[linux.git] / fs / statfs.c

#include <linux/syscalls.h>
#include <linux/export.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>
#include "internal.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);
}

static 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);

int user_statfs(const char __user *pathname, struct kstatfs *st)
{
	struct path path;
	int error = user_path_at(AT_FDCWD, pathname, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
	if (!error) {
		error = vfs_statfs(&path, st);
		path_put(&path);
	}
	return error;
}

int fd_statfs(int fd, struct kstatfs *st)
{
	struct fd f = fdget(fd);
	int error = -EBADF;
	if (f.file) {
		error = vfs_statfs(&f.file->f_path, st);
		fdput(f);
	}
	return error;
}

static int do_statfs_native(struct kstatfs *st, struct statfs __user *p)
{
	struct statfs buf;

	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));
	}
	if (copy_to_user(p, &buf, sizeof(buf)))
		return -EFAULT;
	return 0;
}

static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p)
{
	struct statfs64 buf;
	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));
	}
	if (copy_to_user(p, &buf, sizeof(buf)))
		return -EFAULT;
	return 0;
}

SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf)
{
	struct kstatfs st;
	int error = user_statfs(pathname, &st);
	if (!error)
		error = do_statfs_native(&st, buf);
	return error;
}

SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf)
{
	struct kstatfs st;
	int error;
	if (sz != sizeof(*buf))
		return -EINVAL;
	error = user_statfs(pathname, &st);
	if (!error)
		error = do_statfs64(&st, buf);
	return error;
}

SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf)
{
	struct kstatfs st;
	int error = fd_statfs(fd, &st);
	if (!error)
		error = do_statfs_native(&st, buf);
	return error;
}

SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf)
{
	struct kstatfs st;
	int error;

	if (sz != sizeof(*buf))
		return -EINVAL;

	error = fd_statfs(fd, &st);
	if (!error)
		error = do_statfs64(&st, buf);
	return error;
}

int vfs_ustat(dev_t dev, struct kstatfs *sbuf)
{
	struct super_block *s = user_get_super(dev);
	int err;
	if (!s)
		return -EINVAL;

