diff --git a/kernel/driver/buf.c b/kernel/driver/buf.c
index 891db33f0a59c905d9ee41cfaf0cd3f2fc83cedd..50469ae137efdc8450bf4327872d6e613931e071 100755
--- a/kernel/driver/buf.c
+++ b/kernel/driver/buf.c
@@ -1,108 +1,108 @@
-#include "buf.h"
-#include "../sdcard/sd.h"
-#include "../sdcard/disk.h"
-#include "../lock/sleeplock.h"
-#include "../lock/spinlock.h"
-#include "../libs/print.h"
-
-
-
-struct {
-    struct spinlock lock;
-    struct buf buf[BUFNUM];
-    struct buf head;
-} bcache;
-
-void binit()
-{
-    struct buf *b;
-    bcache.head.prev = &bcache.head;
-    bcache.head.next = &bcache.head;
-    for(b = bcache.buf;b < bcache.buf+BUFNUM;b++){
-        b->refcnt = 0;
-        b->sectorno = ~0;
-        b->dev = ~0;
-        b->next = bcache.head.next;
-        b->prev = &bcache.head;
-        createsleeplock(&b->lock,"buffer");
-        bcache.head.next->prev = b;
-        bcache.head.next = b;
-    }
-    printf("binit!\n");
-}
-
-static struct buf* bget(uint dev,uint sectorno)
-{
-    struct buf *b;
-    lock(&bcache.lock);
-    for(b = bcache.head.next;b != &bcache.head;b = b->next){
-        if(b->dev == dev && b->sectorno == sectorno){
-            b->refcnt++;
-            unlock(&bcache.lock);
-            locksleep(&b->lock);
-            return b;
-        }
-    }
-    for(b = bcache.head.prev;b != &bcache.head;b = b->prev){
-        if(b->refcnt == 0){
-            b->dev = dev;
-            b->sectorno = sectorno;
-            b->valid = 0;
-            b->refcnt = 1;
-            unlock(&bcache.lock);
-            locksleep(&b->lock);
-            return b;
-        }
-    }
-    panic("bget: no buffers!");
-    return NULL;
-}
-
-struct buf* bread(uint dev,uint sectorno)
-{
-    struct buf *b;
-    b = bget(dev,sectorno);
-    if(b->valid == 0){
-        disk_read(b);
-        b->valid = 1;
-    }
-    return b;
-}
-
-void bwrite(struct buf *b)
-{
-    if(!holdingsleep(&b->lock)){
-        panic("bwrite");
-    }
-    disk_write(b);
-}
-
-void brelse(struct buf *b){
-    if(!holdingsleep(&b->lock)){
-        panic("panic:brelse!");
-    }
-    unlocksleep(&b->lock);
-    lock(&bcache.lock);
-    b->refcnt--;
-    if(b->refcnt == 0){
-        b->next->prev = b->prev;
-        b->prev->next = b->next;
-        b->next = bcache.head.next;
-        b->prev = &bcache.head;
-        bcache.head.next->prev = b;
-        bcache.head.next = b;
-    }
-    unlock(&bcache.lock);
-}
-
-void bpin(struct buf *b){
-    lock(&bcache.lock);
-    b->refcnt++;
-    unlock(&bcache.lock);
-}
-
-void bunpin(struct buf *b){
-    lock(&bcache.lock);
-    b->refcnt--;
-    unlock(&bcache.lock);
-}
+#include "buf.h"
+#include "../sdcard/sd.h"
+#include "../sdcard/disk.h"
+#include "../lock/sleeplock.h"
+#include "../lock/spinlock.h"
+#include "../libs/print.h"
+//123
+
+
+struct {
+    struct spinlock lock;
+    struct buf buf[BUFNUM];
+    struct buf head;
+} bcache;
+
+void binit()
+{
+    struct buf *b;
+    bcache.head.prev = &bcache.head;
+    bcache.head.next = &bcache.head;
+    for(b = bcache.buf;b < bcache.buf+BUFNUM;b++){
+        b->refcnt = 0;
+        b->sectorno = ~0;
+        b->dev = ~0;
+        b->next = bcache.head.next;
+        b->prev = &bcache.head;
+        createsleeplock(&b->lock,"buffer");
+        bcache.head.next->prev = b;
+        bcache.head.next = b;
+    }
+    printf("binit!\n");
+}
+
+static struct buf* bget(uint dev,uint sectorno)
+{
+    struct buf *b;
+    lock(&bcache.lock);
+    for(b = bcache.head.next;b != &bcache.head;b = b->next){
+        if(b->dev == dev && b->sectorno == sectorno){
+            b->refcnt++;
+            unlock(&bcache.lock);
+            locksleep(&b->lock);
+            return b;
+        }
+    }
+    for(b = bcache.head.prev;b != &bcache.head;b = b->prev){
+        if(b->refcnt == 0){
+            b->dev = dev;
+            b->sectorno = sectorno;
+            b->valid = 0;
+            b->refcnt = 1;
+            unlock(&bcache.lock);
+            locksleep(&b->lock);
+            return b;
+        }
+    }
+    panic("bget: no buffers!");
+    return NULL;
+}
+
+struct buf* bread(uint dev,uint sectorno)
+{
+    struct buf *b;
+    b = bget(dev,sectorno);
+    if(b->valid == 0){
+        disk_read(b);
+        b->valid = 1;
+    }
+    return b;
+}
+
+void bwrite(struct buf *b)
+{
+    if(!holdingsleep(&b->lock)){
+        panic("bwrite");
+    }
+    disk_write(b);
+}
+
+void brelse(struct buf *b){
+    if(!holdingsleep(&b->lock)){
+        panic("panic:brelse!");
+    }
+    unlocksleep(&b->lock);
+    lock(&bcache.lock);
+    b->refcnt--;
+    if(b->refcnt == 0){
+        b->next->prev = b->prev;
+        b->prev->next = b->next;
+        b->next = bcache.head.next;
+        b->prev = &bcache.head;
+        bcache.head.next->prev = b;
+        bcache.head.next = b;
+    }
+    unlock(&bcache.lock);
+}
+
+void bpin(struct buf *b){
+    lock(&bcache.lock);
+    b->refcnt++;
+    unlock(&bcache.lock);
+}
+
+void bunpin(struct buf *b){
+    lock(&bcache.lock);
+    b->refcnt--;
+    unlock(&bcache.lock);
+}