Re: [Qemu-block] [PATCH v3] xen_disk: split discard input to match internal representation
On Wed, 23 Nov 2016, Olaf Hering wrote: > The guest sends discard requests as u64 sector/count pairs, but the > block layer operates internally with s64/s32 pairs. The conversion > leads to IO errors in the guest, the discard request is not processed. > > domU.cfg: > 'vdev=xvda, format=qcow2, backendtype=qdisk, target=/x.qcow2' > domU: > mkfs.ext4 -F /dev/xvda > Discarding device blocks: failed - Input/output error > > Fix this by splitting the request into chunks of BDRV_REQUEST_MAX_SECTORS. > Add input range checking to avoid overflow. > > Fixes f313520 ("xen_disk: add discard support") > > Signed-off-by: Olaf HeringReviewed-by: Stefano Stabellini > v3: > turn tab into spaces to fix checkpatch warning > v2: > adjust overflow check > add Fixes revspec because the initial commit also failed to convert u64 to > s32 > adjust summary > > hw/block/xen_disk.c | 42 -- > 1 file changed, 36 insertions(+), 6 deletions(-) > > diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c > index 3a7dc19..456a2d5 100644 > --- a/hw/block/xen_disk.c > +++ b/hw/block/xen_disk.c > @@ -660,6 +660,38 @@ static void qemu_aio_complete(void *opaque, int ret) > qemu_bh_schedule(ioreq->blkdev->bh); > } > > +static bool blk_split_discard(struct ioreq *ioreq, blkif_sector_t > sector_number, > + uint64_t nr_sectors) > +{ > +struct XenBlkDev *blkdev = ioreq->blkdev; > +int64_t byte_offset; > +int byte_chunk; > +uint64_t byte_remaining, limit; > +uint64_t sec_start = sector_number; > +uint64_t sec_count = nr_sectors; > + > +/* Wrap around, or overflowing byte limit? */ > +if (sec_start + sec_count < sec_count || > +sec_start + sec_count > INT64_MAX >> BDRV_SECTOR_BITS) { > +return false; > +} > + > +limit = BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS; > +byte_offset = sec_start << BDRV_SECTOR_BITS; > +byte_remaining = sec_count << BDRV_SECTOR_BITS; > + > +do { > +byte_chunk = byte_remaining > limit ? limit : byte_remaining; > +ioreq->aio_inflight++; > +blk_aio_pdiscard(blkdev->blk, byte_offset, byte_chunk, > + qemu_aio_complete, ioreq); > +byte_remaining -= byte_chunk; > +byte_offset += byte_chunk; > +} while (byte_remaining > 0); > + > +return true; > +} > + > static int ioreq_runio_qemu_aio(struct ioreq *ioreq) > { > struct XenBlkDev *blkdev = ioreq->blkdev; > @@ -708,12 +740,10 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq) > break; > case BLKIF_OP_DISCARD: > { > -struct blkif_request_discard *discard_req = (void *)>req; > -ioreq->aio_inflight++; > -blk_aio_pdiscard(blkdev->blk, > - discard_req->sector_number << BDRV_SECTOR_BITS, > - discard_req->nr_sectors << BDRV_SECTOR_BITS, > - qemu_aio_complete, ioreq); > +struct blkif_request_discard *req = (void *)>req; > +if (!blk_split_discard(ioreq, req->sector_number, req->nr_sectors)) { > +goto err; > +} > break; > } > default: >
Re: [Qemu-block] [PATCH v3] xen_disk: split discard input to match internal representation
On Wed, Nov 23, 2016 at 10:39:12AM +, Olaf Hering wrote: > The guest sends discard requests as u64 sector/count pairs, but the > block layer operates internally with s64/s32 pairs. The conversion > leads to IO errors in the guest, the discard request is not processed. > > domU.cfg: > 'vdev=xvda, format=qcow2, backendtype=qdisk, target=/x.qcow2' > domU: > mkfs.ext4 -F /dev/xvda > Discarding device blocks: failed - Input/output error > > Fix this by splitting the request into chunks of BDRV_REQUEST_MAX_SECTORS. > Add input range checking to avoid overflow. > > Fixes f313520 ("xen_disk: add discard support") > > Signed-off-by: Olaf HeringAcked-by: Anthony PERARD -- Anthony PERARD
[Qemu-block] [PATCH v3] xen_disk: split discard input to match internal representation
The guest sends discard requests as u64 sector/count pairs, but the block layer operates internally with s64/s32 pairs. The conversion leads to IO errors in the guest, the discard request is not processed. domU.cfg: 'vdev=xvda, format=qcow2, backendtype=qdisk, target=/x.qcow2' domU: mkfs.ext4 -F /dev/xvda Discarding device blocks: failed - Input/output error Fix this by splitting the request into chunks of BDRV_REQUEST_MAX_SECTORS. Add input range checking to avoid overflow. Fixes f313520 ("xen_disk: add discard support") Signed-off-by: Olaf Hering--- v3: turn tab into spaces to fix checkpatch warning v2: adjust overflow check add Fixes revspec because the initial commit also failed to convert u64 to s32 adjust summary hw/block/xen_disk.c | 42 -- 1 file changed, 36 insertions(+), 6 deletions(-) diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 3a7dc19..456a2d5 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -660,6 +660,38 @@ static void qemu_aio_complete(void *opaque, int ret) qemu_bh_schedule(ioreq->blkdev->bh); } +static bool blk_split_discard(struct ioreq *ioreq, blkif_sector_t sector_number, + uint64_t nr_sectors) +{ +struct XenBlkDev *blkdev = ioreq->blkdev; +int64_t byte_offset; +int byte_chunk; +uint64_t byte_remaining, limit; +uint64_t sec_start = sector_number; +uint64_t sec_count = nr_sectors; + +/* Wrap around, or overflowing byte limit? */ +if (sec_start + sec_count < sec_count || +sec_start + sec_count > INT64_MAX >> BDRV_SECTOR_BITS) { +return false; +} + +limit = BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS; +byte_offset = sec_start << BDRV_SECTOR_BITS; +byte_remaining = sec_count << BDRV_SECTOR_BITS; + +do { +byte_chunk = byte_remaining > limit ? limit : byte_remaining; +ioreq->aio_inflight++; +blk_aio_pdiscard(blkdev->blk, byte_offset, byte_chunk, + qemu_aio_complete, ioreq); +byte_remaining -= byte_chunk; +byte_offset += byte_chunk; +} while (byte_remaining > 0); + +return true; +} + static int ioreq_runio_qemu_aio(struct ioreq *ioreq) { struct XenBlkDev *blkdev = ioreq->blkdev; @@ -708,12 +740,10 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq) break; case BLKIF_OP_DISCARD: { -struct blkif_request_discard *discard_req = (void *)>req; -ioreq->aio_inflight++; -blk_aio_pdiscard(blkdev->blk, - discard_req->sector_number << BDRV_SECTOR_BITS, - discard_req->nr_sectors << BDRV_SECTOR_BITS, - qemu_aio_complete, ioreq); +struct blkif_request_discard *req = (void *)>req; +if (!blk_split_discard(ioreq, req->sector_number, req->nr_sectors)) { +goto err; +} break; } default: