Commit aad0b7a0 authored by Fam Zheng's avatar Fam Zheng Committed by Kevin Wolf
Browse files

block: Inactivate all children 



Currently we only inactivate the top BDS. Actually bdrv_inactivate
should be the opposite of bdrv_invalidate_cache.

Recurse into the whole subtree instead.

Because a node may have multiple parents, and because once
BDRV_O_INACTIVE is set for a node, further writes are not allowed, we
cannot interleave flag settings and .bdrv_inactivate calls (that may
submit write to other nodes in a graph) within a single pass. Therefore
two passes are used here.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent c9e9e9c6

block.c

+36 −11
Original line number Diff line number Diff line
@@ -3255,38 +3255,63 @@ void bdrv_invalidate_cache_all(Error **errp) 
    }

}



static int bdrv_inactivate(BlockDriverState *bs)

static int bdrv_inactivate_recurse(BlockDriverState *bs,

                                   bool setting_flag)

{

    BdrvChild *child;

    int ret;



    if (bs->drv->bdrv_inactivate) {

    if (!setting_flag && bs->drv->bdrv_inactivate) {

        ret = bs->drv->bdrv_inactivate(bs);

        if (ret < 0) {

            return ret;

        }

    }



    QLIST_FOREACH(child, &bs->children, next) {

        ret = bdrv_inactivate_recurse(child->bs, setting_flag);

        if (ret < 0) {

            return ret;

        }

    }



    if (setting_flag) {

        bs->open_flags |= BDRV_O_INACTIVE;

    }

    return 0;

}



int bdrv_inactivate_all(void)

{

    BlockDriverState *bs = NULL;

    int ret;

    int ret = 0;

    int pass;



    while ((bs = bdrv_next(bs)) != NULL) {

        AioContext *aio_context = bdrv_get_aio_context(bs);

        aio_context_acquire(bdrv_get_aio_context(bs));

    }



        aio_context_acquire(aio_context);

        ret = bdrv_inactivate(bs);

        aio_context_release(aio_context);

    /* We do two passes of inactivation. The first pass calls to drivers'

     * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;

     * the second pass sets the BDRV_O_INACTIVE flag so that no further write

     * is allowed. */

    for (pass = 0; pass < 2; pass++) {

        bs = NULL;

        while ((bs = bdrv_next(bs)) != NULL) {

            ret = bdrv_inactivate_recurse(bs, pass);

            if (ret < 0) {

            return ret;

                goto out;

            }

        }

    }



    return 0;

out:

    bs = NULL;

    while ((bs = bdrv_next(bs)) != NULL) {

        aio_context_release(bdrv_get_aio_context(bs));

    }



    return ret;

}



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