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Commit 3fc6b34f authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
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[PATCH] swsusp: rearrange swap-handling code 



Rearrange the code in kernel/power/swap.c so that the next patch is more
readable.

[This patch only moves the existing code.]

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 915bae9e

kernel/power/swap.c

+112 −109
Original line number Diff line number Diff line
@@ -41,10 +41,121 @@ static struct swsusp_header { 
} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header;



/*

 * Saving part...

 * General things

 */



static unsigned short root_swap = 0xffff;

static struct block_device *resume_bdev;



/**

 *	submit - submit BIO request.

 *	@rw:	READ or WRITE.

 *	@off	physical offset of page.

 *	@page:	page we're reading or writing.

 *	@bio_chain: list of pending biod (for async reading)

 *

 *	Straight from the textbook - allocate and initialize the bio.

 *	If we're reading, make sure the page is marked as dirty.

 *	Then submit it and, if @bio_chain == NULL, wait.

 */

static int submit(int rw, pgoff_t page_off, struct page *page,

			struct bio **bio_chain)

{

	struct bio *bio;



	bio = bio_alloc(GFP_ATOMIC, 1);

	if (!bio)

		return -ENOMEM;

	bio->bi_sector = page_off * (PAGE_SIZE >> 9);

	bio->bi_bdev = resume_bdev;

	bio->bi_end_io = end_swap_bio_read;



	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {

		printk("swsusp: ERROR: adding page to bio at %ld\n", page_off);

		bio_put(bio);

		return -EFAULT;

	}



	lock_page(page);

	bio_get(bio);



	if (bio_chain == NULL) {

		submit_bio(rw | (1 << BIO_RW_SYNC), bio);

		wait_on_page_locked(page);

		if (rw == READ)

			bio_set_pages_dirty(bio);

		bio_put(bio);

	} else {

		if (rw == READ)

			get_page(page);	/* These pages are freed later */

		bio->bi_private = *bio_chain;

		*bio_chain = bio;

		submit_bio(rw | (1 << BIO_RW_SYNC), bio);

	}

	return 0;

}



static int bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)

{

	return submit(READ, page_off, virt_to_page(addr), bio_chain);

}



static int bio_write_page(pgoff_t page_off, void *addr)

{

	return submit(WRITE, page_off, virt_to_page(addr), NULL);

}



static int wait_on_bio_chain(struct bio **bio_chain)

{

	struct bio *bio;

	struct bio *next_bio;

	int ret = 0;



	if (bio_chain == NULL)

		return 0;



	bio = *bio_chain;

	if (bio == NULL)

		return 0;

	while (bio) {

		struct page *page;



		next_bio = bio->bi_private;

		page = bio->bi_io_vec[0].bv_page;

		wait_on_page_locked(page);

		if (!PageUptodate(page) || PageError(page))

			ret = -EIO;

		put_page(page);

		bio_put(bio);

		bio = next_bio;

	}

	*bio_chain = NULL;

	return ret;

}



static void show_speed(struct timeval *start, struct timeval *stop,

			unsigned nr_pages, char *msg)

{

	s64 elapsed_centisecs64;

	int centisecs;

	int k;

	int kps;



	elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);

	do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);

	centisecs = elapsed_centisecs64;

	if (centisecs == 0)

		centisecs = 1;	/* avoid div-by-zero */

	k = nr_pages * (PAGE_SIZE / 1024);

	kps = (k * 100) / centisecs;

	printk("%s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n", msg, k,

			centisecs / 100, centisecs % 100,

			kps / 1000, (kps % 1000) / 10);

}



/*

 * Saving part

 */



static int mark_swapfiles(swp_entry_t start)

{
@@ -166,26 +277,6 @@ static void release_swap_writer(struct swap_map_handle *handle) 
	handle->bitmap = NULL;

}



static void show_speed(struct timeval *start, struct timeval *stop,

			unsigned nr_pages, char *msg)

{

	s64 elapsed_centisecs64;

	int centisecs;

	int k;

	int kps;



	elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);

	do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);

	centisecs = elapsed_centisecs64;

	if (centisecs == 0)

		centisecs = 1;	/* avoid div-by-zero */

	k = nr_pages * (PAGE_SIZE / 1024);

	kps = (k * 100) / centisecs;

	printk("%s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n", msg, k,

			centisecs / 100, centisecs % 100,

			kps / 1000, (kps % 1000) / 10);

}



static int get_swap_writer(struct swap_map_handle *handle)

{

	handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
@@ -205,34 +296,6 @@ static int get_swap_writer(struct swap_map_handle *handle) 
	return 0;

}



static int wait_on_bio_chain(struct bio **bio_chain)

{

	struct bio *bio;

	struct bio *next_bio;

	int ret = 0;



	if (bio_chain == NULL)

		return 0;



	bio = *bio_chain;

	if (bio == NULL)

		return 0;

	while (bio) {

		struct page *page;



		next_bio = bio->bi_private;

		page = bio->bi_io_vec[0].bv_page;

		wait_on_page_locked(page);

		if (!PageUptodate(page) || PageError(page))

			ret = -EIO;

		put_page(page);

		bio_put(bio);

		bio = next_bio;

	}

	*bio_chain = NULL;

	return ret;

}



static int swap_write_page(struct swap_map_handle *handle, void *buf,

				struct bio **bio_chain)

{
@@ -384,66 +447,6 @@ int swsusp_write(void) 
	return error;

}



static struct block_device *resume_bdev;



/**

 *	submit - submit BIO request.

 *	@rw:	READ or WRITE.

 *	@off	physical offset of page.

 *	@page:	page we're reading or writing.

 *	@bio_chain: list of pending biod (for async reading)

 *

 *	Straight from the textbook - allocate and initialize the bio.

 *	If we're reading, make sure the page is marked as dirty.

 *	Then submit it and, if @bio_chain == NULL, wait.

 */

static int submit(int rw, pgoff_t page_off, struct page *page,

			struct bio **bio_chain)

{

	struct bio *bio;



	bio = bio_alloc(GFP_ATOMIC, 1);

	if (!bio)

		return -ENOMEM;

	bio->bi_sector = page_off * (PAGE_SIZE >> 9);

	bio->bi_bdev = resume_bdev;

	bio->bi_end_io = end_swap_bio_read;



	if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {

		printk("swsusp: ERROR: adding page to bio at %ld\n", page_off);

		bio_put(bio);

		return -EFAULT;

	}



	lock_page(page);

	bio_get(bio);



	if (bio_chain == NULL) {

		submit_bio(rw | (1 << BIO_RW_SYNC), bio);

		wait_on_page_locked(page);

		if (rw == READ)

			bio_set_pages_dirty(bio);

		bio_put(bio);

	} else {

		if (rw == READ)

			get_page(page);	/* These pages are freed later */

		bio->bi_private = *bio_chain;

		*bio_chain = bio;

		submit_bio(rw | (1 << BIO_RW_SYNC), bio);

	}

	return 0;

}



static int bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain)

{

	return submit(READ, page_off, virt_to_page(addr), bio_chain);

}



static int bio_write_page(pgoff_t page_off, void *addr)

{

	return submit(WRITE, page_off, virt_to_page(addr), NULL);

}



/**

 *	The following functions allow us to read data using a swap map

 *	in a file-alike way