Commit b5772fdd authored by Eric Blake's avatar Eric Blake Committed by Kevin Wolf
Browse files

virtio: Switch to byte-based aio block access 



Sector-based blk_aio_readv() and blk_aio_writev() should die; switch
to byte-based blk_aio_preadv() and blk_aio_pwritev() instead.

The trace is modified at the same time, and nb_sectors is now
unused.  Fix a comment typo while in the vicinity.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 03c90063

hw/block/virtio-blk.c

+8 −10
Original line number Diff line number Diff line
@@ -322,7 +322,6 @@ static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb, 
{

    QEMUIOVector *qiov = &mrb->reqs[start]->qiov;

    int64_t sector_num = mrb->reqs[start]->sector_num;

    int nb_sectors = mrb->reqs[start]->qiov.size / BDRV_SECTOR_SIZE;

    bool is_write = mrb->is_write;



    if (num_reqs > 1) {
@@ -331,7 +330,7 @@ static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb, 
        int tmp_niov = qiov->niov;



        /* mrb->reqs[start]->qiov was initialized from external so we can't

         * modifiy it here. We need to initialize it locally and then add the

         * modify it here. We need to initialize it locally and then add the

         * external iovecs. */

        qemu_iovec_init(qiov, niov);
@@ -343,22 +342,21 @@ static inline void submit_requests(BlockBackend *blk, MultiReqBuffer *mrb, 
            qemu_iovec_concat(qiov, &mrb->reqs[i]->qiov, 0,

                              mrb->reqs[i]->qiov.size);

            mrb->reqs[i - 1]->mr_next = mrb->reqs[i];

            nb_sectors += mrb->reqs[i]->qiov.size / BDRV_SECTOR_SIZE;

        }

        assert(nb_sectors == qiov->size / BDRV_SECTOR_SIZE);



        trace_virtio_blk_submit_multireq(mrb, start, num_reqs, sector_num,

                                         nb_sectors, is_write);

        trace_virtio_blk_submit_multireq(mrb, start, num_reqs,

                                         sector_num << BDRV_SECTOR_BITS,

                                         qiov->size, is_write);

        block_acct_merge_done(blk_get_stats(blk),

                              is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ,

                              num_reqs - 1);

    }



    if (is_write) {

        blk_aio_writev(blk, sector_num, qiov, nb_sectors,

        blk_aio_pwritev(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0,

                        virtio_blk_rw_complete, mrb->reqs[start]);

    } else {

        blk_aio_readv(blk, sector_num, qiov, nb_sectors,

        blk_aio_preadv(blk, sector_num << BDRV_SECTOR_BITS, qiov, 0,

                       virtio_blk_rw_complete, mrb->reqs[start]);

    }

}

trace-events

+1 −1
Original line number Diff line number Diff line
@@ -118,7 +118,7 @@ virtio_blk_req_complete(void *req, int status) "req %p status %d" 
virtio_blk_rw_complete(void *req, int ret) "req %p ret %d"

virtio_blk_handle_write(void *req, uint64_t sector, size_t nsectors) "req %p sector %"PRIu64" nsectors %zu"

virtio_blk_handle_read(void *req, uint64_t sector, size_t nsectors) "req %p sector %"PRIu64" nsectors %zu"

virtio_blk_submit_multireq(void *mrb, int start, int num_reqs, uint64_t sector, size_t nsectors, bool is_write) "mrb %p start %d num_reqs %d sector %"PRIu64" nsectors %zu is_write %d"

virtio_blk_submit_multireq(void *mrb, int start, int num_reqs, uint64_t offset, size_t size, bool is_write) "mrb %p start %d num_reqs %d offset %"PRIu64" size %zu is_write %d"



# hw/block/dataplane/virtio-blk.c

virtio_blk_data_plane_start(void *s) "dataplane %p"