bootc/0001-tree-wide-Use-cap-std-ext-is_mountpoint-API.patch

From 5013d45effbbb9c6ca0a6405fca894c8dc06e767 Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Fri, 20 Dec 2024 09:27:30 -0500
Subject: [PATCH] tree-wide: Use cap-std-ext is_mountpoint() API

I moved it there a while ago, now we can drop the copy of it
here.

Signed-off-by: Colin Walters <walters@verbum.org>
---
 lib/src/install.rs          |  2 +-
 ostree-ext/src/commit.rs    |  3 +-
 ostree-ext/src/lib.rs       |  1 -
 ostree-ext/src/mountutil.rs | 60 -------------------------------------
 4 files changed, 2 insertions(+), 64 deletions(-)
 delete mode 100644 ostree-ext/src/mountutil.rs

diff --git a/lib/src/install.rs b/lib/src/install.rs
index 5929e4cd..d591672b 100644
--- a/lib/src/install.rs
+++ b/lib/src/install.rs
@@ -1711,7 +1711,7 @@ pub(crate) async fn install_to_filesystem(
 
         tracing::debug!("Root filesystem: {root_path}");
 
-        if let Some(false) = ostree_ext::mountutil::is_mountpoint(&rootfs_fd, ".")? {
+        if let Some(false) = rootfs_fd.is_mountpoint(".")? {
             anyhow::bail!("Not a mountpoint: {root_path}");
         }
         rootfs_fd
diff --git a/ostree-ext/src/commit.rs b/ostree-ext/src/commit.rs
index babe9017..31571d1e 100644
--- a/ostree-ext/src/commit.rs
+++ b/ostree-ext/src/commit.rs
@@ -3,7 +3,6 @@
 //! <https://github.com/ostreedev/ostree-rs-ext/issues/159>
 
 use crate::container_utils::require_ostree_container;
-use crate::mountutil::is_mountpoint;
 use anyhow::Context;
 use anyhow::Result;
 use cap_std::fs::Dir;
@@ -60,7 +59,7 @@ fn clean_subdir(root: &Dir, rootdev: u64) -> Result<()> {
         }
         // Also ignore bind mounts, if we have a new enough kernel with statx()
         // that will tell us.
-        if is_mountpoint(root, &path)?.unwrap_or_default() {
+        if root.is_mountpoint(&path)?.unwrap_or_default() {
             tracing::trace!("Skipping mount point {path:?}");
             continue;
         }
diff --git a/ostree-ext/src/lib.rs b/ostree-ext/src/lib.rs
index b962c8d6..97ec80de 100644
--- a/ostree-ext/src/lib.rs
+++ b/ostree-ext/src/lib.rs
@@ -39,7 +39,6 @@ pub mod diff;
 pub mod ima;
 pub mod keyfileext;
 pub(crate) mod logging;
-pub mod mountutil;
 pub mod ostree_prepareroot;
 pub mod refescape;
 #[doc(hidden)]
diff --git a/ostree-ext/src/mountutil.rs b/ostree-ext/src/mountutil.rs
deleted file mode 100644
index f73cbba2..00000000
--- a/ostree-ext/src/mountutil.rs
+++ /dev/null
@@ -1,60 +0,0 @@
-//! Helpers for interacting with mounts.
-
-use std::os::fd::AsFd;
-use std::path::Path;
-
-use anyhow::Result;
-use cap_std::fs::Dir;
-use cap_std_ext::cap_std;
-
-// Fix musl support
-#[cfg(target_env = "gnu")]
-use libc::STATX_ATTR_MOUNT_ROOT;
-#[cfg(target_env = "musl")]
-const STATX_ATTR_MOUNT_ROOT: libc::c_int = 0x2000;
-
-fn is_mountpoint_impl_statx(root: &Dir, path: &Path) -> Result<Option<bool>> {
-    // https://github.com/systemd/systemd/blob/8fbf0a214e2fe474655b17a4b663122943b55db0/src/basic/mountpoint-util.c#L176
-    use rustix::fs::{AtFlags, StatxFlags};
-
-    // SAFETY(unwrap): We can infallibly convert an i32 into a u64.
-    let mountroot_flag: u64 = STATX_ATTR_MOUNT_ROOT.try_into().unwrap();
-    match rustix::fs::statx(
-        root.as_fd(),
-        path,
-        AtFlags::NO_AUTOMOUNT | AtFlags::SYMLINK_NOFOLLOW,
-        StatxFlags::empty(),
-    ) {
-        Ok(r) => {
-            let present = (r.stx_attributes_mask & mountroot_flag) > 0;
-            Ok(present.then_some(r.stx_attributes & mountroot_flag > 0))
-        }
-        Err(e) if e == rustix::io::Errno::NOSYS => Ok(None),
-        Err(e) => Err(e.into()),
-    }
-}
-
-/// Try to (heuristically) determine if the provided path is a mount root.
-pub fn is_mountpoint(root: &Dir, path: impl AsRef<Path>) -> Result<Option<bool>> {
-    is_mountpoint_impl_statx(root, path.as_ref())
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use cap_std_ext::cap_tempfile;
-
-    #[test]
-    fn test_is_mountpoint() -> Result<()> {
-        let root = cap_std::fs::Dir::open_ambient_dir("/", cap_std::ambient_authority())?;
-        let supported = is_mountpoint(&root, Path::new("/")).unwrap();
-        match supported {
-            Some(r) => assert!(r),
-            // If the host doesn't support statx, ignore this for now
-            None => return Ok(()),
-        }
-        let tmpdir = cap_tempfile::TempDir::new(cap_std::ambient_authority())?;
-        assert!(!is_mountpoint(&tmpdir, Path::new(".")).unwrap().unwrap());
-        Ok(())
-    }
-}
-- 
2.47.0