diff --git a/fd.c b/fd.c
index 2b4db0e254188b62b94eb4cfa09e8941931ec97d..7e7502fee63eade0ce022194d21a60738d033f44 100644
--- a/fd.c
+++ b/fd.c
@@ -58,7 +58,7 @@ fd_alloc(void)
 int
 fd_write(struct fd *fd, char *addr, int n)
 {
-  if(fd->writeable == 0)
+  if(fd->writable == 0)
     return -1;
   if(fd->type == FD_PIPE){
     return pipe_write(fd->pipe, addr, n);
@@ -114,7 +114,7 @@ fd_close(struct fd *fd)
     release(&fd_table_lock);
 
     if(dummy.type == FD_PIPE){
-      pipe_close(dummy.pipe, dummy.writeable);
+      pipe_close(dummy.pipe, dummy.writable);
     } else if(dummy.type == FD_FILE){
       idecref(dummy.ip);
     } else {
diff --git a/fd.h b/fd.h
index 1be1cf09bb54701e6b777b91650b0311c3140773..93f43bb72251c30ce9c6a88050ba186eeded4907 100644
--- a/fd.h
+++ b/fd.h
@@ -2,7 +2,7 @@ struct fd {
   enum { FD_CLOSED, FD_NONE, FD_PIPE, FD_FILE } type;
   int ref; // reference count
   char readable;
-  char writeable;
+  char writable;
   struct pipe *pipe;
   struct inode *ip;
   uint off;
diff --git a/kalloc.c b/kalloc.c
index 83338c7a075220cce08c88a3f2c11e7a684dc76f..34a55eb40f610b3aeba4082306bd1723ea4299df 100644
--- a/kalloc.c
+++ b/kalloc.c
@@ -51,7 +51,7 @@ kfree(char *cp, int len)
   if(len % PAGE)
     panic("kfree");
 
-  // XXX fill with junk to help debug
+  // Fill with junk to catch dangling refs.
   for(i = 0; i < len; i++)
     cp[i] = 1;
 
diff --git a/pipe.c b/pipe.c
index 6df4fbf3dd5f3fb52b196817aeb6845c5b87e714..a1c900159267aa6edbe036d2ed356dd540bb8802 100644
--- a/pipe.c
+++ b/pipe.c
@@ -37,11 +37,11 @@ pipe_alloc(struct fd **fd1, struct fd **fd2)
   initlock(&p->lock, "pipe");
   (*fd1)->type = FD_PIPE;
   (*fd1)->readable = 1;
-  (*fd1)->writeable = 0;
+  (*fd1)->writable = 0;
   (*fd1)->pipe = p;
   (*fd2)->type = FD_PIPE;
   (*fd2)->readable = 0;
-  (*fd2)->writeable = 1;
+  (*fd2)->writable = 1;
   (*fd2)->pipe = p;
   return 0;
  oops:
@@ -59,11 +59,11 @@ pipe_alloc(struct fd **fd1, struct fd **fd2)
 }
 
 void
-pipe_close(struct pipe *p, int writeable)
+pipe_close(struct pipe *p, int writable)
 {
   acquire(&p->lock);
 
-  if(writeable){
+  if(writable){
     p->writeopen = 0;
     wakeup(&p->readp);
   } else {
diff --git a/syscall.c b/syscall.c
index a85dc674336a920ebf6f69f8338fe8956cf8dccb..c6d459916696bf0ba63ca4d95048c4f94bb191e2 100644
--- a/syscall.c
+++ b/syscall.c
@@ -260,13 +260,13 @@ sys_open(void)
   fd->type = FD_FILE;
   if(arg1 & O_RDWR) {
     fd->readable = 1;
-    fd->writeable = 1;
+    fd->writable = 1;
   } else if(arg1 & O_WRONLY) {
     fd->readable = 0;
-    fd->writeable = 1;
+    fd->writable = 1;
   } else {
     fd->readable = 1;
-    fd->writeable = 0;
+    fd->writable = 0;
   }
   fd->ip = ip;
   fd->off = 0;