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/*
* linux/fs/stat.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/

#include <linux/module.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/highuid.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/pagemap.h>

#include <asm/uaccess.h>
#include <asm/unistd.h>

void generic_fillattr(struct inode *inode, struct kstat *stat)
{
stat->dev = inode->i_sb->s_dev;
stat->ino = inode->i_ino;
stat->mode = inode->i_mode;
stat->nlink = inode->i_nlink;
stat->uid = inode->i_uid;
stat->gid = inode->i_gid;
stat->rdev = inode->i_rdev;
stat->atime = inode->i_atime;
stat->mtime = inode->i_mtime;
stat->ctime = inode->i_ctime;
stat->size = i_size_read(inode);
stat->blocks = inode->i_blocks;
stat->blksize = (1 << inode->i_blkbits);
}

EXPORT_SYMBOL(generic_fillattr);

int vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = dentry->d_inode;
int retval;

retval = security_inode_getattr(mnt, dentry);
if (retval)
return retval;

if (inode->i_op->getattr)
return inode->i_op->getattr(mnt, dentry, stat);

generic_fillattr(inode, stat);
return 0;
}

EXPORT_SYMBOL(vfs_getattr);

int vfs_fstat(unsigned int fd, struct kstat *stat)
{
struct file *f = fget(fd);
int error = -EBADF;

if (f) {
error = vfs_getattr(f->f_path.mnt, f->f_path.dentry, stat);
fput(f);
}
return error;
}
EXPORT_SYMBOL(vfs_fstat);

int vfs_fstatat(int dfd, char __user *filename, struct kstat *stat, int flag)
{
struct path path;
int error = -EINVAL;
int lookup_flags = 0;

if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
goto out;

if (!(flag & AT_SYMLINK_NOFOLLOW))
lookup_flags |= LOOKUP_FOLLOW;

error = user_path_at(dfd, filename, lookup_flags, &path);
if (error)
goto out;

error = vfs_getattr(path.mnt, path.dentry, stat);
path_put(&path);
out:
return error;
}
EXPORT_SYMBOL(vfs_fstatat);

int vfs_stat(char __user *name, struct kstat *stat)
{
return vfs_fstatat(AT_FDCWD, name, stat, 0);
}
EXPORT_SYMBOL(vfs_stat);

int vfs_lstat(char __user *name, struct kstat *stat)
{
return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
}
EXPORT_SYMBOL(vfs_lstat);


#ifdef __ARCH_WANT_OLD_STAT

/*
* For backward compatibility? Maybe this should be moved
* into arch/i386 instead?
*/
static int cp_old_stat(struct kstat *stat, struct __old_kernel_stat __user * statbuf)
{
static int warncount = 5;
struct __old_kernel_stat tmp;

if (warncount > 0) {
warncount--;
printk(KERN_WARNING "VFS: Warning: %s using old stat() call. Recompile your binary.\n",
current->comm);
} else if (warncount < 0) {
/* it's laughable, but... */
warncount = 0;
}

memset(&tmp, 0, sizeof(struct __old_kernel_stat));
tmp.st_dev = old_encode_dev(stat->dev);
tmp.st_ino = stat->ino;
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
return -EOVERFLOW;
tmp.st_mode = stat->mode;
tmp.st_nlink = stat->nlink;
if (tmp.st_nlink != stat->nlink)
return -EOVERFLOW;
SET_UID(tmp.st_uid, stat->uid);
SET_GID(tmp.st_gid, stat->gid);
tmp.st_rdev = old_encode_dev(stat->rdev);
#if BITS_PER_LONG == 32
if (stat->size > MAX_NON_LFS)
return -EOVERFLOW;
#endif
tmp.st_size = stat->size;
tmp.st_atime = stat->atime.tv_sec;
tmp.st_mtime = stat->mtime.tv_sec;
tmp.st_ctime = stat->ctime.tv_sec;
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}

