# HG changeset patch
# User menikon
# Date 1581163519 -32400
# Node ID 40726bcd527241a252d5abdcba81246214820567
# Parent  dca5e4f9fceb07da5e9b75a2687e6c8b5637d404
add src

diff -r dca5e4f9fceb -r 40726bcd5272 final_main/appendix.tex
--- a/final_main/appendix.tex	Sat Feb 08 19:00:35 2020 +0900
+++ b/final_main/appendix.tex	Sat Feb 08 21:05:19 2020 +0900
@@ -0,0 +1,6 @@
+\chapter*{付録}
+
+\lstinputlisting[label=fs.ds,  caption=FileSystem の Interface]{src/fs.dg}
+\lstinputlisting[label=fs_impl.h,  caption=]{src/fs_impl.h}
+\lstinputlisting[label=fs_impl.cbc,  caption=FileSystem の 実装]{src/fs_impl.cbc}
+\lstinputlisting[label=fs_impl_private.cbc,  caption=FileSystem の 実装]{src/fs_impl_private.cbc}
\ No newline at end of file
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/chapter2.tex
--- a/final_main/chapter2.tex	Sat Feb 08 19:00:35 2020 +0900
+++ b/final_main/chapter2.tex	Sat Feb 08 21:05:19 2020 +0900
@@ -15,6 +15,7 @@
 本研究ではこのプログラミング言語を用いて xv6 の Filesystemを書き換える.
 \section{CodeGear}
 CodeGear は CbCにおける基本的な処理単位である. 以下のソースコード\ref{cbcexample}は CodeGear の継続の例である.
+\newpage
 \lstinputlisting[label=cbcexample,  caption=CodeGearの継続の例]{src/cbc_example.cbc}
 CodeGear は\_\_code CodeGear名 (引数) の形で記述される.
 CodeGear は返り値を持たない為, 関数内で処理が終了すると呼び出し 元の関数に戻ることがなく別の CodeGear へ遷移する. 
@@ -30,7 +31,7 @@
 
 また CbC における CodeGear 間の継続にはスタックが使用されず, 呼び出し元の環境などを持たない為軽量継続と呼ぶ.
 この CbC における CodeGear 間の継続にスタックが使用されない性質は信頼性の高い OS の開発に適している.
-
+\newpage
 \section{DataGear}
 DataGear は CbCにおけるデータの基本的な単位である. CodeGear は  Input DataGear, Output DataGear を引数に持ち,図\ref{fig:DataGear}で示したように遷移する際に任意のInput DataGearを参照し, Output DataGearを書き出す.
 
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/chapter4.tex
--- a/final_main/chapter4.tex	Sat Feb 08 19:00:35 2020 +0900
+++ b/final_main/chapter4.tex	Sat Feb 08 21:05:19 2020 +0900
@@ -10,14 +10,22 @@
 %processについて(軽く)
 
 \section{xv6 のFileSystem構造}
+\begin{figure}[ht]
+     \begin{center}
+     \includegraphics[width=50mm]{fig/FileSystemLayout.pdf}
+     \end{center}
+     \caption{xv6 の FileSystem }
+    \label{fig:xv6filesystem}
+\end{figure}
+
+\newpage
 xv6 の FileSystem の構造を以下の図\ref{fig:filesystem}に示す.
 
-\vspace{10mm}
 \begin{figure}[ht]
      \begin{center}
      \includegraphics[width=150mm]{fig/xv6filesystemlayout.pdf}
      \end{center}
-     \caption{xv6 の FileSystem Layout}
+     \caption{xv6 の FileSystem }
     \label{fig:filesystem}
 \end{figure}
 
@@ -25,17 +33,10 @@
   \item boot sector
   \item super block
   \item inode
-  \item 
+  \item block bitmap
+  \item data blocks
+  \item log
 \end{itemize}
 
 \section{FilleSystem の API} %関数や構造体などを解説しそのまま利用されているところをかく
 
-
-
-
-
-\section{block bitmap}
-
-\section{data blocks}
-
-\section{log}
\ No newline at end of file
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/fig/DataGear.graffle
Binary file final_main/fig/DataGear.graffle has changed
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/fig/DataGear.pdf
Binary file final_main/fig/DataGear.pdf has changed
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/fig/FileSystemLayout.graffle
Binary file final_main/fig/FileSystemLayout.graffle has changed
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/fig/FileSystemLayout.pdf
Binary file final_main/fig/FileSystemLayout.pdf has changed
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/main.out
--- a/final_main/main.out	Sat Feb 08 19:00:35 2020 +0900
+++ b/final_main/main.out	Sat Feb 08 21:05:19 2020 +0900
@@ -11,11 +11,8 @@
 \BOOKMARK [1][-]{section.4.1}{4.1 xv6 とは}{chapter.4}% 11
 \BOOKMARK [1][-]{section.4.2}{4.2 xv6 のFileSystem構造}{chapter.4}% 12
 \BOOKMARK [1][-]{section.4.3}{4.3 FilleSystem の API}{chapter.4}% 13
-\BOOKMARK [1][-]{section.4.4}{4.4 block bitmap}{chapter.4}% 14
-\BOOKMARK [1][-]{section.4.5}{4.5 data blocks}{chapter.4}% 15
-\BOOKMARK [1][-]{section.4.6}{4.6 log}{chapter.4}% 16
-\BOOKMARK [0][-]{chapter.5}{第5章 CbCによるFileSystemの書き換え}{}% 17
-\BOOKMARK [1][-]{section.5.1}{5.1 書き換え方針}{chapter.5}% 18
-\BOOKMARK [1][-]{section.5.2}{5.2 FileSystemのInterface}{chapter.5}% 19
-\BOOKMARK [1][-]{section.5.3}{5.3 CbC による FileSystem の書き換え}{chapter.5}% 20
