Rewrite file.c into fs::file

kernel/Makefile

@@ -8,7 +8,6 @@ KERNEL_SOURCES = \
   bio.c \
   fs.c \
   log.c \
-  file.c \
   pipe.c \
   exec.c \
   sysfile.c \

kernel/file.c

@@ -1,182 +0,0 @@
-//
-// Support functions for system calls that involve file descriptors.
-//
-
-#include "types.h"
-#include "riscv.h"
-#include "defs.h"
-#include "param.h"
-#include "fs.h"
-#include "spinlock.h"
-#include "sleeplock.h"
-#include "file.h"
-#include "stat.h"
-#include "proc.h"
-
-struct devsw devsw[NDEV];
-struct {
-  struct spinlock lock;
-  struct file file[NFILE];
-} ftable;
-
-void
-fileinit(void)
-{
-  initlock(&ftable.lock, "ftable");
-}
-
-// Allocate a file structure.
-struct file*
-filealloc(void)
-{
-  struct file *f;
-
-  acquire(&ftable.lock);
-  for(f = ftable.file; f < ftable.file + NFILE; f++){
-    if(f->ref == 0){
-      f->ref = 1;
-      release(&ftable.lock);
-      return f;
-    }
-  }
-  release(&ftable.lock);
-  return 0;
-}
-
-// Increment ref count for file f.
-struct file*
-filedup(struct file *f)
-{
-  acquire(&ftable.lock);
-  if(f->ref < 1)
-    panic("filedup");
-  f->ref++;
-  release(&ftable.lock);
-  return f;
-}
-
-// Close file f.  (Decrement ref count, close when reaches 0.)
-void
-fileclose(struct file *f)
-{
-  struct file ff;
-
-  acquire(&ftable.lock);
-  if(f->ref < 1)
-    panic("fileclose");
-  if(--f->ref > 0){
-    release(&ftable.lock);
-    return;
-  }
-  ff = *f;
-  f->ref = 0;
-  f->type = FD_NONE;
-  release(&ftable.lock);
-
-  if(ff.type == FD_PIPE){
-    pipeclose(ff.pipe, ff.writable);
-  } else if(ff.type == FD_INODE || ff.type == FD_DEVICE){
-    begin_op();
-    iput(ff.ip);
-    end_op();
-  }
-}
-
-// Get metadata about file f.
-// addr is a user virtual address, pointing to a struct stat.
-int
-filestat(struct file *f, uint64 addr)
-{
-  struct proc *p = myproc();
-  struct stat st;
-  
-  if(f->type == FD_INODE || f->type == FD_DEVICE){
-    ilock(f->ip);
-    stati(f->ip, &st);
-    iunlock(f->ip);
-    if(copyout(p->pagetable, addr, (char *)&st, sizeof(st)) < 0)
-      return -1;
-    return 0;
-  }
-  return -1;
-}
-
-// Read from file f.
-// addr is a user virtual address.
-int
-fileread(struct file *f, uint64 addr, int n)
-{
-  int r = 0;
-
-  if(f->readable == 0)
-    return -1;
-
-  if(f->type == FD_PIPE){
-    r = piperead(f->pipe, addr, n);
-  } else if(f->type == FD_DEVICE){
-    if(f->major < 0 || f->major >= NDEV || !devsw[f->major].read)
-      return -1;
-    r = devsw[f->major].read(1, addr, n);
-  } else if(f->type == FD_INODE){
-    ilock(f->ip);
-    if((r = readi(f->ip, 1, addr, f->off, n)) > 0)
-      f->off += r;
-    iunlock(f->ip);
-  } else {
-    panic("fileread");
-  }
-
-  return r;
-}
-
-// Write to file f.
-// addr is a user virtual address.
-int
-filewrite(struct file *f, uint64 addr, int n)
-{
-  int r, ret = 0;
-
-  if(f->writable == 0)
-    return -1;
-
-  if(f->type == FD_PIPE){
-    ret = pipewrite(f->pipe, addr, n);
-  } else if(f->type == FD_DEVICE){
-    if(f->major < 0 || f->major >= NDEV || !devsw[f->major].write)
-      return -1;
-    ret = devsw[f->major].write(1, addr, n);
-  } else if(f->type == FD_INODE){
-    // write a few blocks at a time to avoid exceeding
-    // the maximum log transaction size, including
-    // i-node, indirect block, allocation blocks,
-    // and 2 blocks of slop for non-aligned writes.
-    // this really belongs lower down, since writei()
-    // might be writing a device like the console.
-    int max = ((MAXOPBLOCKS-1-1-2) / 2) * BSIZE;
-    int i = 0;
-    while(i < n){
-      int n1 = n - i;
-      if(n1 > max)
-        n1 = max;
-
-      begin_op();
-      ilock(f->ip);
-      if ((r = writei(f->ip, 1, addr + i, f->off, n1)) > 0)
-        f->off += r;
-      iunlock(f->ip);
-      end_op();
-
-      if(r != n1){
-        // error from writei
-        break;
-      }
-      i += r;
-    }
-    ret = (i == n ? n : -1);
-  } else {
-    panic("filewrite");
-  }
-
-  return ret;
-}
-

