From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 950289EEFB for ; Wed, 7 Jun 2023 15:30:56 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 7E07B1A33B for ; Wed, 7 Jun 2023 15:30:56 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS for ; Wed, 7 Jun 2023 15:30:55 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 2CDAD41EB0 for ; Wed, 7 Jun 2023 15:30:55 +0200 (CEST) From: Christian Ebner To: pbs-devel@lists.proxmox.com Date: Wed, 7 Jun 2023 15:30:26 +0200 Message-Id: <20230607133027.202575-2-c.ebner@proxmox.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230607133027.202575-1-c.ebner@proxmox.com> References: <20230607133027.202575-1-c.ebner@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL -0.016 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_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 proxmox-backup 1/2] fix: #4761: unlink existing entries for hard/symlinks when overwrite 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: , X-List-Received-Date: Wed, 07 Jun 2023 13:30:56 -0000 Creating symlinks or hardlinks might fail if a directory entry with the same name is already present on the filesystem during restore. When the overwrite flag is given, on failure unlink the existing entry (except directories) and retry hard/symlink creation. Signed-off-by: Christian Ebner --- pbs-client/src/pxar/extract.rs | 39 +++++++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 3 deletions(-) diff --git a/pbs-client/src/pxar/extract.rs b/pbs-client/src/pxar/extract.rs index f6c1991f..14f9b43d 100644 --- a/pbs-client/src/pxar/extract.rs +++ b/pbs-client/src/pxar/extract.rs @@ -326,7 +326,21 @@ impl Extractor { link: &OsStr, ) -> Result<(), Error> { let parent = self.parent_fd()?; - nix::unistd::symlinkat(link, Some(parent), file_name)?; + + match nix::unistd::symlinkat(link, Some(parent), file_name) { + Ok(()) => {} + Err(nix::errno::Errno::EEXIST) => { + if !self.overwrite { + return Err(nix::errno::Errno::EEXIST.into()); + } + // Never unlink directories + let flag = nix::unistd::UnlinkatFlags::NoRemoveDir; + nix::unistd::unlinkat(Some(parent), file_name, flag)?; + nix::unistd::symlinkat(link, Some(parent), file_name)?; + } + Err(err) => return Err(err.into()) + } + metadata::apply_at( self.feature_flags, metadata, @@ -343,13 +357,32 @@ impl Extractor { let parent = self.parent_fd()?; let root = self.dir_stack.root_dir_fd()?; let target = CString::new(link.as_bytes())?; - nix::unistd::linkat( + + match nix::unistd::linkat( Some(root.as_raw_fd()), target.as_c_str(), Some(parent), file_name, nix::unistd::LinkatFlags::NoSymlinkFollow, - )?; + ) { + Ok(()) => {} + Err(nix::errno::Errno::EEXIST) => { + if !self.overwrite { + return Err(nix::errno::Errno::EEXIST.into()); + } + // Never unlink directories + let flag = nix::unistd::UnlinkatFlags::NoRemoveDir; + nix::unistd::unlinkat(Some(parent), file_name, flag)?; + nix::unistd::linkat( + Some(root.as_raw_fd()), + target.as_c_str(), + Some(parent), + file_name, + nix::unistd::LinkatFlags::NoSymlinkFollow, + )?; + } + Err(err) => return Err(err.into()) + } Ok(()) } -- 2.39.2