Take statfs variants to fs/statfs.c

[cascardo/linux.git] / fs / statfs.c

diff --git a/fs/statfs.c b/fs/statfs.c
new file mode 100644 (file)
index 0000000..4ef021f
--- /dev/null
+++ b/fs/statfs.c
@@ -0,0 +1,196 @@
+#include <linux/syscalls.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/file.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)
+{
+       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;
+}
+
+EXPORT_SYMBOL(vfs_statfs);
+
+static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
+{
+       struct kstatfs st;
+       int retval;
+
+       retval = vfs_statfs(dentry, &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;
+               memset(buf->f_spare, 0, sizeof(buf->f_spare));
+       }
+       return 0;
+}
+
+static int vfs_statfs64(struct dentry *dentry, struct statfs64 *buf)
+{
+       struct kstatfs st;
+       int retval;
+
+       retval = vfs_statfs(dentry, &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;
+               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 = vfs_statfs_native(path.dentry, &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 = vfs_statfs64(path.dentry, &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 = vfs_statfs_native(file->f_path.dentry, &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 = vfs_statfs64(file->f_path.dentry, &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 = vfs_statfs(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;
+}