mirror of
https://github.com/torvalds/linux.git
synced 2024-11-12 07:01:57 +00:00
3cd7967825
Use proper data type to handle get_user_pages_fast error condition. Also do not treat EFAULT error as fatal. Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com> Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
93 lines
2.7 KiB
C
93 lines
2.7 KiB
C
/*
|
|
* Copyright IBM Corporation, 2010
|
|
* Author Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of version 2.1 of the GNU Lesser General Public License
|
|
* as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it would be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
|
*
|
|
*/
|
|
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <net/9p/9p.h>
|
|
#include <net/9p/client.h>
|
|
#include <linux/scatterlist.h>
|
|
#include "trans_common.h"
|
|
|
|
/**
|
|
* p9_release_req_pages - Release pages after the transaction.
|
|
* @*private: PDU's private page of struct trans_rpage_info
|
|
*/
|
|
void
|
|
p9_release_req_pages(struct trans_rpage_info *rpinfo)
|
|
{
|
|
int i = 0;
|
|
|
|
while (rpinfo->rp_data[i] && rpinfo->rp_nr_pages--) {
|
|
put_page(rpinfo->rp_data[i]);
|
|
i++;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(p9_release_req_pages);
|
|
|
|
/**
|
|
* p9_nr_pages - Return number of pages needed to accommodate the payload.
|
|
*/
|
|
int
|
|
p9_nr_pages(struct p9_req_t *req)
|
|
{
|
|
unsigned long start_page, end_page;
|
|
start_page = (unsigned long)req->tc->pubuf >> PAGE_SHIFT;
|
|
end_page = ((unsigned long)req->tc->pubuf + req->tc->pbuf_size +
|
|
PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
return end_page - start_page;
|
|
}
|
|
EXPORT_SYMBOL(p9_nr_pages);
|
|
|
|
/**
|
|
* payload_gup - Translates user buffer into kernel pages and
|
|
* pins them either for read/write through get_user_pages_fast().
|
|
* @req: Request to be sent to server.
|
|
* @pdata_off: data offset into the first page after translation (gup).
|
|
* @pdata_len: Total length of the IO. gup may not return requested # of pages.
|
|
* @nr_pages: number of pages to accommodate the payload
|
|
* @rw: Indicates if the pages are for read or write.
|
|
*/
|
|
int
|
|
p9_payload_gup(struct p9_req_t *req, size_t *pdata_off, int *pdata_len,
|
|
int nr_pages, u8 rw)
|
|
{
|
|
uint32_t first_page_bytes = 0;
|
|
int32_t pdata_mapped_pages;
|
|
struct trans_rpage_info *rpinfo;
|
|
|
|
*pdata_off = (__force size_t)req->tc->pubuf & (PAGE_SIZE-1);
|
|
|
|
if (*pdata_off)
|
|
first_page_bytes = min(((size_t)PAGE_SIZE - *pdata_off),
|
|
req->tc->pbuf_size);
|
|
|
|
rpinfo = req->tc->private;
|
|
pdata_mapped_pages = get_user_pages_fast((unsigned long)req->tc->pubuf,
|
|
nr_pages, rw, &rpinfo->rp_data[0]);
|
|
if (pdata_mapped_pages <= 0)
|
|
return pdata_mapped_pages;
|
|
|
|
rpinfo->rp_nr_pages = pdata_mapped_pages;
|
|
if (*pdata_off) {
|
|
*pdata_len = first_page_bytes;
|
|
*pdata_len += min((req->tc->pbuf_size - *pdata_len),
|
|
((size_t)pdata_mapped_pages - 1) << PAGE_SHIFT);
|
|
} else {
|
|
*pdata_len = min(req->tc->pbuf_size,
|
|
(size_t)pdata_mapped_pages << PAGE_SHIFT);
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(p9_payload_gup);
|