* [pbs-devel] [PATCH v3 proxmox] Add tempfile() helper function
@ 2020-08-13 14:56 Mira Limbeck
2020-08-13 14:56 ` [pbs-devel] [PATCH v3 proxmox-backup] Replace all occurences of open() with O_TMPFILE Mira Limbeck
0 siblings, 1 reply; 2+ messages in thread
From: Mira Limbeck @ 2020-08-13 14:56 UTC (permalink / raw)
To: pbs-devel
The tempfile() helper function tries to create a temporary file in /tmp
with the O_TMPFILE option. If that fails it falls back to using
mkstemp().
As O_TMPFILE was introduced in kernel 3.11 this fallback can help with
CentOS 7 and its 3.10 kernel as well as with WSL (Windows Subsystem for
Linux).
Signed-off-by: Mira Limbeck <m.limbeck@proxmox.com>
---
v3:
- O_TMPFILE support is tested on first run of tempfile()
- EISDIR is handled specifically to test for O_TMPFILE support
- AtomicBool is used as it provides a safe interface, but 'static mut'
could also be used
- mkstemp() now creates the tempfile in a subdirectory called
proxmox-backup-<UID>
proxmox/src/tools/fs.rs | 62 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 60 insertions(+), 2 deletions(-)
diff --git a/proxmox/src/tools/fs.rs b/proxmox/src/tools/fs.rs
index b1a95b5..0a12254 100644
--- a/proxmox/src/tools/fs.rs
+++ b/proxmox/src/tools/fs.rs
@@ -1,17 +1,20 @@
//! File related utilities such as `replace_file`.
use std::ffi::CStr;
-use std::fs::{File, OpenOptions};
+use std::fs::{DirBuilder, File, OpenOptions};
use std::io::{self, BufRead, BufReader, Write};
+use std::os::unix::fs::{DirBuilderExt, OpenOptionsExt};
use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
use std::path::Path;
+use std::sync::atomic::{AtomicBool, Ordering};
use std::time::Duration;
use anyhow::{bail, format_err, Error};
+use lazy_static::lazy_static;
use nix::errno::Errno;
use nix::fcntl::OFlag;
use nix::sys::stat;
-use nix::unistd::{self, Gid, Uid};
+use nix::unistd::{self, mkstemp, unlink, Gid, Uid};
use serde_json::Value;
use crate::sys::error::SysResult;
@@ -518,3 +521,58 @@ pub fn open_file_locked<P: AsRef<Path>>(path: P, timeout: Duration) -> Result<Fi
Err(err) => bail!("Unable to acquire lock {:?} - {}", path, err),
}
}
+
+static O_TMPFILE_SUPPORT: AtomicBool = AtomicBool::new(true);
+lazy_static! {
+ static ref MKSTEMP_PATH: String = {
+ use nix::unistd::geteuid;
+ let uid = geteuid();
+ format!("/tmp/proxmox-backup-{}", uid)
+ };
+ static ref MKSTEMP_FILE: String = {
+ format!("{}/tmpfile_XXXXXX", MKSTEMP_PATH.as_str())
+ };
+}
+
+/// Create a new tempfile by using O_TMPFILE with a fallback to mkstemp() if it fails (e.g. not supported).
