* [pbs-devel] [PATCH proxmox] sys: file: use renameat2() from `nix` crate
@ 2024-07-11 17:07 Christoph Heiss
2024-07-11 17:11 ` Turkijan
2024-07-12 7:37 ` Christian Ebner
0 siblings, 2 replies; 5+ messages in thread
From: Christoph Heiss @ 2024-07-11 17:07 UTC (permalink / raw)
To: pbs-devel
Saves us from converting the paths to raw C strings ourselves, thus
simplifying it quite a bit.
No functional changes.
Signed-off-by: Christoph Heiss <c.heiss@proxmox.com>
---
proxmox-sys/src/fs/file.rs | 51 ++++++++++++++++----------------------
1 file changed, 22 insertions(+), 29 deletions(-)
diff --git a/proxmox-sys/src/fs/file.rs b/proxmox-sys/src/fs/file.rs
index ac513891..3b20c4ea 100644
--- a/proxmox-sys/src/fs/file.rs
+++ b/proxmox-sys/src/fs/file.rs
@@ -10,7 +10,6 @@ use nix::errno::Errno;
use nix::fcntl::OFlag;
use nix::sys::stat;
use nix::unistd;
-use nix::NixPath;
use serde_json::Value;
use proxmox_lang::try_block;
@@ -266,30 +265,32 @@ pub fn atomic_open_or_create_file<P: AsRef<Path>>(
// rotate the file into place, but use `RENAME_NOREPLACE`, so in case 2 processes race against
// the initialization, the first one wins!
- let rename_result = temp_file_name.with_nix_path(|c_file_name| {
- path.with_nix_path(|new_path| unsafe {
- // This also works on file systems which don't support hardlinks (eg. vfat)
- match Errno::result(libc::renameat2(
- libc::AT_FDCWD,
- c_file_name.as_ptr(),
- libc::AT_FDCWD,
- new_path.as_ptr(),
- libc::RENAME_NOREPLACE,
- )) {
- Err(Errno::EINVAL) => (), // dumb file system, try `link`+`unlink`
- other => return other,
- };
- // but some file systems don't support `RENAME_NOREPLACE`
+ let rename_result = match nix::fcntl::renameat2(
+ None, // AT_FDCWD
+ &temp_file_name,
+ None, // AT_FDCWD
+ path,
+ nix::fcntl::RenameFlags::RENAME_NOREPLACE,
+ ) {
+ Err(Errno::EINVAL) => {
+ // some file systems don't support `RENAME_NOREPLACE`
// so we just use `link` + `unlink` instead
- let result = Errno::result(libc::link(c_file_name.as_ptr(), new_path.as_ptr()));
- let _ = libc::unlink(c_file_name.as_ptr());
+ let result = nix::unistd::linkat(
+ None,
+ &temp_file_name,
+ None,
+ &path.to_path_buf(),
+ nix::unistd::LinkatFlags::NoSymlinkFollow,
+ );
+ let _ = nix::unistd::unlink(&temp_file_name);
result
- })
- });
+ }
+ other => other,
+ };
match rename_result {
- Ok(Ok(Ok(_))) => Ok(file),
- Ok(Ok(Err(err))) => {
+ Ok(_) => Ok(file),
+ Err(err) => {
// if another process has already raced ahead and created
// the file, let's just open theirs instead:
let _ = nix::unistd::unlink(&temp_file_name);
@@ -308,14 +309,6 @@ pub fn atomic_open_or_create_file<P: AsRef<Path>>(
);
}
}
- Ok(Err(err)) => {
- let _ = nix::unistd::unlink(&temp_file_name);
- bail!("with_nix_path {:?} failed - {}", path, err);
- }
- Err(err) => {
- let _ = nix::unistd::unlink(&temp_file_name);
- bail!("with_nix_path {:?} failed - {}", temp_file_name, err);
- }
}
}
--
2.45.1
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [pbs-devel] [PATCH proxmox] sys: file: use renameat2() from `nix` crate
2024-07-11 17:07 [pbs-devel] [PATCH proxmox] sys: file: use renameat2() from `nix` crate Christoph Heiss
@ 2024-07-11 17:11 ` Turkijan
2024-07-11 19:39 ` Dietmar Maurer
2024-07-12 7:37 ` Christian Ebner
1 sibling, 1 reply; 5+ messages in thread
From: Turkijan @ 2024-07-11 17:11 UTC (permalink / raw)
To: Proxmox Backup Server development discussion
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Have you changed dev package?
On Thu, Jul 11, 2024 at 1:08 PM Christoph Heiss <c.heiss@proxmox.com> wrote:
> Saves us from converting the paths to raw C strings ourselves, thus
> simplifying it quite a bit.
>
> No functional changes.
