suspend: simplify block I/O handling
Stop abusing struct page functionality and the swap end_io handler, and
instead add a modified version of the blk-lib.c bio_batch helpers.
Also move the block I/O code into swap.c as they are directly tied into
each other.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Ming Lin <mlin@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 570aff8..2f30ca9 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -212,7 +212,84 @@
*/
static unsigned short root_swap = 0xffff;
-struct block_device *hib_resume_bdev;
+static struct block_device *hib_resume_bdev;
+
+struct hib_bio_batch {
+ atomic_t count;
+ wait_queue_head_t wait;
+ int error;
+};
+
+static void hib_init_batch(struct hib_bio_batch *hb)
+{
+ atomic_set(&hb->count, 0);
+ init_waitqueue_head(&hb->wait);
+ hb->error = 0;
+}
+
+static void hib_end_io(struct bio *bio, int error)
+{
+ struct hib_bio_batch *hb = bio->bi_private;
+ const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ struct page *page = bio->bi_io_vec[0].bv_page;
+
+ if (!uptodate || error) {
+ printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
+ imajor(bio->bi_bdev->bd_inode),
+ iminor(bio->bi_bdev->bd_inode),
+ (unsigned long long)bio->bi_iter.bi_sector);
+
+ if (!error)
+ error = -EIO;
+ }
+
+ if (bio_data_dir(bio) == WRITE)
+ put_page(page);
+
+ if (error && !hb->error)
+ hb->error = error;
+ if (atomic_dec_and_test(&hb->count))
+ wake_up(&hb->wait);
+
+ bio_put(bio);
+}
+
+static int hib_submit_io(int rw, pgoff_t page_off, void *addr,
+ struct hib_bio_batch *hb)
+{
+ struct page *page = virt_to_page(addr);
+ struct bio *bio;
+ int error = 0;
+
+ bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
+ bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
+ bio->bi_bdev = hib_resume_bdev;
+
+ if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
+ printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
+ (unsigned long long)bio->bi_iter.bi_sector);
+ bio_put(bio);
+ return -EFAULT;
+ }
+
+ if (hb) {
+ bio->bi_end_io = hib_end_io;
+ bio->bi_private = hb;
+ atomic_inc(&hb->count);
+ submit_bio(rw, bio);
+ } else {
+ error = submit_bio_wait(rw, bio);
+ bio_put(bio);
+ }
+
+ return error;
+}
+
+static int hib_wait_io(struct hib_bio_batch *hb)
+{
+ wait_event(hb->wait, atomic_read(&hb->count) == 0);
+ return hb->error;
+}
/*
* Saving part
@@ -222,7 +299,7 @@
{
int error;
- hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
+ hib_submit_io(READ_SYNC, swsusp_resume_block, 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);
@@ -231,7 +308,7 @@
swsusp_header->flags = flags;
if (flags & SF_CRC32_MODE)
swsusp_header->crc32 = handle->crc32;
- error = hib_bio_write_page(swsusp_resume_block,
+ error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
swsusp_header, NULL);
} else {
printk(KERN_ERR "PM: Swap header not found!\n");
@@ -271,10 +348,10 @@
