1 files changed, 11 insertions, 10 deletions

diff --git a/lib/std/fs/file.zig b/lib/std/fs/file.zig
index 8d4f5df2e8..e0795f4c1c 100644
--- a/lib/std/fs/file.zig
+++ b/lib/std/fs/file.zig
@@ -615,7 +615,7 @@ pub const File = struct {
         }
     }
 
-    pub fn pwritev(self: File, iovecs: []os.iovec_const, offset: usize) PWriteError!usize {
+    pub fn pwritev(self: File, iovecs: []os.iovec_const, offset: u64) PWriteError!usize {
         if (is_windows) {
             // TODO improve this to use WriteFileScatter
             if (iovecs.len == 0) return @as(usize, 0);
@@ -632,11 +632,11 @@ pub const File = struct {
 
     /// The `iovecs` parameter is mutable because this function needs to mutate the fields in
     /// order to handle partial writes from the underlying OS layer.
-    pub fn pwritevAll(self: File, iovecs: []os.iovec_const, offset: usize) PWriteError!void {
+    pub fn pwritevAll(self: File, iovecs: []os.iovec_const, offset: u64) PWriteError!void {
         if (iovecs.len == 0) return;
 
         var i: usize = 0;
-        var off: usize = 0;
+        var off: u64 = 0;
         while (true) {
             var amt = try self.pwritev(iovecs[i..], offset + off);
             off += amt;
@@ -652,24 +652,25 @@ pub const File = struct {
 
     pub const CopyRangeError = os.CopyFileRangeError;
 
-    pub fn copyRange(in: File, in_offset: u64, out: File, out_offset: u64, len: usize) CopyRangeError!usize {
-        return os.copy_file_range(in.handle, in_offset, out.handle, out_offset, len, 0);
+    pub fn copyRange(in: File, in_offset: u64, out: File, out_offset: u64, len: u64) CopyRangeError!usize {
+        const adjusted_len = math.cast(usize, len) catch math.maxInt(usize);
+        return os.copy_file_range(in.handle, in_offset, out.handle, out_offset, adjusted_len, 0);
     }
 
     /// Returns the number of bytes copied. If the number read is smaller than `buffer.len`, it
     /// means the in file reached the end. Reaching the end of a file is not an error condition.
-    pub fn copyRangeAll(in: File, in_offset: u64, out: File, out_offset: u64, len: usize) CopyRangeError!usize {
-        var total_bytes_copied: usize = 0;
+    pub fn copyRangeAll(in: File, in_offset: u64, out: File, out_offset: u64, len: u64) CopyRangeError!usize {
+        var total_bytes_copied: u64 = 0;
         var in_off = in_offset;
         var out_off = out_offset;
         while (total_bytes_copied < len) {
-            const amt_copied = try copyRange(in, in_off, out, out_off, len - total_bytes_copied);
-            if (amt_copied == 0) return total_bytes_copied;
+            const amt_copied = try copyRange(in, in_off, out, out_off, len);
+            if (amt_copied == 0) return @intCast(usize, total_bytes_copied);
             total_bytes_copied += amt_copied;
             in_off += amt_copied;
             out_off += amt_copied;
         }
-        return total_bytes_copied;
+        return @intCast(usize, total_bytes_copied);
     }
 
     pub const WriteFileOptions = struct {