kernel/rustkernel/src/console/mod.rs

@@ -84,18 +84,19 @@ pub fn consputc(c: u8) {
 }
 
 /// User write()s to the console go here.
-#[no_mangle]
-pub unsafe extern "C" fn consolewrite(user_src: i32, src: u64, n: i32) -> i32 {
-    for i in 0..n {
-        let mut c = 0i8;
+pub fn consolewrite(user_src: i32, src: u64, n: i32) -> i32 {
+    unsafe {
+        for i in 0..n {
+            let mut c = 0i8;
 
-        if either_copyin(addr_of_mut!(c).cast(), user_src, src + i as u64, 1) == -1 {
-            return i;
-        } else {
-            uartputc(c as u8);
+            if either_copyin(addr_of_mut!(c).cast(), user_src, src + i as u64, 1) == -1 {
+                return i;
+            } else {
+                uartputc(c as u8);
+            }
         }
+        0
     }
-    0
 }
 
 /// User read()s from the console go here.
@@ -103,59 +104,60 @@ pub unsafe extern "C" fn consolewrite(user_src: i32, src: u64, n: i32) -> i32 {
 /// Copy (up to) a whole input line to dst.
 /// user_dst indicates whether dst is a user
 /// or kernel address.
-#[no_mangle]
-pub unsafe extern "C" fn consoleread(user_dst: i32, mut dst: u64, mut n: i32) -> i32 {
-    let target = n;
-    let mut c;
-    let mut cbuf;
+pub fn consoleread(user_dst: i32, mut dst: u64, mut n: i32) -> i32 {
+    unsafe {
+        let target = n;
+        let mut c;
+        let mut cbuf;
 
-    let mut console = cons.lock();
+        let mut console = cons.lock();
 
-    while n > 0 {
-        // Wait until interrupt handler has put
-        // some input into cons.buffer.
-        while console.read_index == console.write_index {
-            if killed(myproc()) != 0 {
-                // cons.lock.unlock();
-                return -1;
+        while n > 0 {
+            // Wait until interrupt handler has put
+            // some input into cons.buffer.
+            while console.read_index == console.write_index {
+                if killed(myproc()) != 0 {
+                    // cons.lock.unlock();
+                    return -1;
+                }
+                // let channel = addr_of_mut!(console.read_index).cast();
+                // console.sleep(channel);
+                sleep_mutex(addr_of_mut!(console.read_index).cast(), &mut console);
             }
-            // let channel = addr_of_mut!(console.read_index).cast();
-            // console.sleep(channel);
-            sleep_mutex(addr_of_mut!(console.read_index).cast(), &mut console);
-        }
 
-        c = *console.read_byte();
-        console.read_index += 1;
+            c = *console.read_byte();
+            console.read_index += 1;
 