-\BOOKMARK [0][-]{chapter.6}{第6章 まとめと今後の課題}{}% 21
+\BOOKMARK [0][-]{chapter.5}{第5章 CbCによるFileSystemの書き換え}{}% 14
+\BOOKMARK [1][-]{section.5.1}{5.1 書き換え方針}{chapter.5}% 15
+\BOOKMARK [1][-]{section.5.2}{5.2 FileSystemのInterface}{chapter.5}% 16
+\BOOKMARK [1][-]{section.5.3}{5.3 CbC による FileSystem の書き換え}{chapter.5}% 17
+\BOOKMARK [0][-]{chapter.6}{第6章 まとめと今後の課題}{}% 18
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/main.pdf
Binary file final_main/main.pdf has changed
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/main.tex
--- a/final_main/main.tex	Sat Feb 08 19:00:35 2020 +0900
+++ b/final_main/main.tex	Sat Feb 08 21:05:19 2020 +0900
@@ -105,6 +105,6 @@
 \input{thanks.tex}
 
 % 付録
-%\input{appendix.tex}
+\input{appendix.tex}
 
 \end{document}
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/src/fs_impl.cbc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/final_main/src/fs_impl.cbc	Sat Feb 08 21:05:19 2020 +0900
@@ -0,0 +1,381 @@
+#include "types.h"
+#include "defs.h"
+#include "param.h"
+#include "stat.h"
+#include "mmu.h"
+#include "proc.h"
+#include "spinlock.h"
+#include "buf.h"
+#include "fs.h"
+#include "file.h"
+#interface "Err.h"
+#interface "fs.dg"
+
+// ----
+// typedef struct fs_impl<Impl, Isa> impl fs{
+//     union Data* fs_impl;
+// 
+// 
+// 
+// 
+// } fs_impl;
+// ----
+
+fs* createfs_impl(struct Context* cbc_context) {
+    struct fs* fs  = new fs();
+    struct fs_impl* fs_impl = new fs_impl();
+    fs->fs = (union Data*)fs_impl;
+    fs_impl->fs_impl = NULL;
+    fs_impl->sb = NULL;
+    fs_impl->ret  = 0;
+    fs_impl->dev  = 0;
+    fs_impl->type  = 0;
+    fs_impl->bp = NULL;
+    fs_impl->dip = NULL;
+    fs_impl->inum  = 0;
+    fs_impl->dp = NULL;
+    fs_impl->name = NULL;
+    fs_impl->off  = 0;
+    fs_impl->poff = NULL;
+    fs_impl->de = NULL;
+    fs_impl->tot  = 0;
+    fs_impl->m  = 0;
+    fs_impl->dst = NULL;
+    fs_impl->n  = 0;
+    fs_impl->src = NULL;
+    fs_impl->allocinode = C_allocinode;
+    fs_impl->allocinode_loop = C_allocinode_loop;
+    fs_impl->allocinode_loopcheck = C_allocinode_loopcheck;
+    fs_impl->allocinode_noloop = C_allocinode_noloop;
+    fs_impl->lockinode1 = C_lockinode1;
+    fs_impl->lockinode2 = C_lockinode2;
+    fs_impl->lockinode_sleepcheck = C_lockinode_sleepcheck;
+    fs_impl->iput_check = C_iput_check;
+    fs_impl->iput_inode_nolink = C_iput_inode_nolink;
+    fs_impl->readi_check_diskinode = C_readi_check_diskinode;
+    fs_impl->readi_loopcheck = C_readi_loopcheck;
+    fs_impl->readi_loop = C_readi_loop;
+    fs_impl->readi_noloop = C_readi_noloop;
+    fs_impl->writei_check_diskinode = C_writei_check_diskinode;
+    fs_impl->writei_loopcheck = C_writei_loopcheck;
+    fs_impl->writei_loop = C_writei_loop;
+    fs_impl->writei_noloop = C_writei_noloop;
+    fs_impl->dirlookup_loopcheck = C_dirlookup_loopcheck;
+    fs_impl->dirlookup_loop = C_dirlookup_loop;
+    fs_impl->dirlookup_noloop = C_dirlookup_noloop;
+    fs_impl->dirlink_namecheck = C_dirlink_namecheck;
+    fs_impl->dirlink_loopcheck = C_dirlink_loopcheck;
+    fs_impl->dirlink_loop = C_dirlink_loop;
+    fs_impl->dirlink_noloop = C_dirlink_noloop;
+    fs->readsb = C_readsbfs_impl;
+    fs->iinit = C_iinitfs_impl;
+    fs->ialloc = C_iallocfs_impl;
+    fs->iupdate = C_iupdatefs_impl;
+    fs->idup = C_idupfs_impl;
+    fs->ilock = C_ilockfs_impl;
+    fs->iunlock = C_iunlockfs_impl;
+    fs->iput = C_iputfs_impl;
+    fs->iunlockput = C_iunlockputfs_impl;
+    fs->stati = C_statifs_impl;
+    fs->readi = C_readifs_impl;
+    fs->writei = C_writeifs_impl;
+    fs->namecmp = C_namecmpfs_impl;
+    fs->dirlookup = C_dirlookupfs_impl;
+    fs->dirlink = C_dirlinkfs_impl;
+    fs->namei = C_nameifs_impl;
+    fs->nameiparent = C_nameiparentfs_impl;
+    return fs;
+}
+
+typedef struct superblock superblock;
+__code readsbfs_impl(struct fs_impl* fs, uint dev, struct superblock* sb, __code next(...)) { //:skip
+
+    struct buf* bp;
+
+    bp = bread(dev, 1);
+    memmove(sb, bp->data, sizeof(*sb));
+    brelse(bp);
+
+    goto next(...);
+}
+
+struct {
+    struct spinlock lock;
+    struct inode inode[NINODE];
+} icache;
+
