summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--include/linux/swap.h5
-rw-r--r--kernel/power/swap.c93
-rw-r--r--mm/page_io.c25
3 files changed, 98 insertions, 25 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h
index a2f5ad7..3d434cb 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -12,6 +12,8 @@
struct notifier_block;
+struct bio;
+
#define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
#define SWAP_FLAG_PRIO_MASK 0x7fff
#define SWAP_FLAG_PRIO_SHIFT 0
@@ -216,7 +218,8 @@ extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *);
/* linux/mm/page_io.c */
extern int swap_readpage(struct file *, struct page *);
extern int swap_writepage(struct page *page, struct writeback_control *wbc);
-extern int rw_swap_page_sync(int, swp_entry_t, struct page *);
+extern int rw_swap_page_sync(int rw, swp_entry_t entry, struct page *page,
+ struct bio **bio_chain);
/* linux/mm/swap_state.c */
extern struct address_space swapper_space;
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 79b66e7..2dc883d 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -49,18 +49,16 @@ static int mark_swapfiles(swp_entry_t start)
{
int error;
- rw_swap_page_sync(READ,
- swp_entry(root_swap, 0),
- virt_to_page((unsigned long)&swsusp_header));
+ rw_swap_page_sync(READ, swp_entry(root_swap, 0),
+ virt_to_page((unsigned long)&swsusp_header), NULL);
if (!memcmp("SWAP-SPACE",swsusp_header.sig, 10) ||
!memcmp("SWAPSPACE2",swsusp_header.sig, 10)) {
memcpy(swsusp_header.orig_sig,swsusp_header.sig, 10);
memcpy(swsusp_header.sig,SWSUSP_SIG, 10);
swsusp_header.image = start;
- error = rw_swap_page_sync(WRITE,
- swp_entry(root_swap, 0),
- virt_to_page((unsigned long)
- &swsusp_header));
+ error = rw_swap_page_sync(WRITE, swp_entry(root_swap, 0),
+ virt_to_page((unsigned long)&swsusp_header),
+ NULL);
} else {
pr_debug("swsusp: Partition is not swap space.\n");
error = -ENODEV;
@@ -88,16 +86,37 @@ static int swsusp_swap_check(void) /* This is called before saving image */
* write_page - Write one page to given swap location.
* @buf: Address we're writing.
* @offset: Offset of the swap page we're writing to.
+ * @bio_chain: Link the next write BIO here
*/
-static int write_page(void *buf, unsigned long offset)
+static int write_page(void *buf, unsigned long offset, struct bio **bio_chain)
{
swp_entry_t entry;
int error = -ENOSPC;
if (offset) {
+ struct page *page = virt_to_page(buf);
+
+ if (bio_chain) {
+ /*
+ * Whether or not we successfully allocated a copy page,
+ * we take a ref on the page here. It gets undone in
+ * wait_on_bio_chain().
