Replace I_BUSY with sleep locks

dec637bc · Frans Kaashoek · 2adb7c21 · dec637bc · dec637bc · dec637bc
--- a/console.c
+++ b/console.c
@@ -7,6 +7,7 @@
 #include "param.h"
 #include "traps.h"
 #include "spinlock.h"
+#include "sleeplock.h"
 #include "fs.h"
 #include "file.h"
 #include "memlayout.h"

--- a/file.c
+++ b/file.c
@@ -6,8 +6,9 @@
 #include "defs.h"
 #include "param.h"
 #include "fs.h"
-#include "file.h"
 #include "spinlock.h"
+#include "sleeplock.h"
+#include "file.h"

 struct devsw devsw[NDEV];
 struct {

--- a/file.h
+++ b/file.h
@@ -14,7 +14,8 @@ struct inode {
  uint dev;           // Device number
  uint inum;          // Inode number
  int ref;            // Reference count
-  int flags;          // I_BUSY, I_VALID
+  struct sleeplock lock;
+  int flags;          // I_VALID

  short type;         // copy of disk inode
  short major;
@@ -23,7 +24,6 @@ struct inode {
  uint size;
  uint addrs[NDIRECT+1];
 };
-#define I_BUSY 0x1
 #define I_VALID 0x2

 // table mapping major device number to

--- a/fs.c
+++ b/fs.c
@@ -135,9 +135,7 @@ bfree(int dev, uint b)
 //
 // * Locked: file system code may only examine and modify
 //   the information in an inode and its content if it
-//   has first locked the inode. The I_BUSY flag indicates
-//   that the inode is locked. ilock() sets I_BUSY,
-//   while iunlock clears it.
+//   has first locked the inode.
 //
 // Thus a typical sequence is:
 //   ip = iget(dev, inum)
@@ -165,7 +163,13 @@ struct {
 void
 iinit(int dev)
 {
+  int i = 0;
+  
  initlock(&icache.lock, "icache");
+  for(i = 0; i < NINODE; i++) {
+    initsleeplock(&icache.inode[i].lock, "inode");
+  }
+  
  readsb(dev, &sb);
  cprintf("sb: size %d nblocks %d ninodes %d nlog %d logstart %d\
 inodestart %d bmap start %d\n", sb.size, sb.nblocks,
@@ -277,11 +281,7 @@ ilock(struct inode *ip)
  if(ip == 0 || ip->ref < 1)
    panic("ilock");

-  acquire(&icache.lock);
-  while(ip->flags & I_BUSY)
-    sleep(ip, &icache.lock);
-  ip->flags |= I_BUSY;
-  release(&icache.lock);
+  acquiresleep(&ip->lock);

  if(!(ip->flags & I_VALID)){
    bp = bread(ip->dev, IBLOCK(ip->inum, sb));
@@ -303,13 +303,10 @@ ilock(struct inode *ip)
 void
 iunlock(struct inode *ip)
 {
-  if(ip == 0 || !(ip->flags & I_BUSY) || ip->ref < 1)
+  if(ip == 0 || !holdingsleep(&ip->lock) || ip->ref < 1)
    panic("iunlock");

-  acquire(&icache.lock);
-  ip->flags &= ~I_BUSY;
-  wakeup(ip);
-  release(&icache.lock);
+  releasesleep(&ip->lock);
 }

 // Drop a reference to an in-memory inode.
@@ -325,16 +322,12 @@ iput(struct inode *ip)
  acquire(&icache.lock);
  if(ip->ref == 1 && (ip->flags & I_VALID) && ip->nlink == 0){
    // inode has no links and no other references: truncate and free.
-    if(ip->flags & I_BUSY)
-      panic("iput busy");
-    ip->flags |= I_BUSY;
    release(&icache.lock);
    itrunc(ip);
    ip->type = 0;
    iupdate(ip);
    acquire(&icache.lock);
    ip->flags = 0;
-    wakeup(ip);
  }
  ip->ref--;
  release(&icache.lock);

--- a/pipe.c
+++ b/pipe.c
@@ -4,8 +4,9 @@
 #include "mmu.h"
 #include "proc.h"
 #include "fs.h"
-#include "file.h"
 #include "spinlock.h"
+#include "sleeplock.h"
+#include "file.h"

 #define PIPESIZE 512


--- a/sysfile.c
+++ b/sysfile.c
@@ -11,6 +11,8 @@
 #include "mmu.h"
 #include "proc.h"
 #include "fs.h"
+#include "spinlock.h"
+#include "sleeplock.h"
 #include "file.h"
 #include "fcntl.h"


--- a/uart.c
+++ b/uart.c
@@ -5,6 +5,7 @@
 #include "param.h"
 #include "traps.h"
 #include "spinlock.h"
+#include "sleeplock.h"
 #include "fs.h"
 #include "file.h"
 #include "mmu.h"