From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34196) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d0I2U-0005Uf-M6 for qemu-devel@nongnu.org; Mon, 17 Apr 2017 21:34:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d0I2T-0003oe-J9 for qemu-devel@nongnu.org; Mon, 17 Apr 2017 21:34:42 -0400 From: Eric Blake Date: Mon, 17 Apr 2017 20:33:40 -0500 Message-Id: <20170418013356.3578-16-eblake@redhat.com> In-Reply-To: <20170418013356.3578-1-eblake@redhat.com> References: <20170418013356.3578-1-eblake@redhat.com> Subject: [Qemu-devel] [PATCH 15/31] iscsi: Switch cluster_sectors to byte-based List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, kwolf@nongnu.org, jsnow@redhat.com, Ronnie Sahlberg , Paolo Bonzini , Peter Lieven , Kevin Wolf , Max Reitz 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 --- block/iscsi.c | 56 +++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 35 insertions(+), 21 deletions(-) diff --git a/block/iscsi.c b/block/iscsi.c index 5daa201..9648a45 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -79,7 +79,7 @@ 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; @@ -460,9 +460,10 @@ 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) { @@ -470,7 +471,7 @@ 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; @@ -491,17 +492,19 @@ 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); @@ -565,9 +568,12 @@ 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, @@ -577,9 +583,12 @@ 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 @@ -814,16 +823,21 @@ 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; } @@ -1944,8 +1958,8 @@ 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); } @@ -2143,7 +2157,7 @@ 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; } -- 2.9.3