From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dcsapak@zita.proxmox.com>
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 4971060EEA
 for <pbs-devel@lists.proxmox.com>; Fri, 25 Sep 2020 16:14:01 +0200 (CEST)
Received: from firstgate.proxmox.com (localhost [127.0.0.1])
 by firstgate.proxmox.com (Proxmox) with ESMTP id 3E72C1C1BA
 for <pbs-devel@lists.proxmox.com>; Fri, 25 Sep 2020 16:13:31 +0200 (CEST)
Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com
 [212.186.127.180])
 (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 id 1F7B41C16C
 for <pbs-devel@lists.proxmox.com>; Fri, 25 Sep 2020 16:13:29 +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 D35EB45791
 for <pbs-devel@lists.proxmox.com>; Fri, 25 Sep 2020 16:13:28 +0200 (CEST)
From: Dominik Csapak <d.csapak@proxmox.com>
To: pbs-devel@lists.proxmox.com
Date: Fri, 25 Sep 2020 16:13:14 +0200
Message-Id: <20200925141327.25024-2-d.csapak@proxmox.com>
X-Mailer: git-send-email 2.20.1
In-Reply-To: <20200925141327.25024-1-d.csapak@proxmox.com>
References: <20200925141327.25024-1-d.csapak@proxmox.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
X-SPAM-LEVEL: Spam detection results:  0
 AWL -0.175 Adjusted score from AWL reputation of From: address
 KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment
 KAM_LAZY_DOMAIN_SECURITY 1 Sending domain does not have any anti-forgery
 methods
 NO_DNS_FOR_FROM         0.379 Envelope sender has no MX or A DNS records
 RCVD_IN_DNSWL_MED        -2.3 Sender listed at https://www.dnswl.org/,
 medium trust
 SPF_HELO_NONE           0.001 SPF: HELO does not publish an SPF Record
 SPF_NONE                0.001 SPF: sender does not publish an SPF Record
 URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See
 http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more
 information. [fs.rs]
Subject: [pbs-devel] [PATCH proxmox 1/3] proxmox/tools/fs: add shared lock
 helper
X-BeenThere: pbs-devel@lists.proxmox.com
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Proxmox Backup Server development discussion
 <pbs-devel.lists.proxmox.com>
List-Unsubscribe: <https://lists.proxmox.com/cgi-bin/mailman/options/pbs-devel>, 
 <mailto:pbs-devel-request@lists.proxmox.com?subject=unsubscribe>
List-Archive: <http://lists.proxmox.com/pipermail/pbs-devel/>
List-Post: <mailto:pbs-devel@lists.proxmox.com>
List-Help: <mailto:pbs-devel-request@lists.proxmox.com?subject=help>
List-Subscribe: <https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel>, 
 <mailto:pbs-devel-request@lists.proxmox.com?subject=subscribe>
X-List-Received-Date: Fri, 25 Sep 2020 14:14:01 -0000

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
 proxmox/src/tools/fs.rs | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/proxmox/src/tools/fs.rs b/proxmox/src/tools/fs.rs
index b1a95b5..2cd1a1b 100644
--- a/proxmox/src/tools/fs.rs
+++ b/proxmox/src/tools/fs.rs
@@ -505,15 +505,26 @@ pub fn lock_file<F: AsRawFd>(
     Ok(())
 }
 
+/// Open or create a lock file (append mode). Then try to
+/// acquire a shared lock using `lock_file()`.
+pub fn open_file_locked_shared<P: AsRef<Path>>(path: P, timeout: Duration) -> Result<File, Error> {
+    open_file_locked_impl(path, timeout, false)
+}
+
 /// Open or create a lock file (append mode). Then try to
 /// acquire a lock using `lock_file()`.
 pub fn open_file_locked<P: AsRef<Path>>(path: P, timeout: Duration) -> Result<File, Error> {
+    open_file_locked_impl(path, timeout, true)
+}
+
+fn open_file_locked_impl<P: AsRef<Path>>(path: P, timeout: Duration, exclusive: bool) -> Result<File, Error> {
+
     let path = path.as_ref();
     let mut file = match OpenOptions::new().create(true).append(true).open(path) {
         Ok(file) => file,
         Err(err) => bail!("Unable to open lock {:?} - {}", path, err),
     };
-    match lock_file(&mut file, true, Some(timeout)) {
+    match lock_file(&mut file, exclusive, Some(timeout)) {
         Ok(_) => Ok(file),
         Err(err) => bail!("Unable to acquire lock {:?} - {}", path, err),
     }
-- 
2.20.1