-        // ctrl-D or EOF
-        if c == ctrl_x(b'D') {
-            if n < target {
-                // Save ctrl-D for next time, to make
-                // sure caller gets a 0-byte result.
-                console.read_index -= 1;
+            // ctrl-D or EOF
+            if c == ctrl_x(b'D') {
+                if n < target {
+                    // Save ctrl-D for next time, to make
+                    // sure caller gets a 0-byte result.
+                    console.read_index -= 1;
+                }
+                break;
+            }
+
+            // Copy the input byte to the user-space buffer.
+            cbuf = c;
+            if either_copyout(user_dst, dst, addr_of_mut!(cbuf).cast(), 1) == -1 {
+                break;
+            }
+
+            dst += 1;
+            n -= 1;
+
+            if c == b'\n' {
+                // A whole line has arrived,
+                // return to the user-level read().
+                break;
             }
-            break;
         }
 
-        // Copy the input byte to the user-space buffer.
-        cbuf = c;
-        if either_copyout(user_dst, dst, addr_of_mut!(cbuf).cast(), 1) == -1 {
-            break;
-        }
+        // cons.lock.unlock();
 
-        dst += 1;
-        n -= 1;
-
-        if c == b'\n' {
-            // A whole line has arrived,
-            // return to the user-level read().
-            break;
-        }
+        target - n
     }
-
-    // cons.lock.unlock();
-
-    target - n
 }
 
 pub unsafe fn consoleinit() {
@@ -163,8 +165,8 @@ pub unsafe fn consoleinit() {
 
     // Connect read and write syscalls
     // to consoleread and consolewrite.
-    devsw[CONSOLE].read = consoleread as usize as *const i32;
-    devsw[CONSOLE].write = consolewrite as usize as *const i32;
+    devsw[CONSOLE].read = Some(consoleread);
+    devsw[CONSOLE].write = Some(consolewrite);
 }
 
 /// The console input interrupt handler.

kernel/rustkernel/src/fs/file.rs

@@ -1,12 +1,312 @@
+//! Support functions for system calls that involve file descriptors.
+
+use crate::{
+    fs::{log, stat::Stat},
+    io::pipe::{self, Pipe},
+    mem::virtual_memory::copyout,
+    proc::myproc,
+    sync::{sleeplock::Sleeplock, spinlock::Spinlock},
+};
+use core::{
+    ffi::CStr,
+    ptr::{addr_of_mut, null_mut},
+};
+
 #[repr(C)]
-pub struct Devsw {
-    pub read: *const i32,
-    pub write: *const i32,
+#[derive(Copy, Clone, PartialEq, Default)]
+pub enum FileType {
+    #[default]
+    None,
+    Pipe,
+    Inode,
+    Device,
 }
 