* 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
+ * @hb: bio completion batch
*/
-static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
+static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
{
void *src;
int ret;
@@ -282,13 +359,13 @@
if (!offset)
return -ENOSPC;
- if (bio_chain) {
+ if (hb) {
src = (void *)__get_free_page(__GFP_WAIT | __GFP_NOWARN |
__GFP_NORETRY);
if (src) {
copy_page(src, buf);
} else {
- ret = hib_wait_on_bio_chain(bio_chain); /* Free pages */
+ ret = hib_wait_io(hb); /* Free pages */
if (ret)
return ret;
src = (void *)__get_free_page(__GFP_WAIT |
@@ -298,14 +375,14 @@
copy_page(src, buf);
} else {
WARN_ON_ONCE(1);
- bio_chain = NULL; /* Go synchronous */
+ hb = NULL; /* Go synchronous */
src = buf;
}
}
} else {
src = buf;
}
- return hib_bio_write_page(offset, src, bio_chain);
+ return hib_submit_io(WRITE_SYNC, offset, src, hb);
}
static void release_swap_writer(struct swap_map_handle *handle)
@@ -348,7 +425,7 @@
}
static int swap_write_page(struct swap_map_handle *handle, void *buf,
- struct bio **bio_chain)
+ struct hib_bio_batch *hb)
{
int error = 0;
sector_t offset;
@@ -356,7 +433,7 @@
if (!handle->cur)
return -EINVAL;
offset = alloc_swapdev_block(root_swap);
- error = write_page(buf, offset, bio_chain);
+ error = write_page(buf, offset, hb);
if (error)
return error;
handle->cur->entries[handle->k++] = offset;
@@ -365,15 +442,15 @@
if (!offset)
return -ENOSPC;
handle->cur->next_swap = offset;
- error = write_page(handle->cur, handle->cur_swap, bio_chain);
+ error = write_page(handle->cur, handle->cur_swap, hb);
if (error)
goto out;
clear_page(handle->cur);
handle->cur_swap = offset;
handle->k = 0;
- if (bio_chain && low_free_pages() <= handle->reqd_free_pages) {
- error = hib_wait_on_bio_chain(bio_chain);
+ if (hb && low_free_pages() <= handle->reqd_free_pages) {
+ error = hib_wait_io(hb);
if (error)
goto out;
/*
@@ -445,23 +522,24 @@
int ret;
int nr_pages;
int err2;
- struct bio *bio;
+ struct hib_bio_batch hb;
ktime_t start;
ktime_t stop;
+ hib_init_batch(&hb);
+
printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
nr_to_write);
m = nr_to_write / 10;
if (!m)
m = 1;
nr_pages = 0;
- bio = NULL;
start = ktime_get();
while (1) {
ret = snapshot_read_next(snapshot);
if (ret <= 0)
break;
- ret = swap_write_page(handle, data_of(*snapshot), &bio);
+ ret = swap_write_page(handle, data_of(*snapshot), &hb);
if (ret)
break;
if (!(nr_pages % m))
@@ -469,7 +547,7 @@
nr_pages / m * 10);
nr_pages++;
}
- err2 = hib_wait_on_bio_chain(&bio);
+ err2 = hib_wait_io(&hb);
stop = ktime_get();
if (!ret)
ret = err2;
@@ -580,7 +658,7 @@
int ret = 0;
int nr_pages;
int err2;
- struct bio *bio;
+ struct hib_bio_batch hb;
ktime_t start;
ktime_t stop;
size_t off;
@@ -589,6 +667,8 @@
struct cmp_data *data = NULL;
struct crc_data *crc = NULL;
+ hib_init_batch(&hb);
+
/*
* We'll limit the number of threads for compression to limit memory
* footprint.
