[linux.git] / fs / statfs.c

#include <linux/syscalls.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/statfs.h>
#include <linux/security.h>
#include <linux/uaccess.h>

static int flags_by_mnt(int mnt_flags)
{
	int flags = 0;

	if (mnt_flags & MNT_READONLY)
		flags |= ST_RDONLY;
	if (mnt_flags & MNT_NOSUID)
		flags |= ST_NOSUID;
	if (mnt_flags & MNT_NODEV)
		flags |= ST_NODEV;
	if (mnt_flags & MNT_NOEXEC)
		flags |= ST_NOEXEC;
	if (mnt_flags & MNT_NOATIME)
		flags |= ST_NOATIME;
	if (mnt_flags & MNT_NODIRATIME)
		flags |= ST_NODIRATIME;
	if (mnt_flags & MNT_RELATIME)
		flags |= ST_RELATIME;
	return flags;
}

static int flags_by_sb(int s_flags)
{
	int flags = 0;
	if (s_flags & MS_SYNCHRONOUS)
		flags |= ST_SYNCHRONOUS;
	if (s_flags & MS_MANDLOCK)
		flags |= ST_MANDLOCK;
	return flags;
}

static int calculate_f_flags(struct vfsmount *mnt)
{
	return ST_VALID | flags_by_mnt(mnt->mnt_flags) |
		flags_by_sb(mnt->mnt_sb->s_flags);
}

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)
{
	int error;

