Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
[linux-2.6.git] / fs / statfs.c
index 4ef021f..8244924 100644 (file)
 #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>
 
-int vfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+static int flags_by_mnt(int mnt_flags)
 {
-       int retval = -ENODEV;
-
-       if (dentry) {
-               retval = -ENOSYS;
-               if (dentry->d_sb->s_op->statfs) {
-                       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 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;
 }
 
-EXPORT_SYMBOL(vfs_statfs);
+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 vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
+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)
 {
-       struct kstatfs st;
        int retval;
 
-       retval = vfs_statfs(dentry, &st);
+       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);
 
-       if (sizeof(*buf) == sizeof(st))
-               memcpy(buf, &st, sizeof(st));
+int user_statfs(const char __user *pathname, struct kstatfs *st)
+{
+       struct path path;
+       int error = user_path(pathname, &path);
+       if (!error) {
+               error = vfs_statfs(&path, st);
+               path_put(&path);
+       }
+       return error;
+}
+
+int fd_statfs(int fd, struct kstatfs *st)
+{
+       struct file *file = fget(fd);
+       int error = -EBADF;
+       if (file) {
+               error = vfs_statfs(&file->f_path, st);
+               fput(file);
+       }
+       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) &
+               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))
+                       if (st->f_files != -1 &&
+                           (st->f_files & 0xffffffff00000000ULL))
                                return -EOVERFLOW;
-                       if (st.f_ffree != -1 &&
-                           (st.f_ffree & 0xffffffff00000000ULL))
+                       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));
+               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 vfs_statfs64(struct dentry *dentry, struct statfs64 *buf)
+static int do_statfs64(struct kstatfs *st, struct statfs64 __user *p)
 {
-       struct kstatfs st;
-       int retval;
-
-       retval = vfs_statfs(dentry, &st);
-       if (retval)
-               return retval;
-
-       if (sizeof(*buf) == sizeof(st))
-               memcpy(buf, &st, sizeof(st));
+       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;
-               memset(buf->f_spare, 0, sizeof(buf->f_spare));
+               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 path path;
-       int error;
-
-       error = user_path(pathname, &path);
-       if (!error) {
-               struct statfs tmp;
-               error = vfs_statfs_native(path.dentry, &tmp);
-               if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
-                       error = -EFAULT;
-               path_put(&path);
-       }
+       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 path path;
-       long error;
-
+       struct kstatfs st;
+       int error;
        if (sz != sizeof(*buf))
                return -EINVAL;
-       error = user_path(pathname, &path);
-       if (!error) {
-               struct statfs64 tmp;
-               error = vfs_statfs64(path.dentry, &tmp);
-               if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
-                       error = -EFAULT;
-               path_put(&path);
-       }
+       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 file *file;
-       struct statfs tmp;
-       int error;
-
-       error = -EBADF;
-       file = fget(fd);
-       if (!file)
-               goto out;
-       error = vfs_statfs_native(file->f_path.dentry, &tmp);
-       if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
-               error = -EFAULT;
-       fput(file);
-out:
+       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 file *file;
-       struct statfs64 tmp;
+       struct kstatfs st;
        int error;
 
        if (sz != sizeof(*buf))
                return -EINVAL;
 
-       error = -EBADF;
-       file = fget(fd);
-       if (!file)
-               goto out;
-       error = vfs_statfs64(file->f_path.dentry, &tmp);
-       if (!error && copy_to_user(buf, &tmp, sizeof(tmp)))
-               error = -EFAULT;
-       fput(file);
-out:
+       error = fd_statfs(fd, &st);
+       if (!error)
+               error = do_statfs64(&st, buf);
        return error;
 }
 
@@ -183,7 +216,7 @@ SYSCALL_DEFINE2(ustat, unsigned, dev, struct ustat __user *, ubuf)
        if (!s)
                return -EINVAL;
 
-       err = vfs_statfs(s->s_root, &sbuf);
+       err = statfs_by_dentry(s->s_root, &sbuf);
        drop_super(s);
        if (err)
                return err;