From: Mikulas Patocka Date: Fri, 1 Mar 2013 22:45:49 +0000 (+0000) Subject: dm ioctl: optimize functions without variable params X-Git-Tag: v3.9-rc1~19^2~11 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=02cde50b7ea74557d32ff778c73809322445ccd2;p=pandora-kernel.git dm ioctl: optimize functions without variable params Device-mapper ioctls receive and send data in a buffer supplied by userspace. The buffer has two parts. The first part contains a 'struct dm_ioctl' and has a fixed size. The second part depends on the ioctl and has a variable size. This patch recognises the specific ioctls that do not use the variable part of the buffer and skips allocating memory for it. In particular, when a device is suspended and a resume ioctl is sent, this now avoid memory allocation completely. The variable "struct dm_ioctl tmp" is moved from the function copy_params to its caller ctl_ioctl and renamed to param_kernel. It is used directly when the ioctl function doesn't need any arguments. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- Reading git-diff-tree failed