Commit 3dff24f2 authored by Kevin Wolf's avatar Kevin Wolf Committed by Eric Blake
Browse files

nbd: Fix order of bdrv_set_perm and bdrv_invalidate_cache 



The "inactive" state of BDS affects whether the permissions can be
granted, we must call bdrv_invalidate_cache before bdrv_set_perm to
support "-incoming defer" case.

Reported-by: default avatarChristian Ehrhardt <christian.ehrhardt@canonical.com>
Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Message-Id: <20170815130740.31229-3-famz@redhat.com>
Signed-off-by: default avatarEric Blake <eblake@redhat.com>
parent 80adf54e

nbd/server.c

+11 −9
Original line number Diff line number Diff line
@@ -1045,11 +1045,22 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size, 
                          bool writethrough, BlockBackend *on_eject_blk,

                          Error **errp)

{

    AioContext *ctx;

    BlockBackend *blk;

    NBDExport *exp = g_malloc0(sizeof(NBDExport));

    uint64_t perm;

    int ret;



    /*

     * NBD exports are used for non-shared storage migration.  Make sure

     * that BDRV_O_INACTIVE is cleared and the image is ready for write

     * access since the export could be available before migration handover.

     */

    ctx = bdrv_get_aio_context(bs);

    aio_context_acquire(ctx);

    bdrv_invalidate_cache(bs, NULL);

    aio_context_release(ctx);



    /* Don't allow resize while the NBD server is running, otherwise we don't

     * care what happens with the node. */

    perm = BLK_PERM_CONSISTENT_READ;
@@ -1087,15 +1098,6 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size, 
        exp->eject_notifier.notify = nbd_eject_notifier;

        blk_add_remove_bs_notifier(on_eject_blk, &exp->eject_notifier);

    }



    /*

     * NBD exports are used for non-shared storage migration.  Make sure

     * that BDRV_O_INACTIVE is cleared and the image is ready for write

     * access since the export could be available before migration handover.

     */

    aio_context_acquire(exp->ctx);

    blk_invalidate_cache(blk, NULL);

    aio_context_release(exp->ctx);

    return exp;



fail: