From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53293) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e4kXM-0001Fk-E0 for qemu-devel@nongnu.org; Wed, 18 Oct 2017 05:21:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e4kXL-0003yi-6K for qemu-devel@nongnu.org; Wed, 18 Oct 2017 05:21:16 -0400 References: <20171012185916.22776-1-eblake@redhat.com> <20171012185916.22776-6-eblake@redhat.com> From: Paolo Bonzini Message-ID: Date: Wed, 18 Oct 2017 11:20:35 +0200 MIME-Version: 1.0 In-Reply-To: <20171012185916.22776-6-eblake@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 05/20] iscsi: Switch cluster_sectors to byte-based List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, kwolf@redhat.com, famz@redhat.com, jsnow@redhat.com, Ronnie Sahlberg , Peter Lieven , Max Reitz On 12/10/2017 20:59, Eric Blake wrote: > We are gradually converting to byte-based interfaces, as they are > easier to reason about than sector-based. Convert all uses of > the cluster size in sectors, along with adding assertions that we > are not dividing by zero. > > Signed-off-by: Eric Blake > > --- > v2: no change > --- > block/iscsi.c | 56 +++++++++++++++++++++++++++++++++++--------------------- > 1 file changed, 35 insertions(+), 21 deletions(-) > > diff --git a/block/iscsi.c b/block/iscsi.c > index 4683f3b244..8f903d8370 100644 > --- a/block/iscsi.c > +++ b/block/iscsi.c > @@ -84,7 +84,7 @@ typedef struct IscsiLun { > unsigned long *allocmap; > unsigned long *allocmap_valid; > long allocmap_size; > - int cluster_sectors; > + int cluster_size; > bool use_16_for_rw; > bool write_protected; > bool lbpme; > @@ -427,9 +427,10 @@ static int iscsi_allocmap_init(IscsiLun *iscsilun, int open_flags) > { > iscsi_allocmap_free(iscsilun); > > + assert(iscsilun->cluster_size); > iscsilun->allocmap_size = > - DIV_ROUND_UP(sector_lun2qemu(iscsilun->num_blocks, iscsilun), > - iscsilun->cluster_sectors); > + DIV_ROUND_UP(iscsilun->num_blocks * iscsilun->block_size, > + iscsilun->cluster_size); > > iscsilun->allocmap = bitmap_try_new(iscsilun->allocmap_size); > if (!iscsilun->allocmap) { > @@ -437,7 +438,7 @@ static int iscsi_allocmap_init(IscsiLun *iscsilun, int open_flags) > } > > if (open_flags & BDRV_O_NOCACHE) { > - /* in case that cache.direct = on all allocmap entries are > + /* when cache.direct = on all allocmap entries are > * treated as invalid to force a relookup of the block > * status on every read request */ > return 0; > @@ -458,17 +459,19 @@ iscsi_allocmap_update(IscsiLun *iscsilun, int64_t sector_num, > int nb_sectors, bool allocated, bool valid) > { > int64_t cl_num_expanded, nb_cls_expanded, cl_num_shrunk, nb_cls_shrunk; > + int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS; > > if (iscsilun->allocmap == NULL) { > return; > } > /* expand to entirely contain all affected clusters */ > - cl_num_expanded = sector_num / iscsilun->cluster_sectors; > + assert(cluster_sectors); > + cl_num_expanded = sector_num / cluster_sectors; > nb_cls_expanded = DIV_ROUND_UP(sector_num + nb_sectors, > - iscsilun->cluster_sectors) - cl_num_expanded; > + cluster_sectors) - cl_num_expanded; > /* shrink to touch only completely contained clusters */ > - cl_num_shrunk = DIV_ROUND_UP(sector_num, iscsilun->cluster_sectors); > - nb_cls_shrunk = (sector_num + nb_sectors) / iscsilun->cluster_sectors > + cl_num_shrunk = DIV_ROUND_UP(sector_num, cluster_sectors); > + nb_cls_shrunk = (sector_num + nb_sectors) / cluster_sectors > - cl_num_shrunk; > if (allocated) { > bitmap_set(iscsilun->allocmap, cl_num_expanded, nb_cls_expanded); > @@ -532,9 +535,12 @@ iscsi_allocmap_is_allocated(IscsiLun *iscsilun, int64_t sector_num, > if (iscsilun->allocmap == NULL) { > return true; > } > - size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors); > + assert(iscsilun->cluster_size); > + size = DIV_ROUND_UP(sector_num + nb_sectors, > + iscsilun->cluster_size >> BDRV_SECTOR_BITS); > return !(find_next_bit(iscsilun->allocmap, size, > - sector_num / iscsilun->cluster_sectors) == size); > + sector_num * BDRV_SECTOR_SIZE / > + iscsilun->cluster_size) == size); > } > > static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun, > @@ -544,9 +550,12 @@ static inline bool iscsi_allocmap_is_valid(IscsiLun *iscsilun, > if (iscsilun->allocmap_valid == NULL) { > return false; > } > - size = DIV_ROUND_UP(sector_num + nb_sectors, iscsilun->cluster_sectors); > + assert(iscsilun->cluster_size); > + size = DIV_ROUND_UP(sector_num + nb_sectors, > + iscsilun->cluster_size >> BDRV_SECTOR_BITS); > return (find_next_zero_bit(iscsilun->allocmap_valid, size, > - sector_num / iscsilun->cluster_sectors) == size); > + sector_num * BDRV_SECTOR_SIZE / > + iscsilun->cluster_size) == size); > } > > static int coroutine_fn > @@ -781,16 +790,21 @@ static int coroutine_fn iscsi_co_readv(BlockDriverState *bs, > BlockDriverState *file; > /* check the block status from the beginning of the cluster > * containing the start sector */ > - int64_t ret = iscsi_co_get_block_status(bs, > - sector_num - sector_num % iscsilun->cluster_sectors, > - BDRV_REQUEST_MAX_SECTORS, &pnum, &file); > + int cluster_sectors = iscsilun->cluster_size >> BDRV_SECTOR_BITS; > + int head; > + int64_t ret; > + > + assert(cluster_sectors); > + head = sector_num % cluster_sectors; > + ret = iscsi_co_get_block_status(bs, sector_num - head, > + BDRV_REQUEST_MAX_SECTORS, &pnum, > + &file); > if (ret < 0) { > return ret; > } > /* if the whole request falls into an unallocated area we can avoid > - * to read and directly return zeroes instead */ > - if (ret & BDRV_BLOCK_ZERO && > - pnum >= nb_sectors + sector_num % iscsilun->cluster_sectors) { > + * reading and directly return zeroes instead */ > + if (ret & BDRV_BLOCK_ZERO && pnum >= nb_sectors + head) { > qemu_iovec_memset(iov, 0, 0x00, iov->size); > return 0; > } > @@ -1930,8 +1944,8 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags, > * reasonable size */ > if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 && > iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) { > - iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran * > - iscsilun->block_size) >> BDRV_SECTOR_BITS; > + iscsilun->cluster_size = iscsilun->bl.opt_unmap_gran * > + iscsilun->block_size; > if (iscsilun->lbprz) { > ret = iscsi_allocmap_init(iscsilun, bs->open_flags); > } > @@ -2137,7 +2151,7 @@ static int iscsi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) > IscsiLun *iscsilun = bs->opaque; > bdi->unallocated_blocks_are_zero = iscsilun->lbprz; > bdi->can_write_zeroes_with_unmap = iscsilun->lbprz && iscsilun->lbp.lbpws; > - bdi->cluster_size = iscsilun->cluster_sectors * BDRV_SECTOR_SIZE; > + bdi->cluster_size = iscsilun->cluster_size; > return 0; > } > Acked-by: Paolo Bonzini