| Message ID | 1360671815-2135-5-git-send-email-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 02/12/2013 08:23 PM, Paolo Bonzini wrote: > This is similar to the previous patch, but a bit more radical > because the bio and req paths now share the buffer construction > code. Because the req path doesn't use vbr->sg, however, we > need to add a couple of arguments to __virtblk_add_req. > > We also need to teach __virtblk_add_req how to build SCSI command > requests. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > drivers/block/virtio_blk.c | 74 ++++++++++++++++++++++--------------------- > 1 files changed, 38 insertions(+), 36 deletions(-) > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index 4a31fcc..22deb65 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c > @@ -102,18 +102,26 @@ static inline struct virtblk_req *virtblk_alloc_req(struct virtio_blk *vblk, > } > > static int __virtblk_add_req(struct virtqueue *vq, > - struct virtblk_req *vbr) > + struct virtblk_req *vbr, > + struct scatterlist *data_sg, > + unsigned data_nents) > { > struct scatterlist sg; > enum dma_data_direction dir; > int ret; > > + int type = vbr->out_hdr.type & ~VIRTIO_BLK_T_OUT; > unsigned int nents = 2; > unsigned int nsg = 2; > > - if (vbr->nents) { > + if (type == VIRTIO_BLK_T_SCSI_CMD) { > + BUG_ON(use_bio); Do we really need the BUG_ON? Even if with use_bio=1, VIRTIO_BLK_T_SCSI_CMD cmd can be fired. See this: # cat /proc/cmdline root=/dev/mapper/rhel-root console=ttyS0 virtio_blk.use_bio=1 # sg_inq /dev/vda [ 36.042300] ------------[ cut here ]------------ [ 36.043021] kernel BUG at drivers/block/virtio_blk.c:118! [ 36.043021] invalid opcode: 0000 [#1] SMP [ 36.043021] Modules linked in: [ 36.043021] CPU 2 [ 36.043021] Pid: 3311, comm: sg_inq Not tainted 3.8.0-rc7+ #618 Bochs Bochs [ 36.043021] RIP: 0010:[<ffffffff816d740d>] [<ffffffff816d740d>] __virtblk_add_req+0x1cd/0x1e0 [ 36.043021] RSP: 0018:ffff88007b59b9d8 EFLAGS: 00010002 [ 36.043021] RAX: 0000000000000001 RBX: 0000000000000002 RCX: 0000000000000002 [ 36.043021] RDX: 0000000000000002 RSI: ffff88007a430000 RDI: ffff88007b422000 [ 36.043021] RBP: ffff88007b59ba28 R08: ffff88007b59b9e0 R09: ffff88007b59b9f4 [ 36.043021] R10: 0000000000000001 R11: ffff88007bf57900 R12: ffff88007a430000 [ 36.043021] R13: ffff88007b422000 R14: 0000000000000001 R15: ffff880077d34088 [ 36.043021] FS: 00007eff2efcb740(0000) GS:ffff88007eb00000(0000) knlGS:0000000000000000 [ 36.043021] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.043021] CR2: 0000003f33e0f200 CR3: 000000007f023000 CR4: 00000000000006e0 [ 36.043021] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 36.043021] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 36.043021] Process sg_inq (pid: 3311, threadinfo ffff88007b59a000, task ffff88007f47a3f0) [ 36.043021] Stack: [ 36.043021] ffff88007b59ba40 ffff880077d34088 ffff88007bf57980 0000000100000001 [ 36.043021] ffff88007fffa6c0 ffff88007a430000 ffff88007f66abc0 ffff880077d34000 [ 36.043021] ffff88007bdab410 0000000000000000 ffff88007b59ba78 ffffffff816d7f6c [ 36.043021] Call Trace: [ 36.043021] [<ffffffff816d7f6c>] virtblk_request+0xec/0x1c0 [ 36.043021] [<ffffffff8148b947>] __blk_run_queue+0x37/0x50 [ 36.043021] [<ffffffff81486c10>] __elv_add_request+0xb0/0x230 [ 36.043021] [<ffffffff81491c69>] blk_execute_rq_nowait+0x79/0x100 [ 