lab mmap: finish

1 files changed, 31 insertions, 0 deletions

diff --git a/kernel/file.c b/kernel/file.c
index 0fba21b..add6575 100644
--- a/kernel/file.c
+++ b/kernel/file.c
@@ -6,6 +6,7 @@
 #include "riscv.h"
 #include "defs.h"
 #include "param.h"
+#include "fcntl.h"
 #include "fs.h"
 #include "spinlock.h"
 #include "sleeplock.h"
@@ -197,3 +198,33 @@ filewrite(struct file *f, uint64 addr, int n)
   return ret;
 }
 
+int fileperm(struct file* f)
+{
+  int flags = 0;
+  if(f->writable)
+    flags |= PROT_WRITE;
+  if(f->readable)
+    flags |= PROT_READ;
+  return flags;
+}
+
+// reads file from disk to physical address, needed by mmap
+int mmap_read(struct file *file, uint64 pa, uint64 off, int size) {
+  int n = 0;
+  ilock(file->ip);
+  n = readi(file->ip, 0, pa, off, size);
+  off += n;
+  iunlock(file->ip);
+  return off;
+}
+
+// writes from virtual address to disk, needed by munmap
+int munmap_write(struct file *file, uint64 va, uint64 off, int size) {
+  int r;
+  begin_op();
+  ilock(file->ip);
+  r = writei(file->ip, 1, va, off, size);
+  iunlock(file->ip);
+  end_op();
+  return r;
+}