@@ -674,7 +754,6 @@
if (!m)
m = 1;
nr_pages = 0;
- bio = NULL;
start = ktime_get();
for (;;) {
for (thr = 0; thr < nr_threads; thr++) {
@@ -748,7 +827,7 @@
off += PAGE_SIZE) {
memcpy(page, data[thr].cmp + off, PAGE_SIZE);
- ret = swap_write_page(handle, page, &bio);
+ ret = swap_write_page(handle, page, &hb);
if (ret)
goto out_finish;
}
@@ -759,7 +838,7 @@
}
out_finish:
- err2 = hib_wait_on_bio_chain(&bio);
+ err2 = hib_wait_io(&hb);
stop = ktime_get();
if (!ret)
ret = err2;
@@ -906,7 +985,7 @@
return -ENOMEM;
}
- error = hib_bio_read_page(offset, tmp->map, NULL);
+ error = hib_submit_io(READ_SYNC, offset, tmp->map, NULL);
if (error) {
release_swap_reader(handle);
return error;
@@ -919,7 +998,7 @@
}
static int swap_read_page(struct swap_map_handle *handle, void *buf,
- struct bio **bio_chain)
+ struct hib_bio_batch *hb)
{
sector_t offset;
int error;
@@ -930,7 +1009,7 @@
offset = handle->cur->entries[handle->k];
if (!offset)
return -EFAULT;
- error = hib_bio_read_page(offset, buf, bio_chain);
+ error = hib_submit_io(READ_SYNC, offset, buf, hb);
if (error)
return error;
if (++handle->k >= MAP_PAGE_ENTRIES) {
@@ -968,27 +1047,28 @@
int ret = 0;
ktime_t start;
ktime_t stop;
- struct bio *bio;
+ struct hib_bio_batch hb;
int err2;
unsigned nr_pages;
+ hib_init_batch(&hb);
+
printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
nr_to_read);
m = nr_to_read / 10;
if (!m)
m = 1;
nr_pages = 0;
- bio = NULL;
start = ktime_get();
for ( ; ; ) {
ret = snapshot_write_next(snapshot);
if (ret <= 0)
break;
- ret = swap_read_page(handle, data_of(*snapshot), &bio);
+ ret = swap_read_page(handle, data_of(*snapshot), &hb);
if (ret)
break;
if (snapshot->sync_read)
- ret = hib_wait_on_bio_chain(&bio);
+ ret = hib_wait_io(&hb);
if (ret)
break;
if (!(nr_pages % m))
@@ -996,7 +1076,7 @@
nr_pages / m * 10);
nr_pages++;
}
- err2 = hib_wait_on_bio_chain(&bio);
+ err2 = hib_wait_io(&hb);
stop = ktime_get();
if (!ret)
ret = err2;
@@ -1067,7 +1147,7 @@
unsigned int m;
int ret = 0;
int eof = 0;
- struct bio *bio;
+ struct hib_bio_batch hb;
ktime_t start;
ktime_t stop;
unsigned nr_pages;
@@ -1080,6 +1160,8 @@
struct dec_data *data = NULL;
struct crc_data *crc = NULL;
+ hib_init_batch(&hb);
+
/*
* We'll limit the number of threads for decompression to limit memory
* footprint.
@@ -1190,7 +1272,6 @@
if (!m)
m = 1;
nr_pages = 0;
- bio = NULL;
start = ktime_get();
ret = snapshot_write_next(snapshot);
@@ -1199,7 +1280,7 @@
for(;;) {
for (i = 0; !eof && i < want; i++) {
- ret = swap_read_page(handle, page[ring], &bio);
+ ret = swap_read_page(handle, page[ring], &hb);
if (ret) {
/*
* On real read error, finish. On end of data,
@@ -1226,7 +1307,7 @@
if (!asked)
break;
- ret = hib_wait_on_bio_chain(&bio);
+ ret = hib_wait_io(&hb);
if (ret)
goto out_finish;
have += asked;
@@ -1281,7 +1362,7 @@
* Wait for more data while we are decompressing.
*/
if (have < LZO_CMP_PAGES && asked) {
- ret = hib_wait_on_bio_chain(&bio);
+ ret = hib_wait_io(&hb);
if (ret)
goto out_finish;
have += asked;
@@ -1430,7 +1511,7 @@
if (!IS_ERR(hib_resume_bdev)) {
set_blocksize(hib_resume_bdev, PAGE_SIZE);
clear_page(swsusp_header);
- error = hib_bio_read_page(swsusp_resume_block,
+ error = hib_submit_io(READ_SYNC, swsusp_resume_block,
swsusp_header, NULL);
if (error)
goto put;
@@ -1438,7 +1519,7 @@
if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
/* Reset swap signature now */
- error = hib_bio_write_page(swsusp_resume_block,
+ error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
swsusp_header, NULL);
} else {
error = -EINVAL;
@@ -1482,10 +1563,10 @@
{
int error;
- hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
+ hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
- error = hib_bio_write_page(swsusp_resume_block,
+ error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
swsusp_header, NULL);
} else {
printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
