blob: 9cf04a1189659f07944545097ef806249f40803d [file] [log] [blame]
Al Viro7ed1ee62010-03-23 10:37:36 -04001#include <linux/syscalls.h>
2#include <linux/module.h>
3#include <linux/fs.h>
4#include <linux/file.h>
Christoph Hellwig365b1812010-07-07 18:53:25 +02005#include <linux/mount.h>
Al Viro7ed1ee62010-03-23 10:37:36 -04006#include <linux/namei.h>
7#include <linux/statfs.h>
8#include <linux/security.h>
9#include <linux/uaccess.h>
10
Christoph Hellwig365b1812010-07-07 18:53:25 +020011static 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
32static 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
42static 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
Christoph Hellwigebabe9a2010-07-07 18:53:11 +020048int statfs_by_dentry(struct dentry *dentry, struct kstatfs *buf)
Al Viro7ed1ee62010-03-23 10:37:36 -040049{
Christoph Hellwigebabe9a2010-07-07 18:53:11 +020050 int retval;
Al Viro7ed1ee62010-03-23 10:37:36 -040051
Christoph Hellwigebabe9a2010-07-07 18:53:11 +020052 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;
Al Viro7ed1ee62010-03-23 10:37:36 -040062 return retval;
63}
64
Christoph Hellwigebabe9a2010-07-07 18:53:11 +020065int vfs_statfs(struct path *path, struct kstatfs *buf)
66{
Christoph Hellwig365b1812010-07-07 18:53:25 +020067 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;
Christoph Hellwigebabe9a2010-07-07 18:53:11 +020073}
Al Viro7ed1ee62010-03-23 10:37:36 -040074EXPORT_SYMBOL(vfs_statfs);
75
Al Viroc8b91ac2011-03-12 10:41:39 -050076int user_statfs(const char __user *pathname, struct kstatfs *st)
Al Viro7ed1ee62010-03-23 10:37:36 -040077{
Al Viroc8b91ac2011-03-12 10:41:39 -050078 struct path path;
Dan McGee5c8a0fb2011-11-01 18:23:10 -050079 int error = user_path_at(AT_FDCWD, pathname, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
Al Viroc8b91ac2011-03-12 10:41:39 -050080 if (!error) {
81 error = vfs_statfs(&path, st);
82 path_put(&path);
83 }
84 return error;
85}
Al Viro7ed1ee62010-03-23 10:37:36 -040086
Al Viroc8b91ac2011-03-12 10:41:39 -050087int fd_statfs(int fd, struct kstatfs *st)
88{
89 struct file *file = fget(fd);
90 int error = -EBADF;
91 if (file) {
92 error = vfs_statfs(&file->f_path, st);
93 fput(file);
94 }
95 return error;
96}
Al Viro7ed1ee62010-03-23 10:37:36 -040097
Al Viroc8b91ac2011-03-12 10:41:39 -050098static int do_statfs_native(struct kstatfs *st, struct statfs __user *p)
99{
100 struct statfs buf;
101
102 if (sizeof(buf) == sizeof(*st))
103 memcpy(&buf, st, sizeof(*st));
Al Viro7ed1ee62010-03-23 10:37:36 -0400104 else {
Al Viroc8b91ac2011-03-12 10:41:39 -0500105 if (sizeof buf.f_blocks == 4) {
106 if ((st->f_blocks | st->f_bfree | st->f_bavail |
107 st->f_bsize | st->f_frsize) &
Al Viro7ed1ee62010-03-23 10:37:36 -0400108 0xffffffff00000000ULL)
109 return -EOVERFLOW;
110 /*
111 * f_files and f_ffree may be -1; it's okay to stuff
112 * that into 32 bits
113 */
Al Viroc8b91ac2011-03-12 10:41:39 -0500114 if (st->f_files != -1 &&
115 (st->f_files & 0xffffffff00000000ULL))
Al Viro7ed1ee62010-03-23 10:37:36 -0400116 return -EOVERFLOW;
Al Viroc8b91ac2011-03-12 10:41:39 -0500117 if (st->f_ffree != -1 &&
118 (st->f_ffree & 0xffffffff00000000ULL))
Al Viro7ed1ee62010-03-23 10:37:36 -0400119 return -EOVERFLOW;
120 }
121
Al Viroc8b91ac2011-03-12 10:41:39 -0500122 buf.f_type = st->f_type;
123 buf.f_bsize = st->f_bsize;
124 buf.f_blocks = st->f_blocks;
125 buf.f_bfree = st->f_bfree;
126 buf.f_bavail = st->f_bavail;
127 buf.f_files = st->f_files;
128 buf.f_ffree = st->f_ffree;
