From: Christoph Hellwig Date: Thu, 28 Nov 2024 11:22:32 +0000 (+0530) Subject: block: copy back bounce buffer to user-space correctly in case of split X-Git-Tag: for-6.14/io_uring-20250118~35 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=031141976be0bd5f385775727a4ed3cc845eb7ba;p=linux-2.6-block.git block: copy back bounce buffer to user-space correctly in case of split Copy back the bounce buffer to user-space in entirety when the parent bio completes. The existing code uses bip_iter.bi_size for sizing the copy, which can be modified. So move away from that and fetch it from the vector passed to the block layer. While at it, switch to using better variable names. Fixes: 492c5d455969f ("block: bio-integrity: directly map user buffers") Signed-off-by: Christoph Hellwig Signed-off-by: Anuj Gupta Reviewed-by: Keith Busch Link: https://lore.kernel.org/r/20241128112240.8867-3-anuj20.g@samsung.com Signed-off-by: Jens Axboe --- diff --git a/block/bio-integrity.c b/block/bio-integrity.c index a448a25d13de..4341b0d4efa1 100644 --- a/block/bio-integrity.c +++ b/block/bio-integrity.c @@ -118,17 +118,18 @@ static void bio_integrity_unpin_bvec(struct bio_vec *bv, int nr_vecs, static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip) { - unsigned short nr_vecs = bip->bip_max_vcnt - 1; - struct bio_vec *copy = &bip->bip_vec[1]; - size_t bytes = bip->bip_iter.bi_size; - struct iov_iter iter; + unsigned short orig_nr_vecs = bip->bip_max_vcnt - 1; + struct bio_vec *orig_bvecs = &bip->bip_vec[1]; + struct bio_vec *bounce_bvec = &bip->bip_vec[0]; + size_t bytes = bounce_bvec->bv_len; + struct iov_iter orig_iter; int ret; - iov_iter_bvec(&iter, ITER_DEST, copy, nr_vecs, bytes); - ret = copy_to_iter(bvec_virt(bip->bip_vec), bytes, &iter); + iov_iter_bvec(&orig_iter, ITER_DEST, orig_bvecs, orig_nr_vecs, bytes); + ret = copy_to_iter(bvec_virt(bounce_bvec), bytes, &orig_iter); WARN_ON_ONCE(ret != bytes); - bio_integrity_unpin_bvec(copy, nr_vecs, true); + bio_integrity_unpin_bvec(orig_bvecs, orig_nr_vecs, true); } /**