fs/mem: give fake blocksize/inode number to files

Author: zyuiop

Cargo.toml

@@ -82,8 +82,8 @@ newlib = []
 ## Enable stubbing result values for some system calls.
 ##
 ## For some system calls related to system options in which Hermit does not implement all possible options,
-## return 0 (success) instead of an error when the option is unknown.
-syscall-fake-success = []
+## return 0 (success) instead of an error when the option is unknown ; or return a convincing fake value.
+syscall-fake-values = []
 
 #! ### Platform Features
 

src/fs/mem.rs

@@ -8,6 +8,8 @@ use alloc::sync::Arc;
 use alloc::vec::Vec;
 use core::marker::PhantomData;
 use core::mem::MaybeUninit;
+#[cfg(feature = "syscall-fake-values")]
+use core::sync::atomic::{AtomicU64, Ordering};
 use core::{mem, ptr};
 
 use align_address::Align;
@@ -36,6 +38,9 @@ impl RomFileInner {
 	}
 }
 
+#[cfg(feature = "syscall-fake-values")]
+static VFS_INO_NUM: AtomicU64 = AtomicU64::new(10_000);
+
 pub struct RomFileInterface {
 	/// Position within the file
 	pos: Mutex<usize>,
@@ -306,6 +311,8 @@ impl RomFile {
 			st_atim: t,
 			st_mtim: t,
 			st_ctim: t,
+			#[cfg(feature = "syscall-fake-values")]
+			st_ino: VFS_INO_NUM.fetch_add(1, Ordering::AcqRel),
 			..Default::default()
 		};
 
@@ -361,6 +368,12 @@ impl RamFile {
 			st_atim: t,
 			st_mtim: t,
 			st_ctim: t,
+			#[cfg(feature = "syscall-fake-values")]
+			st_nlink: 1,
+			#[cfg(feature = "syscall-fake-values")]
+			st_blksize: 4096,
+			#[cfg(feature = "syscall-fake-values")]
+			st_ino: VFS_INO_NUM.fetch_add(1, Ordering::AcqRel),
 			..Default::default()
 		};
 

src/syscalls/mod.rs

@@ -717,8 +717,8 @@ pub extern "C" fn sys_fcntl(fd: i32, cmd: i32, arg: i32) -> i32 {
 				.map_or_else(|e| -i32::from(e), |()| 0)
 			},
 		)
-	} else if cfg!(feature = "syscall-fake-success") {
-		warn!("[syscall-fake-success] Unknown fcntl flag {cmd} {arg}, returning 0");
+	} else if cfg!(feature = "syscall-fake-values") {
+		warn!("[syscall-fake-values] Unknown fcntl flag {cmd} {arg}, returning 0");
 		0
 	} else {
 		-i32::from(Errno::Inval)