From patchwork Sat Mar 25 11:18:18 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ashijeet Acharya X-Patchwork-Id: 9644519 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4C9EC60327 for ; Sat, 25 Mar 2017 11:20:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4AACD265B9 for ; Sat, 25 Mar 2017 11:20:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3B6DE26907; Sat, 25 Mar 2017 11:20:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_WEB, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9015B265B9 for ; Sat, 25 Mar 2017 11:20:01 +0000 (UTC) Received: from localhost ([::1]:36731 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1crjjk-0001Qn-Fx for patchwork-qemu-devel@patchwork.kernel.org; Sat, 25 Mar 2017 07:20:00 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35206) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1crjiJ-0001Hh-Cu for qemu-devel@nongnu.org; Sat, 25 Mar 2017 07:18:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1crjiI-0000r3-0a for qemu-devel@nongnu.org; Sat, 25 Mar 2017 07:18:31 -0400 Received: from mail-pg0-x241.google.com ([2607:f8b0:400e:c05::241]:34564) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1crjiH-0000qw-OM; Sat, 25 Mar 2017 07:18:29 -0400 Received: by mail-pg0-x241.google.com with SMTP id w20so2563701pgc.1; Sat, 25 Mar 2017 04:18:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=1aemnwh64PNofCEXHxmUSKcurDJt++aH6t2t8xwe1BA=; b=o8zzGubU8wJgwSrebKW7zoBNg+hO6/QzNQVcK1Ww+omj7kVBVp8lV0KIfS6PqBCTGq nRcnpH//EfOFXJwQdCdSTf5cdQsT7sgYnxFSHri5cds4EzCHG4cj0XbKB2/ba/BJNZr/ VZ8+1ucRX17+uC+9r/3DtKy7I4VAlkZkVJmZPGFeXr0hNnoDajdrnhTNdGzEzmH8mLxr IPP6WX2+sFozXzhvhTt4vN48BtdAOiy9VWT6NjUg5mDvQreqMpu3ZChKmvI3X39mNFTg DMyeLod/HIAzUOEF46NsJPF6du57HHQnBKhLuux+3V4+MqMjFA5VeJeGgdV3eYIRe0Gk l1cg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=1aemnwh64PNofCEXHxmUSKcurDJt++aH6t2t8xwe1BA=; b=RNE6VV+Tl1Tc7/G7qYUvyedK3wp74Ds6ggfkBl/ZF6sisCq+dI+GO40fGGspB0zTxY 9SiX4hLSFhKNAO8Hl5uOJWRg55WTFS4kB4WOyHq1tzUPfBTN1/2/wzqDJRdMUdcet4Hs YtvAcOmbuPcJ4k/lvVkKpiYdLQdyOGRFB32N7RjzJAef/woCt4ReZn0pehFzUAlLJsDK L8hCjAUnh/cjvLsYx3Km/e8/R1wLe0g1eBuRzT1mdlE0d1ZUptNK/z1WREIVg9tCFyn0 wcf7QeavPFCEfrGqZEHqPAFnJBPdX52gkQ6Cgj/2NPi8Pb55xnSia1SOTcfhE/TkGZw9 GiwQ== X-Gm-Message-State: AFeK/H1RhOh+1S1CNvC8FPHLV3ptm8/d//1D9KaYaOKhy3b3CkaLWSbaC9kmPhATm+qOyw== X-Received: by 10.98.108.196 with SMTP id h187mr14750087pfc.233.1490440708886; Sat, 25 Mar 2017 04:18:28 -0700 (PDT) Received: from linux.local ([27.251.197.196]) by smtp.gmail.com with ESMTPSA id p189sm9952620pfb.128.2017.03.25.04.18.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sat, 25 Mar 2017 04:18:28 -0700 (PDT) From: Ashijeet Acharya To: famz@redhat.com Date: Sat, 25 Mar 2017 16:48:18 +0530 Message-Id: <1490440701-12037-5-git-send-email-ashijeetacharya@gmail.com> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1490440701-12037-1-git-send-email-ashijeetacharya@gmail.com> References: <1490440701-12037-1-git-send-email-ashijeetacharya@gmail.