mg/fat-rs
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

look up inodes by path

Browse source 
also DirEntry::name now no longer returns option invalid chars get
replaced by ?
This commit is contained in:
Moritz Gmeiner 2025-07-31 23:47:45 +02:00
commit 19340bd4ee
6 changed files with 291 additions and 44 deletions
Download patch file Download diff file Expand all files Collapse all files

122
fat-fuse/src/lib.rs
View file

@ -2,9 +2,11 @@ mod fuse;
mod inode;
use std::collections::BTreeMap;
use std::rc::Rc;
use fat_bits::dir::DirEntry;
use fat_bits::{FatFs, SliceLike};
use fxhash::FxHashMap;
use log::debug;
use crate::inode::Inode;
@ -23,6 +25,7 @@ pub struct FatFuse {
ino_by_first_cluster: BTreeMap<u32, u64>,
ino_by_fh: BTreeMap<u64, u64>,
ino_by_path: FxHashMap<Rc<str>, u64>,
}
impl Drop for FatFuse {
@ -35,9 +38,16 @@ impl Drop for FatFuse {
}
println!("ino_by_fh: {}", self.ino_by_fh.len());
println!("ino_by_path: {}", self.ino_by_path.len());
}
}
/// SAFETY
///
/// do NOT leak Rc<str> from this type
unsafe impl Send for FatFuse {}
impl FatFuse {
pub fn new<S>(data: S) -> anyhow::Result<FatFuse>
where
@ -57,6 +67,7 @@ impl FatFuse {
inode_table: BTreeMap::new(),
ino_by_first_cluster: BTreeMap::new(),
ino_by_fh: BTreeMap::new(),
ino_by_path: FxHashMap::default(),
};
// TODO: build and insert root dir inode
@ -126,6 +137,10 @@ impl FatFuse {
}
}
if let Some(old_ino) = self.ino_by_path.insert(new_inode.path(), ino) {
debug!("ejected old {} -> {} path to ino mapping", new_inode.path(), old_ino);
}
new_inode
}
@ -157,13 +172,45 @@ impl FatFuse {
} else {
// does not match removed inode, leave it as is
debug!(
"removed inode with ino {} from table, but it's first cluster pointer to ino {} instead",
"removed inode with ino {} from table, but its first cluster pointed to ino {} instead",
ino, found_ino
);
}
}
}
}
{
let entry = self.ino_by_path.entry(inode.path());
match entry {
std::collections::hash_map::Entry::Vacant(_) => debug!(
"removed inode with ino {} from table, but it's path did not point to any ino",
ino
),
std::collections::hash_map::Entry::Occupied(occupied_entry) => {
let found_ino = *occupied_entry.get();
if found_ino == ino {
// matches our inode, remove it
occupied_entry.remove();
} else {
// does not match removed inode, leave it as is
debug!(
"removed inode with ino {} from table, but its path pointed to ino {} instead",
ino, found_ino
);
}
}
}
}
let Some(parent_inode) = self.get_inode_mut(inode.parent_ino()) else {
panic!("parent inode {} does not exists anymore", inode.parent_ino());
};
// dec refcount
parent_inode.dec_ref_count(1);
}
fn get_inode(&self, ino: u64) -> Option<&Inode> {
@ -174,20 +221,51 @@ impl FatFuse {
self.inode_table.get_mut(&ino)
}
fn get_or_make_inode_by_dir_entry(&mut self, dir_entry: &DirEntry) -> &mut Inode {
if self
.get_inode_by_first_cluster_mut(dir_entry.first_cluster())
.is_some()
fn get_or_make_inode_by_dir_entry(
&mut self,
dir_entry: &DirEntry,
parent_ino: u64,
parent_path: Rc<str>,
) -> &mut Inode {
if dir_entry.first_cluster() != 0
&& self
.get_inode_by_first_cluster_mut(dir_entry.first_cluster())
.is_some()
{
return self
.get_inode_by_first_cluster_mut(dir_entry.first_cluster())
.unwrap();
}
let path = {
let mut path = parent_path.as_ref().to_owned();
if parent_ino != inode::ROOT_INO {
// root inode already has trailing slash
path.push('/');
}
path += &dir_entry.name_string();
path
};
if self.get_inode_by_path_mut(&path).is_some() {
return self.get_inode_by_path_mut(&path).unwrap();
}
// no inode found, make a new one
let ino = self.next_ino();
let inode = Inode::new(&self.fat_fs, dir_entry, ino, self.uid, self.gid);
let Some(parent_inode) = self.get_inode_mut(parent_ino) else {
// TODO: what do we do here? should not happen
panic!("parent_ino {} does not lead to inode", parent_ino);
};
// inc ref of parent
parent_inode.inc_ref_count();
let inode = Inode::new(&self.fat_fs, dir_entry, ino, self.uid, self.gid, path, parent_ino);
self.insert_inode(inode)
}
@ -235,9 +313,9 @@ impl FatFuse {
}
pub fn get_inode_by_fh(&self, fh: u64) -> Option<&Inode> {
let ino = self.ino_by_fh.get(&fh)?;
let ino = *self.ino_by_fh.get(&fh)?;
if let Some(inode) = self.inode_table.get(ino) {
if let Some(inode) = self.get_inode(ino) {
Some(inode)
} else {
debug!("fh {} is mapped to ino {}, but inode is not in table", fh, ino);
@ -247,9 +325,9 @@ impl FatFuse {
}
pub fn get_inode_by_fh_mut(&mut self, fh: u64) -> Option<&mut Inode> {
let ino = self.ino_by_fh.get(&fh)?;
let ino = *self.ino_by_fh.get(&fh)?;
if let Some(inode) = self.inode_table.get_mut(ino) {
if let Some(inode) = self.get_inode_mut(ino) {
Some(inode)
} else {
debug!("fh {} is mapped to ino {}, but inode is not in table", fh, ino);
@ -257,4 +335,28 @@ impl FatFuse {
None
}
}
pub fn get_inode_by_path(&self, path: &str) -> Option<&Inode> {
let ino = *self.ino_by_path.get(path)?;
if let Some(inode) = self.get_inode(ino) {
Some(inode)
} else {
debug!("path {} is mapped to ino {}, but inode is not in table", path, ino);
None
}
}
pub fn get_inode_by_path_mut(&mut self, path: &str) -> Option<&mut Inode> {
let ino = *self.ino_by_path.get(path)?;
if let Some(inode) = self.get_inode_mut(ino) {
Some(inode)
} else {
debug!("path {} is mapped to ino {}, but inode is not in table", path, ino);
None
}
}
}