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linux/fs/readdir.c
Josef "Jeff" Sipek 0f7fc9e4d0 [PATCH] VFS: change struct file to use struct path 
This patch changes struct file to use struct path instead of having
independent pointers to struct dentry and struct vfsmount, and converts all
users of f_{dentry,vfsmnt} in fs/ to use f_path.{dentry,mnt}.

Additionally, it adds two #define's to make the transition easier for users of
the f_dentry and f_vfsmnt.

Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:41 -08:00

309 lines
6.9 KiB
C
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/*
* linux/fs/readdir.c
*
* Copyright (C) 1995 Linus Torvalds
*/
#include <linux/module.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/file.h>
#include <linux/smp_lock.h>
#include <linux/fs.h>
#include <linux/dirent.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/unistd.h>
#include <asm/uaccess.h>
int vfs_readdir(struct file *file, filldir_t filler, void *buf)
{
struct inode *inode = file->f_path.dentry->d_inode;
int res = -ENOTDIR;
if (!file->f_op || !file->f_op->readdir)
goto out;
res = security_file_permission(file, MAY_READ);
if (res)
goto out;
mutex_lock(&inode->i_mutex);
res = -ENOENT;
if (!IS_DEADDIR(inode)) {
res = file->f_op->readdir(file, buf, filler);
file_accessed(file);
}
mutex_unlock(&inode->i_mutex);
out:
return res;
}
EXPORT_SYMBOL(vfs_readdir);
/*
* Traditional linux readdir() handling..
*
* "count=1" is a special case, meaning that the buffer is one
* dirent-structure in size and that the code can't handle more
* anyway. Thus the special "fillonedir()" function for that
* case (the low-level handlers don't need to care about this).
*/
#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
#define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1))
#ifdef __ARCH_WANT_OLD_READDIR
struct old_linux_dirent {
unsigned long d_ino;
unsigned long d_offset;
unsigned short d_namlen;
char d_name[1];
};
struct readdir_callback {
struct old_linux_dirent __user * dirent;
int result;
};
static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
u64 ino, unsigned int d_type)
{
struct readdir_callback * buf = (struct readdir_callback *) __buf;
struct old_linux_dirent __user * dirent;
unsigned long d_ino;
if (buf->result)
return -EINVAL;
d_ino = ino;
if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
return -EOVERFLOW;
buf->result++;
dirent = buf->dirent;
if (!access_ok(VERIFY_WRITE, dirent,
(unsigned long)(dirent->d_name + namlen + 1) -
(unsigned long)dirent))
goto efault;
if ( __put_user(d_ino, &dirent->d_ino) ||
__put_user(offset, &dirent->d_offset) ||
__put_user(namlen, &dirent->d_namlen) ||
__copy_to_user(dirent->d_name, name, namlen) ||
__put_user(0, dirent->d_name + namlen))
goto efault;
return 0;
efault:
buf->result = -EFAULT;
return -EFAULT;
}
asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count)
{
int error;
struct file * file;
struct readdir_callback buf;
error = -EBADF;
file = fget(fd);
if (!file)
goto out;
buf.result = 0;
buf.dirent = dirent;
error = vfs_readdir(file, fillonedir, &buf);
if (error >= 0)
error = buf.result;
fput(file);
out:
return error;
}
#endif /* __ARCH_WANT_OLD_READDIR */
/*
* New, all-improved, singing, dancing, iBCS2-compliant getdents()
* interface.
*/
struct linux_dirent {
unsigned long d_ino;
unsigned long d_off;
unsigned short d_reclen;
char d_name[1];
};
struct getdents_callback {
struct linux_dirent __user * current_dir;
struct linux_dirent __user * previous;
int count;
int error;
};
static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