+__code iinitfs_impl(struct fs_impl* fs, __code next(...)) {
+
+     initlock(&icache.lock, "icache");
+
+    goto next(...);
+}
+
+__code iallocfs_impl(struct fs_impl* fs, uint dev, short type, __code next(...)) {
+    goto allocinode(fs, dev, sb, next(...));
+}
+
+__code iupdatefs_impl(struct fs_impl* fs, struct inode* ip, __code next(...)) {
+
+    struct buf *bp;
+    struct dinode *dip;
+
+    bp = bread(ip->dev, IBLOCK(ip->inum));
+
+    dip = (struct dinode*) bp->data + ip->inum % IPB;
+    dip->type = ip->type;
+    dip->major = ip->major;
+    dip->minor = ip->minor;
+    dip->nlink = ip->nlink;
+    dip->size = ip->size;
+
+    memmove(dip->addrs, ip->addrs, sizeof(ip->addrs));
+    log_write(bp);
+    brelse(bp);
+
+
+    goto next(...);
+}
+
+__code idupfs_impl(struct fs_impl* fs, struct inode* ip, __code next(...)) {
+
+    acquire(&icache.lock);
+    ip->ref++;
+    release(&icache.lock);
+    
+    goto next(ip, ...);
+
+}
+
+__code ilockfs_impl(struct fs_impl* fs, struct inode* ip, __code next(...)) {
+
+    goto lockinode1(fs, ip, bp, dip, next(...));
+}
+
+__code iunlockfs_impl(struct fs_impl* fs, struct inode* ip, __code next(...)) {
+    
+    if (ip == 0 || !(ip->flags & I_BUSY) || ip->ref < 1) {
+       char* msg = "iunlock";
+       struct Err* err = createKernelError(&proc->cbc_context);
+       Gearef(cbc_context, Err)->msg = msg;
+       goto meta(cbc_context, err->panic);
+    }
+
+    acquire(&icache.lock);
+    ip->flags &= ~I_BUSY;
+    wakeup(ip);
+    release(&icache.lock);
+
+    goto next(...);
+}
+
+__code iputfs_impl(struct fs_impl* fs, struct inode* ip, __code next(...)) {
+    if (next == C_iputfs_impl) {
+        next = fs->next2;
+    }
+    goto iput_check(fs, ip, next(...));   
+
+}
+
+__code iunlockputfs_impl(struct fs_impl* fs, struct inode* ip, __code next(...)) {    
+    fs->next2 = next; 
+    goto iunlockfs_impl(ip, fs->iput, ...);
+}
+
+typedef struct stat stat;
+__code statifs_impl(struct fs_impl* fs , struct inode* ip, struct stat* st, __code next(...)) { //:skip
+    st->dev = ip->dev;
+    st->ino = ip->inum;
+    st->type = ip->type;
+    st->nlink = ip->nlink;
+    st->size = ip->size;
+    goto next(...);
+}
+
+__code readifs_impl(struct fs_impl* fs, struct inode* ip, char* dst, uint off, uint tot, uint n, __code next(int ret, ...)) {
+    if (ip->type == T_DEV) {
+        goto readi_check_diskinode(fs, ip, dst, n, next(...));
+    }
+
+    if (off > ip->size || off + n < off) {
+        ret = -1;
+        goto next(ret, ...);
+    }
+
+    if (off + n > ip->size) {
+        n = ip->size - off;
+    }
+    Gearef(cbc_context, fs)->tot = 0;
+    goto readi_loopcheck(fs, tot, m, dst, off, n, next(...));
+}
+
+__code writeifs_impl(struct fs_impl* fs, struct inode* ip, char* src, uint off, uint tot, uint n, __code next(int ret, ...)) {
+    if (ip->type == T_DEV) { 
+        goto writei_check_diskinode(fs, ip, src, n, next(...));
+    }
+    
+    if (off > ip->size || off + n < off) {
+        ret = -1;
+        goto next(ret, ...);
+    }
+    
+    if (off + n > MAXFILE * BSIZE) {
+        ret = -1;
+        goto next(ret, ...);
+    }
+    Gearef(cbc_context, fs)->tot = 0;
+    goto writei_loopcheck(fs, tot, m, src, off, n, next(...));
+}
+
+
+__code namecmpfs_impl(struct fs_impl* fs, const char* s, const char* t, __code next(int strncmp_val, ...)) {
+    strncmp_val = strncmp(s, t, DIRSIZ);
+    goto next(strncmp_val, ...);
+}
+
+__code dirlookupfs_impl(struct fs_impl* fs, struct inode* dp, char* name, uint off, uint* poff, dirent* de,  __code next(...)) { //:skip
+    if (dp->type != T_DIR) { 
+       char* msg = "dirlookup not DIR";
+       struct Err* err = createKernelError(&proc->cbc_context);
+       Gearef(cbc_context, Err)->msg = msg;
+       goto meta(cbc_context, err->panic);
+    }
+    Gearef(cbc_context, fs)->off = 0;
+    goto dirlookup_loopcheck(fs, dp, name, off, poff, de, next(...));
+}
+
+__code dirlinkfs_impl(struct fs_impl* fs, struct inode* ip, struct dirent* de, struct inode* dp, char* name, uint off, uint inum, __code next(...)) { //:skip
+    // Check that name is not present.
