From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34319) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YIJmI-0004Go-Kr for qemu-devel@nongnu.org; Mon, 02 Feb 2015 11:23:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YIJmB-0005o3-OX for qemu-devel@nongnu.org; Mon, 02 Feb 2015 11:23:10 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:5229 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YIJmB-0005nA-7X for qemu-devel@nongnu.org; Mon, 02 Feb 2015 11:23:03 -0500 From: "Denis V. Lunev" Date: Mon, 2 Feb 2015 19:23:10 +0300 Message-Id: <1422894190-15477-2-git-send-email-den@openvz.org> In-Reply-To: <1422894190-15477-1-git-send-email-den@openvz.org> References: <1422888514-6495-1-git-send-email-pl@kamp.de> <1422894190-15477-1-git-send-email-den@openvz.org> Subject: [Qemu-devel] [PATCH 2/2] nbd: fix max_discard List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , "Denis V. Lunev" , Peter Lieven , qemu-devel@nongnu.org nbd_co_discard calls nbd_client_session_co_discard which uses uint32_t as the length in bytes of the data to discard due to the following definition: struct nbd_request { uint32_t magic; uint32_t type; uint64_t handle; uint64_t from; uint32_t len; <-- the length of data to be discarded, in bytes } QEMU_PACKED; Thus we should limit bl_max_discard to INT_MAX >> BDRV_SECTOR_BITS to avoid overflow. Signed-off-by: Denis V. Lunev CC: Kevin Wolf CC: Peter Lieven --- block/nbd.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/block/nbd.c b/block/nbd.c index 04cc845..008d52e 100644 --- a/block/nbd.c +++ b/block/nbd.c @@ -301,6 +301,11 @@ static int nbd_co_flush(BlockDriverState *bs) return nbd_client_session_co_flush(&s->client); } +static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) +{ + bs->bl.max_discard = INT_MAX >> BDRV_SECTOR_BITS; +} + static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) { @@ -396,6 +401,7 @@ static BlockDriver bdrv_nbd = { .bdrv_close = nbd_close, .bdrv_co_flush_to_os = nbd_co_flush, .bdrv_co_discard = nbd_co_discard, + .bdrv_refresh_limits = nbd_refresh_limits, .bdrv_getlength = nbd_getlength, .bdrv_detach_aio_context = nbd_detach_aio_context, .bdrv_attach_aio_context = nbd_attach_aio_context, @@ -413,6 +419,7 @@ static BlockDriver bdrv_nbd_tcp = { .bdrv_close = nbd_close, .bdrv_co_flush_to_os = nbd_co_flush, .bdrv_co_discard = nbd_co_discard, + .bdrv_refresh_limits = nbd_refresh_limits, .bdrv_getlength = nbd_getlength, .bdrv_detach_aio_context = nbd_detach_aio_context, .bdrv_attach_aio_context = nbd_attach_aio_context, @@ -430,6 +437,7 @@ static BlockDriver bdrv_nbd_unix = { .bdrv_close = nbd_close, .bdrv_co_flush_to_os = nbd_co_flush, .bdrv_co_discard = nbd_co_discard, + .bdrv_refresh_limits = nbd_refresh_limits, .bdrv_getlength = nbd_getlength, .bdrv_detach_aio_context = nbd_detach_aio_context, .bdrv_attach_aio_context = nbd_attach_aio_context, -- 1.9.1