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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 | #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(const 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; unsigned int lookup_flags = LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT; retry: error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); if (!error) { error = vfs_statfs(&path, st); path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; goto retry; } } return error; } int fd_statfs(int fd, struct kstatfs *st) { struct fd f = fdget_raw(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; } |