+    if ((ip = dirlookup(dp, name, 0)) != 0) {
+        goto dirlink_namecheck(fs, ip, next(...));
+    }
+    Gearef(cbc_context, fs)->off = 0;
+    goto dirlink_loopcheck(fs, de, dp, off, next(...));
+}
+
+static struct inode* iget (uint dev, uint inum)
+{
+    struct inode *ip, *empty;
+
+    acquire(&icache.lock);
+
+    // Is the inode already cached?
+    empty = 0;
+
+    for (ip = &icache.inode[0]; ip < &icache.inode[NINODE]; ip++) {
+        if (ip->ref > 0 && ip->dev == dev && ip->inum == inum) {
+            ip->ref++;
+            release(&icache.lock);
+            return ip;
+        }
+
+        if (empty == 0 && ip->ref == 0) {   // Remember empty slot.
+            empty = ip;
+        }
+    }
+
+    // Recycle an inode cache entry.
+    if (empty == 0) {
+        panic("iget: no inodes");
+    }
+
+    ip = empty;
+    ip->dev = dev;
+    ip->inum = inum;
+    ip->ref = 1;
+    ip->flags = 0;
+    release(&icache.lock);
+
+    return ip;
+}
+
+static char* skipelem (char *path, char *name)
+{
+    char *s;
+    int len;
+
+    while (*path == '/') {
+        path++;
+    }
+
+    if (*path == 0) {
+        return 0;
+    }
+
+    s = path;
+
+    while (*path != '/' && *path != 0) {
+        path++;
+    }
+
+    len = path - s;
+
+    if (len >= DIRSIZ) {
+        memmove(name, s, DIRSIZ);
+    } else {
+        memmove(name, s, len);
+        name[len] = 0;
+    }
+
+    while (*path == '/') {
+        path++;
+    }
+
+    return path;
+}
+
+
+static struct inode* namex (char *path, int nameiparent, char *name)
+{
+    struct inode *ip, *next;
+
+    if (*path == '/') {
+        ip = iget(ROOTDEV, ROOTINO);
+    } else {
+        ip = idup(proc->cwd);
+    }
+
+    while ((path = skipelem(path, name)) != 0) {
+        ilock(ip);
+
+        if (ip->type != T_DIR) {
+            iunlockput(ip);
+            return 0;
+        }
+
+        if (nameiparent && *path == '\0') {
+            // Stop one level early.