36.043021] [<ffffffff811f06e1>] ? bio_phys_segments+0x21/0x30 [ 36.043021] [<ffffffff81491d5d>] blk_execute_rq+0x6d/0xf0 [ 36.043021] [<ffffffff81491798>] ? blk_rq_append_bio+0x28/0x70 [ 36.043021] [<ffffffff81491ad0>] ? blk_rq_map_user+0x1a0/0x280 [ 36.043021] [<ffffffff814979c4>] sg_io+0x274/0x3e0 [ 36.043021] [<ffffffff81497f15>] scsi_cmd_ioctl+0x3e5/0x460 [ 36.043021] [<ffffffff8118c816>] ? handle_pte_fault+0xf6/0x9c0 [ 36.043021] [<ffffffff8116e8e0>] ? release_pages+0x190/0x1e0 [ 36.043021] [<ffffffff81497fe1>] scsi_cmd_blk_ioctl+0x51/0x70 [ 36.043021] [<ffffffff816d80ac>] virtblk_ioctl+0x6c/0x90 [ 36.043021] [<ffffffff81494068>] __blkdev_driver_ioctl+0x28/0x30 [ 36.043021] [<ffffffff814946d0>] blkdev_ioctl+0x200/0x7b0 [ 36.043021] [<ffffffff811c0836>] ? cp_new_stat+0x116/0x130 [ 36.043021] [<ffffffff811f232c>] block_ioctl+0x3c/0x40 [ 36.043021] [<ffffffff811cceaa>] do_vfs_ioctl+0x9a/0x550 [ 36.043021] [<ffffffff811cd3b7>] sys_ioctl+0x57/0x90 [ 36.043021] [<ffffffff814b7c4e>] ? trace_hardirqs_on_thunk+0x3a/0x3c [ 36.043021] [<ffffffff81c6ad99>] system_call_fastpath+0x16/0x1b [ 36.043021] Code: 24 20 48 8d 7d b0 ba 10 00 00 00 e8 2e 3d de ff 48 8d 75 b0 b9 02 00 00 00 ba 01 00 00 00 4c 89 ef e8 88 bb e6 ff e9 d9 fe ff ff <0f> 0b eb fe 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 [ 36.043021] RIP [<ffffffff816d740d>] __virtblk_add_req+0x1cd/0x1e0 [ 36.043021] RSP <ffff88007b59b9d8> [ 36.043021] ---[ end trace 93ac0a3ba2789369 ]--- > + nsg += 3; > + nents += 3; > + } > + if (data_nents) { > nsg++; > - nents += vbr->nents; > + nents += data_nents; > } > > ret = virtqueue_start_buf(vq, vbr, nents, nsg, GFP_ATOMIC); > @@ -124,14 +132,32 @@ static int __virtblk_add_req(struct virtqueue *vq, > sg_init_one(&sg, &vbr->out_hdr, sizeof(vbr->out_hdr)); > virtqueue_add_sg(vq, &sg, 1, dir); > > - if (vbr->nents) { > + /* > + * If this is a packet command we need a couple of additional headers. > + * Behind the normal outhdr we put a segment with the scsi command > + * block, and before the normal inhdr we put the sense data and the > + * inhdr with additional status information. > + */ > + if (type == VIRTIO_BLK_T_SCSI_CMD) { > + sg_init_one(&sg, vbr->req->cmd, vbr->req->cmd_len); > + virtqueue_add_sg(vq, &sg, 1, dir); > + } > + > + if (data_nents) { > if ((vbr->out_hdr.type & VIRTIO_BLK_T_OUT) == 0) > dir = DMA_FROM_DEVICE; > > - virtqueue_add_sg(vq, vbr->sg, vbr->nents, dir); > + virtqueue_add_sg(vq, data_sg, data_nents, dir); > } > > dir = DMA_FROM_DEVICE; > + if (type == VIRTIO_BLK_T_SCSI_CMD) { > + sg_init_one(&sg, vbr->req->sense, SCSI_SENSE_BUFFERSIZE); > + virtqueue_add_sg(vq, &sg, 1, dir); > + sg_init_one(&sg, &vbr->in_hdr, sizeof(vbr->in_hdr)); > + virtqueue_add_sg(vq, &sg, 1, dir); > + } > + > sg_init_one(&sg, &vbr->status, sizeof(vbr->status)); > virtqueue_add_sg(vq, &sg, 1, dir); > > @@ -146,7 +172,8 @@ static void virtblk_add_req(struct virtblk_req *vbr) > int ret; > > spin_lock_irq(vblk->disk->queue->queue_lock); > - while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr)) < 0)) { > + while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr, vbr->sg, > + vbr->nents)) < 0)) { > prepare_to_wait_exclusive(&vblk->queue_wait, &wait, > TASK_UNINTERRUPTIBLE); > > @@ -299,7 +326,7 @@ static void virtblk_done(struct virtqueue *vq) > static bool do_req(struct request_queue *q, struct virtio_blk *vblk, > struct request *req) > { > - unsigned