[PATCH -mm 2/6] swsusp: Rearrange swap-handling code

Rafael J. Wysocki
2006-09-20T21:20:30Z

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>
---
kernel/power/swap.c | 219 ++++++++++++++++++++++++++--------------------------
1 file changed, 111 insertions(+), 108 deletions(-)

Index: linux-2.6.18-rc7-mm1/kernel/power/swap.c
===================================================================
--- linux-2.6.18-rc7-mm1.orig/kernel/power/swap.c
+++ linux-2.6.18-rc7-mm1/kernel/power/swap.c
@@ -41,10 +41,120 @@ 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 {
+ get_page(page);
+ 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 +276,6 @@ static void release_swap_writer(struct s
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 +295,6 @@ static int get_swap_writer(struct swap_m
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)
{
@@ -384,65 +446,6 @@ 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 {
- get_page(page);
- 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