+pub fn tempfile() -> Result<File, Error> {
+ if O_TMPFILE_SUPPORT.load(Ordering::Relaxed) {
+ match std::fs::OpenOptions::new()
+ .write(true)
+ .read(true)
+ .custom_flags(libc::O_TMPFILE)
+ .open("/tmp")
+ {
+ Ok(file) => return Ok(file),
+ Err(err) => {
+ let raw_os_error = match err.raw_os_error() {
+ Some(v) => v,
+ None => -1,
+ };
+ if raw_os_error == 21 {
+ O_TMPFILE_SUPPORT.store(false, Ordering::Relaxed);
+ eprintln!(
+ "Error creating tempfile: 'EISDIR', falling back to mkstemp() instead",
+ );
+ } else {
+ bail!("Error creating tempfile: '{}'", err);
+ }
+ }
+ }
+ }
+
+
+ match DirBuilder::new().recursive(true).mode(0o700).create(MKSTEMP_PATH.as_str()) {
+ Err(err) => {
+ if err.kind() != std::io::ErrorKind::AlreadyExists {
+ bail!("Error creating directory: '{}'", MKSTEMP_PATH.as_str());
+ }
+ // ignore EEXISTS
+ },
+ _ => {},
+ }
+ let (fd, path) = mkstemp(MKSTEMP_FILE.as_str())?;
+ unlink(path.as_path())?;
+ let file = unsafe { File::from_raw_fd(fd) };
+ Ok(file)
+}
--
2.20.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* [pbs-devel] [PATCH v3 proxmox-backup] Replace all occurences of open() with O_TMPFILE
2020-08-13 14:56 [pbs-devel] [PATCH v3 proxmox] Add tempfile() helper function Mira Limbeck
@ 2020-08-13 14:56 ` Mira Limbeck
0 siblings, 0 replies; 2+ messages in thread
From: Mira Limbeck @ 2020-08-13 14:56 UTC (permalink / raw)
To: pbs-devel
with the tempfile() helper function from proxmox::tools. This abstracts
away the open() and adds a fallback to mkstemp() should open() with
O_TMPFILE fail.
This helps in getting the backup client to work under WSL (Windows
Subsystem for Linux).
Signed-off-by: Mira Limbeck <m.limbeck@proxmox.com>
---
This requires the tempfile() addition in the proxmox crate to work.
v3:
- no changes
src/bin/proxmox_backup_client/catalog.rs | 20 ++++----------------
src/client/backup_reader.rs | 21 ++++-----------------
src/client/backup_writer.rs | 15 +++------------
3 files changed, 11 insertions(+), 45 deletions(-)
diff --git a/src/bin/proxmox_backup_client/catalog.rs b/src/bin/proxmox_backup_client/catalog.rs
index b419728e..15df232b 100644
--- a/src/bin/proxmox_backup_client/catalog.rs
+++ b/src/bin/proxmox_backup_client/catalog.rs
@@ -1,4 +1,3 @@
-use std::os::unix::fs::OpenOptionsExt;
use std::io::{Seek, SeekFrom};
use std::sync::Arc;
@@ -6,6 +5,7 @@ use anyhow::{bail, format_err, Error};
use serde_json::Value;
use proxmox::api::{api, cli::*};
+use proxmox::tools::fs::tempfile;
use proxmox_backup::tools;
@@ -103,11 +103,7 @@ async fn dump_catalog(param: Value) -> Result<Value, Error> {
let mut reader = BufferedDynamicReader::new(index, chunk_reader);
- let mut catalogfile = std::fs::OpenOptions::new()
- .write(true)
- .read(true)
- .custom_flags(libc::O_TMPFILE)
- .open("/tmp")?;
+ let mut catalogfile = tempfile()?;
std::io::copy(&mut reader, &mut catalogfile)
.map_err(|err| format_err!("unable to download catalog - {}", err))?;
@@ -192,11 +188,7 @@ async fn catalog_shell(param: Value) -> Result<(), Error> {
true,
).await?;
- let mut tmpfile = std::fs::OpenOptions::new()
- .write(true)
- .read(true)
- .custom_flags(libc::O_TMPFILE)
- .open("/tmp")?;
+ let mut tmpfile = tempfile()?;
let (manifest, _) = client.download_manifest().await?;
@@ -224,11 +216,7 @@ async fn catalog_shell(param: Value) -> Result<(), Error> {
let file_info = manifest.lookup_file_info(&CATALOG_NAME)?;