long num, out = 0, in = 0; > + unsigned int num; > struct virtblk_req *vbr; > > vbr = virtblk_alloc_req(vblk, GFP_ATOMIC); > @@ -336,40 +363,15 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, > } > } > > - sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); > - > - /* > - * If this is a packet command we need a couple of additional headers. > - * Behind the normal outhdr we put a segment with the scsi command > - * block, and before the normal inhdr we put the sense data and the > - * inhdr with additional status information before the normal inhdr. > - */ > - if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC) > - sg_set_buf(&vblk->sg[out++], vbr->req->cmd, vbr->req->cmd_len); > - > - num = blk_rq_map_sg(q, vbr->req, vblk->sg + out); > - > - if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC) { > - sg_set_buf(&vblk->sg[num + out + in++], vbr->req->sense, SCSI_SENSE_BUFFERSIZE); > - sg_set_buf(&vblk->sg[num + out + in++], &vbr->in_hdr, > - sizeof(vbr->in_hdr)); > - } > - > - sg_set_buf(&vblk->sg[num + out + in++], &vbr->status, > - sizeof(vbr->status)); > - > + num = blk_rq_map_sg(q, vbr->req, vblk->sg); > if (num) { > - if (rq_data_dir(vbr->req) == WRITE) { > + if (rq_data_dir(vbr->req) == WRITE) > vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; > - out += num; > - } else { > + else > vbr->out_hdr.type |= VIRTIO_BLK_T_IN; > - in += num; > - } > } > > - if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr, > - GFP_ATOMIC) < 0) { > + if (__virtblk_add_req(vblk->vq, vbr, vblk->sg, num) < 0) { > mempool_free(vbr, vblk->pool); > return false; > } >
Il 17/02/2013 07:37, Asias He ha scritto: >> > static int __virtblk_add_req(struct virtqueue *vq, >> > - struct virtblk_req *vbr) >> > + struct virtblk_req *vbr, >> > + struct scatterlist *data_sg, >> > + unsigned data_nents) >> > { >> > struct scatterlist sg; >> > enum dma_data_direction dir; >> > int ret; >> > >> > + int type = vbr->out_hdr.type & ~VIRTIO_BLK_T_OUT; >> > unsigned int nents = 2; >> > unsigned int nsg = 2; >> > >> > - if (vbr->nents) { >> > + if (type == VIRTIO_BLK_T_SCSI_CMD) { >> > + BUG_ON(use_bio); > Do we really need the BUG_ON? Even if with use_bio=1, > VIRTIO_BLK_T_SCSI_CMD cmd can be fired. See this: I stand corrected... will send the patch with this removed. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 4a31fcc..22deb65 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -102,18 +102,26 @@ static inline struct virtblk_req *virtblk_alloc_req(struct virtio_blk *vblk, } static int __virtblk_add_req(struct virtqueue *vq, - struct virtblk_req *vbr) + struct virtblk_req *vbr, + struct scatterlist *data_sg, + unsigned data_nents) { struct scatterlist sg; enum dma_data_direction dir; int ret; + int type = vbr->out_hdr.type & ~VIRTIO_BLK_T_OUT; unsigned int nents = 2; unsigned int nsg = 2; - if (vbr->nents) { + if (type == VIRTIO_BLK_T_SCSI_CMD) { + BUG_ON(use_bio); + nsg += 3; + nents += 3; + } + if (data_nents) { nsg++; - nents += vbr->nents; + nents += data_nents; } ret = virtqueue_start_buf(vq, vbr, nents, nsg, GFP_ATOMIC); @@ -124,14 +132,32 @@ static int __virtblk_add_req(struct virtqueue *vq, sg_init_one(&sg, &vbr->out_hdr, sizeof(vbr->out_hdr)); virtqueue_add_sg(vq, &sg, 1, dir); - if (vbr->nents) { + /* + * If this is a packet command we need a couple of additional headers. + * Behind the normal outhdr