Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757486Ab0FBIy1 (ORCPT ); Wed, 2 Jun 2010 04:54:27 -0400 Received: from mail.pripojeni.net ([217.66.174.14]:59180 "EHLO mail.jetsystems.cz" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751799Ab0FBIxT (ORCPT ); Wed, 2 Jun 2010 04:53:19 -0400 From: Jiri Slaby To: rjw@sisk.pl Cc: pavel@ucw.cz, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, jirislaby@gmail.com Subject: [PATCH 6/9] PM / Hibernate: split snapshot_read_next Date: Wed, 2 Jun 2010 10:52:45 +0200 Message-Id: <1275468768-28229-6-git-send-email-jslaby@suse.cz> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1275468768-28229-1-git-send-email-jslaby@suse.cz> References: <1275468768-28229-1-git-send-email-jslaby@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5322 Lines: 164 When writing the snapshot, do the initialization and header write in a separate function. This makes the code more readable and lowers complexity of snapshot_read_next. Signed-off-by: Jiri Slaby Cc: "Rafael J. Wysocki" --- kernel/power/power.h | 2 + kernel/power/snapshot.c | 65 ++++++++++++++++++++++++++++++---------------- kernel/power/swap.c | 14 +++------- 3 files changed, 48 insertions(+), 33 deletions(-) diff --git a/kernel/power/power.h b/kernel/power/power.h index 812b66c..ff3f63f 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -171,6 +171,8 @@ struct hibernate_io_ops { extern unsigned int snapshot_additional_pages(struct zone *zone); extern unsigned long snapshot_get_image_size(void); +extern int snapshot_write_init(struct hibernate_io_handle *io_handle, + struct snapshot_handle *handle); extern int snapshot_read_next(struct snapshot_handle *handle); extern int snapshot_write_next(struct snapshot_handle *handle); extern void snapshot_write_finalize(struct snapshot_handle *handle); diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 25ce010..4600d15 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1598,10 +1598,46 @@ pack_pfns(unsigned long *buf, struct memory_bitmap *bm) } /** + * snapshot_write_init - initialization before writing the snapshot to + * a backing storage + * + * This function *must* be called before snapshot_read_next to initialize + * @handle and write a header. + * + * @io_handle: handle used when writing the initial info onto storage + * @handle: snapshot handle to init + */ +int snapshot_write_init(struct hibernate_io_handle *io_handle, + struct snapshot_handle *handle) +{ + int ret; + + /* This makes the buffer be freed by swsusp_free() */ + buffer = get_image_page(GFP_ATOMIC, PG_ANY); + if (!buffer) + return -ENOMEM; + init_header(buffer); + ret = hib_buffer_init_write(io_handle); + if (ret) + return ret; + ret = hib_buffer_write(io_handle, buffer, sizeof(struct swsusp_info)); + if (ret) + goto finish; + hib_buffer_finish_write(io_handle); + memory_bm_position_reset(&orig_bm); + memory_bm_position_reset(©_bm); + handle->buffer = buffer; + return 0; +finish: + hib_buffer_finish_write(io_handle); + return ret; +} + +/** * snapshot_read_next - used for reading the system memory snapshot. * - * On the first call to it @handle should point to a zeroed - * snapshot_handle structure. The structure gets updated and a pointer + * Before calling this function, snapshot_write_init has to be called with + * handle passed as @handle here. The structure gets updated and a pointer * to it should be passed to this function every next time. * * On success the function returns a positive number. Then, the caller @@ -1613,31 +1649,12 @@ pack_pfns(unsigned long *buf, struct memory_bitmap *bm) * structure pointed to by @handle is not updated and should not be used * any more. */ - int snapshot_read_next(struct snapshot_handle *handle) { - if (handle->cur > nr_meta_pages + nr_copy_pages) - return 0; - - if (!buffer) { - /* This makes the buffer be freed by swsusp_free() */ - buffer = get_image_page(GFP_ATOMIC, PG_ANY); - if (!buffer) - return -ENOMEM; - } - if (!handle->cur) { - int error; - - error = init_header((struct swsusp_info *)buffer); - if (error) - return error; - handle->buffer = buffer; - memory_bm_position_reset(&orig_bm); - memory_bm_position_reset(©_bm); - } else if (handle->cur <= nr_meta_pages) { + if (handle->cur < nr_meta_pages) { memset(buffer, 0, PAGE_SIZE); pack_pfns(buffer, &orig_bm); - } else { + } else if (handle->cur < nr_meta_pages + nr_copy_pages) { struct page *page; page = pfn_to_page(memory_bm_next_pfn(©_bm)); @@ -1655,6 +1672,8 @@ int snapshot_read_next(struct snapshot_handle *handle) } else { handle->buffer = page_address(page); } + } else { + return 0; } handle->cur++; return PAGE_SIZE; diff --git a/kernel/power/swap.c b/kernel/power/swap.c index f09494e..9b319f1 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -448,7 +448,6 @@ int swsusp_write(unsigned int flags) { struct hibernate_io_handle *io_handle; struct snapshot_handle snapshot; - struct swsusp_info *header; unsigned long pages; int error; @@ -464,17 +463,12 @@ int swsusp_write(unsigned int flags) goto out_finish; } memset(&snapshot, 0, sizeof(struct snapshot_handle)); - error = snapshot_read_next(&snapshot); - if (error < PAGE_SIZE) { - if (error >= 0) - error = -EFAULT; - + error = snapshot_write_init(io_handle, &snapshot); + if (error) { + printk(KERN_ERR "PM: Cannot init writer\n"); goto out_finish; } - header = (struct swsusp_info *)data_of(snapshot); - error = hibernate_io_ops->write_page(io_handle, header, NULL); - if (!error) - error = save_image(io_handle, &snapshot, pages - 1); + error = save_image(io_handle, &snapshot, pages - 1); out_finish: error = hibernate_io_ops->writer_finish(io_handle, flags, error); return error; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/