diff options
| -rw-r--r-- | hw/block/xen_disk.c | 42 |
1 files changed, 36 insertions, 6 deletions
diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 3a7dc194e2..456a2d5694 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 *)&ioreq->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 *)&ioreq->req; + if (!blk_split_discard(ioreq, req->sector_number, req->nr_sectors)) { + goto err; + } break; } default: |