Commit 0c7bfc32 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Kevin Wolf
Browse files

vdi: move end-of-I/O handling at the end 



The next step is to take code that only triggers after the first operation,
and move it at the end of vdi_aio_read_cb and vdi_aio_write_cb.

Acked-by: default avatarStefan Weil <sw@weilnetz.de>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 3d46a75a

block/vdi.c

+56 −67
Original line number Diff line number Diff line
@@ -533,20 +533,7 @@ static int vdi_aio_read_cb(void *opaque, int ret) 
    uint32_t sector_in_block;

    uint32_t n_sectors;



    logout("%u sectors read\n", acb->n_sectors);



restart:

    acb->nb_sectors -= acb->n_sectors;



    if (acb->nb_sectors == 0) {

        /* request completed */

        ret = 0;

        goto done;

    }



    acb->sector_num += acb->n_sectors;

    acb->buf += acb->n_sectors * SECTOR_SIZE;



    block_index = acb->sector_num / s->block_sectors;

    sector_in_block = acb->sector_num % s->block_sectors;

    n_sectors = s->block_sectors - sector_in_block;
@@ -573,11 +560,16 @@ restart: 
        qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);

        ret = bdrv_co_readv(bs->file, offset, n_sectors, &acb->hd_qiov);

    }

    if (ret >= 0) {

    logout("%u sectors read\n", acb->n_sectors);



    acb->nb_sectors -= acb->n_sectors;

    acb->sector_num += acb->n_sectors;

    acb->buf += acb->n_sectors * SECTOR_SIZE;



    if (ret >= 0 && acb->nb_sectors > 0) {

        goto restart;

    }



done:

    if (acb->qiov->niov > 1) {

        qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);

        qemu_vfree(acb->orig_buf);
@@ -609,56 +601,6 @@ static int vdi_aio_write_cb(void *opaque, int ret) 
    uint32_t n_sectors;



restart:

    acb->nb_sectors -= acb->n_sectors;

    acb->sector_num += acb->n_sectors;

    acb->buf += acb->n_sectors * SECTOR_SIZE;



    if (acb->nb_sectors == 0) {

        logout("finished data write\n");

        acb->n_sectors = 0;

        ret = 0;

        if (acb->header_modified) {

            VdiHeader *header = acb->block_buffer;

            logout("now writing modified header\n");

            assert(VDI_IS_ALLOCATED(acb->bmap_first));

            *header = s->header;

            vdi_header_to_le(header);

            acb->header_modified = 0;

            acb->hd_iov.iov_base = acb->block_buffer;

            acb->hd_iov.iov_len = SECTOR_SIZE;

            qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);

            ret = bdrv_co_writev(bs->file, 0, 1, &acb->hd_qiov);

        }

        if (ret >= 0 && VDI_IS_ALLOCATED(acb->bmap_first)) {

            /* One or more new blocks were allocated. */

            uint64_t offset;

            uint32_t bmap_first;

            uint32_t bmap_last;

            g_free(acb->block_buffer);

            acb->block_buffer = NULL;

            bmap_first = acb->bmap_first;

            bmap_last = acb->bmap_last;

            logout("now writing modified block map entry %u...%u\n",

                   bmap_first, bmap_last);

            /* Write modified sectors from block map. */

            bmap_first /= (SECTOR_SIZE / sizeof(uint32_t));

            bmap_last /= (SECTOR_SIZE / sizeof(uint32_t));

            n_sectors = bmap_last - bmap_first + 1;

            offset = s->bmap_sector + bmap_first;

            acb->bmap_first = VDI_UNALLOCATED;

            acb->hd_iov.iov_base = (void *)((uint8_t *)&s->bmap[0] +

                                            bmap_first * SECTOR_SIZE);

            acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE;

            qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);

            logout("will write %u block map sectors starting from entry %u\n",

                   n_sectors, bmap_first);

            ret = bdrv_co_writev(bs->file, offset, n_sectors, &acb->hd_qiov);

        }

        goto done;

    }



    logout("%u sectors written\n", acb->n_sectors);



    block_index = acb->sector_num / s->block_sectors;

    sector_in_block = acb->sector_num % s->block_sectors;

    n_sectors = s->block_sectors - sector_in_block;
@@ -709,11 +651,58 @@ restart: 
        qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);

        ret = bdrv_co_writev(bs->file, offset, n_sectors, &acb->hd_qiov);

    }

    if (ret >= 0) {



    acb->nb_sectors -= acb->n_sectors;

    acb->sector_num += acb->n_sectors;

    acb->buf += acb->n_sectors * SECTOR_SIZE;



    logout("%u sectors written\n", acb->n_sectors);

    if (ret >= 0 && acb->nb_sectors > 0) {

        goto restart;

    }



done:

    logout("finished data write\n");

    if (ret >= 0) {

        ret = 0;

        if (acb->header_modified) {

            VdiHeader *header = acb->block_buffer;

            logout("now writing modified header\n");

            assert(VDI_IS_ALLOCATED(acb->bmap_first));

            *header = s->header;

            vdi_header_to_le(header);

            acb->header_modified = 0;

            acb->hd_iov.iov_base = acb->block_buffer;

            acb->hd_iov.iov_len = SECTOR_SIZE;

            qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);

            ret = bdrv_co_writev(bs->file, 0, 1, &acb->hd_qiov);

        }

        if (ret >= 0 && VDI_IS_ALLOCATED(acb->bmap_first)) {

            /* One or more new blocks were allocated. */

            uint64_t offset;

            uint32_t bmap_first;

            uint32_t bmap_last;

            g_free(acb->block_buffer);

            acb->block_buffer = NULL;

            bmap_first = acb->bmap_first;

            bmap_last = acb->bmap_last;

            logout("now writing modified block map entry %u...%u\n",

                   bmap_first, bmap_last);

            /* Write modified sectors from block map. */

            bmap_first /= (SECTOR_SIZE / sizeof(uint32_t));

            bmap_last /= (SECTOR_SIZE / sizeof(uint32_t));

            n_sectors = bmap_last - bmap_first + 1;

            offset = s->bmap_sector + bmap_first;

            acb->bmap_first = VDI_UNALLOCATED;

            acb->hd_iov.iov_base = (void *)((uint8_t *)&s->bmap[0] +

                                            bmap_first * SECTOR_SIZE);

            acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE;

            qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);

            logout("will write %u block map sectors starting from entry %u\n",

                   n_sectors, bmap_first);

            ret = bdrv_co_writev(bs->file, offset, n_sectors, &acb->hd_qiov);

        }

    }



    if (acb->qiov->niov > 1) {

        qemu_vfree(acb->orig_buf);

    }