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 iterate_dir(struct file *file, struct dir_context *ctx)
25 struct inode *inode = file_inode(file);
27 if (!file->f_op || (!file->f_op->readdir && !file->f_op->iterate))
30 res = security_file_permission(file, MAY_READ);
34 res = mutex_lock_killable(&inode->i_mutex);
39 if (!IS_DEADDIR(inode)) {
40 if (file->f_op->iterate) {
41 ctx->pos = file->f_pos;
42 res = file->f_op->iterate(file, ctx);
43 file->f_pos = ctx->pos;
45 res = file->f_op->readdir(file, ctx, ctx->actor);
46 ctx->pos = file->f_pos;
50 mutex_unlock(&inode->i_mutex);
54 EXPORT_SYMBOL(iterate_dir);
57 * Traditional linux readdir() handling..
59 * "count=1" is a special case, meaning that the buffer is one
60 * dirent-structure in size and that the code can't handle more
61 * anyway. Thus the special "fillonedir()" function for that
62 * case (the low-level handlers don't need to care about this).
65 #ifdef __ARCH_WANT_OLD_READDIR
67 struct old_linux_dirent {
69 unsigned long d_offset;
70 unsigned short d_namlen;
74 struct readdir_callback {
75 struct dir_context ctx;
76 struct old_linux_dirent __user * dirent;
80 static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
81 u64 ino, unsigned int d_type)
83 struct readdir_callback *buf = (struct readdir_callback *) __buf;
84 struct old_linux_dirent __user * dirent;
90 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
91 buf->result = -EOVERFLOW;
96 if (!access_ok(VERIFY_WRITE, dirent,
97 (unsigned long)(dirent->d_name + namlen + 1) -
98 (unsigned long)dirent))
100 if ( __put_user(d_ino, &dirent->d_ino) ||
101 __put_user(offset, &dirent->d_offset) ||
102 __put_user(namlen, &dirent->d_namlen) ||
103 __copy_to_user(dirent->d_name, name, namlen) ||
104 __put_user(0, dirent->d_name + namlen))
108 buf->result = -EFAULT;
112 SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
113 struct old_linux_dirent __user *, dirent, unsigned int, count)
116 struct fd f = fdget(fd);
117 struct readdir_callback buf;
122 buf.ctx.actor = fillonedir;
126 error = iterate_dir(f.file, &buf.ctx);
134 #endif /* __ARCH_WANT_OLD_READDIR */
137 * New, all-improved, singing, dancing, iBCS2-compliant getdents()
140 struct linux_dirent {
143 unsigned short d_reclen;
147 struct getdents_callback {
148 struct dir_context ctx;
149 struct linux_dirent __user * current_dir;
150 struct linux_dirent __user * previous;
155 static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
156 u64 ino, unsigned int d_type)
158 struct linux_dirent __user * dirent;
159 struct getdents_callback * buf = (struct getdents_callback *) __buf;
161 int reclen = ALIGN(offsetof(struct linux_dirent, d_name) + namlen + 2,
164 buf->error = -EINVAL; /* only used if we fail.. */
165 if (reclen > buf->count)
168 if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
169 buf->error = -EOVERFLOW;
172 dirent = buf->previous;
174 if (__put_user(offset, &dirent->d_off))
177 dirent = buf->current_dir;
178 if (__put_user(d_ino, &dirent->d_ino))
180 if (__put_user(reclen, &dirent->d_reclen))
182 if (copy_to_user(dirent->d_name, name, namlen))
184 if (__put_user(0, dirent->d_name + namlen))
186 if (__put_user(d_type, (char __user *) dirent + reclen - 1))
188 buf->previous = dirent;
189 dirent = (void __user *)dirent + reclen;
190 buf->current_dir = dirent;
191 buf->count -= reclen;
194 buf->error = -EFAULT;
198 SYSCALL_DEFINE3(getdents, unsigned int, fd,
199 struct linux_dirent __user *, dirent, unsigned int, count)
202 struct linux_dirent __user * lastdirent;
203 struct getdents_callback buf;
206 if (!access_ok(VERIFY_WRITE, dirent, count))
213 buf.current_dir = dirent;
217 buf.ctx.actor = filldir;
219 error = iterate_dir(f.file, &buf.ctx);
222 lastdirent = buf.previous;
224 if (put_user(buf.ctx.pos, &lastdirent->d_off))
227 error = count - buf.count;
233 struct getdents_callback64 {
234 struct dir_context ctx;
235 struct linux_dirent64 __user * current_dir;
236 struct linux_dirent64 __user * previous;
241 static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
242 u64 ino, unsigned int d_type)
244 struct linux_dirent64 __user *dirent;
245 struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
246 int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
249 buf->error = -EINVAL; /* only used if we fail.. */
250 if (reclen > buf->count)
252 dirent = buf->previous;
254 if (__put_user(offset, &dirent->d_off))
257 dirent = buf->current_dir;
258 if (__put_user(ino, &dirent->d_ino))
260 if (__put_user(0, &dirent->d_off))
262 if (__put_user(reclen, &dirent->d_reclen))
264 if (__put_user(d_type, &dirent->d_type))
266 if (copy_to_user(dirent->d_name, name, namlen))
268 if (__put_user(0, dirent->d_name + namlen))
270 buf->previous = dirent;
271 dirent = (void __user *)dirent + reclen;
272 buf->current_dir = dirent;
273 buf->count -= reclen;
276 buf->error = -EFAULT;
280 SYSCALL_DEFINE3(getdents64, unsigned int, fd,
281 struct linux_dirent64 __user *, dirent, unsigned int, count)
284 struct linux_dirent64 __user * lastdirent;
285 struct getdents_callback64 buf;
288 if (!access_ok(VERIFY_WRITE, dirent, count))
295 buf.current_dir = dirent;
299 buf.ctx.actor = filldir64;
301 error = iterate_dir(f.file, &buf.ctx);
304 lastdirent = buf.previous;
306 typeof(lastdirent->d_off) d_off = buf.ctx.pos;
307 if (__put_user(d_off, &lastdirent->d_off))
310 error = count - buf.count;