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[PATCH] swsusp: rearrange swap-handling code
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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: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Rafael J. Wysocki authored and Linus Torvalds committed Dec 7, 2006
1 parent 915bae9 commit 3fc6b34
Showing 1 changed file with 112 additions and 109 deletions.
221 changes: 112 additions & 109 deletions kernel/power/swap.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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)
{
Expand Down Expand Up @@ -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);
Expand All @@ -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)
{
Expand Down Expand Up @@ -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
Expand Down

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