let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config, file_info.chunk_crypt_mode(), most_used);
let mut reader = BufferedDynamicReader::new(index, chunk_reader);
- let mut catalogfile = std::fs::OpenOptions::new()
- .write(true)
- .read(true)
- .custom_flags(libc::O_TMPFILE)
- .open("/tmp")?;
+ let mut catalogfile = tempfile()?;
std::io::copy(&mut reader, &mut catalogfile)
.map_err(|err| format_err!("unable to download catalog - {}", err))?;
diff --git a/src/client/backup_reader.rs b/src/client/backup_reader.rs
index d4185716..45370141 100644
--- a/src/client/backup_reader.rs
+++ b/src/client/backup_reader.rs
@@ -2,13 +2,12 @@ use anyhow::{format_err, Error};
use std::io::{Read, Write, Seek, SeekFrom};
use std::fs::File;
use std::sync::Arc;
-use std::os::unix::fs::OpenOptionsExt;
use chrono::{DateTime, Utc};
use futures::future::AbortHandle;
use serde_json::{json, Value};
-use proxmox::tools::digest_to_hex;
+use proxmox::tools::{digest_to_hex, fs::tempfile};
use crate::backup::*;
@@ -148,11 +147,7 @@ impl BackupReader {
name: &str,
) -> Result<DataBlobReader<File>, Error> {
- let mut tmpfile = std::fs::OpenOptions::new()
- .write(true)
- .read(true)
- .custom_flags(libc::O_TMPFILE)
- .open("/tmp")?;
+ let mut tmpfile = tempfile()?;
self.download(name, &mut tmpfile).await?;
@@ -174,11 +169,7 @@ impl BackupReader {
name: &str,
) -> Result<DynamicIndexReader, Error> {
- let mut tmpfile = std::fs::OpenOptions::new()
- .write(true)
- .read(true)
- .custom_flags(libc::O_TMPFILE)
- .open("/tmp")?;
+ let mut tmpfile = tempfile()?;
self.download(name, &mut tmpfile).await?;
@@ -202,11 +193,7 @@ impl BackupReader {
name: &str,
) -> Result<FixedIndexReader, Error> {
- let mut tmpfile = std::fs::OpenOptions::new()
- .write(true)
- .read(true)
- .custom_flags(libc::O_TMPFILE)
- .open("/tmp")?;
+ let mut tmpfile = tempfile()?;
self.download(name, &mut tmpfile).await?;
diff --git a/src/client/backup_writer.rs b/src/client/backup_writer.rs
index 38686f67..e04ad56a 100644
--- a/src/client/backup_writer.rs
+++ b/src/client/backup_writer.rs
@@ -1,5 +1,4 @@
use std::collections::HashSet;
-use std::os::unix::fs::OpenOptionsExt;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::{Arc, Mutex};
@@ -12,7 +11,7 @@ use serde_json::{json, Value};
use tokio::io::AsyncReadExt;
use tokio::sync::{mpsc, oneshot};
-use proxmox::tools::digest_to_hex;
+use proxmox::tools::{digest_to_hex, fs::tempfile};
use super::merge_known_chunks::{MergedChunkInfo, MergeKnownChunks};
use crate::backup::*;
@@ -408,11 +407,7 @@ impl BackupWriter {
known_chunks: Arc<Mutex<HashSet<[u8;32]>>>,
) -> Result<FixedIndexReader, Error> {
- let mut tmpfile = std::fs::OpenOptions::new()
- .write(true)
- .read(true)
- .custom_flags(libc::O_TMPFILE)
- .open("/tmp")?;
+ let mut tmpfile = tempfile()?;
let param = json!({ "archive-name": archive_name });
self.h2.download("previous", Some(param), &mut tmpfile).await?;
@@ -443,11 +438,7 @@ impl BackupWriter {
known_chunks: Arc<Mutex<HashSet<[u8;32]>>>,
) -> Result<DynamicIndexReader, Error> {
- let mut tmpfile = std::fs::OpenOptions::new()
- .write(true)
- .read(true)
- .custom_flags(libc::O_TMPFILE)
- .open("/tmp")?;
+ let mut tmpfile = tempfile()?;
let param = json!({ "archive-name": archive_name });
self.h2.download("previous", Some(param), &mut tmpfile).await?;
--
2.20.1
^ permalink raw reply [flat|nested] 2+ messages in thread
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