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#include <linux/syscalls.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/namei.h>
#include <linux/statfs.h>
#include <linux/security.h>
#include <linux/uaccess.h>
int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
{
int retval;
if (!dentry->d_sb->s_op->statfs)
return -ENOSYS;
memset(buf, 0, sizeof(*buf));
retval = security_sb_statfs(dentry);
if (retval)
return retval;
retval = dentry->d_sb->s_op->statfs(dentry, buf);
if (retval == 0 && buf->f_frsize == 0)
buf->f_frsize = buf->f_bsize;
return retval;
}
int vfs_statfs(struct path *path, struct kstatfs *buf)
{
return statfs_by_dentry(path->dentry, buf);
}
EXPORT_SYMBOL(vfs_statfs);
static int do_statfs_native(struct path *path, struct statfs *buf)
{
struct kstatfs st;
int retval;
retval = vfs_statfs(path, &st);
if (retval)
return retval;
if (sizeof(*buf) == sizeof(st))
memcpy(buf, &st, sizeof(st));
else {
if (sizeof buf->f_blocks == 4) {
if ((st.f_blocks | st.f_bfree | st.f_bavail |
st.f_bsize | st.f_frsize) &
0xffffffff00000000ULL)
return -EOVERFLOW;
/*
* f_files and f_ffree may be -1; it's okay to stuff
* that into 32 bits
*/
if (st.f_files != -1 &&
(st.f_files & 0xffffffff00000000ULL))
return -EOVERFLOW;
if (st.f_ffree != -1 &&
(st.f_ffree & 0xffffffff00000000ULL))
return -EOVERFLOW;
}
buf->f_type = st.f_type;
buf->f_bsize = st.f_bsize;
buf->f_blocks = st.f_blocks;
buf->f_bfree = st.f_bfree;
buf->f_bavail = st.f_bavail;
buf->f_files = st.f_files;
buf->f_ffree = st.f_ffree;
buf->f_fsid = st.f_fsid;
buf->f_namelen = st.f_namelen;
buf->f_frsize = st.f_frsize;
memset(buf->f_spare, 0, sizeof(buf->f_spare));
}
return 0;
}
static int do_statfs64(struct path *path, struct statfs64 *buf)
{
struct kstatfs st;
int retval;
retval = vfs_statfs(path, &st);
if (retval)
return retval;
if (sizeof(*buf) == sizeof(st))
memcpy(buf, &st, sizeof(st));
else {
buf->f_type = st.f_type;
buf->f_bsize = st.f_bsize;
buf->f_blocks = st.f_blocks;
buf->f_bfree = st.f_bfree;
buf->f_bavail = st.f_bavail;
buf->f_files = st.f_files;
buf->f_ffree = st.f_ffree;
buf->f_fsid = st.f_fsid;
buf->f_namelen = st.f_namelen;
buf->f_frsize = st.f_frsize;
memset(buf->f_spare, 0, sizeof(buf->f_spare));
}
return 0;
}
SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf)
{
struct path path;
int error;
error = user_path(pathname, &path);
if (!error) {
struct statfs tmp;
error = do_statfs_native(&path, &tmp);
if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
error = -EFAULT;
path_put(&path);
}
return error;
}
SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf)
{
struct path path;
long error;
if (sz != sizeof(*buf))
return -EINVAL;
error = user_path(pathname, &path);
if (!error) {
struct statfs64 tmp;
error = do_statfs64(&path, &tmp);
if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
error = -EFAULT;
path_put(&path);
}
return error;
}
SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf)
{
struct file *file;
struct statfs tmp;
int error;
error = -EBADF;
file = fget(fd);
if (!file)
goto out;
error = do_statfs_native(&file->f_path, &tmp);
if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
error = -EFAULT;
fput(file);
out:
return error;
}
SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf)
{
struct file *file;
struct statfs64 tmp;
int error;
if (sz != sizeof(*buf))
return -EINVAL;
error = -EBADF;
file = fget(fd);
if (!file)
goto out;
error = do_statfs64(&file->f_path, &tmp);
if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
error = -EFAULT;
fput(file);
out:
return error;
}
SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
{
struct super_block *s;
struct ustat tmp;
struct kstatfs sbuf;
int err;
s = user_get_super(new_decode_dev(dev));
if (!s)
return -EINVAL;
err = statfs_by_dentry(s->s_root, &sbuf);
drop_super(s);
if (err)
return err;
memset(&tmp,0,sizeof(struct ustat));
tmp.f_tfree = sbuf.f_bfree;
tmp.f_tinode = sbuf.f_ffree;
return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0;
}
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