From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41844) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dPlez-0003Zk-Cr for qemu-devel@nongnu.org; Tue, 27 Jun 2017 04:15:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dPley-0002pE-9D for qemu-devel@nongnu.org; Tue, 27 Jun 2017 04:15:45 -0400 Date: Tue, 27 Jun 2017 16:15:33 +0800 From: Fam Zheng Message-ID: <20170627081533.GE14166@lemon.lan> References: <1496649172-26982-1-git-send-email-ashijeetacharya@gmail.com> <1496649172-26982-9-git-send-email-ashijeetacharya@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1496649172-26982-9-git-send-email-ashijeetacharya@gmail.com> Subject: Re: [Qemu-devel] [PATCH v6 8/8] vmdk: Make vmdk_get_cluster_offset() return cluster offset only List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ashijeet Acharya Cc: kwolf@redhat.com, jsnow@redhat.com, mreitz@redhat.com, stefanha@gmail.com, qemu-devel@nongnu.org, qemu-block@nongnu.org On Mon, 06/05 13:22, Ashijeet Acharya wrote: > vmdk_alloc_clusters() introduced earlier now handles the task of > allocating clusters and performing COW when needed. Thus we can change > vmdk_get_cluster_offset() to stick to the sole purpose of returning > cluster offset using sector number. Update the changes at all call > sites. > > Signed-off-by: Ashijeet Acharya > --- > block/vmdk.c | 56 ++++++++++++-------------------------------------------- > 1 file changed, 12 insertions(+), 44 deletions(-) > > diff --git a/block/vmdk.c b/block/vmdk.c > index 9fa2414..accf1c3 100644 > --- a/block/vmdk.c > +++ b/block/vmdk.c > @@ -1485,25 +1485,16 @@ static int vmdk_alloc_clusters(BlockDriverState *bs, > * For flat extents, the start offset as parsed from the description file is > * returned. > * > - * For sparse extents, look up in L1, L2 table. If allocate is true, return an > - * offset for a new cluster and update L2 cache. If there is a backing file, > - * COW is done before returning; otherwise, zeroes are written to the allocated > - * cluster. Both COW and zero writing skips the sector range > - * [@skip_start_sector, @skip_end_sector) passed in by caller, because caller > - * has new data to write there. > + * For sparse extents, look up the L1, L2 table. > * > * Returns: VMDK_OK if cluster exists and mapped in the image. > - * VMDK_UNALLOC if cluster is not mapped and @allocate is false. > - * VMDK_ERROR if failed. > + * VMDK_UNALLOC if cluster is not mapped. > + * VMDK_ERROR if failed > */ > static int vmdk_get_cluster_offset(BlockDriverState *bs, > VmdkExtent *extent, > - VmdkMetaData *m_data, > uint64_t offset, > - bool allocate, > - uint64_t *cluster_offset, > - uint64_t skip_start_bytes, > - uint64_t skip_end_bytes) > + uint64_t *cluster_offset) > { > int l1_index, l2_offset, l2_index; > uint32_t *l2_table; > @@ -1528,31 +1519,9 @@ static int vmdk_get_cluster_offset(BlockDriverState *bs, > } > > if (!cluster_sector || zeroed) { > - if (!allocate) { > - return zeroed ? VMDK_ZEROED : VMDK_UNALLOC; > - } > - > - cluster_sector = extent->next_cluster_sector; > - extent->next_cluster_sector += extent->cluster_sectors; > - > - /* First of all we write grain itself, to avoid race condition > - * that may to corrupt the image. > - * This problem may occur because of insufficient space on host disk > - * or inappropriate VM shutdown. > - */ > - ret = vmdk_perform_cow(bs, extent, cluster_sector * BDRV_SECTOR_SIZE, > - offset, skip_start_bytes, skip_end_bytes); > - if (ret) { > - return ret; > - } > - if (m_data) { > - m_data->valid = 1; > - m_data->l1_index = l1_index; > - m_data->l2_index = l2_index; > - m_data->l2_offset = l2_offset; > - m_data->l2_cache_entry = &l2_table[l2_index]; > - } > + return zeroed ? VMDK_ZEROED : VMDK_UNALLOC; > } > + > *cluster_offset = cluster_sector << BDRV_SECTOR_BITS; > return VMDK_OK; > } > @@ -1595,9 +1564,7 @@ static int64_t coroutine_fn vmdk_co_get_block_status(BlockDriverState *bs, > return 0; > } > qemu_co_mutex_lock(&s->lock); > - ret = vmdk_get_cluster_offset(bs, extent, NULL, > - sector_num * 512, false, &offset, > - 0, 0); > + ret = vmdk_get_cluster_offset(bs, extent, sector_num * 512, &offset); > qemu_co_mutex_unlock(&s->lock); > > index_in_cluster = vmdk_find_index_in_cluster(extent, sector_num); > @@ -1788,13 +1755,14 @@ vmdk_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, > ret = -EIO; > goto fail; > } > - ret = vmdk_get_cluster_offset(bs, extent, NULL, > - offset, false, &cluster_offset, 0, 0); > + > offset_in_cluster = vmdk_find_offset_in_cluster(extent, offset); > > n_bytes = MIN(bytes, extent->cluster_sectors * BDRV_SECTOR_SIZE > - offset_in_cluster); > > + ret = vmdk_get_cluster_offset(bs, extent, offset, &cluster_offset); > + > if (ret != VMDK_OK) { > /* if not allocated, try to read from parent image, if exist */ > if (bs->backing && ret != VMDK_ZEROED) { > @@ -2541,9 +2509,9 @@ static int vmdk_check(BlockDriverState *bs, BdrvCheckResult *result, > sector_num); > break; > } > - ret = vmdk_get_cluster_offset(bs, extent, NULL, > + ret = vmdk_get_cluster_offset(bs, extent, > sector_num << BDRV_SECTOR_BITS, > - false, &cluster_offset, 0, 0); > + &cluster_offset); > if (ret == VMDK_ERROR) { > fprintf(stderr, > "ERROR: could not get cluster_offset for sector %" > -- > 2.6.2 > Reviewed-by: Fam Zheng