u64 ino, unsigned int d_type)
{
struct linux_dirent __user * dirent;
struct getdents_callback * buf = (struct getdents_callback *) __buf;
unsigned long d_ino;
int reclen = ROUND_UP(NAME_OFFSET(dirent) + namlen + 2);
buf->error = -EINVAL; /* only used if we fail.. */
if (reclen > buf->count)
return -EINVAL;
d_ino = ino;
if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
return -EOVERFLOW;
dirent = buf->previous;
if (dirent) {
if (__put_user(offset, &dirent->d_off))
goto efault;
}
dirent = buf->current_dir;
if (__put_user(d_ino, &dirent->d_ino))
goto efault;
if (__put_user(reclen, &dirent->d_reclen))
goto efault;
if (copy_to_user(dirent->d_name, name, namlen))
goto efault;
if (__put_user(0, dirent->d_name + namlen))
goto efault;
if (__put_user(d_type, (char __user *) dirent + reclen - 1))
goto efault;
buf->previous = dirent;
dirent = (void __user *)dirent + reclen;
buf->current_dir = dirent;
buf->count -= reclen;
return 0;
efault:
buf->error = -EFAULT;
return -EFAULT;
}
asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count)
{
struct file * file;
struct linux_dirent __user * lastdirent;
struct getdents_callback buf;
int error;
error = -EFAULT;
if (!access_ok(VERIFY_WRITE, dirent, count))
goto out;
error = -EBADF;
file = fget(fd);
if (!file)
goto out;
buf.current_dir = dirent;
buf.previous = NULL;
buf.count = count;
buf.error = 0;
error = vfs_readdir(file, filldir, &buf);
if (error < 0)
goto out_putf;
error = buf.error;
lastdirent = buf.previous;
if (lastdirent) {
if (put_user(file->f_pos, &lastdirent->d_off))
error = -EFAULT;
else
error = count - buf.count;
}
out_putf:
fput(file);
out:
return error;
}
#define ROUND_UP64(x) (((x)+sizeof(u64)-1) & ~(sizeof(u64)-1))
struct getdents_callback64 {
struct linux_dirent64 __user * current_dir;
struct linux_dirent64 __user * previous;
int count;
int error;
};
static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
u64 ino, unsigned int d_type)
{
struct linux_dirent64 __user *dirent;
struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;
int reclen = ROUND_UP64(NAME_OFFSET(dirent) + namlen + 1);
buf->error = -EINVAL; /* only used if we fail.. */
if (reclen > buf->count)
return -EINVAL;
dirent = buf->previous;
if (dirent) {
if (__put_user(offset, &dirent->d_off))
goto efault;
}
dirent = buf->current_dir;
if (__put_user(ino, &dirent->d_ino))
goto efault;
if (__put_user(0, &dirent->d_off))
goto efault;
if (__put_user(reclen, &dirent->d_reclen))
goto efault;
if (__put_user(d_type, &dirent->d_type))
goto efault;
if (copy_to_user(dirent->d_name, name, namlen))
goto efault;
if (__put_user(0, dirent->d_name + namlen))
goto efault;
buf->previous = dirent;
dirent = (void __user *)dirent + reclen;
buf->current_dir = dirent;
buf->count -= reclen;
return 0;
efault:
buf->error = -EFAULT;
return -EFAULT;
}
asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count)
{
struct file * file;
struct linux_dirent64 __user * lastdirent;
struct getdents_callback64 buf;
int error;
error = -EFAULT;
if (!access_ok(VERIFY_WRITE, dirent, count))
goto out;
error = -EBADF;
file = fget(fd);
if (!file)
goto out;
buf.current_dir = dirent;
buf.previous = NULL;
buf.count = count;
buf.error = 0;
error = vfs_readdir(file, filldir64, &buf);
if (error < 0)
goto out_putf;
error = buf.error;
lastdirent = buf.previous;
if (lastdirent) {
typeof(lastdirent->d_off) d_off = file->f_pos;
error = -EFAULT;
if (__put_user(d_off, &lastdirent->d_off))
goto out_putf;
error = count - buf.count;
}
out_putf:
fput(file);
out:
return error;
}
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