_type)
151 struct linux_dirent __user * dirent;
152 struct getdents_callback * buf = (struct getdents_callback *) __buf;
153 unsigned long d_ino;
154 int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(long));
156 buf->error = -EINVAL; /* only used if we fail.. */
157 if (reclen > buf->count)
158 return -EINVAL;
159 d_ino = ino;
160 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
161 buf->error = -EOVERFLOW;
162 return -EOVERFLOW;
164 dirent = buf->previous;
165 if (dirent) {
166 if (__put_user(offset, &dirent->d_off))
167 goto efault;
169 dirent = buf->current_dir;
170 if (__put_user(d_ino, &dirent->d_ino))
171 goto efault;
172 if (__put_user(reclen, &dirent->d_reclen))
173 goto efault;
174 if (copy_to_user(dirent->d_name, name, namlen))
175 goto efault;
176 if (__put_user(0, dirent->d_name + namlen))
177 goto efault;
178 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
179 goto efault;
180 buf->previous = dirent;
181 dirent = (void __user *)dirent + reclen;
182 buf->current_dir = dirent;
183 buf->count -= reclen;
184 return 0;
185 efault:
186 buf->error = -EFAULT;
187 return -EFAULT;
190 asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count)
192 struct file * file;
193 struct linux_dirent __user * lastdirent;
194 struct getdents_callback buf;
195 int error;
197 error = -EFAULT;
198 if (!access_ok(VERIFY_WRITE, dirent, count))
199 goto out;
201 error = -EBADF;
202 file = fget(fd);
203 if (!file)
204 goto out;
206 buf.current_dir = dirent;
207 buf.previous = NULL;
208 buf.count = count;
209 buf.error = 0;
211 error = vfs_readdir(file, filldir, &buf);
212 if (error >= 0)
213 error = buf.error;
214 lastdirent = buf.previous;
215 if (lastdirent) {
216 if (put_user(file->f_pos, &lastdirent->d_off))
217 error = -EFAULT;
218 else
219 error = count - buf.count;
221 fput(file);
222 out:
223 return error;
226 struct getdents_callback64 {
227 struct linux_dirent64 __user * current_dir;
228 struct linux_dirent64 __user * previous;
229 int count;
230 int error;
233 static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
234 u64 ino, unsigned int d_type)
236 struct linux_dirent64 __user *dirent;
237 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
238 int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64));
240 buf->error = -EINVAL; /* only used if we fail.. */
241 if (reclen > buf->count)
242 return -EINVAL;
243 dirent = buf->previous;
244 if (dirent) {
245 if (__put_user(offset, &dirent->d_off))
246 goto efault;
248 dirent = buf->current_dir;
249 if (__put_user(ino, &dirent->d_ino))
250 goto efault;
251 if (__put_user(0, &dirent->d_off))
252 goto efault;
253 if (__put_user(reclen, &dirent->d_reclen))
254 goto efault;
255 if (__put_user(d_type, &dirent->d_type))
256 goto efault;
257 if (copy_to_user(dirent->d_name, name, namlen))
258 goto efault;
259 if (__put_user(0, dirent->d_name + namlen))
260 goto efault;
261 buf->previous = dirent;
262 dirent = (void __user *)dirent + reclen;
263 buf->current_dir = dirent;
264 buf->count -= reclen;
265 return 0;
266 efault:
267 buf->error = -EFAULT;
268 return -EFAULT;
271 asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count)
273 struct file * file;
274 struct linux_dirent64 __user * lastdirent;
275 struct getdents_callback64 buf;
276 int error;
278 error = -EFAULT;
279 if (!access_ok(VERIFY_WRITE, dirent, count))
280 goto out;
282 error = -EBADF;
283 file = fget(fd);
284 if (!file)
285 goto out;
287 buf.current_dir = dirent;
288 buf.previous = NULL;
289 buf.count = count;
290 buf.error = 0;
292 error = vfs_readdir(file, filldir64, &buf);
293 if (error >= 0)
294 error = buf.error;
295 lastdirent = buf.previous;
296 if (lastdirent) {
297 typeof(lastdirent->d_off) d_off = file->f_pos;
298 if (__put_user(d_off, &lastdirent->d_off))
299 error = -EFAULT;
300 else
301 error = count - buf.count;
303 fput(file);
304 out:
305 return error;