+            iunlock(ip);
+            return ip;
+        }
+
+        if ((next = dirlookup(ip, name, 0)) == 0) {
+            iunlockput(ip);
+            return 0;
+        }
+
+        iunlockput(ip);
+        ip = next;
+    }
+
+    if (nameiparent) {
+        iput(ip);
+        return 0;
+    }
+
+    return ip;
+}
+
+__code nameifs_impl(struct fs_impl* fs, char* path, __code next(int namex_val, ...)) {
+    char name[DIRSIZ];
+    namex_val = namex(path, 0, name);
+    goto next(namex_val, ...);
+}
+
+__code nameiparentfs_impl(struct fs_impl* fs, char* path, char* name, __code next(int namex_val, ...)) {
+
+    namex_val = namex(path, 1, name);
+    goto next(namex_val, ...);
+
+}
+
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/src/fs_impl.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/final_main/src/fs_impl.h	Sat Feb 08 21:05:19 2020 +0900
@@ -0,0 +1,47 @@
+typedef struct fs_impl<Type, Isa> impl fs{
+    union Data* fs_impl;
+    struct superblock* sb;
+    int ret;
+    uint dev;
+    short type;
+    struct buf* bp;
+    struct dinode* dip;
+    uint inum;
+    struct inode* dp;
+    char* name;
+    uint off;
+    uint* poff;
+    dirent* de;
+    uint tot;
+    uint m;
+    char* dst;
+    uint n;
+    char* src;
+
+    __code allocinode(Type* fs_impl, uint dev, struct superblock* sb, __code next(...));
+    __code allocinode_loop(Type* fs_impl, uint inum, uint dev, short type, struct superblock* sb, struct buf* bp, struct dinode* dip, __code next(...));
+    __code allocinode_loopcheck(Type* fs_impl, uint inum, uint dev, struct superblock* sb, struct buf* bp, struct dinode* dip, __code next(...));
+    __code allocinode_noloop(Type* fs_impl, uint inum, uint dev, short type, struct superblock* sb, struct buf* bp, struct dinode* dip, __code next(int ret, ...));
+    __code lockinode1(Type* fs_impl, struct inode *ip, struct buf *bp, struct dinode *dip, __code next(...));
+    __code lockinode2(Type* fs_impl, struct inode* ip, struct buf* bp, struct dinode* dip, __code next(...));
+    __code lockinode_sleepcheck(Type* fs_impl, struct inode* ip, __code next(...));
+    __code iput_check(Type* fs_impl, struct inode* ip, __code next(...));
+    __code iput_inode_nolink(Type* fs_impl, struct inode* ip, __code next(...));
+    __code readi_check_diskinode(Type* fs_impl,struct inode* ip, char* dst, uint n, next(int ret, ...));
+    __code readi_loopcheck(Type* fs_impl, uint tot, uint m, char* dst, uint off, uint n, __code next(...));
+    __code readi_loop(Type* fs_impl, struct inode *ip, struct buf* bp, uint tot, uint m, char* dst, uint off, uint n, __code next(...));
+    __code readi_noloop(Type* fs_impl, uint n, __code next(int ret, ...));
+    __code writei_check_diskinode(Type* fs_impl,struct inode* ip, char* src, uint n, __code next(int ret, ...));
+    __code writei_loopcheck(Type* fs_impl, uint tot, uint m, char* src, uint off, uint n, __code next(...));
+    __code writei_loop(Type* fs_impl, struct inode* ip, struct buf* bp, uint tot, uint m, char* src, uint off, uint n, __code next(...));
+    __code writei_noloop(Type* fs_impl, struct inode* ip, uint n, uint off, __code next(int ret, ...));
+    __code dirlookup_loopcheck(Type* fs_impl, struct inode* dp, char* name, uint off, uint* poff, dirent* de, next(...));
+    __code dirlookup_loop(Type* fs_impl, struct inode* dp, char* name, uint off, uint inum, uint* poff, dirent* de, __code next(int ret, ...));
+    __code dirlookup_noloop(Type* fs_impl, __code next(int ret, ...));
+    __code dirlink_namecheck(Type* fs_impl, struct inode* ip, __code next(int ret, ...));
+    __code dirlink_loopcheck(Type* fs_impl, struct dirent* de, struct inode* dp, uint off, __code next(...));
+    __code dirlink_loop(Type* fs_impl, struct dirent* de, struct inode* dp, uint off, uint inum, __code next(...));
+    __code dirlink_noloop(Type* fs_impl, struct dirent* de, struct inode* dp, uint off, uint inum, char* name, __code next(int ret, ...));
+    __code next(...);
+    __code next2(...);
+} fs_impl;
diff -r dca5e4f9fceb -r 40726bcd5272 final_main/src/fs_impl_private.cbc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/final_main/src/fs_impl_private.cbc	Sat Feb 08 21:05:19 2020 +0900
@@ -0,0 +1,471 @@
+#include "types.h"
+#include "defs.h"
+#include "param.h"
+#include "stat.h"
+#include "mmu.h"
+#include "proc.h"
+#include "spinlock.h"
+#include "buf.h"
+#include "fs.h"
+#include "file.h"
+#interface "fs_impl.h"
+#interface "Err.h"
+#define min(a, b) ((a) < (b) ? (a) : (b))
+
+/*
+fs_impl* createfs_impl2();
+*/
+
+__code allocinode(struct fs_impl* fs_impl, uint dev, struct superblock* sb, __code next(...)){ //:skip
+
+    readsb(dev, sb);
+    Gearef(cbc_context, fs_impl)->inum = 1; 
+    goto allocinode_loopcheck(fs_impl, inum, dev, sb, bp, dip, next(...));
+
+}
+
+typedef struct buf buf;
+typedef struct dinode dinode;
+
+__code allocinode_loopcheck(struct fs_impl* fs_impl, uint inum, uint dev, struct superblock* sb, struct buf* bp, struct dinode* dip, __code next(...)){ //:skip
+    if( inum < sb->ninodes){
+        goto allocinode_loop(fs_impl, inum, dev, type, sb, bp, dip, next(...));
+    }
+    char* msg = "failed allocinode...";
+    struct Err* err = createKernelError(&proc->cbc_context);
+    Gearef(cbc_context, Err)->msg = msg;
+    goto meta(cbc_context, err->panic);
+
+}
+
+__code allocinode_loop(struct fs_impl* fs_impl, uint inum, uint dev, short type, struct superblock* sb, struct buf* bp, struct dinode* dip, __code next(...)){ //:skip
+    bp = bread(dev, IBLOCK(inum));
+    dip = (struct dinode*) bp->data + inum % IPB;
+    if(dip->type = 0){
+        goto allocinode_noloop(fs_impl, inum, dev, sb, bp, dip, next(...));
+    }
+    
+    brelse(bp);    
+    inum++;
+    goto allocinode_loopcheck(fs_impl, inum, dev, type, sb, bp, dip, next(...));
+}
+
+struct {
+    struct spinlock lock;
+    struct inode inode[NINODE];
+} icache;
+
+static struct inode* iget (uint dev, uint inum)
+{
+    struct inode *ip, *empty;
+
+    acquire(&icache.lock);
+
+    // Is the inode already cached?
