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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - fs/readdir.c
5e69ef533b77bcda920dc79be3de68c8a714d990
4 * Copyright (C) 1995 Linus Torvalds
7 #include <linux/stddef.h>
8 #include <linux/kernel.h>
9 #include <linux/export.h>
10 #include <linux/time.h>
12 #include <linux/errno.h>
13 #include <linux/stat.h>
14 #include <linux/file.h>
16 #include <linux/dirent.h>
17 #include <linux/security.h>
18 #include <linux/syscalls.h>
19 #include <linux/unistd.h>
21 #include <asm/uaccess.h>
23 int vfs_readdir(struct file
*file
, filldir_t filler
, void *buf
)
25 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
27 if (!file
->f_op
|| !file
->f_op
->readdir
)
30 res
= security_file_permission(file
, MAY_READ
);
34 res
= mutex_lock_killable(&inode
->i_mutex
);
39 if (!IS_DEADDIR(inode
)) {
40 res
= file
->f_op
->readdir(file
, buf
, filler
);
43 mutex_unlock(&inode
->i_mutex
);
48 EXPORT_SYMBOL(vfs_readdir
);
51 * Traditional linux readdir() handling..
53 * "count=1" is a special case, meaning that the buffer is one
54 * dirent-structure in size and that the code can't handle more
55 * anyway. Thus the special "fillonedir()" function for that
56 * case (the low-level handlers don't need to care about this).
59 #ifdef __ARCH_WANT_OLD_READDIR
61 struct old_linux_dirent
{
63 unsigned long d_offset
;
64 unsigned short d_namlen
;
68 struct readdir_callback
{
69 struct old_linux_dirent __user
* dirent
;
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
;
83 if (sizeof(d_ino
) < sizeof(ino
) && d_ino
!= ino
) {
84 buf
->result
= -EOVERFLOW
;
89 if (!access_ok(VERIFY_WRITE
, dirent
,
90 (unsigned long)(dirent
->d_name
+ namlen
+ 1) -
91 (unsigned long)dirent
))
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
))
101 buf
->result
= -EFAULT
;
105 SYSCALL_DEFINE3(old_readdir
, unsigned int, fd
,
106 struct old_linux_dirent __user
*, dirent
, unsigned int, count
)
109 struct fd f
= fdget(fd
);
110 struct readdir_callback buf
;
118 error
= vfs_readdir(f
.file
, fillonedir
, &buf
);
126 #endif /* __ARCH_WANT_OLD_READDIR */
129 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
132 struct linux_dirent
{
135 unsigned short d_reclen
;
139 struct getdents_callback
{
140 struct linux_dirent __user
* current_dir
;
141 struct linux_dirent __user
* previous
;
146 static int filldir(void * __buf
, const char * name
, int namlen
, loff_t offset
,
147 u64 ino
, unsigned int d_type
)
149 struct linux_dirent __user
* dirent
;
150 struct getdents_callback
* buf
= (struct getdents_callback
*) __buf
;
152 int reclen
= ALIGN(offsetof(struct linux_dirent
, d_name
) + namlen
+ 2,
155 buf
->error
= -EINVAL
; /* only used if we fail.. */
156 if (reclen
> buf
->count
)
159 if (sizeof(d_ino
) < sizeof(ino
) && d_ino
!= ino
) {
160 buf
->error
= -EOVERFLOW
;
163 dirent
= buf
->previous
;
165 if (__put_user(offset
, &dirent
->d_off
))
168 dirent
= buf
->current_dir
;
169 if (__put_user(d_ino
, &dirent
->d_ino
))
171 if (__put_user(reclen
, &dirent
->d_reclen
))
173 if (copy_to_user(dirent
->d_name
, name
, namlen
))
175 if (__put_user(0, dirent
->d_name
+ namlen
))
177 if (__put_user(d_type
, (char __user
*) dirent
+ reclen
- 1))
179 buf
->previous
= dirent
;
180 dirent
= (void __user
*)dirent
+ reclen
;
181 buf
->current_dir
= dirent
;
182 buf
->count
-= reclen
;
185 buf
->error
= -EFAULT
;
189 SYSCALL_DEFINE3(getdents
, unsigned int, fd
,
190 struct linux_dirent __user
*, dirent
, unsigned int, count
)
193 struct linux_dirent __user
* lastdirent
;
194 struct getdents_callback buf
;
197 if (!access_ok(VERIFY_WRITE
, dirent
, count
))
204 buf
.current_dir
= dirent
;
209 error
= vfs_readdir(f
.file
, filldir
, &buf
);
212 lastdirent
= buf
.previous
;
214 if (put_user(f
.file
->f_pos
, &lastdirent
->d_off
))
217 error
= count
- buf
.count
;
223 struct getdents_callback64
{
224 struct linux_dirent64 __user
* current_dir
;
225 struct linux_dirent64 __user
* previous
;
230 static int filldir64(void * __buf
, const char * name
, int namlen
, loff_t offset
,
231 u64 ino
, unsigned int d_type
)
233 struct linux_dirent64 __user
*dirent
;
234 struct getdents_callback64
* buf
= (struct getdents_callback64
*) __buf
;
235 int reclen
= ALIGN(offsetof(struct linux_dirent64
, d_name
) + namlen
+ 1,
238 buf
->error
= -EINVAL
; /* only used if we fail.. */
239 if (reclen
> buf
->count
)
241 dirent
= buf
->previous
;
243 if (__put_user(offset
, &dirent
->d_off
))
246 dirent
= buf
->current_dir
;
247 if (__put_user(ino
, &dirent
->d_ino
))
249 if (__put_user(0, &dirent
->d_off
))
251 if (__put_user(reclen
, &dirent
->d_reclen
))
253 if (__put_user(d_type
, &dirent
->d_type
))
255 if (copy_to_user(dirent
->d_name
, name
, namlen
))
257 if (__put_user(0, dirent
->d_name
+ namlen
))
259 buf
->previous
= dirent
;
260 dirent
= (void __user
*)dirent
+ reclen
;
261 buf
->current_dir
= dirent
;
262 buf
->count
-= reclen
;
265 buf
->error
= -EFAULT
;
269 SYSCALL_DEFINE3(getdents64
, unsigned int, fd
,
270 struct linux_dirent64 __user
*, dirent
, unsigned int, count
)
273 struct linux_dirent64 __user
* lastdirent
;
274 struct getdents_callback64 buf
;
277 if (!access_ok(VERIFY_WRITE
, dirent
, count
))
284 buf
.current_dir
= dirent
;
289 error
= vfs_readdir(f
.file
, filldir64
, &buf
);
292 lastdirent
= buf
.previous
;
294 typeof(lastdirent
->d_off
) d_off
= f
.file
->f_pos
;
295 if (__put_user(d_off
, &lastdirent
->d_off
))
298 error
= count
- buf
.count
;