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From:   Christoph Hellwig <hch@lst.de>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Pavel Begunkov <asml.silence@gmail.com>,
        Mike Snitzer <snitzer@redhat.com>,
        Ryusuke Konishi <konishi.ryusuke@gmail.com>,
        Konstantin Komarov <almaz.alexandrovich@paragon-software.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Md . Haris Iqbal " <haris.iqbal@ionos.com>,
        Jack Wang <jinpu.wang@ionos.com>,
        =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= <roger.pau@citrix.co>,
        Philipp Reisner <philipp.reisner@linbit.com>,
        Lars Ellenberg <lars.ellenberg@linbit.com>,
        linux-block@vger.kernel.org, dm-devel@redhat.com,
        linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
        linux-nilfs@vger.kernel.org, ntfs3@lists.linux.dev,
        xen-devel@lists.xenproject.org, drbd-dev@lists.linbit.com
Subject: [PATCH 12/19] xen-blkback: bio_alloc can't fail if it is allow to sleep
Date:   Mon, 24 Jan 2022 10:11:00 +0100
Message-Id: <20220124091107.642561-13-hch@lst.de>
In-Reply-To: <20220124091107.642561-1-hch@lst.de>
References: <20220124091107.642561-1-hch@lst.de>
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Precedence: bulk

Remove handling of NULL returns from sleeping bio_alloc calls given that
those can't fail.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/xen-blkback/blkback.c | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 14e452896d04c..6bb2ad7692065 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -1327,9 +1327,6 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
 				     seg[i].nsec << 9,
 				     seg[i].offset) == 0)) {
 			bio = bio_alloc(GFP_KERNEL, bio_max_segs(nseg - i));
-			if (unlikely(bio == NULL))
-				goto fail_put_bio;
-
 			biolist[nbio++] = bio;
 			bio_set_dev(bio, preq.bdev);
 			bio->bi_private = pending_req;
@@ -1346,9 +1343,6 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
 		BUG_ON(operation_flags != REQ_PREFLUSH);
 
 		bio = bio_alloc(GFP_KERNEL, 0);
-		if (unlikely(bio == NULL))
-			goto fail_put_bio;
-
 		biolist[nbio++] = bio;
 		bio_set_dev(bio, preq.bdev);
 		bio->bi_private = pending_req;
@@ -1381,14 +1375,6 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
 	free_req(ring, pending_req);
 	msleep(1); /* back off a bit */
 	return -EIO;
-
- fail_put_bio:
-	for (i = 0; i < nbio; i++)
-		bio_put(biolist[i]);
-	atomic_set(&pending_req->pendcnt, 1);
-	__end_block_io_op(pending_req, BLK_STS_RESOURCE);
-	msleep(1); /* back off a bit */
-	return -EIO;
 }
 
 
-- 
2.30.2