+    empty = 0;
+
+    for (ip = &icache.inode[0]; ip < &icache.inode[NINODE]; ip++) {
+        if (ip->ref > 0 && ip->dev == dev && ip->inum == inum) {
+            ip->ref++;
+            release(&icache.lock);
+            return ip;
+        }
+
+        if (empty == 0 && ip->ref == 0) {   // Remember empty slot.
+            empty = ip;
+        }
+    }
+
+    // Recycle an inode cache entry.
+    if (empty == 0) {
+        panic("iget: no inodes");
+    }
+
+    ip = empty;
+    ip->dev = dev;
+    ip->inum = inum;
+    ip->ref = 1;
+    ip->flags = 0;
+    release(&icache.lock);
+
+    return ip;
+}
+
+__code allocinode_noloop(struct fs_impl* fs_impl, uint inum, uint dev, short type, struct superblock* sb, struct buf* bp, struct dinode* dip, __code next(int ret, ...)){ //:skip
+
+    memset(dip, 0, sizeof(*dip));
+    dip->type = type;
+    log_write(bp);   
+    brelse(bp);
+    
+    ret = iget(dev, inum);
+    goto next(ret, ...);
+
+}
+
+__code lockinode1(struct fs_impl* fs_impl, struct inode* ip, struct buf* bp, struct dinode* dip, __code next(...)){ //:skip
+
+    if (ip == 0 || ip->ref < 1) {
+       char* msg = "ilock";
+       struct Err* err = createKernelError(&proc->cbc_context);
+       Gearef(cbc_context, Err)->msg = msg;
+       goto meta(cbc_context, err->panic);
+     }
+    acquire(&icache.lock);
+
+    goto lockinode_sleepcheck(fs_impl, ip, next(...));
+    
+}
+
+
+__code lockinode2(struct fs_impl* fs_impl, struct inode* ip, struct buf* bp, struct dinode* dip, __code next(...)){ //:skip
+
+    ip->flags |= I_BUSY;
+    release(&icache.lock);
+
+    if (!(ip->flags & I_VALID)) {
+        bp = bread(ip->dev, IBLOCK(ip->inum));
+
+        dip = (struct dinode*) bp->data + ip->inum % IPB;
+        ip->type = dip->type;
+        ip->major = dip->major;
+        ip->minor = dip->minor;
+        ip->nlink = dip->nlink;
+        ip->size = dip->size;
+
+        memmove(ip->addrs, dip->addrs, sizeof(ip->addrs));
+        brelse(bp);
+        ip->flags |= I_VALID;
+
+        if (ip->type == 0) {
+             char* msg = "ilock: no type";
+             struct Err* err = createKernelError(&proc->cbc_context);
+             Gearef(cbc_context, Err)->msg = msg;
+             goto meta(cbc_context, err->panic);
+        }
+    }
+    goto next(...);
+}
+__code lockinode_sleepcheck(struct fs_impl* fs_impl, struct inode* ip, __code next(...)){
+    if(ip->flags & I_BUSY){
+        sleep(ip, &icache.lock);
+        goto lockinode_sleepcheck(fs_impl, ip, next(...));
+    }
+    goto lockinode2(fs_impl, ip, bp, dip, next(...));
+}
+
+__code iput_check(struct fs_impl* fs_impl, struct inode* ip, __code next(...)){
+    acquire(&icache.lock);
+    if (ip->ref == 1 && (ip->flags & I_VALID) && ip->nlink == 0) { 
+        goto iput_inode_nolink(fs_impl, ip, next(...));
+    }
+    ip->ref--;
+    release(&icache.lock);
+    goto next(...);
+
+}
+
+static void bfree (int dev, uint b)
+{
+    struct buf *bp;
+    struct superblock sb;
+    int bi, m;
+
+    readsb(dev, &sb);
+    bp = bread(dev, BBLOCK(b, sb.ninodes));
+    bi = b % BPB;
+    m = 1 << (bi % 8);
+
+    if ((bp->data[bi / 8] & m) == 0) {
