goto fput_in;
if (!(out.file->f_mode & FMODE_WRITE))
goto fput_out;
- retval = -EINVAL;
in_inode = file_inode(in.file);
out_inode = file_inode(out.file);
out_pos = out.file->f_pos;
}
EXPORT_SYMBOL(vfs_dedupe_file_range_compare);
+/* Check whether we are allowed to dedupe the destination file */
+static bool allow_file_dedupe(struct file *file)
+{
+ if (capable(CAP_SYS_ADMIN))
+ return true;
+ if (file->f_mode & FMODE_WRITE)
+ return true;
+ if (uid_eq(current_fsuid(), file_inode(file)->i_uid))
+ return true;
+ if (!inode_permission(file_inode(file), MAY_WRITE))
+ return true;
+ return false;
+}
+
int vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
struct file *dst_file, loff_t dst_pos, u64 len)
{
if (ret < 0)
goto out_drop_write;
- ret = -EINVAL;
- if (!(capable(CAP_SYS_ADMIN) || (dst_file->f_mode & FMODE_WRITE)))
+ ret = -EPERM;
+ if (!allow_file_dedupe(dst_file))
goto out_drop_write;
ret = -EXDEV;