Commit cff86b38 authored by Eric Blake's avatar Eric Blake Committed by Kevin Wolf
Browse files

block: Tighter assertions on bdrv_aligned_pwritev() 



For symmetry with bdrv_aligned_preadv(), assert that the caller
really has aligned things properly. This requires adding an align
parameter, which is used now only in the new asserts, but will
come in handy in a later patch that adds auto-fragmentation to the
max transfer size, since that value need not always be a multiple
of the alignment, and therefore must be rounded down.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent cfef6a45

block/io.c

+8 −5
Original line number Diff line number Diff line
@@ -1254,7 +1254,7 @@ fail: 
 */

static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,

    BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,

    QEMUIOVector *qiov, int flags)

    int64_t align, QEMUIOVector *qiov, int flags)

{

    BlockDriver *drv = bs->drv;

    bool waited;
@@ -1263,6 +1263,9 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, 
    int64_t start_sector = offset >> BDRV_SECTOR_BITS;

    int64_t end_sector = DIV_ROUND_UP(offset + bytes, BDRV_SECTOR_SIZE);



    assert(is_power_of_2(align));

    assert((offset & (align - 1)) == 0);

    assert((bytes & (align - 1)) == 0);

    assert(!qiov || bytes == qiov->size);

    assert((bs->open_flags & BDRV_O_NO_IO) == 0);

    assert(!(flags & ~BDRV_REQ_MASK));
@@ -1349,7 +1352,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, 


        memset(buf + head_padding_bytes, 0, zero_bytes);

        ret = bdrv_aligned_pwritev(bs, req, offset & ~(align - 1), align,

                                   &local_qiov,

                                   align, &local_qiov,

                                   flags & ~BDRV_REQ_ZERO_WRITE);

        if (ret < 0) {

            goto fail;
@@ -1362,7 +1365,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, 
    if (bytes >= align) {

        /* Write the aligned part in the middle. */

        uint64_t aligned_bytes = bytes & ~(align - 1);

        ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes,

        ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes, align,

                                   NULL, flags);

        if (ret < 0) {

            goto fail;
@@ -1386,7 +1389,7 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs, 
        bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);



        memset(buf, 0, bytes);

        ret = bdrv_aligned_pwritev(bs, req, offset, align,

        ret = bdrv_aligned_pwritev(bs, req, offset, align, align,

                                   &local_qiov, flags & ~BDRV_REQ_ZERO_WRITE);

    }

fail:
@@ -1511,7 +1514,7 @@ int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs, 
        bytes = ROUND_UP(bytes, align);

    }



    ret = bdrv_aligned_pwritev(bs, &req, offset, bytes,

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

                               use_local_qiov ? &local_qiov : qiov,

                               flags);