From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:55477) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UKX55-0003L0-9X for qemu-devel@nongnu.org; Tue, 26 Mar 2013 12:50:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UKX53-0001Gt-LL for qemu-devel@nongnu.org; Tue, 26 Mar 2013 12:50:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48242) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UKX53-0001Gh-8M for qemu-devel@nongnu.org; Tue, 26 Mar 2013 12:50:37 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r2QGoaSw012614 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 26 Mar 2013 12:50:36 -0400 From: Kevin Wolf Date: Tue, 26 Mar 2013 17:50:04 +0100 Message-Id: <1364316613-31223-13-git-send-email-kwolf@redhat.com> In-Reply-To: <1364316613-31223-1-git-send-email-kwolf@redhat.com> References: <1364316613-31223-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PATCH v2 12/21] qcow2: Clean up handle_alloc() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com Things can be simplified a bit now. No semantic changes. Signed-off-by: Kevin Wolf --- block/qcow2-cluster.c | 110 ++++++++++++++++++++++++-------------------------- 1 file changed, 53 insertions(+), 57 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 8ed1f7d..1141483 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -886,7 +886,6 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, unsigned int nb_clusters; int ret; - uint64_t alloc_offset; uint64_t alloc_cluster_offset; trace_qcow2_handle_alloc(qemu_coroutine_self(), guest_offset, *host_offset, @@ -928,72 +927,69 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, return 0; } - /* Calculate start and size of allocation */ - alloc_offset = guest_offset; - alloc_cluster_offset = *host_offset; - /* Allocate, if necessary at a given offset in the image file */ - ret = do_alloc_cluster_offset(bs, alloc_offset, &alloc_cluster_offset, + alloc_cluster_offset = *host_offset; + ret = do_alloc_cluster_offset(bs, guest_offset, &alloc_cluster_offset, &nb_clusters); if (ret < 0) { goto fail; } - /* save info needed for meta data update */ - if (nb_clusters > 0) { - /* - * requested_sectors: Number of sectors from the start of the first - * newly allocated cluster to the end of the (possibly shortened - * before) write request. - * - * avail_sectors: Number of sectors from the start of the first - * newly allocated to the end of the last newly allocated cluster. - * - * nb_sectors: The number of sectors from the start of the first - * newly allocated cluster to the end of the aread that the write - * request actually writes to (excluding COW at the end) - */ - int requested_sectors = - (*bytes + offset_into_cluster(s, guest_offset)) - >> BDRV_SECTOR_BITS; - int avail_sectors = nb_clusters - << (s->cluster_bits - BDRV_SECTOR_BITS); - int alloc_n_start = offset_into_cluster(s, guest_offset) - >> BDRV_SECTOR_BITS; - int nb_sectors = MIN(requested_sectors, avail_sectors); - - if (*host_offset == 0) { - *host_offset = alloc_cluster_offset; - } - - *m = g_malloc0(sizeof(**m)); - - **m = (QCowL2Meta) { - .alloc_offset = alloc_cluster_offset, - .offset = alloc_offset & ~(s->cluster_size - 1), - .nb_clusters = nb_clusters, - .nb_available = nb_sectors, - - .cow_start = { - .offset = 0, - .nb_sectors = alloc_n_start, - }, - .cow_end = { - .offset = nb_sectors * BDRV_SECTOR_SIZE, - .nb_sectors = avail_sectors - nb_sectors, - }, - }; - qemu_co_queue_init(&(*m)->dependent_requests); - QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); - - *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE) - - offset_into_cluster(s, guest_offset)); - assert(*bytes != 0); - } else { + /* Can't extend contiguous allocation */ + if (nb_clusters == 0) { *bytes = 0; return 0; } + /* + * Save info needed for meta data update. + * + * requested_sectors: Number of sectors from the start of the first + * newly allocated cluster to the end of the (possibly shortened + * before) write request. + * + * avail_sectors: Number of sectors from the start of the first + * newly allocated to the end of the last newly allocated cluster. + * + * nb_sectors: The number of sectors from the start of the first + * newly allocated cluster to the end of the area that the write + * request actually writes to (excluding COW at the end) + */ + int requested_sectors = + (*bytes + offset_into_cluster(s, guest_offset)) + >> BDRV_SECTOR_BITS; + int avail_sectors = nb_clusters + << (s->cluster_bits - BDRV_SECTOR_BITS); + int alloc_n_start = offset_into_cluster(s, guest_offset) + >> BDRV_SECTOR_BITS; + int nb_sectors = MIN(requested_sectors, avail_sectors); + + *host_offset = alloc_cluster_offset; + + *m = g_malloc0(sizeof(**m)); + + **m = (QCowL2Meta) { + .alloc_offset = *host_offset, + .offset = start_of_cluster(s, guest_offset), + .nb_clusters = nb_clusters, + .nb_available = nb_sectors, + + .cow_start = { + .offset = 0, + .nb_sectors = alloc_n_start, + }, + .cow_end = { + .offset = nb_sectors * BDRV_SECTOR_SIZE, + .nb_sectors = avail_sectors - nb_sectors, + }, + }; + qemu_co_queue_init(&(*m)->dependent_requests); + QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); + + *bytes = MIN(*bytes, (nb_sectors * BDRV_SECTOR_SIZE) + - offset_into_cluster(s, guest_offset)); + assert(*bytes != 0); + return 1; fail: -- 1.8.1.4