[PATCH 1/4] zram: complete parent bio on allocation failure in read_from_bdev_async()

[Andrew Stellman]

read_from_bdev_async() silently returns without completing the parent
bio when either kmalloc or bio_alloc fails. The caller has already
submitted the parent bio for asynchronous completion, so returning
without calling bio_endio(parent) leaves the I/O hanging indefinitely.

Set parent->bi_status to BLK_STS_IOERR and call bio_endio(parent) on
both allocation failure paths, matching the error-completion pattern
used in zram_async_read_endio().

Signed-off-by: Andrew Stellman <astellman@xxxxxxxxxxxxxxxxxxx>
---
 drivers/block/zram/zram_drv.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index af67937..f41f1ca 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1437,12 +1437,17 @@ static void read_from_bdev_async(struct zram *zram, struct page *page,
 	struct bio *bio;
 
 	req = kmalloc_obj(*req, GFP_NOIO);
-	if (!req)
+	if (!req) {
+		parent->bi_status = BLK_STS_IOERR;
+		bio_endio(parent);
 		return;
+	}
 
 	bio = bio_alloc(zram->bdev, 1, parent->bi_opf, GFP_NOIO);
 	if (!bio) {
 		kfree(req);
+		parent->bi_status = BLK_STS_IOERR;
+		bio_endio(parent);
 		return;
 	}
 
-- 
2.34.1