Merge tag 'v4.15-rc1' into next-seccomp

Linux 4.15-rc1

1 files changed, 36 insertions, 16 deletions

diff --git a/mm/page_io.c b/mm/page_io.c
index b6c4ac388209..e93f1a4cacd7 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  linux/mm/page_io.c
  *
@@ -22,21 +23,27 @@
 #include <linux/frontswap.h>
 #include <linux/blkdev.h>
 #include <linux/uio.h>
+#include <linux/sched/task.h>
 #include <asm/pgtable.h>
 
 static struct bio *get_swap_bio(gfp_t gfp_flags,
 				struct page *page, bio_end_io_t end_io)
 {
+	int i, nr = hpage_nr_pages(page);
 	struct bio *bio;
 
-	bio = bio_alloc(gfp_flags, 1);
+	bio = bio_alloc(gfp_flags, nr);
 	if (bio) {
-		bio->bi_iter.bi_sector = map_swap_page(page, &bio->bi_bdev);
+		struct block_device *bdev;
+
+		bio->bi_iter.bi_sector = map_swap_page(page, &bdev);
+		bio_set_dev(bio, bdev);
 		bio->bi_iter.bi_sector <<= PAGE_SHIFT - 9;
 		bio->bi_end_io = end_io;
 
-		bio_add_page(bio, page, PAGE_SIZE, 0);
-		BUG_ON(bio->bi_iter.bi_size != PAGE_SIZE);
+		for (i = 0; i < nr; i++)
+			bio_add_page(bio, page + i, PAGE_SIZE, 0);
+		VM_BUG_ON(bio->bi_iter.bi_size != PAGE_SIZE * nr);
 	}
 	return bio;
 }
@@ -57,8 +64,7 @@ void end_swap_bio_write(struct bio *bio)
 		 */
 		set_page_dirty(page);
 		pr_alert("Write-error on swap-device (%u:%u:%llu)\n",
-			 imajor(bio->bi_bdev->bd_inode),
-			 iminor(bio->bi_bdev->bd_inode),
+			 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
 			 (unsigned long long)bio->bi_iter.bi_sector);
 		ClearPageReclaim(page);
 	}
@@ -123,8 +129,7 @@ static void end_swap_bio_read(struct bio *bio)
 		SetPageError(page);
 		ClearPageUptodate(page);
 		pr_alert("Read-error on swap-device (%u:%u:%llu)\n",
-			 imajor(bio->bi_bdev->bd_inode),
-			 iminor(bio->bi_bdev->bd_inode),
+			 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
 			 (unsigned long long)bio->bi_iter.bi_sector);
 		goto out;
 	}
@@ -136,6 +141,7 @@ out:
 	WRITE_ONCE(bio->bi_private, NULL);
 	bio_put(bio);
 	wake_up_process(waiter);
+	put_task_struct(waiter);
 }
 
 int generic_swapfile_activate(struct swap_info_struct *sis,
@@ -260,6 +266,15 @@ static sector_t swap_page_sector(struct page *page)
 	return (sector_t)__page_file_index(page) << (PAGE_SHIFT - 9);
 }
 
+static inline void count_swpout_vm_event(struct page *page)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	if (unlikely(PageTransHuge(page)))
+		count_vm_event(THP_SWPOUT);
+#endif
+	count_vm_events(PSWPOUT, hpage_nr_pages(page));
+}
+
 int __swap_writepage(struct page *page, struct writeback_control *wbc,
 		bio_end_io_t end_write_func)
 {
@@ -311,7 +326,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
 
 	ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, wbc);
 	if (!ret) {
-		count_vm_event(PSWPOUT);
+		count_swpout_vm_event(page);
 		return 0;
 	}
 
@@ -324,7 +339,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
 		goto out;
 	}
 	bio->bi_opf = REQ_OP_WRITE | wbc_to_write_flags(wbc);
-	count_vm_event(PSWPOUT);
+	count_swpout_vm_event(page);
 	set_page_writeback(page);
 	unlock_page(page);
 	submit_bio(bio);
@@ -332,15 +347,15 @@ out:
 	return ret;
 }
 
-int swap_readpage(struct page *page, bool do_poll)
+int swap_readpage(struct page *page, bool synchronous)
 {
 	struct bio *bio;
 	int ret = 0;
 	struct swap_info_struct *sis = page_swap_info(page);
 	blk_qc_t qc;
-	struct block_device *bdev;
+	struct gendisk *disk;
 
-	VM_BUG_ON_PAGE(!PageSwapCache(page), page);
+	VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page);
 	VM_BUG_ON_PAGE(!PageLocked(page), page);
 	VM_BUG_ON_PAGE(PageUptodate(page), page);
 	if (frontswap_load(page) == 0) {
@@ -377,18 +392,23 @@ int swap_readpage(struct page *page, bool do_poll)
 		ret = -ENOMEM;
 		goto out;
 	}
-	bdev = bio->bi_bdev;
+	disk = bio->bi_disk;
+	/*
+	 * Keep this task valid during swap readpage because the oom killer may
+	 * attempt to access it in the page fault retry time check.
+	 */
+	get_task_struct(current);
 	bio->bi_private = current;
 	bio_set_op_attrs(bio, REQ_OP_READ, 0);
 	count_vm_event(PSWPIN);
 	bio_get(bio);
 	qc = submit_bio(bio);
-	while (do_poll) {
+	while (synchronous) {
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		if (!READ_ONCE(bio->bi_private))
 			break;
 
-		if (!blk_mq_poll(bdev_get_queue(bdev), qc))
+		if (!blk_poll(disk->queue, qc))
 			break;
 	}
 	__set_current_state(TASK_RUNNING);