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct File {
+    kind: FileType,
+    /// Reference count.
+    references: i32,
+    readable: u8,
+    writable: u8,
+    /// FileType::Pipe
+    pipe: *mut Pipe,
+    /// FileType::Inode and FileType::Device
+    ip: *mut Inode,
+    /// FileType::Inode
+    off: u32,
+    /// FileType::Device
+    major: i16,
+}
+impl File {
+    pub const unsafe fn uninitialized() -> File {
+        File {
+            kind: FileType::None,
+            references: 0,
+            readable: 0,
+            writable: 0,
+            pipe: null_mut(),
+            ip: null_mut(),
+            off: 0,
+            major: 0,
+        }
+    }
+}
+
+#[repr(C)]
+pub struct Inode {
+    /// Device number.
+    device: u32,
+    /// Inode number.
+    inum: u32,
+    /// Reference count.
+    references: i32,
+
+    lock: Sleeplock,
+    /// Inode has been read from disk?
+    valid: i32,
+
+    // Copy of DiskInode
+    kind: i16,
+    major: i16,
+    minor: i16,
+    num_links: i16,
+    size: u32,
+    addresses: [u32; crate::fs::NDIRECT + 1],
+}
+
+/// Map major device number to device functions.
+#[repr(C)]
+#[derive(Copy, Clone, Default)]
+pub struct Devsw {
+    pub read: Option<fn(i32, u64, i32) -> i32>,
+    pub write: Option<fn(i32, u64, i32) -> i32>,
+}
+impl Devsw {
+    pub const fn new() -> Devsw {
+        Devsw {
+            read: None,
+            write: None,
+        }
+    }
+}
+
+#[repr(C)]
+pub struct FileTable {
+    lock: Spinlock,
+    files: [File; crate::NFILE],
+}
+
+#[no_mangle]
+pub static mut devsw: [Devsw; crate::NDEV] = [Devsw::new(); crate::NDEV];
+#[no_mangle]
+pub static mut ftable: FileTable = FileTable {
+    lock: unsafe { Spinlock::uninitialized() },
+    files: unsafe { [File::uninitialized(); crate::NFILE] },
+};
+pub const CONSOLE: usize = 1;
+
 extern "C" {
-    pub static mut devsw: [Devsw; crate::NDEV];
-    pub fn fileinit();
+    // pub fn fileinit();
+    // pub fn filealloc() -> *mut File;
+    // pub fn filedup(file: *mut File) -> *mut File;
+    // pub fn fileclose(file: *mut File);
+    // pub fn filestat(file: *mut File, addr: u64) -> i32;
+    // pub fn fileread(file: *mut File, addr: u64, n: i32) -> i32;
+    // pub fn filewrite(file: *mut File, addr: u64, n: i32) -> i32;
 }
 
