From: Wedson Almeida Filho <walmeida@xxxxxxxxxxxxx>
Allow Rust file system modules to create inodes that are symlinks,
pipes, sockets, char devices and block devices (in addition to the
already-supported directories and regular files).
Signed-off-by: Wedson Almeida Filho <walmeida@xxxxxxxxxxxxx>
---
rust/helpers.c | 6 +++
rust/kernel/fs.rs | 88 +++++++++++++++++++++++++++++++++++++++
samples/rust/rust_rofs.rs | 9 +++-
3 files changed, 102 insertions(+), 1 deletion(-)
diff --git a/rust/helpers.c b/rust/helpers.c
index f2ce3e7b688c..af335d1912e7 100644
--- a/rust/helpers.c
+++ b/rust/helpers.c
@@ -244,6 +244,12 @@ void rust_helper_mapping_set_large_folios(struct address_space *mapping)
}
EXPORT_SYMBOL_GPL(rust_helper_mapping_set_large_folios);
+unsigned int rust_helper_MKDEV(unsigned int major, unsigned int minor)
+{
+ return MKDEV(major, minor);
+}
+EXPORT_SYMBOL_GPL(rust_helper_MKDEV);
+
/*
* `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can
* use it in contexts where Rust expects a `usize` like slice (array) indices.
diff --git a/rust/kernel/fs.rs b/rust/kernel/fs.rs
index 8f34da50e694..5b7eaa16d254 100644
--- a/rust/kernel/fs.rs
+++ b/rust/kernel/fs.rs
@@ -112,8 +112,13 @@ pub enum DirEntryType {
impl From<INodeType> for DirEntryType {
fn from(value: INodeType) -> Self {
match value {
+ INodeType::Fifo => DirEntryType::Fifo,
+ INodeType::Chr(_, _) => DirEntryType::Chr,
INodeType::Dir => DirEntryType::Dir,
+ INodeType::Blk(_, _) => DirEntryType::Blk,
INodeType::Reg => DirEntryType::Reg,
+ INodeType::Lnk => DirEntryType::Lnk,
+ INodeType::Sock => DirEntryType::Sock,
}
}
}
@@ -281,6 +286,46 @@ pub fn init(self, params: INodeParams) -> Result<ARef<INode<T>>> {
unsafe { bindings::mapping_set_large_folios(inode.i_mapping) };
bindings::S_IFREG
}
+ INodeType::Lnk => {
+ inode.i_op = &Tables::<T>::LNK_INODE_OPERATIONS;
+ inode.i_data.a_ops = &Tables::<T>::FILE_ADDRESS_SPACE_OPERATIONS;
+
+ // SAFETY: `inode` is valid for write as it's a new inode.
+ unsafe { bindings::inode_nohighmem(inode) };
+ bindings::S_IFLNK
+ }
+ INodeType::Fifo => {
+ // SAFETY: `inode` is valid for write as it's a new inode.
+ unsafe { bindings::init_special_inode(inode, bindings::S_IFIFO as _, 0) };
+ bindings::S_IFIFO
+ }
+ INodeType::Sock => {
+ // SAFETY: `inode` is valid for write as it's a new inode.
+ unsafe { bindings::init_special_inode(inode, bindings::S_IFSOCK as _, 0) };
+ bindings::S_IFSOCK
+ }
+ INodeType::Chr(major, minor) => {
+ // SAFETY: `inode` is valid for write as it's a new inode.
+ unsafe {
+ bindings::init_special_inode(
+ inode,
+ bindings::S_IFCHR as _,
+ bindings::MKDEV(major, minor & bindings::MINORMASK),
+ )
+ };
+ bindings::S_IFCHR
+ }
+ INodeType::Blk(major, minor) => {
+ // SAFETY: `inode` is valid for write as it's a new inode.
+ unsafe {
+ bindings::init_special_inode(
+ inode,
+ bindings::S_IFBLK as _,
+ bindings::MKDEV(major, minor & bindings::MINORMASK),
+ )
+ };
+ bindings::S_IFBLK
+ }
};
inode.i_mode = (params.mode & 0o777) | u16::try_from(mode)?;
@@ -315,11 +360,26 @@ fn drop(&mut self) {
/// The type of the inode.
#[derive(Copy, Clone)]
pub enum INodeType {
+ /// Named pipe (first-in, first-out) type.
+ Fifo,
+
+ /// Character device type.
+ Chr(u32, u32),
+
/// Directory type.
Dir,
+ /// Block device type.
+ Blk(u32, u32),
+
/// Regular file type.
Reg,
+
+ /// Symbolic link type.
+ Lnk,
+
+ /// Named unix-domain socket type.
+ Sock,
}
/// Required inode parameters.
@@ -701,6 +761,34 @@ extern "C" fn lookup_callback(
}
}
+ const LNK_INODE_OPERATIONS: bindings::inode_operations = bindings::inode_operations {
+ lookup: None,
+ get_link: Some(bindings::page_get_link),
+ permission: None,
+ get_inode_acl: None,
+ readlink: None,
+ create: None,
+ link: None,
+ unlink: None,
+ symlink: None,
+ mkdir: None,
+ rmdir: None,
+ mknod: None,
+ rename: None,
+ setattr: None,
+ getattr: None,
+ listxattr: None,
+ fiemap: None,
+ update_time: None,
+ atomic_open: None,
+ tmpfile: None,
+ get_acl: None,
+ set_acl: None,
+ fileattr_set: None,
+ fileattr_get: None,
+ get_offset_ctx: None,
+ };
+
const FILE_ADDRESS_SPACE_OPERATIONS: bindings::address_space_operations =
bindings::address_space_operations {
writepage: None,
diff --git a/samples/rust/rust_rofs.rs b/samples/rust/rust_rofs.rs
index ef651ad38185..95ce28efa1c3 100644
--- a/samples/rust/rust_rofs.rs
+++ b/samples/rust/rust_rofs.rs
@@ -23,7 +23,7 @@ struct Entry {
contents: &'static [u8],
}
-const ENTRIES: [Entry; 3] = [
+const ENTRIES: [Entry; 4] = [
Entry {
name: b".",
ino: 1,
@@ -42,6 +42,12 @@ struct Entry {
etype: INodeType::Reg,
contents: b"hello\n",
},
+ Entry {
+ name: b"link.txt",
+ ino: 3,
+ etype: INodeType::Lnk,
+ contents: b"./test.txt",
+ },
];
struct RoFs;
@@ -125,6 +131,7 @@ fn lookup(parent: &INode<Self>, name: &[u8]) -> Result<ARef<INode<Self>>> {
fn read_folio(inode: &INode<Self>, mut folio: LockedFolio<'_>) -> Result {
let data = match inode.ino() {
2 => ENTRIES[2].contents,
+ 3 => ENTRIES[3].contents,
_ => return Err(EINVAL),
};
--
2.34.1
