From nobody Mon Feb 9 02:27:33 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; dkim=fail spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1490440834360691.3215735079965; Sat, 25 Mar 2017 04:20:34 -0700 (PDT) Received: from localhost ([::1]:36740 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1crjkH-0002bJ-48 for importer@patchew.org; Sat, 25 Mar 2017 07:20:33 -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) 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) 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) 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZohoMail: RDKM_2 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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; =20 typedef struct VmdkGrainMarker { @@ -1036,6 +1037,34 @@ static void vmdk_refresh_limits(BlockDriverState *bs= , Error **errp) } } =20 +static int vmdk_L2update(VmdkExtent *extent, VmdkMetaData *m_data, + uint32_t offset) +{ + offset =3D 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 !=3D 0) { + m_data->l2_offset =3D 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 =3D offset; + } + + return VMDK_OK; +} + /* * vmdk_L2load * @@ -1222,29 +1251,168 @@ exit: return ret; } =20 -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 ne= eds a + * copy on write. If *cluster_offset is non_zero, clusters are only alloca= ted if + * the new allocation can match the specified host offset. + * + * Returns: + * VMDK_OK: if new clusters were allocated, *bytes may be decrease= d 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 =3D 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 =3D false; + uint64_t skip_start_bytes, skip_end_bytes; + int ret; + + ret =3D 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 !=3D 0) { - m_data->l2_offset =3D 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 =3D le32_to_cpu(l2_table[l2_index]); + + skip_start_bytes =3D vmdk_find_offset_in_cluster(extent, offset); + /* Calculate the number of clusters to look for. Here it will return o= ne + * cluster less than the actual value calculated as we may need to per= from + * COW for the last one. */ + nb_clusters =3D size_to_clusters(extent, skip_start_bytes + *bytes); + + nb_clusters =3D MIN(nb_clusters, extent->l2_size - l2_index); + assert(nb_clusters <=3D INT_MAX); + + /* update bytes according to final nb_clusters value */ + if (nb_clusters !=3D 0) { + *bytes =3D ((nb_clusters * extent->cluster_sectors) << 9) + - skip_start_bytes; + } else { + nb_clusters =3D 1; + } + *total_alloc_clusters +=3D nb_clusters; + skip_end_bytes =3D skip_start_bytes + MIN(*bytes, + extent->cluster_sectors * BDRV_SECTOR_SIZE + - skip_start_bytes); + + if (extent->has_zero_grain && cluster_sector =3D=3D VMDK_GTE_ZEROED) { + zeroed =3D true; + } + + if (!cluster_sector || zeroed) { + if (!allocate) { + return zeroed ? VMDK_ZEROED : VMDK_UNALLOC; + } + + cluster_sector =3D extent->next_cluster_sector; + extent->next_cluster_sector +=3D extent->cluster_sectors + * nb_clusters; + + ret =3D 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 =3D 1; + m_data->l1_index =3D l1_index; + m_data->l2_index =3D l2_index; + m_data->l2_offset =3D l2_offset; + m_data->l2_cache_entry =3D &l2_table[l2_index]; + m_data->nb_clusters =3D nb_clusters; } } - if (m_data->l2_cache_entry) { - *m_data->l2_cache_entry =3D offset; + *cluster_offset =3D 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 nu= mber + * of contiguous clusters that have been allocated. In this case, the other + * fields of m_data are valid and contain information about the first allo= cated + * 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_offs= et, + 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 =3D extent->flat_start_offset; + return VMDK_OK; + } + + start =3D offset; + remaining =3D bytes; + new_cluster_offset =3D 0; + *cluster_offset =3D 0; + n_bytes =3D 0; + if (m_data) { + m_data->valid =3D 0; + } + + /* due to L2 table margins all bytes may not get allocated at once */ + while (true) { + + if (!*cluster_offset) { + *cluster_offset =3D new_cluster_offset; + } + + start +=3D n_bytes; + remaining -=3D n_bytes; + new_cluster_offset +=3D n_bytes; + + if (remaining =3D=3D 0) { + break; + } + + n_bytes =3D remaining; + + ret =3D handle_alloc(bs, extent, start, &new_cluster_offset, &n_by= tes, + m_data, allocate, total_alloc_clusters); + + if (ret < 0) { + return ret; + + } } =20 return VMDK_OK; --=20 2.6.2