-pub const CONSOLE: usize = 1;
+pub unsafe fn fileinit() {
+    ftable.lock = Spinlock::new(
+        CStr::from_bytes_with_nul(b"ftable\0")
+            .unwrap()
+            .as_ptr()
+            .cast_mut(),
+    );
+}
+
+/// Allocate a file structure.
+#[no_mangle]
+pub unsafe extern "C" fn filealloc() -> *mut File {
+    let _guard = ftable.lock.lock();
+
+    for file in &mut ftable.files {
+        if file.references == 0 {
+            file.references = 1;
+            return addr_of_mut!(*file);
+        }
+    }
+
+    null_mut()
+}
+
+/// Increment reference count for file `file`.
+#[no_mangle]
+pub unsafe extern "C" fn filedup(file: *mut File) -> *mut File {
+    let _guard = ftable.lock.lock();
+
+    if (*file).references < 1 {
+        panic!("filedup");
+    } else {
+        (*file).references += 1;
+    }
+
+    file
+}
+
+/// Close file `file`.
+///
+/// Decrement reference count, and close when reaching 0.
+#[no_mangle]
+pub unsafe extern "C" fn fileclose(file: *mut File) {
+    let guard = ftable.lock.lock();
+
+    if (*file).references < 1 {
+        panic!("fileclose");
+    }
+
+    (*file).references -= 1;
+
+    if (*file).references == 0 {
+        let f = *file;
+        (*file).references = 0;
+        (*file).kind = FileType::None;
+        core::mem::drop(guard);
+
+        match f.kind {
+            FileType::Pipe => pipe::pipeclose(f.pipe, f.writable as i32),
+            FileType::Inode | FileType::Device => {
+                log::begin_op();
+                super::iput(f.ip);
+                log::end_op();
+            }
+            FileType::None => {}
+        }
+    }
+}
+
+/// Get metadata about file `file`.
+///
+/// `addr` is a user virtual address, pointing to a Stat.
+#[no_mangle]
+pub unsafe extern "C" fn filestat(file: *mut File, addr: u64) -> i32 {
+    let p = myproc();
+    let mut stat = Stat::default();
+
+    if (*file).kind == FileType::Inode || (*file).kind == FileType::Device {
+        super::ilock((*file).ip);
+        super::stati((*file).ip, addr_of_mut!(stat));
+        super::iunlock((*file).ip);
+
+        if copyout(
+            (*p).pagetable,
+            addr,
+            addr_of_mut!(stat).cast(),
+            core::mem::size_of::<Stat>() as u64,
+        ) < 0
+        {
+            return -1;
+        } else {
+            return 0;
+        }
+    }
+
+    -1
+}
+
+/// Read from file `file`.
+///
+/// `addr` is a user virtual address.
+#[no_mangle]
+pub unsafe extern "C" fn fileread(file: *mut File, addr: u64, n: i32) -> i32 {
+    if (*file).readable == 0 {
+        return -1;
+    }
+
+    match (*file).kind {
+        FileType::Pipe => pipe::piperead((*file).pipe, addr, n),
+        FileType::Device => {
+            if (*file).major < 0 || (*file).major >= crate::NDEV as i16 {
+                return -1;
+            }
+            let Some(read) = devsw[(*file).major as usize].read else {
+                return -1;
+            };
+
+            read(1, addr, n)
+        }
+        FileType::Inode => {
+            super::ilock((*file).ip);
+            let r = super::readi((*file).ip, 1, addr, (*file).off, n as u32);
+            if r > 0 {
+                (*file).off += r as u32;
+            }
+            super::iunlock((*file).ip);
+            r
+        }
+        _ => panic!("fileread"),
+    }
+}
+
+/// Write to file `file`.
+///
+/// `addr` is as user virtual address.
+#[no_mangle]
+pub unsafe extern "C" fn filewrite(file: *mut File, addr: u64, n: i32) -> i32 {
+    if (*file).writable == 0 {
+        return -1;
+    }
+
+    match (*file).kind {
+        FileType::Pipe => pipe::pipewrite((*file).pipe, addr, n),
+        FileType::Device => {
+            if (*file).major < 0 || (*file).major >= crate::NDEV as i16 {
+                return -1;
+            }
+            let Some(write) = devsw[(*file).major as usize].write else {
+                return -1;
+            };
+
+            write(1, addr, n)
+        }
+        FileType::Inode => {
+            // Write a few blocks at a time to avoid exceeding
+            // the maximum log transaction size, including
+            // inode, indirect block, allocation blocks,
+            // and 2 blocks of slop for non-aligned writes.
+            // This really belongs lower down, since writei()
+            // might be writing a device like the console.
+            let max = ((crate::MAXOPBLOCKS - 1 - 1 - 2) / 2) * super::BSIZE as usize;
+            let mut i = 0;
+            while i < n {
+                let mut n1 = n - i;
+                if n1 > max as i32 {
+                    n1 = max as i32;
+                }
+
+                log::begin_op();
+                super::ilock((*file).ip);
+                let r = super::writei((*file).ip, 1, addr + i as u64, (*file).off, n1 as u32);
+                if r > 0 {
+                    (*file).off += r as u32;
+                }
+                super::iunlock((*file).ip);
+                log::end_op();
+
+                if r != n1 {
+                    // Error from writei.
+                    break;
+                } else {
+                    i += r;
+                }
+            }
+            if i == n {
+                n
+            } else {
+                -1
+            }
+        }
+        _ => panic!("filewrite"),
+    }
+}

kernel/rustkernel/src/fs/log.rs

@@ -0,0 +1,27 @@
+use crate::{fs::Superblock, io::buf::Buffer, sync::spinlock::Spinlock};
+
+#[repr(C)]
+pub struct LogHeader {
+    pub n: i32,
+    pub blocks: [i32; crate::LOGSIZE],
+}
+#[repr(C)]
+pub struct Log {
+    lock: Spinlock,
+    start: i32,
+    size: i32,
+    /// How many FS syscalls are executing.
+    outstanding: i32,
+    /// In commit(), please wait.
+    committing: i32,
+    dev: i32,
+    header: LogHeader,
+}
+
+extern "C" {
+    pub static mut log: Log;
+    pub fn initlog(dev: i32, superblock: *mut Superblock);
+    pub fn begin_op();
+    pub fn end_op();
+    pub fn log_write(buffer: *mut Buffer);
+}

kernel/rustkernel/src/fs/mod.rs

@@ -1,10 +1,14 @@
-//! On-disk file system forma.
+//! On-disk file system format.
 //! Both the kernel and user programs use this header file.
 
