Commit 1acc3466 authored by Vladimir Sementsov-Ogievskiy's avatar Vladimir Sementsov-Ogievskiy Committed by Stefan Hajnoczi
Browse files

block/io: introduce bdrv_co_p{read, write}v_part 



Introduce extended variants of bdrv_co_preadv and bdrv_co_pwritev
with qiov_offset parameter.

Signed-off-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-10-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-10-vsementsov@virtuozzo.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 28c4da28

block/io.c

+23 −6
Original line number Diff line number Diff line
@@ -1614,7 +1614,8 @@ static void bdrv_padding_destroy(BdrvRequestPadding *pad) 
 *

 * Function always succeeds.

 */

static bool bdrv_pad_request(BlockDriverState *bs, QEMUIOVector **qiov,

static bool bdrv_pad_request(BlockDriverState *bs,

                             QEMUIOVector **qiov, size_t *qiov_offset,

                             int64_t *offset, unsigned int *bytes,

                             BdrvRequestPadding *pad)

{
@@ -1623,11 +1624,12 @@ static bool bdrv_pad_request(BlockDriverState *bs, QEMUIOVector **qiov, 
    }



    qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head,

                             *qiov, 0, *bytes,

                             *qiov, *qiov_offset, *bytes,

                             pad->buf + pad->buf_len - pad->tail, pad->tail);

    *bytes += pad->head + pad->tail;

    *offset -= pad->head;

    *qiov = &pad->local_qiov;

    *qiov_offset = 0;



    return true;

}
@@ -1635,6 +1637,14 @@ static bool bdrv_pad_request(BlockDriverState *bs, QEMUIOVector **qiov, 
int coroutine_fn bdrv_co_preadv(BdrvChild *child,

    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,

    BdrvRequestFlags flags)

{

    return bdrv_co_preadv_part(child, offset, bytes, qiov, 0, flags);

}



int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,

    int64_t offset, unsigned int bytes,

    QEMUIOVector *qiov, size_t qiov_offset,

    BdrvRequestFlags flags)

{

    BlockDriverState *bs = child->bs;

    BdrvTrackedRequest req;
@@ -1655,12 +1665,12 @@ int coroutine_fn bdrv_co_preadv(BdrvChild *child, 
        flags |= BDRV_REQ_COPY_ON_READ;

    }



    bdrv_pad_request(bs, &qiov, &offset, &bytes, &pad);

    bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad);



    tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ);

    ret = bdrv_aligned_preadv(child, &req, offset, bytes,

                              bs->bl.request_alignment,

                              qiov, 0, flags);

                              qiov, qiov_offset, flags);

    tracked_request_end(&req);

    bdrv_dec_in_flight(bs);
@@ -2023,6 +2033,13 @@ out: 
int coroutine_fn bdrv_co_pwritev(BdrvChild *child,

    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,

    BdrvRequestFlags flags)

{

    return bdrv_co_pwritev_part(child, offset, bytes, qiov, 0, flags);

}



int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,

    int64_t offset, unsigned int bytes, QEMUIOVector *qiov, size_t qiov_offset,

    BdrvRequestFlags flags)

{

    BlockDriverState *bs = child->bs;

    BdrvTrackedRequest req;
@@ -2054,14 +2071,14 @@ int coroutine_fn bdrv_co_pwritev(BdrvChild *child, 
        goto out;

    }



    if (bdrv_pad_request(bs, &qiov, &offset, &bytes, &pad)) {

    if (bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad)) {

        mark_request_serialising(&req, align);

        wait_serialising_requests(&req);

        bdrv_padding_rmw_read(child, &req, &pad, false);

    }



    ret = bdrv_aligned_pwritev(child, &req, offset, bytes, align,

                               qiov, 0, flags);

                               qiov, qiov_offset, flags);



    bdrv_padding_destroy(&pad);

include/block/block_int.h

+6 −0
Original line number Diff line number Diff line
@@ -959,9 +959,15 @@ extern BlockDriver bdrv_qcow2; 
int coroutine_fn bdrv_co_preadv(BdrvChild *child,

    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,

    BdrvRequestFlags flags);

int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,

    int64_t offset, unsigned int bytes,

    QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);

int coroutine_fn bdrv_co_pwritev(BdrvChild *child,

    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,

    BdrvRequestFlags flags);

int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,

    int64_t offset, unsigned int bytes,

    QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags);



static inline int coroutine_fn bdrv_co_pread(BdrvChild *child,

    int64_t offset, unsigned int bytes, void *buf, BdrvRequestFlags flags)