starnix_core/vfs/
xattr.rs

1// Copyright 2022 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use crate::vfs::{FsStr, FsString, XattrOp, XattrStorage};
6use starnix_rcu::rcu_hash_map::Entry;
7use starnix_rcu::{RcuHashMap, RcuReadScope};
8use starnix_uapi::errors::Errno;
9use starnix_uapi::{errno, error};
10
11pub struct MemoryXattrStorage {
12    // Arbitrary userspace programs can define xattr keys so we use a collision-resistant hasher.
13    xattrs: RcuHashMap<FsString, FsString, std::collections::hash_map::RandomState>,
14}
15
16impl Default for MemoryXattrStorage {
17    fn default() -> Self {
18        Self { xattrs: RcuHashMap::with_hasher(std::collections::hash_map::RandomState::new()) }
19    }
20}
21
22impl XattrStorage for MemoryXattrStorage {
23    fn get_xattr(&self, name: &FsStr) -> Result<FsString, Errno> {
24        self.xattrs.get(&RcuReadScope::new(), name).cloned().ok_or_else(|| errno!(ENODATA))
25    }
26
27    fn set_xattr(&self, name: &FsStr, value: &FsStr, op: XattrOp) -> Result<(), Errno> {
28        let mut xattrs = self.xattrs.lock();
29        match xattrs.entry(name.to_owned()) {
30            Entry::Vacant(_) if op == XattrOp::Replace => return error!(ENODATA),
31            Entry::Occupied(_) if op == XattrOp::Create => return error!(EEXIST),
32            Entry::Vacant(v) => {
33                v.insert(value.to_owned());
34            }
35            Entry::Occupied(mut o) => {
36                o.insert(value.to_owned());
37            }
38        };
39        Ok(())
40    }
41
42    fn remove_xattr(&self, name: &FsStr) -> Result<(), Errno> {
43        let mut xattrs = self.xattrs.lock();
44        if xattrs.remove(name).is_none() {
45            return error!(ENODATA);
46        }
47        Ok(())
48    }
49
50    fn list_xattrs(&self) -> Result<Vec<FsString>, Errno> {
51        Ok(self.xattrs.keys(&RcuReadScope::new()).cloned().collect())
52    }
53}
starnix_core/vfs/xattr.rs

starnix_core/vfs/
xattr.rs