+ */
+ struct page *page_copy;
+ page_copy = alloc_page(GFP_ATOMIC);
+ if (page_copy == NULL) {
+ WARN_ON_ONCE(1);
+ bio_chain = NULL; /* Go synchronous */
+ get_page(page);
+ } else {
+ memcpy(page_address(page_copy),
+ page_address(page), PAGE_SIZE);
+ page = page_copy;
+ }
+ }
entry = swp_entry(root_swap, offset);
- error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf));
+ error = rw_swap_page_sync(WRITE, entry, page, bio_chain);
}
return error;
}
@@ -185,37 +204,68 @@ static int get_swap_writer(struct swap_map_handle *handle)
return 0;
}
-static int swap_write_page(struct swap_map_handle *handle, void *buf)
+static int wait_on_bio_chain(struct bio **bio_chain)
{
- int error;
+ struct bio *bio;
+ struct bio *next_bio;
+ int ret = 0;
+
+ if (bio_chain == NULL)
+ return 0;
+
+ bio = *bio_chain;
+ 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)
+{
+ int error = 0;
unsigned long offset;
if (!handle->cur)
return -EINVAL;
offset = alloc_swap_page(root_swap, handle->bitmap);
- error = write_page(buf, offset);
+ error = write_page(buf, offset, bio_chain);
if (error)
return error;
handle->cur->entries[handle->k++] = offset;
if (handle->k >= MAP_PAGE_ENTRIES) {
+ error = wait_on_bio_chain(bio_chain);
+ if (error)
+ goto out;
offset = alloc_swap_page(root_swap, handle->bitmap);
if (!offset)
return -ENOSPC;
handle->cur->next_swap = offset;
- error = write_page(handle->cur, handle->cur_swap);
+ error = write_page(handle->cur, handle->cur_swap, NULL);
if (error)
- return error;
+ goto out;
memset(handle->cur, 0, PAGE_SIZE);
handle->cur_swap = offset;
handle->k = 0;
}
- return 0;
+out:
+ return error;
}
static int flush_swap_writer(struct swap_map_handle *handle)
{
if (handle->cur && handle->cur_swap)
- return write_page(handle->cur, handle->cur_swap);
+ return write_page(handle->cur, handle->cur_swap, NULL);
else
return -EINVAL;
}
@@ -232,6 +282,8 @@ static int save_image(struct swap_map_handle *handle,
int ret;
int error = 0;
int nr_pages;
+ int err2;
+ struct bio *bio;
struct timeval start;
struct timeval stop;
@@ -240,11 +292,13 @@ static int save_image(struct swap_map_handle *handle,
if (!m)
m = 1;
nr_pages = 0;
+ bio = NULL;
do_gettimeofday(&start);
do {
ret = snapshot_read_next(snapshot, PAGE_SIZE);
if (ret > 0) {
- error = swap_write_page(handle, data_of(*snapshot));
+ error = swap_write_page(handle, data_of(*snapshot),
+ &bio);
if (error)
break;
if (!(nr_pages % m))
@@ -252,8 +306,11 @@ static int save_image(struct swap_map_handle *handle,
nr_pages++;
}
} while (ret > 0);
+ err2 = wait_on_bio_chain(&bio);
do_gettimeofday(&stop);
if (!error)
+ error = err2;
+ if (!error)
printk("\b\b\b\bdone\n");
show_speed(&start, &stop, nr_to_write, "Wrote");
return error;
@@ -307,7 +364,7 @@ int swsusp_write(void)
error = get_swap_writer(&handle);
if (!error) {
unsigned long start = handle.cur_swap;
- error = swap_write_page(&handle, header);
+ error = swap_write_page(&handle, header, NULL);
if (!error)
error = save_image(&handle, &snapshot,
header->pages - 1);
diff --git a/mm/page_io.c b/mm/page_io.c
index d2f0a57..f46a986 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -156,10 +156,12 @@ out:
* We use end_swap_bio_read() even for writes, because it happens to do what
* we want.
*/
-int rw_swap_page_sync(int rw, swp_entry_t entry, struct page *page)
+int rw_swap_page_sync(int rw, swp_entry_t entry, struct page *page,
+ struct bio **bio_chain)
{
struct bio *bio;
int ret = 0;
+ int bio_rw;
lock_page(page);
@@ -170,11 +172,22 @@ int rw_swap_page_sync(int rw, swp_entry_t entry, struct page *page)
goto out;
}
- submit_bio(rw | (1 << BIO_RW_SYNC), bio);
- wait_on_page_locked(page);
-
- if (!PageUptodate(page) || PageError(page))
- ret = -EIO;
+ bio_rw = rw;
+ if (!bio_chain)
+ bio_rw |= (1 << BIO_RW_SYNC);
+ if (bio_chain)
+ bio_get(bio);
+ submit_bio(bio_rw, bio);
+ if (bio_chain == NULL) {
+ wait_on_page_locked(page);
+
+ if (!PageUptodate(page) || PageError(page))
+ ret = -EIO;
+ }
+ if (bio_chain) {
+ bio->bi_private = *bio_chain;
+ *bio_chain = bio;
+ }
out:
return ret;
}
OpenPOWER on IntegriCloud