From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755231Ab0CWQYp (ORCPT ); Tue, 23 Mar 2010 12:24:45 -0400 Received: from mail.pripojeni.net ([217.66.174.14]:51603 "EHLO mail.jetsystems.cz" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755022Ab0CWQXS (ORCPT ); Tue, 23 Mar 2010 12:23:18 -0400 From: Jiri Slaby To: jirislaby@gmail.com Cc: pavel@ucw.cz, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Jiri Slaby , Nigel Cunningham , "Rafael J. Wysocki" Subject: [RFC 11/15] PM / Hibernate: add chunk i/o support Date: Tue, 23 Mar 2010 17:17:39 +0100 Message-Id: <1269361063-3341-11-git-send-email-jslaby@suse.cz> X-Mailer: git-send-email 1.7.0.2 In-Reply-To: <1269361063-3341-1-git-send-email-jslaby@suse.cz> References: <1269361063-3341-1-git-send-email-jslaby@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Chunk support is useful when not writing whole pages at once. It takes care of joining the buffers into the pages and writing at once when needed. In the end when pages are compressed they use this interface as well (because they are indeed shorter than PAGE_SIZE). Signed-off-by: Jiri Slaby Cc: Nigel Cunningham Cc: "Rafael J. Wysocki" --- kernel/power/block_io.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++ kernel/power/power.h | 6 +++ 2 files changed, 87 insertions(+), 0 deletions(-) diff --git a/kernel/power/block_io.c b/kernel/power/block_io.c index 2b7898a..37412f7 100644 --- a/kernel/power/block_io.c +++ b/kernel/power/block_io.c @@ -3,6 +3,7 @@ * * Copyright (C) 1998,2001-2005 Pavel Machek * Copyright (C) 2006 Rafael J. Wysocki + * Copyright (C) 2004-2008 Nigel Cunningham (nigel at tuxonice net) * * This file is released under the GPLv2. */ @@ -14,6 +15,9 @@ #include "power.h" +static char *sws_writer_buffer; +static unsigned long sws_writer_buffer_pos; + /** * submit - submit BIO request. * @rw: READ or WRITE. @@ -74,6 +78,83 @@ int sws_bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain) virt_to_page(addr), bio_chain); } +int sws_rw_buffer_init(int writing) +{ + BUG_ON(sws_writer_buffer || sws_writer_buffer_pos); + + sws_writer_buffer = (void *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH); + if (sws_writer_buffer && !writing) + sws_writer_buffer_pos = PAGE_SIZE; + + return sws_writer_buffer ? 0 : -ENOMEM; +} + +/** + * sws_rw_buffer - combine smaller buffers into PAGE_SIZE I/O + * @writing: Bool - whether writing (or reading). + * @buffer: The start of the buffer to write or fill. + * @buffer_size: The size of the buffer to write or fill. + **/ +int sws_rw_buffer(int writing, char *buffer, int buffer_size) +{ + int bytes_left = buffer_size, ret; + + while (bytes_left) { + char *source_start = buffer + buffer_size - bytes_left; + char *dest_start = sws_writer_buffer + sws_writer_buffer_pos; + int capacity = PAGE_SIZE - sws_writer_buffer_pos; + char *to = writing ? dest_start : source_start; + char *from = writing ? source_start : dest_start; + + if (bytes_left <= capacity) { + memcpy(to, from, bytes_left); + sws_writer_buffer_pos += bytes_left; + return 0; + } + + /* Complete this page and start a new one */ + memcpy(to, from, capacity); + bytes_left -= capacity; + + if (writing) { + ret = sws_io_ops->write_page(sws_writer_buffer, NULL); + clear_page(sws_writer_buffer); + if (ret) + return ret; + } else { + ret = sws_io_ops->read_page(sws_writer_buffer, NULL); + if (ret) + return ret; + } + + sws_writer_buffer_pos = 0; + } + + return 0; +} + +int sws_rw_buffer_flush_page(int writing) +{ + int ret = 0; + if (writing && sws_writer_buffer_pos) + ret = sws_io_ops->write_page(sws_writer_buffer, NULL); + sws_writer_buffer_pos = writing ? 0 : PAGE_SIZE; + return ret; +} + +int sws_rw_buffer_finish(int writing) +{ + int ret = 0; + + ret = sws_rw_buffer_flush_page(writing); + + free_page((unsigned long)sws_writer_buffer); + sws_writer_buffer = NULL; + sws_writer_buffer_pos = 0; + + return ret; +} + int sws_wait_on_bio_chain(struct bio **bio_chain) { struct bio *bio; diff --git a/kernel/power/power.h b/kernel/power/power.h index 0f08de4..50a888a 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -3,6 +3,8 @@ #include #include +struct swap_map_handle; + struct swsusp_info { struct new_utsname uts; u32 version_code; @@ -161,6 +163,10 @@ extern int sws_bio_read_page(pgoff_t page_off, void *addr, extern int sws_bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain); extern int sws_wait_on_bio_chain(struct bio **bio_chain); +extern int sws_rw_buffer_init(int writing); +extern int sws_rw_buffer_finish(int writing); +extern int sws_rw_buffer_flush_page(int writing); +extern int sws_rw_buffer(int writing, char *buffer, int buffer_size); struct timeval; /* kernel/power/swsusp.c */ -- 1.7.0.2