Revision a0aa309c39de58b86b704654434431aeb5a8bdf1 authored by Matan Barak on 03 August 2017, 13:06:55 UTC, committed by Doug Ledford on 30 August 2017, 14:30:38 UTC
The ioctl infrastructure treats all user-objects in the same manner. It gets objects ids from the user-space and by using the object type and type attributes mentioned in the object specification, it executes this required method. Passing an object id from the user-space as an attribute is carried out in three stages. The first is carried out before the actual handler and the last is carried out afterwards. The different supported operations are read, write, destroy and create. In the first stage, the former three actions just fetches the object from the repository (by using its id) and locks it. The last action allocates a new uobject. Afterwards, the second stage is carried out when the handler itself carries out the required modification of the object. The last stage is carried out after the handler finishes and commits the result. The former two operations just unlock the object. Destroy calls the "free object" operation, taking into account the object's type and releases the uobject as well. Creation just adds the new uobject to the repository, making the object visible to the application. In order to abstract these details from the ioctl infrastructure layer, we add uverbs_get_uobject_from_context and uverbs_finalize_object functions which corresponds to the first and last stages respectively. Signed-off-by: Matan Barak <matanb@mellanox.com> Reviewed-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
1 parent 82fb342
scatterwalk.c
/*
* Cryptographic API.
*
* Cipher operations.
*
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
* 2002 Adam J. Richter <adam@yggdrasil.com>
* 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <crypto/scatterwalk.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)
{
void *src = out ? buf : sgdata;
void *dst = out ? sgdata : buf;
memcpy(dst, src, nbytes);
}
void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
size_t nbytes, int out)
{
for (;;) {
unsigned int len_this_page = scatterwalk_pagelen(walk);
u8 *vaddr;
if (len_this_page > nbytes)
len_this_page = nbytes;
if (out != 2) {
vaddr = scatterwalk_map(walk);
memcpy_dir(buf, vaddr, len_this_page, out);
scatterwalk_unmap(vaddr);
}
scatterwalk_advance(walk, len_this_page);
if (nbytes == len_this_page)
break;
buf += len_this_page;
nbytes -= len_this_page;
scatterwalk_pagedone(walk, out & 1, 1);
}
}
EXPORT_SYMBOL_GPL(scatterwalk_copychunks);
void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
unsigned int start, unsigned int nbytes, int out)
{
struct scatter_walk walk;
struct scatterlist tmp[2];
if (!nbytes)
return;
sg = scatterwalk_ffwd(tmp, sg, start);
scatterwalk_start(&walk, sg);
scatterwalk_copychunks(buf, &walk, nbytes, out);
scatterwalk_done(&walk, out, 0);
}
EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
struct scatterlist *src,
unsigned int len)
{
for (;;) {
if (!len)
return src;
if (src->length > len)
break;
len -= src->length;
src = sg_next(src);
}
sg_init_table(dst, 2);
sg_set_page(dst, sg_page(src), src->length - len, src->offset + len);
scatterwalk_crypto_chain(dst, sg_next(src), 0, 2);
return dst;
}
EXPORT_SYMBOL_GPL(scatterwalk_ffwd);
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...