Commit 4085f5c7 authored by John Snow's avatar John Snow Committed by Kevin Wolf
Browse files

block: reintroduce bdrv_flush_all 



Commit fe1a9cbc moved the flush_all routine from the bdrv layer to the
block-backend layer. In doing so, however, the semantics of the routine
changed slightly such that flush_all now used blk_flush instead of
bdrv_flush.

blk_flush can fail if the attached device model reports that it is not
"available," (i.e. the tray is open.) This changed the semantics of
flush_all such that it can now fail for e.g. open CDROM drives.

Reintroduce bdrv_flush_all to regain the old semantics without having to
alter the behavior of blk_flush or blk_flush_all, which are already
'doing the right thing.'

Signed-off-by: default avatarJohn Snow <jsnow@redhat.com>
Reviewed-by: default avatarKevin Wolf <kwolf@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
Acked-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent c640f284

block/io.c

+25 −0
Original line number Diff line number Diff line
@@ -1619,6 +1619,31 @@ int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset, 
                           BDRV_REQ_ZERO_WRITE | flags);

}



/*

 * Flush ALL BDSes regardless of if they are reachable via a BlkBackend or not.

 */

int bdrv_flush_all(void)

{

    BdrvNextIterator it;

    BlockDriverState *bs = NULL;

    int result = 0;



    for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {

        AioContext *aio_context = bdrv_get_aio_context(bs);

        int ret;



        aio_context_acquire(aio_context);

        ret = bdrv_flush(bs);

        if (ret < 0 && !result) {

            result = ret;

        }

        aio_context_release(aio_context);

    }



    return result;

}





typedef struct BdrvCoGetBlockStatusData {

    BlockDriverState *bs;

    BlockDriverState *base;

include/block/block.h

+1 −0
Original line number Diff line number Diff line
@@ -333,6 +333,7 @@ int bdrv_inactivate_all(void); 
/* Ensure contents are flushed to disk.  */

int bdrv_flush(BlockDriverState *bs);

int coroutine_fn bdrv_co_flush(BlockDriverState *bs);

int bdrv_flush_all(void);

void bdrv_close_all(void);

void bdrv_drain(BlockDriverState *bs);

void coroutine_fn bdrv_co_drain(BlockDriverState *bs);