FAILED: patch "[PATCH] dm writecache: fix writing beyond end of underlying device" failed to apply to 4.19-stable tree

index e8382d73c73c..baf5a9ce2b25 100644
@@ -148,6 +148,7 @@ struct dm_writecache {
 	size_t metadata_sectors;
 	size_t n_blocks;
 	uint64_t seq_count;
+	sector_t data_device_sectors;
 	void *block_start;
 	struct wc_entry *entries;
 	unsigned block_size;

@@ -977,6 +978,8 @@ static void writecache_resume(struct dm_target *ti)
 
 	wc_lock(wc);
 
+	wc->data_device_sectors = i_size_read(wc->dev->bdev->bd_inode) >> SECTOR_SHIFT;
+
 	if (WC_MODE_PMEM(wc)) {
 		persistent_memory_invalidate_cache(wc->memory_map, wc->memory_map_size);
 	} else {

@@ -1646,6 +1649,10 @@ static bool wc_add_block(struct writeback_struct *wb, struct wc_entry *e, gfp_t
 	void *address = memory_data(wc, e);
 
 	persistent_memory_flush_cache(address, block_size);
+
+	if (unlikely(bio_end_sector(&wb->bio) >= wc->data_device_sectors))
+		return true;
+
 	return bio_add_page(&wb->bio, persistent_memory_page(address),
 			    block_size, persistent_memory_page_offset(address)) != 0;
 }

@@ -1717,6 +1724,9 @@ static void __writecache_writeback_pmem(struct dm_writecache *wc, struct writeba
 		if (writecache_has_error(wc)) {
 			bio->bi_status = BLK_STS_IOERR;
 			bio_endio(bio);
+		} else if (unlikely(!bio_sectors(bio))) {
+			bio->bi_status = BLK_STS_OK;
+			bio_endio(bio);
 		} else {
 			submit_bio(bio);
 		}

@@ -1760,6 +1770,14 @@ static void __writecache_writeback_ssd(struct dm_writecache *wc, struct writebac
 			e = f;
 		}
 
+		if (unlikely(to.sector + to.count > wc->data_device_sectors)) {
+			if (to.sector >= wc->data_device_sectors) {
+				writecache_copy_endio(0, 0, c);
+				continue;
+			}
+			from.count = to.count = wc->data_device_sectors - to.sector;
+		}
+
 		dm_kcopyd_copy(wc->dm_kcopyd, &from, 1, &to, 0, writecache_copy_endio, c);
 
 		__writeback_throttle(wc, wbl);

Index: linux-stable/drivers/md/dm-writecache.c
===================================================================
@@ -142,6 +142,7 @@ struct dm_writecache {
 	size_t metadata_sectors;
 	size_t n_blocks;
 	uint64_t seq_count;
+	sector_t data_device_sectors;
 	void *block_start;
 	struct wc_entry *entries;
 	unsigned block_size;

@@ -929,6 +930,8 @@ static void writecache_resume(struct dm_
 
 	wc_lock(wc);
 
+	wc->data_device_sectors = i_size_read(wc->dev->bdev->bd_inode) >> SECTOR_SHIFT;
+
 	if (WC_MODE_PMEM(wc)) {
 		persistent_memory_invalidate_cache(wc->memory_map, wc->memory_map_size);
 	} else {

@@ -1499,6 +1502,10 @@ static bool wc_add_block(struct writebac
 	void *address = memory_data(wc, e);
 
 	persistent_memory_flush_cache(address, block_size);
+
+	if (unlikely(bio_end_sector(&wb->bio) >= wc->data_device_sectors))
+		return true;
+
 	return bio_add_page(&wb->bio, persistent_memory_page(address),
 			    block_size, persistent_memory_page_offset(address)) != 0;
 }

@@ -1571,6 +1578,9 @@ static void __writecache_writeback_pmem(
 		if (writecache_has_error(wc)) {
 			bio->bi_status = BLK_STS_IOERR;
 			bio_endio(&wb->bio);
+		} else if (unlikely(!bio_sectors(&wb->bio))) {
+			bio->bi_status = BLK_STS_OK;
+			bio_endio(&wb->bio);
 		} else {
 			submit_bio(&wb->bio);
 		}

@@ -1614,6 +1624,14 @@ static void __writecache_writeback_ssd(s
 			e = f;
 		}
 
+		if (unlikely(to.sector + to.count > wc->data_device_sectors)) {
+			if (to.sector >= wc->data_device_sectors) {
+				writecache_copy_endio(0, 0, c);
+				continue;
+			}
+			from.count = to.count = wc->data_device_sectors - to.sector;
+		}
+
 		dm_kcopyd_copy(wc->dm_kcopyd, &from, 1, &to, 0, writecache_copy_endio, c);
 
 		__writeback_throttle(wc, wbl);