From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45573) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bBuvt-0005ZP-Es for qemu-devel@nongnu.org; Sat, 11 Jun 2016 22:15:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bBuvs-0006nj-Dw for qemu-devel@nongnu.org; Sat, 11 Jun 2016 22:15:25 -0400 Date: Sun, 12 Jun 2016 10:15:13 +0800 From: Fam Zheng Message-ID: <20160612021513.GB27167@ad.usersys.redhat.com> References: <1465694320-13500-1-git-send-email-eblake@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1465694320-13500-1-git-send-email-eblake@redhat.com> Subject: Re: [Qemu-devel] [PATCH] block: Avoid bogus flags during mirroring List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: qemu-devel@nongnu.org, kwolf@redhat.com, Jeff Cody , qemu-block@nongnu.org, Max Reitz On Sat, 06/11 19:18, Eric Blake wrote: > Commit e253f4b8 converted mirroring from sector-based bdrv_aio_* > to byte-based blk_aio_*, but failed to account for the subtle > difference in signatures (the former takes a semi-redundant length, > the latter takes a flags parameter). Since all of our flags are > currently smaller in size than BDRV_SECTOR_SIZE, it has no ill > effects until we either perform sub-sector mirroring, or we start > asserting that no unexpected flags are set. I found it while > testing new asserts when qemu-iotests 132 started warning about an > unknown flag 0x200000. > > Add an assert to help us catch any other improper flags. > > Signed-off-by: Eric Blake > --- > block/block-backend.c | 2 ++ > block/mirror.c | 6 ++---- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/block/block-backend.c b/block/block-backend.c > index 34500e6..a5dc6e3 100644 > --- a/block/block-backend.c > +++ b/block/block-backend.c > @@ -945,6 +945,8 @@ static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int bytes, > acb->bh = NULL; > acb->has_returned = false; > > + assert(flags <= 0x1f); > + Maybe define BDRV_REQ_FLAGS_MAX in include/block/block.h so it's easier to keep this assertion valid when we introduce more flags in the future? Otherwise the patch looks good. Fam > co = qemu_coroutine_create(co_entry); > qemu_coroutine_enter(co, acb); > > diff --git a/block/mirror.c b/block/mirror.c > index fbbc496..41848b2 100644 > --- a/block/mirror.c > +++ b/block/mirror.c > @@ -157,8 +157,7 @@ static void mirror_read_complete(void *opaque, int ret) > return; > } > blk_aio_pwritev(s->target, op->sector_num * BDRV_SECTOR_SIZE, &op->qiov, > - op->nb_sectors * BDRV_SECTOR_SIZE, > - mirror_write_complete, op); > + 0, mirror_write_complete, op); > } > > static inline void mirror_clip_sectors(MirrorBlockJob *s, > @@ -275,8 +274,7 @@ static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num, > s->sectors_in_flight += nb_sectors; > trace_mirror_one_iteration(s, sector_num, nb_sectors); > > - blk_aio_preadv(source, sector_num * BDRV_SECTOR_SIZE, &op->qiov, > - nb_sectors * BDRV_SECTOR_SIZE, > + blk_aio_preadv(source, sector_num * BDRV_SECTOR_SIZE, &op->qiov, 0, > mirror_read_complete, op); > return ret; > } > -- > 2.5.5 > >