we put a segment with the scsi command + * block, and before the normal inhdr we put the sense data and the + * inhdr with additional status information. + */ + if (type == VIRTIO_BLK_T_SCSI_CMD) { + sg_init_one(&sg, vbr->req->cmd, vbr->req->cmd_len); + virtqueue_add_sg(vq, &sg, 1, dir); + } + + if (data_nents) { if ((vbr->out_hdr.type & VIRTIO_BLK_T_OUT) == 0) dir = DMA_FROM_DEVICE; - virtqueue_add_sg(vq, vbr->sg, vbr->nents, dir); + virtqueue_add_sg(vq, data_sg, data_nents, dir); } dir = DMA_FROM_DEVICE; + if (type == VIRTIO_BLK_T_SCSI_CMD) { + sg_init_one(&sg, vbr->req->sense, SCSI_SENSE_BUFFERSIZE); + virtqueue_add_sg(vq, &sg, 1, dir); + sg_init_one(&sg, &vbr->in_hdr, sizeof(vbr->in_hdr)); + virtqueue_add_sg(vq, &sg, 1, dir); + } + sg_init_one(&sg, &vbr->status, sizeof(vbr->status)); virtqueue_add_sg(vq, &sg, 1, dir); @@ -146,7 +172,8 @@ static void virtblk_add_req(struct virtblk_req *vbr) int ret; spin_lock_irq(vblk->disk->queue->queue_lock); - while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr)) < 0)) { + while (unlikely((ret = __virtblk_add_req(vblk->vq, vbr, vbr->sg, + vbr->nents)) < 0)) { prepare_to_wait_exclusive(&vblk->queue_wait, &wait, TASK_UNINTERRUPTIBLE); @@ -299,7 +326,7 @@ static void virtblk_done(struct virtqueue *vq) static bool do_req(struct request_queue *q, struct virtio_blk *vblk, struct request *req) { - unsigned long num, out = 0, in = 0; + unsigned int num; struct virtblk_req *vbr; vbr = virtblk_alloc_req(vblk, GFP_ATOMIC); @@ -336,40 +363,15 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, } } - sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr)); - - /* - * If this is a packet command we need a couple of additional headers. - * Behind the normal outhdr we put a segment with the scsi command - * block, and before the normal inhdr we put the sense data and the - * inhdr with additional status information before the normal inhdr. - */ - if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC) - sg_set_buf(&vblk->sg[out++], vbr->req->cmd, vbr->req->cmd_len); - - num = blk_rq_map_sg(q, vbr->req, vblk->sg + out); - - if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC) { - sg_set_buf(&vblk->sg[num + out + in++], vbr->req->sense, SCSI_SENSE_BUFFERSIZE); - sg_set_buf(&vblk->sg[num + out + in++], &vbr->in_hdr, - sizeof(vbr->in_hdr)); - } - - sg_set_buf(&vblk->sg[num + out + in++], &vbr->status, - sizeof(vbr->status)); - + num = blk_rq_map_sg(q, vbr->req, vblk->sg); if (num) { - if (rq_data_dir(vbr->req) == WRITE) { + if (rq_data_dir(vbr->req) == WRITE) vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; - out += num; - } else { + else vbr->out_hdr.type |= VIRTIO_BLK_T_IN; - in += num; - } } - if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr, - GFP_ATOMIC) < 0) { + if (__virtblk_add_req(vblk->vq, vbr, vblk->sg, num) < 0) { mempool_free(vbr, vblk->pool); return false; }
This is similar to the previous patch, but a bit more radical because the bio and req paths now share the buffer construction code. Because the req path doesn't use vbr->sg, however, we need to add a couple of arguments to __virtblk_add_req. We also need to teach __virtblk_add_req how to build SCSI command requests. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- drivers/block/virtio_blk.c | 74 ++++++++++++++++++++++--------------------- 1 files changed, 38 insertions(+), 36 deletions(-)