129 buf.f_fsid = st->f_fsid;
130 buf.f_namelen = st->f_namelen;
131 buf.f_frsize = st->f_frsize;
132 buf.f_flags = st->f_flags;
133 memset(buf.f_spare, 0, sizeof(buf.f_spare));
Al Viro7ed1ee62010-03-23 10:37:36 -0400134 }
Al Viroc8b91ac2011-03-12 10:41:39 -0500135 if (copy_to_user(p, &buf, sizeof(buf)))
136 return -EFAULT;
Al Viro7ed1ee62010-03-23 10:37:36 -0400137 return 0;
138}
139
Al Viroc8b91ac2011-03-12 10:41:39 -0500140static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p)
Al Viro7ed1ee62010-03-23 10:37:36 -0400141{
Al Viroc8b91ac2011-03-12 10:41:39 -0500142 struct statfs64 buf;
143 if (sizeof(buf) == sizeof(*st))
144 memcpy(&buf, st, sizeof(*st));
Al Viro7ed1ee62010-03-23 10:37:36 -0400145 else {
Al Viroc8b91ac2011-03-12 10:41:39 -0500146 buf.f_type = st->f_type;
147 buf.f_bsize = st->f_bsize;
148 buf.f_blocks = st->f_blocks;
149 buf.f_bfree = st->f_bfree;
150 buf.f_bavail = st->f_bavail;
151 buf.f_files = st->f_files;
152 buf.f_ffree = st->f_ffree;
153 buf.f_fsid = st->f_fsid;
154 buf.f_namelen = st->f_namelen;
155 buf.f_frsize = st->f_frsize;
156 buf.f_flags = st->f_flags;
157 memset(buf.f_spare, 0, sizeof(buf.f_spare));
Al Viro7ed1ee62010-03-23 10:37:36 -0400158 }
Al Viroc8b91ac2011-03-12 10:41:39 -0500159 if (copy_to_user(p, &buf, sizeof(buf)))
160 return -EFAULT;
Al Viro7ed1ee62010-03-23 10:37:36 -0400161 return 0;
162}
163
164SYSCALL_DEFINE2(statfs, const char __user *, pathname, struct statfs __user *, buf)
165{
Al Viroc8b91ac2011-03-12 10:41:39 -0500166 struct kstatfs st;
167 int error = user_statfs(pathname, &st);
168 if (!error)
169 error = do_statfs_native(&st, buf);
Al Viro7ed1ee62010-03-23 10:37:36 -0400170 return error;
171}
172
173SYSCALL_DEFINE3(statfs64, const char __user *, pathname, size_t, sz, struct statfs64 __user *, buf)
174{
Al Viroc8b91ac2011-03-12 10:41:39 -0500175 struct kstatfs st;
176 int error;
Al Viro7ed1ee62010-03-23 10:37:36 -0400177 if (sz != sizeof(*buf))
178 return -EINVAL;
Al Viroc8b91ac2011-03-12 10:41:39 -0500179 error = user_statfs(pathname, &st);
180 if (!error)
181 error = do_statfs64(&st, buf);
Al Viro7ed1ee62010-03-23 10:37:36 -0400182 return error;
183}
184
185SYSCALL_DEFINE2(fstatfs, unsigned int, fd, struct statfs __user *, buf)
186{
Al Viroc8b91ac2011-03-12 10:41:39 -0500187 struct kstatfs st;
188 int error = fd_statfs(fd, &st);
189 if (!error)
190 error = do_statfs_native(&st, buf);
Al Viro7ed1ee62010-03-23 10:37:36 -0400191 return error;
192}
193
194SYSCALL_DEFINE3(fstatfs64, unsigned int, fd, size_t, sz, struct statfs64 __user *, buf)
195{
Al Viroc8b91ac2011-03-12 10:41:39 -0500196 struct kstatfs st;
Al Viro7ed1ee62010-03-23 10:37:36 -0400197 int error;
198
199 if (sz != sizeof(*buf))
200 return -EINVAL;
201
Al Viroc8b91ac2011-03-12 10:41:39 -0500202 error = fd_statfs(fd, &st);
203 if (!error)
204 error = do_statfs64(&st, buf);
Al Viro7ed1ee62010-03-23 10:37:36 -0400205 return error;
206}
207
208SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
209{
210 struct super_block *s;
211 struct ustat tmp;
212 struct kstatfs sbuf;
213 int err;
214
215 s = user_get_super(new_decode_dev(dev));
216 if (!s)
217 return -EINVAL;
218
Christoph Hellwigebabe9a2010-07-07 18:53:11 +0200219 err = statfs_by_dentry(s->s_root, &sbuf);
Al Viro7ed1ee62010-03-23 10:37:36 -0400220 drop_super(s);
221 if (err)
222 return err;
223
224 memset(&tmp,0,sizeof(struct ustat));
225 tmp.f_tfree = sbuf.f_bfree;
226 tmp.f_tinode = sbuf.f_ffree;
227
228 return copy_to_user(ubuf, &tmp, sizeof(struct ustat)) ? -EFAULT : 0;
229}