	err = statfs_by_dentry(s->s_root, sbuf);
	drop_super(s);
	return err;
}

SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
{
	struct ustat tmp;
	struct kstatfs sbuf;
	int err = vfs_ustat(new_decode_dev(dev), &sbuf);
	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	1	#include <linux/syscalls.h>
630d9c47	2	#include <linux/export.h>
7ed1ee61 AV	3	#include <linux/fs.h>
7ed1ee61 AV	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>
cf31e70d	10	#include "internal.h"
7ed1ee61	11
365b1818 CH	12	static int flags_by_mnt(int mnt_flags)
	13	{
	14	int flags = 0;
	15
	16	if (mnt_flags & MNT_READONLY)
	17	flags \|= ST_RDONLY;
	18	if (mnt_flags & MNT_NOSUID)
	19	flags \|= ST_NOSUID;
	20	if (mnt_flags & MNT_NODEV)
	21	flags \|= ST_NODEV;
	22	if (mnt_flags & MNT_NOEXEC)
	23	flags \|= ST_NOEXEC;
	24	if (mnt_flags & MNT_NOATIME)
	25	flags \|= ST_NOATIME;
	26	if (mnt_flags & MNT_NODIRATIME)
	27	flags \|= ST_NODIRATIME;
	28	if (mnt_flags & MNT_RELATIME)
	29	flags \|= ST_RELATIME;
	30	return flags;
	31	}
	32
	33	static int flags_by_sb(int s_flags)
	34	{
	35	int flags = 0;
	36	if (s_flags & MS_SYNCHRONOUS)
	37	flags \|= ST_SYNCHRONOUS;
	38	if (s_flags & MS_MANDLOCK)
	39	flags \|= ST_MANDLOCK;
	40	return flags;
	41	}
	42
	43	static int calculate_f_flags(struct vfsmount *mnt)
	44	{
	45	return ST_VALID \| flags_by_mnt(mnt->mnt_flags) \|
	46	flags_by_sb(mnt->mnt_sb->s_flags);
	47	}
	48
cf31e70d	49	static int statfs_by_dentry(struct dentry dentry, struct kstatfs buf)
7ed1ee61	50	{
ebabe9a9 CH	51	int retval;
	52
	53	if (!dentry->d_sb->s_op->statfs)
	54	return -ENOSYS;
	55
	56	memset(buf, 0, sizeof(*buf));
	57	retval = security_sb_statfs(dentry);
	58	if (retval)
	59	return retval;
	60	retval = dentry->d_sb->s_op->statfs(dentry, buf);
	61	if (retval == 0 && buf->f_frsize == 0)
	62	buf->f_frsize = buf->f_bsize;
7ed1ee61 AV	63	return retval;
	64	}
	65
ebabe9a9 CH	66	int vfs_statfs(struct path path, struct kstatfs buf)
ebabe9a9 CH	67	{
365b1818 CH	68	int error;
	69
	70	error = statfs_by_dentry(path->dentry, buf);
	71	if (!error)
	72	buf->f_flags = calculate_f_flags(path->mnt);
	73	return error;
ebabe9a9	74	}
7ed1ee61 AV	75	EXPORT_SYMBOL(vfs_statfs);
7ed1ee61 AV	76
c8b91acc	77	int user_statfs(const char __user pathname, struct kstatfs st)
7ed1ee61	78	{
c8b91acc	79	struct path path;
5c8a0fbb	80	int error = user_path_at(AT_FDCWD, pathname, LOOKUP_FOLLOW\|LOOKUP_AUTOMOUNT, &path);
c8b91acc AV	81	if (!error) {
	82	error = vfs_statfs(&path, st);
	83	path_put(&path);
	84	}
	85	return error;
	86	}
7ed1ee61	87
c8b91acc AV	88	int fd_statfs(int fd, struct kstatfs *st)
c8b91acc AV	89	{
2903ff01	90	struct fd f = fdget(fd);
c8b91acc	91	int error = -EBADF;
2903ff01 AV	92	if (f.file) {
	93	error = vfs_statfs(&f.file->f_path, st);
	94	fdput(f);
c8b91acc AV	95	}
	96	return error;
	97	}
7ed1ee61	98
c8b91acc AV	99	static int do_statfs_native(struct kstatfs st, struct statfs __user p)
	100	{
	101	struct statfs buf;
	102
	103	if (sizeof(buf) == sizeof(*st))
	104	memcpy(&buf, st, sizeof(*st));
7ed1ee61	105	else {
c8b91acc AV	106	if (sizeof buf.f_blocks == 4) {
	107	if ((st->f_blocks \| st->f_bfree \| st->f_bavail \|
	108	st->f_bsize \| st->f_frsize) &
7ed1ee61 AV	109	0xffffffff00000000ULL)
	110	return -EOVERFLOW;
	111	/*
	112	* f_files and f_ffree may be -1; it's okay to stuff
	113	* that into 32 bits
	114	*/
c8b91acc AV	115	if (st->f_files != -1 &&
c8b91acc AV	116	(st->f_files & 0xffffffff00000000ULL))
7ed1ee61	117	return -EOVERFLOW;
