From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 8B5D41FF39E for ; Mon, 27 May 2024 16:34:01 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 9F14A5540; Mon, 27 May 2024 16:34:08 +0200 (CEST) From: Christian Ebner To: pbs-devel@lists.proxmox.com Date: Mon, 27 May 2024 16:33:11 +0200 Message-Id: <20240527143323.456002-58-c.ebner@proxmox.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240527143323.456002-1-c.ebner@proxmox.com> References: <20240527143323.456002-1-c.ebner@proxmox.com> MIME-Version: 1.0 X-SPAM-LEVEL: Spam detection results: 0 AWL -0.371 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_ASCII_DIVIDERS 0.8 Email that uses ascii formatting dividers and possible spam tricks KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record T_SCC_BODY_TEXT_LINE -0.01 - Subject: [pbs-devel] [PATCH v7 proxmox-backup 57/69] docs: file formats: describe split pxar archive file layout X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Proxmox Backup Server development discussion Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pbs-devel-bounces@lists.proxmox.com Sender: "pbs-devel" Describes the pxar metadata archive and the corresponding pxar payload file-format layout. Signed-off-by: Christian Ebner --- changes since version 6: - no changes docs/file-formats.rst | 46 ++++++++++++++++++++++++++++++++ docs/meta-format-overview.dot | 50 +++++++++++++++++++++++++++++++++++ 2 files changed, 96 insertions(+) create mode 100644 docs/meta-format-overview.dot diff --git a/docs/file-formats.rst b/docs/file-formats.rst index 43ecfefce..77d55b5ef 100644 --- a/docs/file-formats.rst +++ b/docs/file-formats.rst @@ -8,7 +8,53 @@ Proxmox File Archive Format (``.pxar``) .. graphviz:: pxar-format-overview.dot +.. _pxar-meta-format: +Proxmox File Archive Format - Meta (``.mpxar``) +----------------------------------------------- + +Pxar metadata archive with same structure as a regular pxar archive, with the +exception of regular file payloads not being contained within the archive +itself, but rather being stored as payload references to the corresponding pxar +payload (``.ppxar``) file. + +Can be used to lookup all the archive entries and metadata without the size +overhead introduced by the file payloads. + +.. graphviz:: meta-format-overview.dot + +.. _ppxar-format: + +Proxmox File Archive Format - Payload (``.ppxar``) +-------------------------------------------------- + +Pxar payload file storing regular file payloads to be referenced and accessed by +the corresponding pxar metadata (``.mpxar``) archive. Contains a concatenation +of regular file payloads, each prefixed by a `PAYLOAD` header. Further, the +actual referenced payload entries might be separated by padding (full/partial +payloads not referenced), introduced when reusing chunks of a previous backup +run, when chunk boundaries did not aligned to payload entry offsets. + +All headers are stored as little-endian. + +.. list-table:: + :widths: auto + + * - ``PAYLOAD_START_MARKER`` + - header of ``[u8; 16]`` consisting of type hash and size; + marks start + * - ``PAYLOAD`` + - header of ``[u8; 16]`` cosisting of type hash and size; + referenced by metadata archive + * - Payload + - raw regular file payload + * - Padding + - partial/full unreferenced payloads, caused by unaligned chunk boundary + * - ... + - further concatenation of payload header, payload and padding + * - ``PAYLOAD_TAIL_MARKER`` + - header of ``[u8; 16]`` consisting of type hash and size; + marks end .. _data-blob-format: Data Blob Format (``.blob``) diff --git a/docs/meta-format-overview.dot b/docs/meta-format-overview.dot new file mode 100644 index 000000000..7eea4b55b --- /dev/null +++ b/docs/meta-format-overview.dot @@ -0,0 +1,50 @@ +digraph g { +graph [ +rankdir = "LR" +fontname="Helvetica" +]; +node [ +fontsize = "16" +shape = "record" +]; +edge [ +]; + +"archive" [ +label = "archive.mpxar" +shape = "record" +]; + +"rootdir" [ +label = "FORMAT_VERSION\l|PRELUDE\l|ENTRY\l|\{XATTR\}\* extended attribute list\l|\{ACL_USER\}\* USER ACL entries\l|\{ACL_GROUP\}\* GROUP ACL entries\l|\[ACL_GROUP_OBJ\] the ACL_GROUP_OBJ \l|\[ACL_DEFAULT\] the various default ACL fields\l|\{ACL_DEFAULT_USER\}\* USER ACL entries\l|\{ACL_DEFAULT_GROUP\}\* GROUP ACL entries\l|\[FCAPS\] file capability in Linux disk format\l|\[QUOTA_PROJECT_ID\] the ext4/xfs quota project ID\l|{ PAYLOAD_REF|SYMLINK|DEVICE|{ \{DirectoryEntries\}\*|GOODBYE}}" +shape = "record" +]; + + +"entry" [ +label = " size: u64 = 64\l|type: u64 = ENTRY\l|feature_flags: u64\l|mode: u64\l|flags: u64\l|uid: u64\l|gid: u64\l|mtime: u64\l" +labeljust = "l" +shape = "record" +]; + + + +"direntry" [ +label = " FILENAME\l|{ENTRY\l|HARDLINK\l}" +shape = "record" +]; + +"payloadrefentry" [ +label = " offset: u64\l|size: u64\l" +shape = "record" +]; + +"archive" -> "rootdir":fv + +"rootdir":f0 -> "entry":f0 + +"rootdir":de -> "direntry":f0 + +"rootdir":pl -> "payloadrefentry":f0 + +} -- 2.39.2 _______________________________________________ pbs-devel mailing list pbs-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel