lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 18 Jun 2012 13:21:08 +0300 From: "Michael S. Tsirkin" <mst@...hat.com> To: Asias He <asias@...hat.com> Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, virtualization@...ts.linux-foundation.org, Rusty Russell <rusty@...tcorp.com.au>, Christoph Hellwig <hch@....de>, Minchan Kim <minchan.kim@...il.com> Subject: Re: [PATCH 3/3] virtio-blk: Add bio-based IO path for virtio-blk On Mon, Jun 18, 2012 at 02:53:10PM +0800, Asias He wrote: > +static void virtblk_make_request(struct request_queue *q, struct bio *bio) > +{ > + struct virtio_blk *vblk = q->queuedata; > + unsigned int num, out = 0, in = 0; > + struct virtblk_req *vbr; > + > + BUG_ON(bio->bi_phys_segments + 2 > vblk->sg_elems); > + BUG_ON(bio->bi_rw & (REQ_FLUSH | REQ_FUA)); > + > + vbr = virtblk_alloc_req(vblk, GFP_NOIO); > + if (!vbr) { > + bio_endio(bio, -ENOMEM); > + return; > + } > + > + vbr->bio = bio; > + vbr->req = NULL; > + vbr->out_hdr.type = 0; > + vbr->out_hdr.sector = bio->bi_sector; > + vbr->out_hdr.ioprio = bio_prio(bio); > + > + sg_set_buf(&vbr->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); > + > + num = blk_bio_map_sg(q, bio, vbr->sg + out); > + > + sg_set_buf(&vbr->sg[num + out + in++], &vbr->status, > + sizeof(vbr->status)); > + > + if (num) { > + if (bio->bi_rw & REQ_WRITE) { > + vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; > + out += num; > + } else { > + vbr->out_hdr.type |= VIRTIO_BLK_T_IN; > + in += num; > + } > + } > + > + spin_lock_irq(vblk->disk->queue->queue_lock); > + if (virtqueue_add_buf(vblk->vq, vbr->sg, out, in, vbr, > + GFP_ATOMIC) < 0) { > + spin_unlock_irq(vblk->disk->queue->queue_lock); Any implications of dropping lock like that? E.g. for suspend. like we are still discussing with unlocked kick? > + virtblk_add_buf_wait(vblk, vbr, out, in); > + } else { > + virtqueue_kick(vblk->vq); Why special case the first call? task state manipulation so expensive? > + spin_unlock_irq(vblk->disk->queue->queue_lock); > + } > +} > + -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists