//! Bounded dentry lookup and stale mount generation probe.

use super::*;
use os_vfs_lookup::{Error as LookupError, LookupTable, Mount as LookupMount};
use os_vfs_paths::{Mount as PathMount, MountNamespace, PathState};

pub fn run(allocator: &mut memory::FrameAllocator) -> Result<(), &'static str> {
    let frames_before = allocator.remaining_pages();
    let resolver = PathState::new();
    let root = resolver.resolve(b"/sandbox").map_err(|_| "k1555-root")?;
    let first_path = PathMount::new(resolver.resolve(b"/sandbox/veri")
        .map_err(|_| "k1555-first-path")?, 1).map_err(|_| "k1555-first-mount")?;
    let second_path = PathMount::new(resolver.resolve(b"/sandbox/ara")
        .map_err(|_| "k1555-second-path")?, 2).map_err(|_| "k1555-second-mount")?;
    let namespace = MountNamespace::new(root, first_path, second_path)
        .map_err(|_| "k1555-namespace")?;
    let first_route = namespace.resolve(b"/veri/dosya")
        .map_err(|_| "k1555-first-route")?;
    let second_route = namespace.resolve(b"/ara/dosya")
        .map_err(|_| "k1555-second-route")?;
    let first = LookupMount::new(1, 11, b"dosya")
        .map_err(|_| "k1555-first-entry")?;
    let second = LookupMount::new(2, 22, b"dosya")
        .map_err(|_| "k1555-second-entry")?;
    let mut table = LookupTable::new(first, second)
        .map_err(|_| "k1555-table")?;
    let old = table.lookup(first_route.volume, b"dosya")
        .map_err(|_| "k1555-first-lookup")?;
    let other = table.lookup(second_route.volume, b"dosya")
        .map_err(|_| "k1555-second-lookup")?;
    if table.validate(old) != Ok(11) || table.validate(other) != Ok(22)
        || table.active_mounts() != 2 || old.inode == other.inode {
        return Err("k1555-distinct-inodes");
    }
    table.unmount(1).map_err(|_| "k1555-unmount")?;
    if table.validate(old) != Err(LookupError::Stale)
        || table.validate(other) != Ok(22)
        || table.active_mounts() != 1 {
        return Err("k1555-stale-on-unmount");
    }
    table.remount(1).map_err(|_| "k1555-remount")?;
    if table.validate(old) != Err(LookupError::Stale)
        || table.active_mounts() != 2 {
        return Err("k1555-stale-on-remount");
    }
    let fresh = table.lookup(1, b"dosya")
        .map_err(|_| "k1555-fresh-lookup")?;
    if fresh.generation != 2 || table.validate(fresh) != Ok(11)
        || allocator.remaining_pages() != frames_before {
        return Err("k1555-fresh-generation");
    }
    write_line("TURKOS/OS/K1555-LOOKUP: FIRST=11 SECOND=22 STALE=REJECTED REMOUNT=STALE FRESH=2 FRAMES=UNCHANGED");
    Ok(())
}