From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57808) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dhT6K-0007ba-PZ for qemu-devel@nongnu.org; Tue, 15 Aug 2017 00:05:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dhT6K-00057U-0g for qemu-devel@nongnu.org; Tue, 15 Aug 2017 00:05:08 -0400 From: Fam Zheng Date: Tue, 15 Aug 2017 12:04:52 +0800 Message-Id: <20170815040454.4223-3-famz@redhat.com> In-Reply-To: <20170815040454.4223-1-famz@redhat.com> References: <20170815040454.4223-1-famz@redhat.com> Subject: [Qemu-devel] [PATCH for-2.10 2/4] nbd: Fix order of bdrv_set_perm and bdrv_invalidate_cache List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , qemu-block@nongnu.org, Eric Blake , Kevin Wolf , Max Reitz From: Kevin Wolf 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: Christian Ehrhardt Signed-off-by: Fam Zheng --- nbd/server.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index 82a78bf439..b68b6fb535 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -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: -- 2.13.4