SYSCALL_DEFINE2(stat, char __user *, filename, struct __old_kernel_stat __user *, statbuf)
{
struct kstat stat;
int error;

error = vfs_stat(filename, &stat);
if (error)
return error;

return cp_old_stat(&stat, statbuf);
}

SYSCALL_DEFINE2(lstat, char __user *, filename, struct __old_kernel_stat __user *, statbuf)
{
struct kstat stat;
int error;

error = vfs_lstat(filename, &stat);
if (error)
return error;

return cp_old_stat(&stat, statbuf);
}

SYSCALL_DEFINE2(fstat, unsigned int, fd, struct __old_kernel_stat __user *, statbuf)
{
struct kstat stat;
int error = vfs_fstat(fd, &stat);

if (!error)
error = cp_old_stat(&stat, statbuf);

return error;
}

#endif /* __ARCH_WANT_OLD_STAT */

static int cp_new_stat(struct kstat *stat, struct stat __user *statbuf)
{
struct stat tmp;

#if BITS_PER_LONG == 32
if (!old_valid_dev(stat->dev) || !old_valid_dev(stat->rdev))
return -EOVERFLOW;
#else
if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
return -EOVERFLOW;
#endif

memset(&tmp, 0, sizeof(tmp));
#if BITS_PER_LONG == 32
tmp.st_dev = old_encode_dev(stat->dev);
#else
tmp.st_dev = new_encode_dev(stat->dev);
#endif
tmp.st_ino = stat->ino;
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
return -EOVERFLOW;
tmp.st_mode = stat->mode;
tmp.st_nlink = stat->nlink;
if (tmp.st_nlink != stat->nlink)
return -EOVERFLOW;
SET_UID(tmp.st_uid, stat->uid);
SET_GID(tmp.st_gid, stat->gid);
#if BITS_PER_LONG == 32
tmp.st_rdev = old_encode_dev(stat->rdev);
#else
tmp.st_rdev = new_encode_dev(stat->rdev);
#endif
#if BITS_PER_LONG == 32
if (stat->size > MAX_NON_LFS)
return -EOVERFLOW;
#endif
tmp.st_size = stat->size;
tmp.st_atime = stat->atime.tv_sec;
tmp.st_mtime = stat->mtime.tv_sec;
tmp.st_ctime = stat->ctime.tv_sec;
#ifdef STAT_HAVE_NSEC
tmp.st_atime_nsec = stat->atime.tv_nsec;
tmp.st_mtime_nsec = stat->mtime.tv_nsec;
tmp.st_ctime_nsec = stat->ctime.tv_nsec;
#endif
tmp.st_blocks = stat->blocks;
tmp.st_blksize = stat->blksize;
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}

SYSCALL_DEFINE2(newstat, char __user *, filename, struct stat __user *, statbuf)
{
struct kstat stat;
int error = vfs_stat(filename, &stat);

if (error)
return error;
return cp_new_stat(&stat, statbuf);
}

SYSCALL_DEFINE2(newlstat, char __user *, filename, struct stat __user *, statbuf)
{
struct kstat stat;
int error;

error = vfs_lstat(filename, &stat);
if (error)
return error;

return cp_new_stat(&stat, statbuf);
}

#if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
SYSCALL_DEFINE4(newfstatat, int, dfd, char __user *, filename,
struct stat __user *, statbuf, int, flag)
{
struct kstat stat;
int error;

error = vfs_fstatat(dfd, filename, &stat, flag);
if (error)
return error;
return cp_new_stat(&stat, statbuf);
}
#endif

SYSCALL_DEFINE2(newfstat, unsigned int, fd, struct stat __user *, statbuf)
{
struct kstat stat;
int error = vfs_fstat(fd, &stat);

if (!error)
error = cp_new_stat(&stat, statbuf);

return error;
}

SYSCALL_DEFINE4(readlinkat, int, dfd, const char __user *, pathname,
char __user *, buf, int, bufsiz)
{
struct path path;
int error;

if (bufsiz <= 0)
return -EINVAL;

error = user_path_at(dfd, pathname, 0, &path);
if (!error) {
struct inode *inode = path.dentry->d_inode;

error = -EINVAL;
if (inode->i_op->readlink) {
error = security_inode_readlink(path.dentry);
if (!error) {
touch_atime(path.mnt, path.dentry);
error = inode->i_op->readlink(path.dentry,
buf, bufsiz);
}
}
path_put(&path);
}
return error;
}

SYSCALL_DEFINE3(readlink, const char __user *, path, char __user *, buf,
int, bufsiz)
{
return sys_readlinkat(AT_FDCWD, path, buf, bufsiz);
}


/* ---------- LFS-64 ----------- */
#ifdef __ARCH_WANT_STAT64

static long cp_new_stat64(struct kstat *stat, struct stat64 __user *statbuf)
{
struct stat64 tmp;

memset(&tmp, 0, sizeof(struct stat64));
#ifdef CONFIG_MIPS
/* mips has weird padding, so we don't get 64 bits there */
if (!new_valid_dev(stat->dev) || !new_valid_dev(stat->rdev))
return -EOVERFLOW;
tmp.st_dev = new_encode_dev(stat->dev);
tmp.st_rdev = new_encode_dev(stat->rdev);
#else
tmp.st_dev = huge_encode_dev(stat->dev);
tmp.st_rdev = huge_encode_dev(stat->rdev);
#endif
tmp.st_ino = stat->ino;
if (sizeof(tmp.st_ino) < sizeof(stat->ino) && tmp.st_ino != stat->ino)
return -EOVERFLOW;
#ifdef STAT64_HAS_BROKEN_ST_INO
tmp.__st_ino = stat->ino;
#endif
tmp.st_mode = stat->mode;
tmp.st_nlink = stat->nlink;
tmp.st_uid = stat->uid;
tmp.st_gid = stat->gid;
tmp.st_atime = stat->atime.tv_sec;
tmp.st_atime_nsec = stat->atime.tv_nsec;
tmp.st_mtime = stat->mtime.tv_sec;
tmp.st_mtime_nsec = stat->mtime.tv_nsec;
tmp.st_ctime = stat->ctime.tv_sec;
tmp.st_ctime_nsec = stat->ctime.tv_nsec;
tmp.st_size = stat->size;
tmp.st_blocks = stat->blocks;
tmp.st_blksize = stat->blksize;
return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
}

SYSCALL_DEFINE2(stat64, char __user *, filename, struct stat64 __user *, statbuf)
{
struct kstat stat;
int error = vfs_stat(filename, &stat);

if (!error)
error = cp_new_stat64(&stat, statbuf);

return error;
}

SYSCALL_DEFINE2(lstat64, char __user *, filename, struct stat64 __user *, statbuf)
{
struct kstat stat;
int error = vfs_lstat(filename, &stat);

if (!error)
error = cp_new_stat64(&stat, statbuf);

return error;
}

SYSCALL_DEFINE2(fstat64, unsigned long, fd, struct stat64 __user *, statbuf)
{
struct kstat stat;
int error = vfs_fstat(fd, &stat);

if (!error)
error = cp_new_stat64(&stat, statbuf);

return error;
}

SYSCALL_DEFINE4(fstatat64, int, dfd, char __user *, filename,
struct stat64 __user *, statbuf, int, flag)
{
struct kstat stat;
int error;

error = vfs_fstatat(dfd, filename, &stat, flag);
if (error)
return error;
return cp_new_stat64(&stat, statbuf);
}
#endif /* __ARCH_WANT_STAT64 */

/* Caller is here responsible for sufficient locking (ie. inode->i_lock) */
void __inode_add_bytes(struct inode *inode, loff_t bytes)
{
inode->i_blocks += bytes >> 9;
bytes &= 511;
inode->i_bytes += bytes;
if (inode->i_bytes >= 512) {
inode->i_blocks++;
inode->i_bytes -= 512;
}
}

void inode_add_bytes(struct inode *inode, loff_t bytes)
{
spin_lock(&inode->i_lock);
__inode_add_bytes(inode, bytes);
spin_unlock(&inode->i_lock);
}

EXPORT_SYMBOL(inode_add_bytes);

void inode_sub_bytes(struct inode *inode, loff_t bytes)
{
spin_lock(&inode->i_lock);
inode->i_blocks -= bytes >> 9;
bytes &= 511;
if (inode->i_bytes < bytes) {
inode->i_blocks--;
inode->i_bytes += 512;
}
inode->i_bytes -= bytes;
spin_unlock(&inode->i_lock);
}

EXPORT_SYMBOL(inode_sub_bytes);

loff_t inode_get_bytes(struct inode *inode)
{
loff_t ret;

spin_lock(&inode->i_lock);
ret = (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
spin_unlock(&inode->i_lock);
return ret;
}

EXPORT_SYMBOL(inode_get_bytes);

void inode_set_bytes(struct inode *inode, loff_t bytes)
{
/* Caller is here responsible for sufficient locking
* (ie. inode->i_lock) */
inode->i_blocks = bytes >> 9;
inode->i_bytes = bytes & 511;
}

EXPORT_SYMBOL(inode_set_bytes);
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