 pub mod file;
+pub mod log;
 pub mod ramdisk;
+pub mod stat;
 pub mod virtio_disk;
 
+use crate::fs::file::Inode;
+
 // Root inode
 pub const ROOTINO: u64 = 1;
 /// Block size.
@@ -36,9 +40,9 @@ pub struct Superblock {
 }
 
 pub const FSMAGIC: u32 = 0x10203040;
-pub const NDIRECT: u32 = 12;
-pub const NINDIRECT: u32 = BSIZE / core::mem::size_of::<u32>() as u32;
-pub const MAXFILE: u32 = NDIRECT + NINDIRECT;
+pub const NDIRECT: usize = 12;
+pub const NINDIRECT: usize = BSIZE as usize / core::mem::size_of::<u32>();
+pub const MAXFILE: usize = NDIRECT + NINDIRECT;
 
 // On-disk inode structure;
 #[repr(C)]
@@ -54,7 +58,7 @@ pub struct DiskInode {
     /// Size of file (bytes).
     pub size: u32,
     /// Data block addresses.
-    pub addrs: [u32; NDIRECT as usize + 1],
+    pub addrs: [u32; NDIRECT + 1],
 }
 
 /// Inodes per block.
@@ -83,5 +87,18 @@ pub struct DirectoryEntry {
 }
 
 extern "C" {
+    pub fn fsinit(dev: i32);
     pub fn iinit();
+    pub fn ialloc(dev: u32, kind: i16) -> *mut DiskInode;
+    pub fn iupdate(ip: *mut DiskInode);
+    pub fn idup(ip: *mut DiskInode) -> *mut DiskInode;
+    pub fn ilock(ip: *mut Inode);
+    pub fn iunlock(ip: *mut Inode);
+    pub fn iput(ip: *mut Inode);
+    pub fn iunlockput(ip: *mut DiskInode);
+    pub fn itrunc(ip: *mut DiskInode);
+    pub fn stati(ip: *mut Inode, st: *mut stat::Stat);
+    pub fn readi(ip: *mut Inode, user_dst: i32, dst: u64, off: u32, n: u32) -> i32;
+    pub fn writei(ip: *mut Inode, user_src: i32, src: u64, off: u32, n: u32) -> i32;
+    // pub fn namecmp()
 }

kernel/rustkernel/src/fs/stat.rs

@@ -0,0 +1,21 @@
+#[repr(C)]
+pub enum StatType {
+    Directory = 1,
+    File,
+    Device,
+}
+
+#[repr(C)]
+#[derive(Default)]
+pub struct Stat {
+    /// FS's disk device.
+    pub device: i32,
+    /// Inode number.
+    pub inode: u32,
+    /// Type of file.
+    pub kind: i16,
+    /// Number of links to file.
+    pub num_links: i16,
+    /// Size of file in bytes.
+    pub size: u64,
+}

kernel/rustkernel/src/io/pipe.rs

@@ -1,4 +1,4 @@
-use crate::sync::spinlock::Spinlock;
+use crate::{fs::file::File, sync::spinlock::Spinlock};
 use core::ffi::c_char;
 
 pub const PIPESIZE: usize = 512usize;
@@ -16,3 +16,10 @@ pub struct Pipe {
     /// Write fd is still open.
     writeopen: i32,
 }
+
+extern "C" {
+    pub fn pipealloc(a: *mut *mut File, b: *mut *mut File) -> i32;
+    pub fn pipeclose(pipe: *mut Pipe, writable: i32);
+    pub fn pipewrite(pipe: *mut Pipe, addr: u64, n: i32) -> i32;
+    pub fn piperead(pipe: *mut Pipe, addr: u64, n: i32) -> i32;
+}