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2607:f8b0:400e:c05::241 Subject: [Qemu-devel] [PATCH v2 4/7] vmdk: New functions to allocate multiple clusters and cluster offset X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-block@nongnu.org, stefanha@gmail.com, qemu-devel@nongnu.org, mreitz@redhat.com, Ashijeet Acharya , jsnow@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Introduce two new helper functions handle_alloc() and vmdk_alloc_cluster_offset(). handle_alloc() helps to allocate multiple clusters at once starting from a given offset on disk and performs COW if necessary for first and last allocated clusters. vmdk_alloc_cluster_offset() helps to return the offset of the first of the many newly allocated clusters. Also, provide proper documentation for both. Signed-off-by: Ashijeet Acharya --- block/vmdk.c | 206 +++++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 187 insertions(+), 19 deletions(-) diff --git a/block/vmdk.c b/block/vmdk.c index a42322e..5a95929 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -136,6 +136,7 @@ typedef struct VmdkMetaData { unsigned int l2_offset; int valid; uint32_t *l2_cache_entry; + uint32_t nb_clusters; } VmdkMetaData; typedef struct VmdkGrainMarker { @@ -1036,6 +1037,34 @@ static void vmdk_refresh_limits(BlockDriverState *bs, Error **errp) } } +static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data, + uint32_t offset) +{ + offset = cpu_to_le32(offset); + /* update L2 table */ + if (bdrv_pwrite_sync(extent->file, + ((int64_t)m_data->l2_offset * 512) + + (m_data->l2_index * sizeof(offset)), + &offset, sizeof(offset)) < 0) { + return VMDK_ERROR; + } + /* update backup L2 table */ + if (extent->l1_backup_table_offset != 0) { + m_data->l2_offset = extent->l1_backup_table[m_data->l1_index]; + if (bdrv_pwrite_sync(extent->file, + ((int64_t)m_data->l2_offset * 512) + + (m_data->l2_index * sizeof(offset)), + &offset, sizeof(offset)) < 0) { + return VMDK_ERROR; + } + } + if (m_data->l2_cache_entry) { + *m_data->l2_cache_entry = offset; + } + + return VMDK_OK; +} + /* * vmdk_L2load * @@ -1222,29 +1251,168 @@ exit: return ret; } -static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data, - uint32_t offset) +/* + * handle_alloc + * + * Allocates new clusters for an area that either is yet unallocated or needs a + * copy on write. If *cluster_offset is non_zero, clusters are only allocated if + * the new allocation can match the specified host offset. + * + * Returns: + * VMDK_OK: if new clusters were allocated, *bytes may be decreased if + * the new allocation doesn't cover all of the requested area. + * *cluster_offset is updated to contain the offset of the + * first newly allocated cluster. + * + * VMDK_UNALLOC: if no clusters could be allocated. *cluster_offset is left + * unchanged. + * + * VMDK_ERROR: in error cases + */ +static int handle_alloc(BlockDriverState *bs, VmdkExtent *extent, + uint64_t offset, uint64_t *cluster_offset, + int64_t *bytes, VmdkMetaData *m_data, + bool allocate, uint32_t *total_alloc_clusters) { - offset = cpu_to_le32(offset); - /* update L2 table */ - if (bdrv_pwrite_sync(extent->file, - ((int64_t)m_data->l2_offset * 512) - + (m_data->l2_index * sizeof(offset)), - &offset, sizeof(offset)) < 0) { - return VMDK_ERROR; + int l1_index, l2_offset, l2_index; + uint32_t *l2_table; + uint32_t cluster_sector; + uint32_t nb_clusters; + bool zeroed = false; + uint64_t skip_start_bytes, skip_end_bytes; + int ret; + + ret = get_cluster_table(extent, offset, &l1_index, &l2_offset, + &l2_index, &l2_table); + if (ret < 0) { + return ret; } - /* update backup L2 table */ - if (extent->l1_backup_table_offset != 0) { - m_data->l2_offset = extent->l1_backup_table[m_data->l1_index]; - if (bdrv_pwrite_sync(extent->file, - ((int64_t)m_data->l2_offset * 512) - + (m_data->l2_index * sizeof(offset)), - &offset, sizeof(offset)) < 0) { - return VMDK_ERROR; + + cluster_sector = le32_to_cpu(l2_table[l2_index]); + + skip_start_bytes = vmdk_find_offset_in_cluster(extent, offset); + /* Calculate the number of clusters to look for. Here it will return one + * cluster less than the actual value calculated as we may need to perfrom + * COW for the last one. */ + nb_clusters = size_to_clusters(extent, skip_start_bytes + *bytes); + + nb_clusters = MIN(nb_clusters, extent->l2_size - l2_index); + assert(nb_clusters <= INT_MAX); + + /* update bytes according to final nb_clusters value */ + if (nb_clusters != 0) { + *bytes = ((nb_clusters * extent->cluster_sectors) << 9) + - skip_start_bytes; + } else { + nb_clusters = 1; + } + *total_alloc_clusters += nb_clusters; + skip_end_bytes = skip_start_bytes + MIN(*bytes, + extent->cluster_sectors * BDRV_SECTOR_SIZE + - skip_start_bytes); + + if (extent->has_zero_grain && cluster_sector == VMDK_GTE_ZEROED) { + zeroed = true; + } + + 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 + * nb_clusters; + + ret = vmdk_perform_cow(bs, extent, cluster_sector * BDRV_SECTOR_SIZE, + offset, skip_start_bytes, + skip_end_bytes); + if (ret < 0) { + 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]; + m_data->nb_clusters = nb_clusters; } } - if (m_data->l2_cache_entry) { - *m_data->l2_cache_entry = offset; + *cluster_offset = cluster_sector << BDRV_SECTOR_BITS; + return VMDK_OK; +} + +/* + * vmdk_alloc_cluster_offset + * + * For a given offset on the virtual disk, find the cluster offset in vmdk + * file. If the offset is not found, allocate a new cluster. + * + * If the cluster is newly allocated, m_data->nb_clusters is set to the number + * of contiguous clusters that have been allocated. In this case, the other + * fields of m_data are valid and contain information about the first allocated + * cluster. + * + * Returns: + * + * VMDK_OK: on success and @cluster_offset was set + * + * VMDK_UNALLOC: if no clusters were allocated and @cluster_offset is + * set to zero + * + * VMDK_ERROR: in error cases + */ +static int vmdk_alloc_cluster_offset(BlockDriverState *bs, + VmdkExtent *extent, + VmdkMetaData *m_data, uint64_t offset, + bool allocate, uint64_t *cluster_offset, + int64_t bytes, + uint32_t *total_alloc_clusters) +{ + uint64_t start, remaining; + uint64_t new_cluster_offset; + int64_t n_bytes; + int ret; + + if (extent->flat) { + *cluster_offset = extent->flat_start_offset; + return VMDK_OK; + } + + start = offset; + remaining = bytes; + new_cluster_offset = 0; + *cluster_offset = 0; + n_bytes = 0; + if (m_data) { + m_data->valid = 0; + } + + /* due to L2 table margins all bytes may not get allocated at once */ + while (true) { + + if (!*cluster_offset) { + *cluster_offset = new_cluster_offset; + } + + start += n_bytes; + remaining -= n_bytes; + new_cluster_offset += n_bytes; + + if (remaining == 0) { + break; + } + + n_bytes = remaining; + + ret = handle_alloc(bs, extent, start, &new_cluster_offset, &n_bytes, + m_data, allocate, total_alloc_clusters); + + if (ret < 0) { + return ret; + + } } return VMDK_OK;