block-map: add __GFP_ZERO flag for alloc_page in function bio_copy_kern

commit cc8f7fe1f5eab010191aa4570f27641876fa1267 upstream.

Add __GFP_ZERO flag for alloc_page in function bio_copy_kern to initialize
the buffer of a bio.

Signed-off-by: Haimin Zhang <tcs.kernel@gmail.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220216084038.15635-1-tcs.kernel@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[nobelbarakat: Backported to 5.4: Manually added __GFP_ZERO flag]
Signed-off-by: Nobel Barakat <nobelbarakat@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/block/bio.c b/block/bio.c
index 1c52d0196e15c69c74583af8add87f504561eb4c..40004a3631a803047940aabe955d3affdf1cdb91 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -1627,7 +1627,7 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
                if (bytes > len)
                        bytes = len;
 
-               page = alloc_page(q->bounce_gfp | gfp_mask);
+               page = alloc_page(q->bounce_gfp | __GFP_ZERO | gfp_mask);
                if (!page)
                        goto cleanup;