	error = statfs_by_dentry(path->dentry, buf);
	if (!error)
		buf->f_flags = calculate_f_flags(path->mnt);
	return error;
}
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;
		buf->f_flags = st.f_flags;
		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;
		buf->f_flags = st.f_flags;
		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;
}
Commit	Line	Data
7ed1ee61 AV	1	#include <linux/syscalls.h>
	2	#include <linux/module.h>
	3	#include <linux/fs.h>
	4	#include <linux/file.h>
365b1818	5	#include <linux/mount.h>
7ed1ee61 AV	6	#include <linux/namei.h>
	7	#include <linux/statfs.h>
	8	#include <linux/security.h>
	9	#include <linux/uaccess.h>
	10
365b1818 CH	11	static int flags_by_mnt(int mnt_flags)
	12	{
	13	int flags = 0;
	14
	15	if (mnt_flags & MNT_READONLY)
	16	flags \|= ST_RDONLY;
	17	if (mnt_flags & MNT_NOSUID)
	18	flags \|= ST_NOSUID;
	19	if (mnt_flags & MNT_NODEV)
	20	flags \|= ST_NODEV;
	21	if (mnt_flags & MNT_NOEXEC)
	22	flags \|= ST_NOEXEC;
	23	if (mnt_flags & MNT_NOATIME)
	24	flags \|= ST_NOATIME;
	25	if (mnt_flags & MNT_NODIRATIME)
	26	flags \|= ST_NODIRATIME;
	27	if (mnt_flags & MNT_RELATIME)
	28	flags \|= ST_RELATIME;
	29	return flags;
	30	}
	31
	32	static int flags_by_sb(int s_flags)
	33	{
	34	int flags = 0;
	35	if (s_flags & MS_SYNCHRONOUS)
	36	flags \|= ST_SYNCHRONOUS;
	37	if (s_flags & MS_MANDLOCK)
	38	flags \|= ST_MANDLOCK;
	39	return flags;
	40	}
	41
	42	static int calculate_f_flags(struct vfsmount *mnt)
	43	{
	44	return ST_VALID \| flags_by_mnt(mnt->mnt_flags) \|
	45	flags_by_sb(mnt->mnt_sb->s_flags);
	46	}
	47
ebabe9a9	48	int statfs_by_dentry(struct dentry dentry, struct kstatfs buf)
7ed1ee61	49	{
ebabe9a9 CH	50	int retval;
	51
	52	if (!dentry->d_sb->s_op->statfs)
	53	return -ENOSYS;
	54
	55	memset(buf, 0, sizeof(*buf));
	56	retval = security_sb_statfs(dentry);
	57	if (retval)
	58	return retval;
	59	retval = dentry->d_sb->s_op->statfs(dentry, buf);
	60	if (retval == 0 && buf->f_frsize == 0)
	61	buf->f_frsize = buf->f_bsize;
7ed1ee61 AV	62	return retval;
	63	}
	64
ebabe9a9 CH	65	int vfs_statfs(struct path path, struct kstatfs buf)
ebabe9a9 CH	66	{
365b1818 CH	67	int error;
	68
	69	error = statfs_by_dentry(path->dentry, buf);
	70	if (!error)
	71	buf->f_flags = calculate_f_flags(path->mnt);
	72	return error;
ebabe9a9	73	}
7ed1ee61 AV	74	EXPORT_SYMBOL(vfs_statfs);
7ed1ee61 AV	75
ebabe9a9	76	static int do_statfs_native(struct path path, struct statfs buf)
7ed1ee61 AV	77	{
	78	struct kstatfs st;
	79	int retval;
	80
ebabe9a9	81	retval = vfs_statfs(path, &st);
7ed1ee61 AV	82	if (retval)
	83	return retval;
	84
	85	if (sizeof(*buf) == sizeof(st))
	86	memcpy(buf, &st, sizeof(st));
	87	else {
	88	if (sizeof buf->f_blocks == 4) {
	89	if ((st.f_blocks \| st.f_bfree \| st.f_bavail \|
	90	st.f_bsize \| st.f_frsize) &
	91	0xffffffff00000000ULL)
	92	return -EOVERFLOW;
	93	/*
	94	* f_files and f_ffree may be -1; it's okay to stuff
	95	* that into 32 bits
	96	*/
	97	if (st.f_files != -1 &&
	98	(st.f_files & 0xffffffff00000000ULL))
	99	return -EOVERFLOW;
	100	if (st.f_ffree != -1 &&
	101	(st.f_ffree & 0xffffffff00000000ULL))
	102	return -EOVERFLOW;
	103	}
	104
	105	buf->f_type = st.f_type;
	106	buf->f_bsize = st.f_bsize;
	107	buf->f_blocks = st.f_blocks;
	108	buf->f_bfree = st.f_bfree;
	109	buf->f_bavail = st.f_bavail;
	110	buf->f_files = st.f_files;
	111	buf->f_ffree = st.f_ffree;
	112	buf->f_fsid = st.f_fsid;
	113	buf->f_namelen = st.f_namelen;
	114	buf->f_frsize = st.f_frsize;
365b1818	115	buf->f_flags = st.f_flags;
7ed1ee61 AV	116	memset(buf->f_spare, 0, sizeof(buf->f_spare));
	117	}
	118	return 0;
	119	}
	120
ebabe9a9	121	static int do_statfs64(struct path path, struct statfs64 buf)
7ed1ee61 AV	122	{
	123	struct kstatfs st;
	124	int retval;
	125
ebabe9a9	126	retval = vfs_statfs(path, &st);
7ed1ee61 AV	127	if (retval)
	128	return retval;
	129
	130	if (sizeof(*buf) == sizeof(st))
	131	memcpy(buf, &st, sizeof(st));
	132	else {
	133	buf->f_type = st.f_type;
	134	buf->f_bsize = st.f_bsize;
	135	buf->f_blocks = st.f_blocks;
	136	buf->f_bfree = st.f_bfree;
	137	buf->f_bavail = st.f_bavail;
	138	buf->f_files = st.f_files;
	139	buf->f_ffree = st.f_ffree;
	140	buf->f_fsid = st.f_fsid;
	141	buf->f_namelen = st.f_namelen;
	142	buf->f_frsize = st.f_frsize;
365b1818	143	buf->f_flags = st.f_flags;
7ed1ee61 AV	144	memset(buf->f_spare, 0, sizeof(buf->f_spare));
	145	}
	146	return 0;
	147	}
	148
	149	SYSCALL_DEFINE2(statfs, const char __user , pathname, struct statfs __user , buf)
	150	{
	151	struct path path;
	152	int error;
	153
	154	error = user_path(pathname, &path);
	155	if (!error) {
	156	struct statfs tmp;
ebabe9a9	157	error = do_statfs_native(&path, &tmp);
7ed1ee61 AV	158	if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
	159	error = -EFAULT;
	160	path_put(&path);
	161	}
	162	return error;
	163	}
	164
	165	SYSCALL_DEFINE3(statfs64, const char __user , pathname, size_t, sz, struct statfs64 __user , buf)
	166	{
	167	struct path path;
	168	long error;
	169
	170	if (sz != sizeof(*buf))
	171	return -EINVAL;
	172	error = user_path(pathname, &path);
	173	if (!error) {
	174	struct statfs64 tmp;
ebabe9a9	175	error = do_statfs64(&path, &tmp);
7ed1ee61 AV	176	if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
	177	error = -EFAULT;
	178	path_put(&path);
	179	}
	180	return error;
	181	}
	182
	183	SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf)
	184	{
	185	struct file *file;
	186	struct statfs tmp;
	187	int error;
	188
	189	error = -EBADF;
	190	file = fget(fd);
	191	if (!file)
	192	goto out;
ebabe9a9	193	error = do_statfs_native(&file->f_path, &tmp);
7ed1ee61 AV	194	if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
	195	error = -EFAULT;
	196	fput(file);
	197	out:
	198	return error;
	199	}
	200
	201	SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf)
	202	{
	203	struct file *file;
	204	struct statfs64 tmp;
	205	int error;
	206
	207	if (sz != sizeof(*buf))
	208	return -EINVAL;
	209
	210	error = -EBADF;
	211	file = fget(fd);
	212	if (!file)
	213	goto out;
ebabe9a9	214	error = do_statfs64(&file->f_path, &tmp);
7ed1ee61 AV	215	if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
	216	error = -EFAULT;
	217	fput(file);
	218	out:
	219	return error;
	220	}
	221
	222	SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
	223	{
	224	struct super_block *s;
	225	struct ustat tmp;
	226	struct kstatfs sbuf;
	227	int err;
	228
	229	s = user_get_super(new_decode_dev(dev));
	230	if (!s)
	231	return -EINVAL;
	232
ebabe9a9	233	err = statfs_by_dentry(s->s_root, &sbuf);
7ed1ee61 AV	234	drop_super(s);
	235	if (err)
	236	return err;
	237
	238	memset(&tmp,0,sizeof(struct ustat));
	239	tmp.f_tfree = sbuf.f_bfree;
	240	tmp.f_tinode = sbuf.f_ffree;
	241
	242	return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0;
	243	}