From 1623baa137adcb7e7c4944ce365692519b292b3a Mon Sep 17 00:00:00 2001
From: Ian Douglas Scott <ian@iandouglasscott.com>
Date: Tue, 8 Aug 2017 10:59:11 -0700
Subject: [PATCH] Implement F_DUPFD in fcntl
---
src/context/context.rs | 17 ++++++++++++++---
src/syscall/fs.rs | 20 +++++++++++++++++---
2 files changed, 31 insertions(+), 6 deletions(-)
diff --git a/src/context/context.rs b/src/context/context.rs
index 56e3e10f..1cf5a900 100644
--- a/src/context/context.rs
+++ b/src/context/context.rs
@@ -244,17 +244,28 @@ impl Context {
/// Add a file to the lowest available slot.
/// Return the file descriptor number or None if no slot was found
pub fn add_file(&self, file: FileDescriptor) -> Option<FileHandle> {
+ self.add_file_min(file, 0)
+ }
+
+ /// Add a file to the lowest available slot greater than or equal to min.
+ /// Return the file descriptor number or None if no slot was found
+ pub fn add_file_min(&self, file: FileDescriptor, min: usize) -> Option<FileHandle> {
let mut files = self.files.lock();
for (i, mut file_option) in files.iter_mut().enumerate() {
- if file_option.is_none() {
+ if file_option.is_none() && i >= min {
*file_option = Some(file);
return Some(FileHandle::from(i));
}
}
let len = files.len();
if len < super::CONTEXT_MAX_FILES {
- files.push(Some(file));
- Some(FileHandle::from(len))
+ if len >= min {
+ files.push(Some(file));
+ Some(FileHandle::from(len))
+ } else {
+ drop(files);
+ self.insert_file(FileHandle::from(min), file)
+ }
} else {
None
}
diff --git a/src/syscall/fs.rs b/src/syscall/fs.rs
index 1de6cedc..168d165c 100644
--- a/src/syscall/fs.rs
+++ b/src/syscall/fs.rs
@@ -8,7 +8,7 @@ use scheme::{self, FileHandle};
use syscall;
use syscall::data::{Packet, Stat};
use syscall::error::*;
-use syscall::flag::{F_GETFD, F_SETFD, F_GETFL, F_SETFL, O_ACCMODE, O_RDONLY, O_WRONLY, MODE_DIR, MODE_FILE, O_CLOEXEC};
+use syscall::flag::{F_GETFD, F_SETFD, F_GETFL, F_SETFL, F_DUPFD, O_ACCMODE, O_RDONLY, O_WRONLY, MODE_DIR, MODE_FILE, O_CLOEXEC};
use context::file::{FileDescriptor, FileDescription};
pub fn file_op(a: usize, fd: FileHandle, c: usize, d: usize) -> Result<usize> {
@@ -287,7 +287,7 @@ pub fn dup(fd: FileHandle, buf: &[u8]) -> Result<FileHandle> {
let contexts = context::contexts();
let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
let context = context_lock.read();
-
+
context.add_file(new_file).ok_or(Error::new(EMFILE))
}
@@ -320,7 +320,7 @@ pub fn fcntl(fd: FileHandle, cmd: usize, arg: usize) -> Result<usize> {
let description = file.description.read();
// Communicate fcntl with scheme
- if cmd != F_GETFD && cmd != F_SETFD {
+ if cmd != F_DUPFD && cmd != F_GETFD && cmd != F_SETFD {
let scheme = {
let schemes = scheme::schemes();
let scheme = schemes.get(description.scheme).ok_or(Error::new(EBADF))?;
@@ -331,9 +331,23 @@ pub fn fcntl(fd: FileHandle, cmd: usize, arg: usize) -> Result<usize> {
// Perform kernel operation if scheme agrees
{
+ if cmd == F_DUPFD {
+ // Not in match because 'files' cannot be locked
+ let new_file = duplicate_file(fd, &[])?;
+
+ let contexts = context::contexts();
+ let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
+ let context = context_lock.read();
+
+ return context.add_file_min(new_file, arg)
+ .ok_or(Error::new(EMFILE))
+ .map(FileHandle::into);
+ }
+
let contexts = context::contexts();
let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
let context = context_lock.read();
+
let mut files = context.files.lock();
match *files.get_mut(fd.into()).ok_or(Error::new(EBADF))? {
Some(ref mut file) => match cmd {
--
GitLab