c8b91acc AV	118	if (st->f_ffree != -1 &&
c8b91acc AV	119	(st->f_ffree & 0xffffffff00000000ULL))
7ed1ee61 AV	120	return -EOVERFLOW;
	121	}
	122
c8b91acc AV	123	buf.f_type = st->f_type;
	124	buf.f_bsize = st->f_bsize;
	125	buf.f_blocks = st->f_blocks;
	126	buf.f_bfree = st->f_bfree;
	127	buf.f_bavail = st->f_bavail;
	128	buf.f_files = st->f_files;
	129	buf.f_ffree = st->f_ffree;
	130	buf.f_fsid = st->f_fsid;
	131	buf.f_namelen = st->f_namelen;
	132	buf.f_frsize = st->f_frsize;
	133	buf.f_flags = st->f_flags;
	134	memset(buf.f_spare, 0, sizeof(buf.f_spare));
7ed1ee61	135	}
c8b91acc AV	136	if (copy_to_user(p, &buf, sizeof(buf)))
c8b91acc AV	137	return -EFAULT;
7ed1ee61 AV	138	return 0;
	139	}
	140
c8b91acc	141	static int do_statfs64(struct kstatfs st, struct statfs64 __user p)
7ed1ee61	142	{
c8b91acc AV	143	struct statfs64 buf;
	144	if (sizeof(buf) == sizeof(*st))
	145	memcpy(&buf, st, sizeof(*st));
7ed1ee61	146	else {
c8b91acc AV	147	buf.f_type = st->f_type;
	148	buf.f_bsize = st->f_bsize;
	149	buf.f_blocks = st->f_blocks;
	150	buf.f_bfree = st->f_bfree;
	151	buf.f_bavail = st->f_bavail;
	152	buf.f_files = st->f_files;
	153	buf.f_ffree = st->f_ffree;
	154	buf.f_fsid = st->f_fsid;
	155	buf.f_namelen = st->f_namelen;
	156	buf.f_frsize = st->f_frsize;
	157	buf.f_flags = st->f_flags;
	158	memset(buf.f_spare, 0, sizeof(buf.f_spare));
7ed1ee61	159	}
c8b91acc AV	160	if (copy_to_user(p, &buf, sizeof(buf)))
c8b91acc AV	161	return -EFAULT;
7ed1ee61 AV	162	return 0;
	163	}
	164
	165	SYSCALL_DEFINE2(statfs, const char __user , pathname, struct statfs __user , buf)
	166	{
c8b91acc AV	167	struct kstatfs st;
	168	int error = user_statfs(pathname, &st);
	169	if (!error)
	170	error = do_statfs_native(&st, buf);
7ed1ee61 AV	171	return error;
	172	}
	173
	174	SYSCALL_DEFINE3(statfs64, const char __user , pathname, size_t, sz, struct statfs64 __user , buf)
	175	{
c8b91acc AV	176	struct kstatfs st;
c8b91acc AV	177	int error;
7ed1ee61 AV	178	if (sz != sizeof(*buf))
7ed1ee61 AV	179	return -EINVAL;
c8b91acc AV	180	error = user_statfs(pathname, &st);
	181	if (!error)
	182	error = do_statfs64(&st, buf);
7ed1ee61 AV	183	return error;
	184	}
	185
	186	SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf)
	187	{
c8b91acc AV	188	struct kstatfs st;
	189	int error = fd_statfs(fd, &st);
	190	if (!error)
	191	error = do_statfs_native(&st, buf);
7ed1ee61 AV	192	return error;
	193	}
	194
	195	SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf)
	196	{
c8b91acc	197	struct kstatfs st;
7ed1ee61 AV	198	int error;
	199
	200	if (sz != sizeof(*buf))
	201	return -EINVAL;
	202
c8b91acc AV	203	error = fd_statfs(fd, &st);
	204	if (!error)
	205	error = do_statfs64(&st, buf);
7ed1ee61 AV	206	return error;
	207	}
	208
cf31e70d	209	int vfs_ustat(dev_t dev, struct kstatfs *sbuf)
7ed1ee61	210	{
cf31e70d	211	struct super_block *s = user_get_super(dev);
7ed1ee61	212	int err;
7ed1ee61 AV	213	if (!s)
	214	return -EINVAL;
	215
cf31e70d	216	err = statfs_by_dentry(s->s_root, sbuf);
7ed1ee61	217	drop_super(s);
cf31e70d AV	218	return err;
	219	}
	220
	221	SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
	222	{
	223	struct ustat tmp;
	224	struct kstatfs sbuf;
	225	int err = vfs_ustat(new_decode_dev(dev), &sbuf);
7ed1ee61 AV	226	if (err)
	227	return err;
	228
	229	memset(&tmp,0,sizeof(struct ustat));
	230	tmp.f_tfree = sbuf.f_bfree;
	231	tmp.f_tinode = sbuf.f_ffree;
	232
	233	return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0;
	234	}