+        panic("freeing free block");
+    }
+
+    bp->data[bi / 8] &= ~m;
+    log_write(bp);
+    brelse(bp);
+}
+
+
+static void itrunc (struct inode *ip)
+{
+    int i, j;
+    struct buf *bp;
+    uint *a;
+
+    for (i = 0; i < NDIRECT; i++) {
+        if (ip->addrs[i]) {
+            bfree(ip->dev, ip->addrs[i]);
+            ip->addrs[i] = 0;
+        }
+    }
+
+    if (ip->addrs[NDIRECT]) {
+        bp = bread(ip->dev, ip->addrs[NDIRECT]);
+        a = (uint*) bp->data;
+
+        for (j = 0; j < NINDIRECT; j++) {
+            if (a[j]) {
+                bfree(ip->dev, a[j]);
+            }
+        }
+
+        brelse(bp);
+        bfree(ip->dev, ip->addrs[NDIRECT]);
+        ip->addrs[NDIRECT] = 0;
+    }
+
+    ip->size = 0;
+    iupdate(ip);
+}
+
+__code iput_inode_nolink(struct fs_impl* fs_impl, struct inode* ip, __code next(...)){
+    
+    if (ip->flags & I_BUSY) {
+        char* msg = "iput busy";
+        struct Err* err = createKernelError(&proc->cbc_context);
+        Gearef(cbc_context, Err)->msg = msg;
+        goto meta(cbc_context, err->panic);
+    }   
+        
+    ip->flags |= I_BUSY;
+    release(&icache.lock);
+    itrunc(ip);
+    ip->type = 0;
+    iupdate(ip);
+        
+    acquire(&icache.lock);
+    ip->flags = 0;
+    wakeup(ip); 
+    goto next(...);
+}
+
+__code readi_check_diskinode(struct fs_impl* fs_impl,struct inode* ip, char* dst, uint n, __code next(int ret, ...)){
+    if (ip->major < 0 || ip->major >= NDEV || !devsw[ip->major].read) {
+        ret = -1;
+        goto next(ret, ...);
+    }
+
+    ret = devsw[ip->major].read(ip, dst, n);
+    goto next(ret, ...);
+}
+
+__code readi_loopcheck(struct fs_impl* fs_impl, uint tot, uint m, char* dst, uint off, uint n, __code next(...)){
+    if(tot < n){
+        goto readi_loop(fs_impl, ip, bp, tot, m, dst, off, n, next(...));
+    }
+    goto readi_noloop(fs_impl, next(...));
+}
+
+static void bzero (int dev, int bno)
+{
+    struct buf *bp;
+
+    bp = bread(dev, bno);
+    memset(bp->data, 0, BSIZE);
+    log_write(bp);
+    brelse(bp);
+}
+
+static uint balloc (uint dev)
+{
+    int b, bi, m;
+    struct buf *bp;
+    struct superblock sb;
+
+    bp = 0;
+    readsb(dev, &sb);
+
+    for (b = 0; b < sb.size; b += BPB) {
+        bp = bread(dev, BBLOCK(b, sb.ninodes));
+
+        for (bi = 0; bi < BPB && b + bi < sb.size; bi++) {
+            m = 1 << (bi % 8);
+
+            if ((bp->data[bi / 8] & m) == 0) {  // Is block free?
+                bp->data[bi / 8] |= m;  // Mark block in use.
+                log_write(bp);
+                brelse(bp);
+                bzero(dev, b + bi);
+                return b + bi;
+            }
+        }
+
+        brelse(bp);
+    }
+
+    panic("balloc: out of blocks");
+}
+
+
+static uint bmap (struct inode *ip, uint bn)
+{
+    uint addr, *a;
+    struct buf *bp;
+
+    if (bn < NDIRECT) {
+        if ((addr = ip->addrs[bn]) == 0) {
+            ip->addrs[bn] = addr = balloc(ip->dev);
+        }
+
+        return addr;
+    }
+
+    bn -= NDIRECT;
+
+    if (bn < NINDIRECT) {
+        // Load indirect block, allocating if necessary.