>
> Signed-off-by: Christoph Heiss <c.heiss@proxmox.com>
> ---
> proxmox-sys/src/fs/file.rs | 51 ++++++++++++++++----------------------
> 1 file changed, 22 insertions(+), 29 deletions(-)
>
> diff --git a/proxmox-sys/src/fs/file.rs b/proxmox-sys/src/fs/file.rs
> index ac513891..3b20c4ea 100644
> --- a/proxmox-sys/src/fs/file.rs
> +++ b/proxmox-sys/src/fs/file.rs
> @@ -10,7 +10,6 @@ use nix::errno::Errno;
> use nix::fcntl::OFlag;
> use nix::sys::stat;
> use nix::unistd;
> -use nix::NixPath;
> use serde_json::Value;
>
> use proxmox_lang::try_block;
> @@ -266,30 +265,32 @@ pub fn atomic_open_or_create_file<P: AsRef<Path>>(
>
> // rotate the file into place, but use `RENAME_NOREPLACE`, so in case
> 2 processes race against
> // the initialization, the first one wins!
> - let rename_result = temp_file_name.with_nix_path(|c_file_name| {
> - path.with_nix_path(|new_path| unsafe {
> - // This also works on file systems which don't support
> hardlinks (eg. vfat)
> - match Errno::result(libc::renameat2(
> - libc::AT_FDCWD,
> - c_file_name.as_ptr(),
> - libc::AT_FDCWD,
> - new_path.as_ptr(),
> - libc::RENAME_NOREPLACE,
> - )) {
> - Err(Errno::EINVAL) => (), // dumb file system, try
> `link`+`unlink`
> - other => return other,
> - };
> - // but some file systems don't support `RENAME_NOREPLACE`
> + let rename_result = match nix::fcntl::renameat2(
> + None, // AT_FDCWD
> + &temp_file_name,
> + None, // AT_FDCWD
> + path,
> + nix::fcntl::RenameFlags::RENAME_NOREPLACE,
> + ) {
> + Err(Errno::EINVAL) => {
> + // some file systems don't support `RENAME_NOREPLACE`
> // so we just use `link` + `unlink` instead
> - let result = Errno::result(libc::link(c_file_name.as_ptr(),
> new_path.as_ptr()));
> - let _ = libc::unlink(c_file_name.as_ptr());
> + let result = nix::unistd::linkat(
> + None,
> + &temp_file_name,
> + None,
> + &path.to_path_buf(),
> + nix::unistd::LinkatFlags::NoSymlinkFollow,
> + );
> + let _ = nix::unistd::unlink(&temp_file_name);
> result
> - })
> - });
> + }
> + other => other,
> + };
>
> match rename_result {
> - Ok(Ok(Ok(_))) => Ok(file),
> - Ok(Ok(Err(err))) => {
> + Ok(_) => Ok(file),
> + Err(err) => {
> // if another process has already raced ahead and created
> // the file, let's just open theirs instead:
> let _ = nix::unistd::unlink(&temp_file_name);
> @@ -308,14 +309,6 @@ pub fn atomic_open_or_create_file<P: AsRef<Path>>(
> );
> }
> }
> - Ok(Err(err)) => {
> - let _ = nix::unistd::unlink(&temp_file_name);
> - bail!("with_nix_path {:?} failed - {}", path, err);
> - }
> - Err(err) => {
> - let _ = nix::unistd::unlink(&temp_file_name);
> - bail!("with_nix_path {:?} failed - {}", temp_file_name, err);
> - }
> }
> }
>
> --
> 2.45.1
>
>
>
> _______________________________________________
> pbs-devel mailing list
> pbs-devel@lists.proxmox.com
> https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel
>
>
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [pbs-devel] [PATCH proxmox] sys: file: use renameat2() from `nix` crate
2024-07-11 17:07 [pbs-devel] [PATCH proxmox] sys: file: use renameat2() from `nix` crate Christoph Heiss
2024-07-11 17:11 ` Turkijan
@ 2024-07-12 7:37 ` Christian Ebner
2024-07-12 7:44 ` Christoph Heiss
1 sibling, 1 reply; 5+ messages in thread
From: Christian Ebner @ 2024-07-12 7:37 UTC (permalink / raw)
To: Proxmox Backup Server development discussion, Christoph Heiss
one small nit inline:
> On 11.07.2024 19:07 CEST Christoph Heiss <c.heiss@proxmox.com> wrote:
>
>
> Saves us from converting the paths to raw C strings ourselves, thus
> simplifying it quite a bit.
>
> No functional changes.
>
> Signed-off-by: Christoph Heiss <c.heiss@proxmox.com>
> ---
> proxmox-sys/src/fs/file.rs | 51 ++++++++++++++++----------------------
> 1 file changed, 22 insertions(+), 29 deletions(-)
>
> diff --git a/proxmox-sys/src/fs/file.rs b/proxmox-sys/src/fs/file.rs
> index ac513891..3b20c4ea 100644
> --- a/proxmox-sys/src/fs/file.rs
> +++ b/proxmox-sys/src/fs/file.rs
> @@ -10,7 +10,6 @@ use nix::errno::Errno;
> use nix::fcntl::OFlag;
> use nix::sys::stat;
> use nix::unistd;
> -use nix::NixPath;
> use serde_json::Value;
>
> use proxmox_lang::try_block;
> @@ -266,30 +265,32 @@ pub fn atomic_open_or_create_file<P: AsRef<Path>>(
>
> // rotate the file into place, but use `RENAME_NOREPLACE`, so in case 2 processes race against
> // the initialization, the first one wins!
