statfs: fixes for s390x+musl

Author: selfisekai

CHANGELOG.md

@@ -40,6 +40,8 @@ This project adheres to [Semantic Versioning](https://semver.org/).
   ([#1964](https://github.com/nix-rust/nix/pull/1964))
 - Fix: send ETH_P_ALL in htons format 
   ([#1925](https://github.com/nix-rust/nix/pull/1925))
+- Fix `statfs` compilation on s390x with musl libc.
+  ([#1835](https://github.com/nix-rust/nix/pull/1835))
 
 ### Removed
 
@@ -119,7 +121,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
   ([#1824](https://github.com/nix-rust/nix/pull/1824))
 - Workaround XNU bug causing netmasks returned by `getifaddrs` to misbehave.
   ([#1788](https://github.com/nix-rust/nix/pull/1788))
-  
+
 ### Removed
 
 - Removed deprecated error constants and conversions.

src/sys/statfs.rs

@@ -64,7 +64,7 @@ type fs_type_t = u32;
 type fs_type_t = libc::c_ulong;
 #[cfg(all(target_os = "linux", target_arch = "s390x"))]
 type fs_type_t = libc::c_uint;
-#[cfg(all(target_os = "linux", target_env = "musl"))]
+#[cfg(all(target_os = "linux", target_env = "musl", not(target_arch = "s390x")))]
 type fs_type_t = libc::c_ulong;
 #[cfg(all(target_os = "linux", target_env = "uclibc"))]
 type fs_type_t = libc::c_int;
@@ -342,7 +342,7 @@ impl Statfs {
     /// Optimal transfer block size
     #[cfg(any(
         target_os = "android",
-        all(target_os = "linux", target_env = "musl")
+        all(target_os = "linux", target_env = "musl", not(target_arch = "s390x"))
     ))]
     #[cfg_attr(docsrs, doc(cfg(all())))]
     pub fn optimal_transfer_size(&self) -> libc::c_ulong {
@@ -401,7 +401,7 @@ impl Statfs {
 
     /// Size of a block
     // f_bsize on linux: https://github.com/torvalds/linux/blob/master/fs/nfs/super.c#L471
-    #[cfg(all(target_os = "linux", target_env = "musl"))]
+    #[cfg(all(target_os = "linux", target_env = "musl", not(target_arch = "s390x")))]
     #[cfg_attr(docsrs, doc(cfg(all())))]
     pub fn block_size(&self) -> libc::c_ulong {
         self.0.f_bsize
@@ -492,7 +492,7 @@ impl Statfs {
     }
 
     /// Maximum length of filenames
-    #[cfg(all(target_os = "linux", target_env = "musl"))]
+    #[cfg(all(target_os = "linux", target_env = "musl", not(target_arch = "s390x")))]
     #[cfg_attr(docsrs, doc(cfg(all())))]
     pub fn maximum_name_length(&self) -> libc::c_ulong {
         self.0.f_namelen