+        if ((addr = ip->addrs[NDIRECT]) == 0) {
+            ip->addrs[NDIRECT] = addr = balloc(ip->dev);
+        }
+
+        bp = bread(ip->dev, addr);
+        a = (uint*) bp->data;
+
+        if ((addr = a[bn]) == 0) {
+            a[bn] = addr = balloc(ip->dev);
+            log_write(bp);
+        }
+
+        brelse(bp);
+        return addr;
+    }
+
+    panic("bmap: out of range");
+}
+
+
+__code readi_loop(struct fs_impl* fs_impl, struct inode* ip, struct buf* bp, uint tot, uint m, char* dst, uint off, uint n, __code next(...)){ //:skip
+    bp = bread(ip->dev, bmap(ip, off / BSIZE));
+    m = min(n - tot, BSIZE - off%BSIZE);
+    memmove(dst, bp->data + off % BSIZE, m);
+    brelse(bp);
+    tot += m;
+    off += m; 
+    dst += m;
+    goto readi_loopcheck(fs_impl, tot, m, dst, off, n, next(...));
+}
+
+__code readi_noloop(struct fs_impl* fs_impl, uint n, __code next(int ret, ...)){
+    ret = n;
+    goto next(ret, ...);
+}
+
+__code writei_check_diskinode(struct fs_impl* fs_impl,struct inode* ip, char* src, uint n, __code next(int ret, ...)){
+    if (ip->major < 0 || ip->major >= NDEV || !devsw[ip->major].write) {
+        ret = -1;
+        goto next(ret, ...);
+    }
+
+    ret = devsw[ip->major].write(ip, src, n);
+    goto next(ret, ...);
+}
+
+__code writei_loopcheck(struct fs_impl* fs_impl, uint tot, uint m, char* src, uint off, uint n, __code next(...)){
+    if(tot < n){
+        goto writei_loop(fs_impl, ip, bp, tot, m, src, off, n, next(...));
+    }
+    goto writei_noloop(fs_impl, next(...));
+}
+
+__code writei_loop(struct fs_impl* fs_impl, struct inode* ip, struct buf* bp, uint tot, uint m, char* src, uint off, uint n, __code next(...)){ //:skip
+    bp = bread(ip->dev, bmap(ip, off / BSIZE));
+    m = min(n - tot, BSIZE - off%BSIZE); 
+    memmove(bp->data + off % BSIZE, src, m);
+    log_write(bp);
+    brelse(bp);
+    tot += m;
+    off += m;
+    src += m;
+    goto writei_loopcheck(fs_impl, tot, m, src, off, n, next(...));
+}
+
+__code writei_noloop(struct fs_impl* fs_impl, struct inode* ip, uint n, uint off, __code next(int ret, ...)){
+    if (n > 0 && off > ip->size) {
+        ip->size = off;
+        iupdate(ip);
+    }
+    ret = n;
+    goto next(ret, ...);
+}
+typedef struct dirent dirent;
+__code dirlookup_loopcheck(struct fs_impl* fs_impl, struct inode* dp, char* name, uint off, uint* poff, dirent* de, __code next(...)){ //:skip
+    if(off < dp->size){
+        goto dirlookup_loop(fs_impl, dp, name, off, inum, poff, de, next(...));
+    }
+    goto dirlookup_noloop(fs_impl, next(...));
+}
+
+__code dirlookup_loop(struct fs_impl* fs_impl, struct inode* dp, char* name, uint off, uint inum, uint* poff, dirent* de, __code next(int ret, ...)){
+    if (readi(dp, (char*) &de, off, sizeof(de)) != sizeof(de)) {
+        char* msg = "dirlink read";
+        struct Err* err = createKernelError(&proc->cbc_context);
+        Gearef(cbc_context, Err)->msg = msg;
+        goto meta(cbc_context, err->panic);
+    }
+
+    if (de->inum == 0) {
+        off += sizeof(de);
+        goto dirlookup_loopcheck(fs_impl, dp, name, poff, de, next(...));
+    }
+
+    if (namecmp(name, de->name) == 0) {
+        // entry matches path element
+        if (poff) {
+            *poff = off;
+        }
+
+        inum = de->inum;
+        ret = iget(dp->dev, inum);
+        goto next(ret, ...);
+    }
+
+    off += sizeof(de);
+    goto dirlookup_loopcheck(fs_impl, dp, name, poff, de, next(...));
+}
+
+__code dirlookup_noloop(struct fs_impl* fs_impl, __code next(int ret, ...)){
+    ret = 0;
+    goto next(ret, ...);
+}
+
+__code dirlink_namecheck(struct fs_impl* fs_impl, struct inode* ip, __code next(int ret, ...)){
+    iput(ip);
+    ret = -1;
+    goto next(ret, ...);
+}
+
+__code dirlink_loopcheck(struct fs_impl* fs_impl, struct dirent* de, struct inode* dp, uint off, __code next(...)){ //:skip
+    if(off < dp->size){
+        goto dirlink_loop(fs_impl, de, dp, off, inum, next(...));
+    }
+    goto dirlink_noloop(fs_impl, de, dp, off, inum, name, next(...));
+}
+
+__code dirlink_loop(struct fs_impl* fs_impl, struct dirent* de, struct inode* dp, uint off, uint inum, __code next(...)){ //:skip
+    if (readi(dp, (char*) &de, off, sizeof(de)) != sizeof(de)) {
+       char* msg = "dirlink read";
+       struct Err* err = createKernelError(&proc->cbc_context);
+       Gearef(cbc_context, Err)->msg = msg;
+       goto meta(cbc_context, err->panic);
+    }
+
+    if (de->inum == 0) {
+        goto dirlink_noloop(fs_impl, de, dp, off, inum, name, next(...));
+    }
+    
+    goto dirlink_loopcheck(fs_impl, de, dp, off + sizeof(de), next(...));
+}
+
+__code dirlink_noloop(struct fs_impl* fs_impl, struct dirent* de, struct inode* dp, uint off, uint inum, char* name, __code next(int ret, ...)){ //:skip
+    strncpy(de->name, name, DIRSIZ);
+    de->inum = inum;
+
+    if (writei(dp, (char*) &de, off, sizeof(de)) != sizeof(de)) {
+       char* msg = "dirlink read";
+       struct Err* err = createKernelError(&proc->cbc_context);
+       Gearef(cbc_context, Err)->msg = msg;
+       goto meta(cbc_context, err->panic);
+    }
+    ret = 0;
+    goto next(ret, ...);
+}