From eaea18cb9cbb86018dae8f1decfa217ecbe85fa5 Mon Sep 17 00:00:00 2001
From: rsc <rsc>
Date: Wed, 22 Aug 2007 06:01:32 +0000
Subject: PDF at http://am.lcs.mit.edu/~rsc/xv6.pdf

Various changes made while offline.

 + bwrite sector argument is redundant; use b->sector.
 + reformatting of files for nicer PDF page breaks
 + distinguish between locked, unlocked inodes in type signatures
 + change FD_FILE to FD_INODE
 + move userinit (nee proc0init) to proc.c
 + move ROOTDEV to param.h
 + always parenthesize sizeof argument
---
 file.c | 38 +++++++++++++++++++++-----------------
 1 file changed, 21 insertions(+), 17 deletions(-)

(limited to 'file.c')

diff --git a/file.c b/file.c
index 47e4629..981d474 100644
--- a/file.c
+++ b/file.c
@@ -11,9 +11,8 @@
 #include "fs.h"
 #include "fsvar.h"
 
-struct spinlock file_table_lock;
 struct devsw devsw[NDEV];
-
+struct spinlock file_table_lock;
 struct file file[NFILE];
 
 void
@@ -22,7 +21,7 @@ fileinit(void)
   initlock(&file_table_lock, "file_table");
 }
 
-// Allocate a file structure
+// Allocate a file structure.
 struct file*
 filealloc(void)
 {
@@ -57,16 +56,17 @@ int
 fileread(struct file *f, char *addr, int n)
 {
   int r;
+  struct inode *ip;
 
   if(f->readable == 0)
     return -1;
   if(f->type == FD_PIPE)
     return pipe_read(f->pipe, addr, n);
-  if(f->type == FD_FILE){
-    ilock(f->ip);
-    if((r = readi(f->ip, addr, f->off, n)) > 0)
+  if(f->type == FD_INODE){
+    ip = ilock(f->ip);
+    if((r = readi(ip, addr, f->off, n)) > 0)
       f->off += r;
-    iunlock(f->ip);
+    iunlock(ip);
     return r;
   }
   panic("fileread");
@@ -77,16 +77,17 @@ int
 filewrite(struct file *f, char *addr, int n)
 {
   int r;
+  struct inode *ip;
 
   if(f->writable == 0)
     return -1;
   if(f->type == FD_PIPE)
     return pipe_write(f->pipe, addr, n);
-  if(f->type == FD_FILE){
-    ilock(f->ip);
-    if((r = writei(f->ip, addr, f->off, n)) > 0)
+  if(f->type == FD_INODE){
+    ip = ilock(f->ip);
+    if((r = writei(ip, addr, f->off, n)) > 0)
       f->off += r;
-    iunlock(f->ip);
+    iunlock(ip);
     return r;
   }
   panic("filewrite");
@@ -96,10 +97,12 @@ filewrite(struct file *f, char *addr, int n)
 int
 filestat(struct file *f, struct stat *st)
 {
-  if(f->type == FD_FILE){
-    ilock(f->ip);
-    stati(f->ip, st);
-    iunlock(f->ip);
+  struct inode *ip;
+
+  if(f->type == FD_INODE){
+    ip = ilock(f->ip);
+    stati(ip, st);
+    iunlock(ip);
     return 0;
   }
   return -1;
@@ -110,6 +113,7 @@ void
 fileclose(struct file *f)
 {
   struct file ff;
+
   acquire(&file_table_lock);
 
   if(f->ref < 1 || f->type == FD_CLOSED)
@@ -127,8 +131,8 @@ fileclose(struct file *f)
   
   if(ff.type == FD_PIPE)
     pipe_close(ff.pipe, ff.writable);
-  else if(ff.type == FD_FILE)
-    idecref(ff.ip);
+  else if(ff.type == FD_INODE)
+    iput(ff.ip);
   else
     panic("fileclose");
 }
-- 
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