> - let rename_result = temp_file_name.with_nix_path(|c_file_name| {
> - path.with_nix_path(|new_path| unsafe {
> - // This also works on file systems which don't support hardlinks (eg. vfat)
> - match Errno::result(libc::renameat2(
> - libc::AT_FDCWD,
> - c_file_name.as_ptr(),
> - libc::AT_FDCWD,
> - new_path.as_ptr(),
> - libc::RENAME_NOREPLACE,
> - )) {
> - Err(Errno::EINVAL) => (), // dumb file system, try `link`+`unlink`
> - other => return other,
> - };
> - // but some file systems don't support `RENAME_NOREPLACE`
> + let rename_result = match nix::fcntl::renameat2(
> + None, // AT_FDCWD
> + &temp_file_name,
> + None, // AT_FDCWD
> + path,
> + nix::fcntl::RenameFlags::RENAME_NOREPLACE,
> + ) {
> + Err(Errno::EINVAL) => {
> + // some file systems don't support `RENAME_NOREPLACE`
> // so we just use `link` + `unlink` instead
> - let result = Errno::result(libc::link(c_file_name.as_ptr(), new_path.as_ptr()));
> - let _ = libc::unlink(c_file_name.as_ptr());
> + let result = nix::unistd::linkat(
> + None,
> + &temp_file_name,
> + None,
> + &path.to_path_buf(),
> + nix::unistd::LinkatFlags::NoSymlinkFollow,
According to https://docs.rs/nix/0.29.0/nix/unistd/type.LinkatFlags.html
`LinkatFlags` will be deprecated with version 0.28. We currently use nix 0.16.1, which already provides the suggested replacment using the `AtFlags` https://docs.rs/nix/0.26.1/nix/fcntl/struct.AtFlags.html.
So it would make sense to already use these instead.
> + );
> + let _ = nix::unistd::unlink(&temp_file_name);
> result
> - })
> - });
> + }
> + other => other,
> + };
>
> match rename_result {
> - Ok(Ok(Ok(_))) => Ok(file),
> - Ok(Ok(Err(err))) => {
> + Ok(_) => Ok(file),
> + Err(err) => {
> // if another process has already raced ahead and created
> // the file, let's just open theirs instead:
> let _ = nix::unistd::unlink(&temp_file_name);
> @@ -308,14 +309,6 @@ pub fn atomic_open_or_create_file<P: AsRef<Path>>(
> );
> }
> }
> - Ok(Err(err)) => {
> - let _ = nix::unistd::unlink(&temp_file_name);
> - bail!("with_nix_path {:?} failed - {}", path, err);
> - }
> - Err(err) => {
> - let _ = nix::unistd::unlink(&temp_file_name);
> - bail!("with_nix_path {:?} failed - {}", temp_file_name, err);
> - }
> }
> }
>
> --
> 2.45.1
>
>
>
> _______________________________________________
> pbs-devel mailing list
> pbs-devel@lists.proxmox.com
> https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel
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^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [pbs-devel] [PATCH proxmox] sys: file: use renameat2() from `nix` crate
2024-07-12 7:37 ` Christian Ebner
@ 2024-07-12 7:44 ` Christoph Heiss
0 siblings, 0 replies; 5+ messages in thread
From: Christoph Heiss @ 2024-07-12 7:44 UTC (permalink / raw)
To: Christian Ebner; +Cc: Proxmox Backup Server development discussion
Thanks for the review!
On Fri, Jul 12, 2024 at 09:37:03AM GMT, Christian Ebner wrote:
> one small nit inline:
> > On 11.07.2024 19:07 CEST Christoph Heiss <c.heiss@proxmox.com> wrote:
> > [..]
> > + // some file systems don't support `RENAME_NOREPLACE`
> > // so we just use `link` + `unlink` instead
> > - let result = Errno::result(libc::link(c_file_name.as_ptr(), new_path.as_ptr()));
> > - let _ = libc::unlink(c_file_name.as_ptr());
> > + let result = nix::unistd::linkat(
> > + None,
> > + &temp_file_name,
> > + None,
> > + &path.to_path_buf(),
> > + nix::unistd::LinkatFlags::NoSymlinkFollow,
>
> According to
> https://docs.rs/nix/0.29.0/nix/unistd/type.LinkatFlags.html
> `LinkatFlags` will be deprecated with version 0.28. We currently use
> nix 0.16.1, which already provides the suggested replacment using the
> `AtFlags` https://docs.rs/nix/0.26.1/nix/fcntl/struct.AtFlags.html.
>
> So it would make sense to already use these instead.
Nice catch! I'll send a v2 :^)
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2024-07-11 17:07 [pbs-devel] [PATCH proxmox] sys: file: use renameat2() from `nix` crate Christoph Heiss
2024-07-11 17:11 ` Turkijan
2024-07-11 19:39 ` Dietmar Maurer
2024-07-12 7:37 ` Christian Ebner
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