Commit 9f0eb9e1 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

iscsi: Support BDRV_REQ_FUA 



This replaces the existing hack in the iscsi driver that sent the FUA
bit in writethrough mode and ignored the following flush in order to
optimise the number of roundtrips (see commit 73b5394e).

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
parent 93f5e6d8

block/iscsi.c

+14 −16
Original line number Diff line number Diff line
@@ -70,7 +70,6 @@ typedef struct IscsiLun { 
    bool lbprz;

    bool dpofua;

    bool has_write_same;

    bool force_next_flush;

    bool request_timed_out;

} IscsiLun;
@@ -84,7 +83,6 @@ typedef struct IscsiTask { 
    QEMUBH *bh;

    IscsiLun *iscsilun;

    QEMUTimer retry_timer;

    bool force_next_flush;

    int err_code;

} IscsiTask;
@@ -282,8 +280,6 @@ iscsi_co_generic_cb(struct iscsi_context *iscsi, int status, 
        }

        iTask->err_code = iscsi_translate_sense(&task->sense);

        error_report("iSCSI Failure: %s", iscsi_get_error(iscsi));

    } else {

        iTask->iscsilun->force_next_flush |= iTask->force_next_flush;

    }



out:
@@ -452,15 +448,15 @@ static void iscsi_allocationmap_clear(IscsiLun *iscsilun, int64_t sector_num, 
    }

}



static int coroutine_fn iscsi_co_writev(BlockDriverState *bs,

                                        int64_t sector_num, int nb_sectors,

                                        QEMUIOVector *iov)

static int coroutine_fn

iscsi_co_writev_flags(BlockDriverState *bs, int64_t sector_num, int nb_sectors,

                      QEMUIOVector *iov, int flags)

{

    IscsiLun *iscsilun = bs->opaque;

    struct IscsiTask iTask;

    uint64_t lba;

    uint32_t num_sectors;

    int fua;

    bool fua;



    if (!is_request_lun_aligned(sector_num, nb_sectors, iscsilun)) {

        return -EINVAL;
@@ -476,8 +472,7 @@ static int coroutine_fn iscsi_co_writev(BlockDriverState *bs, 
    num_sectors = sector_qemu2lun(nb_sectors, iscsilun);

    iscsi_co_init_iscsitask(iscsilun, &iTask);

retry:

    fua = iscsilun->dpofua && !bdrv_enable_write_cache(bs);

    iTask.force_next_flush = !fua;

    fua = iscsilun->dpofua && (flags & BDRV_REQ_FUA);

    if (iscsilun->use_16_for_rw) {

        iTask.task = iscsi_write16_task(iscsilun->iscsi, iscsilun->lun, lba,

                                        NULL, num_sectors * iscsilun->block_size,
@@ -518,6 +513,13 @@ retry: 
    return 0;

}



static int coroutine_fn

iscsi_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors,

                QEMUIOVector *iov)

{

    return iscsi_co_writev_flags(bs, sector_num, nb_sectors, iov, 0);

}





static bool iscsi_allocationmap_is_allocated(IscsiLun *iscsilun,

                                             int64_t sector_num, int nb_sectors)
@@ -715,11 +717,6 @@ static int coroutine_fn iscsi_co_flush(BlockDriverState *bs) 
    IscsiLun *iscsilun = bs->opaque;

    struct IscsiTask iTask;



    if (!iscsilun->force_next_flush) {

        return 0;

    }

    iscsilun->force_next_flush = false;



    iscsi_co_init_iscsitask(iscsilun, &iTask);

retry:

    if (iscsi_synchronizecache10_task(iscsilun->iscsi, iscsilun->lun, 0, 0, 0,
@@ -1019,7 +1016,6 @@ coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, int64_t sector_num, 
    }



    iscsi_co_init_iscsitask(iscsilun, &iTask);

    iTask.force_next_flush = true;

retry:

    if (use_16_for_ws) {

        iTask.task = iscsi_writesame16_task(iscsilun->iscsi, iscsilun->lun, lba,
@@ -1852,6 +1848,8 @@ static BlockDriver bdrv_iscsi = { 
    .bdrv_co_write_zeroes = iscsi_co_write_zeroes,

    .bdrv_co_readv         = iscsi_co_readv,

    .bdrv_co_writev        = iscsi_co_writev,

    .bdrv_co_writev_flags  = iscsi_co_writev_flags,

    .supported_write_flags = BDRV_REQ_FUA,

    .bdrv_co_flush_to_disk = iscsi_co_flush,



#ifdef __linux__